Internal combustion engines and internal combustion engine systems

Abstract

To provide an internal combustion engine that can suppress the increase in oil pressure on the discharge side of the pump and can properly remove soot from the oil. [Solution] The internal combustion engine comprises a pump, an oil filter, a supply passage, a return passage, a soot separator, and a relief valve. The pump discharges oil, and the oil filter filters the oil discharged from the pump. The supply passage extends from the pump through the oil filter, and the return passage branches off from the supply passage. The soot separator collects soot contained in the oil in the return passage. The relief valve is located in the return passage and, when opened, allows the oil diverted to the return passage to flow through the soot separator.

Description

Technical Field

[0001] The present invention relates to an internal combustion engine and an internal combustion engine system.

Background Art

[0002] In an internal combustion engine, oil (engine oil) is supplied as lubricating oil or the like to a supply target including an oil jet. In an internal combustion engine, the oil discharged from a pump is supplied to the supply target through a supply flow path. Further, as an internal combustion engine, there is known an internal combustion engine provided with a return flow path for returning oil from the discharge side of the pump to the suction side, and a relief valve is arranged in the return flow path (see Patent Document 1). In such an internal combustion engine, when the relief valve opens, oil flows from the discharge side to the suction side of the pump in the return flow path, and the pressure of the oil at the discharge side of the pump is released.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, in an internal combustion engine, it is required to suppress an increase in the pressure of oil at the discharge side (discharge port) of the pump by using a relief valve or the like and reduce the driving force of the pump. Further, it is required to appropriately remove sludge from the oil by using a sludge separation part such as a centrifugal separator.

[0005] The problem to be solved by the present invention is to provide an internal combustion engine and an internal combustion engine system capable of suppressing an increase in the pressure of oil at the discharge side of the pump and appropriately removing sludge from the oil.

Means for Solving the Problems

[0006] In one embodiment of the present invention, the internal combustion engine comprises a pump, an oil filter, a supply passage, a return passage, a soot separator, and a relief valve. The pump discharges oil, and the oil filter filters the oil discharged from the pump. The supply passage extends from the pump through the oil filter, and the return passage branches off from the supply passage. The soot separator collects soot contained in the oil in the return passage. The relief valve is located in the return passage and, when opened, allows the oil diverted to the return passage to flow through the soot separator. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an internal combustion engine and an internal combustion engine system that can suppress the increase in oil pressure on the discharge side of the pump and can properly remove soot from the oil. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram showing an example of an internal combustion engine system according to an embodiment. [Figure 2] Figure 2 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 an embodiment. [Figure 3] Figure 3 is a flowchart illustrating an example of the operation control of an internal combustion engine performed by a controller in this embodiment. [Figure 4] Figure 4 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 a certain modification. [Figure 5] Figure 5 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, which is a different modification from that shown in Figure 4. [Modes for carrying out the invention]

[0009] The embodiments will be described below with reference to the drawings.

[0010] Figure 1 is a schematic diagram showing an example of an internal combustion engine system 1 according to an embodiment. The internal combustion engine system 1 comprises an internal combustion engine 2 and a controller 3. The internal combustion engine 2 and controller 3 are mounted on an internal combustion engine-equipped device. Examples of internal combustion engine-equipped devices on which the internal combustion engine 2 and controller 3 are mounted include vehicles, stationary generators, industrial machinery, and power source devices. The internal combustion engine 2 may be, for example, a diesel engine or a gasoline engine. Power is generated in the internal combustion engine 2 by burning fuel such as diesel oil or gasoline.

[0011] Controller 3 is composed of a computer installed in an internal combustion engine, such as an on-board computer. The computer comprising Controller 3 includes a processor or integrated circuit and a storage medium. In Controller 3, the processor or integrated circuit includes one of the following: ECU (Electronic Control Unit), CPU (Central Processing Unit), ASIC (Application Specific Integrated Circuit), microcontroller, FPGA (Field Programmable Gate Array), and DSP (Digital Signal Processor). Controller 3 may have only one processor or multiple processors. Furthermore, Controller 3 includes either a main storage medium including memory or an auxiliary storage medium as its storage medium. Controller 3 controls the operation of the internal combustion engine 2 by executing a program stored in the storage medium.

