JP2010241204A - Power output apparatus, hybrid vehicle provided with the same, and method of controlling power output apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power output apparatus etc., that makes variation in rotation speed of an internal combustion engine more suitable when a request to reduce the speed of a driving shaft is made while fuel reduction is inhibited so as to suppress catalyst deterioration. <P>SOLUTION: When a request to reduce the rotation speed of a ring gear shaft is made while the fuel reduction is inhibited so as to suppress the catalyst deterioration, the engine and motors MG1, MG2 are controlled (S160 to S200) so that the rotation speed Ne of an engine decreases to a rotation speed Nidle, and torque based on requested torque Tr* is obtained in connection with negative torque output from a motor MG1 and fuel injection. When the rotation speed Ne reaches the idle rotation speed Nidle, the engine and motors MG1, MG2 are controlled (S220, S170 to S200) so that the rotation speed Ne is held at the rotation speed Nidle, and the torque based on the requested torque Tr* is obtained in connection with the torque output from the motor MG1 and fuel injection. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a power output apparatus, a hybrid vehicle including the same, and a control method for the power output apparatus.

  Conventionally, an internal combustion engine, a planetary gear mechanism including a planetary carrier connected to a crankshaft of the internal combustion engine, a first electric motor capable of generating electricity connected to a sun gear of the planetary gear mechanism, and a ring gear of the planetary gear mechanism There is known a power output device including a second electric motor capable of outputting power to a ring gear shaft as a drive shaft and a battery capable of exchanging electric power with the first and second motors (for example, Patent Document 1). reference). In this power output device, when the catalyst that purifies the exhaust gas of the internal combustion engine is at a set temperature or higher, the fuel supply stop (fuel cut) in the internal combustion engine is prohibited and the fuel cut is prohibited in order to suppress deterioration of the catalyst. When a deceleration request for the drive shaft is made during the operation, the internal combustion engine is controlled so that the output torque becomes 0, and the rotational speed of the internal combustion engine is maintained at the value at that time by the first electric motor. Further, the second electric motor is controlled so as to output the regenerative braking force. In addition, this type of power output apparatus has an explosive combustion (fire) of an internal combustion engine when a brake pedal is depressed while a value of 1 is set in the catalyst deterioration suppression flag and suppression of catalyst deterioration is requested. Also known is that the motor (first electric motor) is controlled so that the rotational speed of the internal combustion engine decreases to a predetermined target rotational speed (for example, 800 to 1000 rpm) while the ring) is continued, and then the internal combustion engine is operated independently. (For example, refer to Patent Document 2).

JP 2004-340102 A JP 2007-084034 A

  As in the technique described in Patent Document 1, when the deceleration request for the drive shaft is made while the fuel cut is prohibited in order to suppress the deterioration of the catalyst, the rotation speed of the internal combustion engine is set by the first electric motor. By maintaining or further increasing, the braking force by so-called engine braking is output to the drive shaft, and the battery is overcharged by the electric power regenerated by the second electric motor by consuming electric power by the first electric motor. Can be suppressed. However, if the speed of the internal combustion engine is maintained even though a deceleration request is made, there is a risk that the passenger of the vehicle equipped with the power output device may feel uncomfortable. Therefore, when a deceleration request for the drive shaft is made while fuel cut is prohibited in order to suppress catalyst deterioration, the internal combustion engine is controlled by controlling the first electric motor as in the technique described in Patent Document 2 above. It is preferable to reduce the engine speed. However, if the internal combustion engine is autonomously operated after reducing the rotational speed of the internal combustion engine to a predetermined target rotational speed while continuing the explosion combustion of the internal combustion engine, the rotational speed of the internal combustion engine temporarily increases and the power output device May cause a passenger to feel uncomfortable.

  Therefore, the power output apparatus according to the present invention, the hybrid vehicle equipped with the power output apparatus, and the control method for the power output apparatus are provided for the drive shaft while the fuel supply to the internal combustion engine is prohibited from being stopped in order to suppress the deterioration of the catalyst. The main purpose is to make the change in the rotational speed of the internal combustion engine more appropriate when a deceleration request is made.

  The power output apparatus according to the present invention, the hybrid vehicle including the power output apparatus, and the control method for the power output apparatus employ the following means in order to achieve the main object described above.

The power output device according to the present invention is:
A power output device that outputs power to a drive shaft,
An internal combustion engine;
A purification device including a catalyst for purifying exhaust gas discharged from the internal combustion engine;
A first electric motor capable of inputting and outputting power;
Connected to the three shafts of the engine shaft of the internal combustion engine, the rotating shaft of the first electric motor, and the drive shaft, and the power based on the power input to and output from any two of these three shafts is used as the remaining shaft Power distribution means for input and output;
A second electric motor capable of inputting and outputting power to the drive shaft;
A power storage device capable of exchanging electric power with the first and second electric motors;
Requested torque setting means for setting a requested torque required for the drive shaft;
A negative torque from the first electric motor to the engine shaft when a deceleration request is made to the drive shaft while stopping the fuel supply of the internal combustion engine is prohibited in order to suppress deterioration of the catalyst. The internal combustion engine is configured so that the rotational speed of the internal combustion engine decreases to a predetermined idle rotational speed with the output of the engine and the fuel supply, and torque based on the set required torque is output to the drive shaft. And the first and second electric motors, and when the rotational speed of the internal combustion engine reaches the idle rotational speed, the torque output from the first motor to the engine shaft and the fuel supply are accompanied by The internal combustion engine and the first and second electric motors such that the rotational speed of the internal combustion engine is maintained at the idle rotational speed and torque based on the set required torque is output to the drive shaft. And control means for controlling,
Is provided.

