Internal combustion engine and internal combustion engine system

Abstract

The present application relates to an internal combustion engine and an internal combustion engine system. The internal combustion engine has an oil pump, an oil filter, a supply flow path, a return flow path, a soot separation portion, and a pressure relief valve. The oil pump ejects oil. The oil filter filters the oil ejected from the oil pump. The supply flow path is provided so as to extend from the oil pump through the oil filter. The return flow path branches from the supply flow path. The soot separation portion traps soot contained in the oil in the return flow path. The pressure relief valve is disposed in the return flow path, and, by opening, causes the oil that is branched to the return flow path to flow through the soot separation portion.

Description

Technical Field

[0001] This invention relates to an internal combustion engine and an internal combustion engine system. Background Technology

[0002] In an internal combustion engine, engine oil is supplied as lubricant to a component including fuel injectors. In an internal combustion engine, engine oil injected from a fuel pump passes through a supply flow path to the component. Furthermore, a known internal combustion engine structure includes a return flow path that allows engine oil to flow back from the injection side of the fuel pump to the suction side, and a pressure relief valve is installed in the return flow path (see Japanese Patent Application Publication No. 2012-31781). In this type of internal combustion engine, by opening the pressure relief valve, engine oil flows from the injection side of the fuel pump to the suction side in the return flow path, releasing the pressure of the engine oil on the injection side of the fuel pump.

[0003] Here, for internal combustion engines, the aim is to suppress the increase in oil pressure at the injection side (injection port) of the oil pump by using a pressure relief valve or similar device, thereby reducing the driving force of the oil pump. Additionally, the aim is to properly remove carbon soot from the oil by using a carbon soot separation unit such as a centrifugal separator. Summary of the Invention

[0004] The problem to be solved by the present invention is to provide an internal combustion engine and an internal combustion engine system that can suppress the increase of oil pressure on the injection side of the oil pump and can properly remove carbon soot from the oil.

[0005] In one embodiment of the invention, an internal combustion engine includes an oil pump, an oil filter, a supply flow path, a return flow path, a soot separator, and a pressure relief valve. The oil pump sprays engine oil, and the oil filter filters the oil sprayed from the oil pump. The supply flow path extends from the oil pump through the oil filter, and the return flow path branches off from the supply flow path. The soot separator captures soot contained in the engine oil in the return flow path. The pressure relief valve is located in the return flow path, and when opened, allows engine oil diverted to the return flow path to flow through the soot separator.

[0006] According to the present invention, an internal combustion engine and an internal combustion engine system are provided that can suppress the increase in oil pressure on the injection side of the oil pump and can properly remove soot from the oil. Attached Figure Description

[0007] Figure 1 This is a schematic diagram illustrating an example of an internal combustion engine system involved in the implementation.

[0008] Figure 2 This is a schematic diagram illustrating an example of an oil system (lubricating oil system) that supplies oil to a target in an internal combustion engine according to the embodiment.

[0009] Figure 3This is a flowchart that schematically illustrates an example of the motion control of an internal combustion engine performed by a controller in an implementation.

[0010] Figure 4 This is a schematic diagram illustrating an example of an oil system (lubricating oil system) that supplies oil to an object in an internal combustion engine in a certain variation.

[0011] Figure 5 This is to explain in relation to Figure 4 A schematic diagram of an example of an oil system (lubricating oil system) that supplies oil to an object in an internal combustion engine in a different variation. Detailed Implementation

[0012] Hereinafter, the embodiments will be described with reference to the accompanying drawings.

[0013] Figure 1 This is a schematic diagram illustrating an example of an internal combustion engine system 1 according to an embodiment. The internal combustion engine system 1 includes an internal combustion engine 2 and a controller 3. The internal combustion engine 2 and the controller 3 are mounted on an internal combustion engine mounting device. Examples of internal combustion engine mounting devices that include the internal combustion engine 2 and the controller 3 include vehicles, stationary generators, industrial machinery, and power source devices. The internal combustion engine 2 is, for example, a diesel engine, but it can also be a gasoline engine. In the internal combustion engine 2, power is generated by burning fuels such as diesel or gasoline.