[0012] In the internal combustion engine 2, oil (engine oil) is supplied to the target as a lubricant, etc. In Figure 1, the flow of oil in the internal combustion engine 2 is shown by solid arrows. Also in Figure 1, the control of operation by the controller 3 is shown by dashed arrows.

[0013] Figure 2 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 2 according to an embodiment. As shown in Figures 1 and 2, the internal combustion engine 2 includes an oil pan 5, a pump 6, an oil filter 7, and an oil cooler 8. The oil pan 5 has an oil reservoir 11 in which oil is stored. The internal combustion engine 2 also has a suction passage 12, which extends from the oil reservoir 11 of the oil pan 5 to the pump 6. When the pump 6 operates, it pumps up the oil stored in the oil reservoir 11 of the oil pan 5. The pumped oil flows into the pump 6 through the suction passage 12. The pump 6 then discharges the pumped oil. Therefore, the oil discharged by the pump 6 is stored in the oil pan 5.

[0014] The internal combustion engine 2 has a supply passage (main supply passage) 13 and an oil gallery (main oil gallery) 15. The supply passage 13 extends from the pump 6 to the oil gallery 15, passing through the oil filter 7 and the oil cooler 8 in that order. In the supply passage 13, the oil filter 7 is positioned upstream of the oil cooler 8. The pump 6 discharges oil into the supply passage 13. In the internal combustion engine 2, the oil discharged from the pump 6 is supplied to the oil gallery 15 through the supply passage 13.

[0015] In the supply channel 13, the oil filter 7 filters the oil discharged from the pump 6. The oil filter 7 is equipped with a filter element 16 that serves as a filter medium. Through filtration by the oil filter 7, impurities such as wear particles and dust are removed from the oil. However, the soot contained in the oil is minute. Therefore, filtration by the oil filter 7 does not remove the soot from the oil, or removes very little of it. The oil cooler 8 cools the oil. Therefore, in the supply channel 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.

[0016] The internal combustion engine 2 comprises a cylinder block 17 and a cylinder head 18. In the internal combustion engine 2, the exterior is formed by the oil pan 5, cylinder block 17, cylinder head 18, etc. The cylinder block 17 comprises the cylinders and crankcase. The pump 6, etc., is located inside the cylinder block 17. In the internal combustion engine 2, the oil reservoir 11 of the oil pan 5 is formed inside the exterior portion. The cylinder block 17 has an outer surface (outer wall surface) 21 that is 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 exterior. The oil filter 7 and oil cooler 8 are located on the outer surface 21 of the cylinder block 17 and are exposed to the outside of the internal combustion engine 2. Note that in Figure 2, the wall portion separating the outside and inside of the internal combustion engine 2 in the oil pan 5, cylinder block 17, and cylinder head 18 is shown schematically.

[0017] In the internal combustion engine 2, oil supplied to the oil gallery 15 through the supply passage 13 is supplied to each of the target components. Each of the target components is lubricated by the supplied oil. The oil supplied to each of the target components is then returned to the oil reservoir 11 of the oil pan 5. The internal combustion engine 2 is equipped with an oil jet 22 as one of the target components of the oil supply. The oil jet 22 is located inside the cylinder block 17. The internal combustion engine 2 is equipped with a sub-supply passage 23, which extends from the oil gallery 15 to the oil jet 22. In the internal combustion engine 2, oil is supplied to the oil jet 22 from the oil gallery 15 through the sub-supply passage 23. Therefore, the oil discharged from the pump 6 is supplied to the oil jet 22 by passing through the supply passage 13, the oil gallery 15, and the sub-supply passage 23 in that order.

