Vehicle control device

Abstract

To reduce hydrogen concentration in a crank chamber without providing a ventilation fan.SOLUTION: A control device for controlling a vehicle on which an internal combustion engine having a communication passage connecting a crank chamber to a downstream passage which is a downstream side portion with respect to a throttle valve in an intake passage and using hydrogen as fuel is mounted executes: processing (step S10) for calculating hydrogen concentration J in the crank chamber on the basis of an operation state of the internal combustion engine; and processing (step S40, step S110) for reducing, when a condition including the fact that the hydrogen concentration J is equal to or higher than a determination value JS is established (step S20; YES), a pressure in the downstream passage as compared with a pressure at the time when the condition is established.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] This invention relates to a control device for a vehicle.

Background Art

[0002] Patent Document 1 discloses an internal combustion engine using hydrogen as fuel and its control device. The internal combustion engine has a crank chamber, a ventilation passage, and a ventilation fan. The ventilation passage communicates the crank chamber with the outside of the internal combustion engine. The ventilation fan is located in the middle of the ventilation passage. Hydrogen gas leaking from the cylinder accumulates in the crank chamber. When the hydrogen concentration in the crank chamber becomes high, the control device drives the ventilation fan. Then, the hydrogen gas is discharged from the crank chamber.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When a ventilation fan is provided for discharging hydrogen gas as in the technology of Patent Document 1, space is required around the internal combustion engine for mounting various equipment related to the ventilation fan. Accordingly, the space constraints increase when mounting the internal combustion engine in a vehicle. Therefore, a technology that can reduce the hydrogen concentration in the crank chamber without providing such a ventilation fan is desired.

Means for Solving the Problems

[0005] A vehicle control device for solving the above problems has a communication passage connecting from a crank chamber to a downstream passage which is a portion downstream of a throttle valve in an intake passage, and controls a vehicle equipped with an internal combustion engine using hydrogen as fuel. The device executes a hydrogen concentration calculation process for calculating the hydrogen concentration in a specific portion of a target area combining the crank chamber and the communication passage based on the operating state of the internal combustion engine, and a pressure reduction process for reducing the pressure of the downstream passage when a condition including that the hydrogen concentration is equal to or higher than a predetermined determination value is satisfied, compared with the time when the condition is satisfied.

[0006] In the above configuration, when the pressure reduction process is executed, the pressure of the downstream passage decreases. When the pressure of the downstream passage decreases, hydrogen gas accumulated in the crank chamber is discharged into the intake passage through the communication passage together with other gases. Therefore, the hydrogen concentration in the crank chamber decreases. Thus, in the above configuration, the hydrogen concentration in the crank chamber can be decreased without providing a ventilation fan.

[0007] The vehicle control device has a storage device and an execution device. The storage device stores in advance mapping data defining a mapping that outputs, as an output variable, a variable indicating the hydrogen concentration when a plurality of input variables are input, and the mapping is learned by machine learning. The mapping includes, as one of the plurality of input variables, a variable indicating the pressure of the downstream passage. The execution device may execute, as the hydrogen concentration calculation process, an acquisition process for acquiring the values of the input variables, and a calculation process for calculating the value of the output variable by inputting the values of the input variables acquired by the acquisition process into the mapping.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0009] (First Embodiment) Hereinafter, a first embodiment of a vehicle control device will be described with reference to the drawings. <Overall Configuration of Vehicle> As shown in FIG. 1, the vehicle 90 includes an internal combustion engine 10, a drive clutch 81, a motor generator 82, a transmission unit 80, a hydraulic mechanism 86, a differential 71, a plurality of axles 73, a plurality of drive wheels 72, an inverter 78, and a battery 79.

[0010] The internal combustion engine 10 is a drive source of the vehicle 90. Details of the internal combustion engine 10 will be described later. The internal combustion engine 10 has a crankshaft 7. The motor generator 82 is a drive source of the vehicle 90. The motor generator 82 has both functions of an electric motor and a generator. The motor generator 82 has a stator 82C, a rotor 82B, and a rotating shaft 82A. The rotor 82B is rotatable with respect to the stator 82C. The rotating shaft 82A rotates integrally with the rotor 82B. The motor generator 82 is electrically connected to the battery 79 via the inverter 78. The battery 79 exchanges electric power with the motor generator 82. The inverter 78 performs DC-AC conversion.

[0011] The drive clutch 81 is interposed between the internal combustion engine 10 and the motor generator 82. The drive clutch 81 becomes connected or disconnected according to the hydraulic pressure from the hydraulic mechanism 86. In the connected state, the drive clutch 81 connects the crankshaft 7 and the rotating shaft 82A of the motor generator 82. In the disconnected state, the drive clutch 81 disconnects the crankshaft 7 and the rotating shaft 82A of the motor generator 82. When the drive clutch 81 is in the connected state, the motor generator 82 can apply torque to the crankshaft 7.

[0012] The transmission unit 80 has a torque converter 83 and an automatic transmission 85. The torque converter 83 has a pump impeller 83A, a turbine liner 83B, and a lock-up clutch 84. The torque converter 83 is a fluid coupling having a torque amplification function. The pump impeller 83A rotates integrally with the rotating shaft 82A of the motor generator 82. The turbine liner 83B rotates integrally with the input shaft of the automatic transmission 85. The lock-up clutch 84 assumes a connected state or a disconnected state according to the hydraulic pressure from the hydraulic mechanism 86. In the connected state, the lock-up clutch 84 connects the pump impeller 83A and the turbine liner 83B. In the disconnected state, the lock-up clutch 84 disconnects the pump impeller 83A and the turbine liner 83B.

[0013] The automatic transmission 85 is a stepped transmission whose gear ratio is switched in multiple steps by switching gears. The gears are switched according to the hydraulic pressure from the hydraulic mechanism 86. The output shaft of the automatic transmission 85 is connected to the left and right axles 73 via a differential 71. The axles 73 transmit the driving force to the drive wheels 72. The differential 71 allows a difference in rotational speed to occur between the left and right axles 73. The drive clutch 81, the motor generator 82, and the transmission unit 80 are housed in a single case. In the above series of power transmission systems, the internal combustion engine 10 and the motor generator 82 can apply torque to the axles 73 and thus to the drive wheels 72 via the transmission unit 80.

[0014] The vehicle 90 has a vehicle speed sensor 58, an accelerator sensor 59, and a battery sensor 60. The vehicle speed sensor 58 detects the traveling speed of the vehicle 90 as the vehicle speed SP. The accelerator sensor 59 detects the depression amount of the accelerator pedal in the vehicle 90 as the accelerator operation amount ACC. The battery sensor 60 detects battery information B such as the current, voltage, and temperature of the battery 79. Each of the above sensors repeatedly transmits a signal corresponding to the information it has detected to a control device 100 described later.

[0015] <Schematic Configuration of Internal Combustion Engine> As shown in FIG. 3, the internal combustion engine 10 has an oil pan 13, a cylinder block 12, a cylinder head 18, and a cylinder head cover. In the drawings, the illustration of the cylinder head cover is omitted. The oil pan 13 stores oil. The cylinder block 12 is located above the oil pan 13. The cylinder head 18 is located above the cylinder block 12. The cylinder head cover covers the cylinder head 18 from above. Note that the lower portion of the cylinder block 12 may also be referred to as a crankcase.

[0016] The internal combustion engine 10 has a plurality of cylinders 2, a plurality of pistons 6, a plurality of connecting rods 14, a crank chamber 11, and a crankshaft 7. In FIG. 3, only one of the plurality of cylinders 2 is shown. The same applies to the pistons 6 and the connecting rods 14. The number of cylinders 2 is four. The cylinder 2 is a space partitioned in the cylinder block 12. In the cylinder 2, a mixture of intake air and fuel burns. The crank chamber 11 is located below the cylinder 2. The crank chamber 11 is a space partitioned by the lower portion of the cylinder block 12 and the oil pan 13. The crank chamber 11 communicates with each cylinder 2. The crank chamber 11 houses the crankshaft 7. The piston 6 is provided for each cylinder 2. The piston 6 is located within the cylinder 2. The piston 6 reciprocates within the cylinder 2. The piston 6 is connected to the crankshaft 7 via the connecting rod 14. The crankshaft 7 rotates according to the operation of the piston 6.

[0017] The internal combustion engine 10 has a plurality of spark plugs 19 and a plurality of fuel injection valves 17. In FIG. 3, only one of the plurality of spark plugs 19 is shown. The same applies to the fuel injection valves 17. The spark plugs 19 are provided for each cylinder 2. The spark plugs 19 are attached to the cylinder head 18. The tip of the spark plug 19 is located inside the cylinder 2. The spark plug 19 ignites the air-fuel mixture inside the cylinder 2. The fuel injection valves 17 are provided for each cylinder 2. The fuel injection valves 17 are attached to the cylinder head 18. The tip of the fuel injection valve 17 is located inside the cylinder 2. The fuel injection valve 17 injects fuel directly into the cylinder 2 without passing through the intake passage 3 described later. The fuel injection valve 17 injects hydrogen as fuel.

