JP4293184B2 - Hybrid vehicle and control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To favorably suppress deterioration of a catalyst for exhaust gas purification by proper increase of a fuel supply amount to an internal combustion engine. <P>SOLUTION: In the hybrid automobile 20, when a detected or estimated catalyst bed temperature Tcat is a reference temperature Tref or more, an input limit Win is a temporary limit value Win0 or less, and a fuel is cut when a map for first OT increase coefficient setting should be set, it is assumed that the catalyst bed temperature Tcat has entered a predetermined high temperature zone where catalyst deterioration may be caused during the fuel cut. In such a case, a map for second OT increase coefficient setting is set having a tendency to increase a fuel injection amount for a predetermined time thereafter (steps S230, S240, S280-S320). <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to a hybrid vehicle and a control method thereof.

Conventionally, as an example of a hybrid vehicle, one in which a motor generator is disposed between a torque converter that transmits power of an internal combustion engine to a drive shaft and an automatic transmission is known (for example, see Patent Document 1). In this hybrid vehicle, when it is determined that the temperature of the catalyst is higher than a predetermined determination reference value, the internal combustion engine is to suppress deterioration of the catalyst due to exposure to a lean atmosphere at a high temperature. Control for suppressing the fuel cut is executed. That is, in this hybrid vehicle, when the catalyst is in a high temperature state, the fuel cut is prohibited even if a deceleration request based on the accelerator off or the like is made under a predetermined condition, to compensate for the decrease in the deceleration accompanying the prohibition of the fuel cut. A regenerative braking force is generated by the motor generator, and the regenerative power is stored in a power storage device such as a secondary battery. Further, in this hybrid vehicle, when a deceleration request is made based on the accelerator off or the like when the catalyst is in a high temperature state, the regenerative power by the motor generator may exceed the allowable charging power that is the allowable power for charging the power storage device. If there is, the required braking force is generated by the hydraulic brake instead of the regenerative braking force by the motor generator. Conventionally, as an example of a hybrid vehicle, in order to suppress deterioration of an exhaust gas purification catalyst that is mainly in a high temperature state by being exposed to a lean atmosphere, when the engine is stopped due to intermittent operation of the engine or the like. In addition, after performing a fuel increasing process for increasing the amount of fuel supplied to the combustion chamber as compared with the conventional state, a process for stopping the fuel supply is known (see, for example, Patent Document 2). ).
JP 2003-207043 A JP 2004-176710 A

  As described above, in the hybrid vehicle, when there is a possibility that the regenerative power exceeds the allowable charging power of the power storage device when the deceleration request is made, the braking force required by the hydraulic brake is used instead of the regenerative braking force by the motor generator. If generated, fuel cut in the internal combustion engine can be prohibited in order to suppress the deterioration of the catalyst even in a high temperature state. However, it is not easy to quickly generate the deceleration force based on the accelerator off by the hydraulic brake, and the control becomes complicated, so if the regenerative power may exceed the allowable charging power, the fuel cut is allowed as much as possible. Thus, it is preferable to obtain a braking force by the engine brake. In order to suppress the deterioration of the catalyst even if the prohibition of fuel cut is canceled from the relationship with the allowable charging power of the power storage device in this way, the prohibition of fuel cutting is canceled based on the allowable charging power. By the time, it is preferable to adjust the temperature of the catalyst by increasing the fuel supply amount. However, the timing at which prohibition of fuel cut based on allowable charging power is to be changed varies depending on various conditions. Further, when the prohibition of fuel cut is canceled from the relationship with the chargeable power, and the fuel cut is once executed thereafter, the catalyst is heated by being exposed to a lean atmosphere. The timing and frequency at which the accelerator is turned off by the driver and the braking force required when the accelerator is turned off vary depending on various conditions. Depending on the driver's request, frequent fuel cuts must be performed. There may be cases where it is not obtained. Therefore, if the amount of fuel supply is simply increased, there is a possibility that the catalyst cannot be brought into a state in which deterioration can be suppressed when the prohibition of fuel cut is canceled due to the relationship with the allowable charging power of the power storage device.

  Accordingly, an object of the hybrid vehicle and the control method thereof according to the present invention is to satisfactorily suppress the deterioration of the exhaust gas purification catalyst by appropriately increasing the amount of fuel supplied to the internal combustion engine. Another object of the hybrid vehicle and its control method according to the present invention is to satisfactorily suppress the deterioration of the exhaust gas purification catalyst even when the frequency of stopping the fuel supply to the internal combustion engine increases.

  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
An internal combustion engine;
Purification means including a catalyst for purifying exhaust gas discharged from the internal combustion engine;
Catalyst high temperature history determination means for determining whether or not the temperature of the catalyst has entered a predetermined high temperature range that may cause deterioration of the catalyst when fuel supply to the internal combustion engine is stopped;
Power power input / output means connected to the first axle as one of the axles and the output shaft of the internal combustion engine and capable of inputting / outputting power to / from the first axle and the output shaft with input / output of power and power When,
An electric motor capable of inputting / outputting power to / from a second axle that is either the first axle or an axle different from the first axle;
Power storage means capable of exchanging power between the power drive input / output means and the electric motor;
Charge allowable power setting means for setting charge allowable power that is power allowed for charging of the power storage means based on the state of the power storage means;
Fuel supply stop determination means for determining whether or not to stop the fuel supply to the internal combustion engine based on the set allowable charge power;
One of the increase constraints based on the set charge allowable power is selected from among a plurality of increase constraints that respectively define an increase in the amount of fuel supplied to the internal combustion engine for adjusting the temperature of the catalyst. On the other hand, when it is determined that the temperature of the catalyst has entered the high temperature range, a predetermined increase that tends to increase the fuel supply amount as the execution increase constraint until a predetermined release condition is satisfied An increase restriction setting means for setting a restriction;
A required driving force setting means for setting a required driving force required for traveling;
Based on the determination result by the fuel supply stop determination means, the internal combustion engine is operated with the increase in the fuel supply amount in accordance with the set execution increase constraint, and based on the set required driving force Control means for controlling the internal combustion engine, the power drive input / output means and the electric motor so that a driving force is output;
Is provided.

  In this hybrid vehicle, a plurality of increase restrictions that respectively define an increase in the amount of fuel supplied to the internal combustion engine for adjusting the temperature of the catalyst based on the allowable charging power set as the allowable power for charging the power storage means Any increase restriction is set as an execution increase restriction, but when it is determined that the temperature of the catalyst has entered a predetermined high temperature range that may cause deterioration of the catalyst when the fuel supply to the internal combustion engine is stopped. Then, a predetermined increase restriction having a tendency to increase the fuel supply amount is set as the execution increase restriction until the predetermined release condition is satisfied. Then, the internal combustion engine is operated with an increase in the fuel supply amount in accordance with the set execution increase constraint according to the determination result of whether or not to stop the fuel supply based on the charge allowable power, The internal combustion engine, the power drive input / output means, and the electric motor are controlled so that a driving force based on the required driving force required for traveling is output. As described above, when the history that the temperature of the catalyst of the purifying means has entered the high temperature range is recognized, the fuel supply amount tends to be increased as the execution increase restriction until the predetermined release condition is satisfied. If the increase restriction is set, it is possible to supply more fuel to the internal combustion engine according to the predetermined increase restriction to suppress the temperature increase of the exhaust gas purification catalyst, or to lower the catalyst temperature. Thereafter, the prohibition of the stop of the fuel supply is canceled based on the allowable charge power, and the deterioration of the catalyst can be satisfactorily suppressed when the fuel supply is stopped.

  Further, in the hybrid vehicle according to the present invention, the fuel supply stop determination means determines that the stop of the fuel supply should be prohibited when the set charge allowable power is equal to or higher than a predetermined limit value as the charge power, The fuel increase constraint setting means sets the first increase constraint as the execution increase constraint when the set charge allowable power is equal to or greater than a temporary limit value which is a value larger than the limit value as the charge power. On the other hand, when the set allowable charging power is less than the temporary limit value as the charging power, the second fuel supply amount tends to increase as the execution increase constraint as compared with the first increase constraint. An increase restriction is set, and when it is determined that the temperature of the catalyst has entered the high temperature range even if the set allowable charging power is equal to or greater than the temporary limit value, the release condition is satisfied. It may be configured to set the second increase restriction as extenders constraint for the run to.

  Further, in the hybrid vehicle according to the present invention, the catalyst high temperature history determination means stops the fuel supply to the internal combustion engine when any increase restriction should be set as the execution increase restriction by the increase restriction setting means. The temperature of the catalyst may be determined to have entered the high temperature range. That is, when any of the increase constraints is to be set as the execution increase constraint by the increase constraint setting means, the temperature of the catalyst has increased to some extent. In such a case, if the fuel supply to the internal combustion engine is stopped, the catalyst This temperature tends to enter a high temperature range where the catalyst may be deteriorated when the fuel supply to the internal combustion engine is stopped. Therefore, if the fuel supply to the internal combustion engine is stopped when any increase restriction should be set as the execution increase restriction by the increase restriction setting means, the temperature of the catalyst is regarded as having entered the high temperature range, and thereafter By setting a predetermined increase restriction that tends to increase the fuel supply amount as an execution increase restriction until the predetermined release condition is satisfied, more fuel is supplied to the internal combustion engine when the fuel supply is resumed. It is possible to suppress the increase in the temperature of the exhaust gas purifying catalyst or to decrease the temperature of the catalyst. Accordingly, the prohibition of the stop of the fuel supply to the internal combustion engine is canceled based on the charge allowable power, and the deterioration of the catalyst can be satisfactorily suppressed after the fuel supply is stopped.

