JP2010179864A - Control device for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device of a hybrid vehicle for suppressing the deterioration of the removal efficiency of nitrogen oxide. <P>SOLUTION: This control device of the hybrid vehicle having an internal combustion engine EG, a motor MG, and wheels RR and RL connected to the output shaft of the internal combustion engine or the motor is configured to output a control signal to a hybrid vehicle HEV, and provided with: oxygen storage quantity detection means 126 and 128 for detecting the oxygen storage quantity of an exhaust purification catalyst 127 installed in the exhaust system of the internal combustion engine; and a control means 1 for, when the oxygen storage quantity detected by the oxygen storage quantity detection means is equal to or more than a prescribed value, and the internal combustion engine is started, outputting a signal to burn fuel at an air/fuel ratio which is richer than a stoichiometric amount of air in a first period t<SB>0</SB>to t<SB>1</SB>from the start, and for outputting a signal to stop fuel injection in a second period t<SB>1</SB>to t<SB>2</SB>following the first period. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device for a hybrid vehicle using an internal combustion engine and an electric motor as drive sources.

In a hybrid vehicle that travels using the outputs of an internal combustion engine and an electric motor as a drive source, an engine in which the internal combustion engine is started by an electric motor has been proposed (Patent Document 1).

Further, in the hybrid vehicle, the piston operates without injecting fuel when the internal combustion engine is stopped or started, so that the oxygen storage amount of the catalyst provided in the exhaust system is increased, and the reducing power of the catalyst is increased. descend.

  In view of this, there has been proposed a method in which the reduction of nitrogen oxide purification efficiency is suppressed by reducing the amount of oxygen stored in the exhaust purification catalyst by reducing the amount of oxygen stored in the exhaust purification catalyst by starting a rich combustion from the start of the internal combustion engine (Patent Document). 2).

JP 2004-251221 A JP 2000-104588 A

  However, the hybrid vehicle burns with a rich air-fuel mixture at the start of the internal combustion engine, resulting in a wall flow larger than the equilibrium adhesion amount. When the internal combustion engine is stopped without changing the wall flow and the motor is changed to the motor running, and then the internal combustion engine is started again, there is a problem that the air-fuel mixture becomes rich due to the remaining wall flow.

  The problem to be solved by the present invention is to provide a control device for a hybrid vehicle that can prevent the enrichment at the start-up while suppressing a decrease in the purification efficiency of nitrogen oxides.

The present invention solves the above problem by burning the air-fuel ratio richer than stoichiometric for a predetermined period from the start of the internal combustion engine, and stopping fuel injection and closing the throttle valve for the subsequent predetermined period.

  According to the present invention, the richer combustion from the start of the internal combustion engine reduces the oxygen storage amount of the exhaust purification catalyst and increases the reducing power, so that it is possible to suppress a reduction in the purification efficiency of nitrogen oxides. Further, by stopping the fuel injection in the subsequent predetermined period and closing the throttle valve, the wall flow due to the rich air-fuel mixture can be quickly vaporized.

1 is a block diagram showing a hybrid vehicle according to an embodiment of the invention. It is a block diagram which shows the internal combustion engine of FIG. It is a flowchart which shows the main control procedures of the control apparatus of FIG. It is a time chart which shows the change of each element in the control procedure of FIG. 4 is a graph showing the relationship between the oxygen storage amount of the exhaust purification catalyst and the fuel injection stop time in step S4 of FIG. It is a graph which shows the relationship between the fuel increase in step S9 of FIG. 3, and fuel injection stop timing. It is a graph which shows the relationship between the wall flow volume in step S12 of FIG. 3, and fuel injection resumption timing.

  Hereinafter, a control device according to an embodiment of the invention will be described with reference to the drawings.

  The control apparatus 1 of this embodiment is applied to the rear-wheel drive hybrid vehicle HEV shown in FIG. 1, and the configuration of the drive system will be described. The drive system of the hybrid vehicle HEV shown in the figure includes an engine EG, a first clutch CL1, a motor generator (electric motor / generator) MG, a second clutch CL2, an automatic transmission AT, a propeller shaft PS, A differential gear unit DF, a drive shaft DS, and left and right drive wheels RR are provided. FL and FR are the left and right steering front wheels.