[0018] The internal combustion engine 10 has an intake passage 3, an air cleaner 23, an intercooler 65, and a throttle valve 29. The intake passage 3 is a passage for introducing intake air into the cylinder 2. The intake passage 3 is connected to each cylinder 2. The air cleaner 23 filters the intake air taken into the intake passage 3. The intercooler 65 is located on the downstream side of the air cleaner 23 in the intake passage 3. The intercooler 65 cools the intake air. The throttle valve 29 is located on the downstream side of the intercooler 65 in the intake passage 3. The throttle valve 29 can adjust its opening degree. The intake air amount GA changes according to the opening degree of the throttle valve 29 (hereinafter referred to as the throttle opening degree). The throttle opening degree is changed by an electric motor.

[0019] The internal combustion engine 10 has an exhaust passage 8. The exhaust passage 8 is a passage for discharging exhaust from the cylinder 2. The exhaust passage 8 is connected to each cylinder 2. The internal combustion engine 10 has a plurality of intake valves 15, an intake valve drive mechanism 25, a plurality of exhaust valves 16, and an exhaust valve drive mechanism 26. In FIG. 3, only one of the plurality of intake valves 15 is shown. The same applies to the exhaust valve 16. The intake valve 15 is provided for each cylinder 2. The intake valve 15 is located at the connection port with the cylinder 2 in the intake passage 3. The intake valve drive mechanism 25 has an intake camshaft and an intake valve variable device. In response to the operation of the intake camshaft, the intake valve 15 opens and closes the connection port of the intake passage 3. The intake valve variable device changes the opening and closing timing of the intake valve 15. The exhaust valve 16 is provided for each cylinder 2. The exhaust valve 16 is located at the connection port with the cylinder 2 in the exhaust passage 8. The exhaust valve drive mechanism 26 has an exhaust camshaft and an exhaust valve variable device. In response to the operation of the exhaust camshaft, the exhaust valve 16 opens and closes the connection port of the exhaust passage 8. The exhaust valve variable device changes the opening and closing timing of the exhaust valve 16.

[0020] The internal combustion engine 10 has a supercharger 40. The supercharger 40 is provided straddling the intake passage 3 and the exhaust passage 8. The supercharger 40 has a compressor wheel 41 and a turbine wheel 42. The compressor wheel 41 is located between the air cleaner 23 and the intercooler 65 in the intake passage 3. The turbine wheel 42 is located in the middle of the exhaust passage 8. The turbine wheel 42 rotates according to the flow of the exhaust gas. The compressor wheel 41 rotates integrally with the turbine wheel 42. At this time, the compressor wheel 41 compresses and sends out the intake air. That is, the compressor wheel 41 supercharges the intake air.

[0021] The supercharger 40 has a bypass passage 64 and a waste gate valve (hereinafter referred to as WGV) 63. The bypass passage 64 connects the upstream portion and the downstream portion of the exhaust passage 8 with respect to the turbine wheel 42. That is, the bypass passage 64 is a passage that bypasses the turbine wheel 42. The WGV 63 is located at the downstream end of the bypass passage 64. In FIG. 3, for the sake of convenience, the WGV 63 is shown in the middle of the bypass passage 64. The WGV 63 can be adjusted in opening degree by an actuator. As the opening degree of the WGV 63 increases, the amount of exhaust gas flowing through the bypass passage 64 while bypassing the turbine wheel 42 increases. At the same time, the rotational speeds of the turbine wheel 42 and the compressor wheel 41 decrease. At the same time, the supercharging pressure QP, which is the pressure of the gas on the downstream side of the compressor wheel 41 in the intake passage 3, decreases. When the WGV 63 is fully open, supercharging by the compressor wheel 41 stops.

[0022] The internal combustion engine 10 has a blow-by gas treatment mechanism for returning the blow-by gas in the crankcase 11 to the intake passage 3. The blow-by gas is the gas that leaks from the cylinder 2 into the crankcase 11 during the compression stroke or the combustion stroke. The blow-by gas treatment mechanism has a first connection passage 51, a second connection passage 52, and a PCV valve 53. The portion of the intake passage 3 on the downstream side of the throttle valve 29 is referred to as a downstream passage 3A. The first connection passage 51 connects the crankcase 11 to the downstream passage 3A. The second connection passage 52 connects the crankcase 11 to the portion of the intake passage 3 upstream of the compressor wheel 41 as viewed from the compressor wheel 41. The PCV valve 53 is located in the middle of the first connection passage 51. The PCV valve 53 is a differential pressure valve. The PCV valve 53 opens when the pressure of the gas in the downstream passage 3A (hereinafter referred to as the downstream pressure) LP becomes lower than the pressure of the gas in the crankcase 11 (hereinafter referred to as the pressure of the crankcase 11) RP. When the PCV valve 53 opens, the inflow of blow-by gas from the crankcase 11 into the downstream passage 3A is permitted.

[0023] For example, when the supercharging pressure QP of the intake air by the compressor wheel 41 is low or when supercharging by the compressor wheel 41 is not being performed, the downstream pressure LP becomes lower than the pressure RP in the crank chamber 11. In this case, as described above, when the PCV valve 53 opens, the blow-by gas in the crank chamber 11 is discharged to the downstream passage 3A through the first communication passage 51. On the other hand, for example, when the supercharging pressure QP is high, the magnitude relationship between the downstream pressure LP and the pressure RP in the crank chamber 11 is reversed from the above, so the PCV valve 53 closes. In this case, the blow-by gas in the crank chamber 11 is discharged into the intake passage 3 through the second communication passage 52. However, the discharge amount of the blow-by gas at this time is limited.

[0024] The internal combustion engine 10 includes a crank position sensor 35, a concentration sensor 32, an air flow meter 31, a supercharging pressure sensor 37, and an intake pressure sensor 36. The crank position sensor 35 is located near the crankshaft 7. The crank position sensor 35 detects the rotational position CR of the crankshaft 7. The concentration sensor 32 is attached to the crank chamber 11. The concentration sensor 32 detects the hydrogen concentration J, which is the concentration of hydrogen gas in the crank chamber 11. The hydrogen concentration J is, specifically, the content [%] of hydrogen gas in the crank chamber 11. The air flow meter 31 is located in the intake passage 3 between the air cleaner 23 and the compressor wheel 41. The air flow meter 31 detects the intake air amount GA. The supercharging pressure sensor 37 is located in the intake passage 3 between the intercooler 65 and the throttle valve 29. The supercharging pressure sensor 37 detects the above-described supercharging pressure QP. The intake pressure sensor 36 is located in the downstream passage 3A. The intake pressure sensor 36 detects the above-described downstream pressure LP. Each of these sensors repeatedly transmits a signal corresponding to the information it has detected to a control device 100 described later.

[0025] <Schematic Configuration of Control Device> As shown in FIG. 1, the vehicle 90 has a control device 100. The control device 100 can be configured as one or more processors that execute various processes according to a computer program (software). Note that the control device 100 may be configured as a circuitry including one or more dedicated hardware circuits such as an application specific integrated circuit (ASIC) that executes at least a part of the various processes, or a combination thereof. The processor includes a CPU 111 and memories such as a RAM and a ROM 112. The memory stores program codes or instructions configured to cause the CPU 111 to execute processes. The memory, that is, the computer-readable medium includes any available medium that can be accessed by a general-purpose or dedicated computer. The CPU 111 and the ROM 112 constitute an execution device. Note that the CPU 111 has a time measurement function. The control device 100 has a storage device 113 that is an electrically rewritable non-volatile memory.

[0026] The control device 100 repeatedly receives detection signals from various sensors attached to the vehicle 90. Specifically, the control device 100 receives detection signals for the following respective parameters.

[0027] · The rotational position CR of the crankshaft 7 detected by the crank position sensor 35 · The hydrogen concentration J detected by the concentration sensor 32 · The intake air amount GA detected by the air flow meter 31 · The downstream pressure LP detected by the intake pressure sensor 36 · The supercharging pressure QP detected by the supercharging pressure sensor 37 · The vehicle speed SP detected by the vehicle speed sensor 58 · The accelerator operation amount ACC detected by the accelerator sensor 59 · The battery information B detected by the battery sensor 60 The CPU 111 calculates the following parameters at any time based on the detection signals received from various sensors. The CPU 111 calculates the engine rotation speed NE, which is the rotation speed of the crankshaft 7, based on the rotational position CR of the crankshaft 7. Further, the CPU 111 calculates the engine load factor KL based on the engine rotation speed NE and the intake air amount GA. The engine load factor KL is a parameter that determines the amount of air filled in the cylinder 2, and is a value obtained by dividing the amount of air flowing into one cylinder 2 per combustion cycle by the reference air amount. The reference air amount changes according to the engine rotation speed NE. One combustion cycle is a series of periods during which one cylinder 2 undergoes an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke once each. The CPU 111 calculates the charging rate of the battery 79 based on the battery information B. The charging rate of the battery 79 is a value obtained by dividing the remaining capacity of the battery 79 by the full charge capacity of the battery 79.