[0018] The internal combustion engine 2 includes a piston 25 and a crankshaft 26. The piston 25 and the crankshaft 26 are disposed inside the cylinder block 17. In the internal combustion engine 2, the piston 25 reciprocates due to combustion of fuel or the like, causing the crankshaft 26 to rotate. Then, the power generated by the rotational movement of the crankshaft 26 is transmitted from the internal combustion engine 2 to the drive unit of the equipment mounted on the internal combustion engine. In the internal combustion engine 2, the oil jet 22 can discharge the supplied oil toward the reciprocating piston 25. The piston 25 is cooled by the oil discharged from the oil jet 22. Further, the internal combustion engine 2 includes, as oil supply targets other than the oil jet 22, a valve operating mechanism (not shown) of the cylinder head 18, a journal portion (not shown) of the crankshaft 26, a turbocharger (not shown), and the like.

[0019] The internal combustion engine 2 includes an oil check valve 27. The oil check valve 27 is disposed between the oil gallery 15 and the oil jet 22 in the sub supply passage 23. The oil check valve 27 is, for example, an on-off valve or a proportional valve. Further, the oil check valve 27 is, for example, a solenoid valve whose opening / closing state changes in response to the power supply state. When the oil check valve 27 opens, oil is supplied to the oil jet 22, enabling the oil jet 22 to discharge oil to the piston 25. When the oil check valve 27 is closed, no oil is supplied to the oil jet 22. When the oil check valve 27 is a proportional valve, the amount of oil supplied to the oil jet 22 changes corresponding to the opening degree of the oil check valve 27, and the amount of oil discharged from the oil jet 22 changes.

[0020] The internal combustion engine 2 includes a return flow path 31 that branches off from the supply flow path 13. The return flow path 31 branches off from the supply flow path 13 upstream of the oil cooler 8. As shown in FIGS. 1 and 2, in the internal combustion engine 2, the return flow path 31 branches off from the supply flow path 13 between the pump 6 and the oil filter 7. Further, the internal combustion engine 2 includes a soot separation unit 32 and a relief valve 33. The soot separation unit 32 and the relief valve 33 are disposed in the return flow path 31. The return flow path 31 extends from the connection position (branch position from the supply flow path 13) to the supply flow path 13 through the relief valve 33 and the soot separation unit 32 in this order. For this reason, the relief valve 33 is disposed between the branch position of the return flow path 31 and the soot separation unit 32.

[0021] The soot separation unit 32 is composed of a centrifugal separator. The soot separation unit 32 includes a centrifugal rotor 35 and a collection material 36 that serves as a filter medium. In the soot separation unit 32, the centrifugal rotor 35 rotates, so that soot is centrifugally separated from the oil. Then, the centrifugally separated soot is collected by the collection material 36. Therefore, in the internal combustion engine 2, the soot separation unit 32 collects the soot contained in the oil in the return flow path 31. As a result, the soot contained in the oil is removed by the soot separation unit 32.

[0022] In the return flow path 31, the relief valve 33 is positioned between the connection point to the supply flow path 13 and the soot separation section 32. The relief valve 33 is, for example, an on / off valve or a proportional valve. Alternatively, the relief valve 33 is, for example, a solenoid valve whose open / closed state changes in response to the power supply state. When the relief valve 33 opens, the oil that has been diverted from the supply flow path 13 to the return flow path 31 flows toward the soot separation section 32, and oil is supplied to the soot separation section 32. Also, when the relief valve 33 opens, the oil pressure at the discharge side (discharge port) of the pump 6 is released, and the oil pressure in the supply flow path 13 is released. When the relief valve 33 is closed, no oil is supplied to the soot separation section 32. Furthermore, if the relief valve 33 is a proportional valve, the amount of oil supplied to the soot separation section 32 changes in response to the degree of opening of the relief valve 33. Therefore, when the relief valve 33 opens, the oil that was diverted to the return passage 31 flows through the soot separation section 32.

