Control device of internal combustion engine

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 rate adjustment valve provided in an intake passage, a first passage that communicates the intake passage upstream of the flow rate adjustment valve with a crankcase, and a second passage that communicates the intake passage downstream of the flow rate adjustment valve with the crankcase. Then, 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

Problems to be Solved by the Invention

[0004] By the way, when the state where the engine stop is repeated before the warm-up of the internal combustion engine is completed, the temperature in the crankcase does not rise. Therefore, condensed water derived from the moisture contained in the blow-by gas is likely to be generated in the crankcase. When condensed water is generated in the crankcase, for example, there is a risk that the condensed water will mix into and accumulate in the lubricating oil stored in the oil pan. Therefore, it is desirable to scavenge 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 crankcase when the internal combustion engine is stopped.

Means for Solving the Problems

[0005] The control device for an internal combustion engine that solves the above problems includes an intake passage, a supercharger that drives a compressor wheel provided in the intake passage with a motor, a flow rate adjustment valve provided downstream of the compressor wheel in the intake passage, a first passage that communicates the intake passage between the compressor wheel and the flow rate adjustment valve and the crankcase, and a second passage that communicates the intake passage downstream of the flow rate adjustment valve and the crankcase, and is applied to an internal combustion engine having the same. And the control device includes a processing circuit configured to execute scavenging control for driving the motor with the flow rate adjustment valve closed when the engine is stopped.

Effect of the Invention

[0006] This control device for an internal combustion engine can scavenge the inside of the crankcase even when the internal combustion engine is stopped.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0008] Hereinafter, an embodiment in which a control device for an internal combustion engine mounted on a vehicle is embodied will be described. <Configuration of Internal Combustion Engine and Drive System> As shown in FIG. 1, the internal combustion engine 10 includes a cylinder block 11, a cylinder head 12, a head cover 13, and an oil pan 14. A cylinder 16 in which a piston 15 is reciprocally arranged is provided in the cylinder block 11.

[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 for opening and closing 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. In the drive system of the intake valve 81, an intake-side variable valve timing mechanism 85 which is a variable valve mechanism for changing the valve timing (opening and closing timing) of the intake valve 81 is provided.

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

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

[0012] A crankcase 19 in which a crankshaft 18 which is the output shaft of the internal combustion engine 10 is housed is provided at the lower part of the cylinder block 11. An oil pan 14 for storing lubricating oil is provided at the lower part of the crankcase 19.

[0013] An intake manifold 29 having 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, the surge tank 60, and the intake manifold 29 constitute the intake passage of the internal combustion engine 10.

[0014] In the intake pipe 20, 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 order from the upstream side.

[0015] The air cleaner 21 filters the intake air taken into the intake pipe 20. The supercharger 24 is a device that supercharges the 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 it passes 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 by rotating a butterfly valve 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. The flow rate adjustment valve 40 of the present embodiment has the same valve structure as the throttle valve 28, but a different valve structure may also be used.

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

[0019] The blow-by gas treatment device is provided with a fresh air introduction passage 37 for introducing fresh air into the crankcase 19 for scavenging. One end of both ends of the fresh air introduction passage 37 is connected to the intake pipe 20 between the throttle valve 28 and the flow rate adjustment valve 40. The fresh air introduction passage 37 passes through the head cover 13, passes through the inside of the cylinder head 12 and the cylinder block 11, and is connected to the crankcase 19. In the middle of the fresh air introduction passage 37, a separator 38 which is an oil separator installed in the head cover 13 is provided. The fresh air introduction passage 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 and the crankcase 19.

[0020] The blow-by gas treatment device is provided with a suction passage 32 for guiding the blow-by gas in the crankcase 19 to a separator 31 which is an oil separator provided in the head cover 13. The end of the suction passage 32 connected to the separator 31 opens into the crankcase 19. Note that the separator 31 may be provided in the middle of the suction passage 32.