  Further, the release condition may be satisfied when a predetermined time or more has elapsed since the fuel supply to the internal combustion engine was stopped. As a result, once the fuel supply to the internal combustion engine is stopped, a predetermined increase restriction with a tendency to increase the fuel supply amount is continuously set for a predetermined time, so the fuel supply is resumed. It is sometimes possible to supply more fuel to the internal combustion engine to suppress an increase in the temperature of the catalyst of the purification means, or to lower the temperature of the catalyst. Therefore, even if the fuel supply is stopped again in a relatively short time after the fuel supply is temporarily stopped, that is, even if the frequency of stopping the fuel supply is increased, the deterioration of the exhaust gas purification catalyst is improved. It becomes possible to suppress.

  Furthermore, the hybrid vehicle according to the present invention may further include catalyst temperature acquisition means for acquiring the temperature of the catalyst, wherein the fuel supply stop determination means is configured such that the acquired catalyst temperature is equal to or higher than a predetermined temperature, and It may be determined that the stop of the fuel supply should be prohibited when the set charge allowable power is equal to or higher than a predetermined limit value as the charge power, and the increase restriction setting means is configured to determine the temperature of the catalyst. When the temperature is equal to or higher than the predetermined temperature, one of the increase restrictions may be set as the increase restriction for execution based on the charge allowable power or the determination result of the catalyst high temperature history determination means.

  The hybrid vehicle according to the present invention may further include catalyst temperature acquisition means for detecting or estimating the temperature of the catalyst, and the catalyst high temperature history determination means is configured such that the detected or estimated temperature of the catalyst is the first. It may be determined that the temperature of the catalyst has entered the high temperature range when the temperature is equal to or higher than the temperature of the first, and the release condition is satisfied because the detected or estimated temperature of the catalyst is the first temperature. It may be when the temperature becomes lower than the second temperature lower than the above temperature. As described above, an increase restriction that tends to increase the fuel supply amount from the time when the temperature of the catalyst becomes equal to or higher than the first temperature to a temperature lower than the second temperature that is lower than the first temperature can be set. For example, the fuel supply was resumed even if the temperature of the catalyst entered the high temperature range that might cause the deterioration of the catalyst when the fuel supply to the internal combustion engine was stopped due to the fuel supply to the internal combustion engine being stopped. Sometimes, it becomes possible to supply a large amount of fuel to the internal combustion engine to suppress an increase in the temperature of the exhaust gas purifying catalyst or to lower the temperature of the catalyst. Therefore, even if the fuel supply is stopped again in a relatively short time after the fuel supply is temporarily stopped, that is, even if the frequency of stopping the fuel supply is increased, the deterioration of the exhaust gas purification catalyst is improved. It becomes possible to suppress.

  Furthermore, in the hybrid vehicle according to the present invention, the fuel supply stop determination means is configured so that the acquired temperature of the catalyst is equal to or higher than the second temperature, and the set allowable charging power is a predetermined limit value as charging power. When the above is true, it may be determined that the stop of the fuel supply should be prohibited, and the increase restriction setting means is configured to allow the charge allowable power when the temperature of the catalyst is equal to or higher than the second temperature. Alternatively, any increase restriction may be set as an execution increase restriction based on the determination result of the catalyst high temperature history determination means.

  In the hybrid vehicle according to the present invention, the power / power input / output means is connected to the first axle, the output shaft of the internal combustion engine, and a rotatable third shaft, and any two of these three shafts. And a three-axis power input / output means for inputting / outputting power determined based on power input / output to / from the remaining shaft, and a generator capable of inputting / outputting power to / from the third shaft. .

Other hybrid vehicles according to the present invention are:
An internal combustion engine;
Purification means including a catalyst for purifying exhaust gas discharged from the internal combustion engine;
Power power input / output means connected to the first axle as one of the axles and the output shaft of the internal combustion engine and capable of inputting / outputting power to / from the first axle and the output shaft with input / output of power and power When,
An electric motor capable of inputting / outputting power to / from a second axle that is either the first axle or an axle different from the first axle;
Power storage means capable of exchanging power between the power drive input / output means and the electric motor;
Charge allowable power setting means for setting charge allowable power that is power allowed for charging of the power storage means based on the state of the power storage means;
Fuel supply stop determination means for determining whether or not to stop the fuel supply to the internal combustion engine based on the set allowable charge power;
A plurality of drivings that define driving force setting constraints for setting a required driving force required for traveling and driving point constraints for setting an operating point of the internal combustion engine corresponding to the required driving force in different modes. An operation condition setting means for setting any one of the conditions as an operation condition for execution;
Vehicle information acquisition means for acquiring vehicle information related to at least one of a traveling road surface, a relationship with a preceding vehicle, and a traveling environment;
Determining means for determining a possibility that a predetermined driving condition having a driving force setting constraint having a relatively small lower limit of a power range is set as the execution driving condition based on the acquired vehicle information;
One of the increase constraints based on the set charge allowable power is selected from among a plurality of increase constraints that respectively define an increase in the amount of fuel supplied to the internal combustion engine for adjusting the temperature of the catalyst. On the other hand, when it is determined that the predetermined operation condition is likely to be set as the execution operation condition, the predetermined amount of fuel supply tends to be increased as the execution increase restriction. An increase restriction setting means for setting an increase restriction;
Driving force / operating point setting means for setting the required driving force and the target operating point of the internal combustion engine based on the set operating condition for execution;
The internal combustion engine is operated at the set target operation point with the increase in the fuel supply amount in accordance with the set execution increase restriction according to the determination result by the fuel supply stop determination means, and Control means for controlling the internal combustion engine, the electric power drive input / output means and the electric motor so that a driving force based on the set required driving force is output;
Is provided.

  In this hybrid vehicle, a plurality of increase restrictions that respectively define an increase in the amount of fuel supplied to the internal combustion engine for adjusting the temperature of the catalyst based on the allowable charge power set as the allowable power for charging the power storage means One of the increase constraints is set as the execution increase constraint, but there is a possibility that a predetermined operation condition having a driving force setting constraint with a relatively lower lower limit of the power range is set as the execution operation condition. When it is high, a predetermined increase restriction having a tendency to increase the fuel supply amount is set as the execution increase restriction. Then, in accordance with the determination result of whether or not to stop the fuel supply based on the allowable charging power, the internal combustion engine is operated at the target operation point set with the increase in the fuel supply amount according to the set execution increase constraint. As the engine is operated, the internal combustion engine, the power power input / output means, and the electric motor are controlled so that a driving force based on the required driving force required for traveling is output. That is, when a predetermined operating condition having a driving force setting constraint with a relatively small lower limit of the power range is set as an operating condition for execution, the required driving force and the purification catalyst are set even though the purifying catalyst is in a relatively high temperature state. Therefore, there is a high possibility that the prohibition of stopping the fuel supply is canceled based on the allowable charging power. Therefore, when there is a high possibility that the predetermined operation condition is set as the execution operation condition, if a predetermined increase restriction that tends to increase the fuel supply amount is set as the execution increase restriction, the internal combustion engine is set in advance. It is possible to supply more fuel to the engine to suppress the temperature increase of the exhaust gas purification catalyst or to lower the temperature of the exhaust gas purification catalyst. Thereby, even if the prohibition of the stop of the fuel supply is canceled based on the charge allowable power within a relatively short time after the predetermined operation condition is set as the operation condition for execution, even if the fuel supply is stopped, Deterioration of the exhaust gas purification catalyst can be satisfactorily suppressed.

A control method for a hybrid vehicle according to the present invention includes an internal combustion engine, a purification means including a catalyst for purifying exhaust gas discharged from the internal combustion engine, a first axle as one of the axles, and an output shaft of the internal combustion engine. And an electric power / power input / output means capable of inputting / outputting power to / from the first axle and the output shaft with input / output of electric power and power, and the first axle or an axle different from the first axle. A control method for a hybrid vehicle, comprising: an electric motor capable of inputting / outputting power to / from a second axle, and an electric power driving input / output means and an electric storage means capable of exchanging electric power between the electric motor,
(A) setting a charge allowable power set as a power allowed for charging the power storage means based on a state of the power storage means;
(B) determining whether to prohibit the stop of fuel supply to the internal combustion engine based on the set allowable charging power;
(D) Any increase based on the charge allowable power set in step (a) from among a plurality of increase restrictions respectively defining an increase in the fuel supply amount to the internal combustion engine for adjusting the temperature of the catalyst When it is determined that the temperature of the catalyst has entered a predetermined high temperature range that may cause deterioration of the catalyst when the fuel supply to the internal combustion engine is stopped, the constraint is set as an execution increase constraint. Setting a predetermined increase constraint having a tendency to increase the fuel supply amount as the execution increase constraint until
(E) According to the determination result in step (b), the internal combustion engine is operated with the increase in the fuel supply amount in accordance with the set fuel increase restriction, and the driving force required for traveling is output. Controlling the internal combustion engine, the power drive input / output means and the electric motor,
Is included.

  As in this method, when a history that the temperature of the catalyst of the purification means has entered a predetermined high temperature range is recognized, the fuel supply amount tends to be increased as an execution increase constraint until a predetermined release condition is satisfied. If the predetermined increase restriction is set, more fuel is supplied to the internal combustion engine in accordance with the predetermined increase restriction to suppress an increase in the temperature of the exhaust gas purification catalyst or to lower the catalyst temperature. Therefore, the prohibition of the stop of the fuel supply is subsequently released based on the relationship with the charge allowable power, and the deterioration of the catalyst can be satisfactorily suppressed when the fuel supply is stopped.