[0028] The CPU 111 calculates a required driving force, which is a required value of the driving force necessary for the vehicle 90 to travel, based on the accelerator operation amount ACC, the vehicle speed SP, etc. Then, the CPU 111 calculates an engine target torque, which is the target torque of the internal combustion engine 10, and a motor target torque, which is the target torque of the motor generator 82, based on the required driving force. Then, the CPU 111 controls the internal combustion engine 10 and the motor generator 82 based on the calculated respective target torques. Further, the CPU 111 controls the automatic transmission 85, the drive clutch 81, and the lock-up clutch 84 according to the running state of the vehicle 90. That is, the CPU 111 switches the gear stage of the automatic transmission 85, switches the engaged / disengaged state of the drive clutch 81, and switches the engaged / disengaged state of the lock-up clutch 84. At that time, the CPU 111 adjusts the hydraulic pressure for each control target by controlling the hydraulic mechanism 86. In this way, the CPU 111 controls various parts of the vehicle 90.

[0029] When controlling the internal combustion engine 10, the CPU 111 sets control target values for various parts of the internal combustion engine 10 based on, in addition to the above-described engine target torque, the engine rotational speed NE, the engine load factor KL, and the like. Then, the CPU 111 controls various parts of the internal combustion engine 10 based on those control target values. For example, the CPU 111 adjusts the throttle opening to match the target opening, injects fuel of a target injection amount from the fuel injection valve 17, or ignites the ignition plug 19 at the target ignition timing. The CPU 111 burns the air-fuel mixture in each cylinder 2 by fuel injection from the fuel injection valve 17 and ignition by the ignition plug 19. Further, the CPU 111 adjusts the opening of the WGV 63 so that the supercharging pressure QP of the intake air by the compressor wheel 41 becomes the target supercharging pressure, or drives the intake valve variable device so that the opening / closing timing of the intake valve 15 matches the target timing. When performing supercharging of the intake air, the CPU 111 fully opens the throttle opening. In the following description, a detailed explanation of the point that the CPU 111 sets each control target value when executing various processes will be omitted.

[0030] The CPU 111 controls various parts of the vehicle 90 by switching the driving mode of the vehicle 90 between a hybrid mode and an electric mode according to the situation. In the electric mode, the CPU 111 stops the internal combustion engine 10 while driving the motor generator 82. That is, in the electric mode, the CPU 111 uses only the motor generator 82 as a driving source. Note that the electric mode includes a normal electric mode in which the drive clutch 81 is disengaged and a motor ring mode in which the drive clutch 81 is engaged. The motor ring mode is dedicated to the avoidance processing described later. On the other hand, in the hybrid mode, the CPU 111 drives both the internal combustion engine 10 and the motor generator 82 and engages the drive clutch 81. Then, in the hybrid mode, the CPU 111 uses both the internal combustion engine 10 and the motor generator 82 as driving sources. In the hybrid mode, the CPU 111 may cause the motor generator 82 to perform regenerative power generation by the power of the internal combustion engine 10. Whether in the electric mode or the hybrid mode, the CPU 111 basically engages the lock-up clutch 84 during the running of the vehicle 90.

[0031] When the charging rate of the battery 79 has sufficient margin, for example, the CPU 111 selects the electric mode when the required driving force is relatively small, and selects the hybrid mode when the required driving force is relatively large. Examples of the case where the required driving force is small include when the vehicle 90 starts and when driving under a light load with a small forward acceleration. As described above, there are two types of electric modes: the normal electric mode and the motoring mode. The required driving force that serves as the switching threshold between the hybrid mode and the normal electric mode is referred to as the normal threshold. The required driving force that serves as the switching threshold between the hybrid mode and the motoring mode is referred to as the motoring threshold. The motoring threshold is set to a value larger than the minimum value of the required driving force for which supercharging is required by the internal combustion engine 10, and is determined in advance by experiments or simulations, for example. The ROM 112 stores the normal threshold and the motoring threshold in advance. As described above, the motoring mode is dedicated to avoidance processing. Therefore, except during the execution of avoidance processing, the CPU 111 does not refer to the motoring threshold regarding the switching between the hybrid mode and the electric mode.

[0032] <Outline of Avoidance Processing> In the internal combustion engine 10, for example, when the supercharging pressure QP of the intake air is high, the downstream pressure LP tends to increase. In this case, since the PCV valve 53 closes, it is difficult to discharge the blow-by gas from the crankcase 11 to the downstream passage 3A through the first communication passage 51. Along with this, hydrogen gas contained in the blow-by gas tends to accumulate in the crankcase 11. If the situation where hydrogen gas accumulates in the crankcase 11 continues, there is a risk that the hydrogen concentration J in the crankcase 11 will increase to a level where ignition is possible. Note that even when the supercharging pressure QP is low or when the throttle valve 29 is at an opening close to fully open during non-supercharging, the hydrogen concentration J in the crankcase 11 may increase depending on the situation. The CPU 111 is capable of executing avoidance processing as a process for avoiding an increase in the hydrogen concentration J in the crankcase 11. The CPU 111 realizes each process of the avoidance processing by executing the program stored in the ROM 112.

[0033] As part of the avoidance process, the CPU 111 is capable of executing hydrogen concentration calculation processing. In the hydrogen concentration calculation processing, the CPU 111 calculates the current hydrogen concentration J in the crankcase 11. Here, the hydrogen concentration J in the crankcase 11 is related to various parameters representing the operating state of the internal combustion engine 10, such as the fuel injection amount, the downstream pressure LP, and the pressure RP in the crankcase 11. Therefore, the hydrogen concentration J related to these parameters is also one of the parameters representing the operating state of the internal combustion engine 10. In the present embodiment, the CPU 111 calculates the current value of the hydrogen concentration J, which is a parameter representing the operating state of the internal combustion engine 10, based on the detection signal of the concentration sensor 32 that detects the hydrogen concentration J itself.

[0034] As part of the avoidance process, the CPU 111 is capable of executing pressure reduction processing. The CPU 111 performs pressure reduction processing when specific conditions are met. In the present embodiment, the specific conditions are that all of the following three items are satisfied.

[0035] (N1) The current hydrogen concentration J in the crankcase 11 is equal to or greater than the determination value JS. (N2) The vehicle 90 is traveling in hybrid mode. (N3) The charge rate of the battery 79 is equal to or greater than the specified charge rate.

[0036] The determination value JS is a value lower than the lower limit value of the flammable concentration range of hydrogen gas. The determination value JS is determined in advance by, for example, experiments or simulations as the hydrogen concentration J for which it is necessary to take measures to reduce the hydrogen concentration J before the hydrogen concentration J increases to the lower limit value. Here, as will be described later, when the pressure reduction processing and a series of subsequent processes are performed, the output of the internal combustion engine 10 decreases. The CPU 111 will cover this decrease in output with the motor generator 82. The above-mentioned specified charge rate is determined in advance by, for example, experiments or simulations as a value at which the charge rate of the battery 79 does not fall below the allowable lower limit value even if the decrease in the output of the internal combustion engine 10 associated with the above series of processes is covered by the motor generator 82. The ROM 112 stores the specific conditions in advance, including the determination value JS and the specified charge rate.

[0037] When performing the pressure reduction process, the CPU 111 reduces the downstream pressure LP compared to the time when a specific condition is satisfied. The CPU 111 can execute two processes with different contents as this pressure reduction process.

[0038] When the CPU 111 can switch the drive mode of the vehicle 90 to the motoring mode at the time when a specific condition is satisfied, the CPU 111 performs a first reduction process as the pressure reduction process. Substantially, the first reduction process is a process of switching the drive mode of the vehicle 90 from the hybrid mode to the motoring mode. As described above, the motoring mode is a type of electric mode. In the motoring mode of the present embodiment, the throttle opening in the internal combustion engine 10 is set to a unique value. Specifically, in the motoring mode, the throttle opening is set to a first opening V1 described later. Note that the situation in which the first reduction process is performed is a situation where the throttle opening is close to fully open during non-supercharging of the internal combustion engine 10, or a situation where the internal combustion engine 10 is supercharged, that is, the throttle opening is fully open.

