Control device for internal combustion engine

Abstract

Provided is a control device for an internal combustion engine, which suppresses the viscosity of oil supplied from a crank chamber to each part of the internal combustion engine from becoming too high. An internal combustion engine includes a cylinder, an intake passage, an exhaust passage, a crank chamber, a communication passage, and a control valve. In the present invention, a cylinder combusts hydrogen as fuel, an intake passage introduces intake air into the cylinder, an exhaust passage discharges exhaust gas from the cylinder, a crank chamber accommodates a crank shaft and stores oil, a communication passage introduces a part of the exhaust gas flowing through the exhaust passage into the crank chamber, and a control valve opens and closes a flow path of the communication passage. A control device for an internal combustion engine acquires an oil temperature (S11), which is the temperature of oil stored in a crank chamber; determining whether or not the oil temperature is equal to or less than a predetermined prescribed temperature (S12); when it is determined that the oil temperature is equal to or less than the predetermined temperature, the opening degree of the control valve is increased compared to a case where the oil temperature is higher than the predetermined temperature (S31).

Description

TECHNICAL FIELD

[0001] The present application relates to a control device of an internal combustion engine. BACKGROUND

[0002] The internal combustion engine of Patent Document 1 is provided with a cylinder, an intake passage, an exhaust passage, a crank chamber, and a crankshaft. The cylinder is a space in which a mixture of fuel and intake air is combusted. The intake passage introduces intake air to the cylinder. The exhaust passage discharges exhaust gas from the cylinder. The crank chamber houses the crankshaft. The crank chamber also stores oil.

[0003]

Patent Document 1

[0004] In the internal combustion engine like that of Patent Document 1, generally, the oil stored in the crank chamber is supplied to each part of the internal combustion engine. Here, when the temperature of the oil stored in the crank chamber is low, the viscosity of the oil supplied from the crank chamber to each part of the internal combustion engine can become excessively high. Note that when such high-viscosity oil is supplied to each part of the internal combustion engine, the friction of each part of the internal combustion engine sometimes becomes excessively large. MEANS FOR SOLVING THE PROBLEMS

[0005] A control device of an internal combustion engine, which is an object of the present application, is provided with a cylinder in which hydrogen gas is combusted as fuel, an intake passage that introduces intake air to the cylinder, an exhaust passage that discharges exhaust gas from the cylinder, a crank chamber that houses a crankshaft and stores oil, a communication passage that introduces a part of the exhaust gas that has passed through the exhaust passage to the crank chamber, and a control valve that opens and closes a flow path of the communication passage. The control device of the internal combustion engine executes the following processing: acquires a temperature of the oil stored in the crank chamber, that is, an oil temperature; determines whether the acquired oil temperature is lower than a predetermined prescribed temperature; and increases an opening degree of the control valve when it is determined that the oil temperature is lower than the prescribed temperature, as compared with a case where it is determined that the oil temperature is higher than the prescribed temperature. EFFECT OF THE INVENTION

[0006] According to the above-described structure, it is possible to suppress the viscosity of the oil supplied from the crank chamber to each part of the internal combustion engine from becoming excessively high. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 is a schematic configuration view of a vehicle. Figure 2 is a flowchart illustrating oil temperature adjustment control. DETAILED DESCRIPTION

[0008] <Schematic Configuration of Vehicle> Hereinafter, the present application will be described in detail in accordance with the followingFigure 1 and Figure 2 An embodiment of the present invention will be described. First, the general structure of the vehicle 100 will be described. The vertical direction in the following description is based on the vertical direction of the vehicle 100. It should be noted that an example of the vehicle 100 is a so-called passenger car.

[0009] like Figure 1 As shown, the vehicle 100 is equipped with an internal combustion engine 10. The internal combustion engine 10 is equipped with a cylinder head cover 21, a cylinder head 22, a cylinder block 23, a crankcase 24, and an oil pan 25. In addition, the internal combustion engine 10 is equipped with multiple pistons 31, multiple connecting rods 32, a crankshaft 33, an intake manifold 41, and an exhaust manifold 42.

[0010] The cylinder block 23, serving as the internal space of the cylinder block 23, includes four cylinders 23A and four upper spaces 23B. Cylinders 23A extend from the upper end of the cylinder block 23 to approximately the center. Cylinders 23A are spaces used for burning a mixture of fuel and intake air. In this embodiment, the fuel is hydrogen. Therefore, the internal combustion engine 10 is a so-called hydrogen engine. The upper spaces 23B extend from the lower end of the cylinders 23A to the lower end of the cylinder block 23. A piston 31 is located inside the cylinders 23A. The piston 31 is connected to the crankshaft 33 via a connecting rod 32. The piston 31 reciprocates within the cylinders 23A due to the combustion of the fuel-intake air mixture. Furthermore, the reciprocating motion of the piston 31 causes the crankshaft 33 to rotate. It should be noted that... Figure 1 Only one cylinder, 23A, is shown in the image.

