Control device for internal combustion engines

Abstract

To scavenge air inside a crank case even when an internal combustion engine is stopped.SOLUTION: An internal combustion engine 10 includes: an intake passage; a supercharger 24 which drives a compressor wheel 24C provided in the intake passage by a motor 24M; a flow rate adjustment valve 40 provided on a downstream side from the compressor wheel 24C in the intake passage; a first passage communicating the intake passage between the compressor wheel 24C and the flow rate adjustment valve 40 and the crank case 19; and a second passage communicating the intake passage on a downstream side from the flow rate adjustment valve 40 with the crank case 19. When the engine is stopped, the control device 100 executes scavenging control for driving the motor 24M with the flow rate adjustment valve 40 closed.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a control device for an internal combustion engine.

Background Art

[0002] For example, the internal combustion engine described in Patent Document 1 includes a flow regulating valve provided in an intake passage, a first passage that communicates the intake passage upstream of the flow regulating valve with a crankcase, and a second passage that communicates the intake passage downstream of the flow regulating valve with the crankcase. By utilizing the pressure in the intake passage generated during engine operation, blow-by gas in the crankcase is introduced into the intake passage to perform blow-by gas treatment for scavenging.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] By the way, if the state where the engine is stopped before the warm-up of the internal combustion engine is completed is repeated, the temperature in the crankcase does not rise. Therefore, condensed water derived from moisture contained in blow-by gas is likely to be generated in the crankcase. When condensed water is generated in the crankcase, there is a risk that the condensed water will mix with and accumulate in the lubricating oil stored in the oil pan, for example. Therefore, it is desirable to scavenge the inside of the crankcase even when the internal combustion engine is stopped. However, with the conventional configuration that utilizes the pressure in the intake passage generated during engine operation, it is difficult to scavenge the inside of the crankcase when the internal combustion engine is stopped.

Means for Solving the Problem

[0005] The control device for an internal combustion engine that solves the above problems is applied to an internal combustion engine having an intake passage, a supercharger that drives a compressor wheel provided in the intake passage with a motor, a flow control valve provided downstream of the compressor wheel in the intake passage, a first passage connecting the intake passage and the crankcase between the compressor wheel and the flow control valve, and a second passage connecting the intake passage downstream of the flow control valve and the crankcase. The control device is further configured to perform scavenging control that drives the motor with the flow control valve closed when the engine is stopped. [Effects of the Invention]

[0006] This internal combustion engine control system can scavenge the crankcase even when the engine is stopped. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic diagram showing the configuration of an internal combustion engine and drive system in one embodiment. [Figure 2] This flowchart shows the procedure for processing performed by the control device of the same embodiment. [Figure 3] This flowchart shows the procedure for the processing performed by the control device in a modified example of the same embodiment. [Figure 4] This flowchart shows the procedure for the processing performed by the control device in a modified example of the same embodiment. [Modes for carrying out the invention]

[0008] The following describes one embodiment of a control device for an internal combustion engine installed in a vehicle. <Configuration of the internal combustion engine and drivetrain> As shown in Figure 1, the internal combustion engine 10 comprises a cylinder block 11, a cylinder head 12, a head cover 13, and an oil pan 14. Inside the cylinder block 11 is a cylinder 16 in which a piston 15 is arranged to reciprocate.

[0009] The cylinder head 12 is provided with an intake port 30 for introducing intake air into the combustion chamber 17 of the internal combustion engine 10, and an exhaust port 70 for discharging exhaust gas from the combustion chamber 17. The intake port 30 is provided with an intake valve 81 that opens and closes the intake port 30. The intake valve 81 opens and closes in synchronization with the rotation of the crankshaft 18, which is the output shaft of the internal combustion engine 10. The drive system for the intake valve 81 is provided with an intake-side valve timing variable mechanism 85, which is a variable valve timing mechanism that changes the valve timing (opening and closing timing) of the intake valve 81.

[0010] The exhaust port 70 is provided with an exhaust valve 82 that opens and closes the exhaust port 70. The exhaust valve 82 opens and closes in synchronization with the rotation of the crankshaft 18. The drive system for the exhaust valve 82 is provided with an exhaust-side valve timing variable mechanism 86, which is a variable valve timing mechanism that changes the valve timing (opening and closing timing) of the exhaust valve 82.