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

[0022] Fresh air is introduced into the crankcase 19 through the fresh air introduction passage 37. Further, 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 through the suction passage 32 together with the fresh air. The blow-by gas sucked into the intake pipe 20 is sent to the combustion chamber 17 together with the intake air and burned.

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

[0024] The control device 100 controls the internal combustion engine 10. Then, the control device 100 operates various operation target devices such as the throttle valve 28, the flow rate adjustment valve 40, the port injection valve 83, the in-cylinder injection valve 84, the ignition plug, the intake-side valve timing variable mechanism 85, the exhaust-side valve timing variable mechanism 86, and the motor 24M of the supercharger 24. Also, the control device 100 operates the inverter 330 to control the first motor generator 310. Further, the control device 100 operates the inverter 340 to control the second motor generator 320.

[0025] The control device 100 includes a CPU 110 that performs arithmetic processing, a memory 120 in which control programs and data are stored, and the like. Then, the control device 100 executes processes related to various controls by the CPU 110 executing the programs stored in the memory 120. Although not shown in the figure, the control device 100 is composed of a plurality of control units such as a control unit for the internal combustion engine and control units for the first motor generator 310 and the second motor generator 320.

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

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

[0028] The control device 100 calculates the required torque necessary for the vehicle to travel based on the accelerator operation amount ACP and the vehicle speed SP. Then, the control device 100 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 so as to satisfy the required torque of the vehicle. For example, when the required output Pe of the internal combustion engine 10 is "0", an EV driving is performed in which the operation of the internal combustion engine 10 is stopped and the vehicle travels with the output torque of the second motor generator 320.

[0029] Hydrogen gas, which is the engine fuel, has a wider range of combustible mixtures compared to gasoline and can burn even with a lean mixture. Therefore, the control device 100 performs the following output control of the internal combustion engine 10.

[0030] That is, when the required output Pe is large, the control device 100 executes control to make the air-fuel ratio of the mixture smaller than when the required output Pe is small. More specifically, the control device 100 basically maintains the throttle valve 28 at an opening degree equal to or greater than a default value, for example, an opening degree near full opening. Then, the required injection amount Qd is set so that the required injection amount Qd increases as the required output Pe increases. The required injection amount Qd is the target value of the fuel injected from the port injection valve 83 and the in-cylinder injection valve 84. And the control device 100 controls the port injection valve 83 and the in-cylinder injection valve 84 so that the required injection amount Qd is obtained. In this way, in the internal combustion engine 10, the output is adjusted by changing the air-fuel ratio of the mixture through the adjustment of the fuel injection amount.

[0031] In addition, the control device 100 calculates the target valve timing of the intake valve 81 and the exhaust valve 82 based on the engine rotation speed NE, the engine load factor KL, etc. Then, based on the target valve timing, etc., drive control of the intake-side valve timing variable mechanism 85 and the exhaust-side valve timing variable mechanism 86 is performed.

[0032] Also, when the engine is stopped, the control device 100 calculates the target valve timings of the intake valve 81 and the exhaust valve 82 such that valve overlap is formed where a part of the opening period of the intake valve 81 overlaps with a part of the opening period of the exhaust valve 82. Then, when the engine is stopped, the control device 100 performs drive control of the intake-side valve timing variable mechanism 85 and the exhaust-side valve timing variable mechanism 86 so that valve overlap is formed.

[0033] Further, the control device 100 calculates a target supercharging pressure PTCp based on the engine rotational speed NE, the engine load factor KL, etc. Then, the control device 100 performs supercharging pressure control of the supercharger 24 by controlling the drive of the motor 24M based on the target supercharging pressure PTCp, etc.

[0034] <Scavenging control> Since the engine fuel of the internal combustion engine 10 is gaseous fuel, hydrogen gas, the proportion of hydrogen molecules in the fuel is larger compared to the case of gasoline, etc., which is liquid fuel. Therefore, the amount of moisture contained in the blow-by gas becomes larger than that of liquid fuel. Here, if the state where the engine is stopped before the warm-up of the internal combustion engine 10 is completed is repeated, the temperature in the crankcase 19 does not rise. Therefore, condensed water derived from the moisture contained in the blow-by gas is likely to be generated in the crankcase 19. When condensed water is generated in the crankcase 19, for example, there is a risk that the condensed water will mix into and accumulate in the lubricating oil stored in the oil pan 14.