  The engine EG is an internal combustion engine that operates using gasoline or light oil as fuel, and based on a control signal from the engine controller 11, the valve opening of the throttle valve, the fuel injection amount, and the like are controlled. The detailed structure of the engine EG will be described later.

  The first clutch CL1 is a clutch interposed between the output shaft of the engine EG and the output shaft of the motor generator MG. For example, a wet multi-plate clutch capable of continuously controlling the oil flow rate and hydraulic pressure with a proportional solenoid is used. be able to. Then, the hydraulic pressure of the hydraulic unit is controlled based on a control signal from the control device 1, thereby controlling the engagement and release including slip engagement of the clutch plate.

  The motor generator MG is a synchronous motor generator in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator. The motor generator MG is driven by applying a three-phase alternating current generated by an inverter INV, and is controlled by a motor controller 31. The drive is controlled based on the signal.

  The motor generator MG can operate as an electric motor that is driven to rotate by receiving electric power supplied from the battery BAT (power running). When the rotor is rotated by an external force, an electromotive force is applied to both ends of the stator coil. It is also possible to charge the battery BAT by functioning as a generator that generates (regeneration).

  Note that the rotor of the motor generator MG is connected to the input shaft of the automatic transmission AT via a damper (not shown).

  The second clutch CL2 is a clutch interposed between the motor generator MG and the left and right drive wheels RL, RR. For example, a wet multi-plate clutch capable of continuously controlling the oil flow rate and hydraulic pressure with a proportional solenoid is used. Can do. The hydraulic pressure of the hydraulic unit is controlled based on a control signal from the control device 1, thereby controlling the engagement and release including slip engagement and slip release of the clutch plate.

  The automatic transmission AT is a transmission or a continuously variable transmission that automatically switches stepped gear ratios such as forward five speeds and reverse first speeds according to vehicle speed, accelerator opening, and the like. The switching operation is controlled by the signal. The second clutch CL2 can be provided as a dedicated clutch, but instead of this, some of the frictional engagement elements that are engaged at each gear stage of the automatic transmission AT are used. You can also

  The output shaft of the automatic transmission AT is connected to the left and right drive wheels RL and RR via a propeller shaft PS, a differential gear unit DF, and left and right drive shafts DS.

  The hybrid vehicle HEV of this example has three travel modes according to the engagement and disengagement state of the first clutch CL1.

  The first traveling mode is a case where the first clutch CL1 is in a released state, and is a motor-using traveling mode in which traveling is performed using only the power of the motor generator MG as a power source.

  The second travel mode is a case where the first clutch CL1 is in the engaged state, and is an engine use travel mode in which the vehicle travels while including the engine EG as a power source.

  The third travel mode is a case where the first clutch CL1 is engaged and the second clutch CL2 is slip-controlled, and is an engine-use slip travel mode in which the vehicle travels while including the engine EG as a power source. This mode is a mode for achieving creep running particularly when the state of charge (SOC) of the battery BAT is low or when the engine water temperature is low. Furthermore, it is also a mode in which the driving force can be output while starting the engine when starting from the engine stopped state.

  Hereinafter, the first travel mode is also referred to as EV travel mode, the second travel mode is also referred to as HEV travel mode, and the third travel mode is also referred to as WSC (Wet Start Clutch) travel mode.

  The HEV travel mode, which is the second travel mode, further includes three travel modes: an engine travel mode, a motor assist travel mode, and a travel power generation mode.

  The engine travel mode is a mode in which the motor generator MG moves the drive wheels RR and RL using only the engine EG as a power source without performing drive control.

  The motor assist travel mode is a mode in which both the engine EG and the motor generator MG are driven and controlled, and the drive wheels RR and RL are moved using these two as power sources.

  The traveling power generation mode is a mode in which the motor generator MG functions as a generator and charges the battery BAT at the same time as the driving wheels RR and RL are moved by controlling the engine EG as a power source.

  In addition to these modes, there may be provided a power generation mode in which the motor generator MG is operated as a generator using the power of the engine EG when the vehicle is stopped to charge the battery BAT or supply power to the electrical components. it can.

  Next, a configuration example of the engine EG will be described.

  FIG. 2 is a block diagram showing an engine EG according to this example. An air filter 112, an air flow meter 113 for detecting the intake air flow rate, a throttle valve 114 for controlling the intake air flow rate, A collector 115 is provided.