  In this power output apparatus, when a deceleration request for the drive shaft is made while the stop of fuel supply to the internal combustion engine is prohibited in order to suppress deterioration of the catalyst, the negative output from the first electric motor to the engine shaft is made. The internal combustion engine and the first and second electric motors are configured such that the rotational speed of the internal combustion engine decreases to a predetermined idle rotational speed with torque output and fuel supply, and torque based on the required torque is output to the drive shaft. And are controlled. When the rotational speed of the internal combustion engine reaches the idle rotational speed, the rotational speed of the internal combustion engine is maintained at the idle rotational speed with the torque output from the first motor to the engine shaft and the fuel supply, and the required torque is achieved. The internal combustion engine and the first and second electric motors are controlled so that the based torque is output to the drive shaft. As a result, it is possible to suppress fluctuations in the rotational speed that cause the rotational speed of the internal combustion engine to rise again when the rotational speed of the internal combustion engine is reduced to the idle rotational speed by the first electric motor. Therefore, in this power output apparatus, when a deceleration request for the drive shaft is made while stopping the fuel supply of the internal combustion engine is prohibited in order to suppress the deterioration of the catalyst, the change in the rotational speed of the internal combustion engine is further reduced. It becomes possible to make it appropriate.

  The power distribution means includes a first element connected to the rotation shaft of the first electric motor, a second element connected to the engine shaft of the internal combustion engine, and a third element connected to the drive shaft. And a planetary gear mechanism configured such that these three elements can be differentially rotated with respect to each other.

  A hybrid vehicle according to the present invention includes any one of the power output devices described above and drive wheels connected to the drive shaft. In this hybrid vehicle, when a deceleration request for the drive shaft is made while stopping the fuel supply of the internal combustion engine is prohibited in order to suppress the deterioration of the catalyst, the change in the rotational speed of the internal combustion engine is more appropriate. It becomes possible.

The method for controlling the power output apparatus according to the present invention includes:
An internal combustion engine, a purification device including a catalyst for purifying exhaust gas discharged from the internal combustion engine, a first electric motor capable of inputting and outputting power, an engine shaft of the internal combustion engine, and a rotary shaft of the first electric motor Power distribution means connected to three axes of the drive shaft and for inputting / outputting power to / from the remaining shaft based on power input / output to / from any two of these three axes, and power input / output to / from the drive shaft A method for controlling a power output apparatus comprising: a second electric motor capable of power transmission and a power storage device capable of exchanging electric power with the first and second motors,
(A) When a deceleration request for the drive shaft is made while stopping the fuel supply of the internal combustion engine to inhibit deterioration of the catalyst, the first electric motor to the engine shaft With the output of the negative torque and the fuel supply, the rotational speed of the internal combustion engine decreases to a predetermined idle rotational speed, and torque based on the set required torque is output to the drive shaft. Controlling the internal combustion engine and the first and second electric motors;
(B) After the rotational speed of the internal combustion engine reaches the idle rotational speed, the rotational speed of the internal combustion engine is set to the idle rotational speed together with the output of torque from the first electric motor to the engine shaft and the fuel supply. Controlling the internal combustion engine and the first and second electric motors such that a torque based on the set required torque is output to the drive shaft while being maintained at a number,
Is included.

  According to this method, when a deceleration request for the drive shaft is made while the stop of fuel supply to the internal combustion engine is prohibited in order to suppress deterioration of the catalyst, a more appropriate change in the rotational speed of the internal combustion engine is made. It becomes possible.

1 is a schematic configuration diagram of a hybrid vehicle 20 according to an embodiment of the present invention. 2 is a schematic configuration diagram of an engine 22. FIG. It is explanatory drawing which shows an example of the relationship between 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 a flowchart which shows an example of the drive control routine at the time of accelerator off performed by hybrid ECU70 of an Example. It is explanatory drawing which shows an example of the map for request | requirement torque setting. 3 is an explanatory diagram showing an example of a collinear diagram showing a dynamic relationship between the number of rotations and torque in a rotating element of the power distribution and integration mechanism 30. FIG. It is a schematic block diagram of the hybrid vehicle 20B which concerns on a modification.