[0023] In the internal combustion engine 2, the soot separator 32 and the relief valve 33 are located on the outer surface (outer wall surface) 21 of the cylinder block 17. Therefore, the soot separator 32 and the relief valve 33 are exposed to the outside of the internal combustion engine 2. In the return passage 31, the end opposite to the connection point to the supply passage 13 (the branching point from the supply passage 13) is not connected to the suction passage 12 and is not connected to the suction side of the pump 6. In the return passage 31, the end opposite to the connection point to the supply passage 13 is in communication with the oil reservoir 11 of the oil pan 5. Therefore, the oil from which soot has been collected is discharged from the soot separator 32 through the return passage 31 to the oil reservoir 11 of the oil pan 5. Due to the above configuration, the return passage 31 is different from the return passage that returns oil from the discharge side to the suction side of the pump 6. The relief valve 33 is provided separately from the pump 6.

[0024] In the internal combustion engine system 1, the controller 3 controls the operation of the oil check valve 27 and the relief valve 33. For example, if the oil check valve 27 is a solenoid valve, the controller 3 controls the excitation state of the oil check valve 27 and thus controls the open / closed state of the oil check valve 27 by controlling the power supply to the oil check valve 27. Similarly, for example, if the relief valve 33 is a solenoid valve, the controller 3 controls the excitation state of the relief valve 33 and thus controls the open / closed state of the relief valve 33 by controlling the power supply to the relief valve 33.

[0025] 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, the open / closed state of the oil check valve 27 is controlled based on the estimated temperature of the piston 25, and the supply of oil to the oil jet 22 is controlled. When the internal combustion engine 2 is operating, the controller 3 repeatedly estimates the temperature of the piston 25 over time. 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 oil jet 22 over a predetermined period of time.

[0026] The internal combustion engine 2 is equipped with an angle sensor (not shown) that detects the crank angle of the crankshaft 26. Based on the detection result from the angle sensor, the controller 3 calculates the change in crank angle over time and calculates the rotational speed of the crankshaft 26. The controller 3 also calculates the amount of oil injected from the oil jet 22 over a predetermined period of time based on the change in the open / closed state of the oil check valve 27. The controller 3's storage medium stores relational data showing the relationship between the rotational speed of the crankshaft 26, the fuel injection amount, and the amount of oil injected from the oil jet 22 and the temperature of the piston 25. The relational data is, for example, a data table that associates the rotational speed of the crankshaft 26, the fuel injection amount, and the amount of oil injected from the oil jet 22 with the temperature of the piston 25. The controller 3 uses the calculation result for the rotational speed of the crankshaft 26, the calculation result for the amount of oil injected from the oil jet 22 over a predetermined period of time, and the relational data to calculate the temperature of the piston 25.

[0027] In the internal combustion engine system 1, the controller 3 controls the operation of the relief valve 33 in accordance with the open / closed state of the oil check valve 27. Therefore, in the internal combustion engine 2, the operation of the relief valve 33 is controlled in accordance with the oil supply state to the oil jet 22, thereby controlling the flow of oil through the return passage 31 to the soot separation section 32. In other words, in the internal combustion engine 2, the operation of the relief valve 33 is controlled in accordance with the oil supply state to the oil jet 22, thereby controlling the flow of oil through the soot separation section 32 in the return passage 31.

[0028] Figure 3 is a schematic flowchart illustrating an example of operation control of the internal combustion engine 2 performed by the controller 3 in this embodiment. The operation control in Figure 3 is performed repeatedly over time while the internal combustion engine 2 is operating. When the process in Figure 3 is started, the controller 3 estimates the temperature of the piston 25 (S101). The estimation of the piston 25 temperature is performed as described above. Then, the controller 3 determines whether the estimated temperature of the piston 25 is below the reference temperature (S102).

[0029] If the estimated temperature is higher than the reference temperature (S102-No), the controller 3 opens the oil check valve 27 or keeps it open (S103). This supplies oil to the oil jet 22 or maintains the state in which oil is supplied to the oil jet 22. The controller 3 then closes the relief valve 33 or maintains the state in which oil is supplied to the oil jet 22 (S104). This stops the supply of oil to the soot separator 32 or maintains the state in which the supply of oil to the soot separator 32 is stopped.

