JP7283199B2 - Control device for internal combustion engine - Google Patents

Description

The present invention relates to a control device for an internal combustion engine.

Patent Literature 1 discloses a control device that adjusts the fuel injection amount and the like so that the engine rotation speed at the time of initial explosion exceeds the resonance speed region when the engine is started.

JP 2009-228538 A

When starting the engine, the timing suitable for starting combustion control such as fuel injection and ignition differs depending on various conditions. Therefore, it is desirable to start combustion control according to these various conditions.

A control apparatus for an internal combustion engine for solving the above problems is applied to an internal combustion engine that is motored by an electric motor when there is a request to start. This control device is capable of controlling a state in which the amount of fuel leaked from a fuel injection valve of the internal combustion engine exceeds an allowable amount, and a state in which there is a possibility that the amount of fuel leaked from the fuel injection valve exceeds an allowable amount. is determined to be oiltightness leakage, an oiltightness determination process for determining the presence or absence of the oiltightness leakage is performed, and when it is determined that there is no oiltightness leakage, the motoring is executed in accordance with the start request. After the engine speed of the internal combustion engine, which rises due to the above, exceeds the resonance speed region of the internal combustion engine, the opening of the throttle valve so that the inside of the intake pipe downstream of the throttle valve of the internal combustion engine is in a specified negative pressure state. is executed, and after the inside of the intake pipe becomes the negative pressure state due to the execution of the negative pressure securing process, the combustion control of the internal combustion engine is started, and the oil leak occurs. is determined, after the engine rotation speed of the internal combustion engine, which increases due to the execution of the motoring in accordance with the start request, exceeds the resonance speed region, the negative pressure ensuring process is not executed, and the engine speed of the internal combustion engine increases. Start-up control is executed to start combustion control.

According to this configuration, after the engine speed exceeds the resonance speed region due to the execution of motoring, combustion control is started and the first explosion occurs. Here, when there is no oil leak in the fuel injection valve, after the engine rotation speed exceeds the resonance speed region, the intake air amount of the internal combustion engine decreases due to the negative pressure in the intake pipe. Combustion control is started after the state is reached. When combustion control is started after the amount of intake air has decreased in this manner, the initial explosion occurs more quickly than when combustion control is started immediately after the engine speed exceeds the resonance speed region. Since the engine output torque becomes smaller at that time, it is possible to suppress the starting shock that tends to occur at the time of the first explosion.

Here, if the negative pressure securing process is executed when there is an oil leak in the fuel injection valve, fuel may leak from the fuel injection valve due to the secured negative pressure. If fuel leaks from the valve, the leaked fuel may be discharged into the exhaust passage without burning. Therefore, in the same configuration, when there is an oil leak in the fuel injection valve, after the engine speed exceeds the resonance speed region, the combustion control is started without executing the negative pressure securing process. . Therefore, it is possible to prevent unburned fuel from being discharged into the exhaust passage when the engine is started.

In this way, according to the same configuration, when there is no oil leak in the fuel injection valve, after the engine speed exceeds the resonance speed region, the negative pressure is ensured and then the combustion control is started. Combustion control can be started at a time suitable for suppressing start-up shock. In addition, if there is an oil leak in the fuel injection valve, combustion control is started immediately after the engine speed exceeds the resonance speed region, thereby suppressing the discharge of unburned fuel into the exhaust passage. Combustion control can be started at a suitable time.

The negative pressure specified above is the negative pressure when the amount of intake air is reduced to the extent that the starting shock that may occur due to the initial explosion generated by the start of combustion control can be kept within the allowable range. For example, negative pressure obtained during idling is preferred.

In the above control device, the starting control includes a condition that the temperature of the internal combustion engine is equal to or lower than a specified temperature, a condition that the temperature of the battery that drives the electric motor is equal to or lower than a specified temperature, and charging of the battery. before the engine rotation speed of the internal combustion engine, which increases due to the execution of the motoring in accordance with the start request, reaches the resonance speed region when at least one of the conditions that the charging rate is equal to or less than a specified charging rate is established. A process of starting combustion control of the internal combustion engine may be executed.

When the temperature of the internal combustion engine is below a specified temperature and the friction of the internal combustion engine is large, or when the temperature of the battery that drives the electric motor is below a specified temperature and the output torque of the electric motor is low, or the charging rate of the battery is less than the specified charging rate and the drivable time of the electric motor is short, the amount of charge in the battery runs short before the engine rotation speed, which increases due to motoring, reaches the resonance speed region, and the engine rotation speed resonates. Exceeding the speed range can be difficult. Then, when the engine speed cannot actually exceed the resonance speed range, the combustion control is not started, so the internal combustion engine cannot be started. In this regard, according to the same configuration, if there is a possibility that the battery charge may run short before the engine speed reaches the resonance speed region, combustion control is performed before the engine speed reaches the resonance speed region. be started. Therefore, when combustion control starts, initial explosion occurs, and then when the engine speed increases and passes through the resonance speed range, engine vibration increases, but at least the internal combustion engine can be started.

In the above-described control device, when the engine is started and the required value of the output torque of the internal combustion engine is equal to or greater than a specified value, the torque is increased by executing the motoring according to the engine start request. After the engine speed of the internal combustion engine exceeds the resonance speed range, a process for starting combustion control of the internal combustion engine may be executed without executing the negative pressure ensuring process.

According to this configuration, when the required value of the output torque of the internal combustion engine when starting the internal combustion engine is greater than a specified value, that is, when it is desired to quickly increase the engine output when starting the engine, the engine rotation speed is increased. After exceeding the resonance speed range, combustion control is started without executing the negative pressure securing process. Therefore, after the engine rotation speed exceeds the resonance speed region, compared to the case where the negative pressure securing process is executed to secure the negative pressure and then the combustion control is started, the engine is started earlier. Engine output can be increased.

In the above control device, the internal combustion engine is provided with a sensor for detecting fuel pressure in the fuel injection valve, and the oil tightness determination process detects the amount of fuel pressure decrease due to the stoppage of the internal combustion engine. may be calculated from the detected value, and the process of determining that there is an oil leak may be executed when the calculated amount of decrease is equal to or greater than a specified determination value.

If there is an oiltightness leak in the fuel injection valve, the fuel pressure in the fuel injection valve decreases while the internal combustion engine is stopped. It is possible to determine the presence or absence of Therefore, in the same configuration, the amount of decrease in fuel pressure is calculated from the detected value of the sensor, and when the calculated amount of decrease is equal to or greater than a specified determination value, a process for determining that there is an oil leak is executed. Therefore, according to this configuration, it is possible to appropriately determine whether or not there is an oil leak.

In the control device described above, the oil tightness determination process may include determining that there is an oil tightness leak when the operation stop time of the internal combustion engine before starting is equal to or longer than a specified determination value.

When the fuel injection valve has an oil leak, fuel gradually leaks from the fuel injection valve while the operation of the internal combustion engine is stopped. If motoring is performed with a large amount of leakage in this manner, unburned fuel may be discharged into the exhaust passage before combustion is started. Therefore, when the amount of leaked fuel is large, the combustion control is started as early as possible to burn the leaked fuel as early as possible, so that the amount of unburned fuel discharged into the exhaust passage can be suppressed. Therefore, in the same configuration, when the operation stop time of the internal combustion engine before starting is longer than or equal to a specified determination value, the process of determining that there is an oil leak is executed. Therefore, when the operation stop time is longer than the prescribed judgment value and there is a possibility that the amount of fuel leaking from the fuel injection valve is large, it is judged that there is an oil leak. , the combustion control is promptly started without executing the negative pressure securing process. Therefore, even if there is an oil leak in the fuel injection valve, the amount of unburned fuel discharged into the exhaust passage can be suppressed.

