Control device for internal combustion engine

Abstract

To suppress the deterioration of exhaust emission.SOLUTION: A control device of an internal combustion engine can perform feedback control for feedback-controlling the internal combustion engine so that a detection air-fuel ratio detected by an air-fuel ratio sensor reaches a prescribed air-fuel ratio for enriching an air-fuel ratio at an upstream side more than a theoretical air-fuel ratio, or feedforward control for feedforward-controlling the internal combustion engine so that a fuel injection amount is increased by a prescribed amount more than an injection amount corresponding to the theoretical air-fuel ratio. After a start of the internal combustion engine which is intermittently stopped, when the feedback control is executable, the control device performs the feedback control without performing the feedforward control, and when the feedback control is not executable, the control device performs the feedforward control without performing the feedback control.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a control device for an internal combustion engine, and more particularly to a control device for controlling the internal combustion engine of an internal combustion engine system including an internal combustion engine, a purification catalyst, and an air-fuel ratio sensor. [Background technology]

[0002] Conventionally, as a control device for this type of internal combustion engine, one that controls an internal combustion engine of an internal combustion engine device that includes an internal combustion engine, a purification catalyst, and first and second air-fuel ratio sensors (upstream and downstream air-fuel ratio sensors) has been proposed (see, for example, Patent Document 1). The purification catalyst is attached to an exhaust system and purifies exhaust gas from the internal combustion engine. The first air-fuel ratio sensor detects an air-fuel ratio upstream of the purification catalyst in the exhaust system. The second air-fuel ratio sensor detects an air-fuel ratio downstream of the purification catalyst in the exhaust system. In this device, after starting the internal combustion engine that is intermittently stopped, the device sets the rich side value of the target air-fuel ratio for enriching the upstream air-fuel ratio based on the downstream air-fuel ratio detected by the second air-fuel ratio sensor as the control target air-fuel ratio, and the target air-fuel ratio that is set at predetermined time intervals. Then, the internal combustion engine is controlled so that the upstream air-fuel ratio detected by the first air-fuel ratio sensor becomes the control target air-fuel ratio. This enriches the catalyst atmosphere, which has become lean due to the intermittent stop, reducing the amount of oxygen stored in the purification catalyst, and suppresses the deterioration of the purification performance of the purification catalyst after the intermittent stop (after fuel injection is resumed). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-115620 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned control device for an internal combustion engine, the richer value of the provisional target air-fuel ratio and the target air-fuel ratio is set as the control target air-fuel ratio, so the fuel injection amount is likely to be excessive. As a result, unburned fuel may be adsorbed to the purification catalyst, or in some cases, unburned fuel may be discharged into the atmosphere, causing emissions to worsen.

[0005] The main object of the internal combustion engine control device of the present invention is to suppress the deterioration of emissions. [Means for solving the problem]

[0006] The internal combustion engine control device of the present invention employs the following means to achieve the above-mentioned main object.

[0007] The control device for an internal combustion engine of the present invention comprises: An internal combustion engine; a purification catalyst attached to an exhaust system of the internal combustion engine and purifying exhaust gas from the internal combustion engine; an air-fuel ratio sensor for detecting an air-fuel ratio upstream of the purification catalyst in the exhaust system; A control device for controlling an internal combustion engine of an internal combustion engine apparatus comprising: a feedback control for feedback controlling the internal combustion engine so that the detected air-fuel ratio detected by the air-fuel ratio sensor becomes a predetermined air-fuel ratio for making the upstream air-fuel ratio richer than the stoichiometric air-fuel ratio, or a feedforward control for feedforward controlling the internal combustion engine so that the fuel injection amount is increased by a predetermined amount from the injection amount corresponding to the stoichiometric air-fuel ratio, After the internal combustion engine that has been intermittently stopped is started, when the feedback control is executable, the feedback control is executed without executing the feedforward control, and when the feedback control is not executable, the feedforward control is executed without executing the feedback control. The gist of the present invention is as follows.