[0030] 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 the supply of oil to the oil jet 22 or maintains the state in which the supply of oil to the oil jet 22 is stopped. The controller 3 then opens or maintains the relief valve 33 in an open state (S106). This allows oil to be supplied to the soot separation unit 32 or maintains the state in which oil is supplied to the soot separation unit 32. In the supply passage 13, the oil pressure is released or maintains the state in which the oil pressure is released.

[0031] As described above, in the embodiment, the supply passage 13 extends from the pump 6 through the oil filter 7, and the return passage 31 branches off from the supply passage 13. When the relief valve 33, which is located between the branching point of the return passage 31 and the soot separation section 32, opens, the oil that has been diverted from the supply passage 13 to the return passage 31 flows through the soot separation section 32. Therefore, even if the pressure rises on the discharge side of the pump 6, opening the relief valve 33 releases the oil pressure in the supply passage 13 (discharge side of the pump 6). This makes it possible to suppress the increase in oil pressure on the discharge side of the pump 6. By suppressing the increase in oil pressure on the discharge side (discharge port) of the pump 6, the driving force of the pump 6 can be reduced. And by reducing the driving force of the pump 6, the amount of fuel consumed by the internal combustion engine 2 can be reduced.

[0032] Furthermore, by opening the relief valve 33, oil flows to the soot separation section 32, allowing the soot separation section 32 to properly remove soot from the oil while the internal combustion engine 2 is operating. Because soot is properly removed from the oil, the concentration of soot in the oil supplied as lubricant to the sliding parts of the internal combustion engine 2 is kept low. This reduces the amount of wear on the sliding parts and enables a longer lifespan for the internal combustion engine 2.

[0033] Furthermore, in the internal combustion engine 2, the proportion of oil supplied to the oil jet 22 is higher than the proportion of oil supplied to each of the other supply targets. In this embodiment, the controller 3 controls the operation of the relief valve 33 in accordance with the oil supply status to the oil jet 22, and controls the flow of oil through the soot separation section 32 in the return passage 31. With this control, when the oil supply to the oil jet 22 is stopped, the relief valve 33 opens and the oil pressure in the supply passage 13 is released. Therefore, when the oil supply to the oil jet 22 is stopped, the increase in oil pressure at the discharge side (discharge port) of the pump 6 is appropriately suppressed. As a result, the driving force of the pump 6 is further reduced.

[0034] Furthermore, with the control described above, oil is supplied to the soot separation unit 32 at the time when the oil injection from the oil jet 22 is stopped. As a result, soot is properly removed from the oil without affecting the operation of the oil jet 22.

[0035] Furthermore, in the embodiment, the controller 3 stops supplying oil to the oil jet 22 and stops injecting oil from the oil jet 22 to the piston 25 based on the estimated temperature of the piston 25 being below the reference temperature. This prevents the temperature of the piston 25 from dropping excessively due to the oil from the oil jet 22, and the temperature fluctuation range of the piston 25 is kept small. This makes it possible to extend the lifespan of the piston 25.

[0036] Furthermore, by suppressing an excessive drop in the temperature of the piston 25, the contraction of the piston rings attached to the piston 25 is suppressed, and the widening of the gap between the piston rings is suppressed. As a result, the flow rate of blow-by gas that flows to the bottom side of the piston through the gap between the piston rings can be reduced. In addition, by suppressing an excessive drop in the temperature of the piston 25, the drop in the temperature of the exhaust gas discharged from the internal combustion engine 2 is suppressed. This improves the efficiency of the exhaust gas aftertreatment device and turbocharger.

[0037] Furthermore, in the embodiments, the soot separator 32 and the relief valve 33 are arranged on the outer surface (outer wall surface) 21 of the cylinder block 17 and exposed to the outside of the internal combustion engine 2. Therefore, it is possible to realize a configuration in which the soot separator 32 and the relief valve 33 are arranged in the return passage 31 without making significant changes from a configuration in which the soot separator 32, etc., are not provided. In addition, by configuring the relief valve 33 to be exposed to the outside of the internal combustion engine 2, the maintainability of the relief valve 33 is improved. For example, it becomes possible to easily connect wiring for supplying power to the relief valve 33, and to repair the relief valve 33 in the event of a malfunction. Also, since the soot separator 32 and the relief valve 33 are arranged on the cylinder block 17, appropriate strength is ensured in the area where the soot separator 32 and the relief valve 33 are arranged.

