Control device for internal combustion engine
The control device addresses high viscosity issues in hydrogen-fueled engines by regulating exhaust gas flow into the crank chamber based on oil temperature, ensuring optimal engine performance.
Patent Information
- Application Number
- JP2024112526
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-07-12
- Publication Date
- 2026-01-23
AI Technical Summary
In internal combustion engines, particularly those using hydrogen as fuel, low oil temperature in the crank chamber leads to excessively high viscosity, causing increased friction in engine components.
A control device that adjusts the opening of control valves and the variable nozzle device based on oil temperature to regulate the introduction of exhaust gas into the crank chamber, thereby maintaining optimal oil viscosity.
Prevents excessively high viscosity of oil supplied to engine components, reducing friction and maintaining engine efficiency by controlling oil temperature through exhaust gas introduction.
Smart Images
Figure 2026011702000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to a control device for an internal combustion engine. [Background technology]
[0002] The internal combustion engine of Patent Document 1 includes a cylinder, an intake passage, an exhaust passage, a crank chamber, and a crankshaft. The cylinder is a space for burning a mixture of fuel and intake air. The intake passage introduces intake air into the cylinder. The exhaust passage discharges exhaust gas from the cylinder. The crank chamber houses the crankshaft. The crank chamber also stores oil. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Patent Publication No. 2021-127704 Summary of the Invention [Problem to be solved by the invention]
[0004] In an internal combustion engine such as that disclosed in Patent Document 1, oil stored in a crank chamber is generally supplied to various parts of the engine. Here, if the temperature of the oil stored in the crank chamber is low, the viscosity of the oil supplied from the crank chamber to various parts of the engine may become excessively high. Furthermore, if such highly viscous oil is supplied to various parts of the engine, the friction in each part of the engine may become excessively large. [Means for solving the problem]
[0005] A control device for an internal combustion engine to solve the above problem is targeted at an internal combustion engine that has a cylinder for burning hydrogen as fuel, an intake passage that introduces intake air into the cylinder, an exhaust passage that discharges exhaust from the cylinder, a crank chamber that accommodates a crankshaft and stores oil, a connecting passage that introduces a portion of the exhaust that has flowed through the exhaust passage into the crank chamber, and a control valve that opens and closes the flow path of the connecting passage, and performs the following operations: acquires an oil temperature that is the temperature of oil stored in the crank chamber; determines whether the acquired oil temperature is below a predetermined specified temperature; and, if it is determined that the oil temperature is below the specified temperature, increases the opening of the control valve compared to when it is determined that the oil temperature is higher than the specified temperature. [Effects of the Invention]
[0006] According to the above configuration, the viscosity of the oil supplied from the crank chamber to each part of the internal combustion engine can be prevented from becoming excessively high. [Brief explanation of the drawings]
[0007] [Figure 1] FIG. 1 is a schematic diagram of a vehicle. [Figure 2] FIG. 2 is a flowchart showing the oil temperature adjustment control. DETAILED DESCRIPTION OF THE INVENTION
[0008] <Vehicle Overview> An embodiment of the present invention will be described below with reference to Figures 1 and 2. First, a general configuration of a vehicle 100 will be described. In the following description, the up and down directions will be described based on the up and down of the vehicle 100. An example of the vehicle 100 is a passenger car.
[0009] 1, a vehicle 100 includes an internal combustion engine 10. The internal combustion engine 10 includes a head cover 21, a cylinder head 22, a cylinder block 23, a crankcase 24, and an oil pan 25. The internal combustion engine 10 also includes a plurality of pistons 31, a plurality of connecting rods 32, a crankshaft 33, an intake pipe 41, and an exhaust pipe 42.
[0010] The cylinder block 23 has four cylinders 23A and four upper spaces 23B as internal spaces of the cylinder block 23. The cylinders 23A extend from the upper end of the cylinder block 23 to near the center in the vertical direction. The cylinders 23A are spaces 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 ends of the cylinders 23A to the lower end of the cylinder block 23. The pistons 31 are located inside the cylinders 23A. The pistons 31 are connected to a crankshaft 33 via connecting rods 32. The pistons 31 reciprocate inside the cylinders 23A as the mixture of fuel and intake air burns in the cylinders 23A. The reciprocating motion of the pistons 31 rotates the crankshaft 33. Note that FIG. 1 shows only one cylinder 23A as a representative.
[0011] The crankcase 24 is connected to the lower end of the cylinder block 23. The crankcase 24 has a so-called ladder frame structure. Therefore, the crankcase 24 has four lower spaces 24A as internal spaces of the crankcase 24. 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 rotatably support the crankshaft 33 sandwiched between them.