[0008] In the control device for an internal combustion engine according to the present invention, either feedback control for feedback-controlling the internal combustion engine so that the detected air-fuel ratio detected by the air-fuel ratio sensor becomes a predetermined air-fuel ratio for making the upstream air-fuel ratio richer than the stoichiometric air-fuel ratio, or feedforward control for feedforward-controlling the internal combustion engine so that the fuel injection amount is increased by a predetermined amount from the injection amount corresponding to the stoichiometric air-fuel ratio, can be executed. When the feedback control is executable after the start of the internal combustion engine that is intermittently stopped, the feedback control is executed without executing the feedforward control. If the fuel injection amount is increased by a predetermined amount as in the feedforward control, the fuel injection amount may become excessive depending on the length of the intermittent stop period, and the emission may deteriorate. In the present invention, when the feedback control is executable after the start of the internal combustion engine that is intermittently stopped, the feedback control is executed without executing the feedforward control, thereby preventing the fuel injection amount from becoming excessive and preventing the emission from worsening. And when the feedback control is not executable after the start of the internal combustion engine that is intermittently stopped, the feedforward control is executed without executing the feedback control. As a result, even when feedback control is not possible, the air-fuel ratio on the upstream side of the purification catalyst can be made richer than the stoichiometric air-fuel ratio, and deterioration of emissions can be suppressed. As a result, deterioration of emissions can be suppressed. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram showing an outline of the configuration of a hybrid vehicle 20 equipped with an engine device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing an outline of the configuration of an engine 22. [Diagram 3] 4 is a flowchart showing an example of a post-start control routine executed by an engine ECU 24. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Next, a mode for carrying out the present invention will be described using examples. EXAMPLES

[0011] Fig. 1 is a schematic diagram showing the configuration of a hybrid vehicle 20 equipped with an internal combustion engine control device as an embodiment of the present invention. Fig. 2 is a schematic diagram showing the configuration of an engine 22. As shown in Fig. 1, the hybrid vehicle 20 of the embodiment includes the engine 22, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, a battery 50, and a hybrid electronic control unit (hereinafter referred to as "HVECU") 70.

[0012] The engine 22 is configured as an internal combustion engine that outputs power using gasoline, diesel, or the like as fuel. As shown in FIG. 2, the engine 22 draws air purified by an air cleaner 122 into an intake pipe 123, passes the air through a throttle valve 124 and a surge tank 125, and injects fuel from a fuel injection valve 126 downstream of the surge tank 125 of the intake pipe 123 to mix the air and fuel. The engine 22 then draws the mixture into a combustion chamber 129 via an intake valve 128, and explosively burns the intake mixture with an electric spark from an ignition plug 130. The reciprocating motion of a piston 132 pushed down by the energy of this explosive combustion is converted into the rotational motion of the crankshaft 26. Exhaust exhaust discharged from the combustion chamber 129 into an exhaust pipe 134 via an exhaust valve 133 is discharged into the outside air via purification devices 136, 138. The purifying devices 136, 138 each have a purification catalyst (three-way catalyst) 136a, 138a that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) in the exhaust gas. The purification catalysts 136a, 138a are each configured to be capable of storing oxygen.

[0013] The operation of the engine 22 is controlled by an engine electronic control unit (hereinafter referred to as "engine ECU") 24. Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU, and in addition to the CPU, includes a ROM for storing processing programs, a RAM for temporarily storing data, an input / output port, and a communication port.

[0014] Signals from various sensors required for controlling the operation of the engine 22 are input to the engine ECU 24 via an input port. Examples of signals input to the engine ECU 24 include a crank angle θcr from a crank position sensor 140 that detects the rotational position of the crankshaft 26 of the engine 22, and a coolant temperature Tw from a water temperature sensor 142 that detects the temperature of the coolant for the engine 22. Other examples include a cam position θca from a cam position sensor 144 that detects the rotational positions of an intake camshaft that opens and closes the intake valve 128 and an exhaust camshaft that opens and closes the exhaust valve 133. Other examples include a throttle opening TH from a throttle valve position sensor 124a that detects the position of the throttle valve 124, an intake air amount Qa from an air flow meter 148 attached to the intake pipe 123, an intake air temperature Ta from a temperature sensor 149 attached to the intake pipe 123, and a surge pressure Ps from a pressure sensor 150 attached to the surge tank 125. In addition, examples of the detected air-fuel ratio AFu include the detected air-fuel ratio AFu from an upstream air-fuel ratio sensor 152 attached upstream of the purification device 136 in the exhaust pipe 134, and the detected air-fuel ratio AFd from a downstream air-fuel ratio sensor 154 attached downstream of the purification device 136 in the exhaust pipe 134 and upstream of the purification device 138.