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

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

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

  The engine 22 configured in this way is controlled by an engine electronic control unit (hereinafter referred to as “engine ECU”) 24. As shown in FIG. 2, the engine ECU 24 is configured as a microprocessor centered on a CPU 24a. In addition to the CPU 24a, a ROM 24b that stores various processing programs, a RAM 24c that temporarily stores data, an input / output port (not shown). And communication ports. Then, signals from various sensors that detect the state of the engine 22 and the like are input to the engine ECU 24 via an input port (not shown). For example, the engine ECU 24 includes a crank position from a crank position sensor 180 that detects the rotational position of the crankshaft 26, a cooling water temperature Tw from a water temperature sensor 181 that detects the temperature of cooling water in the engine 22, and a pressure in the combustion chamber 120. A cylinder position from a cylinder pressure sensor 182 that detects the rotational position of a camshaft included in a valve operating mechanism 130 that drives the intake valve 131 and the exhaust valve 132; The throttle position from the throttle valve position sensor 124 for detecting the position of the engine, the intake air amount GA from the air flow meter 183 for detecting the intake air amount as a load of the engine 22, and the intake air temperature sensor 184 attached to the intake pipe 126 Intake air temperature Tair, intake negative pressure Pi from intake pressure sensor 185 for detecting negative pressure in intake pipe 126, air-fuel ratio AF from air-fuel ratio sensor 186 disposed upstream of purification device 141 of exhaust manifold 140, purification device 141 The catalyst bed temperature Tcat from the catalyst temperature sensor 187 for detecting the temperature of the catalyst bed (the temperature of the exhaust gas purification catalyst 141c), the EGR gas temperature from the temperature sensor 144 of the EGR pipe 142, and the like are input via the input port. The engine ECU 24 outputs various control signals for driving the engine 22 through an output port (not shown). For example, the engine ECU 24 controls the position of the throttle valve 123, a drive signal to the throttle motor 125, a drive signal to the fuel injection valve 127, a control signal to the ignition coil 129 integrated with the igniter, and the valve mechanism 130. Control signal, a drive signal to the EGR valve 143, and the like are output via an output port. Further, the engine ECU 24 calculates the rotational speed Ne of the engine 22 using the crank position from the crank position sensor 180. Further, the engine ECU 24 is in communication with the hybrid ECU 70, controls the operation of the engine 22 by a control signal from the hybrid ECU 70, and outputs data related to the operation state of the engine 22 to the hybrid ECU 70 as necessary.

  The power distribution and integration mechanism 30 includes an external gear sun gear 31, an internal gear ring gear 32 disposed 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, This is a single pinion type planetary gear mechanism that has a carrier 34 that holds a plurality of pinion gears 33 so as to rotate and revolve, and that these three elements can be differentially rotated with respect to each other. The sun gear 31 that is the first element of the power distribution and integration mechanism 30 has a rotating shaft of the motor MG1, the carrier 34 that is the second element, the crankshaft 26 of the engine 22, and the ring gear 32 that is the third element. The rotation shafts of the motor MG2 are connected to each other via a ring gear shaft 32a and a reduction gear 35 as shafts. The power distribution and integration mechanism 30 distributes the power from the engine 22 input from the carrier 34 to the sun gear 31 side and the ring gear 32 side according to the gear ratio when the motor MG1 functions as a generator. , The power from the engine 22 input from the carrier 34 and the power from the motor MG1 input from the sun gear 31 are integrated and output to the ring gear 32 side. The power output to the ring gear 32 is finally output from the ring gear shaft 32a to the wheels 39a and 39b, which are drive wheels, via the gear mechanism 37 and the differential gear 38.

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

  The battery 50 is configured as a lithium ion secondary battery or a nickel hydride secondary battery, and is managed by a battery electronic control unit (hereinafter referred to as “battery ECU”) 52. The battery ECU 52 receives signals necessary for managing the battery 50, for example, a voltage between terminals from a voltage sensor (not shown) installed between the terminals of the battery 50, and a power line 54 connected to the output terminal of the battery 50. A charge / discharge current from an attached current sensor (not shown), a battery temperature Tb from a temperature sensor 51 attached to the battery 50, and the like are input. The battery ECU 52 outputs data related to the state of the battery 50 to the hybrid ECU 70 by communication as necessary. Further, in order to manage the battery 50, the battery ECU 52 calculates the remaining capacity SOC based on the integrated value of the charging / discharging current detected by the current sensor, or requests charging / discharging of the battery 50 based on the remaining capacity SOC. The power Pb * is calculated, or the input limit Win as the allowable charging power, which is the power allowed for charging the battery 50 based on the remaining capacity SOC and the battery temperature Tb, and the power allowed for discharging the battery 50. The output limit Wout as the allowable discharge power is calculated. The input / output limits Win and Wout of the battery 50 set basic values of the input / output limits Win and Wout based on the battery temperature Tb, and output correction correction coefficients based on the remaining capacity (SOC) of the battery 50. It can be set by setting a correction coefficient for input restriction and multiplying the basic value of the set input / output restrictions Win and Wout by the correction coefficient. FIG. 3 shows an example of the relationship between the battery temperature Tb and the input / output limits Win, Wout, and FIG. 4 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.

  The hybrid ECU 70 is configured as a microprocessor centered on the CPU 72, and in addition to the CPU 72, a ROM 74 that stores a processing program, a RAM 76 that temporarily stores data, and a timer 78 that executes a timing process according to a timing command. , Provided with an input / output port and a communication port (not shown). The hybrid ECU 70 detects the ignition signal from the ignition switch (start switch) 80, the shift position SP from the shift position sensor 82 that detects the shift position SP that is the operation position of the shift lever 81, and the depression amount of the accelerator pedal 83. The accelerator opening Acc from the accelerator pedal position sensor 84, the brake pedal stroke BS from the brake pedal stroke sensor 86 for detecting the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 87, and the like are input via the input port. . As described above, the hybrid ECU 70 is connected to the engine ECU 24, the motor ECU 40, the battery ECU 52, etc. via the communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, the battery ECU 52, etc. ing.