[0011] The crankcase 24 is connected to the lower end of the cylinder block 23. The crankcase 24 has a trapezoidal frame structure. Therefore, the crankcase 24, as the internal space of the crankcase 24, has four lower spaces 24A. The lower spaces 24A extend from the upper end to the lower end of the crankcase 24. The lower spaces 24A are connected to the lower ends of the upper spaces 23B. The cylinder block 23 and the crankcase 24 clamp the crankshaft 33 between them, enabling it to rotate.

[0012] An oil pan 25 is connected to the lower end of the crankcase 24. The oil pan 25 is roughly box-shaped with a bottom. Therefore, the oil pan 25 has an oil space 25A as its internal space. The oil space 25A is a space for storing oil. In this embodiment, the upper space 23B of the cylinder block 23, the lower space 24A of the crankcase 24, and the oil space 25A of the oil pan 25 constitute the crankcase 10Z of the internal combustion engine 10. It should be noted that the crankcase 10Z houses most of the crankshaft 33.

[0013] The cylinder head 22 is connected to the upper end of the cylinder block 23. The cylinder head 22, serving as the internal space, has four intake ports 22A, four exhaust ports 22B, and four combustion recesses 22C. The combustion recesses 22C are recessed upwards from the lower surface of the cylinder head 22. The combustion recesses 22C are connected to the upper end of the cylinder 23A. It should be noted that the combustion recesses 22C, the cylinder 23A, and the piston 31 define the combustion chamber 10C.

[0014] The first end of the intake port 22A is connected to the combustion recess 22C. The second end of the intake port 22A opens on the side of the cylinder head 22. The intake pipe 41 is connected to the second end of the intake port 22A. The intake pipe 41 introduces intake air from outside the internal combustion engine 10 into the intake port 22A. The intake port 22A then introduces the intake air, after passing through the intake pipe 41, into the cylinder 23A.

[0015] The first end of the exhaust port 22B is connected to the combustion recess 22C. The second end of the exhaust port 22B opens on the side of the cylinder head 22. The exhaust pipe 42 is connected to the second end of the exhaust port 22B. The exhaust port 22B discharges exhaust gas from the cylinder 23A into the exhaust pipe 42. The exhaust pipe 42 discharges the exhaust gas that has passed through the exhaust port 22B to the outside of the internal combustion engine 10.

[0016] The cylinder head cover 21 is connected to the upper end of the cylinder head 22. The cylinder head cover 21 covers the cylinder head 22. In addition, the cylinder head cover 21 and the cylinder head 22 together define a receiving space 21A. The receiving space 21A houses valve mechanisms, etc. (not shown).

[0017] The internal combustion engine 10 includes multiple intake valves 34, multiple exhaust valves 35, multiple fuel injection valves 36, and multiple ignition devices 37. The intake valves 34 are located at the connection between the intake port 22A and the combustion chamber 22C. The intake valves 34 open and close downstream of the intake port 22A via power from a valve mechanism (not shown). The exhaust valves 35 are located at the connection between the exhaust port 22B and the combustion chamber 22C. The exhaust valves 35 open and close upstream of the exhaust port 22B via power from a valve mechanism (not shown).

[0018] The front end of fuel injection valve 36 is located midway through the intake port 22A. Fuel injection valve 36 is supplied with hydrogen stored in a fuel tank (not shown). Fuel injection valve 36 injects hydrogen as fuel into intake port 22A. As a result, hydrogen is supplied to cylinder 23A via intake port 22A and combustion chamber 22C. The front end of ignition device 37 is located in combustion chamber 22C. Ignition device 37 ignites the fuel-air mixture via spark discharge.

[0019] The internal combustion engine 10 includes a throttle valve 38, multiple water injection valves 39, an air filter 46, a turbocharger 47, and an intercooler 48. The turbocharger 47 includes a compressor impeller 47A, a connecting shaft 47B, and a turbine impeller 47C. Additionally, the turbocharger 47 includes a compressor housing 47HA, a bearing housing 47HB, a turbine housing 47HC, and a variable nozzle device 47N.

[0020] The compressor housing 47HA is located midway through the intake pipe 41. In this embodiment, the intake port 22A, the intake pipe 41, and the compressor housing 47HA constitute an intake passage 10A that introduces intake air into the cylinder 23A. The turbine housing 47HC is located midway through the exhaust pipe 42. In this embodiment, the exhaust port 22B, the exhaust pipe 42, and the turbine housing 47HC constitute an exhaust passage 10B that discharges exhaust air from the cylinder 23A. The bearing housing 47HB connects the compressor housing 47HA and the turbine housing 47HC.

[0021] The compressor impeller 47A is located inside the compressor housing 47HA. In other words, the compressor housing 47HA houses the compressor impeller 47A within its internal space. The turbine impeller 47C is located inside the turbine housing 47HC. In other words, the turbine housing 47HC houses the turbine impeller 47C within its internal space. The connecting shaft 47B is located inside the bearing housing 47HB. In other words, the bearing housing 47HB houses the connecting shaft 47B within its internal space. The first end of the connecting shaft 47B is connected to the compressor impeller 47A. Furthermore, the second end of the connecting shaft 47B is connected to the turbine impeller 47C. That is, the connecting shaft 47B connects the compressor impeller 47A and the turbine impeller 47C.