[0015] From the engine ECU 24, various control signals for controlling the operation of the engine 22 are output via an output port. Examples of signals output from the engine ECU 24 include a drive control signal to a throttle motor 124b that adjusts the position of the throttle valve 124, a drive control signal to a fuel injector 126, and a control signal to an ignition plug 130.

[0016] The engine ECU 24 is connected to the HVECU 70 via a communication port. The engine ECU 24 calculates the rotation speed Ne of the engine 22 based on the crank angle θcr of the engine 22 from the crank position sensor 140. The engine ECU 24 also calculates a volumetric efficiency KL (the ratio of the volume of air actually taken in one cycle to the stroke volume per cycle of the engine 22) based on the intake air amount Qa from the air flow meter 148 and the rotation speed Ne of the engine 22.

[0017] As shown in Fig. 1, the planetary gear 30 is configured as a single pinion type planetary gear mechanism. A rotor of a motor MG1 is connected to a sun gear of the planetary gear 30. A drive shaft 36 that is connected to drive wheels 39a, 39b via a differential gear 38 is connected to a ring gear of the planetary gear 30. A crankshaft 26 of the engine 22 is connected to a carrier of the planetary gear 30 via a damper 28.

[0018] The motor MG1 is configured, for example, as a synchronous generator motor, and as described above, its rotor is connected to the sun gear of the planetary gear 30. The motor MG2 is configured, for example, as a synchronous generator motor, and its rotor is connected to the drive shaft 36. The inverters 41, 42 are used to drive the motors MG1, MG2, and are connected to a battery 50 via a power line 54. The motors MG1, MG2 are rotationally driven by a motor electronic control unit (hereinafter referred to as "motor ECU") 40 controlling the switching of a plurality of switching elements (not shown) of the inverters 41, 42.

[0019] Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU, and in addition to the CPU, includes a ROM for storing processing programs, a RAM for temporarily storing data, an input / output port, and a communication port. Signals from various sensors required for driving and controlling the motors MG1 and MG2 are input to the motor ECU 40 via the input port. Examples of signals input to the motor ECU 40 include the rotational positions θm1 and θm2 of the rotors of the motors MG1 and MG2 from rotational position sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and the phase currents Iu1, Iv1, Iu2, and Iv2 of the motors MG1 and MG2 from current sensors that detect the phase currents flowing through the phases of the motors MG1 and MG2. The motor ECU 40 outputs switching control signals to a plurality of switching elements (not shown) of the inverters 41 and 42 via an output port. The motor ECU 40 is connected to the HVECU 70 via a communication port. The motor ECU 40 calculates the electrical angles θe1, θe2 and rotation speeds Nm1, Nm2 of the motors MG1, MG2 based on the rotational positions θm1, θm2 of the rotors of the motors MG1, MG2 from the rotational position sensors 43, .

[0020] The battery 50 is configured as, for example, a lithium ion secondary battery or a nickel-hydrogen secondary battery, and as described above, is connected to the inverters 41, 42 via the power line 54. The battery 50 is managed by a battery electronic control unit (hereinafter referred to as the "battery ECU") 52.

[0021] Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU, and in addition to the CPU, includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port. Signals from various sensors required for managing the battery 50 are input to the battery ECU 52 via an input port. Examples of signals input to the battery ECU 52 include the voltage Vb of the battery 50 from a voltage sensor 51a attached between the terminals of the battery 50, the battery current Ib of the battery 50 from a current sensor 51b attached to the output terminal of the battery 50, and the temperature Tb of the battery 50 from a temperature sensor 51c attached to the battery 50. The battery ECU 52 is connected to the HVECU 70 via a communication port. The battery ECU 52 calculates a power storage ratio SOC based on an integrated value of the battery current Ib from the current sensor 51b. The power storage ratio SOC is a ratio of the capacity of the power that can be discharged from the battery 50 to the total capacity of the battery 50.