[0014] The controller 3 comprises a computer installed in the internal combustion engine, such as an onboard computer. The computer constituting the controller 3 includes a processor or integrated circuit and a storage medium. The processor or integrated circuit in the controller 3 includes any of the following: ECU (Electronic Control Unit), CPU (Central Processing Unit), ASIC (Application Specific Integrated Circuit), microcomputer, FPGA (Field Programmable Gate Array), and DSP (Digital Signal Processor). The controller 3 may have only one processor or multiple processors. Furthermore, the controller 3 serves as a storage medium, including either a main storage medium or an auxiliary storage medium. The controller 3 controls the operation of the internal combustion engine 2 by executing a program stored in the storage medium.

[0015] In internal combustion engine 2, engine oil (engine oil) is supplied to the target as a lubricant. Furthermore, in... Figure 1 In the diagram, solid arrows indicate the flow of engine oil in internal combustion engine 2. Additionally, in... Figure 1 In the diagram, the dashed arrows represent the controller 3's control over the actions.

[0016] Figure 2 This is a schematic diagram illustrating an example of an oil system (lubricating oil system) that supplies oil to the target in the internal combustion engine 2 according to the embodiment. Figure 1 and Figure 2 As shown, the internal combustion engine 2 includes an oil pan 5, an oil pump 6, an oil filter 7, and an oil cooler 8. The oil pan 5 has an oil reservoir 11 for storing engine oil. The internal combustion engine 2 also has a suction flow path 12 that extends from the oil reservoir 11 in the oil pan 5 to the oil pump 6. The oil pump 6 draws up the engine oil stored in the oil reservoir 11 in the oil pan 5 by operating. The drawn-up oil flows into the oil pump 6 through the suction flow path 12. Furthermore, the oil pump 6 sprays out the drawn-up oil. Therefore, the oil sprayed by the oil pump 6 accumulates in the oil pan 5.

[0017] The internal combustion engine 2 has a supply flow path (main supply flow path) 13 and an oil passage (main oil passage) 15. The supply flow path 13 extends from the oil pump 6 to the oil passage 15 in a manner that passes sequentially through the oil filter 7 and the oil cooler 8. In the supply flow path 13, the oil filter 7 is positioned upstream of the oil cooler 8. The oil pump 6 sprays oil into the supply flow path 13. In the internal combustion engine 2, the oil sprayed from the oil pump 6 is supplied to the oil passage 15 through the supply flow path 13.

[0018] In the supply flow path 13, the oil filter 7 filters the oil sprayed from the oil pump 6. The oil filter 7 has a filter element 16 as the filter material. Through filtration in the oil filter 7, impurities such as wear particles and dust are removed from the oil. However, the amount of carbon soot contained in the oil is trace. Therefore, through filtration in the oil filter 7, carbon soot cannot be removed from the oil, or can hardly be removed. The oil cooler 8 cools the oil. Therefore, in the supply flow path 13, the oil temperature is lower in the region downstream of the oil cooler 8 compared to the region upstream of the oil cooler 8.

[0019] The internal combustion engine 2 has a cylinder block 17 and a cylinder head 18. In the internal combustion engine 2, the outer casing is formed by the oil pan 5, cylinder block 17, and cylinder head 18. The cylinder block 17 has cylinders and a crankcase. An oil pump 6 and the like are disposed inside the cylinder block 17. Furthermore, in the internal combustion engine 2, the oil reservoir 11 of the oil pan 5 is formed inside the outer casing. The cylinder block 17 has an outer surface (outer wall surface) 21 exposed to the outside of the internal combustion engine 2. In the internal combustion engine 2, the outer surface 21 of the cylinder block 17 forms part of the outer casing. An oil filter 7 and an oil cooler 8 are disposed on the outer surface 21 of the cylinder block 17 and exposed to the outside of the internal combustion engine 2. Furthermore, in… Figure 2In the middle, it roughly represents the wall that separates the exterior and interior of the internal combustion engine 2 in the oil pan 5, cylinder block 17 and cylinder head 18.

[0020] In the internal combustion engine 2, engine oil supplied to the oil passage 15 via the supply flow path 13 is supplied to each of the oil injectors. Each oil injector is lubricated by the supplied oil. Furthermore, the oil supplied to each oil injector returns to the oil reservoir 11 in the oil pan 5. The internal combustion engine 2 includes a fuel injector 22 as one of the oil injectors. The fuel injector 22 is disposed inside the cylinder block 17. The internal combustion engine 2 has a secondary supply flow path 23, which extends from the oil passage 15 to the fuel injector 22. In the internal combustion engine 2, engine oil is supplied to the fuel injector 22 from the oil passage 15 via the secondary supply flow path 23. Therefore, the engine oil injected from the oil pump 6 is supplied to the fuel injector 22 in sequence via the supply flow path 13, the oil passage 15, and the secondary supply flow path 23.