In the control device, when the negative pressure securing process is executed, the ignition timing of the internal combustion engine when the combustion control is started is set to the ignition timing at which the engine output is the lowest within the range in which the mixture can be combusted. may be executed to set the output suppressing ignition timing.

According to this configuration, the ignition timing at which the combustion control is started is set to the output suppressing ignition timing, so that the engine output at the time of the initial explosion is suppressed. Therefore, when the negative pressure securing process is executed to suppress the starting shock, the starting shock can be further suppressed.

In the above control device, when the electric motor is the first electric motor and the electric motor for transmitting power to the drive shaft connected to the driving wheels of the vehicle is the second electric motor, the output shaft of the internal combustion engine is the output of the internal combustion engine. to the output shaft of the first electric motor and the drive shaft, and the required value of the output torque of the second electric motor when the combustion control is started is lower than "0 Nm" torque, and when the required ignition timing after the occurrence of the initial explosion is on the advanced side of the output suppression ignition timing, until the required value of the output torque of the second electric motor exceeds "0 Nm", A process of suspending the change of the ignition timing from the output suppression ignition timing to the required ignition timing may be executed.

When an internal combustion engine mounted on a vehicle having the planetary gear mechanism is motored by the first electric motor and started, the required value of the output torque of the second electric motor ranges from a torque lower than 0 Nm to 0 Nm. When the required value of the output torque of the second electric motor straddles "0 Nm" in this way, the gears of the planetary gear mechanism generate rattling noise. There is Here, if the output torque of the internal combustion engine sharply increases when the required value of the output torque of the second electric motor crosses over "0 Nm", there is a possibility that such rattling noise will increase.

In this respect, according to the same configuration, when the required ignition timing after the occurrence of the initial explosion is on the advanced side of the output suppression ignition timing and the engine output increases, the output torque of the second electric motor is requested. The change of the ignition timing from the output suppressing ignition timing to the required ignition timing is suspended until the value exceeds "0 Nm". Therefore, the rapid increase in the output torque of the internal combustion engine when the required value of the output torque of the second electric motor crosses over "0 Nm" can be suppressed, thereby suppressing the rattling noise generated from the planetary gear mechanism.

In the above control device, when the electric motor is the first electric motor and the electric motor for transmitting power to the drive shaft connected to the driving wheels of the vehicle is the second electric motor, the output shaft of the internal combustion engine is the output of the internal combustion engine. to the output shaft of the first electric motor and the drive shaft, and the required value of the output torque of the second electric motor when the combustion control is started is lower than "0 Nm" torque, and when the required ignition timing after the occurrence of the initial explosion is on the advanced side of the output suppressing ignition timing, the ignition timing is changed from the output suppressing ignition timing to the required ignition timing. The rate of change of the ignition timing in the process until the requested value of the output torque of the second electric motor exceeds "0 Nm" is defined as the rate of change until the requested value of the output torque of the second electric motor exceeds "0 Nm" You may perform the process which makes it smaller than a later change rate.

As described above, when starting an internal combustion engine mounted on a vehicle equipped with the planetary gear mechanism by motoring with the first electric motor, the required value of the output torque of the second electric motor is higher than "0 Nm". There are cases where the torque changes from a low torque to a torque exceeding "0 Nm". Sound may occur. Here, if the output torque of the internal combustion engine sharply increases when the required value of the output torque of the second electric motor crosses over "0 Nm", there is a possibility that such rattling noise will increase.

In this respect, according to the same configuration, when the required ignition timing after the occurrence of the initial explosion is on the advanced side of the output suppression ignition timing and the engine output increases, the output torque of the second electric motor is requested. Until the value exceeds "0 Nm", the rate of change of the ignition timing in the process of changing the ignition timing from the output suppression ignition timing to the required ignition timing is reduced, so that the increase in the output torque of the internal combustion engine is moderated. . Therefore, the rapid increase in the output torque of the internal combustion engine when the required value of the output torque of the second electric motor crosses over "0 Nm" can be suppressed, thereby suppressing the rattling noise generated from the planetary gear mechanism.

In the above control device, the internal combustion engine includes a variable valve mechanism that changes the valve timing of an intake valve, and when the negative pressure ensuring process is executed, the valve timing when the combustion control is started is changed. may be set to the output suppression valve timing, which is the valve timing at which the engine output is the lowest within the range in which the air-fuel mixture can be combusted.

According to this configuration, the valve timing at which the combustion control is started is set to the output suppression valve timing, so that the engine output at the time of the initial explosion is suppressed. Therefore, when the negative pressure securing process is executed to suppress the starting shock, the starting shock can be further suppressed.

In the above control device, when the electric motor is the first electric motor and the electric motor for transmitting power to the drive shaft connected to the driving wheels of the vehicle is the second electric motor, the output shaft of the internal combustion engine is the output of the internal combustion engine. to the output shaft of the first electric motor and the drive shaft, and the required value of the output torque of the second electric motor when the combustion control is started is lower than "0 Nm" torque, and when the required valve timing after the occurrence of the initial explosion is on the advance side of the output suppression valve timing, until the required value of the output torque of the second electric motor exceeds "0 Nm", A process of suspending the change of the valve timing from the output suppression valve timing to the required valve timing may be executed.

As described above, when starting an internal combustion engine mounted on a vehicle equipped with the planetary gear mechanism by motoring with the first electric motor, the required value of the output torque of the second electric motor is higher than "0 Nm". There are cases where the torque changes from a low torque to a torque exceeding "0 Nm". Sound may occur. Here, if the output torque of the internal combustion engine sharply increases when the required value of the output torque of the second electric motor crosses over "0 Nm", there is a possibility that such rattling noise will increase.

In this regard, according to the same configuration, when the required valve timing after the occurrence of the initial explosion is on the advanced side of the output suppression valve timing and the engine output increases, the output torque of the second electric motor is requested. The change of the valve timing from the output suppression valve timing to the required valve timing is suspended until the value exceeds "0 Nm". Therefore, the rapid increase in the output torque of the internal combustion engine when the required value of the output torque of the second electric motor crosses over "0 Nm" can be suppressed, thereby suppressing the rattling noise generated from the planetary gear mechanism.

In the above control device, when the electric motor is the first electric motor and the electric motor for transmitting power to the drive shaft connected to the driving wheels of the vehicle is the second electric motor, the output shaft of the internal combustion engine is the output of the internal combustion engine. to the output shaft of the first electric motor and the drive shaft, and the required value of the output torque of the second electric motor when the combustion control is started is lower than "0 Nm" torque, and when the required valve timing after the occurrence of the initial explosion is on the advance side of the output suppressing valve timing, the valve timing is changed from the output suppressing valve timing to the required valve timing. The rate of change of the valve timing in the process until the requested value of the output torque of the second electric motor exceeds "0 Nm" is calculated as follows: You may perform the process which makes it smaller than a later change rate.

