Control device for internal combustion engine

Abstract

The invention provides a control device for an internal combustion engine. The control device is configured to control the internal combustion engine. An internal combustion engine includes an intake passage, an electric motor, a supercharger, a flow rate adjustment valve, a crankcase, and first and second passages connected to the crankcase. The supercharger uses a motor to drive a compressor impeller provided in an intake passage. The flow rate adjustment valve is provided downstream of the compressor impeller in the intake passage. The control device is provided with a processing circuit configured so as to execute scavenging control for driving the motor in a state where the flow rate adjustment valve is closed when the internal combustion engine is stopped.

Description

Technical Field

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

[0002] For example, an internal combustion engine described in Japanese Unexamined Patent Application Publication No. 2014-92070 includes: a flow rate adjustment valve provided in an intake passage; a first passage that fluidly connects the intake passage upstream of the flow rate adjustment valve to a crankcase; and a second passage that fluidly connects the intake passage downstream of the flow rate adjustment valve to the crankcase. Further, by using the pressure in the intake passage generated during the operation of the internal combustion engine, blow-by gas in the crankcase is introduced into the intake passage and scavenging is performed.

[0003] However, if the internal combustion engine is repeatedly stopped and started before the warm-up of the internal combustion engine is completed, the temperature in the crankcase does not rise. Therefore, it is easy to generate condensed water in the crankcase due to moisture contained in the blow-by gas. When condensed water is generated in the crankcase, for example, the condensed water may mix and accumulate in the lubricating oil stored in the oil pan. Therefore, it is preferable to scavenge the crankcase even during the stop of the internal combustion engine. However, in the conventional structure that uses the pressure in the intake passage generated during the operation of the internal combustion engine, it is difficult to scavenge the crankcase during the stop of the internal combustion engine. Summary of the Invention

[0004] One aspect of the present disclosure provides a control device configured to control an internal combustion engine. The internal combustion engine includes: an intake passage; a compressor impeller provided in the intake passage; an electric motor; a supercharger that drives the compressor impeller by the electric motor; a flow rate adjustment valve provided in the intake passage downstream of the compressor impeller; a crankcase; a first passage that fluidly connects the intake passage between the compressor impeller and the flow rate adjustment valve to the crankcase; and a second passage that fluidly connects the intake passage downstream of the flow rate adjustment valve to the crankcase. The control device includes a processing circuit configured to perform scavenging control of driving the electric motor with the flow rate adjustment valve closed when the internal combustion engine is stopped. Brief Description of the Drawings

[0005] Figure 1 It is a schematic diagram showing the structure of an internal combustion engine and a drive system according to an embodiment.

[0006] Figure 2 It is a flowchart showing the order of processing performed by the control device according to the embodiment.

[0007] Figure 3 It is a flowchart showing the steps of processing performed by the control device in a modification of the embodiment.

[0008] Figure 4 It is a flowchart showing the steps of the processing executed by the control device in a modification example of this embodiment. Detailed Embodiment

[0009] Hereinafter, an embodiment in which a control device for an internal combustion engine mounted on a vehicle is embodied will be described.

[0010] <Structure of Internal Combustion Engine and Drive System>

[0011] As Figure 1 shown, the internal combustion engine 10 includes: a cylinder block 11, a cylinder head 12, a valve cover 13, and an oil pan 14. A cylinder 16 in which a piston 15 is disposed so as to be able to reciprocate is provided in the cylinder block 11.

[0012] 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 are provided in the cylinder head 12.

[0013] An intake valve 81 for opening and closing the intake port 30 is provided in 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. An intake-side variable valve timing mechanism 85 is provided in the drive system of the intake valve 81, and the intake-side variable valve timing mechanism 85 is a variable valve mechanism that changes the valve timing (opening and closing timing) of the intake valve 81.

[0014] An exhaust valve 82 for opening and closing the exhaust port 70 is provided in the exhaust port 70. The exhaust valve 82 opens and closes in synchronization with the rotation of the crankshaft 18. An exhaust-side variable valve timing mechanism 86 is provided in the drive system of the exhaust valve 82, and the exhaust-side variable valve timing mechanism 86 is a variable valve mechanism that changes the valve timing (opening and closing timing) of the exhaust valve 82.

[0015] An intake port injection valve 83 for injecting hydrogen as the fuel of the internal combustion engine into the intake port 30, an in-cylinder injection valve 84 for directly injecting hydrogen as the fuel of the internal combustion engine into the combustion chamber 17, and a spark plug (not shown) are provided in the cylinder head 12.