[0038] Furthermore, in the return passage 31, the end opposite to the connection point to the supply passage 13 communicates with the oil reservoir 11 of the oil pan 5, and oil is discharged from the soot separator 32 through the return passage 31 to the oil pan 5. For this reason, the return passage 31 is not connected to the suction side (suction passage 12) of the pump 6. With this configuration, even if the soot separator 32 and the relief valve 33 are placed on the outer surface 21 of the cylinder block 17, the return passage 31 extending through the soot separator 32 and the relief valve 33 can be formed with a simple configuration.

[0039] Furthermore, in the embodiment, the return passage 31 branches off from the supply passage 13 upstream of the oil cooler 8. As a result, the inflow of oil cooled by the oil cooler 8 into the soot separation section 32 is appropriately suppressed. Consequently, relatively high-temperature oil is supplied to the soot separation section 32, and relatively low-viscosity oil is supplied to the soot separation section 32. Therefore, soot is further appropriately separated from the oil in the soot separation section 32, improving the soot collection efficiency.

[0040] Furthermore, in the example shown in Figure 2, the return passage 31 branches off from the supply passage 13 between the pump 6 and the oil filter 7. This configuration reduces the pressure at the discharge side (discharge port) of the pump 6 by at least an amount equivalent to the pressure loss in the oil filter 7, compared to a configuration where the return passage 31 branches off downstream of the oil filter 7. This further reduces the driving force of the pump 6.

[0041] Figure 4 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 2 according to a certain modification. In Figure 4, the walls separating the outside and inside of the internal combustion engine 2 in the oil pan 5, cylinder block 17, and cylinder head 18 are schematically shown. As shown in Figure 4, in this modification, the return passage 31 branches off from the supply passage 13 downstream of the oil filter 7. That is, the return passage 31 branches off from the supply passage 13 between the oil filter 7 and the oil cooler 8.

[0042] In the modified example shown in Figure 4, the oil system has the same configuration as the example in Figure 2, except that the branching position of the return channel 31 is different. Therefore, this modified example also produces the same functions and effects as the embodiments described above. In addition, in this modified example, since the return channel 31 branches off from the supply channel 13 downstream of the oil filter 7, the oil from which impurities have been removed by the oil filter 7 is supplied to the soot separation section 32. As a result, soot is further properly separated from the oil in the soot separation section 32, and the soot collection efficiency is improved.

[0043] Figure 5 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 2 according to a different modification from Figure 4. In Figure 5, the walls separating the outside and inside of the internal combustion engine 2 in the oil pan 5, cylinder block 17, and cylinder head 18 are schematically shown. As shown in Figure 5, in this modification, the internal combustion engine 2 is equipped with a removal device 40 that integrates an oil filter 7 and a soot separator 32. The removal device 40 is located on the outer surface 21 of the cylinder block 17. Therefore, in this modification as well, the oil filter 7, soot separator 32, and relief valve 33 are located on the outer surface of the cylinder block 17.

[0044] In the removal device 40, the part that functions as an oil filter 7 is separated from the part that functions as a soot separator 32. In the removal device 40, the supply channel 13 passes through the part that functions as an oil filter 7, and the return channel 31 passes through the part that functions as a soot separator 32. In the removal device 40, the part through which the supply channel 13 passes does not communicate with the part through which the return channel 31 passes. Due to this configuration, in the removal device 40, which integrates the oil filter 7 and the soot separator 32, the inflow of oil from the supply channel 13 to the return channel 31 and the inflow of oil from the return channel 31 to the supply channel 13 are suppressed.