As described above, when starting an internal combustion engine mounted on a vehicle equipped with the planetary gear mechanism by motoring with the first electric motor, the required value of the output torque of the second electric motor is higher than "0 Nm". There are cases where the torque changes from a low torque to a torque exceeding "0 Nm". Sound may occur. Here, if the output torque of the internal combustion engine sharply increases when the required value of the output torque of the second electric motor crosses over "0 Nm", there is a possibility that such rattling noise will increase.

In this regard, according to the same configuration, when the required valve timing after the occurrence of the initial explosion is on the advanced side of the output suppression valve timing and the engine output increases, the output torque of the second electric motor is requested. Until the value exceeds "0 Nm", the change rate of the valve timing in the process of changing the valve timing from the output suppression valve timing to the required valve timing is reduced, so the increase in the output torque of the internal combustion engine is moderated. . Therefore, the rapid increase in the output torque of the internal combustion engine when the required value of the output torque of the second electric motor crosses over "0 Nm" can be suppressed, thereby suppressing the rattling noise generated from the planetary gear mechanism.

1 is a schematic diagram showing the configuration of a hybrid vehicle provided with a control device for an internal combustion engine according to a first embodiment; FIG. The schematic diagram which shows the structure of the internal combustion engine of the same embodiment. 4 is a flow chart showing a procedure of start-up control executed by the control device of the same embodiment; 6 is a flowchart showing the procedure of processing executed by the control device of the second embodiment; 4 is a flowchart showing the procedure of processing executed by the control device of the embodiment; 10 is a flowchart showing the procedure of processing executed by the control device of the third embodiment; 4 is a flowchart showing the procedure of processing executed by the control device of the embodiment; FIG. 5 is a flow chart showing a part of the procedure of start-up control in a modified example of the first embodiment; FIG.

(First embodiment)
A first embodiment embodying a control device for an internal combustion engine will be described below with reference to FIGS. 1 to 3. FIG.

As shown in FIG. 1, a vehicle 500 is a hybrid vehicle that includes an internal combustion engine 10 and an electric motor as prime movers. and a second motor generator (hereinafter referred to as a second MG) 72 that is a second electric motor.

Vehicle 500 includes a planetary gear mechanism 40 . The planetary gear mechanism 40 is a mechanism for distributing the output of the internal combustion engine 10 to the rotor, which is the output shaft of the first MG 71, and the drive shaft 60 connected to the drive wheels 62. It has a ring gear 42 that is connected to it. A plurality of pinion gears meshing with both the sun gear 41 and the ring gear 42 are arranged between the sun gear 41 and the ring gear 42 , and each pinion gear is supported by a carrier 44 .

A crankshaft 34 of the internal combustion engine 10 is connected to the carrier 44 , and a rotor of the first MG 71 is connected to the sun gear 41 . A drive shaft 60 is connected to the ring gear 42 , and the drive shaft 60 is connected to drive wheels 62 via a differential gear 61 . The first MG 71 functions as a generator that generates power using the engine output, and also functions as a starting starter (electric motor) when the internal combustion engine 10 is started.

A rotor of the second MG 72 is connected to a drive shaft 60 via a speed reduction mechanism 50 . The second MG 72 functions as an electric motor that generates driving force for the drive wheels 62 and also functions as a generator that generates power by regenerative braking when the vehicle 500 is decelerating.

The first MG 71 and the second MG 72 exchange electric power with a battery 78 via a PCU (Power Control Unit) 200 . PCU 200 includes a boost converter that boosts and outputs a DC voltage input from battery 78, an inverter that converts the DC voltage boosted by the boost converter into AC voltage and outputs the AC voltage to MGs 71 and 72, and the like.

As shown in FIG. 2, in the internal combustion engine 10, air is drawn into a combustion chamber 30 through an intake passage 11 having a surge tank 13 and an intake port 12, and is injected into the intake port 12 from a fuel injection valve 31. Fuel is supplied to the combustion chamber 30 . When the mixture composed of air and fuel supplied to the combustion chamber 30 is ignited by the spark plug 32, the mixture burns and the piston 33 reciprocates to move the output shaft of the internal combustion engine 10. , the crankshaft 34 rotates. The air-fuel mixture after combustion is discharged as exhaust from the combustion chamber 30 to the exhaust passage 21 through the exhaust port 22 .

An intake passage 11 of the internal combustion engine 10 is provided with a throttle valve 14 for adjusting the amount of intake air. The opening of this throttle valve 14 is adjusted by an electric motor.
The intake port 12 is provided with an intake valve 15 , and the exhaust port 22 is provided with an exhaust valve 25 . These intake valves 15 and exhaust valves 25 open and close with the rotation of the intake camshaft 16 and the exhaust camshaft 26 to which the rotation of the crankshaft 34 is transmitted, respectively.

The intake camshaft 16 is provided with a variable valve mechanism 17 that changes the valve timing of the intake valves 15 by adjusting the relative phase of the intake camshaft 16 with respect to the crankshaft 34 .

As shown in FIG. 1 , control of the internal combustion engine 10 and control of the first MG 71 and the second MG 72 via the PCU 200 are performed by a control device 100 mounted on the vehicle 500 .

The control device 100 includes a central processing unit (hereinafter referred to as CPU) 110 and a memory 120 in which control programs and data are stored. Various controls are executed by the CPU 110 executing programs stored in the memory 120 . Although not shown, the control device 100 is composed of a plurality of control units such as a control unit for the internal combustion engine 10 and a control unit for the PCU 200 .

The control device 100 includes a crank angle sensor 80 that detects the rotation angle of the crankshaft 34, a cam angle sensor 81 that detects the phase of the intake camshaft 16, an air flow meter 82 that detects the intake air amount GA of the internal combustion engine 10, an internal combustion A water temperature sensor 83 is connected to detect a cooling water temperature THW, which is the temperature of the cooling water of the engine 10 . The control device 100 also includes a fuel pressure sensor 84 that detects the fuel pressure FP that is the pressure of the fuel in the fuel injection valve 31, a vehicle speed sensor 85 that detects the vehicle speed SP of the vehicle 500, and an accelerator operation amount that is the operation amount of the accelerator pedal. An accelerator position sensor 86 for detecting ACCP and a temperature sensor 88 for detecting battery temperature THB, which is the temperature of the battery 78, are also connected. Output signals from these various sensors are input to the control device 100 . The control device 100 calculates the engine rotation speed NE based on the output signal Scr of the crank angle sensor 80, and calculates the intake valve 15 speed based on the output signal Scr of the crank angle sensor 80 and the output signal Sca of the cam angle sensor 81. Calculate the actual valve timing, which is the actual valve timing of Control device 100 also calculates the charging rate (hereinafter referred to as SOC) of battery 78 .

Then, the control device 100 grasps the engine operating state based on the detection signals of the various sensors, and according to the grasped engine operating state, controls the fuel injection of the fuel injection valve 31, controls the ignition timing of the spark plug 32, and controls the intake air. Various engine controls such as valve timing control of the valve 15 and opening degree control of the throttle valve 14 are performed.

