Control device of hybrid vehicle

Abstract

To provide a control device of a hybrid vehicle which can suppress rust caused by moisture generated by combustion.SOLUTION: A control device of a hybrid vehicle, in which a processor 152 of an ECU 150 includes an internal combustion engine 10 having an oil jet 31 for supplying oil to the periphery of a piston 15, and an MG 112 for vehicle driving, includes: a fuel injection control part 152b for controlling fuel injection to the internal combustion engine 10 and stopping fuel injection before the internal combustion engine 10 is stopped; a first motoring operation part 152c1 for reducing an intake air quantity into a cylinder in a state in which the fuel injection is stopped before the internal combustion engine 10 is stopped, rotating a crank shaft 18 of the internal combustion engine 10 by drive force of the MG 112 and performing first motoring operation; and an engine stop part 152d for stopping the internal combustion engine 10 after the first motoring operation.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a control device for a hybrid vehicle. [Background technology]

[0002] Conventionally, in hybrid vehicles, it is known that by motoring the engine for a specified period during which the engine is intermittently stopped when EGR begins after warming up, condensed water flowing in from the EGR system is evaporated and discharged, thereby suppressing the adhesion of condensed water, which is one of the causes of deposit formation in fuel injection valves (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-043156 A Summary of the Invention [Problem to be solved by the invention]

[0004] In an internal combustion engine, the burnt gas generated by combustion contains moisture, and as the burnt gas passes through the gap between the piston and the cylinder, it is cooled and condenses. Therefore, when the vehicle system is stopped, the condensed water may adhere to components of the internal combustion engine, such as the cylinder liner, piston ring, piston wear ring, and combustion chamber inner wall, which are made of iron, and cause rust. If rust occurs on these components, there are concerns about an increase in blow-by gas and a deterioration in fuel efficiency due to increased friction. In particular, in an internal combustion engine that uses hydrogen as fuel, the burnt gas generated when hydrogen is burned contains a lot of moisture, so these rust problems may occur more significantly.

[0005] However, the technology described in Patent Document 1 assumes the discharge of condensed water when the vehicle drive system is in operation, and does not take into consideration the effects of moisture while the vehicle drive system is stopped, such as when the vehicle is parked. When the vehicle is stopped, the burnt gas in the cylinder cools and condenses inside the cylinder, which causes rust to form on the iron members, but the technology described in the above Patent Document makes it difficult to prevent rust from occurring due to residual moisture in the cylinder when the vehicle is stopped.

[0006] In view of the above problems, an object of the present disclosure is to provide a control device for a hybrid vehicle that is capable of suppressing rust caused by moisture generated by combustion. [Means for solving the problem]

[0007] The gist of the present disclosure is as follows.

[0008] (1) A control device for a hybrid vehicle including an internal combustion engine having an oil supply unit that supplies oil to a periphery of a piston, and a motor for driving the vehicle, comprising: a fuel injection control unit that controls fuel injection into the internal combustion engine and stops fuel injection before the internal combustion engine is stopped; a first motoring operation unit that reduces an amount of intake air into a cylinder in a state where fuel injection is stopped before the internal combustion engine is stopped, and rotates a crankshaft of the internal combustion engine with a driving force of the motor to perform a first motoring operation; an engine stopping unit that stops the internal combustion engine after the first motoring operation; A control device for a hybrid vehicle comprising:

[0009] (2) a second motoring operation unit that, when the first motoring operation is performed to stop the internal combustion engine, increases the amount of intake air into the cylinders with fuel injection stopped and rotates the crankshaft with the driving force of the motor to perform a second motoring operation when the internal combustion engine is next started, The control device for a hybrid vehicle according to (1) above, wherein the fuel injection control unit starts fuel injection after the second motoring operation.

[0010] (3) The control device for a hybrid vehicle according to (1) or (2) above, wherein the first motoring operation unit performs the first motoring operation by fully closing a throttle valve.

[0011] (4) The control device for a hybrid vehicle according to (2) above, wherein the second motoring operation unit fully opens a throttle valve to perform the second motoring operation.

[0012] (5) A SOC determination unit that determines a SOC of a battery; The control device for a hybrid vehicle according to any one of (1) to (4) above, wherein the first motoring operation unit does not perform the first motoring operation when a battery SOC is less than a predetermined value.

