JP6579160B2 - Oil circulation device for internal combustion engine - Google Patents

Description

  The present invention relates to an oil circulation device for an internal combustion engine.

  Oil is supplied to some components of the internal combustion engine (such as a crank journal) by an oil circulation device during operation of the internal combustion engine. The oil circulation device circulates oil between an oil pan that stores oil and an oil supplied portion to which the oil is supplied.

  In Patent Document 1, in order to reduce the mechanical resistance of the oil supplied part and improve the fuel efficiency of the internal combustion engine, the temperature of the oil supplied to the oil supplied part is raised using the heat of the exhaust gas. Is described. Specifically, during the warm-up operation of the internal combustion engine, the oil is heated by the high-temperature exhaust gas in the exhaust port by flowing a part of the oil through the oil passage near the exhaust port.

JP 2012-137016 A Japanese Patent Laid-Open No. 62-174517 Japanese Utility Model Publication No. 4-111505 JP-A-3-242418 JP 2010-024982 A

  However, in the oil circulation device described in Patent Document 1, during the warm-up operation of the internal combustion engine, the oil supplied to the oil passage in the vicinity of the exhaust port and each oil supplied portion without passing through the oil passage in the vicinity of the exhaust port Is returned to the same oil pan (inner oil pan). For this reason, since a small amount of heated oil and a large amount of unheated oil are mixed in the oil pan, the temperature of the entire oil cannot be increased effectively.

  On the other hand, the inventor of the present application pays attention to the relationship between the oil temperature and the mechanical resistance in each oil supplied part, and in order to improve the fuel consumption of the internal combustion engine, the oil supplied to all the oil supplied parts is not always hot. Found that there is no need to supply. Based on this fact, in the oil circulation device conceived by the inventor of the present application, a high-temperature side oil circulation path configured to supply oil heated by the heating unit to some of the oil-supplied units, and a heating A low-temperature side oil circulation path configured to supply oil not heated by the section to the remaining oil-supplied parts is provided separately. As a result, it is possible to quickly raise the temperature of the oil in the high-temperature side oil circulation path during the warm-up operation of the internal combustion engine, thereby improving the fuel efficiency of the internal combustion engine.

  However, when the internal combustion engine is stopped, the oil in the high temperature side oil circulation path is returned to the oil pan, and the air flowing in from the part opened to the atmosphere may stay in the heating part of the high temperature side oil circulation path. The air left in the heating unit prevents heat exchange between the surroundings of the heating unit and the oil flowing through the heating unit after the internal combustion engine is restarted. For this reason, when much air remains in a heating part, the temperature rise of the oil in a heating part is suppressed. The oil flowing through the heating unit also functions as a cooling medium that lowers the temperature around the heating unit. For this reason, if much air remains in the heating part, cooling of the surroundings of the heating part by oil is also suppressed.

  Accordingly, in view of the above problems, an object of the present invention is to provide an oil having a high temperature side oil circulation path configured to raise the temperature of the oil by the heating section and a low temperature side oil circulation path not provided with the heating section. In the circulation device, it is to promote the discharge of air in the heating part of the high-temperature side oil circulation path.

  The gist of the present disclosure is as follows.

  (1) A high temperature side oil pan for storing oil, a high temperature side oil pump for pumping oil from the high temperature side oil pan, and a heating unit for heating the oil supplied from the high temperature side oil pan by the high temperature side oil pump; The oil heated by the heating unit is supplied, and a high-temperature side oil supplied unit disposed at a position lower than the heating unit in the vertical direction is provided, the high-temperature side oil pan, the heating unit, and the A high temperature side oil circulation path for circulating oil between the high temperature side oil supplied part, a low temperature side oil pan for storing oil, a low temperature side oil pump for pumping oil from the low temperature side oil pan, and the low temperature side oil A low-temperature-side oil-supplied portion to which oil is supplied from the low-temperature-side oil pan by a pump, and the low-temperature-side oil pan and the low-temperature side An oil for an internal combustion engine, comprising: a low temperature side oil circulation path for circulating oil between the oil supply section and a ventilation path connected to the heating section and configured to exhaust air in the heating section Circulation device.