As the valve timing control, the control device 100 calculates a required valve timing, which is a control target value of the valve timing of the intake valve 15, based on the engine speed NE, the engine load factor KL, and the like. Then, the valve timing control of the intake valve 15 is performed by controlling the drive of the variable valve mechanism 17 so that the actual valve timing becomes the required valve timing. In the present embodiment, the timing when the valve timing of the intake valve 15 is the most retarded timing is set as the reference timing, and the valve timing of the intake valve 15 is expressed using the advance amount from this reference timing. there is

Further, as the ignition timing control, the control device 100 calculates the required ignition timing, which is the control target value of the ignition timing, based on the engine speed NE, the engine load factor KL, and the like. Then, when the rotational position of the crankshaft 34 reaches a position corresponding to the required ignition timing, the spark plug 32 discharges sparks to ignite the air-fuel mixture. In the present embodiment, the ignition timing is expressed using the advance angle amount from this reference position with compression top dead center as a reference.

Then, control device 100 calculates a required vehicle output, which is a required value of driving force of vehicle 500, based on accelerator operation amount ACCP, vehicle speed SP, and the like. Further, the control device 100 controls the engine required torque TE, which is the required value of the output torque of the internal combustion engine 10, and the first MG required torque, which is the required value of the power running torque or regenerative torque of the first MG 71, based on the vehicle required output, SOC, and the like. TM1 and a second MG request torque TM2, which is a request value of power running torque or regenerative torque of the second MG 72, are calculated respectively. Then, the control device 100 performs output control of the internal combustion engine 10 according to the engine required torque TE, and performs torque control of the first MG 71 and the second MG 72 according to the first MG required torque TM1 and the second MG required torque TM2. Thus, torque control necessary for running the vehicle 500 is performed.

Further, the control device 100 stops the operation of the internal combustion engine 10 when the required engine torque TE is "0" and the operation of the internal combustion engine 10 can be stopped. Then, when the engine required torque TE exceeds "0", the control device 100 starts to start the internal combustion engine 10 which has been stopped.

Next, a description will be given of the starting control that is performed when starting the internal combustion engine 10 that has been stopped.
FIG. 3 shows a processing procedure of start-up control performed by the control device 100. As shown in FIG. The series of processes shown in FIG. 3 is started when a start request is issued to the internal combustion engine 10 whose operation is stopped. It is realized by In the following description, step numbers are represented by numerals prefixed with "S".

When starting this control, the control device 100 starts motoring (S100). This motoring is control to rotate the crankshaft 34 of the internal combustion engine 10 in a state where combustion is stopped by the power of the first MG 71. When the motoring is started and the crankshaft 34 rotates, each cylinder of the internal combustion engine 10 Air is sucked in and out.

Next, the control device 100 determines whether or not at least one of the following conditions (A) to (C) is satisfied (S110).
Condition (A): current cooling water temperature THW≦threshold THWref.

Condition (B): current battery temperature THB≦threshold THBref.
Condition (C): current SOC≦threshold SOCref.
The following values are set in advance for the threshold THWref, the threshold THBref, and the threshold SOCref.

First, in this embodiment, basically, combustion control such as fuel injection and ignition is started after the engine speed, which is increased by motoring, exceeds the resonance speed region of the internal combustion engine 10 .

Here, when the temperature of the internal combustion engine 10 is low and the friction of the internal combustion engine 10 is large, or the temperature of the battery 78 that drives the first MG 71 is below the predetermined temperature and the When the output torque of the 1MG 71 is low, or when the SOC is equal to or less than the specified SOC and the drivable time of the 1MG 71 is short, the amount of electricity stored in the battery 78 is discharged before the engine speed, which increases due to motoring, reaches the resonance speed region. There is a possibility that it will be difficult for the engine speed to exceed the resonance speed range. Therefore, the threshold THWref, the threshold THBref, and the threshold SOCref are set to determine whether or not there is a possibility that the engine rotation speed will be difficult to exceed the resonance speed region due to the shortage of the charge amount of the battery 78 described above. are set to values that can be appropriately determined.

When it is determined that at least one of the conditions (A), (B), and (C) is established (S110: YES), the control device 100 determines that the current engine speed NE is equal to or greater than the first threshold value NErefa. (S120). The first threshold value NErefa is an engine rotation speed lower than the lowest rotation speed within the range of the resonance speed range of the internal combustion engine 10, and the engine rotation speed at which the combustion operation of the air-fuel mixture can be started by starting the combustion control. A lower limit value for speed is set in advance.

The control device 100 repeatedly executes the process of S120 until the engine speed NE reaches or exceeds the first threshold value NErefa. When the control device 100 determines that the engine rotation speed NE is equal to or greater than the first threshold value NErefa (S120: YES), the control device 100 starts fuel injection with a fuel injection amount suitable for starting the engine, and starts the ignition suitable for starting the engine. Combustion control is started by starting ignition at the timing (S190). Then, this control ends.

On the other hand, when it is determined in S110 that all of the conditions (A), (B), and (C) are not satisfied (S110: NO), the control device 100 sets the current engine speed NE to the resonance speed It is determined whether or not the threshold is exceeded (S130). In this S130, when the current engine speed NE is equal to or higher than a predetermined second threshold value, the control device 100 determines that the current engine speed NE has exceeded the resonance speed range. The second threshold value is set to an engine rotation speed that is higher than the maximum rotation speed within the resonance speed range of the internal combustion engine 10 .

Then, the control device 100 repeats the processing of S130 until the engine speed NE exceeds the resonance speed range, and when it determines that the engine speed NE has exceeded the resonance speed range (S130: YES), the current engine required torque It is determined whether or not TE is greater than or equal to a threshold TEref (S140). As this threshold TEref, based on the fact that the required engine torque TE is equal to or greater than the threshold TEref, it is appropriately determined that there is a request from the driver of the vehicle 500 to promptly increase the engine output at the time of starting the engine this time. The magnitude of the value is set in advance so that it can be used.

When it is determined that the engine required torque TE is equal to or greater than the threshold TEref (S140: YES), the control device 100 immediately starts fuel injection and ignition without executing the below-described negative pressure securing process, thereby causing combustion to occur. Control is started (S190), and this process is terminated.

On the other hand, when it is determined in S140 that the engine required torque TE is less than the threshold TEref (S140: NO), the control device 100 determines whether or not there is an oil leak in the fuel injection valve 31 (S150). . At S150, the control device 100 executes oil tightness determination processing for determining whether or not there is an oil tightness leak in the fuel injection valve 31. FIG. In this oil leak determination process, the value obtained by subtracting the fuel pressure FPs detected when the start request is generated from the fuel pressure FPe detected immediately after the operation of the internal combustion engine 10 is stopped, that is, the fuel pressure while the operation of the internal combustion engine 10 is stopped The amount of decrease in FP is calculated. If the calculated amount of decrease is equal to or greater than a preset threshold value ΔFpref, it is determined that there is oiltightness leakage, and if the calculated amount of decrease is less than the threshold value ΔFpref, it is determined that there is no oiltightness leakage. do. It should be noted that this oil tightness determination process may be executed at another timing, for example, when a request to start the internal combustion engine 10 is generated. get.

If it is determined that there is an oil leak (S150: YES), the control device 100 starts combustion control by immediately starting fuel injection and ignition without executing the below-described negative pressure securing process. (S190), this processing ends.

On the other hand, when it is determined in S150 that there is no oil leak (S150: NO), the control device 100 changes the throttle opening, which is the opening of the throttle valve 14, to the idle opening, which is the opening during idling. Set (S160). The process of S160 for setting the throttle opening to the idling opening when motoring is performed is performed when the inside of the intake pipe downstream of the throttle valve 14 of the internal combustion engine 10 (for example, the inside of the surge tank 13) is under a specified negative pressure. The negative pressure ensuring process is performed by adjusting the opening of the throttle valve 14 so as to achieve the above state.