[0013] (6) A SOC determination unit is provided to determine a SOC of a battery; The control device for a hybrid vehicle according to (2) or (4) above, wherein the second motoring operation unit does not perform the second motoring operation when a battery SOC is less than a predetermined value.

[0014] (7) The control device for a hybrid vehicle according to any one of (1) to (6) above, wherein the internal combustion engine uses hydrogen as fuel. Effect of the Invention

[0015] According to the present disclosure, a control device for a hybrid vehicle is provided that is capable of suppressing rust caused by moisture generated by combustion. [Brief description of the drawings]

[0016] [Figure 1] 1 is a diagram illustrating a schematic configuration of a vehicle according to an embodiment. [Diagram 2]FIG. 2 is a schematic diagram showing the configuration of a system including an internal combustion engine and a MG. [Diagram 3] FIG. 2 is a schematic diagram showing functional blocks of a processor of the ECU. [Figure 4] 4 is a flowchart showing a process performed by a processor of the ECU at each predetermined control period. [Diagram 5] 4 is a flowchart showing a process performed by a processor of the ECU at each predetermined control period. [Figure 6] 4 is a flowchart showing a process performed by a processor of the ECU at each predetermined control period. [Figure 7] 4 is a flowchart showing a process performed by a processor of the ECU at each predetermined control period. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, some embodiments of the present invention will be described with reference to the drawings. However, these descriptions are intended to merely exemplify preferred embodiments of the present invention, and are not intended to limit the present invention to such specific embodiments. In the following description, similar components are given the same reference numerals.

[0018] Fig. 1 is a diagram that shows a schematic configuration of a vehicle 200 according to one embodiment. In Fig. 1, the left side shows the front of the vehicle 200, and the right side shows the rear of the vehicle 200. As shown in Fig. 1, the vehicle 200 has an internal combustion engine 10, a motor generator (MG) 112, and a power split mechanism 116. In addition, the vehicle 200 includes a power control unit (PCU) 118 that is electrically connected to the MG 112, and a battery 120 that is electrically connected to the PCU 118.

[0019] In this embodiment, the internal combustion engine 10 is exemplified as a prime mover that uses hydrogen as fuel, burns the hydrogen inside the engine, and converts the thermal energy of the combustion gas into mechanical energy. Meanwhile, the fuel for the internal combustion engine 10 is not limited to hydrogen, and any fuel that generates moisture when burned can provide the rust prevention effect according to this embodiment, and the occurrence of rust in iron parts can be suppressed. Therefore, biofuel, ethanol-based fuel, gasoline, diesel, etc. can be used as the fuel for the internal combustion engine 10.

[0020] The internal combustion engine 10 is connected to a power split mechanism 116, and the output of the internal combustion engine 10 is used to drive the vehicle 200 and to generate electricity in the MG 112.

[0021] The MG 112 functions as an electric motor and a generator. The MG 112 is connected to the power split mechanism 116, and is used to drive the vehicle 200 and to perform regeneration when braking the vehicle 200. The MG 112 is also capable of driving the internal combustion engine 10 to perform motoring operation. Note that, in this embodiment, the MG 112 having a power generating function is used as the motor that drives the vehicle 200, but a motor without a power generating function may also be used.

[0022] The PCU 118 is connected between the battery 120 and the MG 112, and controls the power supplied to the MG 112. The PCU 118 has components such as an inverter that drives a motor, a boost converter that controls voltage, and a DC-DC converter that steps down a high voltage. The battery 120 is connected to the PCU 118 and the MG 112, and supplies power to the MG 112 for driving the vehicle 200.

[0023] As described above, the vehicle 200 is configured as a hybrid vehicle equipped with the internal combustion engine 10 fueled by hydrogen and the MG 112. The vehicle 200 may be any type of vehicle as long as it is equipped with the internal combustion engine 10 and the MG (or motor) 112 and the internal combustion engine 10 can be driven by the MG 112. Therefore, for example, the vehicle 200 may be configured such that the internal combustion engine 10 is used only for power generation and only the motor drives the vehicle 200. Also, for example, the vehicle 200 may be configured to have two MGs, one used mainly for driving the vehicle 200 and the other used mainly for power generation.