[0022] Although not shown, the HVECU 70 is configured as a microprocessor centered on a CPU, and in addition to the CPU, includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port. Signals from various sensors are input to the HVECU 70 via the input port. Examples of signals input to the HVECU 70 include an ignition signal from an ignition switch 80 and a shift position SP from a shift position sensor 82 that detects the operation position of a shift lever 81. Other examples of signals input to the HVECU 70 include an accelerator opening Acc from an accelerator pedal position sensor 84 that detects the amount of depression of an accelerator pedal 83, a brake pedal position BP from a brake pedal position sensor 86 that detects the amount of depression of a brake pedal 85, a vehicle speed V from a vehicle speed sensor 88, and an outside air temperature Tout from an outside air temperature sensor 89. As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port.

[0023] The hybrid vehicle 20 of the embodiment thus configured runs in an electric drive mode (EV drive mode) in which it runs without the operation of the engine 22, or in a hybrid drive mode (HV drive mode) in which it runs with the operation of the engine 22.

[0024] In the EV driving mode, the HVECU 70 first sets a required torque Td* required for driving (required of the drive shaft 36) based on the accelerator opening Acc and the vehicle speed V. Next, the HVECU 70 sets a value of 0 to the torque command Tm1* of the motor MG1, and sets a torque command Tm2* of the motor MG2 so that the required torque Td* is output to the drive shaft 36, and transmits the set torque commands Tm1*, Tm2* of the motors MG1, MG2 to the motor ECU 40. The motor ECU 40 performs switching control of multiple switching elements of the inverters 41, 42 so that the motors MG1, MG2 are driven by the torque commands Tm1*, Tm2*.

[0025] In this EV driving mode, when the required power Pd* required for driving, obtained by multiplying the required torque Td* by the rotation speed Nd of the drive shaft 36, reaches or exceeds a threshold Pref, the engine 22 is started and the mode transitions to the HV driving mode. The engine 22 is started by motoring the motor MG1 to increase the rotation speed Ne of the engine 22, and when the rotation speed Ne of the engine 22 reaches or exceeds a predetermined rotation speed Nst (e.g., 800 rpm, 900 rpm, 1000 rpm, etc.), intake air amount control, fuel injection control, ignition control, etc. of the engine 22 are initiated.

[0026] In the HV driving mode, the HVECU 70 first sets the required torque Td* in the same manner as in the EV driving mode. Next, the required torque Td* is multiplied by the rotation speed Nd of the drive shaft 36 to calculate the required power Pd* required for driving, and the required power Pe* required for the engine 22 is calculated by subtracting the charge / discharge required power Pb* (a positive value when discharging from the battery 50) of the battery 50 from the required power Pd*. Here, as the rotation speed Nd of the drive shaft 36, for example, the rotation speed Nm2 of the motor MG2 or a rotation speed obtained by multiplying the vehicle speed V by a conversion coefficient is used. Then, the target speed Ne* and target torque Te* of the engine 22 and torque commands Tm1* and Tm2* of the motors MG1 and MG2 are set so that the required power Pe* is output from the engine 22 and the required torque Td* is output to the drive shaft 36, and the target speed Ne* and target torque Te* of the engine 22 are transmitted to the motor ECU 24, and the torque commands Tm1* and Tm2* of the motors MG1 and MG2 are transmitted to the motor ECU 24. The engine ECU 24 performs intake air amount control, fuel injection control, ignition control, etc. of the engine 22 so that the engine 22 is operated based on the target speed Ne* and target torque Te*. The control of the motors MG1 and MG2 (inverters 41 and 42) by the motor ECU 40 has been described above.

[0027] In the HV driving mode, when the required power Pd* falls below the stop threshold Pstop, the operation of the engine 22 is stopped (intermittently stopped) and the mode transitions to the EV driving mode. The operation of the engine 22 is stopped by stopping the intake air amount control, fuel injection control, ignition control, etc. of the engine 22 and motoring the motor MG1 so that the rotation speed Ne of the engine 22 decreases.

[0028] Next, the operation of the hybrid vehicle 20 of the embodiment thus configured will be described, in particular the fuel injection operation immediately after starting the engine 22 that has been stopped (intermittently stopped) (after intake air volume control, fuel injection control, ignition control, etc. of the engine 22 have begun).