When the negative pressure securing process is started in this way, the control device 100 sets the output suppressing ignition timing as the required ignition timing when starting combustion control, and sets the output suppressing valve timing as the required valve timing when starting combustion control. A timing is set (S170). The output suppressing ignition timing is a predetermined ignition timing at which the engine output is the lowest within a range in which the air-fuel mixture can be combusted. Further, the output suppression valve timing is a predetermined valve timing at which the engine output is the lowest within a range in which the air-fuel mixture can be combusted. For example, in the case of the present embodiment, the most retarded valve timing within the variable range of the valve timing of the intake valve 15 is set as the output suppression valve timing.

Next, the control device 100 determines whether or not the intake pipe pressure P, which is the current pressure in the surge tank 13, has become equal to or less than the threshold value Pref, that is, whether or not the specified negative pressure state has occurred (S180). . This threshold value Pref is set to the negative pressure when the intake air amount is reduced to the extent that the starting shock that may occur due to the initial explosion generated by the start of combustion control can be kept within the allowable range. For example, in this embodiment, the negative pressure obtained during idling is set. Further, when the number of revolutions of the crankshaft 34 after the throttle opening is set to the idle opening in S160 reaches a predetermined number or more, the control device 100 determines that the intake pipe pressure P has become equal to or less than the threshold value Pref. . In addition, the intake pipe pressure P is actually measured to determine whether or not the measured value is equal to or less than the threshold value Pref, or if the intake air amount GA is equal to or less than the intake air amount during idling, the intake pipe It may be determined that the pressure P has become equal to or less than the threshold value Pref.

Then, the control device 100 repeats the processing of S180 until it determines that the intake pipe pressure P has become equal to or less than the threshold value Pref, and when it determines that the intake pipe pressure P has become equal to or less than the threshold value Pref (S180: YES), the engine starts. Combustion control is started by starting fuel injection with a fuel injection amount suitable for , and starting ignition at the output suppressing ignition timing (S190). Then, the control device 100 ends this control.

Next, the operation and effects of this embodiment will be described.
(1) After the engine rotation speed NE exceeds the resonance speed region due to execution of motoring by the first MG 71, combustion control is started and initial explosion occurs. Here, when it is determined in the process of S130 shown in FIG. (S150: NO), the negative pressure securing process is executed in the process of S160. When it is determined that the amount of intake air in the internal combustion engine 10 has decreased due to the negative pressure in the surge tank 13 resulting from the execution of the negative pressure ensuring process (S180: YES), Combustion control is started in the process of S190. Since the combustion control is started after the intake air amount is reduced in this way, the initial explosion is faster than the case where the combustion control is started immediately after the engine speed NE exceeds the resonance speed region. Since the engine output torque at the time of occurrence is small, it is possible to suppress the starting shock that tends to occur at the time of initial explosion.

On the other hand, if the negative pressure securing process is executed when there is an oil leak in the fuel injection valve 31, fuel may leak from the fuel injection valve 31 due to the secured negative pressure. If fuel leaks from the injection valve 31, the leaked fuel may be discharged to the exhaust passage 21 without being burned. In this regard, in the present embodiment, after it is determined in the process of S130 shown in FIG. If so (S150: YES), the combustion control is started in the process of S190 without executing the negative pressure ensuring process. Therefore, it is possible to prevent unburned fuel from being discharged into the exhaust passage 21 when the engine is started.

In this manner, when there is no oil leak in the fuel injection valve 31, after the engine speed exceeds the resonance speed region, the negative pressure is secured and then the combustion control is started, thereby suppressing the starting shock. Combustion control can be started at a time suitable for Further, when there is an oil leak in the fuel injection valve 31, the discharge of unburned fuel to the exhaust passage 21 is prevented by immediately starting combustion control after the engine speed NE exceeds the resonance speed region. Combustion control can be started at a time suitable for suppression.

(2) When at least one of the above conditions (A) to (C) is satisfied, the amount of charge in the battery 78 runs short before the engine speed, which increases due to motoring, reaches the resonance speed region. As a result, it may become difficult for the engine speed to exceed the resonance speed range. Then, when the engine speed cannot actually exceed the resonance speed range, the combustion control is not started, so the internal combustion engine 10 cannot be started.

In this respect, in the present embodiment, when it is determined in the process of S110 shown in FIG. : YES), by executing the processes of S120 and S190, combustion control is started before the engine speed reaches the resonance speed region. Therefore, when the combustion control starts, the initial explosion occurs, and when the engine speed increases and passes through the resonance speed range, the engine vibration increases, but at least the internal combustion engine 10 can be started.

(3) After it is determined in the process of S130 shown in FIG. 3 that the engine speed has exceeded the resonance speed range, in the process of S140, the engine required torque TE when starting the internal combustion engine 10 is equal to or greater than the threshold TEref. is large (S140: YES), i.e., when there is a request to increase the engine output immediately upon starting the engine, the process of S190 is performed without executing the above-described negative pressure securing process. Control begins. Therefore, after the engine rotation speed exceeds the resonance speed region, compared to the case where the negative pressure securing process is executed to secure the negative pressure and then the combustion control is started, the engine is started earlier. Engine output can be increased.

(4) If there is an oil leak in the fuel injection valve 31, the fuel pressure FP in the fuel injection valve 31 decreases while the operation of the internal combustion engine 10 is stopped. It is possible to determine the presence or absence of oil tightness leakage based on the amount of decrease.

Therefore, in the present embodiment, in the oil-tightness determination process in S150 shown in FIG. Since it is determined that there is an oiltightness leak when , it is possible to appropriately determine whether or not there is an oiltightness leak.

(5) When the negative pressure ensuring process is executed in the process of S160 shown in FIG. Since the ignition timing for suppression is set, the engine output when the initial explosion occurs is suppressed. Therefore, when the negative pressure securing process is executed to suppress the starting shock, the starting shock can be further suppressed.

(6) When the negative pressure ensuring process is executed in the process of S160 shown in FIG. Since the valve timing for suppression is set, the engine output is suppressed when the first explosion occurs. Therefore, when the negative pressure securing process is executed to suppress the starting shock, the starting shock can be further suppressed.

(Second embodiment)
Next, a second embodiment of the internal combustion engine control device will be described with reference to FIGS. 4 and 5. FIG.

When the internal combustion engine 10 mounted on the vehicle 500 equipped with the planetary gear mechanism 40 is motored and started by the first MG 71, the second MG required torque TM2 is reduced from a torque lower than "0 Nm" to "0 Nm". It may change to excessive torque. When the second MG required torque TM2 straddles "0 Nm" in this manner, the gears of the planetary gear mechanism 40 are likely to generate tooth rattle noise due to backlash. Here, if the output torque of the internal combustion engine 10 sharply increases when the second MG required torque TM2 straddles "0 Nm", there is a possibility that such rattling noise will increase.

Therefore, in this embodiment, the control device 100 executes each process shown in FIGS. 4 and 5 in order to suppress the occurrence of such rattling noise.
The series of processes shown in FIGS. 4 and 5 are executed when combustion control is started with the process of S170 shown in FIG. be.