[0011] The cylinder head 12 is equipped with a port injection valve 83 for injecting hydrogen gas, which is engine fuel, into the intake port 30, an in-cylinder injection valve 84 for directly injecting hydrogen gas, which is engine fuel, into the combustion chamber 17, and a spark plug (not shown).

[0012] A crankcase 19 is provided at the bottom of the cylinder block 11, which houses the crankshaft 18, the output shaft of the internal combustion engine 10. An oil pan 14 for storing lubricating oil is provided at the bottom of the crankcase 19.

[0013] An intake manifold 29 equipped with a surge tank 60 is connected upstream of the intake port 30, and an intake pipe 20 is connected upstream of the surge tank 60. The intake pipe 20, surge tank 60, and intake manifold 29 constitute the intake passage of the internal combustion engine 10.

[0014] An air cleaner 21, a compressor wheel 24C of a supercharger 24, an intercooler 27, a throttle valve 28, and a flow rate adjustment valve 40 are installed in the intake pipe 20 in order from the upstream side thereof.

[0015] The air cleaner 21 filters intake air taken into the intake pipe 20. The supercharger 24 is a device that supercharges air in the intake pipe 20, and the compressor wheel 24C is rotationally driven by an electric motor 24M.

[0016] The intercooler 27 cools the air after passing through the compressor wheel 24C. The throttle valve 28 is a valve that adjusts the intake air amount of the internal combustion engine 10, and the opening degree of the valve is changed when a butterfly valve is rotated by an electric motor.

[0017] The flow rate adjustment valve 40 is a valve that adjusts the flow rate of blow-by gas introduced from the crankcase 19 into the intake passage, and the opening degree of the valve is changed by an electric motor. Although the flow rate adjustment valve 40 of the present embodiment has the same valve structure as the throttle valve 28, it may have a different valve structure.

[0018] An exhaust passage 90 is connected downstream of the exhaust port 70. The internal combustion engine 10 is provided with a blow-by gas treatment device that treats gas that has leaked from the combustion chamber 17 into the crankcase 19 during a compression stroke or a combustion stroke, that is, so-called blow-by gas.

[0019] The blow-by gas processing device includes a fresh air introduction path 37 for introducing fresh air into the crankcase 19 to perform scavenging. One end of the two ends of the fresh air introduction path 37 is connected to the intake pipe 20 between the throttle valve 28 and the flow rate adjustment valve 40. The fresh air introduction path 37 passes through the head cover 13, runs through the interior of the cylinder head 12 and the cylinder block 11, and is connected to the crankcase 19. A separator 38, which is an oil separator installed in the head cover 13, is provided midway along the fresh air introduction path 37. The fresh air introduction path 37 and the separator 38 constitute a first passage that communicates the intake passage between the compressor wheel 24C and the flow rate adjustment valve 40 with the crankcase 19.

[0020] The blow-by gas processing device includes a suction path 32 for guiding the blow-by gas in the crankcase 19 to the separator 31, which is an oil separator provided on the head cover 13. A distal end of the suction path 32 connected to the separator 31 opens into the crankcase 19. Note that the separator 31 may be provided midway along the suction path 32.

[0021] The separator 31 is connected to the surge tank 60 via a PCV passage 35. The suction path 32, the separator 31, and the PCV passage 35 constitute a second passage that communicates the intake passage downstream of the flow rate adjustment valve 40 with the crankcase 19.

[0022] Fresh air is introduced into the crankcase 19 via the fresh air introduction path 37. Furthermore, when the opening degree of the flow rate adjustment valve 40 is adjusted to be reduced, the pressure on the downstream side of the flow rate adjustment valve 40 in the intake pipe 20 decreases. When the pressure on the downstream side of the flow rate adjustment valve 40 decreases, the blow-by gas in the crankcase 19 is sucked into the intake pipe 20 together with the fresh air via the suction path 32. The blow-by gas sucked into the intake pipe 20 is sent to the combustion chamber 17 together with the intake air and is combusted.