[0029] In the post-start fuel injection control, the engine ECU 24 executes post-start feedback control or post-start feedforward control. The post-start fuel injection control will be described in detail below. Fig. 3 is a flowchart showing an example of a post-start control routine executed by the engine ECU 24. This routine is executed immediately after the engine 22, which has been stopped (intermittently stopped) by the above-mentioned start process of the engine 22, is started (immediately after intake air amount control, fuel injection control, ignition control, etc. of the engine 22 are started).

[0030] When this routine is executed, the CPU (not shown) of the engine ECU 24 executes a process to determine whether or not the post-start feedback control is executable (step S100). The post-start feedback control sets a target intake air amount Ga* based on the target torque Te* from the HVECU 70, and sets a target injection amount Qf* based on the target intake air amount Ga* and the target air-fuel ratio AF* set to the detected air-fuel ratio AFu from the upstream air-fuel ratio sensor 152 and the rich-side air-fuel ratio AFr (for example, 13.5) higher than the stoichiometric air-fuel ratio, so that the detected air-fuel ratio AFu detected by the upstream air-fuel ratio sensor 152 becomes the target air-fuel ratio AF*. Then, the fuel injection valve 126 is controlled so that fuel injection of the target injection amount Qf* is performed. That is, in the post-start feedback control, the engine 22 is feedback-controlled so that the difference between the target air-fuel ratio AF* and the detected air-fuel ratio AFu (rich-side air-fuel ratio AFr) becomes small. The rich-side air-fuel ratio AFr is determined in advance through experiments, analysis, etc., as an air-fuel ratio that can enrich the catalytic atmosphere of the purification catalysts 136a, 138a that have become lean due to the intermittent stopping of the engine 22 while suppressing the deterioration of emissions, reduce the oxygen storage amount of the purification catalysts 136a, 138a, and suppress the deterioration of purification performance. In the judgment of step S100, a time when the feedback control after starting can be executed can be exemplified by a time when the upstream air-fuel ratio sensor 152 is normal and the detected air-fuel ratio AFu from the upstream air-fuel ratio sensor 152 is input to the engine ECU 24 via a connection line (not shown). A time when the feedback control after starting cannot be executed can be exemplified by a time when an abnormality occurs in the upstream air-fuel ratio sensor 152, or when the upstream air-fuel ratio sensor 152 is normal but the detected air-fuel ratio AFu from the upstream air-fuel ratio sensor 152 is not input to the engine ECU 24 due to an abnormality in the communication line, etc.

[0031] When the post-start feedback control is executable in step S100, the post-start feedforward control described later is not executed, but the above-mentioned post-start feedback control is executed (step S110), and this routine ends. By such control, the catalyst atmosphere of the purification catalysts 136a, 138a that became lean due to the intermittent stop of the engine 22 is enriched, and the oxygen storage amount of the purification catalysts 136a, 138a is reduced, so that the deterioration of purification performance can be suppressed. In addition, since the fuel is injected at the target injection amount Qf* set using the detected air-fuel ratio AFu from the upstream air-fuel ratio sensor 152, the excessive amount of fuel injection is suppressed. This makes it possible to suppress the deterioration of emissions.

[0032] After the post-start feedback control is thus executed to enrich the catalyst atmosphere of the purification catalysts 136a, 138a, the target air-fuel ratio AF* is set to the stoichiometric air-fuel ratio, and the engine 22 is feedback controlled so that the difference between the target air-fuel ratio AF* and the detected air-fuel ratio AFu (rich side air-fuel ratio AFr) becomes small.

[0033] When the post-start feedback control is not executable in step S100, the post-start feedforward control is executed (step S110) without executing the post-start feedback control, and this routine is terminated. The post-start feedforward control sets the target intake air amount Ga* based on the target torque Te* from the HVECU 70, sets the base injection amount Qb so that the air-fuel ratio upstream of the purification catalyst 136a becomes the target air-fuel ratio AF* (theoretical air-fuel ratio) based on the target intake air amount Ga*, sets the target injection amount Qf* to a value (=Qb+Qad) obtained by adding a predetermined increase correction Qad to the base injection amount Qb, and controls the fuel injection valve 126 so that the fuel injection valve 126 injects fuel of the target injection amount Qf*. That is, in the feedforward control, the fuel injection valve 126 is feedforward controlled so that the fuel injection valve 126 injects fuel of the target injection amount Qf* (=Qb+Qad). The increase correction Qad is an injection amount determined in advance through experiments, analysis, etc., as an injection amount that can enrich the catalytic atmosphere of the purification catalysts 136a, 138a that have become lean due to the intermittent stop of the engine 22 while suppressing the deterioration of the emissions, thereby reducing the oxygen storage amount of the purification catalysts 136a, 138a and suppressing the deterioration of the purification performance. By such control, even when feedback control after starting cannot be executed, it is possible to enrich the catalytic atmosphere of the purification catalysts 136a, 138a that have become lean due to the intermittent stop of the engine 22. Therefore, it is possible to reduce the oxygen storage amount of the purification catalysts 136a, 138a and suppress the deterioration of the purification performance of the purification catalysts 136a, 138a. This makes it possible to suppress the deterioration of the emissions.