When the process shown in FIG. 4 is started, the control device 100 determines whether or not the current second MG required torque TM2 is lower than "0 Nm" (S300). When determining that the second MG request torque TM2 is not lower than "0 Nm" (S300: NO), the control device 100 terminates this process.

On the other hand, when determining that the second MG required torque TM2 is torque lower than "0 Nm" (S300: YES), the control device 100 determines whether or not the initial explosion has occurred (S310).

Then, the control device 100 repeatedly executes the processing of S310 until it is determined that the first explosion has occurred. It is determined whether or not the timing is on the advance side of the ignition timing (S320).

If it is determined that the required ignition timing after the occurrence of the initial explosion is not on the advanced side of the output suppression ignition timing (S320: NO), the control device 100 ends this process.
On the other hand, if it is determined that the required ignition timing after the occurrence of the initial explosion is on the advanced side of the output suppression ignition timing (S320: YES), the control device 100 sets the ignition timing of the internal combustion engine 10 to the output suppression ignition timing. The ignition timing is maintained (S330).

Next, the control device 100 determines whether or not the current second MG request torque TM2 is greater than "0 Nm", that is, whether or not the current second MG request torque TM2 exceeds "0 Nm" ( S340).

Then, the control device 100 repeatedly executes the process of S340 until it determines that the second MG required torque TM2 has exceeded "0 Nm".
Next, when the control device 100 determines that the second MG required torque TM2 has exceeded "0 Nm" (S340: YES), the ignition timing of the internal combustion engine 10 is advanced from the output suppression ignition timing. (S350), and the process ends.

Further, when the process shown in FIG. 5 is started, the control device 100 determines whether or not the current second MG required torque TM2 is lower than "0 Nm" (S300). When determining that the second MG request torque TM2 is not lower than "0 Nm" (S300: NO), the control device 100 terminates this process.

On the other hand, when determining that the second MG request torque TM2 is torque lower than "0 Nm" (S400: YES), the control device 100 determines whether or not the initial explosion has occurred (S410).

Then, the control device 100 repeatedly executes the processing of S410 until it is determined that the first explosion has occurred. It is determined whether or not the timing is on the advance side of the valve timing (S420).

If it is determined that the required valve timing after the occurrence of the first explosion is not on the advanced side of the output suppression valve timing (S420: NO), the control device 100 terminates this process.

On the other hand, if it is determined that the required valve timing after the occurrence of the first explosion is on the advanced side of the output suppression valve timing (S420: YES), the control device 100 sets the valve timing of the intake valve 15 to the output suppression valve timing. The valve timing is maintained (S430).

Next, the control device 100 determines whether or not the current second MG request torque TM2 is greater than "0 Nm", that is, whether or not the current second MG request torque TM2 exceeds "0 Nm" ( S440).

Then, the control device 100 repeatedly executes the process of S440 until it determines that the second MG required torque TM2 has exceeded "0 Nm".
Next, when the control device 100 determines that the second MG required torque TM2 has exceeded "0 Nm" (S440: YES), the valve timing of the intake valve 15 is advanced to the timing of the output suppression valve timing. The valve timing is changed to the required valve timing (S450), and the process ends.

Next, the operation and effects of this embodiment will be described.
(7) In the process of S320 shown in FIG. 4, when it is determined that the required ignition timing after the occurrence of the first explosion is on the advanced side of the output suppression ignition timing (S320: YES), the requested If setting the ignition timing increases the engine output, the processes of S330, S340 and S350 are executed. As a result, the change of the ignition timing from the output suppressing ignition timing to the required ignition timing is suspended until the second MG required torque TM2 exceeds "0 Nm". Therefore, the rapid increase in the output torque of the internal combustion engine 10 is suppressed when the second MG required torque TM2 straddles "0 Nm", thereby suppressing the rattling noise generated from the planetary gear mechanism 40.

(8) In the process of S420 shown in FIG. 5, when it is determined that the required valve timing after the occurrence of the initial explosion is on the advance side of the output suppression valve timing (S420: YES), the required If the engine output is increased by setting the valve timing, the processes of S430, S440 and S450 are executed. As a result, the change of the valve timing from the output suppression valve timing to the required valve timing is suspended until the second MG required torque TM2 exceeds "0 Nm". Therefore, the rapid increase in the output torque of the internal combustion engine 10 is suppressed when the second MG required torque TM2 crosses over "0 Nm", and this also suppresses the rattling noise generated from the planetary gear mechanism 40.

(Third embodiment)
Next, a third embodiment of the internal combustion engine control device will be described with reference to FIGS. 6 and 7. FIG.

In the second embodiment, in order to suppress gear rattling noise generated from the planetary gear mechanism 40 when the second MG required torque TM2 crosses "0 Nm", the output is suppressed until the second MG required torque TM2 exceeds "0 Nm". The change of the ignition timing from the normal ignition timing to the required ignition timing is suspended. Further, the change of the valve timing from the output suppression valve timing to the above-described required valve timing is suspended until the second MG required torque TM2 exceeds "0 Nm".

On the other hand, in the present embodiment, instead of the processes of S330 and S350 described with reference to FIG. 4, the processes of S500 and S510, which will be described later, are executed to suppress the occurrence of the rattling noise. Further, in the present embodiment, the generation of the rattling noise is suppressed by executing the processes of S600 and S610, which will be described later, in place of the processes of S430 and S450 described with reference to FIG.

The present embodiment will be described below, centering on the differences from the second embodiment.
FIG. 6 shows a processing procedure in which a part of the series of processing shown in FIG. 4 is changed, and the same steps as those shown in FIG. 4 are given the same step numbers. The series of processes shown in FIG. 6 is also executed when the process of S170 shown in FIG. 3, that is, when combustion control is started with the output suppressing ignition timing and the output suppressing valve timing set.

After starting this process, the control device 100 sequentially executes the above-described processes of S300, S310, and S320. Then, in the process of S320, when it is determined that the required ignition timing after the occurrence of the first explosion is on the advanced side of the output suppression ignition timing (S320: YES), the control device 100 controls the internal combustion engine 10 to The ignition timing is changed at the first rate of change HT1 (S500). This first rate of change HT1 is the rate of change of the ignition timing in the process of changing the ignition timing of the internal combustion engine 10 from the ignition timing for output suppression to the required ignition timing, and is smaller than the second rate of change HT2 described later. value. Also, the first rate of change HT1 is set to an optimum value for suppressing the rattling noise from the planetary gear mechanism 40 .

Next, the control device 100 determines whether or not the current second MG required torque TM2 exceeds "0 Nm" (S340).
When it is determined that the second MG required torque TM2 has exceeded "0 Nm" (S340: YES), the control device 100 changes the ignition timing of the internal combustion engine 10 at the second rate of change HT2 (S510). This second rate of change HT2 is also the rate of change of the ignition timing in the process of changing the ignition timing of the internal combustion engine 10 from the ignition timing for output suppression to the required ignition timing, and is a value larger than the first rate of change HT1. It has become. Also, the second rate of change HT2 is set to a value that allows the ignition timing to be changed to the required ignition timing as quickly as possible while suppressing the occurrence of a torque shock due to a rapid increase in the engine output. Then, the control device 100 ends this process.