[0021] The internal combustion engine 2 includes a piston 25 and a crankshaft 26. The piston 25 and crankshaft 26 are disposed inside the cylinder block 17. In the internal combustion engine 2, the piston 25 reciprocates due to fuel combustion, thereby rotating the crankshaft 26. Furthermore, the power generated by the rotational motion of the crankshaft 26 is transmitted from the internal combustion engine 2 to the drive unit of the internal combustion engine-mounted equipment. In the internal combustion engine 2, a fuel injector 22 sprays supplied engine oil toward the reciprocating piston 25. The piston 25 is cooled by the engine oil sprayed from the fuel injector 22. In addition to the fuel injector 22, the internal combustion engine 2 also includes a valve mechanism (not shown) in the cylinder head 18, journals of the crankshaft 26 (not shown), a turbocharger (not shown), etc., as the source of engine oil.

[0022] The internal combustion engine 2 includes an oil check valve 27. The oil check valve 27 is disposed in the secondary supply flow path 23 between the oil passage 15 and the fuel injector 22. The oil check valve 27 is, for example, an on / off valve or a proportional valve. Alternatively, the oil check valve 27 may be, for example, a solenoid valve whose open / closed state changes according to the power supply status. By opening the oil check valve 27, oil can be supplied to the fuel injector 22, and oil is injected from the fuel injector 22 into the piston 25. Furthermore, when the oil check valve 27 is closed, no oil is supplied to the fuel injector 22. Additionally, when the oil check valve 27 is a proportional valve, the amount of oil supplied to the fuel injector 22 changes corresponding to the opening degree of the oil check valve 27, and the amount of oil injected from the fuel injector 22 changes.

[0023] The internal combustion engine 2 has a return oil flow path 31 branching off from the supply flow path 13. The return oil flow path 31 branches off from the supply flow path 13 on the upstream side relative to the oil cooler 8. For example... Figure 1 and Figure 2As shown, in the internal combustion engine 2, a return oil flow path 31 branches off from the supply flow path 13 between the oil pump 6 and the oil filter 7. Furthermore, the internal combustion engine 2 includes a soot separator 32 and a pressure relief valve 33. The soot separator 32 and the pressure relief valve 33 are disposed in the return oil flow path 31. The return oil flow path 31 extends sequentially from its connection point with the supply flow path 13 (the branch point from the supply flow path 13) through the pressure relief valve 33 and the soot separator 32. Therefore, the pressure relief valve 33 is disposed between the branch point of the return oil flow path 31 and the soot separator 32.

[0024] The soot separation unit 32 is composed of a centrifugal separator. The soot separation unit 32 has a centrifugal rotor 35 and a collecting material 36 as a filter material. In the soot separation unit 32, the centrifugal rotor 35 rotates, thereby centrifugally separating soot from the engine oil. Furthermore, the centrifugally separated soot is captured by the collecting material 36. Therefore, in the internal combustion engine 2, the soot separation unit 32 captures soot contained in the engine oil in the oil return path 31. Thus, the soot contained in the engine oil is removed by the soot separation unit 32.

[0025] In the return oil flow path 31, a pressure relief valve 33 is disposed between the connection point to the supply flow path 13 and the soot separator 32. The pressure relief valve 33 is, for example, an on / off valve or a proportional valve. Alternatively, the pressure relief valve 33 may be, for example, a solenoid valve whose open / closed state varies depending on the power supply status. By opening the pressure relief valve 33, the oil diverted from the supply flow path 13 to the return oil flow path 31 flows toward the soot separator 32, supplying oil to the soot separator 32. Furthermore, by opening the pressure relief valve 33, the oil pressure at the injection side (injection port) of the oil pump 6 is released, and the oil pressure in the supply flow path 13 is also released. When the pressure relief valve 33 is closed, no oil is supplied to the soot separator 32. Additionally, when the pressure relief valve 33 is a proportional valve, the amount of oil supplied to the soot separator 32 changes accordingly with the opening degree of the pressure relief valve 33. Therefore, by opening the pressure relief valve 33, the oil diverted to the return oil flow path 31 flows through the carbon soot separator 32.