[0039] In the first reduction process, the CPU 111 performs the following while maintaining the drive clutch 81 in the engaged state. That is, the CPU 111 stops the combustion of the air-fuel mixture in the internal combustion engine 10 while driving the motor generator 82 according to the required driving force. By maintaining the drive clutch 81 in the engaged state, the torque of the motor generator 82 is applied to the crankshaft 7, and the crankshaft 7 rotates. Also, in the first reduction process, the CPU 111 reduces the throttle opening, which is currently fully open or close to fully open, to the first opening V1. Here, regarding the throttle opening, the opening that is exactly in the middle between fully closed and fully open is referred to as the intermediate opening. The first opening V1 is an opening between the intermediate opening and fully closed. The first opening V1 can make the downstream pressure LP considerably smaller than the pressure RP in the crank chamber 11, and thereby, for example, is determined in advance by experiments or simulations as a value that can quickly discharge the blow-by gas through the first communication passage 51. The ROM 112 stores the first opening V1 in advance.

[0040] When the CPU 111 cannot switch the driving mode of the vehicle 90 to the motoring mode when a specific condition is satisfied, the CPU 111 performs a second reduction process as the pressure reduction process. Further, the CPU 111 performs an increase process in accordance with the second reduction process. These second reduction process and increase process are processes for switching the control in the hybrid mode from the normal control to the restricted control. Note that the restricted control prohibits supercharging in the internal combustion engine 10 and sets the upper limit opening degree of the throttle valve 29 to a second opening degree V2 described later, and then controls the internal combustion engine 10 and the motor generator 82 so as to be able to realize the required driving force. In this restricted control, the torque of the motor generator 82 for the same required driving force becomes larger than that in the normal control in which the torque of the internal combustion engine 10 is not restricted by the amount of restriction of the torque of the internal combustion engine 10. Note that, in terms of setting the motoring threshold value, the situation in which the second reduction process is performed is a situation in which the internal combustion engine 10 is supercharging. That is, the throttle opening degree is fully open.

[0041] In the second reduction process, the CPU 111 stops supercharging of the intake air by the compressor wheel 41, and further reduces the throttle opening degree in the fully open state to the second opening degree V2. The second opening degree V2 is an opening degree between the intermediate opening degree and the fully open state. The second opening degree V2 is determined in advance by, for example, experiments or simulations as an opening degree that can maintain the torque of the internal combustion engine 10 appropriately and make the downstream pressure LP smaller than the pressure RP in the crank chamber 11. The ROM 112 stores the second opening degree V2 in advance.

[0042] In the increase process, the CPU 111 increases the torque of the motor generator 82 compared to the time when the specific condition is satisfied. By doing so, the CPU 111 increases the torque input from the motor generator 82 to the axle 73. And the CPU 111 maintains the total torque input to the axle 73 from both the internal combustion engine 10 and the motor generator 82 to be the same as that at the time when the specific condition is satisfied. The ROM 112 stores a plurality of torque maps in advance as information used in the increase process. The torque map will be described. Now, assume that the internal combustion engine 10 is in supercharging and the opening degree of the WGV 63 is an arbitrary starting opening degree. And assume that the throttle opening degree is fully open. From this state, while maintaining the current ignition timing and the air-fuel ratio of the air-fuel mixture, assume that the opening degree of the WGV 63 is changed to fully open and further the throttle opening degree is changed to the second opening degree V2. The absolute value of the decrease in the torque of the internal combustion engine 10 at that time is referred to as the torque decrease value. The torque map represents the relationship between the starting opening degree of the WGV 63 and the torque decrease value. Note that the torque map is prepared for each of various combinations of ignition timing and air-fuel ratio. In the torque map, basically, the closer the starting opening degree of the WGV 63 is to fully closed, that is, the higher the supercharging pressure QP of the intake air is, the larger the torque decrease value is. The torque map is created based on, for example, experiments or simulations.

[0043] <Specific processing procedures for avoidance processing> When the CPU 111 has selected the hybrid mode as the driving mode of the vehicle 90, and the vehicle speed SP is greater than zero, and the charging rate of the battery 79 is equal to or higher than the specified charging rate, the avoidance processing is started. That is, the start condition of the avoidance processing is that the items (N2) and (N3) of the specific condition are satisfied.

[0044] As shown in FIG. 4, when the CPU 111 starts the avoidance process, it first executes the process of step S10. In step S10, the CPU 111 performs hydrogen concentration calculation processing. Specifically, the CPU 111 calculates the latest hydrogen concentration J received from the concentration sensor 32 as the current hydrogen concentration J in the crankcase 11. After that, the control device 100 advances the process to step S20.

[0045] In step S20, the CPU 111 determines whether the current hydrogen concentration J is equal to or greater than the determination value JS. If the current hydrogen concentration J is less than the determination value JS (step S20: NO), the CPU 111 ends the series of avoidance processes. In this case, if the above start condition is satisfied, the CPU 111 executes the process of step S10 again.

[0046] On the other hand, in step S20, if the current hydrogen concentration J is equal to or greater than the determination value JS (step S20: YES), the CPU 111 advances the process to step S30. Note that when the determination in step S20 is YES, the item (N1) of the specific condition is satisfied. And the specific condition is established.

[0047] In step S30, the CPU 111 determines whether the drive mode of the vehicle 90 can be switched to the motoring mode. Specifically, the CPU 111 determines whether the latest required driving force is less than the motoring threshold value. If the latest required driving force is less than the motoring threshold value, the CPU 111 determines that the drive mode of the vehicle 90 can be switched to the motoring mode (step S30: YES). In this case, the CPU 111 advances the process to step S40.

[0048] In step S40, the CPU 111 performs a first reduction process to switch the driving mode of the vehicle 90 to the motoring mode. That is, the CPU 111 stops the fuel supply and ignition to the cylinder 2 in the internal combustion engine 10. By doing so, the CPU 111 stops the combustion of the air-fuel mixture. At the same time, the CPU 111 rotationally drives the crankshaft 7 by the motor generator 82. Further, the CPU 111 reduces the throttle opening degree, which is currently fully open or nearly fully open, to the first opening degree V1. When the CPU 111 performs the first reduction process, thereafter, it continues the control in the motoring mode. That is, the CPU 111 supplies the required driving force by the motor generator 82 and rotates the crankshaft 7 by the rotation of the motor generator 82. Further, the CPU 111 maintains the throttle opening degree at the first opening degree V1. When the CPU 111 completes the first reduction process and shifts to the continuous state of the control in the motoring mode, it advances the process to step S50. Note that the CPU 111 will continue the control in the motoring mode until step S70 thereafter.

[0049] On the other hand, in step S30, when the required driving force is equal to or greater than the motoring threshold value (step S30: NO), the CPU 111 advances the process to step S110. In step S110, the CPU 111 performs a second reduction process and an increase process to switch the control in the hybrid mode from normal control to restricted control. Specifically, the CPU 111 reduces the rotational speed of the compressor wheel 41 that is currently rotating to zero by fully opening the opening degree of the WGV 63 in the internal combustion engine 10. By doing so, the CPU 111 stops the supercharging of the intake air by the compressor wheel 41. Also, the CPU 111 reduces the current fully open throttle opening degree to the second opening degree V2. The above is the second reduction process. Also, the CPU 111 increases the torque of the motor generator 82. As a specific process for that, the CPU 111 performs the following processes. First, the CPU 111 specifies the opening degree of the WGV 63 at the time when the process proceeds to step S110 as the current start opening degree. Next, the CPU 111 refers to the torque map corresponding to the ignition timing and air-fuel ratio set at the time when the process proceeds to step S110. Then, the CPU 111 calculates the torque reduction value corresponding to the current start opening degree in this torque map as the corresponding reduction value. Then, the CPU 111 calculates the added torque by adding the corresponding reduction value to the motor target torque at the time when the process proceeds to step S110. Then, the CPU 111 controls the motor generator 82 so that the added torque matches the actual torque of the motor generator 82. The above is the increase process. When the CPU 111 performs the second reduction process and the increase process, thereafter, the following is continued. That is, the CPU 111 prohibits supercharging in the internal combustion engine 10 and sets the upper limit opening degree of the throttle valve 29 to the above-described second opening degree V2, and then controls the internal combustion engine 10 and the motor generator 82 so as to realize the required driving force. When the CPU 111 completes the second reduction process and the increase process and shifts to the continued state of restricted control, the process proceeds to step S50. Note that the CPU 111 will continue the restricted control until step S70 thereafter.

[0050] In step S50, the CPU 111 calculates the current hydrogen concentration J in the crankcase 11. The processing content of this step S50 is the same as that of step S10. When the CPU 111 calculates the current hydrogen concentration J, it proceeds with the processing to step S60.