  In the hybrid vehicle 20 of the embodiment configured as described above, a request to be 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. Torque Tr * is calculated, and engine 22 and motors MG1 and MG2 are controlled so that torque based on this required torque Tr * is output to ring gear shaft 32a. As the operation control mode of the engine 22 and the motors MG1 and MG2, the operation of the engine 22 is controlled so that the power corresponding to the required torque Tr * is output from the engine 22, and all the power output from the engine 22 is power distribution integrated. Torque conversion operation mode for driving and controlling the motors MG1 and MG2 so that the torque is converted by the mechanism 30 and the motors MG1 and MG2 and output to the ring gear shaft 32a, the required torque Tr * 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 of the power is output from the engine 22, and all or part of the power output from the engine 22 with charging / discharging of the battery 50 is the power distribution integration mechanism 30 and the motor. Requested with torque conversion by MG1 and MG2. A charge / discharge operation mode in which the motors MG1 and MG2 are driven and controlled so that torque based on the torque Tr * is output to the ring gear shaft 32a, and the engine 22 is stopped and torque based on the required torque Tr * is output to the ring gear shaft 32a. There is a motor operation mode for driving and controlling the motor MG2. Further, in the hybrid vehicle 20 of the embodiment, when a predetermined condition is satisfied under the torque conversion operation mode or the charge / discharge operation mode, intermittent operation for automatically stopping and starting the engine 22 is executed.

  Further, in the hybrid vehicle 20 of the embodiment, when a catalyst deterioration suppression determination routine (not shown) is executed by the engine ECU 24 and the exhaust gas purification catalyst 141c rises in temperature and the catalyst bed temperature Tcat of the purification device 141 becomes equal to or higher than the first temperature, The predetermined catalyst deterioration suppression flag Fc is set to a value of 1 until the catalyst bed temperature Tcat becomes lower than the second temperature lower than the first temperature. When the catalyst deterioration suppression flag Fc is set to the value 1, the driver returns the accelerator pedal 83 or depresses the brake pedal 85 so that the temperature of the catalyst bed further increases and the exhaust gas purification catalyst 141c does not deteriorate. Therefore, when the deceleration of the hybrid vehicle 20 (ring gear shaft 32a) is requested, the fuel cut of the engine 22 is performed so that the further temperature rise of the catalyst bed due to the supply of a large amount of air to the high-temperature exhaust gas purification catalyst 141c is suppressed. Is prohibited. That is, when the catalyst deterioration suppression flag Fc is set to a value of 1, the fuel injection into each combustion chamber 120 and the ignition of the mixer are executed even when the fuel cut of the engine 22 should be executed originally. .

  Next, the operation of the hybrid vehicle 20 when the catalyst deterioration suppression flag Fc is set to the value 1, particularly when the accelerator pedal 83 is depressed by the driver when the catalyst deterioration suppression flag Fc is set to the value 1. The operation when is canceled will be described.

  FIG. 5 shows that when the driver depresses the accelerator pedal 83 in a state where a normal forward drive position is selected as the shift position, the hybrid ECU 70 of the embodiment performs every predetermined time (for example, several msec). It is a flowchart which shows an example of the drive control routine at the time of accelerator OFF performed for every). At the start of the routine of FIG. 3, the CPU 72 of the hybrid ECU 70 determines the vehicle speed V from the vehicle speed sensor 87, the rotational speed Ne of the engine 22, the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2, the input / output limits Win and Wout of the battery 50, Input processing of data necessary for control such as the temperature Tb of the battery 50 and the value of the catalyst deterioration suppression flag Fc is executed (step S100). Here, the rotational speed Ne of the engine 22 is calculated by the engine ECU 24 based on the crank position from the crank position sensor 180 and is input from the engine ECU 24 by communication. The rotation speeds Nm1 and Nm2 of the motors MG1 and MG2 are calculated by the motor ECU 40 based on signals from the rotation position detection sensors 43 and 44, and are input from the motor ECU 40 by communication. Further, the input / output limits Win and Wout and the battery temperature Tb are input from the battery ECU 52 by communication. The catalyst deterioration suppression flag Fc is input from the engine ECU 24 by communication. After the data input process of step S100, it is determined whether or not the input catalyst deterioration suppression flag Fc is a value 1 (step S110). The catalyst deterioration suppression flag Fc is a value 0 and the exhaust gas purification catalyst 141c is deteriorated. When it is considered that there is no fear, normal accelerator-off control is executed (step S230), and this routine is once ended.

  If it is determined in step S110 that the catalyst deterioration suppression flag Fc is 1, the required torque Tr * to be output to the ring gear shaft 32a is set based on the vehicle speed V input in step S100 ( Step S120). In the embodiment, the relationship between the vehicle speed V and the required torque Tr * when the accelerator is off, that is, when the accelerator opening Acc is 0, is determined in advance and stored in the ROM 74 as a required torque setting map. As for *, the one corresponding to the given vehicle speed V is derived and set from the map. FIG. 6 shows an example of a required torque setting map used when the accelerator is off. Next, the target engine speed Ne * of the engine 22 is set to a predetermined idle engine speed Nidle (for example, 800 to 1200 rpm) (step S130). That is, when the catalyst deterioration suppression flag Fc is set to a value of 1 and fuel cut of the engine 22 is prohibited, the torque is substantially increased while continuing fuel injection into each combustion chamber 120 and ignition of the mixer. The engine 22 is idled (self-sustained operation) so as not to output.