[0022] When the turbine impeller 47C rotates using the exhaust flow through the exhaust passage 10B, the compressor impeller 47A rotates together via the connecting shaft 47B. As a result, the intake air compressed by the compressor impeller 47A is supplied to the downstream side of the intake passage 10A relative to the compressor impeller 47A. In other words, the turbocharger 47 uses the exhaust flow through the exhaust passage 10B to compress the intake air flowing in the intake passage 10A and supply it to the downstream side.

[0023] The variable nozzle device 47N is located within the internal space of the turbine housing 47HC. Specifically, the variable nozzle device 47N is located near the turbine impeller 47C within the internal space of the turbine housing 47HC. The variable nozzle device 47N is annular in shape around the turbine impeller 47C. The variable nozzle device 47N adjusts the size of the exhaust flow path, i.e., the gas flow path, from the portion of the exhaust passage 10B relative to the upstream side of the turbine impeller 47C to the turbine impeller 47C. Hereinafter, the size of the aforementioned gas flow path will also be referred to as the opening of the variable nozzle device 47N. It should be noted that the turbocharger 47 equipped with the variable nozzle device 47N is sometimes also referred to as a variable capacity turbocharger, a variable nozzle turbocharger, etc.

[0024] Air filter 46 is located in the intake pipe 41, upstream of compressor impeller 47A. Air filter 46 traps foreign matter contained in the intake air flowing through intake pipe 41. Intercooler 48 is located in the intake pipe 41, downstream of compressor impeller 47A. Intercooler 48 cools the intake air compressed by compressor impeller 47A. Throttle valve 38 is located in the intake pipe 41, downstream of intercooler 48. Throttle valve 38 adjusts the amount of intake air flowing through intake pipe 41.

[0025] The front end of the water injection valve 39 is located midway through the air intake 22A. The water injection valve 39 is supplied with water stored in a water tank (not shown). The water injection valve 39 injects water into the air intake 22A. When the injected water vaporizes, the air intake 22A is cooled, thereby cooling the intake air introduced from the air intake 22A into the cylinder 23A.

[0026] like Figure 1 As shown, the internal combustion engine 10 includes a filter 81, a suction pipe 82, and an oil pump 83. In this embodiment, the oil pump 83 is mounted in the crankcase 24. The oil pump 83 is a so-called mechanical pump that operates using power from the crankshaft 33. The first end of the suction pipe 82 is connected to the oil pump 83. A portion including the second end of the suction pipe 82 is located in the crankcase 10Z. The portion including the second end of the suction pipe 82 extends generally downward. The second end of the suction pipe 82 is connected to the filter 81. The filter 81 has the function of removing foreign matter contained in the oil. The lower end of the filter 81 is separated from the bottom surface of the oil pan 25. The filter 81 is located inside the oil stored in the crankcase 10Z. When the oil pump 83 operates, the oil in the crankcase 10Z is drawn from the filter 81. Furthermore, the oil drawn from the filter 81 is supplied to various parts of the internal combustion engine 10 via the suction pipe 82 and the oil pump 83.

[0027] like Figure 1As shown, the internal combustion engine 10 includes a first inlet pipe 61, a second inlet pipe 62, and a separator 63. The separator 63 is located inside the housing space 21A. The separator 63 traps engine oil contained in the gas flowing inside it. The first end of the first inlet pipe 61 is connected to the separator 63. The second end of the first inlet pipe 61 is connected to the portion of the intake pipe 41 that is downstream of the compressor impeller 47A and upstream of the intercooler 48. The first end of the second inlet pipe 62 is connected to the separator 63. The second end of the second inlet pipe 62 is connected to the crankshaft housing 10Z.

[0028] In this embodiment, the space divided by the first inlet pipe 61, the second inlet pipe 62 and the separator 63 functions as an inlet passage 60Z that guides a portion of the intake air flowing in the intake passage 10A into the crankshaft chamber 10Z.

[0029] like Figure 1 As shown, the internal combustion engine 10 includes a first discharge pipe 71, a second discharge pipe 72, and a separator 73. The separator 73 is located inside the housing space 21A. The separator 73 traps engine oil contained in the gas flowing inside it. A first end of the first discharge pipe 71 is connected to the separator 73. A second end of the first discharge pipe 71 is connected to the crankshaft housing 10Z. A first end of the second discharge pipe 72 is connected to the separator 73. A second end of the second discharge pipe 72 is connected to the portion of the intake pipe 41 upstream of the compressor impeller 47A and downstream of the air filter 46.

[0030] In this embodiment, the space divided by the first discharge pipe 71, the second discharge pipe 72 and the separator 73 functions as an discharge passage 70Z for discharging the gas present in the crankshaft chamber 10Z to the intake passage 10A.