[0051] In step S60, the CPU 111 determines whether the current hydrogen concentration J is less than or equal to the end value JE. The ROM 112 stores the end value JE in advance. The end value JE is a value that the hydrogen concentration J in the crankcase 11 becomes sufficiently small and the discharge of hydrogen gas from the crankcase 11 may be stopped, and is determined in advance by, for example, experiments or simulations. The end value JE is smaller than the determination value JS. When the current hydrogen concentration J is greater than the end value JE (step S60: NO), the CPU 111 returns to the processing of step S50. Then, the CPU 111 executes the processing of step S50 again. The CPU 111 repeats the processing of steps S50 and S60 until the current hydrogen concentration J becomes less than or equal to the end value JE. Then, when the current hydrogen concentration J becomes less than or equal to the end value JE (step S60: YES), the CPU 111 proceeds with the processing to step S70. Note that the period for repeating the processing of steps S50 and S60 is about 10 seconds, for example.

[0052] In step S70, the CPU 111 ends the control or restrictive control in the motoring mode and returns the control of various parts of the vehicle 90 to the normal state. That is, thereafter, the CPU 111 controls the vehicle 90 in the hybrid mode where the torque of the internal combustion engine 10 is not restricted, or in the normal electric mode. After this, the CPU 111 ends the series of processes for the avoidance processing. After this, if the start condition for the avoidance processing is satisfied, the CPU 111 executes the processing of step S10 again.

[0053] Incidentally, the vehicle 90 may stop during the repetition of step S50 and step S60. In this case, the CPU 111 interrupts the avoidance process and performs the stop process. In the stop process, the CPU 111 continues the motoring mode until the hydrogen concentration J in the crankcase 11 decreases to the end value JE. If the CPU 111 was performing control in the motoring mode in the avoidance process, it continues the motoring mode as it is, and if it was performing limit control in the avoidance process, it shifts to the motoring mode. While continuing the motoring mode in the stop process, the CPU 111 rotates the motor generator 82 at a predetermined rotational speed. Also, in the stop process, the CPU 111 disengages the lock-up clutch 84. Incidentally, when performing the stop process, the CPU 111 may notify the passengers, for example, with a warning lamp that the rotational drive of the motor generator 82 is being continued for discharging hydrogen gas.

[0054] <Operation of the First Embodiment> Now, assume that the vehicle 90 is traveling in hybrid mode and the internal combustion engine 10 is supercharging. And assume that the hydrogen concentration J in the crankcase 11 has increased to the determination value JS due to this situation continuing for a while (step S20: YES). At this time, assume that the required driving force is so large that the driving mode of the vehicle 90 cannot be switched to the motoring mode (step S30: NO). In such a case, the CPU 111 stops the supercharging of the intake air by the compressor wheel 41 and further reduces the throttle opening to the second opening V2 (step S110). Then, the downstream pressure LP, which was positive pressure with respect to the atmospheric pressure until then, becomes negative pressure. At the same time, the downstream pressure LP becomes lower than the pressure RP in the crankcase 11. Then, hydrogen gas is discharged from the crankcase 11 to the downstream passage 3A through the first communication passage 51.

[0055] Now, as a case different from the above case, assume that when the hydrogen concentration J in the crank chamber 11 increases to the determination value JS, the required driving force does not increase as much as in the above case, and the driving mode of the vehicle 90 can be switched to the motoring mode (step S30: YES). In this case, the CPU 111 rotates the crankshaft 7 by the motor generator 82. In response to the operation of the piston 6 accompanying the rotation of this crankshaft 7, intake air is drawn into the cylinder 2. At the same time, the intake air flows through the intake passage 3. In this situation, the CPU 111 reduces the throttle opening to the first opening V1. Then, a negative pressure is generated in the downstream passage 3A, and the downstream pressure LP becomes lower than the pressure RP in the crank chamber 11. In particular, since the second opening V2 is a throttle opening that is considerably small, the negative pressure increases in the downstream pressure LP, and the difference between the downstream pressure LP and the pressure RP in the crank chamber 11 also increases. Therefore, hydrogen gas is quickly discharged from the crank chamber 11 through the first communication passage 51.

[0056] <Effects of the First Embodiment> (1-1) As described in the above operation, when the required driving force is considerably large when the specific condition is satisfied, the CPU 111 makes the downstream pressure LP negative through the stop of supercharging and the change of the throttle opening. By doing so, hydrogen gas can be discharged from the crank chamber 11. Moreover, when the downstream pressure LP becomes negative, the pressure of the gas in the cylinder 2 becomes lower. Along with that, the amount of hydrogen gas leaking from the cylinder 2 to the crank chamber 11 decreases. In this way, by discharging hydrogen gas from the crank chamber 11 and suppressing the amount of hydrogen gas newly mixed into the crank chamber 11, the hydrogen concentration J in the crank chamber 11 can be efficiently reduced. In this way, in this embodiment, the hydrogen concentration J in the crank chamber 11 can be reduced without providing a ventilation fan.

[0057] Note that when the overtime pay is stopped and the throttle opening is changed, the torque of the internal combustion engine 10 decreases. To compensate for such a decrease in torque, the CPU 111 increases the torque of the motor generator 82 by the amount of the decrease in the torque of the internal combustion engine 10. Therefore, the total torque input to the axle 73 from both the internal combustion engine 10 and the motor generator 82 can be maintained at the same level as before the overtime pay is stopped.

[0058] (1-2) As described in the above operation, when the required driving force when a specific condition is satisfied is limited to a certain level, the CPU 111 makes the drive mode of the vehicle 90 the motoring mode, thereby making the downstream passage 3A negative pressure. By doing so, hydrogen gas can be discharged from the crankcase 11. Moreover, when the drive mode of the vehicle 90 is set to the motoring mode, the fuel supply into the cylinder 2 and thus the mixing of hydrogen gas into the crankcase 11 itself disappear. Therefore, the hydrogen concentration J in the crankcase 11 can be rapidly decreased. Further, in the motoring mode, since the required driving force is entirely covered by the motor generator 82, the torque input to the axle 73 can also be maintained.

[0059] (Second Embodiment) A second embodiment of the vehicle control device will be described. In the second embodiment, the mode of the hydrogen concentration calculation process is different from that of the first embodiment. Along with this, in the second embodiment, the content of the avoidance process is partially different from that of the first embodiment. Also, the internal combustion engine 10 of the second embodiment does not have the concentration sensor 32. Except for these points, the content of the second embodiment is the same as the content of the first embodiment. Hereinafter, the parts different from the first embodiment will be mainly described, and the description of the content overlapping with the first embodiment will be simplified or omitted.

[0060] In this embodiment, in the hydrogen concentration calculation process, the CPU 111 calculates the hydrogen concentration J in the crankcase 11 using the mapping data D. The storage device 113 stores this mapping data D in advance. The mapping data D defines a mapping that outputs the value of the output variable when the values of the following five input variables are input. The input variables are the operation duration of the internal combustion engine 10 (hereinafter simply referred to as the operation time) TM, the downstream pressure LP, the engine load factor KL, the cycle injection amount U, and the previous concentration value JA. These input variables are parameters representing the operation state of the internal combustion engine 10. The output variable is the hydrogen concentration J in the crankcase 11. Note that the above operation time TM is a value that is accumulated from zero each time the drive mode of the vehicle 90 is switched to the hybrid mode. The cycle injection amount U is the total of the fuel injection amounts supplied to the four cylinders 2 in one combustion cycle. The previous concentration value JA is the hydrogen concentration J calculated when the hydrogen concentration calculation process was last executed.

[0061] As part of the hydrogen concentration calculation process, the CPU 111 is capable of executing an acquisition process and a calculation process. The CPU 111 performs these acquisition process and calculation process by executing the program stored in the ROM 112. In the acquisition process, the CPU 111 acquires the values of the above input variables. In the calculation process, the CPU 111 calculates the value of the output variable by inputting the values of the input variables acquired by the acquisition process into the mapping. Note that in this embodiment, while the hybrid mode is selected, the CPU 111 repeats the hydrogen concentration calculation process separately from the avoidance process. The CPU 111 performs the hydrogen concentration calculation process once per combustion cycle. Each time the CPU 111 performs the hydrogen concentration calculation process, it stores the calculated hydrogen concentration J in the storage device 113. At that time, the CPU 111 overwrites the old value with the new value. Therefore, the storage device 113 always holds the latest hydrogen concentration J. In step S10 of the avoidance process, the CPU 111 acquires this latest hydrogen concentration J. The same applies to step S50 of the avoidance process.

[0062] The specific processing procedure of the hydrogen concentration calculation process will be described. As shown in FIG. 2, when the CPU 111 starts the hydrogen concentration calculation process, it first executes the process of step S610. In step S610, the CPU 111 acquires the values of each input variable. Specifically, the CPU 111 acquires the latest value of the operation time TM calculated separately. Also, the CPU 111 acquires the latest downstream pressure LP received from the intake pressure sensor 36. Also, the CPU 111 acquires the latest value of the engine load factor KL calculated separately. Also, the CPU 111 calculates the cycle injection amount U based on the fuel injection amount currently set for each cylinder 2. This is equivalent to the CPU 111 acquiring the cycle injection amount U. Also, the CPU 111 acquires the previous value of the hydrogen concentration J stored in the storage device 113 as the previous concentration value JA. After that, the CPU 111 advances the process to step S620. Note that the process of step S610 is an acquisition process.