  If the target rotational speed Ne * of the engine 22 is set, it is determined whether or not the predetermined flag F is 0 (step S140). If the flag F is 0, the engine input in step S100 is determined. It is determined whether or not the absolute value of the difference between the rotational speed Ne of 22 and the target rotational speed Ne * exceeds a predetermined value α (for example, a value of about 50 rpm) (step S150). When the absolute value of the difference between the rotational speed Ne and the target rotational speed Ne * exceeds a predetermined value α, the rotational speed Ne of the engine 22 is set by the output of negative torque from the motor MG1 to the crankshaft 26. In order to decrease, torque command Tm1 * for motor MG1 is set according to the following equation (1) (step S160). Here, Expression (1) is a relational expression in feedback control for reducing the rotational speed Ne of the engine 22 to the target rotational speed Ne * (idle rotational speed Nidle) while continuing fuel supply of the engine 22, that is, explosion combustion. It is. In Expression (1), “k1” in the first term on the right side is the gain of the proportional term, and “k2” in the second term on the right side is the gain of the integral term. These gains “k1” and “k2” are set to small values as compared with the case where a relatively large torque is output from the engine 22 because it is necessary to continue the explosion combustion of the engine 22.

  Tm1 * = k1 ・ (Ne * -Ne) + k2 ・ ∫ (Ne * -Ne) dt (1)

  Subsequently, even if output from the motor MG2 is performed using the input / output limits Win, Wout of the battery 50, the torque command Tm1 * for the motor MG1 set in step S210, and the current rotational speeds Nm1, Nm2 of the motors MG1, MG2. Torque limits Tmin and Tmax as upper and lower limits of good torque are calculated according to the following equations (2) and (3) (step S170). Further, a temporary motor torque Tm2tmp which is a temporary value of torque to be output from the motor MG2 using the required torque Tr *, the torque command Tm1 *, the gear ratio ρ of the power distribution and integration mechanism 30 and the gear ratio Gr of the reduction gear 35. Is calculated according to the following equation (4) (step S180). Then, the torque command Tm2 * for the motor MG2 is set to a value obtained by limiting the temporary motor torque Tm2tmp with the torque limits Tmin and Tmax (step S190). Thus, by setting the torque command Tm2 * for the motor MG2, the torque output to the ring gear shaft 32a as the axle can be limited within the range of the input / output limits Win and Wout of the battery 50. Here, Expression (4) is a dynamic relational expression for the rotating elements of the power distribution and integration mechanism 30. FIG. 7 illustrates a collinear diagram showing a dynamic relationship between the rotational speed and torque in the rotary element of the power distribution and integration mechanism 30. In the figure, the left S-axis indicates the rotational speed of the sun gear 31 that matches the rotational speed Nm1 of the motor MG1, the central C-axis indicates the rotational speed of the carrier 34 that matches the rotational speed Ne of the engine 22, and the right R-axis. The axis indicates the rotational speed Nr of the ring gear 32 obtained by dividing the rotational speed Nm2 of the motor MG2 by the gear ratio Gr of the reduction gear 35. The two thick arrows on the R axis indicate the torque acting on the ring gear shaft 32a by this torque output when the motor MG1 outputs the torque Tm1, and the reduction gear 35 when the motor MG2 outputs the torque Tm2. And the torque acting on the ring gear shaft 32a via. Expression (4) for obtaining the temporary motor torque Tm2tmp can be easily derived by using the rotational speed relationship in this alignment chart. Thus, if the target rotational speed Ne * of the engine 22 and the torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are set, the fuel cut prohibition for prohibiting the stop of fuel injection (fuel cut) into each combustion chamber 120 is prohibited. The command and the target rotational speed Ne * are transmitted to the engine ECU 24, and the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are transmitted to the motor ECU 40 (step S200), and this routine is temporarily terminated.

Tmin = (Win-Tm1 * ・ Nm1) / Nm2 (2)
Tmax = (Wout-Tm1 * ・ Nm1) / Nm2 (3)
Tm2tmp = (Tr * + Tm1 * / ρ) / Gr (4)

  The engine ECU 24 that has received the fuel cut command and the target rotational speed Ne * from the hybrid ECU 70 sets the target throttle opening TH * of the throttle valve 123 using the rotational speed Ne of the engine 22 and a predetermined map (not shown). At the same time, based on the throttle position from the throttle valve position sensor 124, the throttle motor 125 is controlled so that the opening degree of the throttle valve 123 becomes the target throttle opening degree TH *. Further, the engine ECU 24 uses the target throttle opening TH *, the rotational speed Ne, a predetermined map (not shown), and the like to continue the explosion combustion of the engine 22 and suppress the motor in order to suppress the deterioration of the exhaust gas purification catalyst 141c. Fuel injection control is performed so that the fuel injection amount that allows the rotational speed Ne to be quickly reduced by the output of torque from the MG 1 to the crankshaft 26 is set, and the set amount of fuel is supplied to each combustion chamber 120. And the ignition timing control is executed to continue the explosion combustion of the engine 22. 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. As a result, it is possible to quickly reduce the rotational speed Ne of the engine 22 to the target rotational speed Ne * (idle rotational speed Nidle) while continuing fuel supply of the engine 22, that is, explosion combustion.