[0026] In the internal combustion engine 2, the soot separator 32 and the pressure relief valve 33 are disposed on the outer surface (outer wall surface) 21 of the cylinder block 17. Therefore, the soot separator 32 and the pressure relief valve 33 are exposed outside the internal combustion engine 2. In addition, in the oil return path 31, the end opposite to the connection position to the supply path 13 (the branch position of the supply path 13) is not connected to the intake path 12, nor is it connected to the intake side of the oil pump 6. Moreover, the end of the oil return path 31 opposite to the connection position to the supply path 13 is connected to the oil storage section 11 of the oil pan 5. Therefore, the oil that has captured soot is discharged from the soot separator 32 through the oil return path 31 to the oil storage section 11 of the oil pan 5. Due to this structure, the oil return path 31 is different from the oil return path that returns oil from the spray side to the intake side of the oil pump 6. Furthermore, the pressure relief valve 33 is provided separately from the oil pump 6.

[0027] In the internal combustion engine system 1, the controller 3 controls the operation of the oil check valve 27 and the pressure relief valve 33. For example, if the oil check valve 27 is a solenoid valve, the controller 3 controls the supply of electricity to the oil check valve 27, thereby controlling the energization state of the oil check valve 27 and its opening and closing state. Similarly, if the pressure relief valve 33 is a solenoid valve, the controller 3 controls the supply of electricity to the pressure relief valve 33, thereby controlling the energization state of the pressure relief valve 33 and its opening and closing state.

[0028] The controller 3 estimates the temperature of the piston 25 and controls the operation of the oil check valve 27 based on the estimated temperature of the piston 25. Therefore, based on the estimated temperature of the piston 25, the controller controls the opening and closing state of the oil check valve 27, controlling the supply of oil to the fuel injector 22. While the internal combustion engine 2 is operating, the controller 3 repeatedly estimates the temperature of the piston 25 over a specified period. The controller 3 estimates the temperature of the piston 25 based on the rotational speed of the crankshaft 26 and the amount of oil injected from the fuel injector 22 during a specified time period.

[0029] The internal combustion engine 2 has an angle sensor (not shown) that detects the crankshaft angle of the crankshaft 26. Based on the angle sensor's detection results, the controller 3 calculates the time change of the crankshaft angle and the rotational speed of the crankshaft 26. Additionally, based on the time change of the opening and closing state of the oil check valve 27, the controller 3 calculates the amount of oil injected from the fuel injector 22 during a specified time period. The controller 3 stores relationship data, such as data relating the piston 25 temperature to the crankshaft 26 rotational speed, fuel injection amount, and oil injection amount from the fuel injector 22, in a storage medium. This relationship data may be, for example, a data table that establishes a correlation between the piston 25 temperature and the crankshaft 26 rotational speed, fuel injection amount, and oil injection amount from the fuel injector 22. The controller 3 calculates the piston 25 temperature based on the calculated rotational speed of the crankshaft 26, the calculated amount of oil injected from the fuel injector 22 during the specified time period, and the relationship data.

[0030] In the internal combustion engine system 1, the controller 3 controls the operation of the pressure relief valve 33 in accordance with the opening and closing state of the oil check valve 27. Therefore, in the internal combustion engine 2, the operation of the pressure relief valve 33 is controlled in accordance with the oil supply state to the fuel injector 22, thereby controlling the flow of oil from the return oil path 31 to the soot separator 32. In other words, in the internal combustion engine 2, the operation of the pressure relief valve 33 is controlled in accordance with the oil supply state to the fuel injector 22, thereby controlling the flow of oil from the soot separator 32 in the return oil path 31.

[0031] Figure 3 This is a flowchart that schematically illustrates an example of the motion control of the internal combustion engine 2 via the controller 3 in the embodiment. Figure 3 The motion control is performed repeatedly over time while the internal combustion engine 2 is in operation. If it starts... Figure 3 In the process of processing, the controller 3 estimates the temperature of the piston 25 (S101). The estimation of the temperature of the piston 25 is performed as described above. Furthermore, the controller 3 determines whether the estimated temperature of the piston 25 is below the reference temperature (S102).

[0032] If the estimated temperature is higher than the reference temperature (S102-No), the controller 3 opens or keeps the oil check valve 27 open (S103). This supplies oil to or maintains the supply of oil to the fuel injector 22. Furthermore, the controller 3 closes or keeps the pressure relief valve 33 closed (S104). This stops or maintains the cessation of oil supply to the soot separator 32.