[0023] The crankshaft 18 is mechanically connected to the carrier C of the planetary gear mechanism 300, which constitutes the power split device. The sun gear S of the planetary gear mechanism 300 is mechanically connected to the rotating shaft 310a of the first motor generator 310. The ring gear R of the planetary gear mechanism 300 is mechanically connected to the rotating shaft 320a of the second motor generator 320 and the drive wheel 400. An AC voltage is applied to the terminals of the first motor generator 310 by the inverter 330. An AC voltage is also applied to the terminals of the second motor generator 320 by the inverter 340. Thus, the vehicle of this embodiment is equipped with a hybrid system that includes an internal combustion engine 10 and a motor generator as prime movers.

[0024] The control device 100 controls the internal combustion engine 10. The control device 100 operates various controllable components, including the throttle valve 28, flow control valve 40, port injection valve 83 and in-cylinder injection valve 84, spark plug, intake valve timing variable mechanism 85, exhaust valve timing variable mechanism 86, and the motor 24M of the supercharger 24. The control device 100 also operates the inverter 330 to control the first motor generator 310. Furthermore, the control device 100 operates the inverter 340 to control the second motor generator 320.

[0025] The control device 100 includes a CPU 110 for arithmetic processing and a memory 120 that stores control programs and data. The control device 100 performs various control-related processes by having the CPU 110 execute the programs stored in the memory 120. Although not shown in the diagram, the control device 100 is composed of multiple control units, including a control unit for the internal combustion engine and control units for the first motor generator 310 and the second motor generator 320.

[0026] The control device 100 receives detection signals from various sensors. For example, the control device 100 receives detection signals from the air flow meter 22, which detects the intake air volume GA, and from the throttle sensor 25, which detects the throttle opening TA, which is the opening degree of the throttle valve 28. The control device 100 also receives detection signals from the valve opening sensor 26, which detects the valve opening BA, which is the opening degree of the flow control valve 40. The control device 100 also receives detection signals from the crank angle sensor 51, which detects the rotation angle (crank angle) of the crankshaft 18 in order to calculate the engine rotation speed NE. The control device 100 also receives detection signals from the accelerator pedal operation amount sensor 52, which detects the accelerator pedal operation amount ACP, which is the amount the accelerator pedal is operated. The control device 100 also receives detection signals from the coolant temperature sensor 53, which detects the coolant temperature THW, which is the temperature of the coolant in the internal combustion engine 10, and from the oil temperature sensor 54, which detects the oil temperature THO, which is the temperature of the lubricating oil in the internal combustion engine 10. Furthermore, the control device 100 receives a detection signal from a vehicle speed sensor 55 that detects the vehicle speed SP of the vehicle equipped with the internal combustion engine 10. The control device 100 also receives a detection signal from an intake pressure sensor 56 that detects the intake pressure PIM, which is the pressure inside the surge tank 60. The control device 100 also receives an output signal Sm1 from a first rotation angle sensor 350 that detects the rotation angle of the first motor generator 310. The control device 100 also receives an output signal Sm2 from a second rotation angle sensor 360 that detects the rotation angle of the second motor generator 320.

[0027] The control device 100 calculates the engine load ratio KL based on the engine rotational speed NE and the intake air volume GA. The engine load ratio KL is a parameter that determines the amount of air filled into the combustion chamber 17, and is the ratio of the amount of air inflow per combustion cycle per cylinder to the standard amount of incoming air. The standard amount of incoming air is set variably according to the engine rotational speed NE.

[0028] The control device 100 calculates the required torque for the vehicle's operation based on the accelerator pedal input ACP and the vehicle speed SP. The control device 100 then controls the required output Pe of the internal combustion engine 10 and the output torques of the first motor generator 310 and the second motor generator 320 to meet the vehicle's required torque. For example, if the required output Pe of the internal combustion engine 10 is "0", the operation of the internal combustion engine 10 is stopped and EV driving is performed using the output torque of the second motor generator 320.

[0029] Hydrogen gas, which is used as engine fuel, has a wider range of combustible mixtures compared to gasoline, and can burn even in lean mixtures. Therefore, the control device 100 controls the output of the internal combustion engine 10 as follows.