[0016] A crankcase 19 is provided at the lower part of the cylinder block 11, and the crankcase 19 houses the crankshaft 18 which is the output shaft of the internal combustion engine 10. An oil pan 14 for storing lubricating oil is provided at the lower part of the crankcase 19.

[0017] 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.

[0018] In the intake pipe 20, an air cleaner 21, a compressor impeller 24C of a supercharger 24, an intercooler 27, a throttle valve 28, and a flow rate adjustment valve 40 are provided in sequence from its upstream side.

[0019] The air cleaner 21 filters the intake air entering the intake pipe 20.

[0020] The supercharger 24 is a device that supercharges the air in the intake pipe 20, and the compressor impeller 24C is rotationally driven by an electric motor 24M.

[0021] The intercooler 27 cools the air that has passed through the compressor impeller 24C.

[0022] The throttle valve 28 is a valve that adjusts the intake air amount of the internal combustion engine 10, and changes the valve opening degree by rotating a butterfly valve using an electric motor.

[0023] 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 changes the valve opening degree by an electric motor. The flow rate adjustment valve 40 in the present embodiment has the same valve structure as the throttle valve 28, but may also have a different valve structure.

[0024] An exhaust passage 90 is connected to the downstream of the exhaust port 70.

[0025] A blow-by gas treatment device is provided in the internal combustion engine 10, and the blow-by gas treatment device treats the gas, so-called blow-by gas, that leaks from the combustion chamber 17 into the crankcase 19 during the compression stroke and / or the combustion stroke.

[0026] The blow-by gas treatment device includes a fresh air introduction passage 37 for introducing fresh air into the crankcase 19 for scavenging. One end of the two 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 penetrates through the cover 13 and passes through the inside of the cylinder head 12 and the cylinder block 11, and is connected to the crankcase 19. An oil separator, i.e., a separator 38, provided in the cover 13 is provided in the middle of the fresh air introduction passage 37. The fresh air introduction passage 37 and the separator 38 constitute a first passage that fluidly connects the intake passage between the compressor impeller 24C and the flow rate adjustment valve 40 and the crankcase 19.

[0027] The blow-by gas treatment device includes a suction passage 32 for guiding the blow-by gas in the crankcase 19 to an oil separator, i.e., a separator 31, provided in the cylinder head cover 13. The end of the suction passage 32 connected to the separator 31 opens inside the crankcase 19. In addition, a separator 31 may be provided in the middle of the suction passage 32.

[0028] The separator 31 is connected to the surge tank 60 via the PCV passage 35. These suction passages 32, the separator 31, and the PCV passage 35 constitute a second passage that fluidly connects the intake passage downstream of the specific flow rate adjustment valve 40 to the crankcase 19.

[0029] Fresh air is introduced into the crankcase 19 via the fresh air introduction passage 37. Further, if the opening degree of the flow rate adjustment valve 40 is adjusted to be smaller, the pressure on the downstream side of the specific flow rate adjustment valve 40 in the intake pipe 20 decreases. If the pressure on the downstream side of the specific 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 passage 32. The blow-by gas sucked into the intake pipe 20 is transported to the combustion chamber 17 together with the intake air and burned.

[0030] The crankshaft 18 is mechanically connected to the carrier C of the planetary gear mechanism 300 that constitutes the power distribution 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 is mechanically connected to the drive wheel 400 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 through the inverter 330. Further, an alternating voltage is applied to the terminals of the second motor generator 320 through the inverter 340. Thus, the vehicle of the present embodiment becomes a vehicle equipped with a hybrid system having the internal combustion engine 10 and the motor generator as prime movers.

[0031] The control device 100 targets the internal combustion engine 10 for control. And, the control device 100 operates various operation target devices such as the throttle valve 28, the flow rate adjustment valve 40, the intake port injection valve 83 and the in-cylinder injection valve 84, the spark 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. Further, the controller 100 operates the inverter 330 to control the first motor generator 310. Further, the controller 100 operates the inverter 340 to control the second motor generator 320.

[0032] The control device 100 includes circuits such as a CPU 110 that performs arithmetic processing and a memory 120 that stores control programs or data. And, the control device 100 executes processes related to various controls by the CPU 110 executing the programs stored in the memory 120. Further, although not shown, the control device 100 is composed of a plurality of control units including a control unit for the internal combustion engine, a control unit for the first motor generator 310, and a control unit for the second motor generator 320.