[0034] After the post-start feedforward control is thus executed to enrich the catalyst atmosphere of the purification catalysts 136a, 138a, the base injection amount Qb is set to the target injection amount Qf*, and the fuel injection valve 126 is feedforward controlled so that fuel is injected at the target injection amount Qf* (=Qb).

[0035] According to the hybrid vehicle 20 equipped with the internal combustion engine control device of the embodiment described above, it is possible to execute post-start feedback control that feedback controls the engine 22 so that the detected air-fuel ratio AFu detected by the upstream air-fuel ratio sensor 152 becomes the rich side air-fuel ratio AFr, or post-start feedforward control that feedforward controls the engine 22 so that the fuel injection amount is increased by the increase correction Qad from the base injection amount Qb corresponding to the stoichiometric air-fuel ratio. After the start of the engine 22 that is intermittently stopped, when post-start feedback control is executable, the post-start feedback control is executed without executing the post-start feedforward control, and when post-start feedback control is not executable, the post-start feedforward control is executed without executing the post-start feedback control, thereby suppressing deterioration of emissions.

[0036] According to the hybrid vehicle 20 equipped with the internal combustion engine control device of the embodiment, in the determination of step S100 of the post-start control routine in Fig. 3, the post-start feedback control can be executed when the upstream air-fuel ratio sensor 152 is normal and the detected air-fuel ratio AFu from the upstream air-fuel ratio sensor 152 is input to the engine ECU 24 via a connection line (not shown). In addition, the post-start feedback control cannot be executed when, for example, an abnormality occurs in the upstream air-fuel ratio sensor 152, or even if the upstream air-fuel ratio sensor 152 is normal, the detected air-fuel ratio AFu from the upstream air-fuel ratio sensor 152 is not input to the engine ECU 24 due to an abnormality in the communication line or the like.

[0037] However, the time when the feedback control after starting can be executed may be when the air flow meter 148 is normal, and the time when the feedback control after starting cannot be executed may be when an abnormality occurs in the air flow meter 148. In addition, the time when the feedback control after starting can be executed may be when air-fuel ratio learning, which is learning of the fuel injection amount for bringing the air-fuel ratio closer to the stoichiometric air-fuel ratio, has been completed, and the time when the feedback control after starting cannot be executed may be when air-fuel ratio learning has not been completed. In the case where such air-fuel ratio learning is executed using the detected air-fuel ratio AFd from the downstream air-fuel ratio sensor 154, the time when the feedback control after starting can be executed may be when the downstream air-fuel ratio sensor 154 is activated, and the time when the feedback control after starting cannot be executed may be when the downstream air-fuel ratio sensor 154 is not activated. Furthermore, in the case where the engine 22 has a canister that adsorbs evaporated fuel generated in the fuel tank, and a purge valve attached to a supply pipe for performing a purge that supplies evaporated gas containing the evaporated fuel adsorbed in the canister to the intake port of the internal combustion engine, a time when the post-start feedback control can be performed may be a time when learning regarding the purge concentration, which is the concentration of evaporated gas relative to the amount of gas supplied to the intake pipe, has been completed, and a time when the post-start feedback control cannot be performed may be a time when learning regarding the purge concentration has not been completed.

[0038] In the embodiment, the control device is in the form of a control device that controls the engine 22 of an engine device 21 mounted on a hybrid automobile 20 having an engine 22, a planetary gear 30, and motors MG1 and MG2. However, the control device may be in the form of a control device that controls the engine 22 of an engine device mounted on a so-called one-motor hybrid automobile having an engine and one motor. The control device may also be in the form of a control device that controls the engine of an engine device mounted on an automobile that runs using only the power from the engine. Furthermore, the control device may be in the form of a control device that controls the engine 22 of an engine device mounted on a stationary facility such as a construction facility.