[0030] In other words, when the requested output Pe is large, the control device 100 performs control to make the air-fuel ratio of the mixture smaller than when the requested output Pe is small. More specifically, the control device 100 basically maintains the throttle valve 28 at an opening degree greater than a predetermined value, for example, an opening degree near full open. Then, it sets the requested injection amount Qd such that the larger the requested output Pe, the greater the requested injection amount Qd. The requested injection amount Qd is the target value of the fuel injected from the port injection valve 83 and the in-cylinder injection valve 84. Then, the control device 100 controls the port injection valve 83 and the in-cylinder injection valve 84 to obtain the requested injection amount Qd. In this way, the output of the internal combustion engine 10 is adjusted by changing the air-fuel ratio of the mixture through adjustment of the fuel injection amount.

[0031] Furthermore, the control device 100 calculates the target valve timing for the intake valve 81 and exhaust valve 82 based on the engine rotational speed NE and engine load ratio KL. Then, based on the target valve timing, it performs drive control of the intake valve timing variable mechanism 85 and the exhaust valve timing variable mechanism 86.

[0032] Furthermore, when the engine is stopped, the control device 100 calculates target valve timings for the intake valve 81 and exhaust valve 82 so that valve overlap is formed, where a portion of the opening period of the intake valve 81 and a portion of the opening period of the exhaust valve 82 overlap. Then, when the engine is stopped, the control device 100 controls the drive of the intake valve timing variable mechanism 85 and the exhaust valve timing variable mechanism 86 so that valve overlap is formed.

[0033] Furthermore, the control device 100 calculates a target boost pressure PTCp based on the engine rotational speed NE and engine load ratio KL. Then, it controls the drive of the motor 24M based on the target boost pressure PTCp, thereby controlling the boost pressure of the turbocharger 24.

[0034] <Scavenging control> Since the engine fuel of the internal combustion engine 10 is hydrogen gas, which is a gaseous fuel, the proportion of hydrogen molecules in the fuel is higher compared to liquid fuels such as gasoline. Therefore, the amount of water contained in the blow-by gas is higher than that of liquid fuels. If the engine is repeatedly stopped before the internal combustion engine 10 has finished warming up, the temperature inside the crankcase 19 will not rise. As a result, condensed water derived from the water contained in the blow-by gas is more likely to form inside the crankcase 19. If condensed water forms inside the crankcase 19, there is a risk that it may mix with and accumulate in the lubricating oil stored in the oil pan 14, for example.

[0035] Therefore, the control device 100 performs the process shown in Figure 2 so that it can scavenge the inside of the crankcase 19 not only while the internal combustion engine 10 is running, but also when it is stopped.

[0036] Figure 2 shows the procedure for the processing performed by the control device 100. The processing shown in Figure 2 is realized by the CPU 110 executing a program stored in the memory 120 of the control device 100. The processing shown in Figure 2 starts when the control device 100 determines that the operation of the internal combustion engine 10 has stopped. In the following, the step number of each process is represented by a number preceded by "S".

[0037] In the series of processes shown in Figure 2, the control device 100 determines whether the internal combustion engine 10 is in a low-temperature environment (S110). In process S110, the control device 100 determines that the internal combustion engine 10 is in a low-temperature environment if the temperature of the internal combustion engine 10 at the time of engine shutdown is below a predetermined threshold. Possible values ​​for indicating the temperature of the internal combustion engine 10 include, for example, the coolant temperature THW and the oil temperature THO. Alternatively, the temperature of the internal combustion engine 10 may be estimated based on the operating time of the internal combustion engine 10 before shutdown.

[0038] In the process of S110, if it is determined that the internal combustion engine 10 is in a low-temperature environment (S110: YES), the control device 100 adjusts the valve opening (S120). In the process of S120, the control device 100 adjusts the opening of the throttle valve 28 so that it is fully open, and adjusts the opening of the flow control valve 40 so that it is fully closed.

[0039] Next, the control device 100 drives the supercharger 24 by rotating the motor 24M (S130). As a result of the execution of processes S120 and S130, when the engine is stopped, scavenging control is performed to drive the motor 24M of the supercharger 24 with the flow control valve 40 closed.

[0040] Next, the control device 100 acquires the intake pressure PIM detected during the execution of scavenging control and determines whether the acquired intake pressure PIM is greater than or equal to a predetermined determination value PIMref (S140). The determination value PIMref is the minimum value of the intake pressure PIM measured when the valve overlap described above does not occur during the execution of scavenging control, and is a predetermined value.