  (2) The oil circulation device for an internal combustion engine according to (1), wherein the air passage is connected to an uppermost part of the heating unit.

  (3) The oil circulation of the internal combustion engine according to (1) or (2), wherein the air passage is connected to the low-temperature side oil-supplied portion arranged at a position higher than the heating portion in the vertical direction. apparatus.

  (4) The oil circulation device for an internal combustion engine according to (1) or (2), wherein the air passage is connected to the high temperature side oil supplied portion.

  (5) The air passage is configured to return a part of the oil in the heating unit to the high temperature side oil pan, and the oil circulation device controls the on / off valve for opening and closing the air passage, and the on / off valve. The internal combustion engine oil circulation device according to (1) or (2), further including a valve control unit, wherein the valve control unit temporarily opens the on-off valve after the high temperature side oil pump is started.

  (6) The oil circulation device for an internal combustion engine according to (5), wherein the valve control unit opens the on-off valve until a reference time elapses after the high temperature side oil pump is started.

  (7) The air passage is configured to return a part of the oil in the heating unit to the high temperature oil pan, and the oil circulation device includes a first on-off valve that opens and closes the air passage, the heating unit, A second on-off valve that opens and closes the high-temperature side oil circulation path between the high-temperature side oil supplied portion, a valve control unit that controls the first on-off valve and the second on-off valve, and starting of the internal combustion engine A start timing control section for controlling the timing; and a pump control section for controlling the high temperature side oil pump. The pump control section starts the high temperature side oil pump when the start of the internal combustion engine is requested. The valve control unit opens the first on-off valve and closes the second on-off valve until a reference time elapses after the start of the internal combustion engine is requested, and the first on-off valve is operated during the operation of the internal combustion engine. Close the on-off valve and turn off the second on-off valve The internal combustion engine oil circulation device according to (1) or (2), wherein the start timing control unit starts the internal combustion engine after the reference time has elapsed since the start of the internal combustion engine was requested. .

  (8) A soak timer for detecting a stop time of the internal combustion engine is further provided, and the valve control unit relatively detects the stop time when the stop time of the internal combustion engine detected by the soak timer is relatively long. The oil circulation device for an internal combustion engine according to (6) or (7), wherein the reference time is lengthened as compared with a short case.

  (9) The oil circulation device for an internal combustion engine according to any one of (1) to (8), wherein the heating unit includes a heating oil passage formed around an exhaust port.

  (10) The oil circulation device for an internal combustion engine according to (9), wherein the heating oil passage has a protrusion that protrudes upward in the vertical direction, and the air passage is connected to a top of the protrusion.

  (11) The oil circulation device for an internal combustion engine according to any one of (1) to (10), wherein the high temperature side oil supplied portion includes a crank journal.

  According to the present invention, in an oil circulation device that includes a high-temperature side oil circulation path configured to raise the temperature of oil by a heating unit and a low-temperature side oil circulation path that is not provided with a heating unit, The exhaust of the air in the heating part of the path can be promoted.

FIG. 1 is a schematic side cross-sectional view of an internal combustion engine including an oil circulation device according to a first embodiment of the present invention. FIG. 2 is a diagram schematically showing the configuration of the oil circulation device for the internal combustion engine according to the first embodiment of the present invention. FIG. 3 is a diagram illustrating a specific example of the configuration of the oil circulation device. FIG. 4 is a plan sectional view of a cylinder head of the internal combustion engine. FIG. 5 is a cross-sectional view of the cylinder head taken along line VV in FIG. FIG. 6 is a cross-sectional view of the cylinder head taken along line VI-VI in FIG. FIG. 7 is a diagram schematically showing a configuration of an oil circulation device for an internal combustion engine according to the second embodiment of the present invention. FIG. 8 is a diagram schematically showing the configuration of an oil circulation device for an internal combustion engine according to the third embodiment of the present invention. FIG. 9 is a flowchart showing a control routine of the air discharge process in the third embodiment of the present invention. FIG. 10 is a diagram schematically showing a configuration of an oil circulation device for an internal combustion engine according to the fourth embodiment of the present invention. FIG. 11 is a flowchart showing a control routine of air discharge processing in the fourth embodiment of the present invention. FIG. 12 is a diagram schematically showing the configuration of an oil circulation device for an internal combustion engine according to the fifth embodiment of the present invention. FIG. 13 is a flowchart showing a control routine of air discharge processing in the fifth embodiment of the present invention. FIG. 14 is a map showing the relationship between the stop time of the internal combustion engine and the reference time.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same reference numerals are assigned to similar components.

