Control device for internal combustion engine

Abstract

To reduce hydrogen concentration in a crankcase without providing a ventilation fan.SOLUTION: An internal combustion engine 10 uses hydrogen as fuel. The internal combustion engine 10 has a communication passage causing a crankcase 19 and a surge tank 60 to communicate with each other. The control device 100 executes control for making an air fuel ratio of a mixture smaller when a target output of the internal combustion engine 10 is large than when the target output is small. The control device 100 executes pressure reduction processing for reducing pressure in the surge tank 60 when the target output is less than a prescribed value. The pressure reduction processing is the processing for reducing the pressure in the surge tank 60 as compared with the pressure before execution of the pressure reduction processing.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Internal combustion engines that use hydrogen as fuel are known. In such internal combustion engines, hydrogen gas accumulates in the crankcase. Therefore, it is desirable to keep the hydrogen concentration in the crankcase below the lower limit of the flammable range. Thus, for example, in the internal combustion engine described in Patent Document 1, a ventilation fan is provided to discharge hydrogen gas from the inside of the crankcase to the outside.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, providing a ventilation fan requires, for example, space for mounting the ventilation fan. In addition, for example, the space constraints when mounting an internal combustion engine equipped with a ventilation fan increase. Therefore, it is desired to reduce the hydrogen concentration in the crankcase without providing such a ventilation fan.

Means for Solving the Problems

[0005] The control device for an internal combustion engine that solves the above problems is applied to an internal combustion engine that uses hydrogen as fuel. The internal combustion engine has a communication passage that communicates the crankcase and the intake passage. The control device executes control to make the air-fuel ratio of the air-fuel mixture smaller when the target output of the internal combustion engine is large than when it is small. When the target output is less than a predetermined value, this control device executes a pressure reduction process for reducing the pressure in the intake passage, and the pressure reduction process is a process for reducing the pressure in the intake passage compared to before the execution of the pressure reduction process.

[0006] According to the same configuration, when the target output is less than a predetermined value, the pressure reduction process is executed, so that the pressure in the intake passage decreases. When the pressure in the intake passage decreases, the hydrogen gas accumulated in the crankcase is discharged into the intake passage through the communication passage, so that the hydrogen concentration in the crankcase decreases. Therefore, the hydrogen concentration in the crankcase can be reduced without providing a ventilation fan.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Modes 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 the Internal Combustion Engine> As shown in FIG. 1, an internal combustion engine 10 mounted on a vehicle 500 includes a cylinder block 11, a cylinder head 12, a head cover 13, and an oil pan 14. Inside the cylinder block 11, a cylinder 16 in which a piston 15 is reciprocally arranged is provided.

[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 from the combustion chamber 17. An intake valve 81 is provided in the intake port 30. In the drive system of this 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. An exhaust valve 82 is provided in the exhaust port 70. In the drive system of this 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.

[0010] Also, the cylinder head 12 is provided with a port injection valve 83 for injecting hydrogen as fuel into the intake port 30, a direct injection valve 84 for directly injecting hydrogen as fuel into the combustion chamber 17, and a spark plug (not shown).

[0011] 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.

[0012] 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.

[0013] In the intake pipe 20, in order from its upstream side, an air cleaner 21, an air flow meter 22, a compressor wheel 24C of a supercharger 24 driven by using the exhaust gas discharged from the combustion chamber 17, an intercooler 27, a supercharging pressure sensor 25, and a throttle valve 28 are installed. Further, an intake pressure sensor 54 is installed in the surge tank 60. Note that the opening degree of the throttle valve 28 is changed by an electric motor.

[0014] The air cleaner 21 filters the intake air taken into the intake pipe 20. The supercharger 24 supercharges the air in the intake pipe 20. Further, the intercooler 27 cools the air after passing through the compressor wheel 24C. And the throttle valve 28 measures the intake air amount by adjusting the valve opening degree.

[0015] The air flow meter 22 detects the intake air amount GA. Further, the supercharging pressure sensor 25 detects the supercharging pressure PTC which is the pressure of the downstream portion of the compressor wheel 24C in the intake pipe 20. Also, the intake pressure sensor 54 detects the intake pressure PIM which is the pressure in the surge tank 60.