  The throttle valve 114 is provided with an actuator 116 such as a DC motor that adjusts the opening of the throttle valve 114. The throttle valve actuator 116 electronically controls the opening of the throttle valve 114 based on the drive signal from the engine control unit 11 so as to achieve the required torque calculated based on the driver's accelerator pedal operation amount and the like. Further, a throttle sensor 117 for detecting the opening degree of the throttle valve 114 is provided, and the detection signal is output to the engine control unit 1. The throttle sensor 117 can also function as an idle switch.

  A fuel injection valve 118 is provided so as to face the intake passage 111a branched from the collector 115 to each cylinder. The fuel injection valve 118 is driven to open by a drive pulse signal set in the engine control unit 11, and feeds fuel that is pumped from a fuel pump (not shown) and controlled to a predetermined pressure by a pressure regulator (hereinafter referred to as fuel injection valve). (Also referred to as a port) 111a.

  A space surrounded by the cylinder 119, the crown surface of the piston 120 that reciprocates within the cylinder, and the cylinder head provided with the intake valve 121 and the exhaust valve 122 constitutes a combustion chamber 123. The spark plug 124 is mounted facing the combustion chamber 123 of each cylinder, and ignites the intake air-fuel mixture based on an ignition signal from the engine control unit 11.

  On the other hand, the exhaust passage 125 is provided with an air-fuel ratio sensor 126 for detecting an exhaust gas by detecting a specific component in the exhaust gas, for example, oxygen concentration, and thus an air-fuel ratio of the intake air-fuel mixture. Is output. The air-fuel ratio sensor 126 may be an oxygen sensor that performs rich / lean output, or a wide-area air-fuel ratio sensor that linearly detects the air-fuel ratio over a wide area.

  The exhaust passage 125 is provided with an exhaust purification catalyst 127 for purifying the exhaust. The exhaust purification catalyst 127 oxidizes carbon monoxide CO and hydrocarbon HC in the exhaust in the vicinity of stoichiometric (theoretical air-fuel ratio, λ = 1, air weight / fuel weight = 14.7), and nitrogen oxide NOx. It is possible to use a three-way catalyst that can purify the exhaust gas by reducing the above, or an oxidation catalyst that oxidizes carbon monoxide CO and hydrocarbon HC in the exhaust gas.

  On the downstream side of the exhaust purification catalyst 127 in the exhaust passage 125, there is provided an oxygen sensor 128 that detects a specific component in the exhaust, for example, oxygen concentration, and outputs a rich / lean output, and the detection signal is output to the engine control unit 11. The Here, by correcting the air-fuel ratio feedback control based on the detection value of the air-fuel ratio sensor 126 based on the detection value of the oxygen sensor 128, so as to suppress a control error associated with the deterioration of the air-fuel ratio sensor 126 (so-called) Although the downstream oxygen sensor 128 is provided (for the adoption of a double air-fuel ratio sensor system), if it is only necessary to perform air-fuel ratio feedback control based on the detection value of the air-fuel ratio sensor 126, the oxygen sensor 128 is Can be omitted.

  In FIG. 1, reference numeral 129 denotes a muffler.

  The crankshaft 130 of the engine EG is provided with a crank angle sensor 131, and the engine control unit 11 counts a crank unit angle signal output from the crank angle sensor 131 in synchronization with the engine rotation for a predetermined time, or By measuring the cycle of the crank reference angle signal, the engine speed Ne can be detected.

  The cooling jacket 132 of the engine EG is provided with a water temperature sensor 133 facing the cooling jacket, detects the cooling water temperature Tw in the cooling jacket 131, and outputs this to the engine control unit 11.

  Returning to FIG. 1, the control system of the hybrid vehicle HEV of this example includes a control device 1, an engine controller 11, a motor controller 31, and a transmission controller 51, as shown in the figure. The control device 1, the engine controller 11, the motor controller 31, and the transmission controller 51 can be connected via, for example, a CAN communication line capable of exchanging information.

  The engine controller 11 inputs the engine water temperature from the engine water temperature sensor 133, the intake air amount from the air flow meter 113, the throttle opening from the throttle opening sensor 116a, and the engine rotational speed Ne information from the crank angle sensor 131, and performs control. A command for controlling the engine operating point (engine speed Ne, engine torque Te) is output to the throttle valve actuator 116 in accordance with a target engine torque command or the like from the device 1. The throttle valve actuator 116 adjusts the opening of the throttle valve 114 in accordance with a command from the engine controller 11.