[0012] The oil pan 25 is connected to the lower end of the crankcase 24. The oil pan 25 is shaped like a generally rectangular box with a bottom. Therefore, the oil pan 25 has an oil space 25A as an internal space of the oil pan 25. 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 form a crank chamber 10Z of the internal combustion engine 10. The crank chamber 10Z accommodates 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 has four intake ports 22A, four exhaust ports 22B, and four combustion recesses 22C as an internal space of the cylinder head 22. The combustion recesses 22C are recessed upward from the lower surface of the cylinder head 22. The combustion recesses 22C are connected to the upper ends of the cylinders 23A. The combustion recesses 22C, the cylinders 23A, and the pistons 31 define a combustion chamber 10C.
[0014] A first end of the intake port 22A is connected to the combustion recess 22C. A second end of the intake port 22A opens to a side surface of the cylinder head 22. An 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 introduces the intake air that has flowed through the intake pipe 41 into the cylinder 23A.
[0015] A first end of the exhaust port 22B is connected to the combustion recess 22C. A second end of the exhaust port 22B opens to a side surface of the cylinder head 22. An 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 to the exhaust pipe 42. The exhaust pipe 42 discharges the exhaust gas that has flowed through the exhaust port 22B to the outside of the internal combustion engine 10.
[0016] The head cover 21 is connected to the upper end of the cylinder head 22. The head cover 21 covers the cylinder head 22. The head cover 21, together with the cylinder head 22, defines an accommodation space 21A. The accommodation space 21A accommodates a valve mechanism and the like (not shown).
[0017] The internal combustion engine 10 includes a plurality of intake valves 34 , a plurality of exhaust valves 35 , a plurality of fuel injection valves 36 , and a plurality of ignition devices 37 . The intake valve 34 is located at the connection between the intake port 22A and the combustion recess 22C. The intake valve 34 opens and closes the downstream end of the intake port 22A using power from a valve mechanism (not shown). The exhaust valve 35 is located at the connection between the exhaust port 22B and the combustion recess 22C. The exhaust valve 35 opens and closes the upstream end of the exhaust port 22B using power from a valve mechanism (not shown).
[0018] The tip of the fuel injection valve 36 is located midway through the intake port 22A. The fuel injection valve 36 is supplied with hydrogen stored in a fuel tank (not shown). The fuel injection valve 36 injects hydrogen as fuel into the intake port 22A. As a result, hydrogen is supplied to the cylinder 23A via the intake port 22A and the combustion recess 22C. The tip of the ignition device 37 is located in the combustion recess 22C. The ignition device 37 ignites the mixture of fuel and intake air by spark discharge.
[0019] The internal combustion engine 10 includes a throttle valve 38, a plurality of water injection valves 39, an air cleaner 46, a turbocharger 47, and an intercooler 48. The turbocharger 47 includes a compressor wheel 47A, a connecting shaft 47B, and a turbine wheel 47C. The turbocharger 47 also 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 form 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 form an exhaust passage 10B that discharges exhaust gas from the cylinder 23A. The bearing housing 47HB connects the compressor housing 47HA and the turbine housing 47HC.
[0021] The compressor wheel 47A is located inside the compressor housing 47HA. In other words, the compressor housing 47HA houses the compressor wheel 47A in the internal space of the compressor housing 47HA. The turbine wheel 47C is located inside the turbine housing 47HC. In other words, the turbine housing 47HC houses the turbine wheel 47C in the internal space of the turbine housing 47HC. The connecting shaft 47B is located inside the bearing housing 47HB. In other words, the bearing housing 47HB houses the connecting shaft 47B in the internal space of the bearing housing 47HB. A first end of the connecting shaft 47B is connected to the compressor wheel 47A. Furthermore, a second end of the connecting shaft 47B is connected to the turbine wheel 47C. In other words, the connecting shaft 47B connects the compressor wheel 47A and the turbine wheel 47C.
[0022] When the turbine wheel 47C rotates due to the flow of exhaust gas in the exhaust passage 10B, the compressor wheel 47A rotates together with the turbine wheel 47C via the connecting shaft 47B. As a result, the intake air compressed by the compressor wheel 47A is supplied to the intake passage 10A downstream of the compressor wheel 47A. In other words, the turbocharger 47 uses the flow of exhaust gas in the exhaust passage 10B to compress the intake air flowing through the intake passage 10A and supply it downstream.