[0016] An exhaust passage 90 is connected to the downstream of the exhaust port 70. In the middle of the exhaust passage 90, a housing for housing the turbine wheel 24T of the supercharger 24 is connected. Also, the upstream portion of the turbine wheel 24T and the downstream portion of the same turbine wheel 24T in the exhaust passage 90 are communicated with each other via a bypass passage 92. In the middle of the bypass passage 92, a wastegate valve (hereinafter referred to as WGV) 93 whose opening degree is adjusted by an actuator is provided. This WGV 93 is a valve that adjusts the amount of exhaust gas flowing through the bypass passage 92. As its opening degree increases, the amount of exhaust gas bypassing the turbine wheel 24T and passing through the bypass passage 92 increases. Therefore, the supercharging pressure of the intake air increased by the supercharger 24 becomes lower.

[0017] 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 the compression stroke or the combustion stroke, so-called blow-by gas. This blow-by gas treatment device includes a suction passage 32 for guiding the blow-by gas in the crankcase 19 to a main separator 31 that is an oil separator provided in the head cover 13. The end of the suction passage 32 connected to the main separator 31 opens into the crankcase 19.

[0018] The main separator 31 is connected to a surge tank 60 via a PCV (positive crankcase ventilation) valve 34 that is a differential pressure valve and a PCV passage 35. The PCV valve 34 opens when the pressure in the surge tank 60 becomes lower than the pressure in the main separator 31, allowing blow-by gas to flow from the main separator 31 into the surge tank 60. These suction passage 32, main separator 31, PCV valve 34, and PCV passage 35 constitute a communication passage that communicates the surge tank 60, which forms part of the intake passage, with the crankcase 19.

[0019] For example, when the supercharging pressure of the supercharger 24 is low, the pressure in the surge tank 60 becomes lower than the pressure in the main separator 31. Therefore, the blow-by gas in the crankcase 19 is sucked into the surge tank 60 through the suction passage 32, main separator 31, PCV valve 34, and PCV passage 35. The sucked blow-by gas is sent to the combustion chamber 17 together with the intake air and burned.

[0020] The main separator 31 is also connected to an ejector 40 via a connection passage 41. The ejector 40 is provided in the middle of a bypass passage 36 that connects the intake pipe 20 upstream of the compressor wheel 24C and the intake pipe 20 downstream of the compressor wheel 24C. The ejector 40 includes a throttle portion for generating a negative pressure by the Venturi effect.

[0021] The supercharger bypass gas treatment device also includes an air introduction passage 37 for introducing intake air into the crankcase 19 for scavenging. One end of the air introduction passage 37 is connected to the intake pipe 20 between the air cleaner 21 and the compressor wheel 24C. The air introduction passage 37 passes through the head cover 13, through the inside of the cylinder head 12 and the cylinder block 11, and is connected to the crankcase 19. An air side separator 38, which is an oil separator installed in the head cover 13, is provided in the middle of the air introduction passage 37.

[0022] When the supercharging pressure of the supercharger 24 is high, air flows from the downstream side to the upstream side in the bypass passage 36, causing a negative pressure in the ejector 40. Then, due to the negative pressure generated in the ejector 40, the blow-by gas in the crankcase 19 is sucked into the inside of the ejector 40 through the suction passage 32, the main separator 31, and the connection passage 41. The blow-by gas sucked into the ejector 40 is introduced into the intake pipe 20 upstream of the compressor wheel 24C through the bypass passage 36 together with the air. The blow-by gas introduced into the intake pipe 20 is sent to the combustion chamber 17 and burned together with the intake air.

[0023] The control device 100 controls the internal combustion engine 10 and operates various operation target devices such as the throttle valve 28, 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 WGV 93.

[0024] The control device 100 includes a central processing unit (hereinafter referred to as CPU) 110, 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.