[0039] The correspondence between the main elements of the embodiment and the main elements of the invention described in the section on Means for Solving the Problems will be described below. In the embodiment, the engine 22 corresponds to the "internal combustion engine", the purification catalyst 136a corresponds to the "purification catalyst", the upstream air-fuel ratio sensor 152 corresponds to the "air-fuel ratio sensor", and the engine ECU 24 corresponds to the "control device".

[0040] The correspondence between the main elements of the Examples and the main elements of the invention described in the Summary of the Problem column does not limit the elements of the invention described in the Summary of the Problem column, since the Examples are examples for specifically explaining the mode for implementing the invention described in the Summary of the Problem column. In other words, the interpretation of the invention described in the Summary of the Problem column should be based on the description in that column, and the Examples are merely a specific example of the invention described in the Summary of the Problem column.

[0041] Although the form for carrying out the present invention has been described above using examples, the present invention is not limited to these examples in any way, and it goes without saying that the present invention can be carried out in various forms without departing from the scope of the gist of the present invention. [Industrial Applicability]

[0042] The present invention can be used in the manufacturing industry of control devices for internal combustion engines. [Explanation of symbols]

[0043] 20 Hybrid vehicle, 22 Engine, 24 Engine ECU, 26 Crankshaft, 28 Damper, 30 Planetary gear, 36 Drive shaft, 38 Differential gear, 39a, 39b Drive wheel, 40 Motor ECU, 41, 42 Inverter, 43, 44 Rotational position sensor, 50 Battery, 51a Voltage sensor, 51b Current sensor, 51c Temperature sensor, 52 Battery ECU, 54 Power line, 70 HVECU, 80 Ignition switch, 81 Shift lever, 82 Shift position sensor, 83 Accelerator pedal, 84 Accelerator pedal position sensor, 85 Brake pedal, 86 Brake pedal position sensor, 88 Vehicle speed sensor, 89 Outside air temperature sensor, 122 Air cleaner, 123 Intake pipe, 124 Throttle valve, 124a Throttle valve position sensor, 124b throttle motor, 125 surge tank, 126 fuel injector, 128 intake valve, 129 combustion chamber, 130 spark plug, 132 piston, 133 exhaust valve, 134 exhaust pipe, 136, 138 purification device, 136a, 138a purification catalyst, 140 crank position sensor, 142 water temperature sensor, 144 cam position sensor, 148 air flow meter, 149 temperature sensor, 150 pressure sensor, 152 upstream air-fuel ratio sensor, 154 downstream air-fuel ratio sensor, MG1, MG2 motors.

Claims

[Claim 1] an internal combustion engine device including an internal combustion engine, a purification catalyst attached to an exhaust system of the internal combustion engine for purifying exhaust gas from the internal combustion engine, and an air-fuel ratio sensor for detecting an air-fuel ratio upstream of the purification catalyst in the exhaust system; A first motor; a planetary gear having a sun gear connected to a rotor of the first motor, a ring gear connected to a drive shaft coupled to a drive wheel, and a carrier connected to a crankshaft of the internal combustion engine; a second motor having a rotor connected to the drive shaft; A control device mounted on a hybrid vehicle and controlling the internal combustion engine of the internal combustion engine device, a feedback control for feedback controlling the internal combustion engine so that the detected air-fuel ratio detected by the air-fuel ratio sensor becomes a predetermined air-fuel ratio for making the upstream air-fuel ratio richer than the stoichiometric air-fuel ratio, or a feedforward control for feedforward controlling the internal combustion engine so that the fuel injection amount is increased by a predetermined amount from the injection amount corresponding to the stoichiometric air-fuel ratio, After starting the internal combustion engine that has been intermittently stopped by transitioning from a hybrid travel mode in which the vehicle travels with the internal combustion engine in operation to an electric travel mode in which the vehicle travels without the internal combustion engine in operation, when the feedback control is executable, the feedback control is executed without executing the feedforward control, and when the feedback control is not executable, the feedforward control is executed without executing the feedback control. A control device for an internal combustion engine.

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