[0023] The variable nozzle device 47N is located in the internal space of the turbine housing 47HC. Specifically, the variable nozzle device 47N is located near the turbine wheel 47C within the internal space of the turbine housing 47HC. The variable nozzle device 47N is shaped like a ring that surrounds the turbine wheel 47C. The variable nozzle device 47N adjusts the size of the gas flow path, which is the exhaust flow path that leads from the upstream portion of the turbine wheel 47C in the exhaust passage 10B to the turbine wheel 47C. Hereinafter, the size of the gas flow path is also referred to as the opening degree of the variable nozzle device 47N. The turbocharger 47 equipped with the variable nozzle device 47N may also be called a variable geometry turbocharger, a variable nozzle turbocharger, etc.
[0024] The air cleaner 46 is located in the intake pipe 41 at a portion upstream of the compressor wheel 47A. The air cleaner 46 collects foreign matter contained in the intake air flowing through the intake pipe 41. The intercooler 48 is located in the intake pipe 41 at a portion downstream of the compressor wheel 47A. The intercooler 48 cools the intake air compressed by the compressor wheel 47A. The throttle valve 38 is located in the intake pipe 41 at a portion downstream of the intercooler 48. The throttle valve 38 adjusts the amount of intake air flowing through the intake pipe 41.
[0025] The tip of the water injector 39 is located midway through the intake port 22A. Water stored in a water tank (not shown) is supplied to the water injector 39. The water injector 39 injects water into the intake port 22A. When the injected water evaporates, the intake port 22A is cooled, thereby cooling the intake air introduced from the intake port 22A into the cylinder 23A.
[0026] As shown in FIG. 1 , the internal combustion engine 10 includes a strainer 81, a suction pipe 82, and an oil pump 83. In this embodiment, the oil pump 83 is attached to the crankcase 24. The oil pump 83 is a so-called mechanical pump that operates using power from the crankshaft 33. A first end of the suction pipe 82 is connected to the oil pump 83. A portion of the suction pipe 82, including its second end, is located in the crankcase 10Z. A portion of the suction pipe 82, including its second end, extends generally downward. The second end of the suction pipe 82 is connected to the strainer 81. The strainer 81 has a function of removing foreign matter contained in the oil. A lower end of the strainer 81 is spaced apart from the bottom surface of the oil pan 25. The strainer 81 is located inside the oil stored in the crankcase 10Z. When the oil pump 83 operates, oil in the crankcase 10Z is sucked through the strainer 81. The oil sucked through the strainer 81 is supplied to each part of the internal combustion engine 10 via a suction pipe 82 and an oil pump 83 .
[0027] As shown in FIG. 1, 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 accommodation space 21A. The separator 63 collects oil contained in the gas flowing inside the separator 63. A first end of the first lead-in pipe 61 is connected to the separator 63. A second end of the first lead-in pipe 61 is connected to a portion of the intake pipe 41 that is downstream of the compressor wheel 47A and upstream of the intercooler 48. A first end of the second lead-in pipe 62 is connected to the separator 63. A second end of the second lead-in pipe 62 is connected to the crank chamber 10Z.
[0028] In this embodiment, the space defined by the first inlet pipe 61, the second inlet pipe 62, and the separator 63 functions as an inlet passage 60Z that introduces a portion of the intake air flowing through the intake passage 10A into the crank chamber 10Z.
[0029] As shown in FIG. 1, 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 accommodation space 21A. The separator 73 collects oil contained in the gas flowing inside the separator 73. 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 crank chamber 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 a portion of the intake pipe 41 that is upstream of the compressor wheel 47A and downstream of the air cleaner 46.
[0030] In this embodiment, the space defined by the first discharge pipe 71, the second discharge pipe 72, and the separator 73 functions as a discharge passage 70Z that discharges gas present in the crank chamber 10Z to the intake passage 10A.
[0031] When the internal combustion engine 10 is operating, the compressor wheel 47A of the turbocharger 47 compresses the intake air flowing through the intake passage 10A and supplies it downstream in response to the flow of exhaust gas through the exhaust passage 10B. As a result, the pressure in the portion of the intake passage 10A downstream of the compressor wheel 47A becomes higher than the pressure in the portion of the intake passage 10A upstream of the compressor wheel 47A. Some of the intake air flowing through the intake passage 10A is introduced into the crank chamber 10Z through the space defined by the first introduction pipe 61, the separator 63, and the second introduction pipe 62, i.e., through the introduction passage 60Z. When the intake air is introduced into the crank chamber 10Z through the introduction passage 60Z as described above, the pressure in the crank chamber 10Z increases accordingly. The gas present in the crank chamber 10Z is then discharged through the space defined by the first discharge pipe 71, the separator 73, and the second discharge pipe 72, i.e., through the discharge passage 70Z, to the upstream portion of the intake passage 10A relative to the compressor wheel 47A.