  Further, the engine controller 11 estimates the engine torque Te based on the fuel injection amount of the engine EG, the throttle opening degree, and the like. Information on the engine speed Ne and the estimated engine torque Te is sent to the control device 1 via the CAN communication line.

  The motor controller 2 inputs information from a resolver that detects the rotor rotational position of the motor generator MG, and in response to a target motor generator torque command from the control device 1, the motor operating point of the motor generator MG (motor rotational speed Nm, A command for controlling the motor torque Tm) is output to the inverter INV. The motor controller 31 monitors the battery SOC indicating the state of charge of the battery BAT, and the battery SOC information is used as control information for the motor generator MG and is sent to the control device 1 via the CAN communication line. Is done.

  Further, the motor controller 31 estimates the motor generator torque Tm based on the value of the current flowing through the motor generator MG (the driving torque and the regenerative braking torque are distinguished based on whether the current value is positive or negative), and the estimated motor generator torque The Tm information is sent to the control device 1 via the CAN communication line.

  The control device 1 inputs sensor information from a hydraulic pressure sensor and a stroke sensor provided in the first clutch CL1, and in response to the first clutch control command, a first command for controlling the engagement / release of the first clutch CL1 is provided. Output to the hydraulic unit of the clutch CL1.

The AT controller 51 inputs sensor information from the accelerator opening sensor 71, the vehicle speed sensor 72, and the hydraulic pressure sensor of the second clutch CL2, and engages the second clutch CL2 according to the second clutch control command from the control device 1. A command for controlling release is output to the hydraulic unit of the second clutch CL2. Information on the accelerator pedal opening APO and the vehicle speed VSP is input to the control device 1.

  Although not shown, the brake controller inputs wheel speed sensors for detecting the wheel speeds of the four wheels and sensor information from the brake stroke sensor. For example, the required braking force obtained from the brake stroke BS at the time of brake depression braking. On the other hand, when the regenerative braking force alone is insufficient, the regenerative cooperative brake control is performed based on the regenerative cooperative control command from the control device 1 so that the shortage is compensated by the friction braking force.

The control device 1 manages the energy consumption of the entire vehicle and has a function for running the vehicle with the highest efficiency. The control device 1 detects the motor rotation speed Nm, and the output rotation speed of the second clutch CL2. A second clutch output rotational speed sensor for detecting N2out, a second clutch torque sensor for detecting torque TCL2 of the second clutch CL2, a brake hydraulic pressure sensor, a temperature sensor for detecting the temperature of the first clutch CL1, and a second Information from the temperature sensor that detects the temperature of the clutch CL2 and information obtained through the CAN communication line are input.

The motor rotation speed sensor is equivalent to the input shaft rotation speed sensor of the automatic transmission AT. The second clutch output rotational speed sensor is a sensor that detects the output shaft rotational speed of the automatic transmission AT and calculates the output rotational speed of the second clutch CL2 based on the relationship between the respective engagement elements. This is equivalent to the output shaft rotational speed sensor of the transmission AT.

  Further, the control device 1 controls the operation of the engine EG based on the control command to the engine controller 11, the operation control of the motor generator MG based on the control command to the motor controller 31, and the automatic transmission of the automatic transmission based on the control command to the AT controller 51. Operation control, engagement / release control of the first clutch CL1 by a control command to the hydraulic unit of the first clutch CL1, and engagement / release control of the second clutch CL2 by a control command to the hydraulic unit of the second clutch CL2 Do.

  Now, in the hybrid vehicle described above, when the engine EG is stopped and the vehicle is switched to the EV traveling mode in which only the motor generator MG is driven as a driving source, or when the stopped engine EG is started by the driving force of the motor generator MG, the fuel is supplied. When the piston operates without injecting, the amount of oxygen stored in the exhaust purification catalyst 127 provided in the exhaust passage 125 increases and the reducing power decreases. Since the purification efficiency of nitrogen oxides NOx decreases when the reducing power decreases, in this example, the following control is executed in a situation where the oxygen storage amount of the exhaust purification catalyst 127 increases.

  FIG. 3 is a flowchart showing the control procedure of the control device 1. A case where a restart request signal is input from a state where the engine EG has stopped will be described.