<First embodiment>
First, a first embodiment of the present invention will be described with reference to FIGS.

<Configuration of internal combustion engine>
FIG. 1 is a schematic side sectional view of an internal combustion engine 100 including an oil circulation device according to a first embodiment of the present invention. As shown in FIG. 1, the internal combustion engine 100 includes a crankcase 2, a cylinder block 3, a cylinder head 4, a piston 5, and a combustion chamber 6. The cylinder block 3 is disposed on the crankcase 2. The cylinder head 4 is disposed on the cylinder block 3. The piston 5 reciprocates up and down in a cylinder formed in the cylinder block 3. The combustion chamber 6 is defined by the cylinder head 4, the cylinder and the piston 5.

  The cylinder head 4 is provided with an ignition plug 7 that is disposed at the center of the top surface of the combustion chamber 6 and ignites the air-fuel mixture in the combustion chamber 6, and a fuel injection valve 8 that injects fuel into the combustion chamber 6. .

  The cylinder head 4 is provided with an intake port 10 through which intake gas flows, and an intake valve 11 that opens and closes the intake port 10. The upper end portion of the intake valve 11 is disposed so as to be in contact with one end portion of the intake rocker arm 12. The intake rocker arm 12 is disposed such that the other end thereof is in contact with the intake lash adjuster 13 and the center thereof is in contact with the intake cam 14. The intake lash adjuster 13 urges the intake rocker arm 12 so that the valve clearance of the intake valve 11 becomes zero.

  The intake cam 14 is fixed to the intake camshaft 15 and rotates with the rotation of the intake camshaft 15. The intake camshaft 15 is supported by a bearing (not shown) formed on the cylinder head 4 and rotates within the bearing. In the present embodiment, the bearing that supports the intake camshaft is a sliding bearing, and the intake cam journal provided on the intake camshaft 15 rotates within this bearing.

  When the intake camshaft 15 rotates, the intake cam 14 rotates accordingly, and the intake rocker arm 12 is pushed by the intake cam 14. When the intake rocker arm 12 is pushed by the intake cam 14 in this manner, the intake rocker arm 12 swings downward with the end portion in contact with the intake lash adjuster 13 as a fulcrum. As a result, the intake valve 11 is opened.

  In the present embodiment, an intake variable valve timing mechanism (VVT mechanism) is provided at the end of the intake camshaft 15. This VVT mechanism changes the valve timing of the intake valve 11 by changing the relative angle between the intake cam pulley driven by the timing belt and the intake camshaft by hydraulic pressure. The VVT mechanism is connected to an oil control valve (OCV), and the valve timing of the intake valve 11 is controlled by controlling the hydraulic pressure supplied to the VVT mechanism by this OCV.

  In addition, the cylinder head 4 is provided with an exhaust port 20 through which exhaust gas flows, and an exhaust valve 21 that opens and closes the exhaust port 20. The upper end portion of the exhaust valve 21 is disposed so as to contact one end portion of the exhaust rocker arm 22. The exhaust rocker arm 22 is disposed so that the other end thereof is in contact with the exhaust lash adjuster 23 and the center thereof is in contact with the exhaust cam 24. The exhaust lash adjuster 23 urges the exhaust rocker arm 22 so that the valve clearance of the exhaust valve 21 becomes zero.