[0032] As shown in FIG. 1, the internal combustion engine 10 includes a first communication passage 51A, a first control valve 51V, a second communication passage 52A, and a second control valve 52V. A first end of the first communication passage 51A is connected to the internal space of the bearing housing 47HB in which the connecting shaft 47B is located. A second end of the first communication passage 51A is connected to the crank chamber 10Z. The first control valve 51V is located midway through the first communication passage 51A. The first control valve 51V opens and closes the flow path of the first communication passage 51A.
[0033] A first end of the second communication passage 52A is connected to a portion of the exhaust pipe 42 that is upstream of the turbine wheel 47C. In other words, the first end of the second communication passage 52A is connected to a portion of the exhaust passage 10B that is upstream of the turbine wheel 47C. A second end of the second communication passage 52A is connected to the crank chamber 10Z. The second control valve 52V is located midway through the second communication passage 52A. The second control valve 52V opens and closes the flow path of the second communication passage 52A.
[0034] In this embodiment, the first communication passage 51A and the second communication passage 52A are each an example of a communication passage that introduces a portion of the exhaust gas that has flowed through the exhaust passage 10B into the crank chamber 10Z. Also, the first control valve 51V and the second control valve 52V are each an example of a control valve that opens and closes the flow path of the communication passage.
[0035] As shown in FIG. 1, the internal combustion engine 10 is equipped with an accelerator operation amount sensor 86 , a vehicle speed sensor 87 , a crank angle sensor 88 , and an oil temperature sensor 89 . The accelerator operation amount sensor 86 detects the accelerator operation amount ACC, which is the amount of operation of the accelerator pedal operated by the driver of the vehicle 100. The vehicle speed sensor 87 detects the vehicle speed SP, which is the speed of the vehicle 100. The crank angle sensor 88 detects the crank angle SC, which is the angular position of the crankshaft 33. The oil temperature sensor 89 detects the oil temperature TA, which is the temperature of the oil stored in the crank chamber 10Z. In this embodiment, the oil temperature sensor 89 is attached to the oil pan 25.
[0036] 1, the vehicle 100 is equipped with a control device 90. The control device 90 acquires various pieces of information from an accelerator operation amount sensor 86, a vehicle speed sensor 87, a crank angle sensor 88, and an 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 readable and writable volatile RAM, and a readable and writable non-volatile storage. The storage device 92 stores various programs and various data in advance. Specifically, the storage device 92 stores a control program 92A in advance as one of the various programs. The execution device 91 executes the control program 92A stored in the storage device 92 to perform various processes described below.
[0038] The execution unit 91 of the control device 90 calculates a vehicle required driving force, which is a required value of driving force necessary for the vehicle 100 to travel, based on the accelerator operation amount ACC and the vehicle speed SP. The execution unit 91 also calculates an engine rotation speed NE, which is the rotation speed of the crankshaft 33, based on the crank angle SC. The execution unit 91 then controls the internal combustion engine 10 based on the vehicle required driving force and the engine rotation speed NE, etc. Specifically, the execution unit 91 outputs control signals to the internal combustion engine 10 to control the fuel injection valve 36, the ignition device 37, the throttle valve 38, the water injection valve 39, the turbocharger 47, etc. The execution unit 91 can also control a first control valve 51V, a second control valve 52V, etc., by outputting control signals to the internal combustion engine 10.
[0039] <Oil temperature adjustment control> Next, the oil temperature adjustment control executed by the control device 90 will be described with reference to Fig. 2. This oil temperature adjustment control is control for adjusting the oil temperature TA of the crank chamber 10Z. In this embodiment, the execution device 91 of the control device 90 starts the oil temperature adjustment control at each predetermined control cycle, with the necessary condition being that the internal combustion engine 10 is operating.
[0040] 2, when the execution unit 91 of the control device 90 starts oil temperature regulation control, it executes the process of step S11. In step S11, the execution unit 91 acquires the oil temperature TA at the start of the current oil temperature regulation control. After step S11, the execution unit 91 proceeds to step S12.
[0041] In step S12, the execution unit 91 determines whether the oil temperature TA acquired in step S11 is higher than a predetermined specified temperature TZ. In this embodiment, the specified temperature TZ is a threshold value of the oil temperature TA for determining whether the viscosity of the oil stored in the crank chamber 10Z needs to be reduced. An example of the specified temperature TZ is about 80°C. If the execution unit 91 determines in step S12 that the oil temperature TA is higher than the specified temperature TZ (S12: YES), the execution unit 91 proceeds to step S21.