Also, FIG. 7 shows a processing procedure in which a part of the series of processing shown in FIG. 5 is changed, and the same processing as each processing shown in FIG. 5 is given the same step number. The series of processes shown in FIG. 7 is also executed when the process of S170 shown in FIG. 3, that is, combustion control is started with the output suppressing ignition timing and the output suppressing valve timing set.

After starting this process, the control device 100 sequentially executes the above-described processes of S400, S410, and S420. Then, in the process of S420, when it is determined that the required valve timing after the occurrence of the first explosion is on the advance side of the output suppression valve timing (S420: YES), the control device 100 controls the intake valve 15 The valve timing is changed at the first rate of change HV1 (S600). This first rate of change HV1 is the rate of change of the valve timing in the process of changing the valve timing from the output suppression valve timing to the required valve timing, and is smaller than the second rate of change HV2 described later. there is Also, the first rate of change HV1 is set to an optimum value for suppressing the rattling noise from the planetary gear mechanism 40 .

Next, the control device 100 determines whether or not the current second MG required torque TM2 exceeds "0 Nm" (S440).
When it is determined that the second MG required torque TM2 has exceeded "0 Nm" (S440: YES), the control device 100 changes the valve timing of the intake valve 15 at the second rate of change HV2 (S610). This second rate of change HT2 is also the rate of change of the valve timing in the process of changing the valve timing from the output suppression valve timing to the required valve timing, and has a value greater than the first rate of change HV1. . Also, the second rate of change HV2 is set to a value that allows the valve timing to be changed to the required valve timing as quickly as possible while suppressing the occurrence of torque shock due to a rapid increase in the engine output. Then, the control device 100 ends this process.

Next, the operation and effects of this embodiment will be described.
(9) In the process of S320 shown in FIG. 6, when it is determined that the required ignition timing after the occurrence of the first explosion is on the advanced side of the output suppression ignition timing (S320: YES), the required If setting the ignition timing increases the engine output, the processes of S500, S340 and S510 are executed. As a result, until the second MG required torque TM2 exceeds "0 Nm", the ignition timing change rate in the process of changing the ignition timing from the output suppressing ignition timing to the required ignition timing remains at the first change rate HT1. By setting the ignition timing, the rate of change of the ignition timing becomes small, and the increase in the output torque of the internal combustion engine 10 becomes moderate. Therefore, the rapid increase in the output torque of the internal combustion engine 10 is suppressed when the second MG required torque TM2 straddles "0 Nm", thereby suppressing the rattling noise generated from the planetary gear mechanism 40.

(10) In the process of S420 shown in FIG. 7, when it is determined that the required valve timing after the occurrence of the first explosion is on the advance side of the output suppression valve timing (S320: YES), the required If the engine output is increased by setting the valve timing, the processes of S500, S340 and S510 are executed. As a result, until the second MG required torque TM2 exceeds "0 Nm", the valve timing change rate in the process of changing the valve timing from the output suppression valve timing to the required valve timing remains at the first change rate HV1. With this setting, the rate of change in valve timing is reduced and the increase in the output torque of the internal combustion engine 10 is moderated. Therefore, the rapid increase in the output torque of the internal combustion engine 10 is suppressed when the second MG required torque TM2 crosses over "0 Nm", and this also suppresses the rattling noise generated from the planetary gear mechanism 40.

It should be noted that each of the above-described embodiments can be implemented with the following modifications. Each of the above-described embodiments and the following modifications can be implemented in combination with each other within a technically consistent range.

・In the oil tightness determination process in S150 of FIG. The oil tightness determination process shown in S700 of FIG. 8 may be executed.

The oiltightness determination process in S700 of FIG. 8 is a process of determining that there is an oiltightness leak when the operation stop time TS of the internal combustion engine 10 before starting is equal to or greater than a specified threshold value TSref. As the threshold TSref, the internal combustion engine 10 stops operating for a long period of time to such an extent that there is a possibility that an unacceptable amount of fuel is leaking from the fuel injection valve 31 based on the fact that the operation stop time TS is equal to or greater than this threshold TSref. The magnitude of the value is set in advance so that it can be appropriately determined that the For example, as the threshold TSref, a time of about several hours is set.

According to such a modification, the following effects are obtained. That is, when the fuel injection valve 31 has an oil leak, fuel gradually leaks from the fuel injection valve 31 while the operation of the internal combustion engine 10 is stopped. . If motoring is performed with a large amount of leakage in this manner, unburned fuel may be discharged into the exhaust passage 21 before combustion is started. Therefore, when the amount of leaked fuel is large, the amount of unburned fuel discharged into the exhaust passage 21 can be suppressed by starting the combustion control as early as possible to burn the leaked fuel as early as possible. . In this regard, in the above modified example, as the oil tightness determination process in S700, when the operation stop time TS is equal to or greater than the threshold value TSref, a process of determining that there is an oil tightness leak is executed. Therefore, when the operation stop time TS is equal to or greater than the threshold value TSref and there is a possibility that the amount of fuel leaking from the fuel injection valve 31 is large, it is determined that there is an oil leak (S700: YES ), when the engine is started, combustion control is promptly started by executing the process of S190 without executing the negative pressure ensuring process after S160. Therefore, even if the fuel injection valve 31 has an oil leak, the amount of unburned fuel discharged into the exhaust passage 21 can be suppressed.

- In the second embodiment, the series of processes shown in FIGS. 4 and 5 are executed, but only the series of processes shown in FIG. 4 or only the series of processes shown in FIG. 5 may be executed. .
- Although the series of processes shown in FIGS. 6 and 7 are executed in the third embodiment, only the series of processes shown in FIG. 6 or only the series of processes shown in FIG. 7 may be executed. .

- Instead of executing the series of processes shown in FIG. 4 in the second embodiment, the series of processes shown in FIG. 6 may be executed in the third embodiment.
- Instead of executing the series of processes shown in FIG. 5 in the second embodiment, the series of processes shown in FIG. 7 may be executed in the third embodiment.

The fuel injection valve 31 may be an in-cylinder fuel injection valve that directly injects fuel into the cylinder of the internal combustion engine 10 .
The vehicle to which the first embodiment is applied is not limited to a hybrid vehicle, and may be a vehicle that has only an internal combustion engine as a prime mover of the vehicle and has an electric motor that drives the internal combustion engine.

- The control device 100 includes a CPU 110 and a memory 120, and is not limited to executing software processing. For example, a dedicated hardware circuit (eg, ASIC, etc.) that processes at least part of the software processing executed in each of the above embodiments may be provided. That is, the control device 100 may have any one of the following configurations (a) to (c). (a) A processing device that executes all of the above processes according to a program, and a program storage device such as a memory that stores the program. (b) A processing device and a program storage device for executing part of the above processing according to a program, and a dedicated hardware circuit for executing the remaining processing. (c) provide dedicated hardware circuitry to perform all of the above processing; Here, there may be a plurality of software processing circuits including a processing device and a program storage device, or a plurality of dedicated hardware circuits. That is, the processing may be performed by a processing circuit comprising at least one of one or more software processing circuits and one or more dedicated hardware circuits.