[0045] In the modified example shown in Figure 5, the oil system has the same configuration as the example in Figure 2, except that the oil filter 7 and the soot separator 32 are integrated. Therefore, this modified example also provides the same functions and effects as the embodiments described above. Furthermore, in this modified example, since the oil filter 7 and the soot separator 32 are integrated, it becomes easier to mount the oil filter 7 and the soot separator 32 on the internal combustion engine 2. In addition, it becomes easier to replace the filter element 16 and the collecting material 36, improving the maintainability of the oil filter 7 and the soot separator 32.

[0046] Furthermore, in one modified configuration, similar to the configuration in Figure 4, the return passage 31 branches off from the supply passage 13 between the oil filter 7 and the oil cooler 8. And, similar to the configuration in Figure 5, the internal combustion engine 2 is equipped with a removal device 40 that integrates the oil filter 7 and the soot separation unit 32. This modified configuration also provides the same functions and effects as the embodiments described above.

[0047] Furthermore, in the above-described embodiment, the relief valve 33 is positioned between the branching point of the return passage 31 and the soot separation section 32, but this is not the only configuration. In one modified example, the relief valve 33 is positioned in the return passage 31 between the soot separation section 32 and the oil reservoir 11 of the oil pan 5. In this case, the soot separation section 32 is positioned between the branching point of the return passage 31 and the soot separation section 32. In this modified example as well, when the relief valve 33 positioned in the return passage 31 opens, the oil that has been diverted from the supply passage 13 to the return passage 31 flows through the soot separation section 32. Therefore, this modified example also produces the same functions and effects as the above-described embodiment.

[0048] Furthermore, the present invention is not limited to the embodiments described above, and can be modified in various ways during implementation without departing from its essence. The embodiments may also be combined as appropriate as possible, and the combined effects can be obtained in such cases. Moreover, the embodiments described above include inventions at various stages, and various inventions can be extracted by appropriate combinations of the multiple disclosed constituent elements. [Explanation of Symbols]

[0049] 1...Internal combustion engine system, 2...Internal combustion engine, 3...Controller, 5...Oil pan, 6...Pump, 7...Oil filter, 8...Oil cooler, 13...Supply passage (main supply passage), 17...Cylinder block, 21...Outer surface (outer wall surface), 22...Oil jet, 25...Piston, 27...Oil check valve, 31...Return passage, 32...Soot separation section, 33...Relief valve, 40...Removal equipment.

Claims

1. A pump that discharges oil, An oil filter for filtering the oil discharged from the pump, A supply channel extending from the pump through the oil filter, A return channel branching off from the aforementioned supply channel, The return channel includes a soot separation unit that collects soot contained in the oil, A relief valve is positioned in the return passage and, when opened, allows the oil diverted to the return passage to flow through the soot separation section. An internal combustion engine equipped with the following features.

2. An oil jet capable of discharging the oil supplied through the supply channel, A piston that is cooled by the oil discharged from the oil jet, Furthermore, it is equipped with, The operation of the relief valve is controlled in accordance with the supply state of the oil to the oil jet, thereby controlling the flow of the oil to the soot separation section through the return passage. An internal combustion engine according to claim 1.

3. The internal combustion engine according to claim 1, further comprising a cylinder block having an outer surface that forms part of the exterior, and the soot separation section and the relief valve being arranged on the outer surface.

4. The internal combustion engine according to claim 1, further comprising an oil pan through which the oil discharged by the pump is stored and through which the oil is discharged.

5. The supply channel further comprises an oil cooler, which is positioned downstream of the oil filter in the supply channel and cools the oil flowing through the supply channel. The return passage is located upstream of the oil cooler and branches off from the supply passage. An internal combustion engine according to claim 1.

6. An internal combustion engine according to any one of claims 1 to 5, A controller that controls the operation of the relief valve, An internal combustion engine system equipped with the following features.

7. The aforementioned internal combustion engine is An oil jet capable of discharging the oil supplied through the supply channel, A piston that is cooled by the oil discharged from the oil jet, Furthermore, The controller controls the supply of oil to the oil jet based on the temperature of the piston, and controls the operation of the relief valve in accordance with the oil supply state to the oil jet, thereby controlling the flow of oil to the soot separation section through the return passage. The internal combustion engine system according to claim 6.

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