[0041] In the process of S140, if it is determined that the intake pressure PIM is equal to or greater than the determination value PIMref (S140: YES), the control device 100 starts motoring control to drive the first motor generator 310 and rotate the crankshaft 18 (S150).

[0042] After executing the process in S150, the control device 100 determines whether or not the intake pressure PIM has decreased (S160). In the process of S160, the control device 100 acquires the intake pressure PIM. If the intake pressure PIM acquired in the process of S160 is lower than or equal to a predetermined value compared to the intake pressure PIM acquired in the process of S140, the control device 100 determines that the intake pressure PIM has decreased.

[0043] Then, the control device 100 repeatedly executes the processes of S150 and S160 until it is determined that the intake pressure PIM has decreased during the S160 process. If it is determined in the process of S160 that the intake pressure PIM has decreased (S160: YES), the control device 100 terminates the motoring control by stopping the drive of the first motor generator 310 and stopping the rotation of the crankshaft 18 (S170).

[0044] If the process in S140 is deemed negative, or if the process in S170 is completed, the control device 100 executes the process in S180. In the process of S180, the control device 100 determines whether the operating time T of the supercharger 24 is greater than or equal to a predetermined judgment value Tref. The operating time T is the elapsed time since the operation of the supercharger 24 was started in the process of S130, and is measured by the control device 100. The judgment value Tref is the minimum operating time of the supercharger 24 required to perform scavenging in the crankcase 19, and is a predetermined value.

[0045] Then, the control device 100 repeatedly executes the process of S180 until it is determined that the drive time T is equal to or greater than the determination value Tref during the process of S180. If, during the process in S180, it is determined that the drive time T is greater than or equal to the determination value Tref (S180: YES), the control device 100 stops the drive of the supercharger 24 by stopping the rotation of the motor 24M (S190). Then, the control device 100 terminates this process.

[0046] <Operation and Effects of This Embodiment> (1) When the engine is stopped, scavenging control is performed by driving the motor 24M of the supercharger 24 with the flow control valve 40 closed. When the motor 24M of the supercharger 24 is driven, fresh air flows into the crankcase 19 through the first passage. The fresh air that flows into the crankcase 19 flows into the intake passage through the second passage along with the blow-by gas inside the crankcase 19, thus scavenging the inside of the crankcase 19. Therefore, even when the internal combustion engine 10 is stopped, the inside of the crankcase 19 can be scavenged.

[0047] (2) When scavenging control is being performed, if both the intake valve 81 and the exhaust valve 82 are open, that is, valve overlap occurs, the blow-by gas that has flowed into the intake passage flows out into the exhaust passage 90 of the internal combustion engine 10. As a result, scavenging in the crankcase 19 is facilitated. Here, when valve overlap does not occur, the fresh air and blow-by gas that have flowed into the intake passage do not flow out into the exhaust passage 90, so the intake pressure in the part downstream of the flow control valve 40 increases. In this embodiment, if the intake pressure PIM detected during the execution of scavenging control is greater than or equal to the determination value PIMref and it can be determined that valve overlap does not occur, the control device 100 performs motoring control to rotate the crankshaft 18 of the internal combustion engine 10. When the crankshaft 18 rotates, the intake valve 81 and the exhaust valve 82 are driven and valve overlap occurs. As a result, scavenging in the crankcase 19 can be performed more effectively.

[0048] (3) When the temperature of the internal combustion engine 10 is below a predetermined threshold when the engine is stopped, and it is determined that the internal combustion engine 10 is in a low-temperature environment (S110: YES in Figure 2), the control device 100 performs scavenging control. Therefore, when the temperature of the internal combustion engine 10 is above a predetermined threshold when the engine is stopped, and condensation is unlikely to occur in the crankcase 19, scavenging control is not performed. Thus, unnecessary power consumption caused by driving the motor 24M of the supercharger 24 can be suppressed.

[0049] <Example of changes> This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0050] If scavenging control is performed immediately upon engine shutdown, the motor noise of the supercharger 24 may be audible to the vehicle's occupants despite the engine shutdown, potentially causing discomfort. Therefore, scavenging control may be performed after a predetermined time has elapsed since engine shutdown. In this case, scavenging control is performed when the vehicle's occupants are likely to have dismounted and moved away from the vehicle. This reduces the likelihood of causing discomfort to the vehicle's occupants as described above.