[0031] When the internal combustion engine 10 is operating, in response to the flow of exhaust gas through the exhaust passage 10B, the compressor impeller 47A of the turbocharger 47 compresses the intake air flowing through the intake passage 10A and supplies it downstream. Therefore, the pressure in the portion of the intake passage 10A downstream of the compressor impeller 47A is higher than the pressure in the portion of the intake passage 10A upstream of the compressor impeller 47A. Furthermore, a portion of the intake air flowing through the intake passage 10A is introduced into the crankshaft chamber 10Z via the space defined by the first inlet pipe 61, the separator 63, and the second inlet pipe 62, namely the inlet passage 60Z. Additionally, as described above, when intake air is introduced into the crankshaft chamber 10Z via the inlet passage 60Z, the pressure in the crankshaft chamber 10Z increases accordingly. Therefore, the gas present in the crankshaft chamber 10Z is discharged into the portion of the intake passage 10A upstream of the compressor impeller 47A via the space defined by the first outlet pipe 71, the separator 73, and the second outlet pipe 72, namely the outlet passage 70Z.

[0032] like Figure 1 As shown, the internal combustion engine 10 includes a first connecting passage 51A, a first control valve 51V, a second connecting passage 52A, and a second control valve 52V. The first end of the first connecting passage 51A is connected to the internal space of the connecting shaft 47B in the bearing housing 47HB. The second end of the first connecting passage 51A is connected to the crankshaft chamber 10Z. The first control valve 51V is located midway through the first connecting passage 51A. The first control valve 51V opens and closes the flow path of the first connecting passage 51A.

[0033] The first end of the second connecting passage 52A is connected to the upstream portion of the exhaust pipe 42 relative to the turbine impeller 47C. In other words, the first end of the second connecting passage 52A is connected to the upstream portion of the exhaust passage 10B relative to the turbine impeller 47C. The second end of the second connecting passage 52A is connected to the crankshaft chamber 10Z. The second control valve 52V is located midway through the second connecting passage 52A. The second control valve 52V opens and closes the flow path of the second connecting passage 52A.

[0034] In this embodiment, the first connecting passage 51A and the second connecting passage 52A are examples of connecting passages that introduce a portion of the exhaust gas after it has flowed through the exhaust passage 10B into the crankshaft chamber 10Z. Furthermore, the first control valve 51V and the second control valve 52V are examples of control valves that open and close the flow paths of the connecting passages.

[0035] like Figure 1 As shown, the internal combustion engine 10 includes an accelerator operation quantity sensor 86, a vehicle speed sensor 87, a crankshaft angle sensor 88, and an oil temperature sensor 89. The accelerator operation quantity sensor 86 detects the amount of accelerator pedal operation by the driver of the vehicle 100, i.e., the accelerator operation quantity ACC. The vehicle speed sensor 87 detects the speed of the vehicle 100, i.e., the vehicle speed SP. The crankshaft angle sensor 88 detects the angular position of the crankshaft 33, i.e., the crankshaft angle SC. The oil temperature sensor 89 detects the temperature of the oil stored in the crankshaft chamber 10Z, i.e., the oil temperature TA. In this embodiment, the oil temperature sensor 89 is mounted on the oil pan 25.

[0036] like Figure 1 As shown, the vehicle 100 is equipped with a control device 90. The control device 90 obtains various information from the accelerator operation quantity sensor 86, the vehicle speed sensor 87, the crankshaft angle sensor 88, and the oil temperature sensor 89.

[0037] The control device 90 includes an execution device 91 and a storage device 92. An example of the execution device 91 is a CPU. The storage device 92 includes a read-only ROM, a read-and-write volatile RAM, and a read-and-write non-volatile memory. The storage device 92 pre-stores various programs and various data. Specifically, as one of the various programs, the storage device 92 pre-stores a control program 92A. The execution device 91 performs various processes described later by executing the control program 92A stored in the storage device 92.

[0038] The actuator 91 of the control device 90 calculates the required driving force for the vehicle 100 to move, i.e., the vehicle's required driving force, based on the accelerator operation value ACC and the vehicle speed SP. Furthermore, the actuator 91 calculates the rotational speed of the crankshaft 33, i.e., the internal combustion engine speed NE, based on the crankshaft angle SC. And, the actuator 91 controls the internal combustion engine 10 based on the vehicle's required driving force and the internal combustion engine speed NE. Specifically, the actuator 91 controls the fuel injection valve 36, ignition device 37, throttle valve 38, water injection valve 39, turbocharger 47, etc., by outputting control signals to the internal combustion engine 10. In addition, the actuator 91 can control the first control valve 51V, the second control valve 52V, etc., by outputting control signals to the internal combustion engine 10.

[0039] <Oil Temperature Adjustment Control> Next, refer to Figure 2 This describes the oil temperature adjustment control performed by the control device 90. This oil temperature adjustment control is used to adjust the oil temperature TA in the crankshaft chamber 10Z. In this embodiment, the actuator 91 of the control device 90 initiates the oil temperature adjustment control according to each predetermined control cycle, provided that the internal combustion engine 10 is operating.

[0040] like Figure 2 As shown, when the actuator 91 of the control device 90 starts the oil temperature adjustment control, it executes step S11. In step S11, the actuator 91 obtains the oil temperature TA at the start time of this oil temperature adjustment control. After step S11, the actuator 91 proceeds to step S12.