[0033] Detection signals from various sensors are input to the control device 100. For example, the detection signal of an air flow meter 22 that detects the intake air amount GA, and the detection signal of a throttle sensor 25 that detects the opening degree of a throttle valve 28, i.e., the throttle opening degree TA, are input to the control device 100. In addition, the detection signal of a valve opening degree sensor 26 that detects the opening degree of a flow control valve 40, i.e., the valve opening degree BA, is input to the control device 100. In addition, in order to calculate the internal combustion engine speed NE, the detection signal of a crank angle sensor 51 that detects the rotation angle (crank angle) of a crankshaft 18 is input to the control device 100. In addition, the detection signal of an accelerator operation amount sensor 52 that detects the operation amount of an accelerator pedal, i.e., the accelerator operation amount ACP, is input to the control device 100. In addition, the detection signals of a water temperature sensor 53 that detects the temperature of the cooling water of the internal combustion engine 10, i.e., the cooling water temperature THW, and an oil temperature sensor 54 that detects the temperature of the lubricating oil of the internal combustion engine 10, i.e., the oil temperature THO, are input to the control device 100. In addition, the detection signal of a vehicle speed sensor 55 that detects the vehicle speed SP of a vehicle on which the internal combustion engine 10 is mounted is input to the control device 100. In addition, the detection signal of an intake air pressure sensor 56 that detects the pressure in a surge tank 60, i.e., the intake air pressure PIM, is input to the control device 100. In addition, the output signal Sm1 of a first rotation angle sensor 350 that detects the rotation angle of a first motor generator 310 is input to the control device 100. In addition, the output signal Sm2 of a second rotation angle sensor 360 that detects the rotation angle of a second motor generator 320 is input to the control device 100.

[0034] The control device 100 calculates an internal combustion engine load rate KL based on the internal combustion engine speed NE and the intake air amount GA. The internal combustion engine load rate KL is a parameter that determines the amount of air filled into a combustion chamber 17, and is the ratio of the intake air amount per combustion cycle of one cylinder to a reference intake air amount. The reference intake air amount is variably set according to the internal combustion engine speed NE.

[0035] The control device 100 calculates a required torque for vehicle running based on the accelerator operation amount ACP and the vehicle speed SP. And 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 to satisfy the required torque of the vehicle. For example, when the required output Pe of the internal combustion engine 10 is "0", EV running is performed in which the operation of the internal combustion engine 10 is stopped and running is performed using the output torque of the second motor generator 320.

[0036] Hydrogen, which is used as fuel for the internal combustion engine, has a wider range of combustible mixtures compared to gasoline, and can burn even with a lean mixture. Therefore, the control device 100 performs output control of the internal combustion engine 10 as follows.

[0037] That is, when the required output Pe is large, the control device 100 executes control to reduce the air-fuel ratio of the air-fuel mixture compared to 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 predetermined value, for example, an opening degree near full opening. And the required injection amount Qd is set such that the larger the required output Pe, the larger the required injection amount Qd. The required injection amount Qd is the target value of the fuel injected from the intake port injection valve 83 and the in-cylinder injection valve 84. And the control device 100 controls the intake port injection valve 83 and the in-cylinder injection valve 84 to obtain the required injection amount Qd. Thus, in the internal combustion engine 10, the output is adjusted by changing the air-fuel ratio of the air-fuel mixture through adjustment of the fuel injection amount.

[0038] In addition, the control device 100 calculates the target valve timing of the intake valve 81 and / or the exhaust valve 82 based on parameters indicating the operating state of the internal combustion engine, such as the internal combustion engine speed NE and the internal combustion engine load factor KL. And the control device 100 controls the intake-side variable valve timing mechanism 85 and / or the exhaust-side variable valve timing mechanism 86 based on parameters related to control such as the target valve timing.

[0039] In addition, when the internal combustion engine stops, the control device 100 calculates the target valve timing of the intake valve 81 and / or the exhaust valve 82 in such a way that a part of the valve opening period of the intake valve 81 overlaps with a part of the valve opening period of the exhaust valve 82 to form valve overlap. And the control device 100 controls the intake-side variable valve timing mechanism 85 and / or the exhaust-side variable valve timing mechanism 86 to form valve overlap when the internal combustion engine stops.