Reference Signs List 10 Internal combustion engine 11 Intake passage 12 Intake port 13 Surge tank 14 Throttle valve 15 Intake valve 16 Intake camshaft 17 Variable valve mechanism 21 Exhaust passage 22 Exhaust port 25 Exhaust valve 26 Exhaust camshaft 30 Combustion chamber 31 Fuel injection valve 32 Spark plug 33 Piston 34 Crankshaft 40 Planetary gear mechanism 41 Sun gear 42 Ring gear 44 Carrier 50 Reduction mechanism 60 Drive shaft 61 Differential gear 62 Drive wheel 71 First motor generator (first MG) 72 Second motor generator (second MG) 78 ... battery 80 ... crank angle sensor 81 ... cam angle sensor 82 ... air flow meter 83 ... water temperature sensor 84 ... fuel pressure sensor 85 ... vehicle speed sensor 86 ... accelerator position sensor 88 ... temperature sensor 100 ... control device , 110... Central processing unit (CPU), 120... Memory, 200... PCU, 500... Vehicle.

Claims (11)

A control device for an internal combustion engine motorized by an electric motor when there is a demand to start, comprising:
Both the state in which the amount of fuel leakage from the fuel injection valve provided in the internal combustion engine exceeds the allowable amount and the state in which the amount of fuel leakage from the fuel injection valve may exceed the allowable amount are both oil-tight. When it leaks,
While executing an oil tightness determination process for determining the presence or absence of the oil tightness leak,
When it is determined that there is no oil leak, the throttle of the internal combustion engine after the engine speed of the internal combustion engine, which increases due to the execution of the motoring in accordance with the start request, exceeds the resonance speed region of the internal combustion engine. Negative pressure ensuring processing is executed to adjust the opening degree of the throttle valve so that the inside of the intake pipe downstream of the valve is in a specified negative pressure state, and the execution of the negative pressure ensuring processing keeps the inside of the intake pipe in the negative pressure state. After that, the combustion control of the internal combustion engine is started, and when it is determined that there is the oil leak, the engine rotation speed of the internal combustion engine, which is increased by the execution of the motoring in accordance with the start request, is set to the above A control device for an internal combustion engine that executes start-up control for starting combustion control of the internal combustion engine without executing the negative pressure securing process after exceeding the resonance speed range. The starting control includes a condition that the temperature of the internal combustion engine is below a specified temperature, a condition that a temperature of a battery that drives the electric motor is below a specified temperature, and a charging rate of the battery that is below a specified charging rate. is equal to or less than the engine speed of the internal combustion engine before the engine rotation speed of the internal combustion engine, which increases due to the execution of the motoring in accordance with the start request, reaches the resonance speed region. The control device for an internal combustion engine according to claim 1, wherein a process for starting control is executed. The starting control is configured such that, when starting the internal combustion engine, the engine speed of the internal combustion engine is increased by executing the motoring according to the starting request if the required value of the output torque of the internal combustion engine is equal to or greater than a specified value. 3. The control device for an internal combustion engine according to claim 1, wherein after the speed exceeds the resonance speed range, a process for starting combustion control of the internal combustion engine is executed without executing the negative pressure securing process. The internal combustion engine includes a sensor that detects fuel pressure in the fuel injection valve,
In the oil-tightness determination process, the amount of decrease in the fuel pressure that has decreased while the operation of the internal combustion engine is stopped is calculated from the detection value of the sensor, and if the calculated amount of decrease is equal to or greater than a specified determination value, the oil-tightness determination process is performed. 4. The control device for an internal combustion engine according to any one of claims 1 to 3, which executes processing for determining that there is a leak. According to any one of claims 1 to 3, wherein the oil tightness determination process determines that there is an oil tightness leak when the operation stop time of the internal combustion engine before starting is equal to or longer than a specified determination value. Control device for an internal combustion engine as described. When the negative pressure securing process is executed, the ignition timing of the internal combustion engine when the combustion control is started is set for output suppression, which is the ignition timing at which the engine output is the lowest within the range where the air-fuel mixture can be combusted. The control device for an internal combustion engine according to any one of claims 1 to 5, wherein a process for setting ignition timing is executed. When the electric motor is the first electric motor and the electric motor for transmitting power to the drive shaft connected to the driving wheels of the vehicle is the second electric motor, the output shaft of the internal combustion engine is adapted to transmit the output of the internal combustion engine to the first electric motor. is connected to a planetary gear mechanism that distributes to the output shaft of and the drive shaft,
The required value of the output torque of the second electric motor when the combustion control is started is a torque lower than "0 Nm", and the required ignition timing after the occurrence of the initial explosion is on the advance side of the output suppression ignition timing. If it is the timing, executing a process of suspending the change of the ignition timing from the output suppressing ignition timing to the required ignition timing until the required value of the output torque of the second electric motor exceeds "0 Nm". 7. A control device for an internal combustion engine according to Item 6. When the electric motor is the first electric motor and the electric motor for transmitting power to the drive shaft connected to the driving wheels of the vehicle is the second electric motor, the output shaft of the internal combustion engine is adapted to transmit the output of the internal combustion engine to the first electric motor. is connected to a planetary gear mechanism that distributes to the output shaft of and the drive shaft,
The required value of the output torque of the second electric motor when the combustion control is started is a torque lower than "0 Nm", and the required ignition timing after the occurrence of the initial explosion is on the advance side of the output suppression ignition timing. If it is the timing, the change rate of the ignition timing in the process of changing the ignition timing from the output suppression ignition timing to the required ignition timing, and the requested value of the output torque of the second electric motor is "0 Nm". 7. The control device for an internal combustion engine according to claim 6, wherein the rate of change until the required value of the output torque of the second electric motor exceeds "0 Nm" is reduced. The internal combustion engine includes a variable valve mechanism that changes the valve timing of the intake valve,
When the negative pressure securing process is executed, the valve timing when the combustion control is started is set to the output suppression valve timing, which is the valve timing at which the engine output is the lowest within the range in which the air-fuel mixture can be combusted. The control device for an internal combustion engine according to any one of claims 1 to 6, wherein a setting process is executed. When the electric motor is the first electric motor and the electric motor for transmitting power to the drive shaft connected to the driving wheels of the vehicle is the second electric motor, the output shaft of the internal combustion engine is adapted to transmit the output of the internal combustion engine to the first electric motor. is connected to a power distribution mechanism that distributes power to the output shaft of and the drive shaft,
The required value of the output torque of the second electric motor when the combustion control is started is a torque lower than "0 Nm", and the required valve timing after the occurrence of the initial explosion is on the advance side of the output suppression valve timing. If it is the timing, executing a process of suspending the change of the valve timing from the output suppression valve timing to the required valve timing until the required value of the output torque of the second electric motor exceeds "0 Nm". 10. A control device for an internal combustion engine according to Item 9. When the electric motor is the first electric motor and the electric motor for transmitting power to the drive shaft connected to the driving wheels of the vehicle is the second electric motor, the output shaft of the internal combustion engine is adapted to transmit the output of the internal combustion engine to the first electric motor. is connected to a planetary gear mechanism that distributes to the output shaft of and the drive shaft,
The required value of the output torque of the second electric motor when the combustion control is started is a torque lower than "0 Nm", and the required valve timing after the occurrence of the initial explosion is on the advance side of the output suppression valve timing. In the case of the timing, the rate of change of the valve timing in the process of changing the valve timing from the output suppression valve timing to the required valve timing, and the required value of the output torque of the second electric motor is "0 Nm". 10. The control device for an internal combustion engine according to claim 9, wherein the rate of change until the required value of the output torque of the second electric motor exceeds "0 Nm" is reduced.

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