[0024] Fig. 2 is a schematic diagram showing the configuration of a system 100 including an internal combustion engine 10 and an MG 112. As shown in Fig. 2, the internal combustion engine 10 includes a cylinder block 11, a cylinder head 12, a head cover 13, and an oil pan 14. A piston 15 is provided in a cylinder 16 of the cylinder block 11 so as to be capable of reciprocating. The piston 15 is provided with a plurality of piston rings. A combustion chamber 17 is formed by a space surrounded by a wall surface of the cylinder 16, a crown surface of the piston 15, and the cylinder head 12. The head cover 13 is provided with a filler cap for injecting oil, and the like.

[0025] An intake camshaft (not shown) that drives the intake valve to open and close, and an exhaust camshaft (not shown) that drives the exhaust valve to open and close are rotatably provided in the cylinder head 12. In addition, the cylinder head 12 is also provided with a fuel injection valve (not shown).

[0026] A crankcase 19 that rotatably supports a crankshaft 18 is provided below the cylinder block 11. An oil pan 14 that stores lubricating oil is attached below the crankcase 19.

[0027] An intake manifold 29 equipped with a surge tank 60 is connected to the cylinder head 12, and an intake pipe 20 in which various devices are installed is connected upstream of the surge tank 60. The intake pipe 20, the surge tank 60, and the intake manifold 29 form an intake passage of the internal combustion engine 10. In addition, an exhaust manifold 30 is connected to the cylinder head 12. An exhaust pipe (not shown) equipped with an exhaust purification catalyst is connected downstream of the exhaust manifold 30.

[0028] In the intake pipe 20, from upstream, there are installed an air cleaner 21, an air flow meter 91, a compressor 24C of a turbocharger 24 that is driven by exhaust gas from the combustion chamber 17, an intercooler 27, a pressure sensor 93, and an electric throttle valve 28.

[0029] The air cleaner 21 filters the intake air taken into the intake pipe 20, and the turbocharger 24 compresses (supercharges) the air taken into the intake pipe 20. The intercooler 27 cools the air after passing through the compressor 24C, and the opening of the throttle valve 28 is adjusted to adjust the amount of intake air.

[0030] The internal combustion engine 10 includes an oil jet 31. The oil jet 31 is one aspect of an oil supply unit that supplies oil to the periphery of the piston 15. The oil jet 31 is attached to the lower end of the cylinder block 11. The oil jet 31 is connected to a pump (not shown) that is driven by the rotation of the internal combustion engine 10. When the pump is driven, oil flows into the oil jet 31. The oil that flows into the oil jet 31 is sprayed from a nozzle 31a of the oil jet 31 toward the surface of the piston 15 on the bottom dead center side. The oil supply unit may be configured in such a way that the crankshaft 18 scoops up the oil in the oil pan 14.

[0031] The ECU 150 is one aspect of a control device for a hybrid vehicle, and controls the system 100 including the internal combustion engine 10 and the MG 112, and performs various controls of the system 100 by operating various target devices such as the throttle valve 28, the fuel injection valve, and the MG 112. The ECU 150 has a processor 152, a memory 154, and a communication interface 156. The processor 152 has one or more CPUs (Central Processing Units) and their peripheral circuits. The processor 152 may further have other arithmetic circuits such as a logic arithmetic unit, a numerical arithmetic unit, or a graphic processing unit. The memory 154 has, for example, a volatile semiconductor memory and a non-volatile semiconductor memory, and stores data related to the processing according to this embodiment as necessary. The communication interface 156 has an interface circuit for connecting the ECU 150 to an in-vehicle network.

[0032] When carrying out various controls of the internal combustion engine 10, the ECU 150 refers to the intake air amount detected by the air flow meter 91, the engine rotation speed calculated from the output signal of the crank angle sensor 92, and the terminal current and terminal voltage of the battery 120 detected by the battery sensor 96. When carrying out various controls of the internal combustion engine 10, the ECU 150 also refers to the intake air pressure detected by the pressure sensor 93, the output signal of the accelerator opening sensor 94 that detects the amount of operation of the accelerator pedal (accelerator opening), the vehicle speed of the vehicle 200 detected by the vehicle speed sensor 95, etc. When carrying out various controls of the MG 112, the ECU 150 also refers to the terminal current and terminal voltage of the battery 120 detected by the battery sensor 96, etc.

[0033] The throttle valve 28, the ignition switch 97, the fuel injector or MG 112, and the various sensors of the system 100 are connected to the ECU 150 via an in-vehicle network that complies with a standard such as a Controller Area Network (CAN).