[0063] In step S620, as a pre - process for calculating the hydrogen concentration J using the mapping of the mapping data D stored in the storage device 113, the CPU 111 substitutes the values of the respective variables acquired in the process of step S610 into the input variables x(1) to x(5) for input to the mapping. Specifically, the CPU 111 substitutes the operation time TM into the input variable x(1). The CPU 111 substitutes the downstream pressure LP into the input variable x(2). The CPU 111 substitutes the engine load factor KL into the input variable x(3). The CPU 111 substitutes the cycle injection amount U into the input variable x(4). The CPU 111 substitutes the previous concentration value JA into the input variable x(5). After that, the CPU 111 advances the process to step S630.

[0064] In step S630, the CPU 111 calculates the value of the output variable y by inputting the input variables x(1) to x(5) into the mapping of the mapping data D. That is, the CPU 111 calculates the hydrogen concentration J. When the CPU 111 calculates the hydrogen concentration J, it overwrites the hydrogen concentration J currently stored in the storage device 113 with the calculated value. Note that the process of step S630 is a calculation process.

[0065] The mapping will be described in detail. The mapping in this embodiment is configured as a fully-connected feedforward neural network with a single intermediate layer. The neural network includes an input-side coefficient \(w_{Fjk}\) (\(j = 0\) to \(n\), \(k = 0\) to \(5\)) and an activation function \(h(x)\) serving as an input-side non-linear mapping that non-linearly transforms each of the outputs of the input-side linear mapping, which is a linear mapping defined by the input-side coefficient \(w_{Fjk}\). In this embodiment, the hyperbolic tangent “\(\tanh(x)\)” is exemplified as the activation function \(h(x)\). Further, the neural network includes an output-side coefficient \(w_{Sj}\) (\(j = 0\) to \(n\)) and an activation function \(f(x)\) serving as an output-side non-linear mapping that non-linearly transforms each of the outputs of the output-side linear mapping, which is a linear mapping defined by the output-side coefficient \(w_{Sj}\). In this embodiment, the hyperbolic tangent “\(\tanh(x)\)” is exemplified as the activation function \(f(x)\). Note that the value \(n\) indicates the dimension of the intermediate layer. The input-side coefficient \(w_{Fj0}\) is a bias parameter and serves as the coefficient of the input variable \(x(0)\). The input variable \(x(0)\) is defined as “1”. Also, the output-side coefficient \(w_{S0}\) is a bias parameter.

[0066] The mapping is a learned model that has been machine-learned before being implemented in the control device 100. When learning the mapping, a plurality of learning data sets required for learning are created in advance. One learning data set is composed of teacher data and training data. The teacher data is the hydrogen concentration J in the crankcase 11. The training data is the operation time TM, the downstream pressure LP, the engine load factor KL, the cycle injection amount U, and the previous concentration value JA. That is, the training data is a set of five variables that serve as inputs to the mapping. When creating the learning data set, an experiment or simulation is performed to drive the internal combustion engine 10 while variously changing the operating state of the internal combustion engine 10 for an internal combustion engine 10 having the same specifications as that mounted on the vehicle 90. Note that the internal combustion engine 10 is provided with a concentration sensor 32 for detecting the hydrogen concentration J in the crankcase 11. Then, while variously changing the operating state of the internal combustion engine 10 in the above experiment or simulation, the values of the above input variables at each timing and the value of the hydrogen concentration J detected by the concentration sensor 32 are sequentially acquired. Among the input variables, the previous concentration value JA is the value of the hydrogen concentration J detected by the concentration sensor 32 in the previous combustion cycle. For such acquired data, a combination of the operation time TM, the downstream pressure LP, the engine load factor KL, the cycle injection amount U, and the previous concentration value JA at a certain timing and the hydrogen concentration J at that time are taken as one learning data set. A plurality of such learning data sets are created. When the required number of learning data sets for learning the mapping accumulates, the mapping is learned using these plurality of learning data sets. That is, for each of the respective learning data sets, the input-side coefficient and the output-side coefficient of the mapping are adjusted so that the difference between the value of the hydrogen concentration J output by the mapping with the training data as the input and the value of the teacher data becomes equal to or less than a predetermined value. And when the above difference becomes equal to or less than the predetermined value, it is assumed that the learning is completed.

[0067] <Operation of the Second Embodiment> Explain the reason for adopting each of the above parameters as an input variable to the mapping. First, the operation time TM will be described. During the operation of the internal combustion engine 10, if the state where hydrogen gas is not discharged from the crankcase 11 continues, the hydrogen concentration J in the crankcase 11 can become higher as the operation time TM becomes longer. Also, the operation time TM is also a piece of information representing the operation state of the internal combustion engine 10, such as the progress of warm-up after the start of the internal combustion engine 10. In light of using such information for calculating the hydrogen concentration J, the operation time TM is an effective parameter.

[0068] Next, the downstream pressure LP will be described. As described in the first embodiment, the opening and closing of the PCV valve 53 is switched according to the magnitude of the downstream pressure LP. And the lower the downstream pressure LP is, the more hydrogen gas can be discharged from the crankcase 11 through the first communication passage 51. By including the downstream pressure LP as an input variable, such a relationship can be reflected in the map.

[0069] Next, the engine load ratio KL will be described. The engine load ratio KL is a parameter related to the pressure of the gas in the cylinder 2. And the higher the engine load ratio KL is, the more hydrogen gas can enter from the cylinder 2 into the crankcase 11. Also, if the engine load ratio KL is high, the pressure RP in the crankcase 11 can become high. Therefore, by including both this engine load ratio KL and the downstream pressure LP as input variables, the relationship between the magnitude relationship of the pressure RP in the crankcase 11 and the downstream pressure LP and the hydrogen concentration J can be reflected in the map.

[0070] Next, the cycle injection amount U will be described. The higher the fuel injection amount is, the higher the hydrogen concentration J in the crankcase 11 can become. By adopting the cycle injection amount U as an input variable, such a relationship can be reflected in the map.

[0071] Next, the previous concentration value JA will be described. The previous concentration value JA can be a reference value for calculating a new hydrogen concentration J. For example, by including the previous concentration value JA and the downstream pressure LP as input variables, the hydrogen concentration J output by the mapping can be a value that decreases by an amount corresponding to the downstream pressure LP with respect to the previous concentration value JA. Also, for example, by including the previous concentration value JA and the cycle injection amount U as input variables, the hydrogen concentration J output by the mapping can be a value that increases by the amount of the fuel injection amount with respect to the previous concentration value JA. Thus, by adopting the previous concentration value JA together with other parameters as input variables, it becomes possible to calculate an accurate hydrogen concentration J that reflects the history of the hydrogen concentration J up to that point.

[0072] <Effects of the Second Embodiment> In this embodiment, the hydrogen concentration J is calculated using a mapping. In this case, if appropriate teacher data and training data can be prepared, a mapping that outputs a high-precision hydrogen concentration J can be created. And if the hydrogen concentration J can be calculated using the mapping, the concentration sensor 32 can be eliminated. Therefore, an increase in cost due to providing the concentration sensor 32 can be suppressed.

[0073] (Modification Example) Note that each of the above embodiments can be implemented with the following modifications. Each embodiment and the following modification examples can be implemented in combination with each other within a technically non - conflicting range.

[0074] · The first opening V1 is not limited to the example of the above embodiment. The first opening V1 may be an opening that can make the downstream pressure LP smaller than the pressure RP in the crank chamber 11. This also applies to the second opening V2 in this regard.

[0075] · Instead of determining a target - reaching opening such as the first opening V1 when reducing the throttle opening in the first reduction process, a change amount of the throttle opening may be determined in advance. In this case, the change amount may be determined, for example, by experiment or simulation as a value necessary to make the downstream pressure LP smaller than the pressure RP in the crank chamber 11. This also applies to the second reduction process in this regard.

[0076] · In the second reduction process, it is not essential to stop the supercharging of the intake air by the compressor wheel 41. As long as the downstream pressure LP becomes smaller than the pressure RP in the crank chamber 11, even if the supercharging continues, the hydrogen gas can be discharged from the crank chamber 11 through the first communication passage 51. Therefore, in the second reduction process, without stopping the supercharging, the rotational speed of the compressor wheel 41 may be reduced by a predetermined reduction amount. The predetermined reduction amount may be determined in advance, for example, by experiment or simulation, as the reduction amount of the rotational speed of the compressor wheel 41 required to make the downstream pressure LP smaller than the pressure RP in the crank chamber 11. Then, the opening degree of the WGV 63 may be changed by an amount necessary to reduce the rotational speed of the compressor wheel 41 by the predetermined reduction amount.