Another hybrid vehicle control method according to the present invention includes an internal combustion engine, a purification means including a catalyst for purifying exhaust gas discharged from the internal combustion engine, a first axle as one of the axles, and the internal combustion engine. The first axle or the first axle is different from the first axle or the electric power input / output means connected to the output shaft and capable of inputting / outputting power to / from the first axle and the output shaft with input / output of electric power and power. An electric motor capable of inputting / outputting power to / from a second axle which is one of the axles, an electric storage unit capable of exchanging electric power between the electric power input / output means and the electric motor, and a required driving force required for traveling. Any one of a plurality of operating conditions that define a driving force setting constraint for setting and an operating point constraint for setting the operating point of the internal combustion engine corresponding to the required driving force in different modes. Execution A hybrid vehicle control method comprising: an execution driving condition setting unit that is set as a driving condition; and a vehicle information acquisition unit that acquires vehicle information related to at least one of a traveling road surface, a relationship with a preceding vehicle, and a traveling environment. And
(A) setting a charge allowable power set as a power allowed for charging the power storage means based on a state of the power storage means;
(B) determining whether to prohibit the stop of fuel supply to the internal combustion engine based on the set allowable charging power;
(C) Any increase based on the charge allowable power set in step (a) from among a plurality of increase restrictions that respectively define an increase in fuel supply to the internal combustion engine for adjusting the temperature of the catalyst. While a constraint is set as an execution increase constraint, there is a high possibility that a predetermined operating condition having a driving force setting constraint with a relatively low lower limit of the power range is set as the execution driving condition based on the vehicle information A predetermined increase restriction having a tendency to increase the fuel supply amount as the execution increase restriction,
(D) The internal combustion engine at the operation point based on the operation point constraint in the set operation condition for execution with the increase in the fuel supply amount according to the set increase constraint according to the determination result in step (b) Controlling the internal combustion engine, the power power input / output means, and the electric motor so that a required driving force based on a driving force constraint in the set execution operating condition is output while the engine is operated;
Is included.

  As in this method, when there is a high possibility that a predetermined operating condition having a driving force setting constraint whose lower limit of the power range is relatively small is set as the operating condition for execution, the fuel supply amount is set as the execution increase constraint. By setting a predetermined increase restriction with a tendency to increase more, it is possible to supply more fuel to the internal combustion engine in advance to suppress the temperature increase of the exhaust gas purification catalyst or to lower the temperature of the exhaust gas purification catalyst. . Thereby, even if the prohibition of the stop of the fuel supply is canceled based on the charge allowable power within a relatively short time after the predetermined operation condition is set as the operation condition for execution, even if the fuel supply is stopped, Deterioration of the exhaust gas purification catalyst can be satisfactorily suppressed.

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

The engine 22 is configured as an internal combustion engine that can output power using a hydrocarbon fuel such as gasoline or light oil. As can be seen from FIG. 2, the engine 22 takes in the air cleaned by the air cleaner 122 into the intake port via the throttle valve 124 and injects gasoline from the fuel injection valve 126 to mix intake air and gasoline. The air-fuel mixture is sucked into the combustion chamber through the intake valve 128 and explosively burned by an electric spark from the spark plug 130, 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 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), and a co-catalyst such as ceria (CeO ₂ ). . 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 configured as described above 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 a processing program, a RAM 24c that temporarily stores data, and an input / output (not shown) And a communication port. For example, the engine ECU 24 includes a cylinder position that is a crank position from a crank position sensor 140 that detects the rotational position of the crankshaft 26, a cooling water temperature from a water temperature sensor 142 that detects a temperature of cooling water in the engine 22, and a pressure in the combustion chamber. In-cylinder pressure from a pressure sensor 143 that detects internal pressure, a cam position from a cam position sensor 144 that detects the rotational position of an intake valve 128 that performs intake and exhaust to a combustion chamber, and a camshaft that opens and closes an exhaust valve, and a throttle valve 124 The throttle port position sensor 146 for detecting the position of the engine, the intake air amount GA from the air flow meter 148 provided in the intake pipe, the intake air temperature from the temperature sensor 149 provided in the intake pipe, and the like are input ports. Is entered through . As shown in FIG. 2, when the temperature sensor 135 is provided in the purification device 134, the catalyst bed temperature Tcat or the like from the temperature sensor 135 may be input to the engine ECU 24. 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, and controls the operation of the engine 22 by a control signal from the hybrid electronic control unit 70, and the data regarding the operation state of the engine 22 as necessary. Output to.

  The power distribution and integration mechanism 30 includes an external gear sun gear 31, an internal gear ring gear 32 arranged concentrically with the sun gear 31, a plurality of pinion gears 33 that mesh with the sun gear 31 and mesh with the ring gear 32, A planetary gear mechanism is provided that includes a carrier 34 that holds a plurality of pinion gears 33 so as to rotate and revolve, and that performs differential action using the sun gear 31, the ring gear 32, and the carrier 34 as rotational elements. The crankshaft 26 of the engine 22 is connected to the carrier 34, the motor MG1 is connected to the sun gear 31, and the reduction gear 35 is connected to the ring gear 32 via the ring gear shaft 32a. The power distribution and integration mechanism 30 includes the motor MG1. When functioning as a generator, power from the engine 22 input from the carrier 34 is distributed according to the gear ratio between the sun gear 31 side and the ring gear 32 side, and when the motor MG1 functions as an electric motor, the engine input from the carrier 34 The power from 22 and the power from the motor MG1 input from the sun gear 31 are integrated and output to the ring gear 32 side. The power output to the ring gear 32 is finally output from the ring gear shaft 32a to the drive wheels 63a and 63b of the vehicle via the gear mechanism 60 and the differential gear 62.

  Both the motor MG1 and the motor MG2 are configured as well-known synchronous generator motors that can operate as a generator and operate as an electric motor, and exchange power with the battery 50 via inverters 41 and 42. The power line 54 connecting the inverters 41 and 42 and the battery 50 is configured as a positive bus and a negative bus shared by the inverters 41 and 42, and the power generated by any one of the motors MG 1 and MG 2 It can be consumed by a motor. Therefore, the battery 50 is charged / discharged by electric power generated from one of the motors MG1 and MG2 or insufficient electric power. If the balance of electric power is balanced by the motors MG1 and MG2, the battery 50 is not charged / discharged. The motors MG1 and MG2 are both driven and controlled by a motor electronic control unit (hereinafter referred to as “motor ECU”) 40. The motor ECU 40 detects signals necessary for driving and controlling the motors MG1 and MG2, such as signals from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and current sensors (not shown). The phase current applied to the motors MG1 and MG2 is input, and a switching control signal to the inverters 41 and 42 is output from the motor ECU 40. The motor ECU 40 is in communication with the hybrid ECU 70, controls the driving of the motors MG1, MG2 by a control signal from the hybrid ECU 70, and outputs data related to the operating state of the motors MG1, MG2 to the hybrid ECU 70 as necessary.

  The battery 50 is managed by a battery electronic control unit (hereinafter referred to as “battery ECU”) 52. The battery ECU 52 receives signals necessary for managing the battery 50, for example, a voltage between terminals from a voltage sensor (not shown) installed between the terminals of the battery 50, and a power line 54 connected to the output terminal of the battery 50. The charging / discharging current from the attached current sensor (not shown), the battery temperature Tb from the temperature sensor 51 attached to the battery 50, and the like are input, and the battery ECU 52 communicates data regarding the state of the battery 50 as necessary. Is output to the hybrid ECU 70 and the engine ECU 24. The battery ECU 52 also calculates the remaining capacity (SOC) based on the integrated value of the charge / discharge current detected by the current sensor in order to manage the battery 50.

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

  In the hybrid vehicle 20 of this embodiment, the shift position SP of the shift lever 81 includes a parking position used during parking, a reverse position for reverse travel, a neutral position for neutral travel, and a normal drive position for forward travel (hereinafter, “ In addition to “D position”, a brake position (hereinafter referred to as “B position”) that is selected mainly when the vehicle is traveling on a downhill at a relatively high speed is prepared. Driving that defines driving force setting restrictions for setting the required driving force required for traveling and driving point restrictions for setting the operating point of the engine 22 corresponding to the required driving force at the D position and the B position. Conditions are associated. That is, when the D position is selected as the shift position SP, the required torque Tr * as the required driving force according to the amount of depression of the accelerator pedal 83 by the driver within the power range as the driving force restriction corresponding to the D position is obtained. The target rotational speed Ne * and the target torque Te *, which are target operating points of the engine 22 corresponding to the required torque Tr *, are set in accordance with the operating point restrictions determined so that the engine 22 is efficiently operated. The Further, when the B position is selected as the shift position SP, the required torque Tr *, the target rotational speed Ne *, and the target torque Te * are set according to the driving force constraint and the operating point constraint corresponding to the B position. In this embodiment, the driving force constraint and the driving point constraint corresponding to the B position are basically the same as those corresponding to the D position, but the driving force constraint in the driving condition corresponding to the B position is the D position. The lower limit of the power range is set smaller (larger as braking force) than the driving force constraint under the corresponding driving conditions, and when the B position is selected, when the accelerator is off under the predetermined condition, compared to when the D position is selected A large braking force can be obtained.

  The hybrid vehicle 20 of the present embodiment configured as described above should output to the ring gear shaft 32a as the drive shaft based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal 83 by the driver. The engine 22, the motor MG <b> 1, and the motor MG <b> 2 are controlled to calculate the required torque Tr * and output the power corresponding to the required torque Tr * to the ring gear shaft 32 a. 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, a torque conversion operation mode for driving and controlling the motor MG1 and the motor MG2 so that the torque is converted by the motor MG1 and the motor MG2 and output to the ring gear shaft 32a, and the required power and the power required for charging and discharging the battery 50 The engine 22 is operated and controlled so that 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 motor MG2 with torque conversion, the required power is ring gear A charge / discharge operation mode for driving and controlling the motor MG1 and the motor MG2 to be output to the shaft 32a, and a motor for controlling the operation so as to output the power corresponding to the required power from the motor MG2 to the ring gear shaft 32a. There are operation modes.

  Next, the operation of the hybrid vehicle 20 of the present embodiment, in particular, the operation of the hybrid vehicle 20 in the accelerator-on state accompanied by the operation of the engine 22 will be described. FIG. 3 is a flowchart showing an example of a drive control routine executed by the hybrid ECU 70 when the accelerator is on. This routine is repeatedly executed at predetermined time intervals (for example, every several milliseconds) when the accelerator operation state is in the accelerator on state.