[0025] The detection signals of the above-described air flow meter 22, supercharging pressure sensor 25, and intake air pressure sensor 54 are input to the control device 100. Further, the detection signal of a crank angle sensor 51 that detects the rotation angle (crank angle) of the crankshaft 18 is also input to the control device 100 in order to calculate the engine rotational speed NE. In addition, detection signals such as a vehicle speed sensor 53 that detects the vehicle speed SP of the vehicle 500 on which the internal combustion engine 10 is mounted and an accelerator operation amount sensor 52 that detects the accelerator operation amount ACP, which is the operation amount of the accelerator pedal, are also input to the control device 100. Note that 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 inflow air amount. Note that the reference inflow air amount is variably set according to the engine rotational speed NE.

[0026] The control device 100 calculates a target output Pe, which is a target value of the output required for the internal combustion engine 10, based on the accelerator operation amount ACP and the vehicle speed SP. When the target output Pe is large, control is executed to make the air-fuel ratio of the air-fuel mixture smaller than when the target 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 open. Then, the required injection amount Qd is set so that the required injection amount Qd increases as the target 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. Then, 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, output adjustment is performed by changing the air-fuel ratio of the air-fuel mixture basically through adjustment of the fuel injection amount instead of the intake air amount.

[0027] In addition, the control device 100 calculates target valve timings of the intake valve 81 and the exhaust valve 82 based on the engine rotational speed NE, the engine load ratio KL, and the like. Then, drive control of the intake-side valve timing variable mechanism 85 and the exhaust-side valve timing variable mechanism 86 is performed based on the target valve timings and the like.

[0028] 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, by adjusting the opening degree of the WGV 93 based on the target supercharging pressure PTCp etc., the supercharging pressure control of the supercharger 24 is performed.

[0029] <Pressure reduction process> As described above, in the internal combustion engine 10, during its operation, the throttle valve 28 is basically maintained at an opening degree near full open. Therefore, the state in which the pressure in the intake passage decreases is limited, and the discharge of blow-by gas from the crankcase 19 to the surge tank 60 through the PCV passage 35 etc. is difficult to progress, and the hydrogen gas contained in the blow-by gas tends to accumulate in the crankcase 19. Also, if hydrogen gas accumulates in the crankcase 19, there is a risk that such hydrogen gas will leak into the atmosphere when the internal combustion engine 10 is being serviced. For example, when checking the amount of lubricating oil stored in the oil pan 14 with an oil level gauge or when removing and inspecting the spark plug, such leakage of hydrogen gas is likely to occur.

[0030] Therefore, in order to reduce the hydrogen concentration in the crankcase 19, the control device 100 executes a pressure reduction process. This pressure reduction process is a process of reducing the pressure in the intake passage when the target output Pe is a small output less than a predetermined value set in advance. Here, when the internal combustion engine 10 is in the idle state or immediately before the vehicle 500 stops, the target output Pe becomes small. Therefore, in the present embodiment, when the internal combustion engine 10 is in the idle state or immediately before the vehicle 500 stops, it is determined that the target output Pe is in a state less than the predetermined value.

[0031] FIG. 2 shows a processing procedure for executing the pressure reduction process. The process shown in FIG. 2 is realized by the CPU 110 repeatedly executing a program stored in the memory 120 at a predetermined cycle. Hereinafter, the step numbers of each process are represented by numbers with "S" attached at the beginning.

[0032] In the series of processes shown in FIG. 2, the CPU 110 first determines whether the current engine operating state is in idle operation (S100). In the process of S100, the CPU 110 acquires, for example, the accelerator operation amount ACP. Then, when the acquired accelerator operation amount ACP is "0", it is determined that the vehicle is in idle operation.

[0033] When it is determined that the engine operating state is in idle operation (S100: YES), the CPU 110 determines whether the vehicle 500 is stopped (S110). In the process of S110, the CPU 110 determines that the vehicle 500 is stopped when, for example, the state where the vehicle speed SP is "0" has elapsed for a predetermined time.