[0034] The internal combustion engine 10 that burns hydrogen mainly produces water when hydrogen is burned. Therefore, moisture is present inside the cylinder 16. This causes moisture to adhere to the cylinder liner, piston rings, piston wear rings, and the like, which are made of iron, and there is a possibility that these components will rust while the system 100 is stopped. As a result, as described above, there are concerns that blow-by gas will increase and fuel efficiency will worsen due to increased friction.

[0035] In this embodiment, when the driver of the vehicle turns off the ignition switch 97 to stop the system 100, fuel injection is cut for a predetermined time before the system is stopped, and the crankshaft 18 is rotated by the MG 112 with the throttle valve 28 fully closed. As a result, moisture in the cylinder is scavenged and discharged from the exhaust manifold 30 through the exhaust pipe. In addition, by fully closing the throttle valve 28, negative pressure is generated in the combustion chamber 17, and oil flows into the combustion chamber 17 side from the gap between the cylinder 16 and the piston 15, and the oil is supplied to the piston 15, the cylinder 16, or the combustion chamber 17 and the parts around it, and these parts are covered with a film of oil. Therefore, rust caused by moisture generated by the combustion of hydrogen is suppressed, and rust prevention can be performed. In this specification, rotating the crankshaft 18 by the MG 112 is called motoring.

[0036] On the other hand, if the above-mentioned rust prevention is performed before the system is stopped, the next time the system 100 is started and the internal combustion engine 10 is operated, the oil supplied to the piston 15, the cylinder 16, the combustion chamber 17, and the parts around them will be burned, generating particulate matter (PM: Particulate Matter) derived from the oil, and the number of particulate matter (PN: Particulate Number) emitted from the internal combustion engine 10 may increase. For this reason, when the system is started, fuel injection is stopped and motoring is performed for a predetermined time with the throttle valve 28 fully open. This allows air to pass through the gap between the cylinder 16 and the piston 15 and flow into the crankcase 19. Therefore, the oil supplied to the piston 15, the cylinder 16, the combustion chamber 17, and the parts around them will be returned to the crankcase 19 together with the air passing through the gap between the cylinder 16 and the piston 15.

[0037] FIG. 3 is a schematic diagram showing functional blocks of the processor 152 of the ECU 150 for realizing the above-mentioned processing. The processor 152 of the ECU 150 has a system requirement determination unit 152a, a fuel injection control unit 152b, a motoring operation unit 152c, an engine stop unit 152d, and an SOC determination unit 152e. Each of these units of the processor 152 is a functional module realized by, for example, a computer program that runs on the processor 152. That is, the functional blocks of the processor 152 are configured by the processor 152 and a program (software) for making the processor 152 function. The program may be recorded in the memory 154 of the ECU 150 or in a recording medium connected from the outside. Alternatively, each of these units of the processor 152 may be a dedicated arithmetic circuit provided in the processor 152.

[0038] The system request determination unit 152a of the processor 152 determines whether a request to stop or start the system 100 has been issued. For example, when the operational state of the ignition switch 97 is turned off, the system request determination unit 152a determines that a request to stop the system 100 has been issued. Also, when the operational state of the ignition switch 97 is turned on, the system request determination unit 152a determines that a request to start the system 100 has been issued.

[0039] The fuel injection control unit 152b of the processor 152 stops fuel injection before stopping the internal combustion engine 10. Furthermore, when the internal combustion engine 10 is stopped by performing a first motoring operation described below, the fuel injection control unit 152b starts fuel injection after a second motoring operation described below when the internal combustion engine 10 is next started.

[0040] The motoring operation unit 152c of the processor 152 has a first motoring operation unit 152c1 and a second motoring operation unit 152c2. Before stopping the internal combustion engine 10, the first motoring operation unit 152c1 reduces the amount of intake air into the cylinder with fuel injection stopped, and rotates the crankshaft 18 with the driving force of the MG 112 to perform a first motoring operation (rust prevention operation). The first motoring operation unit 152c1 reduces the amount of intake air into the cylinder, for example, by fully closing the throttle valve 28.

[0041] During the first motoring operation, fuel injection is stopped, so no new moisture is generated by combustion. In addition, by performing the first motoring operation, air flows from the intake manifold 29 to the exhaust manifold 30, scavenging moisture remaining inside the combustion chamber 17 and discharging it from the exhaust pipe to the outside. Therefore, by removing the moisture, a rust prevention effect is obtained.