[0041] In step S12, the actuator 91 determines whether the oil temperature TA obtained in step S11 is higher than a predetermined specified temperature TZ. In this embodiment, the specified temperature TZ is a threshold value for the oil temperature TA used to determine whether it is necessary to reduce the viscosity of the oil stored in the crankshaft chamber 10Z. An example of the specified temperature TZ is approximately 80°C. In step S12, when the actuator 91 determines that the oil temperature TA is higher than the specified temperature TZ (S12: Yes), the actuator 91 proceeds the process to step S21.

[0042] In step S21, the actuator 91 controls the first control valve 51V to a fully closed state by outputting a control signal to the first control valve 51V. Furthermore, the actuator 91 controls the second control valve 52V to a fully closed state by outputting a control signal to the second control valve 52V. After step S21, the actuator 91 proceeds to step S22.

[0043] In step S22, the actuator 91 controls the variable nozzle device 47N based on a base opening degree corresponding to the operating state of the internal combustion engine 10. For example, the actuator 91 calculates the base opening degree for the variable nozzle device 47N by associating the vehicle's required driving force and the internal combustion engine speed NE with a predetermined control mapping. Furthermore, the actuator 91 controls the variable nozzle device 47N by outputting a control signal corresponding to the calculated base opening degree to the variable nozzle device 47N. After step S22, the actuator 91 terminates the current oil temperature adjustment control.

[0044] On the other hand, in step S12 above, when the actuator 91 determines that the oil temperature TA is below the specified temperature TZ (S12: No), the actuator 91 will proceed to step S31.

[0045] In step S31, the actuator 91 controls the first control valve 51V to be fully open by outputting a control signal to the first control valve 51V. In other words, when the oil temperature TA is determined to be below the specified temperature TZ, the actuator 91 increases the opening of the first control valve 51V compared to the case where the oil temperature TA is determined to be above the specified temperature TZ. Furthermore, the actuator 91 controls the second control valve 52V to be fully open by outputting a control signal to the second control valve 52V. In other words, when the oil temperature TA is determined to be below the specified temperature TZ, the actuator 91 increases the opening of the second control valve 52V compared to the case where the oil temperature TA is determined to be above the specified temperature TZ. After step S31, the actuator 91 proceeds to step S32.

[0046] In step S32, the actuator 91 controls the variable nozzle device 47N based on a corrected opening after adjusting the base opening. For example, the actuator 91 calculates the base opening for the variable nozzle device 47N by associating the vehicle's required driving force and the internal combustion engine speed NE with a predetermined control mapping. Furthermore, the actuator 91 calculates the corrected opening as a value that is a predetermined fixed value smaller than the base opening. The actuator 91 then controls the variable nozzle device 47N by outputting a control signal corresponding to the calculated corrected opening to the variable nozzle device 47N. As mentioned earlier, the opening of the variable nozzle device 47N corresponds to the size of the gas flow path, i.e., the flow path of the exhaust gas from the portion of the exhaust passage 10B upstream of the turbine impeller 47C to the turbine impeller 47C. Therefore, when it is determined that the oil temperature TA is below a specified temperature TZ, compared to when it is determined that the oil temperature TA is above the specified temperature TZ, the actuator 91 reduces the aforementioned gas flow path using the variable nozzle device 47N. After step S32, the actuator 91 ends the current oil temperature adjustment control.

[0047] <The function of this implementation method> like Figure 2 As shown, when the internal combustion engine 10 is operating, the actuator 91 of the control device 90 performs oil temperature adjustment control. Here, in step S12, when it is determined that the oil temperature TA is higher than a predetermined specified temperature TZ, the actuator 91 proceeds to step S21. In step S21, the actuator 91 controls the first control valve 51V to a fully closed state by outputting a control signal to the first control valve 51V. Furthermore, the actuator 91 controls the second control valve 52V to a fully closed state by outputting a control signal to the second control valve 52V.

[0048] On the other hand, in step S12, when it is determined that the oil temperature TA is below a predetermined specified temperature TZ, the actuator 91 proceeds to step S31. In step S31, the actuator 91 controls the first control valve 51V to be fully open by outputting a control signal to the first control valve 51V. Furthermore, the actuator 91 controls the second control valve 52V to be fully open by outputting a control signal to the second control valve 52V. In other words, when it is determined that the oil temperature TA is below the specified temperature TZ, compared to the case where the oil temperature TA is above the specified temperature TZ, the actuator 91 increases the opening of the first control valve 51V. Furthermore, when it is determined that the oil temperature TA is below the specified temperature TZ, compared to the case where the oil temperature TA is above the specified temperature TZ, the actuator 91 increases the opening of the second control valve 52V.