  On the other hand, after an affirmative determination is made in step S140, the absolute value of the difference between the rotational speed Ne of the engine 22 and the target rotational speed Ne * becomes equal to or smaller than a predetermined value α in step S150, and the rotational speed Ne becomes the target rotational speed. If it is determined that it substantially coincides with Ne *, the above-mentioned flag F is set to a value 1 (step S210), and the rotational speed Ne of the engine 22 is set to the target by output of torque from the motor MG1 to the crankshaft 26. In order to maintain the rotational speed Ne *, that is, the idle rotational speed Nidle, a torque command Tm1 * for the motor MG1 is set according to the following equation (5) (step S220). Here, Expression (5) is a relational expression in feedback control for maintaining the rotation speed Ne of the engine 22 at the target rotation speed Ne * (idle rotation speed Nidle) while continuing fuel supply of the engine 22, that is, explosion combustion. is there. In equation (5), “k10” in the first term on the right side is the gain of the proportional term, and “k20” in the second term on the right side is the gain of the integral term. These gains “k10” and “k20” are gains “k1” in the above equation (1) so that the rotational speed Ne can be maintained at the target rotational speed Ne * by the motor MG1 while continuing the explosion combustion of the engine 22. , “K2”.

  Tm1 * = k10 ・ (Ne * -Ne) + k20 ・ ∫ (Ne * -Ne) dt (5)

  Then, the processing of steps S170 to S190 described above is executed, and the fuel cut command and the target rotational speed Ne * are transmitted to the engine ECU 24, and the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are transmitted to the motor ECU 40 (step). S200), this routine is temporarily terminated. Also in this case, the engine ECU 24 sets the target throttle opening TH * corresponding to the target rotational speed Ne *, that is, the idle rotational speed Nidle, and the opening of the throttle valve 123 based on the throttle position from the throttle valve position sensor 124. The throttle motor 125 is controlled so that becomes the target throttle opening TH *. Further, the engine ECU 24 sets the fuel injection amount during the self-sustaining operation at the idle rotation speed Nidle using the target throttle opening TH *, the rotation speed Ne, a predetermined map (not shown), and the like. Fuel injection control is executed so that fuel is supplied to each combustion chamber 120, and ignition timing control is executed to continue the explosion combustion of the engine 22. 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. Then, when the flag F is set to the value 1 in step S210 as described above, since a negative determination is made in step S140 thereafter, the processes in steps S210, S220 and S170 to S200 are executed. Will be.

  As described above, in the hybrid vehicle 20 of the embodiment, while the catalyst deterioration suppression flag Fc is set to the value 1, the fuel cut of the engine 22 is prohibited in order to suppress the deterioration of the exhaust gas purification catalyst 141c. When a deceleration request is made to the ring gear shaft 32a by releasing the accelerator pedal 83, negative torque output from the motor MG1 to the crankshaft 26 and fuel injection (and ignition) to each combustion chamber 120 are performed. Accordingly, the engine 22 and the motors MG1 and MG2 are controlled such that the rotational speed Ne of the engine 22 decreases to a predetermined idle rotational speed Nidle and torque based on the required torque Tr * is output to the ring gear shaft 32a. (Steps S160 to S200). When the rotational speed Ne of the engine 22 reaches the idle rotational speed Nidle (step S150), the engine is accompanied by torque output from the motor MG1 to the crankshaft 26 and fuel injection (and ignition) to each combustion chamber 120. The engine 22 and the motors MG1 and MG2 are controlled so that the rotational speed Ne of the motor 22 is maintained at the idle rotational speed Nidle and torque based on the required torque Tr * is output to the ring gear shaft 32a (steps S220, S170˜). S200). As a result, it is possible to suppress fluctuations in the rotational speed such that the rotational speed Ne of the engine 22 increases again when the rotational speed Ne of the engine 22 is reduced to the idle rotational speed Nidle by the motor MG1. Therefore, in the hybrid vehicle 20 of the embodiment, when the deceleration request for the ring gear shaft 32a is made while the fuel cut of the engine 22 is prohibited in order to suppress the deterioration of the exhaust gas purification catalyst 141c, the rotation of the engine 22 is performed. It becomes possible to make the number change more appropriate.