  When the drive control routine of FIG. 3 is started, first, the CPU 72 of the hybrid ECU 70 first determines the accelerator opening Acc from the accelerator pedal position sensor 84, the vehicle speed V from the vehicle speed sensor 88, and the rotational speeds Nm1, Nm2 of the motors MG1, MG2. Then, input processing of data necessary for control such as charge / discharge required power Pb * to be charged / discharged by the battery 50 and input / output restrictions Win and Wout of the battery 50 is executed (step S100). In this case, the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 are input from the motor ECU 40 by communication from those calculated based on the rotational positions of the rotors of the motors MG1 and MG2 detected by the rotational position detection sensors 43 and 44. To do. The charge / discharge required power Pb * is input from the battery ECU 52 by communication. Input / output restrictions Win and Wout of the battery 50 are input from the battery ECU 52 by communication from the battery temperature Tb of the battery 50 detected by the temperature sensor 51 and the remaining capacity (SOC) of the battery 50. It was. The input / output limits Win and Wout of the battery 50 are set to basic values of the input / output limits Win and Wout based on the battery temperature Tb, and are input to the output limiting correction coefficient based on the remaining capacity (SOC) of the battery 50. It is possible to set a correction coefficient for restriction and multiply the basic value of the set input / output restrictions Win and Wout by the correction coefficient. FIG. 4 shows an example of the relationship between the battery temperature Tb and the input / output limits Win, Wout, and FIG. 5 shows an example of the relationship between the remaining capacity (SOC) of the battery 50 and the correction coefficients of the input / output limits Win, Wout.

  After the data input process in step S100, the required torque Tr * to be output to the ring gear shaft 32a as the drive shaft connected to the drive wheels 63a, 63b based on the input accelerator opening Acc and the vehicle speed V and the engine 22 are requested. The required power Pe * is set (step S110). In this embodiment, the relationship between the accelerator opening Acc and 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, and when the accelerator opening Acc and the vehicle speed V are given, the map is displayed. Therefore, the required torque Tr * corresponding to these is derived and set. FIG. 6 shows an example of the required torque setting map. Further, in the present embodiment, a value obtained by multiplying the set required torque Tr * by the rotation speed Nr (= Nm2 / Gr) of the ring gear shaft 32a and the charge / discharge required power Pb * to be charged / discharged by the battery 50 and the loss Loss The required power Pe * for the engine 22 is set as the sum. Subsequently, the target rotational speed Ne * and the target torque Te * of the engine 22 are set based on the required power Pe * for the engine 22 set in step S110 (step S120). In this embodiment, the target rotational speed Ne * and the target torque Te * are set as target operating points of the engine 22 based on the operation line for efficiently operating the engine 22 and the required power Pe *. FIG. 7 illustrates an example of an operation line of the engine 22 and a correlation curve between the target rotational speed Ne * and the target torque Te *. As shown in the figure, the target rotational speed Ne * and the target torque Te * can be obtained from the intersection of the operation line and the correlation curve indicating that the required power Pe * (Ne * × Te *) is constant.

  Further, based on the target rotational speed Ne * set in step S120, the rotational speed Nr (= Nm2 / Gr) of the ring gear shaft 32a, and the gear ratio ρ of the power distribution and integration mechanism 30, the calculation using the following equation (1) is performed. The target rotational speed Nm1 * of the motor MG1 is obtained, and the torque command Tm1 * of the motor MG1 is set by calculation using the following equation (2) based on the obtained target rotational speed Nm1 * and the current rotational speed Nm1 ( Step S130). Expression (1) is a dynamic relational expression related to the rotating elements of the power distribution and integration mechanism 30. FIG. 8 is a collinear diagram showing a dynamic relationship between the rotational speed and torque of each rotary element in the power distribution and integration mechanism 30. In the figure, the left S-axis indicates the rotational speed of the sun gear 31 that matches the rotational speed Nm1 of the motor MG1, the C-axis indicates the rotational speed of the carrier 34 that matches the rotational speed Ne of the engine 22, and the R-axis indicates the motor MG2. The rotational speed Nr of the ring gear 32 obtained by dividing the rotational speed Nm2 by the gear ratio Gr of the reduction gear 35 is shown. Further, two thick arrows on the R axis indicate that the torque acting on the ring gear shaft 32a by this torque output when the torque Tm1 is output from the motor MG1 and the torque Tm2 output from the motor MG2 via the reduction gear 35. The torque acting on the ring gear shaft 32a is shown. Equation (1) for obtaining the target rotational speed Nm1 * of the motor MG1 can be easily derived by using the rotational speed relationship in this alignment chart. In the equation (1), ρ is the gear ratio of the power distribution and integration mechanism 30 (the number of teeth of the sun gear 31 / the number of teeth of the ring gear 32). In the equation (2), “k1” in the second term on the right side is The gain of the proportional term, and “k2” in the third term on the right side is the gain of the integral term.

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

  When the torque command Tm1 * is set, the current motor MG1 is added to the output limit Wout or the input limit Win of the battery 50 input in step S100 according to the following equations (3) and (4), and the set torque command Tm1 * of the motor MG1. The torque limits Tmax and Tmin as upper and lower limits of the torque that may be output from the motor MG2 are calculated by dividing the deviation from the power consumption of the motor MG1 obtained by multiplying the rotation speed Nm1 by the rotation speed Nm2 of the motor MG2. (Step S140). Further, a temporary motor as a torque to be output from the motor MG2 according to the following equation (5) using the required torque Tr *, the torque command Tm1 *, the gear ratio ρ of the power distribution and integration mechanism 30 and the gear ratio Gr of the reduction gear 35. Torque Tm2tmp is calculated (step S150), and torque command Tm2 * of motor MG2 is set by limiting calculated temporary motor torque Tm2tmp with torque limits Tmax and Tmin (step S160). By setting the torque command Tm2 * of the motor MG2 in this way, the required torque Tr * output to the ring gear shaft 32a is basically set as a torque that is limited within the range of the input / output limits Win and Wout of the battery 50. be able to. Equation (5) can be easily derived from the alignment chart of FIG. When 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 transferred to the engine ECU 24 and the motor. Torque commands Tm1 * and Tm2 * of MG1 and MG2 are transmitted to motor ECU 40, respectively (step S170). The engine ECU 24 having received the target rotational speed Ne * and the target torque Te *, based on the received target rotational speed Ne * and the target torque Te *, stores a fuel injection amount setting map (not shown) and a throttle stored in the ROM 24b. A fuel injection amount for the engine 22, a position of the throttle valve 124 (throttle opening), and the like are determined using an opening setting map and the like, and an ignition timing setting map (not shown) stored in the ROM 24b is used. The ignition timing is determined, and control for obtaining the target rotational speed Ne * and the target torque Te * is executed. The motor ECU 40 that has received the torque commands Tm1 * and Tm2 * switches the switching elements of the inverters 41 and 42 so that the motor MG1 is driven according to the torque command Tm1 * and the motor MG2 is driven according to the torque command Tm2 *. Take control.

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

  Here, when the vehicle speed V is higher than the relatively high predetermined vehicle speed through the accelerator-on state accompanied by the operation of the engine 22 as described above, the depression of the accelerator pedal 83 is released by the driver and a deceleration request is made. In this case, the fuel injection to the engine 22 is basically stopped, and the required torque when the accelerator opening degree determined from the required torque setting map of FIG. 6 is 0% (accelerator off) while mainly using the engine brake ( The engine 22 and the motors MG1 and MG2 are controlled so that (braking torque) Tr * is obtained. However, if fuel injection to the engine 22 is stopped when the exhaust gas purification catalyst of the purification device 134 is in a high temperature state, only the air that has passed through the combustion chamber is supplied to the purification device 134, and the exhaust gas purification catalyst is in a lean atmosphere. When exposed to the catalyst, the oxidation catalyst or the reduction catalyst grows and the surface area decreases, which may cause deterioration of the exhaust gas purification catalyst (decrease in purification function). For this reason, depending on the temperature of the exhaust gas purifying catalyst (catalyst bed temperature Tcat), stop of fuel injection to the engine 22 (hereinafter referred to as “fuel cut”) is prohibited, and the fuel injection amount to the engine 22 is appropriately increased and corrected. It is preferable to adjust the catalyst bed temperature Tcat of the exhaust gas purification catalyst. On the other hand, when a deceleration request based on accelerator-off is made in a state where fuel cut is prohibited, the hybrid vehicle 20 controls the engine 22 and the motors MG1 and MG2 to perform fuel injection to the engine 22 according to predetermined conditions. While continuing ignition (firing) and adjusting the opening of the throttle valve 124, the engine 22 is output from the engine 22 to the motor MG2 while gradually reducing the engine 22 to a predetermined engine speed (for example, engine speed during idling). The required torque (braking torque) Tr * when the accelerator opening determined from the required torque setting map of FIG. In this case, the motor MG2 generates electric power as the braking force is generated, and the regenerative electric power is stored in the battery 50. However, the input limit as charging allowable electric power that is allowable electric power for charging the battery 50 is used. Depending on the value of Win, such regeneration by the motor MG2 may be limited. For this reason, in the hybrid vehicle 20 of the present embodiment, the fuel injection amount for the engine 22 is increased and corrected while considering both the catalyst bed temperature Tcat of the exhaust gas purification catalyst of the purification device 134 and the input limit Win of the battery 50. A catalyst deterioration suppression determination routine described below is executed so that deterioration of the exhaust gas purification catalyst can be suppressed.