[0040] In addition, the control device 100 calculates the target boost pressure PTCp based on parameters indicating the operating state of the internal combustion engine, such as the internal combustion engine speed NE and the internal combustion engine load factor KL. And the drive of the motor 24M is controlled based on parameters related to control such as the target boost pressure PTCp, thereby performing boost pressure control of the supercharger 24.

[0041] <Scavenging control>

[0042] The internal combustion engine fuel of the internal combustion engine 10 is hydrogen as a gaseous fuel. Therefore, compared with liquid fuels such as gasoline, the proportion of hydrogen molecules in the fuel is large. Therefore, the amount of moisture contained in the blowby is more than that of liquid fuels. Here, if the internal combustion engine 10 is repeatedly stopped and started before the preheating of the internal combustion engine 10 is completed, the temperature in the crankcase 19 will not rise. Therefore, it is easy to generate condensed water in the crankcase 19 due to the moisture contained in the blowby. When condensed water is generated in the crankcase 19, for example, the condensed water may mix into and accumulate in the lubricating oil stored in the oil pan 14.

[0043] Therefore, the control device 100 executesFigure 2 The processing shown is such that scavenging of the crankcase 19 can be performed not only during the operation of the internal combustion engine 10 but also during the period of stoppage of operation.

[0044] Figure 2 Indicates the sequence of the processing executed by the control device 100. Figure 2 The processing shown is implemented by the CPU 110 executing a program stored in the memory 120 of the control device 100. Additionally, Figure 2 The processing shown starts when the control device 100 determines that the operation of the internal combustion engine 10 has stopped. Additionally, hereinafter, the step numbers of the respective processes are represented by numbers preceded by "S".

[0045] In Figure 2 In the series of processing shown, 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 stoppage of the internal combustion engine is below a predetermined threshold value, the control device 100 determines that the internal combustion engine 10 is in a low-temperature environment. As a value representing the temperature of the internal combustion engine 10, for example, the coolant water temperature THW and the oil temperature THO can be adopted. Additionally, the temperature of the internal combustion engine 10 can also be estimated based on parameters such as the operating time of the internal combustion engine 10 before stoppage of operation.

[0046] When it is determined in the process of S110 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 to be in the fully open state and adjusts the opening of the flow rate adjustment valve 40 to be in the fully closed state.

[0047] Next, the control device 100 drives the supercharger 24 by rotating the electric motor 24M (S130). By executing the processes of S120 and S130, when the internal combustion engine 10 is stopped, scavenging control of the electric motor 24M that drives the supercharger 24 with the flow rate adjustment valve 40 closed is performed.

[0048] 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 above-described valve overlap does not occur during the execution of the scavenging control and is a predetermined value.

[0049] When it is determined in the process of S140 that the intake pressure PIM is equal to or higher than the determination value PIMref (S140: Yes), the control device 100 starts motor drive control for rotating the crankshaft 18 by driving the first motor generator 310 (S150).

[0050] After the process of S150 is executed, the control device 100 determines whether the intake pressure PIM has decreased (S160). In the process of S160, the control device 100 obtains the intake pressure PIM. And, when the intake pressure PIM obtained in the process of S160 has decreased by a predetermined value or more with respect to the intake pressure PIM obtained in the process of S140, the control device 100 determines that the intake pressure PIM has decreased.

[0051] And, the control device 100 repeatedly executes the process of S150 and the process of S160 until it is determined in the process of S160 that the intake pressure PIM has decreased.

[0052] When it is determined in the process of S160 that the intake pressure PIM has decreased (S160: YES), the control device 100 stops the rotation of the crankshaft 18 by stopping the drive of the first motor generator 310, and ends the motor drive control (S170).

[0053] When a negative determination is made in the above-mentioned process of S140, or when the above-mentioned process of S170 is ended, the control device 100 executes the process of S180.

[0054] In the process of S180, the control device 100 determines whether the drive time T of the supercharger 24 is equal to or greater than a predetermined determination value Tref. The drive time T is the elapsed time since the drive of the supercharger 24 started in the above-mentioned process of S130, and is measured by the control device 100. The determination value Tref is the minimum drive time of the supercharger 24 required for scavenging in the crankcase 19, and is a predetermined value determined in advance.

[0055] And, the control device 100 repeatedly executes the process of S180 until it is determined in the process of S180 that the drive time T is equal to or greater than the determination value Tref.

[0056] When it is determined in the process of S180 that the drive 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. And, the control device 100 ends this process.