  Note that the battery 50 mounted in the hybrid vehicle 20 of the embodiment is such that the input limit Win, which is the power allowed for charging, is limited to a small value when the battery temperature Tb is equal to or higher than a predetermined temperature. Therefore, the negative torque output from the motor MG1 to the crankshaft 26 and each of the outputs only when the input limit Win of the battery 50 is not limited to a small amount as the charging power because of the relationship between the battery temperature Tb and the battery temperature Tb. With the fuel injection (and ignition) into the combustion chamber 120, the rotational speed Ne of the engine 22 is reduced to the idle rotational speed Nidle, and after the rotational speed Ne of the engine 22 reaches the idle rotational speed Nidle, the motor MG1 The rotational speed Ne of the engine 22 may be maintained at the idle rotational speed Nidle with the output of torque to the crankshaft 26 and the fuel injection (and ignition) into each combustion chamber 120. In this case, when the battery temperature Tb is relatively high and the input limit Win of the battery 50 is limited to be small as the charging power due to the relationship with the battery temperature Tb, the motor MG1 does not output torque to each combustion chamber 120. With the fuel injection (and ignition), the rotational speed Ne of the engine 22 is reduced to the idle rotational speed Nidle. After the rotational speed Ne of the engine 22 reaches the idle rotational speed Nidle, the engine MG1 starts the crankshaft. The rotational speed Ne of the engine 22 may be maintained at the idle rotational speed Nidle with the output of torque to 26 and the fuel injection (and ignition) into each combustion chamber 120.

  Further, the present invention has been described so far by taking as an example the case where the driver depresses the accelerator pedal 83 when the catalyst deterioration suppression flag Fc is set to a value of 1. Needless to say, the present invention can be similarly applied when the pedal is depressed or when the brake pedal 85 is depressed. Further, in the hybrid vehicle 20 described above, the ring gear shaft 32a as the axle and the motor MG2 are connected via the reduction gear 35 that reduces the rotational speed of the motor MG2 and transmits it to the ring gear shaft 32a. Instead of this, for example, a transmission that shifts the rotational speed of the motor MG2 having two shift stages of Hi and Lo or three or more shift stages and transmits it to the ring gear shaft 32a may be employed. Moreover, although the hybrid vehicle 20 of the embodiment outputs the power of the motor MG2 to the ring gear shaft 32a connected to the ring gear 32 of the power distribution and integration mechanism 30, the application target of the present invention is not limited to this. Absent. That is, in the present invention, the power of the motor MG2 is connected to a shaft (wheels 39c and 39d in FIG. 8) different from the ring gear shaft 32a (wheels 39a and 39b), as in the hybrid vehicle 20B according to the modification shown in FIG. It may be applied to the one that outputs to the other axis.

  Here, the correspondence between the main elements of the above-described embodiments and modifications and the main elements of the invention described in the column of means for solving the problems will be described. In other words, in the above-described embodiment, the engine 22 corresponds to the “internal combustion engine”, the purification device 141 including the exhaust gas purification catalyst 141c for purifying the exhaust gas discharged from the engine 22 corresponds to the “purification device”, and the power The motor MG1 that can input and output the motor MG1 corresponds to the “first electric motor”, and is connected to the crankshaft 26 of the engine 22, the rotation shaft of the motor MG1, and the ring gear shaft 32a as the drive shaft. The power distribution integration mechanism 30 that inputs / outputs power based on the power input / output to / from the shaft corresponds to “power distribution means”, and the motor MG2 that can output power to the ring gear shaft 32a is “second motor”. The battery 50 capable of exchanging electric power with the motors MG1 and MG2 corresponds to the “power storage device” and performs a process of step S120 in FIG. The ECU 70 corresponds to “request torque setting means” and the fuel deterioration of the engine 22 is prohibited while the catalyst deterioration suppression flag Fc is set to a value 1 and the deterioration of the exhaust gas purification catalyst 141c is suppressed. When a deceleration request is made to the ring gear shaft 32a by releasing the accelerator pedal 83, negative torque output from the motor MG1 to the crankshaft 26 and fuel injection (and ignition) to each combustion chamber 120 are performed. Accordingly, the engine 22 and the motors MG1 and MG2 are controlled so that the rotational speed Ne of the engine 22 decreases to a predetermined idle rotational speed Nidle and torque based on the required torque Tr * is output to the ring gear shaft 32a. When the rotational speed Ne of the engine 22 reaches the idle rotational speed Nidle, the motor MG1 With the output of torque to the rank shaft 26 and fuel injection (and ignition) to each combustion chamber 120, the rotational speed Ne of the engine 22 is maintained at the idle rotational speed Nidle, and the torque based on the required torque Tr * is changed to the ring gear. A combination of the hybrid ECU 70, the engine ECU 24, and the motor ECU 40 that controls the engine 22 and the motors MG1 and MG2 so as to be output to the shaft 32a corresponds to “control means”, and is a carrier connected to the crankshaft 26 of the engine 22. 34, a sun gear 31 connected to the rotation shaft of the motor MG1, and a ring gear 32 connected to a ring gear shaft 32a as a drive shaft, and these three elements can be differentially rotated with each other. 30 corresponds to a “planetary gear mechanism”.

  However, the “internal combustion engine” is not limited to the engine 22 that outputs power by receiving a hydrocarbon-based fuel such as gasoline or light oil, and may be of any other type such as a hydrogen engine. The “purification device” may be of any type as long as it includes an exhaust gas purification catalyst for purifying exhaust gas discharged from the engine 22. The “first motor” and the “second motor” are not limited to the synchronous generator motors such as the motors MG1 and MG2, and may be any other type such as an induction motor. The “power storage device” is not limited to the secondary battery such as the battery 50, and may be any other type such as a capacitor as long as it can exchange electric power with the motor. The “request torque setting means” is not limited to the one that sets the required torque based on the accelerator opening and the vehicle speed, but is of any other type such as one that sets the required driving force based only on the accelerator opening, for example. It does not matter. The “control means” may be of any type other than the combination of the hybrid ECU 70, the engine ECU 24, and the motor ECU 40, such as a single electronic control unit. In any case, the correspondence between the main elements of the embodiments and the modified examples and the main elements of the invention described in the column of means for solving the problem is the same as that of the means for the embodiment to solve the problem. Since the embodiment for carrying out the invention described in the column is an example for concretely explaining, the elements of the invention described in the column for means for solving the problems are not limited. In other words, the examples are merely specific examples of the invention described in the column of means for solving the problem, and the interpretation of the invention described in the column of means for solving the problem is described in the description of that column. Should be done on the basis.