[0042] In addition, since the first motoring operation is performed in a state where no explosion pressure is generated in the combustion chamber 17, the oil is sucked in by the negative pressure in the cylinder during the intake stroke, and the oil flows into the combustion chamber 17 through the gap between the piston 15 and the cylinder 16, and the piston 15, the cylinder 16, the combustion chamber 17, and the parts around it are covered with a film of oil. In addition, since the amount of intake air into the cylinder is reduced at this time, the negative pressure in the cylinder is effectively generated, and the oil is reliably sucked in. As a result, the oil is distributed to these parts, and the contact of moisture with these parts is suppressed, so a more reliable rust prevention effect is obtained. Therefore, the occurrence of rust on these parts is suppressed.

[0043] The rust prevention effect by the first motoring operation can be obtained both before and after warming up the internal combustion engine 10. Furthermore, when the internal combustion engine 10 is an engine that uses hydrogen as fuel as in this embodiment, the burned gas contains a large amount of moisture, but by performing the first motoring operation, the occurrence of rust on iron members is reliably suppressed.

[0044] The first motoring operation unit 152c1 may perform the first motoring operation until the parts requiring rust prevention are covered with an oil film. For example, the first motoring operation unit 152c1 may perform the first motoring operation until the periphery of the piston ring (including the sliding surface between the piston ring and the inner wall of the cylinder 16, the land portion between the upper and lower piston rings, etc.) is covered with an oil film of a thickness sufficient to obtain a desired rust prevention effect. By performing the first motoring operation, the thickness of the oil film around the piston ring is increased compared to the case where the first motoring operation is not performed. Specifically, when the first motoring operation is not performed, the oil film thickness on the sliding surface between the piston ring and the inner wall of the cylinder 16 is about several μm, and the oil film thickness on the land portion between the upper and lower piston rings is about 10 μm, but by performing the first motoring operation, the thickness of these oil films increases by about 1.5 to 10 times. Basically, the thicker the oil film, the more effective it is in preventing rust. However, once a certain level of oil film thickness is formed, there is no significant change in the rust prevention effect even if the oil film is further increased in thickness. Therefore, the period during which the first motoring operation is performed is determined as a period during which sufficient rust prevention effect can be obtained without excessively extending the motoring time, taking into consideration the thickness of the oil film and the motoring time. The period until the periphery of the piston ring is covered with an oil film thick enough to obtain the desired rust prevention effect can be determined by experiment, but as an example, it is about 200 cycles.

[0045] In addition, the higher the rotation speed of the first motoring operation, the thicker the oil film becomes. Therefore, the higher the rotation speed of the first motoring operation, the shorter the period during which the first motoring operation is performed can be.

[0046] When the internal combustion engine 10 is stopped by performing the first motoring operation, the second motoring operation unit 152c2 increases the amount of intake air into the cylinders with fuel injection stopped when the internal combustion engine 10 is next started, and performs the second motoring operation by rotating the crankshaft 18 with the driving force of the MG 112. The second motoring operation unit 152c2 increases the amount of intake air into the cylinders, for example, by fully opening the throttle valve 28.

[0047] During the second motoring operation, the amount of intake air into the cylinder is increased, so that when the piston 15 rises during the compression stroke, the air in the combustion chamber 17 is compressed with a higher pressure inside the cylinder. This causes the air compressed to high pressure to flow into the crankcase 19 through the gap between the piston 15 and the cylinder 16. This causes the oil that covered the combustion chamber 17 and the periphery of the piston ring to be returned to the crankcase 19 together with the compressed air. Therefore, by starting fuel injection after the second motoring operation, the oil that covered the piston 15, the cylinder 16, or the combustion chamber 17 and its surrounding parts is prevented from burning and generating PM, and an increase in PN is suppressed. Therefore, the deterioration of emissions due to oil burning is reliably suppressed.

[0048] The second motoring operation is performed until the oil covering the piston 15, the cylinder 16, or the combustion chamber 17 and the parts around them is removed (or until the thickness of the oil film becomes equal to or less than a predetermined value). For example, the second motoring operation unit 152c2 may perform the second motoring operation until the oil film is removed from the piston ring (or until the thickness of the oil film becomes equal to or less than a predetermined value). The period during which the second motoring operation is performed can be determined by experiment, but may be about 200 cycles, for example.