[0051] Figure 3 shows some of the processing steps that the control device 100 performs to implement this modification example. The processing shown in the figure also starts when the control device 100 determines that the operation of the internal combustion engine 10 has stopped.

[0052] As shown in Figure 3, the control device 100 executes the process in S200 before performing the process in S110 shown in Figure 2. In the process of S200, the control device 100 determines whether a predetermined time has elapsed since the engine stopped. The predetermined time can be set to, for example, the time required from the time the engine stops until the occupants of the vehicle move a certain distance away from the vehicle. The control device 100 then repeatedly executes the process of S200 until it determines that the predetermined time has elapsed since the engine stopped.

[0053] In the process of S200, if it is determined that a predetermined time has elapsed since the engine stopped (S200: YES), the control device 100 executes the processes from S110 onwards as described above. The scavenging control described above may be performed multiple times with a predetermined pause in between. In this case, the first scavenging control mainly cleans the crankcase 19. In subsequent scavenging control attempts, fresh air is introduced into the crankcase 19, which dries out any condensed water adhering to the cylinder bore and the inner wall of the crankcase 19. The number of times the scavenging control is performed can be set as appropriate.

[0054] Figure 4 shows some of the processing steps that the control device 100 performs to implement this modification example. As shown in the figure, the control device 100 performs the processing S190 shown in Figure 2, and then performs the processing steps S300 to S340.

[0055] In the process of S300, the control device 100 determines whether the stop time TS of the supercharger 24 is greater than or equal to a predetermined judgment value TSref. The stop time TS is the elapsed time since the drive of the supercharger 24 was stopped in the process of S190, and is measured by the control device 100. The judgment value TSref is a predetermined value that is useful for drying the inside of the crankcase 19 by stopping the drive of the supercharger 24.

[0056] Then, in the process of S300, the control device 100 repeatedly executes the process of S300 until it is determined that the stop time TS is equal to or greater than the determination value TSref. If, during the process in S300, it is determined that the stop time TS is equal to or greater than the determination value TSref (S300: YES), the control device 100 drives the supercharger 24 by rotating the motor 24M (S310).

[0057] Next, the control device 100 determines whether the operating time T of the supercharger 24 is greater than or equal to a predetermined determination value Tref (S320). The operating time T is the elapsed time since the operation of the supercharger 24 was started in the process of S310, and is measured by the control device 100. The determination value Tref is the operating time of the supercharger 24 that is beneficial for drying the inside of the crankcase 19, and is a predetermined value.

[0058] Then, in the process of S320, the control device 100 repeatedly executes the processes of S310 and S320 until it is determined that the drive time T is equal to or greater than the determination value Tref. If, during the process in S320, it is determined that the drive time T is equal to or greater than the determination value Tref (S320: YES), the control device 100 stops the drive of the supercharger 24 by stopping the rotation of the motor 24M (S340). Then, the control device 100 terminates this process.

[0059] In the above embodiment, the feasibility of motoring control was determined based on the intake pressure PIM. Alternatively, the determination of whether or not motoring control can be performed based on the intake pressure PIM may be omitted. Furthermore, motoring control may be performed from the start to the end of the drive of the supercharger 24.

[0060] • Although the suction passage 32 was connected to the surge tank 60, the connection point may be changed as appropriate, as long as it is located downstream of the flow control valve 40 in the intake passage. The internal combustion engine 10 may be equipped with either a port injection valve 83 or an in-cylinder injection valve 84.

[0061] The internal combustion engine 10 may be equipped with either an intake valve timing variable mechanism 85 or an exhaust valve timing variable mechanism 86. A PCV valve may be provided in the PCV passage 35 that opens when the pressure in the surge tank 60 becomes lower than the pressure in the separator 31, allowing blow-by gas to flow from the separator 31 to the surge tank 60.

[0062] The internal combustion engine 10 may be equipped with an EGR device that recirculates exhaust gases into the intake passage. • Gaseous fuels such as LPG or CNG may be used as engine fuel for the internal combustion engine 10. • The internal combustion engine 10 may use gasoline, diesel fuel, or other liquid fuels such as alcohol fuel as engine fuel.

[0063] • The vehicle's hybrid system is not limited to the one shown in Figure 1; other hybrid systems may also be used. The number of motor generators equipped in the vehicle can be changed as needed.