[0034] When it is determined that the vehicle 500 is stopped (S110: YES), the CPU 110 executes a pressure reduction process (S160). As the pressure reduction process, the CPU 110 executes an opening degree change process of reducing the current opening degree of the throttle valve 28 by a specified value α. The specified value α is a value required for the pressure in the surge tank 60 to drop to the pressure required for discharging blow-by gas through the PCV passage 35, and is a predetermined value. The CPU 110 implements this opening degree change process through the opening degree control of the throttle valve 28.

[0035] When a negative determination is made in the process of S100 above, or when a negative determination is made in the process of S110 above, the CPU 110 executes the processes after S120. In the process of S120, the CPU 110 determines whether the current vehicle speed SP is less than the threshold value SPref. The threshold value SPref is a predetermined value, and its magnitude is set so that it can be determined that the vehicle speed SP is low enough to determine that the vehicle 500 is just before stopping based on the fact that the vehicle speed SP is less than the threshold value SPref.

[0036] When it is determined that the vehicle speed SP is less than the threshold value SPref (S120: YES), the CPU 110 determines whether the accelerator operation amount ACP is less than the threshold value ACPref (S130). The threshold value ACPref is a predetermined value, and based on the accelerator operation amount ACP being less than the threshold value ACPref, the magnitude of the value is set so that it can be determined that the accelerator operation amount ACP is small enough to determine that the vehicle 500 is about to stop.

[0037] When it is determined that the accelerator operation amount ACP is less than the threshold value ACPref (S130: YES), the CPU 110 determines whether the accelerator change amount ACPH is less than the threshold value ACPHref (S140). The accelerator change amount ACPH is the change amount of the accelerator operation amount ACP per unit time. Also, the threshold value ACPHref is a predetermined value. As this threshold value ACPHref, based on the accelerator change amount ACPH being less than the threshold value ACPHref, the magnitude of the value is set so that it can be determined that the accelerator change amount ACPH is small enough to determine that the vehicle 500 is about to stop.

[0038] When it is determined that the accelerator change amount ACPH is less than the threshold value ACPHref (S140: YES), the CPU 110 executes the process of S150. In the process of S150, the CPU 110 determines whether the continuous time TP, which is the time during which all positive determinations were made in the processes of S120, S130, and S140, is greater than or equal to the threshold value TPref. The threshold value TPref is a predetermined value. As this threshold value TPref, based on the continuous time TP being greater than or equal to the threshold value TPref, the magnitude of the value is set so that it can be determined that the positive determinations in the processes of S120, S130, and S140 are not temporary but are stably made.

[0039] When it is determined that the continuous time TP is greater than or equal to the threshold value TPref (S150: YES), the CPU 110 executes the above-described pressure reduction process by performing the process of S160. Note that when the CPU 110 completes the process of S160 or makes a negative determination in each of the processes of S120, S130, S140, and S150, the series of processes shown in FIG. 2 is temporarily terminated.

[0040] <Operation and Effect> The operation and effect of this embodiment will be described. (1) When the internal combustion engine 10 is in the idle state and the vehicle 500 is stopped, the above pressure reduction process is executed. Also, when all positive determinations are made in the processes of S120, S130, S140, and S150 shown in FIG. 2, that is, when it is immediately before the vehicle 500 stops and there is a high possibility of stopping soon, the above pressure reduction process is also executed. When the pressure reduction process is executed, the opening degree of the throttle valve 28 becomes smaller than before the execution of the pressure reduction process, so that the pressure in the surge tank 60 decreases. When the pressure in the surge tank 60 decreases, the hydrogen gas accumulated in the crankcase 19 is discharged to the surge tank 60 through the PCV passage 35 or the like, so that the hydrogen concentration in the crankcase 19 decreases. Therefore, the hydrogen concentration in the crankcase 19 can be decreased without providing a ventilation fan.

[0041] (2) When the internal combustion engine 10 is in the idle state and the vehicle 500 is stopped, or when it is immediately before the vehicle 500 stops and there is a high possibility of stopping soon, the above pressure reduction process is executed. Therefore, when the vehicle 500 stops and then the operation of the internal combustion engine 10 is stopped, the hydrogen concentration in the crankcase 19 is decreased. Therefore, when the internal combustion engine 10 is being maintained, it is possible to suppress the leakage of the hydrogen gas in the crankcase 19 into the atmosphere.