  FIG. 9 is a flowchart illustrating an example of a catalyst deterioration suppression determination routine. This routine is repeatedly executed by the engine ECU 24, for example, every several mSec. When the catalyst deterioration suppression determination routine of FIG. 9 is started, the CPU 24a of the engine ECU 24 determines the catalyst bed temperature Tcat, the input limit Win of the battery 50, the value of the FC flag Ffc indicating whether or not the fuel cut is being executed. Data input processing necessary for the process is executed (step S200). In this embodiment, the catalyst bed temperature Tcat is estimated from the rotational speed Ne of the engine 22, the intake air amount, an increase in the fuel injection amount described later, and the like and stored in the RAM 24c. When the temperature sensor 135 (see FIG. 2) is provided in the purifier 134, the catalyst bed temperature Tcat detected by the temperature sensor 135 may be input. Further, the input limit Win of the battery 50 is input from the battery ECU 52 by communication. Further, the FC flag Ffc is set to the value 0 when the fuel cut is not executed in the engine ECU 24, and is set to the value 1 when the fuel cut is executed. Then, after the data input process in step S200, it is determined whether or not the input catalyst bed temperature Tcat is equal to or higher than a predetermined reference temperature Tref (step S210). The reference temperature Tref is determined based on a temperature that is less likely to deteriorate when the exhaust gas purification catalyst is exposed to a lean atmosphere due to fuel cut, and is set to, for example, 800 ° C. in this embodiment. When the catalyst bed temperature Tcat is lower than the reference temperature Tref, the fuel cut prohibition flag Fc is set to a value 0 assuming that there is little possibility that the exhaust gas purification catalyst will deteriorate even if fuel cut is permitted (step S330).

  When it is determined that the catalyst bed temperature Tcat is equal to or higher than the reference temperature Tref and the exhaust gas purification catalyst is in a high temperature state to some extent, it is determined whether or not the input limit Win input in step S200 is equal to or lower than the temporary limit value Win0. (Step S220). The temporary limit value Win0 as a threshold value related to the input limit Win of the battery 50 is the input of the battery 50 when the torque (braking torque) required when the accelerator is off is covered by the regenerative braking force by the motor MG2 without cutting the fuel. The limit value Win is defined as a value smaller than the limit value (minimum value as charging power) Win1, that is, a value as charging power that is large (with a margin), and is obtained through experiments and analysis in advance together with the limit value Win1. Value. Since the input limit Win is originally a negative value, the input limit Win is equal to or less than the temporary limit value Win0, that is, the input limit Win exceeds the temporary limit value Win0 as charging power. This means that a relatively large value (a value with a large absolute value) can be set. If the input limit Win is less than or equal to the temporary limit value Win0, it is determined whether or not a flag F described later is a value 0 (step S230). If the flag F is a value 0, the FC flag Ffc is further set to a value. It is determined whether or not it is 0, that is, whether or not a fuel cut is being executed (S240). If the fuel cut is not executed and the FC flag Ffc is 0, an increase coefficient for increasing the fuel injection amount for the engine 22 set using the fuel injection amount setting map is set. As a map for this, the first OT increase coefficient setting map illustrated in FIG. 10A is set by reading from the ROM 24b, and the opening of the throttle valve 124 set using the above-described throttle opening setting map is corrected. A first TA correction map (not shown) is set by reading from the ROM 24b (step S250), and a fuel cut prohibition flag Fc that is set to 0 when permitting a fuel cut is set to prohibit the fuel cut. The value is set to 1 (step S260), and this routine is temporarily terminated.

  Thus, when the first OT increase coefficient setting map and the first TA correction map are set as the maps for setting the increase coefficient in step S250, the fuel cut is prohibited in step S260, and the engine ECU 24 starts from the hybrid ECU 70. When setting the fuel injection amount for the engine 22 and the opening degree of the throttle valve 124 based on the target rotational speed Ne * and the target torque Te *, which are the command values of the engine, and the predetermined restrictions when the fuel cut is prohibited, from these maps The fuel injection amount is increased and the throttle opening is corrected in accordance with the derived fuel injection amount increase coefficient and the throttle opening correction coefficient. As illustrated in FIG. 10A, the first OT increase coefficient setting map defines an increase coefficient according to the target rotational speed Ne * of the engine 22 and the volumetric efficiency KL related to the intake air amount. Basically, it is created so as to take a larger value as the increase coefficient as the target rotational speed Ne * and the volumetric efficiency KL increase. In this embodiment, the first OT increase coefficient setting map defines an increase coefficient of the fuel injection amount for suppressing an increase in the catalyst bed temperature Tcat according to the target rotational speed Ne * of the engine 22 and the volumetric efficiency KL. Has been created. As a result, when the first OT increase coefficient setting map is set, the amount of increase in the fuel injection amount is relatively small, so that the fuel consumption required for temperature adjustment to suppress the deterioration of the exhaust gas purification catalyst is reduced. Can do. The first TA correction map (not shown) cancels the deviation between the target torque Te * resulting from increasing the fuel injection amount based on the first OT increase coefficient setting map and the torque actually output from the engine 22. As described above, the throttle opening correction coefficient is created in advance in accordance with the target rotational speed Ne * and the target torque Te *. That is, the correction coefficient for the throttle opening in the first TA correction map is set, for example, so as to make the throttle opening smaller than normal in an operating region where the torque increases when the fuel injection amount is increased. The operating range in which the torque sometimes decreases is determined to make the throttle opening smaller than usual. Thereby, when the fuel injection amount increase correction is executed using the first OT increase coefficient setting map, the shock due to the deviation between the target torque Te * and the torque actually output from the engine 22 is reduced. be able to.

  On the other hand, if it is determined in step S220 that the input limit Win exceeds the temporary limit value Win0, it is determined whether or not the input limit Win is equal to or less than the limit value Win1 (step S270). ). When the input limit Win is equal to or less than the limit value Win1, that is, when the charging power is equal to or greater than the limit value Win1, the increase for correcting the increase in the fuel injection amount for the engine 22 set using the fuel injection amount setting map described above. As a map for setting the coefficient, the second OT increase coefficient setting map illustrated in FIG. 10B having a tendency to increase the fuel injection amount as compared with the first OT increase coefficient setting map is read from the ROM 24b and set. At the same time, a second TA correction map (not shown) for correcting the opening of the throttle valve 124 set using the above-described throttle opening setting map is read from the ROM 24b and set (step S280), and further fuel cut The prohibition flag Fc is set to a value 1 (step S260), and this routine is terminated once. If it is determined in step S270 that the input limit Win exceeds the limit value Win1, the fuel cut prohibition flag Fc is set to 0 to cancel the fuel cut prohibition according to the state of the battery 50. (Step S330).

  Thus, even when the second OT increase coefficient setting map or the second TA correction map is set as the map for setting the increase coefficient in step S280, the fuel cut is prohibited in step S260, and the engine ECU 24 is controlled by the hybrid ECU 70. When the fuel injection amount for the engine 22 and the opening degree of the throttle valve 124 are set based on the target rotational speed Ne *, the target torque Te *, etc., the fuel injection amount increase coefficient derived from these maps and the throttle The fuel injection amount is increased or the throttle opening is corrected according to the opening correction coefficient. The second OT increase coefficient setting map also defines an increase coefficient in accordance with the target rotational speed Ne * of the engine 22 and the volumetric efficiency KL related to the intake air amount, as illustrated in FIG. 10B. Basically, it is created so as to take a larger value as the increase coefficient as the target rotational speed Ne * and the volumetric efficiency KL increase. In the present embodiment, the second OT increase coefficient setting map defines an increase coefficient of the fuel injection amount for decreasing the catalyst bed temperature Tcat according to the target rotational speed Ne * of the engine 22 and the volumetric efficiency KL. Has been created. That is, the second OT increase coefficient setting map is created so as to take a larger increase coefficient while the target rotational speed Ne * and the volumetric efficiency KL are relatively lower than the first OT increase coefficient setting map. When the 2OT increase coefficient setting map is set, the fuel injection amount increases basically as the vehicle speed V is higher than when the first OT increase coefficient setting map is set. Further, the second TA correction map (not shown) cancels the deviation between the target torque Te * resulting from the increase in the fuel injection amount based on the second OT increase coefficient setting map and the torque actually output from the engine 22. As described above, the throttle opening correction coefficient is created in advance in accordance with the target rotational speed Ne * and the target torque Te *. As a result, even when the fuel injection amount increase correction is executed using the second OT increase coefficient setting map, the shock caused by the deviation between the target torque Te * and the torque actually output from the engine 22 is reduced. can do.

  Thus, in the hybrid vehicle 20 of the present embodiment, the first OT increase coefficient setting map for determining the increase amount of the fuel injection amount in accordance with the comparison result between the input limit Win of the battery 50 and the temporary limit value Win0. And the second OT increase coefficient setting map are selected, and the temporary limit value Win0 as a threshold is as follows on the assumption that the fuel injection amount is increased using the second OT increase coefficient setting map. Determined. That is, the temporary limit value Win0 is basically set to a target temperature (for example, 920 ° C.) when the catalyst bed temperature Tcat is suppressed to an extent that the deterioration of the exhaust gas purification catalyst is suppressed according to the following equation (6). When they match, the fuel injection amount is increased by using the second OT increase coefficient setting map, and the catalyst bed temperature Tcat is less likely to deteriorate even if the exhaust gas purification catalyst is exposed to a lean atmosphere (for example, less than 800 ° C.) The minimum time T required for the temperature to be reduced to (temperature) is obtained by experiment and analysis, and the value obtained by multiplying the obtained minimum time T by the maximum variation ΔWin per unit time of the input limit Win and the limit value Win1 are added. Determined by.