[0049] <Effects of this implementation method> (1) According to this embodiment, when the oil temperature TA is below the specified temperature TZ, compared to the case where the oil temperature TA is above the specified temperature TZ, the exhaust gas flowing through the exhaust passage 10B is more easily introduced into the crankshaft chamber 10Z via the first connecting passage 51A and the second connecting passage 52A. Therefore, due to the heat exchange between the exhaust gas introduced into the crankshaft chamber 10Z via the first connecting passage 51A and the second connecting passage 52A and the oil stored in the crankshaft chamber 10Z, the oil temperature TA will rise. As a result, it is possible to prevent the viscosity of the oil supplied from the crankshaft chamber 10Z to various parts of the internal combustion engine 10 via the filter 81, the suction pipe 82 and the oil pump 83 from becoming too high.

[0050] It should be noted that the exhaust gas introduced into the crankcase 10Z via the first connecting passage 51A and the second connecting passage 52A sometimes contains unburned fuel. Therefore, if the internal combustion engine 10 is a gasoline engine, the mixing of unburned fuel with the engine oil stored in the crankcase 10Z may sometimes accelerate the deterioration of the engine oil stored in the crankcase 10Z. However, since the internal combustion engine 10 is a hydrogen engine, even if the exhaust gas contains unburned fuel, the unburned fuel is unlikely to mix with the engine oil stored in the crankcase 10Z. As a result, the accelerated deterioration of the engine oil stored in the crankcase 10Z due to unburned fuel in the exhaust gas can be suppressed. Furthermore, since the internal combustion engine 10 is a hydrogen engine, the amount of nitrogen oxides in the exhaust gas is less than that in a gasoline engine. As a result, the accelerated deterioration of the engine oil stored in the crankcase 10Z due to nitrogen oxides in the exhaust gas can be suppressed.

[0051] (2) When the internal combustion engine 10 is operating, the pressure inside the turbine impeller 47C in the turbine housing 47HC will increase accordingly. On the other hand, the pressure inside the connecting shaft 47B in the bearing housing 47HB is lower than the pressure inside the turbine impeller 47C in the turbine housing 47HC. Therefore, exhaust gas may sometimes enter the inside space of the connecting shaft 47B in the bearing housing 47HB from the inside space of the turbine housing 47HC through the connection between the turbine housing 47HC and the bearing housing 47HB.

[0052] In this respect, such as Figure 1 As shown, the first connecting passage 51A is connected to the internal space of the connecting shaft 47B in the bearing housing 47HB of the turbocharger 47. Therefore, exhaust gas entering the internal space of the connecting shaft 47B in the bearing housing 47HB from the internal space of the turbine housing 47HC is introduced into the crankshaft chamber 10Z via the first connecting passage 51A. This suppresses the leakage of exhaust gas entering the internal space of the connecting shaft 47B in the bearing housing 47HB to the outside of the internal combustion engine 10.

[0053] (3) such as Figure 1As shown, the second connecting passage 52A is connected to the upstream portion of the exhaust passage 10B relative to the turbine impeller 47C. Here, when the internal combustion engine 10 is operating, the pressure in the upstream portion of the exhaust passage 10B relative to the turbine impeller 47C is more likely to be higher than the pressure in the downstream portion of the exhaust passage 10B relative to the turbine impeller 47C. Therefore, compared to, for example, the case where the second connecting passage 52A is connected to the downstream portion of the exhaust passage 10B relative to the turbine impeller 47C, the amount of exhaust gas introduced into the crankshaft chamber 10Z via the second connecting passage 52A can be increased. It should be noted that if the amount of exhaust gas introduced into the crankshaft chamber 10Z via the second connecting passage 52A is large, the engine oil temperature TA can easily rise rapidly.

[0054] (4) such as Figure 2 As shown, when the oil temperature TA is determined to be below the specified temperature TZ, compared to the case where the oil temperature TA is determined to be above the specified temperature TZ, the actuator 91 reduces the opening of the variable nozzle device 47N. Here, the opening of the variable nozzle device 47N corresponds to the size of the exhaust flow path, i.e., the gas flow path, from the portion of the exhaust passage 10B relative to the turbine impeller 47C upstream to the turbine impeller 47C. Therefore, when the oil temperature TA is determined to be below the specified temperature TZ, compared to the case where the oil temperature TA is determined to be above the specified temperature TZ, the actuator 91 reduces the aforementioned gas flow path via the variable nozzle device 47N. Therefore, when the oil temperature TA is below the specified temperature TZ, the pressure in the portion of the exhaust passage 10B relative to the turbine impeller 47C upstream increases due to the reduction of the gas flow path via the variable nozzle device 47N. As a result, the amount of exhaust entering the first connecting passage 51A via the internal space of the turbine housing 47HC and the internal space of the bearing housing 47HB is easily increased. Furthermore, the amount of exhaust gas entering the second connecting passage 52A from the portion of the exhaust passage 10B upstream of the turbine impeller 47C is easily increased. As a result, when the oil temperature TA is below the specified temperature TZ, the amount of exhaust gas introduced into the crankshaft chamber 10Z via the first connecting passage 51A and the second connecting passage 52A can be further increased.

[0055] <Example of Change> This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined and implemented to the extent that they do not contradict each other technically.