[0077] · In the second reduction process, the rotational speed of the compressor wheel 41 may be gradually reduced. For example, the rotational speed of the compressor wheel 41 is first reduced to a rotational speed higher than zero. Then, when it is difficult for the decrease in the hydrogen concentration J to progress even if the rotational speed is maintained for a while, the rotational speed of the compressor wheel 41 may be set to zero to stop the supercharging.

[0078] · The content of the increase process is not limited to the example of the above embodiment. In the increase process, the torque of the motor generator 82 may be increased in accordance with the decrease in the torque of the internal combustion engine 10 in the second reduction process. By doing so, the torque input to the axle 73 can be maintained at the same magnitude as before the execution of the second reduction process.

[0079] · When increasing the torque of the motor generator 82 in the increase process, it is not essential to compensate for all of the decrease in the torque of the internal combustion engine 10. If the torque of the motor generator 82 is increased even slightly in the increase process, the decrease in the torque input to the axle 73 can be suppressed to a certain extent.

[0080] ·The content of the restriction control is not limited to the examples of the above embodiments. The content of the restriction control may be appropriately changed according to the content of the second reduction process. For example, as in the above modification example, when the supercharging is not stopped in the second reduction process, the internal combustion engine 10 may be controlled with the rotational speed of the compressor wheel 41 at the end of the second reduction process as the upper limit of the supercharging. Then, the motor generator 82 may be controlled so that the required driving force can be realized.

[0081] ·The method of determining the end of the control in the motoring mode is not limited to the examples of the above embodiments. For example, the motoring mode may be terminated when a predetermined fixed period has elapsed since the start of the motoring mode. In this case, the fixed period may be set to an appropriate value in consideration of the reduction rate of the hydrogen concentration J. The same applies to the timing of ending the restriction control. The duration until the end may be set to different lengths for the motoring mode and the restriction control.

[0082] ·The parking process may be abolished. Here, in the light load state of the internal combustion engine 10, the downstream pressure LP may be smaller than the pressure RP in the crank chamber 11. Therefore, even if no special process for discharging hydrogen gas is performed, when the internal combustion engine 10 starts and enters the light load state when the vehicle 90 has the next opportunity to run, the hydrogen gas can be discharged from the crank chamber 11 automatically.

[0083] ·The method of determining the motoring threshold can be changed as appropriate. As described in the above (1-2), in the motoring mode, since the fuel supply to the cylinder 2 itself is stopped, the hydrogen concentration J in the crank chamber 11 can be rapidly reduced. If the motoring threshold is set as large as possible, the opportunity to switch the driving mode of the vehicle 90 to the motoring mode increases. And the opportunity to obtain the effects of the above (1-2) can be increased. The motoring threshold may be variably set according to the charging rate of the battery 79.

[0084] ·Regarding the motoring mode, it is not essential to stop the combustion of the air-fuel mixture in the internal combustion engine 10. That is, in the motoring mode, the crankshaft 7 may be rotated by the motor generator 82 while continuing the combustion of the air-fuel mixture in the internal combustion engine 10. At this time, the internal combustion engine 10 is driven in a state where the torque output by the internal combustion engine 10 is limited, such as in idle operation. Idle operation means operating the internal combustion engine 10 at the minimum engine rotational speed NE at which the internal combustion engine 10 can operate independently.

[0085] ·As the pressure reduction process, the method of reducing the downstream pressure LP is not limited to the example of the above embodiment. That is, the pressure reduction process is not limited to reducing the rotational speed of the compressor wheel 41 or reducing the throttle opening. For example, as the pressure reduction process, the valve opening timing of the intake valve 15 may be advanced by the intake valve variable device. When the valve opening timing of the intake valve 15 is advanced, the amount of air inhaled from the downstream passage 3A into the cylinder 2 during the intake stroke increases, so the amount of air in the downstream passage 3A decreases. When the amount of air in the downstream passage 3A decreases, the downstream pressure LP decreases. From this point of view, for example, in the second reduction process of the above embodiment, a process such as stopping the supercharging by the compressor wheel 41 and advancing the valve opening timing of the intake valve 15 may be performed.

[0086] ·The specific conditions are not limited to the example of the above embodiment. Here, the discharge of hydrogen gas from the crankcase 11 often ends promptly. Therefore, the decrease in the charge rate of the battery 79 accompanying the execution of the motoring mode or the limit control is often small. From this perspective, for example, if the execution time of the motoring mode or the limit control is set short in advance, it is also possible to abolish item (N3). The specific conditions only need to include the item that the hydrogen concentration J in the crankcase 11 is equal to or higher than the determination value JS.

[0087] ·The method of determining the determination value JS can be changed as appropriate. The determination value JS may be set to a value at which the discharge of hydrogen gas from the crankcase 11 is required. · When calculating the hydrogen concentration J in the crank chamber 11 using a mapping, the parameters adopted as the input variables of the mapping are not limited to the examples of the above embodiments. As the input variables, other parameters may be adopted instead of or in addition to those of the above embodiments. For example, as the input variables, the rotational speed of the compressor wheel 41, the supercharging pressure QP, the engine rotational speed NE, the intake air amount GA, etc. may be adopted. The number of input variables may be reduced from that of the above embodiments. Even when changing the parameters adopted as the input variables from the examples of the above embodiments, if the downstream pressure LP is included in one of the plurality of input variables, the hydrogen concentration J can be calculated correspondingly accurately.

[0088] · When including the downstream pressure LP in one of the plurality of input variables, instead of adopting the downstream pressure LP itself as the input variable, a parameter serving as an index of the downstream pressure LP may be adopted. For example, the magnitude of the downstream pressure LP may be divided into multiple levels, and a value indicating such a level may be adopted as the input variable.

[0089] · The output variable does not have to be the hydrogen concentration J itself. Similar to the above modification example, the magnitude of the hydrogen concentration J may be divided into multiple levels, and a value indicating such a level may be adopted as the output variable. The output variable may be any variable indicating the hydrogen concentration J.

[0090] · The configuration of the mapping is not limited to the examples of the above embodiments. For example, the number of intermediate layers in the neural network may be two or more. · The method for calculating the hydrogen concentration J is not limited to the examples of the above embodiments. For example, a map representing the relationship between the hydrogen concentration J and the parameters indicating the operating state of the internal combustion engine 10 may be created. The map is not limited to a table or a graph, and may also be a mathematical formula. The method for calculating the hydrogen concentration J may be any method that can calculate the hydrogen concentration J based on the operating state of the internal combustion engine 10.

[0091] · The configuration of the internal combustion engine 10 is not limited to the examples of the above embodiments. For example, the number of cylinders 2 may be changed from that in the above embodiments. The fuel injection valve 17 may be changed to a type that supplies fuel to the cylinder 2 via the intake passage 3. The configuration of the supercharger 40 may be changed. For example, as the supercharger, a variable displacement type having a nozzle vane may be adopted. In this case, when changing the rotational speed of the compressor wheel to reduce the downstream pressure LP, the opening degree of the nozzle vane may be changed. Also, as the supercharger, an electric type that rotates the compressor wheel with an electric motor may be adopted. In this case, when changing the rotational speed of the compressor wheel, the rotational speed of the electric motor may be changed. Note that it is not essential for the internal combustion engine 10 to have a supercharger. Even for an internal combustion engine 10 without a supercharger, the pressure reduction process can be realized by changing the throttle opening degree or the like. The configuration of the blow-by gas treatment mechanism may be changed from the aspect of the above embodiments. The blow-by gas treatment mechanism only needs to have a communication passage connecting the crankcase 11 and the downstream passage 3A. The configuration of the communication passage is not limited to the examples of the above embodiments, and any configuration that connects the crankcase 11 and the downstream passage 3A may be used. For example, the communication passage may be configured to penetrate the cylinder block 12 and the cylinder head 18. The specific configuration in this case is as follows. An internal combustion engine 10 is provided with a through hole that opens to the crankcase 11 and vertically penetrates the cylinder block 12 and the cylinder head 18. Then, the opening of this through hole on the side opposite to the crankcase 11 is communicated with a gas storage space partitioned between the cylinder head 18 and the cylinder head cover. Then, this storage space is connected to the downstream passage 3A by a specified passage that passes outside the cylinder head cover and reaches the downstream passage 3A. Such a through hole, storage space, and specified passage may constitute the communication passage.

[0092] ·In calculating the hydrogen concentration J, the region targeted is not limited to only the crankcase 11. The hydrogen concentration J may be calculated targeting not only the crankcase 11 but also the region including the communication passage. Further, the hydrogen concentration J may be calculated targeting only the communication passage. The hydrogen concentration J may be calculated targeting only a part of the crankcase 11 or only a part of the communication passage. The region combining the entire region of the crankcase 11 and the entire region of the communication passage is referred to as the target region. The hydrogen concentration J only needs to be calculated targeting a certain specific part within the target region. In the case of the above embodiment, the entire region of the crankcase 11 corresponds to the specific part.