  Win0 = Win1 + ΔWin · T (6)

  Incidentally, in the hybrid vehicle 20 of this embodiment, as can be seen from FIG. 6, the B position selected when the vehicle is traveling on a downhill at a relatively high speed, for example, is the D position set during normal traveling. Compared to the shift position SP, the required braking force based on the accelerator-off is set larger. That is, when the B position is selected as the shift position SP, the required torque Tr * set when the accelerator opening degree Acc is 0% (accelerator off) is smaller than when the D position is selected, that is, as a braking force. growing. Therefore, when the B position is selected, the torque output from the engine 22 to the motor MG2 is canceled while continuing fuel injection to the engine 22 when a deceleration request based on accelerator off is made in a state where fuel cut is prohibited. At the same time, if the required torque (braking torque) Tr * when the accelerator opening is 0% is output, the regenerative power by the motor MG2 becomes larger than when the D position is selected, so that the regenerative power may not be stored in the battery 50. Will increase. In such a case, the value of the input limit Win is set smaller as the charging power from the relationship with the remaining capacity (SOC) of the battery 50, so that the B position is selected compared to the D position selected. The input limit Win tends to become less than the limit value Win1 as the charging power, and there is a high possibility that the prohibition of fuel cut is released based on the input limit Win even though the exhaust gas purification catalyst is in a relatively high temperature state. Further, when the prohibition of fuel cut is canceled based on the input limit Win and the fuel cut is once executed, the exhaust gas purification catalyst is exposed to a lean atmosphere and heated up, and the catalyst bed temperature Tcat is increased. Then, when the fuel is cut again and exposed to a lean atmosphere, the temperature may rise to a temperature that may cause catalyst deterioration. Depending on the driver's request, the deceleration request due to the accelerator off at the B position and the acceleration request due to the accelerator on at the D position may be repeated frequently. There is a possibility that fuel cuts must be frequently performed even though the temperature is relatively high.

  For this reason, in the catalyst deterioration suppression determination routine of this embodiment, it is determined in step S220 that the input limit Win is equal to or less than the temporary limit value Win0, and in step S240, it is determined that the fuel cut is being performed. In other words, if the fuel cut is performed when the above-described first OT increase coefficient setting map is to be set, the catalyst temperature increase Tcat may cause deterioration of the exhaust gas purification catalyst when the fuel is cut. Is considered to have entered. If it is determined in step S240 that the fuel cut is being executed, the flag F is set to 1 (step S290), and a counter (not shown) is incremented (step S300). Further, it is determined whether or not the count value N of the counter is less than a predetermined threshold Nr (step S310). If the count value N is less than the threshold Nr, the second OT increase coefficient setting map and the second TA The correction map is read from the ROM 24b and set (step S280). Also, once the flag F is set to the value 1 in step S290, if it is determined in step S220 that the input limit Win is equal to or less than the temporary limit value Win0, the counter is incremented in step S300 after the determination in step S230. Until the count value N reaches the threshold value Nr, the second OT increase coefficient setting map and the second TA correction map are set in step S280. Thereby, in the hybrid vehicle 20 of the present embodiment, when the fuel cut is executed when the first OT increase coefficient setting map is to be set, the second OT increase is only performed until the count value of the counter reaches the threshold value Nr. A coefficient setting map and a second TA correction map are set, and the fuel injection amount can be increased and the throttle opening can be corrected according to these maps. If it is determined in step S310 that the count value N has reached the threshold value Nr, the count value N is reset (step S320), and then the first OT increase coefficient setting map and the first TA correction map are displayed. It is set (step S250). In the present embodiment, the threshold Nr used in step S310 is based on the second OT increase coefficient setting map and the second OT increase coefficient setting map, for example, for about 20 seconds after the fuel cut is performed based on the execution interval of the catalyst deterioration suppression determination routine. It is determined that a 2TA correction map is set.

  As described above, in the hybrid vehicle 20 of the present embodiment, basically, if the input limit Win as the charge allowable power set as the power allowed for charging the battery 50 is equal to or less than the temporary limit value Win0, If the 1OT increase coefficient setting map is set and the input limit Win exceeds the temporary limit value Win0 and is equal to or less than the limit value Win1, the fuel injection amount tends to increase more than the first OT increase coefficient setting map. The second OT increase coefficient setting map is set. Then, when the fuel cut is prohibited (including when the accelerator is on and when the fuel injection is continued) according to the determination result of whether or not to prohibit the fuel cut performed based on the input restriction Win, the first set value is set. Alternatively, the engine 22 and the motor are operated so that the engine 22 is operated with an increase in the fuel injection amount according to the second OT increase coefficient setting map and a driving force based on the required torque Tr * required for traveling is output. MG1 and MG2 are controlled. Further, when the detected or estimated catalyst bed temperature Tcat is equal to or higher than the reference temperature Tref and the input limit Win is equal to or lower than the temporary limit value Win0, the fuel cut is performed when the first OT increase coefficient setting map should be set. If it is executed, it is considered that the catalyst bed temperature Tcat has entered a predetermined high temperature range that may cause catalyst deterioration at the time of fuel cut. In this case, the fuel injection amount tends to be increased further for a predetermined time thereafter. A 2OT increase coefficient setting map is set. Thus, when the history that the temperature of the exhaust gas purifying catalyst has entered the high temperature range is recognized, a second OT increase coefficient setting map is set which tends to increase the fuel injection amount until the release condition is satisfied. If this is done, more fuel can be supplied to the engine 22 to lower the temperature of the exhaust gas purification catalyst, or at least the temperature increase of the exhaust gas purification catalyst can be suppressed. When the prohibition is lifted and the fuel cut is executed, it is possible to satisfactorily suppress the deterioration of the exhaust gas purification catalyst.

  That is, when the first OT increase coefficient setting map is to be set, the temperature of the exhaust gas purification catalyst is increased to some extent. Therefore, when a fuel cut is performed in such a case, the catalyst bed temperature Tcat becomes the exhaust gas during the fuel cut. It becomes easy to enter a high temperature range that may cause deterioration of the purification catalyst. Therefore, when the input limit Win is equal to or less than the temporary limit value Win0 and the fuel cut is performed when the first OT increase coefficient setting map is to be set, it is considered that the catalyst bed temperature Tcat has entered the high temperature range, By setting a second OT increase coefficient setting map that tends to increase the fuel injection amount until a predetermined time or more has elapsed since the fuel cut was executed, more fuel can be saved when fuel injection is resumed. It can be supplied to the engine 22 to lower the temperature of the exhaust gas purification catalyst, or at least the temperature increase of the exhaust gas purification catalyst can be suppressed. As a result, even if the fuel cut is executed again in a relatively short time after the fuel cut is executed once, that is, even if the frequency of the fuel cut increases, the deterioration of the exhaust gas purification catalyst is satisfactorily suppressed. It becomes possible.

  Next, a hybrid vehicle 20B according to a second embodiment of the present invention will be described. The hybrid vehicle 20B of the second embodiment has basically the same hardware configuration as the hybrid vehicle 20 of the first embodiment. Therefore, in order to avoid redundant description, the same reference numerals as those of the hybrid vehicle 20 of the first embodiment are used for the hybrid vehicle 20B of the second embodiment, and detailed description thereof is omitted. In the second embodiment, the engine ECU 24 of the hybrid vehicle 20B executes a catalyst deterioration suppression determination routine of FIG. 11 instead of the catalyst deterioration suppression determination routine of FIG. This routine is also repeatedly executed every predetermined time (for example, every several msec).

  When the catalyst deterioration suppression determination routine of FIG. 11 is started, the CPU 24a of the engine ECU 24 executes input processing of data necessary for determination such as the catalyst bed temperature Tcat and the input limit Win of the battery 50 (step S400). Then, it is determined whether or not the input catalyst bed temperature Tcat is equal to or higher than a predetermined first temperature Tref1 (step S410). Here, the catalyst bed temperature Tcat and the input limit Win are input in the same manner as in the routine of FIG. Further, the first temperature Tref1 is determined based on a target bed temperature (for example, 920 ° C.) when the increase in the catalyst bed temperature Tcat is suppressed to such an extent that deterioration of the exhaust gas purification catalyst is suppressed. When the catalyst bed temperature Tcat is equal to or higher than the first temperature Tref1, the high temperature history flag Fexcathi is set to a value 1 (step S420), and whether or not the input limit Win input in step S400 is equal to or lower than the temporary limit value Win0. Is determined (step S430). The temporary limit value Win0 is determined in the same manner as in the routine of FIG. If the catalyst bed temperature Tcat is lower than the first temperature Tref1, it is further determined whether or not the catalyst bed temperature Tcat is equal to or higher than the second temperature Tref2 (step S440). The second temperature Tref2 is lower than the first temperature Tref1 that is determined based on a temperature that is less likely to deteriorate when the exhaust gas purification catalyst is exposed to a lean atmosphere due to fuel cut. For example, the temperature is set to 800 ° C. When the catalyst bed temperature Tcat is lower than the second temperature Tref2, it is considered that the exhaust gas purification catalyst is less likely to deteriorate even if the fuel cut is permitted, and the high temperature history flag Fexcati is set to 0 (step). S500), the fuel cut prohibition flag Fc is set to 0 (step S510). If the catalyst bed temperature Tcat is equal to or higher than the second temperature Tref2, it is determined in step S430 whether or not the input limit Win is equal to or less than the temporary limit value Win0. The temporary limit value Win0 is also determined in the same manner as in the routine of FIG.

  If it is determined in step S430 that the input limit Win is equal to or less than the temporary limit value Win0, it is further determined whether or not the high temperature history flag Fexcati is a value 1 (step S450), and the high temperature history flag Fexcati is 0. If there is, the first OT increase coefficient setting map illustrated in FIG. 10A and the first TA correction map (not shown) are read from the ROM 24b and set (step S460), and further, the fuel cut is performed to prohibit the fuel cut. Is set to a value 1 (step S470), and this routine is terminated once. If it is determined in step S430 that the input limit Win exceeds the temporary limit value Win0, it is determined whether or not the input limit Win is equal to or less than the limit value Win1 (step S480). The limit value Win1 is also determined in the same manner as in the routine of FIG. When the input limit Win is equal to or less than the limit value Win1, that is, when the charging power is equal to or greater than the limit value Win1, the fuel injection amount tends to be increased as compared with the first OT increase coefficient setting map. The second OT increase coefficient setting map and the second TA correction map (not shown) illustrated in (1) are read from the ROM 24b and set (step S490), and the fuel cut prohibition flag Fc is set to 1 (step S470). The routine is temporarily terminated. If it is determined in step S480 that the input limit Win exceeds the limit value Win1, the fuel cut prohibition flag Fc is set to 0 to cancel the fuel cut prohibition according to the state of the battery 50. (Step S510). In the catalyst deterioration suppression routine of FIG. 11, even when it is determined in step S430 that the input limit Win is equal to or less than the temporary limit value Win0, the high temperature history flag Fexcati is a value 1 in step S450. Is determined, the second OT increase coefficient setting map illustrated in FIG. 10B and the second TA correction map (not shown) having a tendency to increase the fuel injection amount more than the first OT increase coefficient setting map. Is set (step S490).