[0056] • In the above embodiment, the oil temperature adjustment control can be modified. For example, the method of obtaining the oil temperature TA in step S11 can be changed. As a specific example, the actuator 91 can estimate the temperature of the oil stored in the crankshaft chamber 10Z based on the operating state of the internal combustion engine 10. Furthermore, the actuator 91 can obtain the estimated oil temperature as the oil temperature TA.

[0057] • For example, the specified temperature TZ in step S12 can be changed. That is, the specified temperature TZ is not limited to 80°C. As a specific example, the specified temperature TZ can be lower than 80°C or higher than 80°C.

[0058] • For example, the control structure of the first control valve 51V in step S21 can be changed. Specifically, in step S21, the actuator 91 can set the opening degree of the first control valve 51V to be larger than the fully closed state. In this case, the actuator 91 can change the opening degree of the first control valve 51V in step S21 within a range smaller than the opening degree of the first control valve 51V in step S31. Similarly, the control structure of the second control valve 52V in step S21 can also be changed.

[0059] • For example, the control structure of the first control valve 51V in step S31 can be changed. Specifically, in step S31, the actuator 91 can set the opening degree of the first control valve 51V to be smaller than the fully open state. In this case, the actuator 91 can change the opening degree of the first control valve 51V in step S31 within a range greater than the opening degree of the first control valve 51V in step S21. Alternatively, as a specific example, in step S31, the lower the oil temperature TA, the larger the opening degree of the first control valve 51V set by the actuator 91. In this case, the actuator 91 only needs to set the minimum value of the opening degree of the first control valve 51V in step S31 to be greater than the opening degree of the first control valve 51V in step S21. Similarly, the control structure of the second control valve 52V in step S31 can also be changed.

[0060] • For example, the control structure of the variable nozzle device 47N in step S32 can also be modified. Specifically, in step S32, the lower the oil temperature TA, the smaller the opening of the variable nozzle device 47N by the actuator 91. In other words, the lower the oil temperature TA, the smaller the gas flow path by the actuator 91 through the variable nozzle device 47N. In this case, the actuator 91 only needs to set the maximum value of the opening of the variable nozzle device 47N in step S32 to be less than the opening of the variable nozzle device 47N in step S22. Alternatively, similarly to step S22, in step S32, the actuator 91 can control the variable nozzle device 47N based on a base opening. In other words, the opening of the variable nozzle device 47N in step S32 can be the same as the opening of the variable nozzle device 47N in step S22. As an example, if the necessity of adjusting the opening of the variable nozzle device 47N according to the oil temperature TA is low, then even if the opening of the variable nozzle device 47N in step S32 is set to be the same as the opening of the variable nozzle device 47N in step S22, the impact is small.

[0061] • In the above embodiment, the structure of the vehicle 100 can also be modified. For example, the first connection path 51A, i.e., the first control valve 51V, can be omitted. Even in this case, as long as the internal combustion engine 10 has the second connection path 52A and the second control valve 52V, this technology can be applied.

[0062] • For example, the connection structure of the second connecting passage 52A can be changed. As a specific example, the first end of the second connecting passage 52A is connected to the exhaust port 22B instead of the exhaust pipe 42. That is, the connection position of the second connecting passage 52A can be changed as long as the second connecting passage 52A is connected to the upstream part of the exhaust passage 10B relative to the turbine impeller 47C.

[0063] • For example, the second connection path 52A and the second control valve 52V can be omitted. Even in this case, this technology can be applied as long as the internal combustion engine 10 has the first connection path 51A and the first control valve 51V.

[0064] • For example, the structure of the turbocharger 47 can be modified. Specifically, the turbine housing 47HC of the turbocharger 47 can have a main passage containing the turbine impeller 47C and a bypass passage bypassing the turbine impeller 47C. Furthermore, the turbocharger 47 can replace the variable nozzle device 47N, or on this basis, have an exhaust gas bypass valve that opens and closes the flow path of the bypass passage. In this case, in steps S22 and S32 of the oil temperature adjustment control, the actuator 91 of the control device 90 can replace the variable nozzle device 47N, or on this basis, control the exhaust gas bypass valve. Specifically, when it is determined that the oil temperature TA is below a specified temperature TZ, compared to when it is determined that the oil temperature TA is above the specified temperature TZ, the actuator 91 reduces the opening of the exhaust gas bypass valve. Therefore, when the oil temperature TA is below the specified temperature TZ, because the opening of the exhaust gas bypass valve is reduced, the pressure in the portion of the exhaust passage 10B upstream of the turbine impeller 47C increases. As a result, when the oil temperature TA is below the specified temperature TZ, the amount of exhaust gas introduced into the crankshaft chamber 10Z via the first connecting passage 51A and the second connecting passage 52A can be further increased.

[0065] • For example, the turbocharger 47 can be omitted. In this case, the first end of the connecting passage can be connected, for example, to the middle of the exhaust pipe 42. And the second end of the connecting passage can be connected to the crankshaft housing 10Z. In addition, the control valve can be located, for example, in the middle of the connecting passage.