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

  The present invention can be used in the manufacturing industry of power output devices and hybrid vehicles.

  20, 20B 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 integration mechanism, 31 sun gear , 32 ring gear, 32a ring gear shaft, 33 pinion gear, 34 carrier, 35 reduction gear, 37 gear mechanism, 38 differential gear, 39a to 39d wheels, 40 motor electronic control unit (motor ECU), 41, 42 inverter, 43, 44 Rotation position detection sensor, 50 battery, 51 temperature sensor, 52 battery electronic control unit (battery ECU), 54 power line, 70 hybrid electronic control unit (hybrid ECU), 78 timer 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal stroke sensor, 87 vehicle speed sensor, 120 combustion chamber, 121 piston, 122 air cleaner, 123 throttle valve 124 throttle valve position sensor, 125 throttle motor, 126 intake pipe, 127 fuel injection valve, 128 ignition plug, 129 ignition coil, 130 valve operating mechanism, 131 intake valve, 132 exhaust valve, 133 cam position sensor, 140 exhaust manifold, 141 purification device, 141c exhaust gas purification catalyst, 142 EGR pipe, 143 EGR valve, 144 temperature sensor, 180 crank Jishon sensor, 181 temperature sensor, 182 cylinder pressure sensor, 183 an air flow meter, 184 an intake air temperature sensor, 185 an intake pressure sensor, 186 an air-fuel ratio sensor, 187 a catalyst temperature sensor, MG1, MG2 motor.

Claims (4)

A power output device that outputs power to a drive shaft,
An internal combustion engine;
A purification device including a catalyst for purifying exhaust gas discharged from the internal combustion engine;
A first electric motor capable of inputting and outputting power;
Connected to the three shafts of the engine shaft of the internal combustion engine, the rotating shaft of the first electric motor, and the drive shaft, and the power based on the power input to and output from any two of these three shafts is used as the remaining shaft Power distribution means for input and output;
A second electric motor capable of inputting and outputting power to the drive shaft;
A power storage device capable of exchanging electric power with the first and second electric motors;
Requested torque setting means for setting a requested torque required for the drive shaft;
A negative torque from the first electric motor to the engine shaft when a deceleration request is made to the drive shaft while stopping the fuel supply of the internal combustion engine is prohibited in order to suppress deterioration of the catalyst. The internal combustion engine is configured so that the rotational speed of the internal combustion engine decreases to a predetermined idle rotational speed with the output of the engine and the fuel supply, and torque based on the set required torque is output to the drive shaft. And the first and second electric motors, and when the rotational speed of the internal combustion engine reaches the idle rotational speed, the torque output from the first motor to the engine shaft and the fuel supply are accompanied by The internal combustion engine and the first and second electric motors such that the rotational speed of the internal combustion engine is maintained at the idle rotational speed and torque based on the set required torque is output to the drive shaft. And control means for controlling,
A power output device comprising: The power output apparatus according to claim 1, wherein
The power distribution means includes a first element connected to a rotation shaft of the first electric motor, a second element connected to the engine shaft of the internal combustion engine, and a third element connected to the drive shaft. And a power output device which is a planetary gear mechanism configured so that these three elements can differentially rotate with each other.   A hybrid vehicle comprising the power output apparatus according to claim 1 and a drive wheel coupled to the drive shaft. An internal combustion engine, a purification device including a catalyst for purifying exhaust gas discharged from the internal combustion engine, a first electric motor capable of inputting and outputting power, an engine shaft of the internal combustion engine, and a rotary shaft of the first electric motor Power distribution means connected to three axes of the drive shaft and for inputting / outputting power to / from the remaining shaft based on power input / output to / from any two of these three axes, and power input / output to / from the drive shaft A method for controlling a power output apparatus comprising: a second electric motor capable of power transmission and a power storage device capable of exchanging electric power with the first and second motors,
(A) When a deceleration request for the drive shaft is made while stopping the fuel supply of the internal combustion engine to inhibit deterioration of the catalyst, the first electric motor to the engine shaft With the output of the negative torque and the fuel supply, the rotational speed of the internal combustion engine decreases to a predetermined idle rotational speed, and torque based on the set required torque is output to the drive shaft. Controlling the internal combustion engine and the first and second electric motors;
(B) After the rotational speed of the internal combustion engine reaches the idle rotational speed, the rotational speed of the internal combustion engine is set to the idle rotational speed together with the output of torque from the first electric motor to the engine shaft and the fuel supply. Controlling the internal combustion engine and the first and second electric motors such that a torque based on the set required torque is output to the drive shaft while being maintained at a number,
A method for controlling a power output apparatus including:

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