[0064] The vehicle may be equipped only with an internal combustion engine 10 as the prime mover. In this modified example, the motoring control described above can be implemented, for example, by driving a starter motor that rotates the crankshaft 18 when the engine is started.

[0065] The control device 100 includes a CPU 110 and a memory 120, and executes software processing. However, this is merely an example. The control device 100 may include, for example, a dedicated hardware circuit (e.g., an ASIC) that processes at least a portion of the software processing performed in the above embodiment. That is, the control device 100 may have any of the following configurations (a) to (c): (a) A processing unit that executes all of the above processing according to a program, and a program storage device such as a memory that stores the program. (b) A processing unit and a program storage device that execute a portion of the above processing according to a program, and a dedicated hardware circuit that executes the remaining processing. (c) A dedicated hardware circuit that executes all of the above processing. Here, there may be multiple software circuits with processing units and program storage devices, and multiple dedicated hardware circuits. That is, the above processing may be executed by a processing circuit that includes at least one of one or more software circuits and one or more dedicated hardware circuits. The program storage device, i.e., computer-readable media, includes any available media that can be accessed by a general-purpose or dedicated computer. [Explanation of symbols]

[0066] 10...Internal combustion engine, 11...Cylinder block, 12...Cylinder head, 13...Head cover, 14...Oil pan, 15...Piston, 16...Cylinder, 17...Combustion chamber, 18...Crankshaft, 19...Crankcase, 20...Intake pipe, 21...Air cleaner, 22...Air flow meter, 24...Supercharger, 24C...Compressor wheel, 24M...Motor, 25...Throttle sensor, 26...Valve opening sensor, 27...Intercooler, 28...Throttle valve, 29...Intake manifold, 30...Intake port, 31...Separator, 32...Suction passage, 35...PCV passage, 37...Fresh air intake passage, 38...Separator, 40...Flow control valve, 51...Crank angle sensor, 52...Act Cell operation amount sensor, 53...Water temperature sensor, 54...Oil temperature sensor, 55...Vehicle speed sensor, 56...Intake pressure sensor, 60...Surge tank, 70...Exhaust port, 81...Intake valve, 82...Exhaust valve, 83...Port injection valve, 84...In-cylinder injection valve, 85...Intake side valve timing variable mechanism, 86...Exhaust side valve timing variable mechanism, 90...Exhaust passage, 100...Control device, 110...CPU, 120...Memory, 300...Planetary gear mechanism, 310...First motor generator, 310a...Rotating shaft, 320...Second motor generator, 320a...Rotating shaft, 330...Inverter, 340...Inverter, 350...First rotation angle sensor, 360...Second rotation angle sensor, 400...Drive wheel

Claims

1. A control device for an internal combustion engine, The aforementioned internal combustion engine is The system is configured such that a valve overlap occurs when the engine is stopped, where a portion of the opening period of the intake valve that opens and closes the intake port of the internal combustion engine overlaps with a portion of the opening period of the exhaust valve that opens and closes the exhaust port of the internal combustion engine. The system includes an intake passage, a supercharger that drives a compressor wheel provided in the intake passage with a motor, a flow control valve provided downstream of the compressor wheel in the intake passage, a first passage connecting the intake passage and the crankcase between the compressor wheel and the flow control valve, a second passage connecting the intake passage downstream of the flow control valve and the crankcase, and an intake pressure sensor configured to detect the intake pressure at a point downstream of the flow control valve in the intake passage. The control device includes a processing circuit configured to perform scavenging control, which drives the motor with the flow control valve closed when the engine is stopped. The processing circuit is configured to perform motoring control to rotate the crankshaft of the internal combustion engine if the intake pressure detected during the execution of the scavenging control is equal to or greater than a predetermined determination value. Control device for internal combustion engines.

2. The processing circuit is configured to execute the scavenging control when the temperature of the internal combustion engine is below a predetermined threshold when the engine is stopped. A control device for an internal combustion engine according to claim 1.

3. The processing circuit is configured to execute the scavenging control after a predetermined time has elapsed since the engine was stopped. A control device for an internal combustion engine according to claim 1.

4. The processing circuit is configured to execute the scavenging control multiple times with a predetermined pause period in between. A control device for an internal combustion engine according to claim 1.

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