  Thus, in the hybrid vehicle 20B according to the second embodiment, when the detected or estimated catalyst bed temperature Tcat is equal to or higher than the first temperature Tref1, the catalyst bed temperature Tcat may cause catalyst deterioration when the fuel is cut. A second OT increase coefficient setting map having a tendency to increase the fuel injection amount until the catalyst bed temperature Tcat becomes lower than the second temperature Tref2 lower than the first temperature Tref1 is regarded as having entered a certain high temperature range. Is set. As a result, the prohibition of fuel cut is canceled based on the input restriction Win, and it is assumed that the temperature of the exhaust gas purifying catalyst has entered a high temperature range that may cause catalyst deterioration at the time of fuel cut due to the execution of the fuel cut. However, when fuel injection is resumed after the fuel cut, more fuel can be supplied to the engine 22 to lower the temperature of the exhaust gas purification catalyst, or at least the temperature increase of the exhaust gas purification catalyst can be suppressed. Therefore, even if the fuel cut is executed again in a relatively short time after the fuel cut is executed once, that is, even if the frequency of the fuel cut increases, the deterioration of the exhaust gas purification catalyst is satisfactorily suppressed. Is possible.

  Subsequently, a hybrid vehicle 20C according to a third embodiment of the present invention will be described. The hybrid vehicle 20C of the third embodiment also has basically the same hardware configuration as the hybrid vehicle 20 of the first embodiment. Therefore, hereinafter, in order to avoid redundant description, the same reference numerals as those of the hybrid vehicle 20 of the first embodiment are used for the hybrid vehicle 20C of the third embodiment, and detailed description thereof is omitted. The hybrid vehicle 20C of this embodiment includes a G sensor (gradient detection means) that detects acceleration in the longitudinal direction of the vehicle, a laser radar or a millimeter wave radar for acquiring information such as the presence or absence of a preceding vehicle, and the distance between vehicles. A radar sensor and a navigation system (both not shown) are provided. Then, the engine ECU 24 of the hybrid vehicle 20C executes a catalyst deterioration suppression determination routine of FIG. 12 instead of the catalyst deterioration suppression determination routine of FIG. This routine is also repeatedly executed every predetermined time (for example, every several msec).

  When the catalyst deterioration suppression determination routine of FIG. 12 is started, the CPU 24a of the engine ECU 24, in addition to the catalyst bed temperature Tcat and the input limit Win of the battery 50, the road surface gradient θ in the vehicle longitudinal direction, the presence / absence of a preceding vehicle, the preceding vehicle Input processing of data necessary for the determination such as the inter-vehicle distance, presence / absence of signals, and vehicle information such as traffic jam information is executed (step S600). The road surface gradient θ in the longitudinal direction of the vehicle is calculated based on the acceleration in the longitudinal direction of the vehicle detected by the G sensor and is stored in a predetermined storage area. The presence / absence of the preceding vehicle and the inter-vehicle distance from the preceding vehicle are input as acquired by the radar sensor and stored in the storage area. In addition, the presence / absence of traffic signals and traffic jam information are input by the navigation system. After such data input processing, it is determined whether or not the input catalyst bed temperature Tcat is equal to or higher than a predetermined reference temperature Tref (for example, 800 ° C.) (step S610), and the catalyst bed temperature Tcat is When the temperature is lower than the reference temperature Tref, it is considered that there is little possibility that the exhaust gas purification catalyst will deteriorate even if the fuel cut is allowed, and the fuel cut prohibition flag Fc is set to 0 (step S680).

  When it is determined that the catalyst bed temperature Tcat is equal to or higher than the reference temperature Tref and the exhaust gas purification catalyst is in a high temperature state to some extent, it is determined whether or not the input limit Win input in step S600 is equal to or lower than the temporary limit value Win0. (Step S620). The temporary limit value Win0 is also determined in the same manner as in the routine of FIG. If it is determined in step S620 that the input limit Win is less than or equal to the temporary limit value Win0, the driver may set the shift position SP to the B position based on the vehicle information input in step S600. Determination is made (step S630). In this case, when the road surface gradient θ input in step S600 is less than the predetermined value and the traveling road surface is regarded as not having a relatively large slope, there is no preceding vehicle, or there is no distance between the preceding vehicle and the preceding vehicle. When the distance is less than the predetermined value, and further, when the distance to the signal is relatively long or when there is no traffic jam, the driver is unlikely to set the shift position SP to the B position. To be judged. When it is determined that the possibility of setting the B position is low, a first OT increase coefficient setting map illustrated in FIG. 10A and a first TA correction map (not shown) are read from the ROM 24b and set (step S640). Further, in order to prohibit the fuel cut, the fuel cut prohibition flag Fc, which is set to 0 when allowing the fuel cut, is set to the value 1 (step S650), and this routine is terminated once. If it is determined in step S620 that the input limit Win exceeds the temporary limit value Win0, it is determined whether or not the input limit Win is equal to or less than the limit value Win1 (step S660). The limit value Win1 is also determined in the same manner as in the routine of FIG. When the input limit Win is equal to or less than the limit value Win1, that is, when the charging power is equal to or greater than the limit value Win1, the fuel injection amount tends to be increased as compared with the first OT increase coefficient setting map. The second OT increase coefficient setting map and the second TA correction map (not shown) illustrated in FIG. 6 are read from the ROM 24b and set (step S670), and the fuel cut prohibition flag Fc is set to 1 (step S650). The routine is temporarily terminated. If it is determined in step S660 that the input limit Win exceeds the limit value Win1, the fuel cut prohibition flag Fc is set to 0 to cancel the fuel cut prohibition according to the state of the battery 50. (Step S680). In the catalyst deterioration suppression routine of FIG. 12, even if it is determined in step S620 that the input limit Win is less than or equal to the temporary limit value Win0, the shift position SP is set to the B position by the driver in step S630. If it is determined that there is a high possibility that the fuel injection amount will be set, the second OT increase factor setting map illustrated in FIG. 10B, which has a tendency to increase the fuel injection amount more than the first OT increase factor setting map. A second TA correction map (not shown) is set (step S670).

  As described above, in hybrid vehicle 20C, it is determined that input limit Win is equal to or less than temporary limit value Win0, and travel is required based on the vehicle information relating to the travel road surface, the relationship with the preceding vehicle, or the travel environment. The shift position SP of the shift position SP as a plurality of operating conditions that defines the driving force setting constraint for setting the required driving force and the operating point constraint for setting the operating point of the engine 22 corresponding to the required driving force, respectively. If it is determined that there is a high possibility that the B position for setting the required braking force based on the accelerator off from the inside will be selected, the second OT increase coefficient setting map that tends to increase the fuel injection amount will be displayed. Is set. Thus, the B position is actually selected based on the input restriction Win, which increases the possibility that the prohibition of fuel cut is released, even though the exhaust gas purifying catalyst is in a relatively high temperature state compared to the D position selection. Before that, a large amount of fuel can be supplied to the engine 22 in advance to lower the temperature of the exhaust gas purification catalyst, or at least the temperature increase of the exhaust gas purification catalyst can be suppressed. Therefore, even if the fuel cut is executed in a relatively short time after the B position is set by the driver, it is possible to satisfactorily suppress the deterioration of the exhaust gas purification catalyst.

  As mentioned above, although the embodiment of the present invention has been described using the examples, the present invention is not limited to the above-described examples at all, and various modifications are made without departing from the gist of the present invention. Needless to say, you get.

  That is, as in the above-described embodiments, the fuel injection amount is increased according to the first and second OT increase coefficient setting maps as an increase restriction that defines the increase amount of the fuel injection amount, thereby suppressing deterioration of the exhaust gas purification catalyst. At this time, in consideration of the possibility that the prohibition of fuel cut is canceled based on the input restriction Win even though the exhaust gas purification catalyst is in a relatively high temperature state, the first and second OT increase coefficient setting maps are used. When the temperature of the exhaust gas purification catalyst (catalyst bed temperature) detected or estimated when increasing the fuel injection amount is within a predetermined temperature range, a predetermined amount (for example, several) is used instead of keeping the air-fuel ratio at the stoichiometric air-fuel ratio. The fuel injection amount may be increased by about%).

  In the hybrid vehicles 20, 20B and 20C in each of the above embodiments, the ring gear shaft 32a as the drive shaft and the motor MG2 are connected via the reduction gear 35 that reduces the rotational speed of the motor MG2 and transmits it to the ring gear shaft 32a. However, instead of the reduction gear 35, there are, for example, two shift stages of Hi and Lo, or three or more shift stages, and a transmission that changes the rotational speed of the motor MG2 and transmits it to the ring gear shaft 32a. May be adopted.

  Furthermore, in the hybrid vehicles 20, 20B and 20C of the above embodiments, the power of the motor MG2 is decelerated by the reduction gear 35 and output to the ring gear shaft 32a, but the hybrid vehicle 120 as a modification shown in FIG. As described above, the power of the motor MG2 is changed by the transmission 65 and connected to the wheels 63c and 63d in FIG. 13 which are different from the axle to which the ring gear shaft 32a is connected (the axle to which the drive wheels 63a and 63b are connected). Transmission axle).