[0057] <Functions and Effects of this Embodiment>

[0058] (1)When the internal combustion engine stops, scavenging control of the motor 24M that drives the supercharger 24 is performed 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 and the blow-by gas in the crankcase 19 flow into the intake passage through the second passage, so the crankcase 19 is scavenged. Therefore, even during the period when the internal combustion engine 10 is stopped, the crankcase 19 can be scavenged.

[0059] (2)During the period when scavenging control is implemented, when both the intake valve 81 and the exhaust valve 82 are open, 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 of the crankcase 19 is promoted. 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 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 drive control to rotate the crankshaft 18 of the internal combustion engine 10. When the crankshaft 18 rotates, the intake valve 81 and / or the exhaust valve 82 are driven to cause valve overlap. Therefore, scavenging of the crankcase 19 can be performed more appropriately.

[0060] (3)When the temperature of the internal combustion engine 10 when the internal combustion engine stops is below a predetermined threshold value and it is determined that the internal combustion engine 10 is in a low-temperature environment ( Figure 2 in S110: Yes), the control device 100 executes scavenging control. Therefore, when the temperature of the internal combustion engine 10 when the internal combustion engine stops exceeds the predetermined threshold value and it is not easy to generate condensed water in the crankcase 19, scavenging control is not executed. Therefore, unnecessary power consumption generated by driving the motor 24M of the supercharger 24 can be suppressed.

[0061] <Modification Example>

[0062] In addition, the present embodiment can be modified and implemented as follows. The present embodiment and the following modification examples can be implemented in combination with each other within a range where there is no technical contradiction.

[0063] ·The scavenging control can be executed immediately at the time when the internal combustion engine 10 stops, or can be executed after the internal combustion engine 10 stops. If the scavenging control is executed immediately at the time when the internal combustion engine 10 stops, there is a possibility that the vehicle occupants may hear operating sounds such as the motor driving sound of the supercharger 24 although the internal combustion engine is stopped. Therefore, it is possible to cause discomfort to the occupants due to the motor driving sound. Therefore, the scavenging control can also be executed after a predetermined time has elapsed since the internal combustion engine stopped. In this case, the scavenging control is executed when the possibility that the vehicle occupants get out of the vehicle and leave is high. Therefore, it is possible to suppress causing the above-mentioned discomfort to the vehicle occupants.

[0064] Figure 3 A part of the processing steps executed by the control device 100 to implement this modification example is shown. The processing shown in this figure also starts when the control device 100 determines that the operation of the internal combustion engine 10 has stopped.

[0065] As Figure 3 shown, before performing the processing of S110 shown in Figure 2 , the control device 100 executes the processing of S200.

[0066] In the processing of S200, the control device 100 determines whether a predetermined time has elapsed since the internal combustion engine stopped. As the predetermined time, for example, parameters such as the time required for the vehicle occupants to leave the vehicle to a certain extent since the internal combustion engine stop can be set. And the control device 100 repeatedly executes the processing of S200 until it is determined that a predetermined time has elapsed since the internal combustion engine stopped.

[0067] When it is determined in the processing of S200 that a predetermined time has elapsed since the internal combustion engine stopped (S200: Yes), the control device 100 executes the processing after the above-mentioned S110.

[0068] ·The above-mentioned scavenging control can also be executed multiple times at intervals of a predetermined rest period. In this case, through the scavenging control executed for the first time, scavenging in the crankcase 19 is mainly performed. And in the scavenging control executed after the first time, by introducing fresh air into the crankcase 19, for example, it is possible to dry the condensed water adhering to the cylinder bore of the cylinder and the inner wall of the crankcase 19. In addition, the number of executions of the scavenging control can be set appropriately.

[0069] Figure 4 A part of the processing steps executed by the control device 100 to implement this modification example is shown. As shown in this figure, after executing the processing of S190 shown in Figure 2 , the control device 100 executes each processing of S300 to S340.

[0070] In the process of S300, the control device 100 determines whether 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 the drive stop time of the supercharger 24 that is beneficial for drying the inside of the crankcase 19, and is a predetermined fixed value.

[0071] Moreover, the control device 100 repeatedly executes the process of S300 until it is determined in the process of S300 that the stop time TS is equal to or greater than the determination value TSref.

[0072] When 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 electric motor 24M (S310).

[0073] Next, the control device 100 determines whether 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 the drive time of the supercharger 24 that is beneficial for drying the inside of the crankcase 19, and is a predetermined fixed value.