[0033] On the other hand, if the estimated temperature is below the reference temperature (S102 - Yes), the controller 3 closes or maintains the oil check valve 27 in a closed state (S105). This stops or maintains the supply of oil to the fuel injector 22. Furthermore, the controller 3 opens or maintains the pressure relief valve 33 in an open state (S106). This supplies or maintains the supply of oil to the soot separator 32. Moreover, the pressure of the oil in the supply path 13 is released or maintained in a state where the oil pressure is released.

[0034] In the aforementioned embodiments, the supply flow path 13 extends from the oil pump 6 through the oil filter 7, and a return flow path 31 branches off from the supply flow path 13. Furthermore, by opening the pressure relief valve 33 located between the branch point of the return flow path 31 and the soot separator 32, the oil diverted from the supply flow path 13 to the return flow path 31 flows through the soot separator 32. Therefore, even if the pressure on the injection side of the oil pump 6 increases, the pressure of the oil in the supply flow path 13 (the injection side of the oil pump 6) is released by opening the pressure relief valve 33. Thus, the increase in oil pressure on the injection side of the oil pump 6 can be suppressed. By suppressing the increase in oil pressure on the injection side (injection port) of the oil pump 6, the driving force of the oil pump 6 can be reduced. Moreover, by reducing the driving force of the oil pump 6, the fuel consumption in the internal combustion engine 2 can be reduced.

[0035] Furthermore, by opening the pressure relief valve 33, engine oil flows through the carbon soot separator 32, thus allowing carbon soot to be properly removed from the engine oil while the internal combustion engine 2 is operating. By properly removing carbon soot from the engine oil, the concentration of carbon soot in the engine oil supplied as lubricant to the sliding parts of the internal combustion engine 2 is kept low. This reduces wear on the sliding parts and extends the lifespan of the internal combustion engine 2.

[0036] Furthermore, in the internal combustion engine 2, the oil supply ratio to the fuel injector 22 is higher than the oil supply ratio to other components. In this embodiment, the controller 3 controls the operation of the pressure relief valve 33 in accordance with the oil supply status to the fuel injector 22, controlling the flow of oil passing through the soot separator 32 in the return oil path 31. By performing this control, the pressure relief valve 33 is opened when the oil supply to the fuel injector 22 stops, releasing the pressure of the oil in the supply path 13. Therefore, when the oil supply to the fuel injector 22 stops, the increase in oil pressure on the injection side (injection outlet) of the oil pump 6 is appropriately suppressed. Thus, the driving force of the oil pump 6 is further reduced.

[0037] Furthermore, by performing the aforementioned control, oil is supplied to the soot separator 32 at the precise time when oil injection from the injector 22 ceases. Therefore, soot is properly removed from the oil without affecting the operation of the injector 22.

[0038] Furthermore, in the implementation method, the controller 3 stops the supply of oil to the fuel injector 22 based on the estimated temperature of the piston 25 being below a reference temperature, thus stopping the injection of oil from the fuel injector 22 to the piston 25. This suppresses excessive temperature drops in the piston 25 due to oil from the fuel injector 22, and minimizes temperature fluctuations in the piston 25. Consequently, a longer lifespan for the piston 25 can be achieved.

[0039] Furthermore, by suppressing excessive temperature drop in piston 25, the contraction of the piston rings mounted on piston 25 is suppressed, and the significant expansion of the piston ring gap is prevented. Therefore, the flow rate of blow-by mixture flowing to the bottom side of the piston through the piston ring gap can be reduced. Additionally, by suppressing excessive temperature drop in piston 25, the temperature drop of the exhaust gas from internal combustion engine 2 is suppressed. As a result, the efficiency of the exhaust gas aftertreatment device and the turbocharger is improved.

[0040] Furthermore, in the embodiments, the carbon soot separator 32 and the pressure relief valve 33 are disposed on the outer surface (outer wall surface) 21 of the cylinder block 17, exposed to the outside of the internal combustion engine 2. Therefore, a structure in which the carbon soot separator 32 and the pressure relief valve 33 are disposed in the return oil flow path 31 can be realized without making significant changes to the structure that has never been provided with the carbon soot separator 32, etc. In addition, by making the structure in which the pressure relief valve 33 is exposed to the outside of the internal combustion engine 2, the maintainability of the pressure relief valve 33 is improved. For example, it is easy to connect the power supply wiring to the pressure relief valve 33 and to repair the pressure relief valve 33 in case of failure. In addition, since the carbon soot separator 32 and the pressure relief valve 33 are disposed in the cylinder block 17, the strength at the location where the carbon soot separator 32 and the pressure relief valve 33 are disposed is adequately ensured.