[0042] In step S21, the execution unit 91 controls the first control valve 51V to a fully closed state by outputting a control signal to the first control valve 51V. The execution unit 91 also 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 execution unit 91 advances the process to step S22.
[0043] In step S22, the execution unit 91 controls the variable nozzle device 47N based on a base opening degree that corresponds to the operating state of the internal combustion engine 10. For example, the execution unit 91 calculates the base opening degree for the variable nozzle device 47N by correlating the vehicle required driving force, engine rotation speed NE, etc. with a predetermined control map. The execution unit 91 then controls the variable nozzle device 47N by outputting a control signal that corresponds to the calculated base opening degree to the variable nozzle device 47N. After step S22, the execution unit 91 ends the current oil temperature adjustment control.
[0044] On the other hand, if the execution unit 91 determines in step S12 that the oil temperature TA is equal to or lower than the specified temperature TZ (S12: NO), the execution unit 91 advances the process to step S31.
[0045] In step S31, the executing device 91 controls the first control valve 51V to a fully open state by outputting a control signal to the first control valve 51V. In other words, when the executing device 91 determines that the oil temperature TA is equal to or lower than the specified temperature TZ, the executing device 91 increases the opening degree of the first control valve 51V compared to when the executing device 91 determines that the oil temperature TA is higher than the specified temperature TZ. In addition, the executing device 91 controls the second control valve 52V to a fully open state by outputting a control signal to the second control valve 52V. In other words, when the executing device 91 determines that the oil temperature TA is equal to or lower than the specified temperature TZ, the executing device 91 increases the opening degree of the second control valve 52V compared to when the executing device 91 determines that the oil temperature TA is higher than the specified temperature TZ. After step S31, the executing device 91 proceeds to step S32.
[0046] In step S32, the execution unit 91 controls the variable nozzle device 47N based on the corrected opening obtained by correcting the base opening. For example, the execution unit 91 calculates the base opening for the variable nozzle device 47N by correlating the vehicle's required driving force, engine speed NE, and the like with a predetermined control map. Furthermore, the execution unit 91 calculates a corrected opening that is smaller than the base opening by a predetermined constant value. The execution unit 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 described above, the opening of the variable nozzle device 47N corresponds to the size of the gas flow path, which is the exhaust flow path from the upstream portion of the turbine wheel 47C in the exhaust passage 10B to the turbine wheel 47C. Therefore, when the execution unit 91 determines that the oil temperature TA is equal to or lower than the specified temperature TZ, the execution unit 91 reduces the size of the gas flow path using the variable nozzle device 47N compared to when the execution unit 91 determines that the oil temperature TA is higher than the specified temperature TZ. After step S32, the execution unit 91 ends the current oil temperature adjustment control.
[0047] <Operation of this embodiment> 2, when the internal combustion engine 10 is operating, the execution unit 91 of the control device 90 executes oil temperature adjustment control. Here, if the execution unit 91 determines in step S12 that the oil temperature TA is higher than a predetermined specified temperature TZ, the process proceeds to step S21. In step S21, the execution unit 91 controls the first control valve 51V to a fully closed state by outputting a control signal to the first control valve 51V. In addition, the execution unit 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, if the execution device 91 determines in step S12 that the oil temperature TA is equal to or lower than a predetermined specified temperature TZ, the process proceeds to step S31. In step S31, the execution device 91 controls the first control valve 51V to a fully open state by outputting a control signal to the first control valve 51V. The execution device 91 also controls the second control valve 52V to a fully open state by outputting a control signal to the second control valve 52V. In other words, if the execution device 91 determines that the oil temperature TA is equal to or lower than the specified temperature TZ, the execution device 91 increases the opening degree of the first control valve 51V compared to when the execution device 91 determines that the oil temperature TA is higher than the specified temperature TZ. Furthermore, if the execution device 91 determines that the oil temperature TA is equal to or lower than the specified temperature TZ, the execution device 91 increases the opening degree of the second control valve 52V compared to when the execution device 91 determines that the oil temperature TA is higher than the specified temperature TZ.
[0049] <Effects of this embodiment> (1) According to this embodiment, when the oil temperature TA is equal to or lower than the specified temperature TZ, the exhaust gas that has flowed through the exhaust passage 10B via the first communication passage 51A and the second communication passage 52A is more likely to be introduced into the crank chamber 10Z than when the oil temperature TA is higher than the specified temperature TZ. Therefore, the oil temperature TA increases due to heat exchange between the exhaust gas introduced into the crank chamber 10Z via the first communication passage 51A and the second communication passage 52A and the oil stored in the crank chamber 10Z. This prevents the viscosity of the oil supplied from the crank chamber 10Z to each component of the internal combustion engine 10 via the strainer 81, the suction pipe 82, and the oil pump 83 from becoming excessively high.