  The hybrid vehicles 20, 20B and 20C of the above embodiments output the power of the engine 22 to the ring gear shaft 32a as the drive shaft connected to the drive wheels 63a and 63b via the power distribution and integration mechanism 30. However, like an alternative hybrid vehicle 220 shown in FIG. 14, an inner rotor 232 connected to the crankshaft 26 of the engine 22 and an outer rotor connected to a drive shaft that outputs power to the drive wheels 63a and 63b. 234, and a counter-rotor motor 230 that transmits a part of the power of the engine 22 to the drive shaft and converts the remaining power into electric power.

1 is a schematic configuration diagram of a hybrid vehicle 20 according to a first embodiment of the present invention. 2 is a schematic configuration diagram of an engine 22. FIG. 5 is a flowchart illustrating an example of a drive control routine that is executed by a hybrid ECU 70 when an accelerator is on. It is explanatory drawing which shows an example of the relationship between the battery temperature Tb in the battery 50, and the input / output restrictions Win and Wout. It is explanatory drawing which shows an example of the relationship between the remaining capacity (SOC) of the battery 50, and the correction coefficient of input / output restrictions Win and Wout. It is explanatory drawing which shows an example of the map for request | requirement torque setting. It is explanatory drawing which illustrates the operation line of the engine 22, the correlation curve of target rotational speed Ne *, and target torque Te *. 3 is a collinear diagram illustrating a dynamic relationship between the rotational speed and torque of each rotary element in the power distribution and integration mechanism 30. FIG. It is a flowchart which shows an example of the catalyst deterioration suppression determination routine performed by engine ECU24 of a 1st Example. (A) is explanatory drawing which illustrates the 1st OT increase coefficient setting map, (b) is explanatory drawing which illustrates the 2nd OT increase coefficient setting map. It is a flowchart which shows an example of the catalyst deterioration suppression determination routine performed by engine ECU24 of the hybrid vehicle 20B which concerns on 2nd Example of this invention. It is a flowchart which shows an example of the catalyst deterioration suppression determination routine performed by engine ECU24 of the hybrid vehicle 20C which concerns on 3rd Example of this invention. It is a schematic block diagram of the hybrid vehicle 120 of the modification. FIG. 11 is a schematic configuration diagram of a hybrid vehicle 220 of a modification example.

Explanation of symbols

  20, 20B, 20C, 120, 220 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 24a, 72 CPU, 24b, 74 ROM, 24c, 76 RAM, 26 crankshaft, 28 damper, 30 power Distribution and integration mechanism, 31 sun gear, 32 ring gear, 32a ring gear shaft, 33 pinion gear, 34 carrier, 35 reduction gear, 40 motor electronic control unit (motor ECU), 41, 42 inverter, 43, 44 rotational position detection sensor, 50 battery , 51 temperature sensor, 52 battery electronic control unit (battery ECU), 54 power line, 60 gear mechanism, 62 differential gear, 63a, 63b driving wheel, 63c, 63d wheel, 65 transmission, 70 high Electronic control unit for lid (hybrid ECU), 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor, 122 air cleaner, 124 throttle valve, 126 fuel injection valve, 128 intake valve, 130 spark plug, 132 piston, 134 purification device, 135 temperature 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 Air flow meter, 149 Temperature sensor, 15 Variable valve timing mechanism, 230 pair-rotor motor, 232 an inner rotor, 234 outer rotor, MG1, MG2 motor.

Claims (8)

An internal combustion engine;
Purification means including a catalyst for purifying exhaust gas discharged from the internal combustion engine;
Catalyst high temperature history determination means for determining whether or not the temperature of the catalyst has entered a predetermined high temperature range that may cause deterioration of the catalyst when fuel supply to the internal combustion engine is stopped;
Power power input / output means connected to the first axle as one of the axles and the output shaft of the internal combustion engine and capable of inputting / outputting power to / from the first axle and the output shaft with input / output of power and power When,
An electric motor capable of inputting / outputting power to / from a second axle that is either the first axle or an axle different from the first axle;
Power storage means capable of exchanging power between the power drive input / output means and the electric motor;
Charge allowable power setting means for setting charge allowable power that is power allowed for charging of the power storage means based on the state of the power storage means;
Fuel supply stop determination means for determining that the stop of fuel supply should be prohibited when the set charge allowable power is equal to or greater than a predetermined limit value as charge power ;
When the set charge allowable power is equal to or greater than the temporary limit value, which is a value larger than the limit value as the charge power, the amount of increase in the fuel supply amount to the internal combustion engine for adjusting the temperature of the catalyst while it sets as first execution bulking constraint increased constraint of the plurality of extender constraints that define each and the set allowable charging power is less than the temporary limit value as charging power, increased restrictions for the execution The second increase restriction having a tendency to increase the fuel supply amount more than the first increase restriction is set, and the catalyst even if the set charge allowable power is not less than the temporary limit value. An increase restriction setting means for setting the second increase restriction as the execution increase restriction until a predetermined release condition is satisfied;
A required driving force setting means for setting a required driving force required for traveling;
Based on the determination result by the fuel supply stop determination means, the internal combustion engine is operated with the increase in the fuel supply amount in accordance with the set execution increase constraint, and based on the set required driving force Control means for controlling the internal combustion engine, the power drive input / output means and the electric motor so that a driving force is output;
A hybrid vehicle comprising: The hybrid vehicle according to claim 1 ,
When the fuel supply to the internal combustion engine is stopped when any increase restriction is to be set as the execution increase restriction by the increase restriction setting means, the catalyst high temperature history determination means determines the temperature of the catalyst. A hybrid vehicle that determines that the vehicle has entered the high temperature range. The hybrid vehicle according to claim 2 , wherein the release condition is satisfied when a predetermined time or more has elapsed since the fuel supply to the internal combustion engine was stopped. In the hybrid vehicle according to claim 2 or 3 ,
A catalyst temperature acquisition means for acquiring the temperature of the catalyst;
The fuel supply stop determination means prohibits the fuel supply stop when the acquired catalyst temperature is equal to or higher than a predetermined temperature and the set charge allowable power is equal to or higher than a predetermined limit value as charge power. Judging that
The increase restriction setting means sets any increase restriction as an execution increase restriction on the basis of the charge allowable power or the determination result of the catalyst high temperature history determination means when the temperature of the catalyst is equal to or higher than the predetermined temperature. Hybrid vehicle. The hybrid vehicle according to claim 2 ,
A catalyst temperature acquisition means for detecting or estimating the temperature of the catalyst;
The catalyst high temperature history determination means determines that the temperature of the catalyst has entered the high temperature range when the detected or estimated temperature of the catalyst is equal to or higher than a first temperature, and the release condition is satisfied. The hybrid vehicle when the detected or estimated temperature of the catalyst becomes lower than a second temperature lower than the first temperature. The hybrid vehicle according to claim 5 ,
The fuel supply stop determination means is configured to detect the fuel supply when the acquired catalyst temperature is equal to or higher than the second temperature and the set allowable charging power is equal to or higher than a predetermined limit value as charging power. Judging that the suspension should be prohibited,
The increase restriction setting means sets any increase restriction as an execution increase restriction based on the charge allowable power or the determination result of the catalyst high temperature history determination means when the temperature of the catalyst is equal to or higher than the second temperature. Hybrid vehicle to set.   The power power input / output means is connected to the first axle, the output shaft of the internal combustion engine, and a rotatable third shaft, and based on power input / output to any two of these three shafts. The hybrid vehicle according to any one of claims 1 to 7, further comprising: a three-axis power input / output unit that inputs / outputs a fixed power to / from a remaining shaft; and a generator capable of inputting / outputting power to / from the third shaft. An internal combustion engine;
Purification means including a catalyst for purifying exhaust gas discharged from the internal combustion engine;
Power power input / output means connected to the first axle as one of the axles and the output shaft of the internal combustion engine and capable of inputting / outputting power to / from the first axle and the output shaft with input / output of power and power When,
An electric motor capable of inputting / outputting power to / from a second axle that is either the first axle or an axle different from the first axle;
Power storage means capable of exchanging power between the power drive input / output means and the electric motor;
Charge allowable power setting means for setting charge allowable power that is power allowed for charging of the power storage means based on the state of the power storage means;
Fuel supply stop determination means for determining that the stop of fuel supply should be prohibited when the set charge allowable power is equal to or greater than a predetermined limit value as charge power ;
A plurality of drivings that define driving force setting constraints for setting a required driving force required for traveling and driving point constraints for setting an operating point of the internal combustion engine corresponding to the required driving force in different modes. An operation condition setting means for setting any one of the conditions as an operation condition for execution;
Vehicle information acquisition means for acquiring vehicle information related to at least one of a traveling road surface, a relationship with a preceding vehicle, and a traveling environment;
Determining means for determining a possibility that a predetermined driving condition having a driving force setting constraint having a relatively small lower limit of a power range is set as the execution driving condition based on the acquired vehicle information;
When the set charge allowable power is equal to or greater than the temporary limit value, which is a value larger than the limit value as the charge power, the amount of increase in the fuel supply amount to the internal combustion engine for adjusting the temperature of the catalyst while it sets as first execution bulking constraint increased constraint of the plurality of extender constraints that define each and the set allowable charging power is less than the temporary limit value as charging power, increased restrictions for the execution The second increase restriction having a tendency to increase the fuel supply amount more than the first increase restriction is set, and the execution is performed even if the set charge allowable power is not less than the temporary limit value. An increase restriction setting means for setting the second increase restriction as the execution increase restriction when it is determined that the predetermined operation condition is highly likely to be set as the operation condition;
Driving force / operating point setting means for setting the required driving force and the target operating point of the internal combustion engine based on the set operating condition for execution;
The internal combustion engine is operated at the set target operation point with the increase in the fuel supply amount in accordance with the set execution increase restriction according to the determination result by the fuel supply stop determination means, and Control means for controlling the internal combustion engine, the electric power drive input / output means and the electric motor so that a driving force based on the set required driving force is output;
A hybrid vehicle comprising:

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