  The exhaust cam 24 is fixed to the exhaust camshaft 25 and rotates as the exhaust camshaft 25 rotates. The exhaust camshaft 25 is supported by a bearing (not shown) formed on the cylinder head 4 and rotates within the bearing. In the present embodiment, the bearing that supports the exhaust camshaft 25 is a sliding bearing, and the exhaust cam journal provided on the exhaust camshaft 25 rotates within this bearing. An exhaust variable valve timing mechanism may also be provided at the end of the exhaust camshaft.

  The piston 5 is connected to the crankshaft 26 via a connecting rod 28. The connecting rod 28 is connected to the piston pin 29 at one end and is connected to the crank pin 27 of the crankshaft 26 at the other end. The connecting rod 28 is connected to the piston pin 29 and the crankpin 27 so as to convert the reciprocating motion of the piston 5 into the rotational motion of the crankshaft 26.

  The crankshaft 26 is supported by a bearing (not shown) formed in the cylinder block 3 and rotates in this bearing. In the present embodiment, the bearing that supports the crankshaft 26 is a sliding bearing, and a crank journal provided on the crankshaft 26 rotates within this bearing. In the present embodiment, the bearing for the crankshaft 26 is formed in the cylinder block 3, but it may be formed so that a half body is provided in both the cylinder block 3 and the crankcase 2.

<Configuration of oil circulation device>
FIG. 2 is a diagram schematically showing the configuration of the oil circulation device 1 of the internal combustion engine 100 according to the first embodiment of the present invention. The oil circulation device 1 supplies oil to a target component in order to lubricate, cool, or operate some components provided in the internal combustion engine 100. The oil circulation device 1 is configured so that the temperature of the oil is rapidly raised during the warming-up operation of the internal combustion engine 100, and the oil is slowly raised in temperature with the warming up of the internal combustion engine. The low temperature side oil circulation path 30 comprised is provided. The high temperature side oil circulation path 40 and the low temperature side oil circulation path 30 circulate oil independently of each other.

  In the low temperature side oil circulation path 30, oil is stored from the low temperature side oil pan 31 by the low temperature side oil pan 31 that stores oil, the low temperature side oil pump 32 that pumps oil from the low temperature side oil pan 31, and the low temperature side oil pump 32. A low temperature side oil supplied part 33 to be supplied is provided. The low temperature side oil circulation path 30 circulates oil between the low temperature side oil pan 31 and the low temperature side oil supplied portion 33.

  As shown in FIG. 1, the low temperature side oil pan 31 is directly attached to the crankcase 2 so as to cover the entire opening below the crankcase 2. The low temperature side oil pump 32 pumps the oil in the low temperature side oil pan 31 through a low temperature side oil strainer (not shown) that removes foreign matters in the oil. The low temperature side oil pump 32 supplies the oil in the low temperature side oil pan 31 to the low temperature side oil supplied portion 33. The low temperature side oil pump 32 is a mechanical oil pump or an electric oil pump. The mechanical oil pump is driven by rotation of the crankshaft 26, and the electric oil pump is driven by electric power supplied from a battery.

  High pressure oil pressurized by the low temperature side oil pump 32 flows through the low temperature side high pressure oil passage 35 between the low temperature side oil pump 32 and the low temperature side oil supplied portion 33. The oil supplied to the low temperature side oil supplied part 33 is released to the atmosphere and falls to the low temperature side oil pan 31 by gravity. Accordingly, the oil supplied from the low temperature side oil pan 31 to the low temperature side oil supplied portion 33 is returned to the low temperature side oil pan 31 again. The low temperature side high pressure oil passage 35 may be provided with a low temperature side oil filter for removing minute foreign matters in the oil.