[0050] Note that the exhaust gas introduced into the crank chamber 10Z via the first communication passage 51A and the second communication passage 52A may contain unburned fuel. Therefore, if the internal combustion engine 10 were a gasoline engine, mixing of the unburned fuel with the oil stored in the crank chamber 10Z could accelerate deterioration of the oil stored in the crank chamber 10Z. However, because the internal combustion engine 10 is a hydrogen engine, even if unburned fuel is contained in the exhaust gas, the unburned fuel and the oil stored in the crank chamber 10Z are unlikely to mix. As a result, deterioration of the oil stored in the crank chamber 10Z due to unburned fuel contained in the exhaust gas is suppressed. Furthermore, because the internal combustion engine 10 is a hydrogen engine, the amount of nitrogen oxides contained in the exhaust gas is smaller than, for example, a gasoline engine. As a result, deterioration of the oil stored in the crank chamber 10Z due to nitrogen oxides contained in the exhaust gas is suppressed.
[0051] (2) When the internal combustion engine 10 is operating, the pressure in the internal space of the turbine housing 47HC where the turbine wheel 47C is located becomes correspondingly high. Meanwhile, the pressure in the internal space of the bearing housing 47HB where the connecting shaft 47B is located is lower than the pressure in the internal space of the turbine housing 47HC where the turbine wheel 47C is located. Therefore, exhaust gas may reach the internal space of the bearing housing 47HB where the connecting shaft 47B is located from the internal space of the turbine housing 47HC via the connection between the turbine housing 47HC and the bearing housing 47HB.
[0052] 1, the first communication passage 51A is connected to the internal space of the bearing housing 47HB in the turbocharger 47, in which the connecting shaft 47B is located. Therefore, exhaust gas that reaches the internal space of the turbine housing 47HC in which the connecting shaft 47B is located is introduced into the crank chamber 10Z via the first communication passage 51A. This prevents the exhaust gas that reaches the internal space of the bearing housing 47HB in which the connecting shaft 47B is located from leaking to the outside of the internal combustion engine 10.
[0053] (3) As shown in FIG. 1 , the second communication passage 52A is connected to a portion of the exhaust passage 10B upstream of the turbine wheel 47C. When the internal combustion engine 10 is operating, the pressure in the portion of the exhaust passage 10B upstream of the turbine wheel 47C tends to be higher than the pressure in the portion of the exhaust passage 10B downstream of the turbine wheel 47C. Therefore, the amount of exhaust gas introduced into the crank chamber 10Z via the second communication passage 52A can be increased compared to, for example, when the second communication passage 52A is connected to a portion of the exhaust passage 10B downstream of the turbine wheel 47C. Note that if the amount of exhaust gas introduced into the crank chamber 10Z via the second communication passage 52A is increased in this manner, the oil temperature TA tends to be increased more quickly.
[0054] (4) As shown in FIG. 2, when the execution device 91 determines that the oil temperature TA is equal to or lower than the specified temperature TZ, the execution device 91 reduces the opening of the variable nozzle device 47N compared to when the execution device 91 determines that the oil temperature TA is higher than the specified temperature TZ. Here, the opening of the variable nozzle device 47N corresponds to the size of the gas flow path, which is the exhaust flow path from the portion of the exhaust passage 10B upstream of the turbine wheel 47C to the turbine wheel 47C. Therefore, when the execution device 91 determines that the oil temperature TA is equal to or lower than the specified temperature TZ, the execution device 91 reduces the size of the gas flow path using the variable nozzle device 47N compared to when the execution device 91 determines that the oil temperature TA is higher than the specified temperature TZ. Therefore, when the oil temperature TA is equal to or lower than the specified temperature TZ, the gas flow path is reduced by the variable nozzle device 47N, which increases the pressure in the portion of the exhaust passage 10B upstream of the turbine wheel 47C. This tends to increase the amount of exhaust gas that reaches the first communication passage 51A via the internal space of the turbine housing 47HC and the internal space of the bearing housing 47HB. Furthermore, the amount of exhaust gas flowing from the upstream portion of the exhaust passage 10B relative to the turbine wheel 47C to the second communication passage 52A is likely to increase. As a result, when the oil temperature TA is equal to or lower than the specified temperature TZ, the amount of exhaust gas introduced into the crank chamber 10Z via the first communication passage 51A and the second communication passage 52A can be further increased.
[0055] <Example of change> This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.