[0035] Therefore, the control device 100 executes the process shown in FIG. 2 so that the inside of the crankcase 19 can be scavenged not only during the operation of the internal combustion engine 10 but also when the operation is stopped.

[0036] FIG. 2 shows the procedure of the process executed by the control device 100. The process shown in FIG. 2 is realized by the CPU 110 executing a program stored in the memory 120 of the control device 100. Note that the process shown in FIG. 2 is started when the control device 100 determines that the operation of the internal combustion engine 10 has stopped. Also, hereinafter, the step numbers of each process are represented by numbers with "S" attached at the beginning.

[0037] In the series of processes shown in FIG. 2, the control device 100 determines whether the internal combustion engine 10 is in a low-temperature environment (S110). In the process of S110, when the temperature of the internal combustion engine 10 at the time of engine stop is equal to or lower than a predetermined threshold value, the control device 100 determines that the internal combustion engine 10 is in a low-temperature environment. As a value indicating the temperature of the internal combustion engine 10, for example, the coolant temperature THW, the oil temperature THO, etc. can be adopted. Also, the temperature of the internal combustion engine 10 may be estimated based on the operating time of the internal combustion engine 10 before operation stop, etc.

[0038] In the process of S110, when 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 degree (S120). In the process of S120, the control device 100 adjusts the opening degree of the throttle valve 28 so as to be in the fully open state and adjusts the opening degree of the flow rate adjustment valve 40 so as to be in the fully closed state.

[0039] Next, the control device 100 drives the supercharger 24 by rotating the motor 24M (S130). By executing the processes of S120 and S130, scavenging control is executed in which the motor 24M of the supercharger 24 is driven with the flow rate adjustment valve 40 closed when the engine stop is performed.

[0040] Next, the control device 100 acquires the intake pressure PIM detected during the execution of the scavenging control, and determines whether the acquired intake pressure PIM is equal to or higher than 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 the scavenging control, and is a predetermined value.

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

[0042] After executing the process of 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. Then, when the intake pressure PIM acquired in the process of S160 has decreased by a predetermined value or more with respect to the intake pressure PIM acquired in the process of S140, the control device 100 determines that the intake pressure PIM has decreased.

[0043] And until it is determined in the process of S160 that the intake pressure PIM has decreased, the control device 100 repeatedly executes the processes of S150 and S160. 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 a negative determination is made in the process of S140 above, or if the process of S170 above has ended, the control device 100 executes the process of S180. In the process of S180, the control device 100 determines whether or not the driving time T of the supercharger 24 is equal to or greater than a predetermined determination value Tref. The driving time T is the elapsed time since the drive of the supercharger 24 was started in the process of S130 above, and is measured by the control device 100. The determination value Tref is the minimum driving time of the supercharger 24 required for scavenging in the crankcase 19, and is a predetermined value.

[0045] And until it is determined in the process of S180 that the driving time T is equal to or greater than the determination value Tref, the control device 100 repeatedly executes the process of S180. If it is determined in the process of S180 that the driving time T is equal to or greater than 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. Then, the control device 100 ends this process.

[0046] <Operations and Effects of this Embodiment> (1) When the engine is stopped, scavenging control is executed to drive the motor 24M of the supercharger 24 with the flow rate adjustment valve 40 closed. By driving the motor 24M of the supercharger 24, fresh air flows into the crankcase 19 through the first passage. The fresh air that has flowed into the crankcase 19 flows into the intake passage through the second passage together with the blow-by gas in the crankcase 19, so that the crankcase 19 is scavenged. Therefore, even when the internal combustion engine 10 is stopped, the crankcase 19 can be scavenged.