  First, when a restart request signal is input in such a state where the engine EG is stopped, it is determined in steps S1 to S3 whether the control in steps S4 to S12 or the control in step S14 is executed.

That is, it is determined whether or not the water temperature Tw detected by the water temperature sensor 133 is in a warm-up state of a predetermined value or more (step S1), and it is confirmed that the exhaust purification catalyst 127 is activated. When the water temperature Tw is not in the warm-up state of the predetermined value or more and the exhaust purification device 127 is not activated, the process proceeds to step S14 and the control for activating the exhaust purification catalyst 127 is executed.

In step S2, it is determined whether or not the charge amount SOC of the battery BAT is equal to or greater than a predetermined value. If the charge amount SOC is insufficient, the motor generator MG cannot be started, and the process proceeds to step S14.

In step S3, it is determined whether or not the oxygen storage amount OSC of the exhaust purification catalyst 127 is equal to or greater than the target OSC amount. If the oxygen storage amount OSC is less than the target OSC amount, the oxidizing power is low and the process proceeds to step S14.

  In steps S1 to S3, the exhaust purification catalyst 127 is in a warm-up state, the charge amount of the battery BAT is a charge amount sufficient for restart, and the oxygen storage amount of the exhaust purification catalyst 127 is rich. If it is determined that the state has sufficient oxidizing power, the process proceeds to step S4.

In step S4, the operation and the target oxygen storage amount of the exhaust purification catalyst 127, the difference in the oxygen storage amount OSC of t ₀ when the engine start request is made, the fuel required to release the oxygen storage amount of the difference The total amount of increase ΔV is calculated. That is, when oxygen larger than the target oxygen storage amount is stored in the exhaust purification catalyst 127, when the engine EG is started, it is burned at a richer air-fuel ratio than stoichiometric, and the hydrocarbon HC and carbon monoxide CO are oxidized. Then, the oxygen storage amount of the exhaust purification catalyst 127 that is excessive is adjusted.

The target oxygen storage amount is a value determined in advance by the balance between the oxidizing power and the reducing power of the exhaust purification catalyst 127, and is the target oxygen storage amount in the fuel injection process in step S7. As shown in FIG. 5, the target oxygen storage amount can be set smaller than the optimal oxygen storage amount with which the conversion efficiency of the catalyst is optimal.

Further, the oxygen storage amount of the exhaust purification catalyst 127 at t ₀ can be estimated by calculation from the oxygen concentration detected by the air-fuel ratio sensor 126 or the oxygen sensor 128.

In step S5, the fuel split ratio of the increase ΔV calculated in step S4 is calculated, and the air-fuel ratio and injection time for injection are obtained. In the subsequent step S6, the first clutch CL1 is engaged, the engine EG is started by the driving force of the motor generator MG, and fuel injection is started in step S7.

Here, in the calculation of the split ratio in step S5, the fuel increase amount ΔV corresponding to the oxygen storage amount of the exhaust purification catalyst 127 obtained in step S4 is used, for example, with the rich combustible limit equivalent ratio as the target air-fuel ratio λ. Inject, or inject fuel with a target air-fuel ratio λ that is leaner but richer than stoichiometric, or gradually approach stoichiometric from the equivalent ratio of the rich flammability limit according to the demands of drivability Fuel can be injected at an air-fuel ratio. These states are shown in FIG.

(I) shows the case of fuel injection at the richest flammable limit air-fuel ratio, (ii) shows the case of fuel injection at a leaner air-fuel ratio, and (iii) shows the flammable limit air-fuel ratio. The case where fuel injection is performed while the air-fuel ratio is gradually changed from the fuel ratio toward the stoichiometric state is shown. In any case, the area that is the integrated value of fuel injection corresponds to the amount of fuel increase ΔV corresponding to the oxygen storage amount obtained in step S4, whereby each fuel injection time t ₁ (i). , T ₁ (ii), t ₁ (iii).

In step S8, the difference between the fuel increase amount ΔV obtained in step S4 and the integrated value of the actually injected fuel becomes zero, that is, the area in FIG. 6 is equal to the fuel increase amount ΔV in step S4. made to continue fuel injection to the time t _1, the program proceeds to step S9 If becomes zero, to stop the fuel injection.

Engine speed, boost, fuel injection amount, intake passage wall flow rate, throttle opening, fuel air-fuel ratio, integrated value of piston idling cycle number, oxygen storage amount OSC amount, exhaust passage nitrogen until time t1 above The state of change of each element of oxide NOx emission will be described with reference to FIG.