[0056] In the above embodiment, the oil temperature adjustment control may be changed. For example, the manner in which the oil temperature TA is acquired in step S11 may be changed. As a specific example, the execution unit 91 estimates the temperature of the oil stored in the crank chamber 10Z based on the operating state of the internal combustion engine 10. Then, the execution unit 91 may acquire 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 may be lower or higher than 80°C.
[0058] For example, the control configuration of the first control valve 51V in step S21 may be changed. As a specific example, in step S21, the execution device 91 may increase the opening of the first control valve 51V beyond the fully closed state. In this case, the execution device 91 may change the opening of the first control valve 51V in step S21 to a value less than the opening of the first control valve 51V in step S31. Note that, similarly to the above, the control configuration of the second control valve 52V in step S21 may be changed.
[0059] For example, the control configuration of the first control valve 51V in step S31 may be changed. As a specific example, in step S31, the execution device 91 may reduce the opening of the first control valve 51V from its fully open state. In this case, the execution device 91 may change the opening of the first control valve 51V in step S31 within a range greater than the opening of the first control valve 51V in step S21. Also, as a specific example, in step S31, the execution device 91 may increase the opening of the first control valve 51V the lower the oil temperature TA. In this case, the execution device 91 may set the minimum value of the opening of the first control valve 51V in step S31 to be greater than the opening of the first control valve 51V in step S21. Note that, similarly to the above, the control configuration of the second control valve 52V in step S31 may be changed.
[0060] For example, the control configuration of the variable nozzle device 47N in step S32 may be changed. As a specific example, in step S32, the executing unit 91 may reduce the opening of the variable nozzle device 47N as the oil temperature TA decreases. In other words, the executing unit 91 may reduce the gas flow path by the variable nozzle device 47N as the oil temperature TA decreases. In this case, the executing unit 91 may set the maximum opening of the variable nozzle device 47N in step S32 to be smaller than the opening of the variable nozzle device 47N in step S22. Also, as a specific example, in step S32, the executing unit 91 may control the variable nozzle device 47N based on the base opening, as in step S22. In other words, the opening of the variable nozzle device 47N in step S32 may be set to the same as the opening of the variable nozzle device 47N in step S22. As an example, if there is little need to adjust the opening degree of the variable nozzle device 47N according to the oil temperature TA, the impact of setting the opening degree of the variable nozzle device 47N in step S32 to the same as the opening degree of the variable nozzle device 47N in step S22 will be small.
[0061] In the above embodiment, the configuration of the vehicle 100 may be changed. For example, the first communication passage 51A and the first control valve 51V may be omitted. Even in this case, the present technology can be applied as long as the internal combustion engine 10 includes the second communication passage 52A and the second control valve 52V.
[0062] For example, the connection configuration of the second communication passage 52A may be changed. As a specific example, the first end of the second communication passage 52A may be connected to the exhaust port 22B instead of the exhaust pipe 42. In other words, as long as the second communication passage 52A is connected to a portion of the exhaust passage 10B that is upstream of the turbine wheel 47C, the connection point of the second communication passage 52A may be changed.
[0063] For example, the second communication passage 52A and the second control valve 52V may be omitted. Even in this case, the present technology can be applied as long as the internal combustion engine 10 includes the first communication passage 51A and the first control valve 51V.
[0064] For example, the configuration of the turbocharger 47 may be modified. Specifically, the turbine housing 47HC of the turbocharger 47 may include a main passage in which the turbine wheel 47C is located and a bypass passage that bypasses the turbine wheel 47C. The turbocharger 47 may include a wastegate valve that opens and closes the flow path of the bypass passage instead of, or in addition to, the variable nozzle device 47N. In this case, in steps S22 and S32 of the oil temperature regulation control, the execution unit 91 of the control device 90 may control the wastegate valve instead of, or in addition to, the variable nozzle device 47N. Specifically, when the execution unit 91 determines that the oil temperature TA is equal to or lower than the specified temperature TZ, the execution unit 91 may reduce the opening of the wastegate valve compared to when the execution unit 91 determines that the oil temperature TA is higher than the specified temperature TZ. As a result, when the oil temperature TA is equal to or lower than the specified temperature TZ, the reduction in the opening of the wastegate valve increases the pressure in the portion of the exhaust passage 10B upstream of the turbine wheel 47C. As a result, when the oil temperature TA is equal to or lower than the specified temperature TZ, the amount of exhaust gas introduced into the crank chamber 10Z via the first communication passage 51A and the second communication passage 52A can be further increased.
[0065] For example, the turbocharger 47 may be omitted. In this case, the first end of the communication passage may be connected, for example, to the middle of the exhaust pipe 42. The second end of the communication passage may be connected to the crank chamber 10Z. Furthermore, the control valve may be located, for example, in the middle of the communication passage.