[0041] Furthermore, in the return oil flow path 31, the end opposite to the connection position to the supply flow path 13 is connected to the oil storage section 11 of the oil pan 5, and oil is discharged from the soot separator 32 to the oil pan 5 through the return oil flow path 31. Therefore, the return oil flow path 31 is not connected to the suction side (suction flow path 12) of the oil pump 6. Due to this structure, even if the soot separator 32 and the pressure relief valve 33 are arranged on the outer surface 21 of the cylinder block 17, the return oil flow path 31 extending through the soot separator 32 and the pressure relief valve 33 can be formed with a simple structure.

[0042] Furthermore, in the embodiments, a return oil flow path 31 branches off from the supply flow path 13 on the upstream side relative to the oil cooler 8. Therefore, the flow of oil cooled by the oil cooler 8 into the soot separation section 32 is appropriately suppressed. Consequently, oil with a higher temperature is supplied to the soot separation section 32, and therefore oil with lower viscosity is also supplied to the soot separation section 32. Thus, soot is further and appropriately separated from the oil in the soot separation section 32, improving the soot collection efficiency.

[0043] In addition, Figure 2 In one example, a return flow path 31 branches off from the supply flow path 13 between the oil pump 6 and the oil filter 7. By configuring it in this way, compared to a configuration where the return flow path 31 branches off downstream of the oil filter 7, the pressure on the ejector side (ejector outlet) of the oil pump 6 decreases by at least the amount corresponding to the pressure loss in the oil filter 7. This further reduces the driving force of the oil pump 6.

[0044] Figure 4 This is a schematic diagram illustrating an example of an oil system (lubricating oil system) that supplies oil to an object in an internal combustion engine 2 involved in a certain modification. Figure 4 In general, this represents the wall that separates the exterior and interior of the internal combustion engine 2 within the oil pan 5, cylinder block 17, and cylinder head 18. For example... Figure 4 As shown, in this modified example, a return oil flow path 31 branches off from the supply flow path 13 on the downstream side relative to the oil filter 7. That is, the return oil flow path 31 branches off from the supply flow path 13 between the oil filter 7 and the oil cooler 8.

[0045] exist Figure 4 In the modified example, apart from the different branch positions of the oil return path 31, the oil system is the same as... Figure 2 This is an example of a structure with the same characteristics. Therefore, in this modified example, the same function and effect as in the aforementioned embodiments are achieved. Furthermore, in this modified example, a return oil flow path 31 branches off from the supply flow path 13 downstream of the oil filter 7, so the oil, with impurities removed by the oil filter 7, is supplied to the soot separation section 32. Therefore, soot is further and appropriately separated from the oil in the soot separation section 32, improving the soot collection efficiency.

[0046] Figure 5 This is to explain in relation to Figure 4 A schematic diagram of an example of an oil system (lubricating oil system) supplying oil to an internal combustion engine 2 in a different variant. Figure 5 In general, this represents the wall that separates the exterior and interior of the internal combustion engine 2 within the oil pan 5, cylinder block 17, and cylinder head 18. For example... Figure 5As shown, in this modified example, the internal combustion engine 2 has a removal device 40 that integrates the oil filter 7 and the soot separator 32. The removal device 40 is disposed on the outer surface 21 of the cylinder block 17. Therefore, in this modified example, the oil filter 7, the soot separator 32, and the pressure relief valve 33 are also disposed on the outer surface of the cylinder block 17.

[0047] In the removal device 40, the portion that functions as the oil filter 7 is isolated from the portion that functions as the soot separator 32. Furthermore, in the removal device 40, the supply flow path 13 passes through the portion that functions as the oil filter 7, and the return flow path 31 passes through the portion that functions as the soot separator 32. In the removal device 40, the portion through which the supply flow path 13 passes and the portion through which the return flow path 31 passes are not connected. Due to this structure, in the removal device 40, which integrates the oil filter 7 and the soot separator 32, the inflow of oil from the supply flow path 13 to the return flow path 31 and the inflow of oil from the return flow path 31 to the supply flow path 13 are suppressed.