When the stop request of the engine EG is made in time -t ₂ at the left end in the figure, closing the opening of the throttle valve 114 until idle opening with the fuel injection from the fuel injection valve 118 stops accordingly. Since the piston 120 is idled several times when the engine is stopped, the oxygen storage amount of the exhaust purification catalyst 127 becomes richer than that during operation of the engine EG.

When the engine EG is stopped at time -t ₁ in the figure, the boost pressure, which has been a negative pressure, is increased by closing the throttle valve and rotating the piston until then. As a result, the wall flow rate of the intake passage (fuel injection port) 111a also slightly decreases.

When a restart request for the engine EG is made at time t ₀ in the figure, the motor generator MG increases the engine EG rotation speed and opens the throttle valve 114 until time t ₁ as described above. Then, the fuel is injected from the fuel injection valve 118, the air-fuel mixture richer than stoichiometric is supplied to the combustion chamber 123, and combustion is started. As a result, the oxygen stored in the exhaust purification catalyst 127 is reduced to the target oxygen storage amount.

In step S8 in the time t ₁ and 3 in the figure, when finished the fuel injection increase amount ΔV of the fuel corresponding to the oxygen storage amount, with temporarily stopping fuel injection from the fuel injection valve 118 at step S9, The throttle valve 114 is closed. At this time, as shown in FIG. 4, the rotational speed of engine EG continues to increase with the assistance of motor generator MG.

Fuel cut from the time t ₁ to t _2, by continuing the closing operation and the engine speed of the throttle valve 114, an intake passage (fuel injection ports) 111a boost is reduced, thereby balancing deposited by rich mixture until it The fuel that has become a wall flow larger than the amount can be quickly vaporized. That is, during the period from time t ₀ to t ₁ , the boost is not sufficiently low, and the wall flow rate of the injection port 111a is larger than the equilibrium adhesion amount in order to burn the air-fuel mixture at low speed and richness. Vaporization of fuel can be promoted by the process of S9. The vaporized fuel (hydrocarbon) contributes to the reduction action of the exhaust purification catalyst 127.

In the next step S10, the required torque is calculated based on the output of the accelerator opening sensor 71, and the rotational speed and boost at the start of the engine EG are calculated.

In step S11, the target wall flow rate is calculated from the engine speed and boost obtained in step S10. Then, when the current wall flow rate becomes equal to the target wall flow rate in step S12, that is, at time t2, fuel injection is resumed (step S13). Thereby, the engine can be started in a state where the oxygen storage amount of the exhaust purification catalyst 127 is not excessive, and the emission amount of nitrogen oxides NOx can be suppressed. In addition, since the engine is started in a state where the boost is sufficiently low, combustion can be stabilized in a short time and with a minimum wall flow correction amount.

The wall flow vaporization amount determined from the time and temperature (using the water temperature sensor 133) when the engine EG was stopped is subtracted from the wall flow rate when the engine EG is stopped (time-t _{1 in} FIG. 4). Then, the wall flow rate at the time of restart request of the engine EG (time t _{0 in} FIG. 4) is obtained.

The wall flow rate during the time t _{0 to} t ₁ during which fuel is injected is calculated as the difference between the output of the air-fuel ratio sensor 126 and the fuel injection amount by the fuel injection valve 118 and the intake air amount by the air flow meter 113. It can ask for.

The wall flow rate during the time t _{1 to} t ₂ when the fuel injection is stopped can be obtained by using a map of the boost for each water temperature and the vaporization ratio, and the wall flow rate at the time of stopping the fuel injection = the previous wall flow rate × (1-wall flow vaporization ratio).

Then, the fuel injection is restarted from time t ₂ when the wall flow rate obtained as described above gradually approaches the equilibrium adhesion amount corresponding to the target rotational speed as shown in FIG.

Incidentally, (step S13 in FIG. 3) at an initial time _{t 2} in FIG. 4, in order to enhance the nitrogen oxides NOx purification efficiency of the exhaust gas purifying catalyst 127, further time _t 0 ~t control between ₁ (in FIG. 3 Steps S4 to S8) may be added.

Further, the fuel injection timing between the times t _{0 and} t ₁ in FIG. 4 may be an intake stroke in which the amount of wall flow adhesion is relatively small.