[0066] For example, the configuration of the control device 90 may be changed. Specifically, the control device 90 may be configured as a circuit including one or more processors that execute various processes according to a computer program (software). The control device 90 may also be configured as a circuit including one or more dedicated hardware circuits, such as an application-specific integrated circuit (ASIC), that execute at least some of the various processes, or a combination thereof. The processor includes a CPU and memory such as RAM and ROM. The memory stores program code or instructions configured to cause the CPU to execute processes. The memory, i.e., computer-readable medium, includes any medium accessible by a general-purpose or dedicated computer. [Explanation of symbols]
[0067] 10...Internal combustion engine 10A...Intake passage 10B...Exhaust passage 10C...Combustion chamber 10Z...Crankcase 21...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 pipe 42...Exhaust pipe 46...Air cleaner 47...Turbocharger 47A...Compressor wheel 47B...Connecting shaft 47C...Turbine wheel 47HA...Compressor housing 47HB...Bearing housing 47HC...Turbine housing 47N...Variable nozzle device 48...Intercooler 51A...First communication passage 51V...First control valve 52A...Second communication passage 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...Strainer 82...Suction pipe 83...Oil pump 86...Accelerator operation amount sensor 87...Vehicle speed sensor 88...Crank angle sensor 89...Oil temperature sensor 90...Control device 91...Execution device 92...Storage device 92A...Control program 100...Vehicle
Claims
1. a cylinder for burning hydrogen as fuel; an intake passage that introduces intake air into the cylinder; an exhaust passage for discharging exhaust gas from the cylinder; a crank chamber that accommodates the crankshaft and stores oil; a communication passage that introduces a portion of the exhaust gas that has flowed through the exhaust passage into the crank chamber; a control valve that opens and closes the flow path of the communication passage; The invention relates to an internal combustion engine having acquiring an oil temperature that is a temperature of oil stored in the crank chamber; determining whether the acquired oil temperature is equal to or lower than a predetermined temperature; When it is determined that the oil temperature is equal to or lower than the specified temperature, the opening degree of the control valve is increased compared to when it is determined that the oil temperature is higher than the specified temperature; Run Control device for internal combustion engines.
2. the internal combustion engine includes a turbocharger that utilizes the flow of exhaust gas through the exhaust passage to compress intake air flowing through the intake passage and supply the compressed intake air downstream, The turbocharger is a compressor housing that constitutes a part of the intake passage; a turbine housing that constitutes a part of the exhaust passage; a bearing housing connecting the compressor housing and the turbine housing; a compressor wheel located inside the compressor housing; a turbine wheel located within the turbine housing; a connecting shaft located inside the bearing housing and connecting the compressor wheel and the turbine wheel, The communication passage is connected to an internal space of the bearing housing in which the connecting shaft is located. The control device for an internal combustion engine according to claim 1.
3. the internal combustion engine includes a turbocharger that utilizes the flow of exhaust gas through the exhaust passage to compress intake air flowing through the intake passage and supply the compressed intake air downstream, The turbocharger is a compressor housing that constitutes a part of the intake passage; a turbine housing that constitutes a part of the exhaust passage; a bearing housing connecting the compressor housing and the turbine housing; a compressor wheel located inside the compressor housing; a turbine wheel located within the turbine housing; a connecting shaft located inside the bearing housing and connecting the compressor wheel and the turbine wheel, The communication passage is connected to a portion of the exhaust passage upstream of the turbine wheel. The control device for an internal combustion engine according to claim 1.
4. the turbocharger is provided with a variable nozzle device that is located inside the turbine housing and adjusts the size of a gas flow path that is a flow path of exhaust gas leading to the turbine wheel, When it is determined that the oil temperature is equal to or lower than the specified temperature, the opening of the control valve is increased and the gas flow path is narrowed by the variable nozzle device compared to when it is determined that the oil temperature is higher than the specified temperature. Run 4. The control device for an internal combustion engine according to claim 2 or 3.
5. The turbine housing includes a main passage in which the turbine wheel is located and a bypass passage that bypasses the turbine wheel, the turbocharger includes a wastegate valve that opens and closes a flow path of the bypass passage, When it is determined that the oil temperature is equal to or lower than the specified temperature, the opening degree of the control valve is increased and the opening degree of the wastegate valve is decreased compared to when it is determined that the oil temperature is higher than the specified temperature; Run 4. The control device for an internal combustion engine according to claim 2 or 3.
Citation Information
Patent Citations
Four-stroke engine and method for preventing ignition inside crankcase
JP2021127704A