[0042] <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 range where there is no technical contradiction.

[0043] ·In order to determine that the target output Pe is in a state less than a predetermined value, each process of S100 and S110 shown in FIG. 2 and each process of S120, S130, S140, and S150 are performed, but it may be determined under other conditions.

[0044] ·By comparing a predetermined value determined in advance with the target output Pe, it may be determined that the target output Pe is in a state less than the predetermined value. ·As the pressure reduction process, the process of reducing the opening degree of the throttle valve 28 is executed, but other processes may be performed.

[0045] ·The process of S200 shown in FIG. 3 may be executed as the pressure reduction process. That is, as the pressure reduction process, a valve timing change process of advancing the current valve timing of the intake valve 81 by a specified value β may be executed. The specified value β is the amount of advance of the valve opening timing of the intake valve 81 required for the pressure in the surge tank 60 to drop to the pressure required for discharging blow-by gas through the PCV passage 35, and is a predetermined value. The CPU 110 performs this valve timing change process through the control of the intake side valve timing variable mechanism 85. When the valve opening timing of the intake valve 81 is advanced in this way, the amount of air inhaled into the cylinder from the surge tank 60 and the intake manifold 29 increases during the intake stroke, so the amount of air in the surge tank 60 decreases. When the amount of air in the surge tank 60 decreases, the pressure in the surge tank 60 decreases. Therefore, also in this modification example, the pressure in the surge tank 60 can be decreased. When applying this modification example, as the variable valve mechanism provided in the drive system of the intake valve 81, any mechanism having a mechanism capable of changing the valve opening timing of the intake valve 81 may be used.

[0046] ·The process of S300 shown in FIG. 4 may be executed as the pressure reduction process. That is, as the pressure reduction process, a process of reducing the supercharging pressure of the current supercharger 24 by a prescribed value γ may be executed. The prescribed value γ is the amount of reduction in the supercharging pressure required for the pressure in the surge tank 60 to drop to the pressure necessary for discharging blow-by gas through the PCV passage 35, and is a predetermined value. The CPU 110 executes a process of reducing the supercharging pressure by the prescribed value γ by increasing the opening degree of the WGV 93 through adjusting the opening degree of the WGV 93 and increasing the amount of exhaust gas bypassing the turbine wheel 24T. When the supercharging pressure thus decreases, the pressure decreases in the intake passage downstream of the compressor wheel 24C, so the pressure in the surge tank 60 also decreases. Therefore, also in this modification example, the pressure in the surge tank 60 can be decreased.

[0047] Note that the supercharging pressure may be reduced in other modes. For example, when the supercharger 24 is a variable displacement type supercharger equipped with a nozzle vane, the supercharging pressure may be reduced by the prescribed value γ by changing the opening degree of the nozzle vane. Also, for example, when the supercharger 24 is an electric supercharger that rotates the compressor wheel 24C with an electric motor, the supercharging pressure may be reduced by the prescribed value γ by changing the rotational speed of the electric motor.

[0048] ·As the above-described pressure reduction process, at least one of the process of S160 shown in FIG. 2, the process of S200 shown in FIG. 3, and the process of S300 shown in FIG. 4 may be executed. Note that the expression “at least one” used in this specification means “one or more” of the desired options. As an example, the expression “at least one” used in this specification means “only one option” or “both of the two options” if the number of options is two. As another example, the expression “at least one” used in this specification means “only one option” or “any combination of two or more options” if the number of options is three or more.

[0049] · Although the PCV passage 35 is connected to the surge tank 60, if the connection site is downstream of the throttle valve 28 in the intake passage, the connection site may be changed as appropriate. · The internal combustion engine 10 may be provided with only one of the port injection valve 83 or the in-cylinder injection valve 84.

[0050] · When the process of S300 shown in FIG. 4 is not executed, it is not essential for the internal combustion engine 10 to be provided with the supercharger 24. · When the process of S200 shown in FIG. 3 is not executed, it is not essential for the internal combustion engine 10 to be provided with the intake-side valve timing variable mechanism 85.