Moreover, in order to burn the wall-flow vaporized fuel between the times t _{1 and} t ₂ in FIG. 4, it is desirable to burn it for a predetermined cycle.

The control device 1 of the above-described embodiment corresponds to the control unit according to the present invention, the air-fuel ratio sensor 126 or the oxygen sensor 128 corresponds to the oxygen storage amount detection unit according to the present invention, and the time t _{0 to} t ₁ is the present invention. first corresponds to a period corresponds to a second period according to the time t ₁ ~t ₂ is the invention corresponds to the third time period according to the time t _{2 ~} is invention, the control device 1 is present according to the This corresponds to the wall flow rate estimating means according to the invention.

HEV ... Hybrid vehicle 1 ... Control device EG ... Engine (internal combustion engine)
DESCRIPTION OF SYMBOLS 11 ... Engine controller 111, 111a ... Intake passage 112 ... Air filter 113 ... Air flow meter 114 ... Throttle valve 115 ... Collector 116 ... Throttle valve actuator 117 ... Throttle sensor 118 ... Fuel injection valve 119 ... Cylinder 120 ... Piston 121 ... Intake valve 122 Exhaust valve 123 ... Combustion chamber 124 ... Spark plug 125 ... Exhaust passage 126 ... Air-fuel ratio sensor 127 ... Exhaust purification catalyst 128 ... Oxygen sensor 129 ... Muffler 130 ... Crankshaft 131 ... Crank angle sensor 132 ... Cooling jacket 133 ... Water temperature sensor MG ... motor generator 31 ... motor controller INV ... inverter BAT ... battery AT ... automatic transmission 51 ... transmission controller CL1 ... first clutch CL2 ... second clutch S ... propeller shaft DS ... drive shaft DF ... differential gear unit 71 ... accelerator opening sensor 72 ... vehicle speed sensor

Claims (7)

A control device that outputs a control signal to a hybrid vehicle including an internal combustion engine, an electric motor, and a wheel connected to the output shaft of the internal combustion engine or the electric motor,
Oxygen storage amount detection means for detecting the oxygen storage amount of an exhaust purification catalyst provided in the exhaust system of the internal combustion engine;
When the oxygen storage amount detected by the oxygen storage amount detection means is equal to or greater than a predetermined value and the internal combustion engine is started, a signal for burning at an air-fuel ratio richer than stoichiometry is output for the first period from the start of the start. And a control means for outputting a signal for stopping the fuel injection and closing the throttle valve during a second period following the first period. In the hybrid vehicle control device according to claim 1,
The control means includes
The hybrid vehicle control device outputs a signal for opening the throttle valve during the first period. In the hybrid vehicle control device according to claim 2,
The control means includes
In a third period following the second period, the hybrid vehicle control apparatus outputs a signal for setting the throttle valve to a target opening degree corresponding to a load and burning the stoichiometrically. In the hybrid vehicle control device according to claim 1,
The control means includes
Setting the fuel injection amount for the first period based on the difference between the target oxygen storage amount of the exhaust purification catalyst and the oxygen storage amount detected by the oxygen storage amount detection means at the start of the start. A hybrid vehicle control device. The hybrid vehicle control device according to claim 4,
The control means includes
The hybrid vehicle outputs a stop signal for fuel injection in the second period when the difference between the set fuel injection amount and the integrated value of the actually injected fuel becomes zero. Control device. In the hybrid vehicle control device according to claim 3,
A wall flow rate estimating means for estimating the wall flow rate of the fuel injection port based on the temperature and pressure of the intake system;
The control means includes
When the wall flow rate of the fuel injection port estimated by the wall flow rate estimation means becomes equal to the target wall flow rate corresponding to the required load, a signal for burning with the stoichiometric period of the third period is output. A control device for a hybrid vehicle. In the control apparatus of the hybrid vehicle as described in any one of Claims 1-6,
The hybrid vehicle includes an internal combustion engine having an output shaft, an electric motor having an output shaft coupled to the output shaft, wheels connected to the output shaft of the electric motor, an output shaft of the internal combustion engine, and an output of the electric motor. A hybrid vehicle control device comprising: a first clutch for connecting / disconnecting power transmission to / from a shaft; and a second clutch for connecting / disconnecting power transmission between an output shaft of the motor and a wheel.

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