[0049] The first motoring operation unit 152c1 does not perform the first motoring operation when the state of charge (SOC) of the battery 120 is less than a predetermined value. Similarly, the second motoring operation unit 152c2 does not perform the second motoring operation when the SOC of the battery 120 is less than a predetermined value. This suppresses power consumption due to motoring and further reduction in SOC, thereby suppressing starting problems of the internal combustion engine 10 due to lack of power.

[0050] After the first motoring operation, the engine stop unit 152d of the processor 152 stops the internal combustion engine 10. Specifically, the engine stop unit 152d stops the internal combustion engine 10 by turning off the driving force of the MG 112.

[0051] When performing motoring operation at system shutdown or startup, the SOC determination unit 152e of the processor 152 determines the SOC of the battery 120 based on the terminal current and terminal voltage of the battery 120 detected by the battery sensor 96. The SOC determination unit 152e determines whether the SOC of the battery 120 is equal to or higher than a predetermined value.

[0052] The processing performed by processor 152 of ECU 150 will be described below with reference to the flowcharts of Figures 4 to 7. Figures 4 to 7 are flowcharts showing the processing performed by processor 152 of ECU 150 at each predetermined control cycle.

[0053] 4 is a flowchart showing the process when the system is stopped. First, the system request determination unit 152a of the processor 152 determines whether or not a request to stop the system 100 has been issued (step S10). When the driver of the vehicle turns off the ignition switch 97, the system request determination unit 152a determines that a system stop request has been issued.

[0054] When it is determined in step S10 that a system stop request has been issued, the processor 152 determines whether or not the internal combustion engine 10 was operating while the system 100 was in operation (while the vehicle 200 was tripping) before the stop request was issued (step S12). On the other hand, when it is determined in step S10 that a system stop request has not been issued, the processing in this control cycle ends.

[0055] If it is determined in step S12 that the internal combustion engine 10 is operating, the fuel injection control unit 152b of the processor 152 stops fuel injection (step S13). On the other hand, if it is determined in step S12 that the internal combustion engine 10 is not operating, moisture has not been generated by the combustion of hydrogen and rust prevention is not necessary, so the processing in this control cycle ends.

[0056] Next, the first motoring operation unit 152c1 of the processor 152 fully closes the throttle valve 28 (step S14) and rotates the crankshaft 18 with the driving force of the MG 112 to perform the first motoring operation (step S16). Next, the engine stop unit 152d of the processor 152 stops the internal combustion engine 10 after the first motoring operation (step S18). After step S18, the processing in this control cycle ends.

[0057] 5 is a flowchart showing the process at the time of system startup. First, the system request determination unit 152a of the processor 152 determines whether or not a request to start the system 100 has been issued (step S20). When the driver of the vehicle turns on the ignition switch 97, the system request determination unit 152a determines that a system startup request has been issued.

[0058] When it is determined in step S20 that a system startup request has been issued, processor 152 determines whether or not the first motoring operation (rust prevention operation) was performed the previous time the system was stopped (step S22). On the other hand, when it is determined in step S20 that a system startup request has not been issued, the processing in this control cycle ends.

[0059] If it is determined in step S22 that the first motoring operation was performed when the system was previously stopped, the second motoring operation unit 152c2 of the processor 152 fully opens the throttle valve 28 (step S24) and rotates the crankshaft 18 with the driving force of the MG 112 to perform the second motoring operation (step S26). On the other hand, if it is determined in step S22 that the first motoring operation is not being performed, the processing in this control cycle ends.

[0060] Next, the fuel injection control unit 152b of the processor 152 starts fuel injection after the second motoring operation (step S28). After step S28, the processing in this control cycle ends.

[0061] 6 is a flowchart showing a process of performing the first motoring operation when the SOC of the battery 120 is equal to or greater than the predetermined value X in the process of FIG. 4. In this case, when it is determined in step S12 that the internal combustion engine 10 is operating, the SOC determination unit 152e of the processor 152 determines whether the SOC of the battery 120 is equal to or greater than the predetermined value X (step S19). If the SOC of the battery 120 is equal to or greater than the predetermined value X in step S19, the process of step S13 and subsequent steps is performed. On the other hand, if the SOC of the battery 120 is less than the predetermined value X in step S19, the process of step S13 and subsequent steps is not performed. Note that in FIG. 6, the processes other than step S19 are performed in the same manner as in FIG. 4.