[0047] (2) When the intake valve 81 and the exhaust valve 82 are both open during scavenging control, that is, when valve overlap occurs, the blow-by gas that has flowed into the intake passage flows out to the exhaust passage 90 of the internal combustion engine 10. Therefore, 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 to the exhaust passage 90, so that the intake pressure at a position downstream of the flow rate adjustment valve 40 increases. Therefore, in the present embodiment, when the intake pressure PIM detected during the execution of scavenging control is equal to or higher than the determination value PIMref and it can be determined that valve overlap does not occur, the control device 100 executes motor ring 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 to cause valve overlap. Therefore, scavenging in the crankcase 19 can be performed more suitably.

[0048] (3) When the temperature of the internal combustion engine 10 when the engine is stopped is equal to or lower than a predetermined threshold value and it is determined that the internal combustion engine 10 is in a low-temperature environment (S110: YES in FIG. 2), the control device 100 executes scavenging control. Therefore, when the temperature of the internal combustion engine 10 when the engine is stopped exceeds the predetermined threshold value and it is difficult for condensed water to be generated in the crankcase 19, scavenging control is not executed. Therefore, unnecessary power consumption caused by driving the motor 24M of the supercharger 24 can be suppressed.

[0049] <Modification Example> Note that this embodiment can be implemented with the following modifications. This embodiment and the following modification examples can be implemented in combination with each other within a technically non - conflicting range.

[0050] · If scavenging control is executed immediately when the engine stops, there is a possibility that the motor driving sound of the supercharger 24 may be heard by the vehicle occupants even though the engine has stopped, which may give the occupants a sense of discomfort. Therefore, scavenging control may be executed after a predetermined time has elapsed since the engine stopped. In this case, scavenging control is executed when there is a high possibility that the vehicle occupants have gotten out of the vehicle and left. Therefore, it is possible to suppress giving the vehicle occupants the sense of discomfort as described above.

[0051] FIG. 3 shows a part of the processing procedure executed by the control device 100 to realize 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 FIG. 3, before performing the process of S110 shown in FIG. 2, the control device 100 executes the process of S200. In the process of S200, the control device 100 determines whether or not a predetermined time has elapsed since the engine stopped. As the predetermined time, for example, the time required for the vehicle occupants to leave the vehicle to a certain extent after the engine stops can be set. And the control device 100 repeatedly executes the process of S200 until it is determined that a predetermined time has elapsed since the engine stopped.

[0053] In the process of S200, when it is determined that a predetermined time has elapsed since the engine stopped (S200: YES), the control device 100 executes the processes after S110 described above. · The scavenging control described above may be executed multiple times with an intervening default pause period. In this case, scavenging in the crankcase 19 is mainly performed by the scavenging control executed for the first time. Then, in the scavenging control executed after the first time, by introducing fresh air into the crankcase 19, it is possible to dry the condensed water adhering to the bore of the cylinder, the inner wall of the crankcase 19, etc. Note that the number of executions of the scavenging control can be set as appropriate.

[0054] FIG. 4 shows a part of the processing procedure executed by the control device 100 to implement this modification example. As shown in the figure, after executing the processing of S190 shown in FIG. 2, the control device 100 executes each of the processes of S300 to S340.

[0055] In the process of S300, the control device 100 determines whether or not the stop time TS of the supercharger 24 is equal to or greater than a predetermined determination value TSref. The stop time TS is the elapsed time since the drive of the supercharger 24 was stopped in the process of S190 above, and is measured by the control device 100. The determination value TSref is a beneficial drive stop time of the supercharger 24 for drying the inside of the crankcase 19, and is a predetermined default value.

[0056] And until it is determined in the process of S300 that the stop time TS is equal to or greater than the determination value TSref, the control device 100 repeatedly executes the process of S300. If it is determined in the process of S300 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 or not the drive time T of the supercharger 24 is equal to or greater than a predetermined determination value Tref (S320). The drive time T is the elapsed time since the drive of the supercharger 24 was started in the process of S310 above, and is measured by the control device 100. The determination value Tref is a beneficial drive time of the supercharger 24 for drying the inside of the crankcase 19, and is a predetermined default value.