  The high temperature side oil circulation path 40 is supplied from the high temperature side oil pan 41 by the high temperature side oil pan 41 that stores oil, the high temperature side oil pump 42 that pumps oil from the high temperature side oil pan 41, and the high temperature side oil pump 42. A heating unit 44 that heats the oil and a high-temperature side oil supplied unit 43 that is supplied with the oil heated by the heating unit 44 are provided. The high temperature side oil pump 42 and the high temperature side oil supplied part 43 are arranged at a position lower than the heating part 44 in the vertical direction. The high temperature side oil circulation path 40 circulates oil among the high temperature side oil pan 41, the heating unit 44, and the high temperature side oil supplied unit 43.

  The high temperature side oil pan 41 is disposed inside the low temperature side oil pan 31. In other words, the low temperature side oil pan 31 is disposed so as to surround the high temperature side oil pan 41. The volume of the high temperature side oil pan 41 is smaller than the capacity of the low temperature side oil pan 31, and the amount of oil stored in the high temperature side oil pan 41 is smaller than the amount of oil stored in the low temperature side oil pan 31. As a result, the temperature rise of the oil in the high temperature side oil circulation path 40 can be promoted.

  In addition, the structure of the high temperature side oil pan 41 and the low temperature side oil pan 31 is not limited to the above. For example, the high temperature side oil pan 41 may be disposed adjacent to the low temperature side oil pan 31. In this case, the high temperature side oil pan 41 is disposed outside the low temperature side oil pan 31. Further, the volume of the high temperature side oil pan 41 is larger than the capacity of the low temperature side oil pan 31, and the amount of oil stored in the high temperature side oil pan 41 is larger than the amount of oil stored in the low temperature side oil pan 31. May be.

  The high temperature side oil pump 42 is a mechanical oil pump or an electric oil pump like the low temperature side oil pump 32. In the present embodiment, the high temperature side oil pump 42 and the low temperature side oil pump 32 are separate pumps, but may be an integral oil pump. In this case, for example, two pump mechanisms having independent oil passages are provided in one oil pump, and these two pump mechanisms are driven by one drive shaft.

  The heating unit 44 is an oil passage formed around the exhaust passage of the internal combustion engine 100, for example. In this case, the oil flowing through the heating unit 44 is heated by heat exchange with the high-temperature exhaust gas flowing through the exhaust passage. Further, since the exhaust gas immediately after being discharged from the combustion chamber 6 flows through the exhaust port 20, generally the temperature in the exhaust port 20 is an exhaust passage (exhaust manifold, exhaust pipe, etc.) downstream of the exhaust port 20. ). For this reason, by using the first heating oil passage 51 formed around the exhaust port 20 as a heating unit, it is possible to further increase the temperature of the oil. For example, as shown in FIG. 1, the first heating oil passage 51 is formed in the cylinder head 4 so as to extend in the horizontal direction in the vicinity of the exhaust port 20 connected to each cylinder.

  The heating unit 44 may be a second heating oil passage 52 formed around each cylinder. In this case, the oil flowing through the second heating oil passage 52 is heated by the heat generated in the combustion chamber 6 by the combustion of the air-fuel mixture. For example, the second heating oil passage 52 is formed in the cylinder block 3 so as to partially extend in the circumferential direction of each cylinder and also extend in the axial direction of each cylinder as shown in FIG. The first heating oil passage 51 and the second heating oil passage 52 may be used in combination as the heating unit 44.

  The oil heated by the heating unit 44 is supplied to the high temperature side oil supplied unit 43. High pressure oil pressurized by the high temperature side oil pump 42 flows through the high temperature side high pressure oil passage 45 between the high temperature side oil pump 42 and the high temperature side oil supplied portion 43. Moreover, it is preferable that the high temperature side high pressure oil path 45 other than the heating part 44 is thermally insulated from the periphery by heat insulation materials, such as resin, in order to suppress that the temperature of oil falls.

  The oil supplied to the high temperature side oil supplied portion 43 is released to the atmosphere and falls to the high temperature side oil pan 41 by gravity. Therefore, the oil supplied from the high temperature side oil pan 41 to the high temperature side oil supplied portion 43 is returned to the high temperature side oil pan 41 again. The high temperature side high pressure oil passage 45 may be provided with a high temperature side oil filter for removing minute foreign matters in the oil.