[0093] ·The overall configuration of the vehicle 90 is not limited to the example of the above embodiment. For example, the vehicle may have two motor generators in addition to the internal combustion engine 10 as a drive source. Even in this case, if either of the two motor generators is used as an axle motor capable of applying torque to the axle, the following becomes possible. That is, when the pressure reduction process is executed, by increasing the torque input from the axle motor to the axle, a decrease in the torque input to the axle can be suppressed. Also, as described above, in a configuration having two motor generators as the drive source of the vehicle, if either of the two motor generators is used as an engine motor capable of applying torque to the internal combustion engine 10, the following becomes possible. That is, the crankshaft 7 can be rotated by the torque of the engine motor while stopping the combustion of fuel in the internal combustion engine 10. Thereby, similar to the first reduction process of the above embodiment, hydrogen gas can be discharged from the crankcase 11. When the vehicle has two motor generators as the drive source, the axle motor and the engine motor may be the same or separate.

[0094] · The vehicle may have only the internal combustion engine 10 as the drive source and may not have a motor generator. Even in such a vehicle, when the hydrogen concentration J becomes high, for example, by reducing the throttle opening by a predetermined specified opening, the downstream pressure LP can be reduced, and hydrogen gas can be discharged from the crankcase 11. The above-mentioned specified opening may be determined in advance by experiments or simulations, for example, as the amount of reduction in the throttle opening necessary to make the downstream pressure LP smaller than the pressure RP in the crankcase 11.

[0095] (Supplementary Notes) The above-described embodiments and modification examples include the configurations described below. [Supplementary Note 1] A vehicle-mounted control device for a vehicle equipped with an internal combustion engine that has a communication passage connecting from the crankcase to the downstream passage, which is the portion downstream of the throttle valve in the intake passage, and uses hydrogen as fuel, and calculates the hydrogen concentration in a specific portion of the target area combining the crankcase and the communication passage based on the operating state of the internal combustion engine, and a pressure reduction process for reducing the pressure in the downstream passage when a condition including that the hydrogen concentration is equal to or higher than a predetermined determination value is satisfied.

[0096] [Supplementary Note 2] The vehicle control device according to [Supplementary Note 1], wherein the pressure reduction process is a process of reducing the opening degree of the throttle valve compared to the time when the condition is satisfied. [Supplementary Note 3] The internal combustion engine has a compressor wheel for supercharging the intake air upstream of the throttle valve in the intake passage, and the pressure reduction process is a process of reducing the rotational speed of the compressor wheel compared to the time when the condition is satisfied, as described in [Supplementary Note 1].

[0097] [Supplementary Note 4] The vehicle control device according to [Supplementary Note 3], wherein the pressure reduction process is a process of stopping the supercharging of the intake air by the compressor wheel and further reducing the opening degree of the throttle valve to be smaller than fully open.

[0098] [Appendix 5] The vehicle has a motor capable of applying torque to an axle for transmitting driving force to wheels, and when executing the pressure reduction process, increases the torque input from the motor to the axle compared to the time when the condition is satisfied. The control device for a vehicle according to any one of [Appendix 1] to [Appendix 4].

[0099] [Appendix 6] The vehicle has a motor capable of applying torque to the crankshaft of the internal combustion engine, and the pressure reduction process rotates the crankshaft by the torque of the motor and reduces the opening degree of the throttle valve compared to the time when the condition is satisfied. The control device for a vehicle according to [Appendix 1].

[0100] [Appendix 7] It has a storage device and an execution device. The storage device stores in advance mapping data that defines a mapping that outputs a variable indicating the hydrogen concentration as an output variable when a plurality of input variables are input, and the mapping is learned by machine learning. The mapping includes, as one of the plurality of input variables, a variable indicating the pressure of the downstream passage. The execution device executes, as the hydrogen concentration calculation process, an acquisition process of acquiring the values of the input variables and a calculation process of calculating the value of the output variable by inputting the values of the input variables acquired by the acquisition process into the mapping. The control device for a vehicle according to any one of [Appendix 1] to [Appendix 6].

Explanation of Reference Numerals

[0101] 3... Intake passage 3A... Downstream passage 7... Crankshaft 10... Internal combustion engine 11... Crankcase 29... Throttle valve 41... Compressor wheel 51... First communication passage 72... Driving wheels 73... Axle 82... Motor generator 90... Vehicle 100... Control device 111... CPU 112…ROM 113…Memory device

Claims

1. A vehicle equipped with an internal combustion engine that has a communication passage connecting from a crankcase to a downstream passage which is a portion downstream of a throttle valve in an intake passage, and uses hydrogen as fuel is a control target, a hydrogen concentration calculation process for calculating a hydrogen concentration in a specific portion of a target area combining the crankcase and the communication passage based on an operating state of the internal combustion engine, a pressure reduction process for reducing a pressure in the downstream passage when a condition including that the hydrogen concentration is equal to or more than a predetermined determination value is satisfied, compared with a time point when the condition is satisfied, is executed, wherein the pressure reduction process is a process of reducing an opening degree of the throttle valve compared with a time point when the condition is satisfied A control device for a vehicle.

2. A vehicle equipped with an internal combustion engine that has a communication passage connecting from a crankcase to a downstream passage which is a portion downstream of a throttle valve in an intake passage, and a compressor wheel that is located upstream of the throttle valve in the intake passage and supercharges intake air, and uses hydrogen as fuel is a control target, a hydrogen concentration calculation process for calculating a hydrogen concentration in a specific portion of a target area combining the crankcase and the communication passage based on an operating state of the internal combustion engine, a pressure reduction process for reducing a pressure in the downstream passage when a condition including that the hydrogen concentration is equal to or more than a predetermined determination value is satisfied, compared with a time point when the condition is satisfied, is executed, wherein the pressure reduction process is a process of reducing a rotational speed of the compressor wheel compared with a time point when the condition is satisfied A control device for a vehicle.

3. The pressure reduction process is a process of stopping supercharging of intake air by the compressor wheel and further reducing an opening degree of the throttle valve to be smaller than fully open The control device for a vehicle according to Claim 2.

4. A vehicle equipped with an internal combustion engine that has a communication passage connecting from a crankcase to a downstream passage which is a portion downstream of a throttle valve in an intake passage, and uses hydrogen as fuel, and a motor capable of applying torque to an axle for transmitting driving force to wheels is a control target, a hydrogen concentration calculation process for calculating a hydrogen concentration in a specific portion of a target area combining the crankcase and the communication passage based on an operating state of the internal combustion engine, When a condition including that the hydrogen concentration is equal to or higher than a predetermined determination value is satisfied, a pressure reduction process for reducing the pressure in the downstream passage compared to the time point when the condition is satisfied, is executed, When executing the pressure reduction process, the torque input from the motor to the axle is increased compared to the time point when the condition is satisfied A vehicle control device.

5. A vehicle equipped with an internal combustion engine that has a communication passage connecting from the crankcase to a downstream passage, which is a portion downstream of the throttle valve in the intake passage, and uses hydrogen as fuel, and a motor capable of applying torque to the crankshaft of the internal combustion engine is a control target, A hydrogen concentration calculation process for calculating the hydrogen concentration in a specific portion of a target region combining the crankcase and the communication passage based on the operating state of the internal combustion engine, When a condition including that the hydrogen concentration is equal to or higher than a predetermined determination value is satisfied, a pressure reduction process for reducing the pressure in the downstream passage compared to the time point when the condition is satisfied, is executed, The pressure reduction process is a process of rotating the crankshaft by the torque of the motor and reducing the opening degree of the throttle valve compared to the time point when the condition is satisfied A vehicle control device.

6. A vehicle equipped with an internal combustion engine that has a communication passage connecting from the crankcase to a downstream passage, which is a portion downstream of the throttle valve in the intake passage, and uses hydrogen as fuel is a control target, It has a storage device and an execution device, The storage device stores in advance mapping data that defines a mapping that outputs, as an output variable, a variable indicating the hydrogen concentration in a specific portion of a target region combining the crankcase and the communication passage when a plurality of input variables are input, and the mapping is learned by machine learning, The mapping includes, as one of the plurality of input variables, a variable indicating the pressure in the downstream passage, The execution device, An acquisition process for acquiring the values of the input variables, A calculation process for calculating the value of the output variable by inputting the values of the input variables acquired by the acquisition process into the mapping, When a condition including that the hydrogen concentration is equal to or higher than a predetermined determination value is satisfied, a pressure reduction process for reducing the pressure in the downstream passage compared to the time point when the condition is satisfied, is executed A vehicle control device.

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