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

[0059] ·In the above embodiment, it was determined whether to execute the motor ring control based on the intake pressure PIM. In addition, the determination of whether to execute the motor ring control based on the intake pressure PIM may be omitted. And the motor ring control may be performed from the start to the end of the driving of the supercharger 24.

[0060] ·Although the suction passage 32 was connected to the surge tank 60, the connection site may be appropriately changed as long as it is a site downstream of the flow rate adjustment valve 40 in the intake passage. ·The internal combustion engine 10 may be provided with only one of the port injection valve 83 or the in-cylinder injection valve 84.

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

[0062] ·The internal combustion engine 10 may be provided with an EGR device that recirculates the exhaust gas to the intake passage. G ·Gaseous fuels such as LPG and CNG may be used as the engine fuel of the internal combustion engine 10. ·Liquid fuels such as gasoline, light oil, or alcohol fuel may be used as the engine fuel of the internal combustion engine 10.

[0063] ·The hybrid system of the vehicle is not limited to that shown in FIG. 1, and other hybrid systems may also be used. ·The number of motor generators provided in the vehicle can be appropriately changed.

[0064] ·A vehicle having only the internal combustion engine 10 as a prime mover may also be used. In the case of this modification example, for example, the above motor ring control can be implemented by driving a starter motor that rotates the crankshaft 18 when starting the engine.

[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 (such as an ASIC or the like) that processes at least a part of the software processing executed in the above embodiment. That is, the control device 100 may have any of the following configurations (a) to (c). (a) It includes a processing device 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) It includes a processing device and a program storage device that execute a part of the above processing according to a program, and a dedicated hardware circuit that executes the remaining processing. (c) It includes a dedicated hardware circuit that executes all of the above processing. Here, there may be a plurality of software circuits including a processing device and a program storage device, and dedicated hardware circuits. That is, the above processing may be executed by a processing circuit including at least one of one or more software circuits and one or more dedicated hardware circuits. The program storage device, that is, the computer-readable medium, includes any available medium that can be accessed by a general-purpose or dedicated computer.

Description of Reference Numerals

[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 introduction passage, 38…Separator, 40…Flow control valve, 51…Crank angle sensor, 52…Accelerator 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, wherein the internal combustion engine includes an intake passage, a supercharger that drives a compressor wheel provided in the intake passage by a motor, a flow rate adjustment valve provided downstream of the compressor wheel in the intake passage, a first passage that communicates the intake passage between the compressor wheel and the flow rate adjustment valve with a crankcase, and a second passage that communicates the intake passage downstream of the flow rate adjustment valve with the crankcase, and the control device includes a processing circuit configured to execute scavenging control for driving the motor with the flow rate adjustment valve closed when engine stop is performed. A control device for an internal combustion engine.

2. The internal combustion engine is configured such that valve overlap, in which a part of the valve opening period of an intake valve that opens and closes an intake port of the internal combustion engine overlaps with a part of the valve opening period of an exhaust valve that opens and closes an exhaust port of the internal combustion engine, is formed at engine stop, and has an intake pressure sensor configured to detect the intake pressure at a site downstream of the flow rate adjustment valve in the intake passage, and the processing circuit is configured to execute motoring control for rotating a crankshaft of the internal combustion engine when the intake pressure detected during execution of the scavenging control is equal to or higher than a predetermined determination value. The control device for an internal combustion engine according to Claim 1.

3. The processing circuit is configured to execute the scavenging control when the temperature of the internal combustion engine when engine stop is performed is equal to or lower than a predetermined threshold value. The control device for an internal combustion engine according to Claim 1.

4. The processing circuit is configured to execute the scavenging control after a predetermined time has elapsed since engine stop was performed. The control device for an internal combustion engine according to Claim 1.

5. The processing circuit is configured to execute the scavenging control a plurality of times with a predetermined rest period interposed therebetween. The control device for an internal combustion engine according to Claim 1.

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