[0051] · The internal combustion engine 10 may not be provided with the exhaust-side valve timing variable mechanism 86. · The control device is not limited to one including the CPU 110 and the memory 120 and executing software processing. For example, at least a part of what was software-processed in the above embodiment may be provided with a dedicated hardware circuit such as an ASIC that performs hardware processing. That is, the control device may have any of the following configurations (a) to (c). (a) It includes a processing device that executes all of the above processes according to a program, and a program storage device such as a ROM that stores the program. (b) It includes a processing device and a program storage device that execute a part of the above processes according to a program, and a dedicated hardware circuit that executes the remaining processes. (c) It includes a dedicated hardware circuit that executes all of the above processes. Here, the software execution device including the processing device and the program storage device, and the dedicated hardware circuit may be one or any plurality.

[0052] <Appendix> The above embodiment includes the configurations described in the following appendix. [Appendix 1] A control device applied to an internal combustion engine using hydrogen as fuel, the internal combustion engine having a communication passage communicating a crankcase and an intake passage, and performing control to make the air-fuel ratio of the air-fuel mixture smaller when the target output of the internal combustion engine is large than when it is small. When the target output is less than a predetermined value, a pressure reduction process for reducing the pressure in the intake passage is executed. The pressure reduction process is a process for reducing the pressure in the intake passage compared to before the execution of the pressure reduction process. A control device for an internal combustion engine.

[0053] [Appendix 2] The intake passage has a throttle valve, and the pressure reduction process is a process for reducing the opening degree of the throttle valve. The control device for an internal combustion engine according to [Appendix 1].

[0054] [Appendix 3] The internal combustion engine has a variable valve mechanism for changing the valve opening timing of the intake valve, and the pressure reduction process is a process for advancing the valve opening timing. The control device for an internal combustion engine according to [Appendix 1] or [Appendix 2].

[0055] [Appendix 4] The internal combustion engine has a supercharger for supercharging the air in the intake passage, and the pressure reduction process is a process for reducing the supercharging pressure of the supercharger. The control device for an internal combustion engine according to any one of [Appendix 1] to [Appendix 3].

Explanation of Signs

[0056] 10…Internal combustion engine 19…Crankcase 20…Intake pipe 24…Supercharger 28…Throttle valve 29…Intake manifold 32…Suction passage 34…PCV valve 35…PCV passage 36…Bypass passage 37…Atmosphere introduction passage 40…Ejector 60…Surge tank 81…Intake valve 82…Exhaust valve 83…Port injection valve 84…In-cylinder injection valve 85…Intake-side valve timing variable mechanism 90…Exhaust passage 92…Bypass passage 93…Wastegate valve (WGV) 100…Control device 110…Central processing unit (CPU) 120…Memory 500…Vehicle

Claims

1. Applied to an internal combustion engine that uses hydrogen as fuel, the internal combustion engine has a communication passage that communicates the crankcase and the intake passage, and a variable valve mechanism that changes the valve opening timing of the intake valve. The control device executes control to make the air-fuel ratio of the air-fuel mixture smaller when the target output of the internal combustion engine is large than when it is small, and when the target output is less than a predetermined value, it executes a pressure reduction process to reduce the pressure in the intake passage, wherein the pressure reduction process is a process of reducing the pressure in the intake passage compared to before the execution of the pressure reduction process by advancing the valve opening timing. A control device for an internal combustion engine.

2. Applied to an internal combustion engine that uses hydrogen as fuel, the internal combustion engine has a communication passage that communicates the crankcase and the intake passage, and a supercharger that supercharges the air in the intake passage. The control device executes control to make the air-fuel ratio of the air-fuel mixture smaller when the target output of the internal combustion engine is large than when it is small, and when the target output is less than a predetermined value, it executes a pressure reduction process to reduce the pressure in the intake passage, wherein the pressure reduction process is a process of reducing the pressure in the intake passage compared to before the execution of the pressure reduction process by reducing the supercharging pressure of the supercharger. A control device for an internal combustion engine.

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