[0066] • For example, the structure of the control device 90 can be modified. Specifically, the control device 90 can be configured as a circuit including one or more processors that perform various processes according to a computer program (software). It should be noted that the control device 90 can be configured as a circuit including one or more special-purpose hardware circuits, such as application-specific integrated circuits (ASICs), or combinations thereof, that perform at least a portion of the various processes. The processor includes a CPU and memories such as RAM and ROM. The memory stores program code or instructions configured to cause the CPU to perform processes. Memory, or computer-readable medium, includes all media accessible to general-purpose or special-purpose computers. Explanation of reference numerals in the attached figures

[0067] 10…Internal Combustion Engine 10A…Intake Passage 10B…Exhaust Passage 10C…Combustion Chamber 10Z…Crankshaft Chamber 21…Cylinder Head Cover 22…Cylinder Head 22A…Intake Port 22B…Exhaust Port 22C…Combustion Recess 23…Cylinder Block 23A…Cylinder 24…Crankcase 25…Oil Pan 31…Piston 32…Connecting Rod 33…Crankshaft 36…Fuel Injection Valve 37…Ignition Device 38…Throttle Valve 39…Water Injection Valve 41…Intake Manifold 42…Exhaust Manifold 46…Air Filter 47…Turbocharger 47A…Compressor Impeller 47B…Connecting Shaft 47C…Turbine Impeller 47HA…Compressor Housing 47HB…Bearing Housing 47H C… Turbine housing 47N… Variable nozzle device 48… Intercooler 51A… First connection 51V… First control valve 52A… Second connection 52V… Second control valve 60Z… Inlet passage 61… First inlet pipe 62… Second inlet pipe 63… Separator 70Z… Discharge passage 71… First discharge pipe 72… Second discharge pipe 73… Separator 81… Filter 82… Suction pipe 83… Oil pump 86… Accelerator operation sensor 87… Vehicle speed sensor 88… Crankshaft angle sensor 89… Oil temperature sensor 90… Control device 91… Actuator 92… Storage device 92A… Control program 100… Vehicle.

Claims

1. A control device for an internal combustion engine, with the internal combustion engine as the target, The internal combustion engine has the following features: A cylinder used to burn hydrogen as fuel; An intake passage is used to introduce intake air into the cylinder; An exhaust passage for discharging exhaust gas from the cylinder; A crankshaft chamber that houses the crankshaft and stores engine oil; A portion of the exhaust gas after it has circulated through the exhaust passage is introduced into the connecting passage of the crankshaft chamber; and A control valve that opens and closes the flow path of the connecting path. The control unit of the internal combustion engine performs the following processes: The temperature of the oil stored in the crankshaft chamber is obtained, i.e., the oil temperature. Determine whether the obtained oil temperature is below a predetermined specified temperature; When the oil temperature is determined to be below the specified temperature, the opening of the control valve is increased compared to when the oil temperature is determined to be above the specified temperature.

2. The control device for an internal combustion engine according to claim 1, wherein, The internal combustion engine includes a turbocharger, which uses the exhaust flow from the exhaust passage to compress the intake air flowing in the intake passage and supply it downstream. The turbocharger includes: The compressor housing that forms part of the intake passage; The turbine housing forms part of the exhaust passage; A bearing housing that connects the compressor housing and the turbine housing; The compressor impeller is located inside the compressor housing; The turbine impeller is located inside the turbine housing; and The connecting shaft located inside the bearing housing and connecting the compressor impeller and the turbine impeller, The connecting path is connected to the internal space of the connecting shaft in the bearing housing.

3. The control device for an internal combustion engine according to claim 1, wherein, The internal combustion engine includes a turbocharger, which uses the exhaust flow from the exhaust passage to compress the intake air flowing in the intake passage and supply it downstream. The turbocharger includes: The compressor housing that forms part of the intake passage; The turbine housing forms part of the exhaust passage; A bearing housing that connects the compressor housing and the turbine housing; The compressor impeller is located inside the compressor housing; The turbine impeller is located inside the turbine housing; and The connecting shaft located inside the bearing housing and connecting the compressor impeller and the turbine impeller, The connecting passage is connected to the upstream portion of the exhaust passage relative to the turbine impeller.

4. The control device for an internal combustion engine according to claim 2 or 3, wherein, The turbocharger includes a variable nozzle device located inside the turbine housing, which adjusts the size of the exhaust flow path, i.e., the gas flow path, leading to the turbine impeller. The control device of the internal combustion engine performs the following processing: when it is determined that the oil temperature is below the specified temperature, compared with the case where the oil temperature is determined to be above the specified temperature, the opening of the control valve is increased, and the gas flow path is reduced by the variable nozzle device.

5. The control device for an internal combustion engine according to claim 2 or 3, wherein, The turbine housing has a main passage where the turbine impeller is located and a bypass passage that bypasses the turbine impeller. The turbocharger includes an exhaust gas bypass valve that opens and closes the flow path of the bypass passage. The control device of the internal combustion engine performs the following processing: when it is determined that the oil temperature is below the specified temperature, compared with the case where the oil temperature is determined to be above the specified temperature, the opening of the control valve is increased and the opening of the exhaust bypass valve is decreased.

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