[0048] exist Figure 5 In the modified example, except that the oil filter 7 and the carbon soot separator 32 are integrated, the oil system becomes... Figure 2 This is an example of a structure with the same characteristics as the aforementioned embodiments. Therefore, in this modified example, the same functions and effects as in the aforementioned embodiments are achieved. Furthermore, in this modified example, the oil filter 7 and the soot separator 32 are integrated, making it easy to mount the oil filter 7 and the soot separator 32 onto the internal combustion engine 2. Additionally, it facilitates the replacement of the filter element 16 and the collecting material 36, improving the maintainability of the oil filter 7 and the soot separator 32.

[0049] Furthermore, in a certain variation, with Figure 4 Similar in structure, a return oil flow path 31 branches off from the supply flow path 13 between the oil filter 7 and the oil cooler 8. Furthermore, with... Figure 5 Similarly, the internal combustion engine 2 has a removal device 40 that integrates the oil filter 7 and the soot separator 32. In this modified example, the same functions and effects as in the aforementioned embodiments are achieved.

[0050] Furthermore, in the aforementioned embodiment, the pressure relief valve 33 is disposed between the branch position of the return oil flow path 31 and the soot separator 32, but this is not a limitation. In a certain modification, the pressure relief valve 33 is disposed in the return oil flow path 31 between the soot separator 32 and the oil reservoir 11 of the oil pan 5. In this case, the soot separator 32 is disposed between the branch position of the return oil flow path 31 and the pressure relief valve 33. In this modification, by opening the pressure relief valve 33 disposed in the return oil flow path 31, the oil diverted from the supply flow path 13 to the return oil flow path 31 flows through the soot separator 32. Therefore, in this modification, the same function and effect as in the aforementioned embodiment are also achieved.

[0051] Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be made during implementation without departing from its spirit. Additionally, the embodiments can be appropriately combined, resulting in combined effects. Moreover, the above embodiments include various inventions, and various inventions can be extracted through combinations selected from the disclosed multiple structural elements. For example, even if several structural elements are deleted from all the constituent elements shown in the embodiments, if the problem is solved and the desired effect is obtained, the structure after deleting those structural elements can still be extracted as an invention.

Claims

1. An internal combustion engine, comprising: The oil pump sprays out engine oil; An oil filter that filters the oil sprayed from the oil pump; A supply flow path extends from the oil pump through the oil filter; The return oil flow path branches off from the supply flow path; The carbon soot separation section captures the carbon soot contained in the engine oil in the oil return path; as well as A pressure relief valve is disposed in the oil return path, and by opening, the oil diverted to the oil return path flows through the soot separator.

2. The internal combustion engine according to claim 1, wherein, It also has: Fuel injectors, which are capable of spraying the engine oil supplied through the supply flow path; and The piston is cooled by the oil sprayed from the fuel injector. The pressure relief valve is controlled in accordance with the oil supply status to the fuel injector, thereby controlling the flow of oil from the return oil path to the soot separator.

3. The internal combustion engine according to claim 1, wherein, It also has a cylinder block having an outer surface that forms part of the outer casing, and the soot separator and the pressure relief valve are disposed on the outer surface.

4. The internal combustion engine according to claim 1, wherein, It also has an oil pan that stores the engine oil sprayed by the oil pump, and the engine oil is discharged to the oil pan through the return oil path.

5. The internal combustion engine according to claim 1, wherein, It also includes an oil cooler, which is disposed downstream of the oil filter in the supply flow path and cools the oil flowing in the supply flow path. The return oil path branches off from the supply path on the upstream side relative to the oil cooler.

6. An internal combustion engine system, comprising: The internal combustion engine according to any one of claims 1 to 5; and The controller controls the operation of the pressure relief valve.

7. The internal combustion engine system according to claim 6, wherein, The internal combustion engine also has: Fuel injectors, which are capable of spraying the engine oil supplied through the supply flow path; and The piston is cooled by the oil sprayed from the fuel injector. The controller controls the supply of engine oil to the fuel injector based on the temperature of the piston, and controls the operation of the pressure relief valve in accordance with the state of the oil supply to the fuel injector, thereby controlling the flow of engine oil from the return oil path to the soot separator.

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