[0074] Moreover, the control device 100 repeatedly executes the process of S310 and the process of S320 until it is determined in the process of S320 that the drive time T is equal to or greater than the determination value Tref.

[0075] When it is determined in the process of S320 that the drive time T is equal to or greater than the determination value Tref (S320: Yes), the control device 100 stops the supercharger 24 by stopping the rotation of the electric motor 24M (S340). And the control device 100 ends this process.

[0076] · In the above embodiment, the motor drive control is determined based on the intake pressure PIM. In addition, the determination of whether to execute the motor drive control based on the intake pressure PIM is omitted. Moreover, the motor drive control can also be performed from the start to the end of the drive of the supercharger 24.

[0077] · The suction passage 32 is connected to the surge tank 60, but it may be a part downstream of the flow rate adjustment valve 40 in the intake passage, and the connection part can also be changed appropriately.

[0078] · The internal combustion engine 10 may also be provided with only either the intake port injection valve 83 or the in-cylinder injection valve 84.

[0079] · The internal combustion engine 10 may also be equipped with either the intake-side variable valve timing mechanism 85 or the exhaust-side variable valve timing mechanism 86.

[0080] · A PCV valve may also be provided in the PCV passage 35, and this PCV valve opens when the pressure in the surge tank 60 is lower than the pressure in the separator 31, allowing blow-by gas to flow from the separator 31 into the surge tank 60.

[0081] · The internal combustion engine 10 may also be equipped with an EGR device that returns exhaust gas to the intake passage.

[0082] · As the fuel for the internal combustion engine 10, gaseous fuels such as LPG and CNG may also be used.

[0083] · As the fuel for the internal combustion engine 10, liquid fuels such as gasoline, light oil, or alcohol fuel may also be used.

[0084] · The hybrid system of the vehicle is not limited to Figure 1 the system shown, and other hybrid systems may also be used.

[0085] · The number of electric generators provided in the vehicle can be appropriately changed.

[0086] · It may also be a vehicle equipped only with the internal combustion engine 10 as the prime mover. In the case of this modification example, for example, the above-described motor drive control can be implemented by driving a starting motor that rotates the crankshaft 18 when the internal combustion engine is started.

[0087] The above 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 also include, for example, a dedicated hardware circuit (such as an ASIC, etc.) that processes at least a part of the software processing performed in the above-described embodiment. That is, the control device 100 may have any of the following structures (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 ROM that stores the program. (b) It includes a processing device that executes a part of the above processing according to a program, a program storage device, 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, the software circuit including the processing device and the program storage device and the dedicated hardware circuit may be plural. 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 all available media that can be accessed by a general-purpose or dedicated computer.

Claims

1. A control device for an internal combustion engine, The internal combustion engine comprises: an intake passage; a compressor impeller disposed in the intake passage; an electric motor; a supercharger, the compressor impeller being driven by the electric motor; a flow regulating valve disposed in the intake passage at a position downstream of the compressor impeller; a crankcase; a first passage for fluidly connecting the intake passage and the crankcase between the compressor impeller and the flow regulating valve; and a second passage for fluidly connecting the intake passage and the crankcase at a position downstream of the flow regulating valve. The control device includes a processing circuit configured to execute scavenging control for driving the electric motor in a state where the flow rate regulating valve is closed when the internal combustion engine is stopped.

2. The control device for an internal combustion engine according to claim 1, wherein: The internal combustion engine also has: a crankshaft; an air intake; an exhaust port; an intake valve that selectively opens and closes the intake port; an exhaust valve that selectively opens and closes the exhaust port; and an intake pressure sensor configured to detect an intake pressure at a portion of the intake passage downstream of the flow regulating valve, The internal combustion engine is configured such that, when the internal combustion engine is stopped, a valve overlap is formed in which a portion of the opening period of the intake valve overlaps a portion of the opening period of the exhaust valve. The processing circuit is configured to execute motor drive control for rotating the crankshaft of the internal combustion engine by the electric motor when the intake pressure detected during execution of the scavenging control is equal to or greater than a predetermined determination value.

3. The control device for an internal combustion engine according to claim 1, wherein: The processing circuit is configured to execute the scavenging control when a temperature of the internal combustion engine when the internal combustion engine is stopped is equal to or lower than a predetermined threshold value.

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

5. The control device for an internal combustion engine according to claim 1, wherein: The processing circuit is configured to execute the scavenging control a plurality of times at intervals of a predetermined rest period.

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