[0062] 7 is a flowchart showing the process of performing the second motoring operation when the SOC of the battery 120 is equal to or greater than the predetermined value X in the process of FIG. 5. In this case, when it is determined in step S22 that the first motoring operation was performed at the time of the previous system stop, the SOC determination unit 152e of the processor 152 determines whether or not the SOC of the battery 120 is equal to or greater than the predetermined value X (step S29). If the SOC of the battery 120 is equal to or greater than the predetermined value X in step S29, the process of step S24 and subsequent steps is performed. On the other hand, if the SOC of the battery 120 is less than the predetermined value X in step S29, the process of step S24 and subsequent steps is not performed. Note that in FIG. 7, the processes other than step S29 are performed in the same manner as in FIG. 5.

[0063] As described above, according to this embodiment, before the internal combustion engine 10 is stopped, the amount of intake air into the cylinder is reduced with fuel injection stopped, and the crankshaft 18 is rotated by the driving force of the MG 112 to perform a first motoring operation. This scavenges moisture remaining inside the combustion chamber 17, and the piston 15, the cylinder 16, the combustion chamber 17, and the parts around it are covered with a film of oil due to the negative pressure generated in the intake manifold 29 and the combustion chamber 17. This prevents rust from forming on these parts.

[0064] Furthermore, if the first motoring operation is performed to stop the internal combustion engine 10, when the internal combustion engine 10 is next started, the crankshaft 18 is rotated by the driving force of the MG 112 with fuel injection stopped and the amount of intake air into the cylinder increased, and a second motoring operation is performed. This causes the oil that covered the combustion chamber 17 and the periphery of the piston ring to return to the crankcase 19, suppressing the generation of PM due to the combustion of the oil that covered the piston 15, the cylinder 16, or the combustion chamber 17 and the parts around it, and suppressing an increase in PN. [Explanation of symbols]

[0065] 10 Internal combustion engine 15 Piston 16 cylinders 17 Combustion chamber 18 Crankshaft 28 Throttle valve 31 Oil Jet 96 Battery Sensor 97 Ignition Switch 100 Systems 112 Motor generator (MG) 152 processors 152a System requirement judgment unit 152b Fuel injection control unit 152c Motoring Operation Section 152c1 First motoring operation section 152c2 Second motoring operation section 152d Engine Stop Section 152e SOC judgment section 200 vehicles

Claims

1. A control device for a hybrid vehicle having an oil supply unit that supplies oil to the periphery of a piston, an internal combustion engine that uses hydrogen as fuel, and a motor for driving the vehicle, a fuel injection control unit that controls fuel injection into the internal combustion engine and stops fuel injection before stopping the internal combustion engine; a first motoring operation unit that, before stopping the internal combustion engine, reduces the amount of intake air into a cylinder with fuel injection stopped and rotates a crankshaft of the internal combustion engine using a driving force of the motor to perform a first motoring operation; an engine stopping unit that stops the internal combustion engine after the first motoring operation; A control device for a hybrid vehicle comprising:

2. a second motoring operation unit that, when the first motoring operation is performed to stop the internal combustion engine, increases the amount of intake air into the cylinders with fuel injection stopped and rotates the crankshaft with the driving force of the motor to perform a second motoring operation when the internal combustion engine is next started, The control device for a hybrid vehicle according to claim 1 , wherein the fuel injection control unit starts fuel injection after the second motoring operation.

3. 2. The control device for a hybrid vehicle according to claim 1, wherein the first motoring operation unit performs the first motoring operation by fully closing a throttle valve.

4. 3. The control device for a hybrid vehicle according to claim 2, wherein the second motoring operation unit performs the second motoring operation by fully opening a throttle valve.

5. an SOC determination unit that determines an SOC of a battery; 5. The control device for a hybrid vehicle according to claim 1, wherein the first motoring operation unit does not perform the first motoring operation when the SOC of the battery is less than a predetermined value.

6. an SOC determination unit that determines an SOC of a battery; 5. The control device for a hybrid vehicle according to claim 2, wherein the second motoring operation unit does not perform the second motoring operation when an SOC of a battery is less than a predetermined value.

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