  In the present embodiment, the high temperature side oil circulation path 40 is provided separately from the low temperature side oil circulation path 30 in the internal combustion engine 100. For this reason, since the amount of oil smaller than the total amount of oil is held in the high temperature side oil circulation path 40, the oil in the high temperature side oil circulation path 40 is quickly heated by the oil heated in the heating unit 44. Can be made. Further, since the oil supplied to the low temperature side oil supplied portion 33 is not returned to the high temperature side oil pan 41, the temperature of the oil in the high temperature side oil circulation path 40 is prevented from being lowered by the oil that does not pass through the heating portion 44. can do. As a result, the temperature rise of the oil in the high temperature side oil circulation path 40 is promoted.

  In the present embodiment, the high temperature side oil circulation path 40 is configured so that oil circulates in the order of the high temperature side oil pan 41, the heating unit 44, and the high temperature side oil supplied unit 43. That is, in the high temperature side oil circulation path 40, the oil is directly supplied from the heating unit 44 to the high temperature side oil supplied unit 43. As a result, since the oil having the highest temperature in the high temperature side oil circulation path 40 is supplied to the high temperature side oil supplied portion 43, the temperature of the oil supplied to the high temperature side oil supplied portion 43 can be quickly raised. it can.

  As described above, each oil circulation path is provided with an oil-supplied portion that is an oil supply target. The oil-supplied portion is a component that is lubricated by oil, a component that is cooled by oil, a component that is actuated by oil, or the like. The high temperature side oil supplied part 43 and the low temperature side oil supplied part 33 are selected from the oil supplied parts as follows, for example.

  In the oil circulation device 1 provided in the internal combustion engine 100 shown in FIG. 1, the oil supplied portion includes a crank journal 61, a crankpin 27, a VVT mechanism 81, a cam journal 83, lash adjusters 13 and 23, and a piston 5. FIG. 3 is a diagram illustrating a specific example of the configuration of the oil circulation device 1. In the example of FIG. 3, the heating unit 44 is a first heating oil passage 51 formed around the exhaust port 20.

  As described above, the crank journal 61 is supported in the bearing formed in the cylinder block 3 and rotates in this bearing. In the crank journal 61 which is an oil supply part, oil is supplied between the crank journal 61 and the bearing formed in the cylinder block 3. Since this bearing is a sliding bearing, fluid lubrication is performed between the crank journal 61 and the bearing by the supplied oil, thereby reducing the frictional resistance.

  The crank pin 27 is supported in a bearing formed at the lower end portion of the connecting rod 28 and is rotated in the bearing. In the crankpin 27 which is an oil supply portion, oil is supplied between the crankpin 27 and a bearing formed on the connecting rod 28. Since this bearing is also a sliding bearing, fluid lubrication is performed between the crankpin 27 and the bearing by the supplied oil, thereby reducing the frictional resistance.

  In the VVT mechanism 81, oil is used as hydraulic oil. When oil is supplied to one hydraulic chamber of the VVT mechanism 81, the intake camshaft 15 rotates to the advance side with respect to the intake cam pulley, so that the valve timing of the intake valve 11 is advanced. On the other hand, when oil is supplied to the other hydraulic chamber of the VVT mechanism 81, the intake camshaft 15 rotates to the retard side with respect to the intake cam pulley, and thus the valve timing of the intake valve 11 is retarded. The supply of oil to each hydraulic chamber of the VVT mechanism 81 is controlled by the OCV 82. Therefore, the oil supplied to the OCV 82 is used to drive the VVT mechanism 81 that is an oil supplied part.

  The cam journal 83 includes an intake cam journal formed on the intake camshaft 15 and an exhaust cam journal formed on the exhaust camshaft 25. As described above, the cam journal 83 is supported by the bearing formed on the cylinder head 4 and rotates within the bearing. In the cam journal 83 which is an oil supply part, oil is supplied between the cam journal 83 and a bearing formed on the cylinder head 4. Since this bearing is also a sliding bearing, fluid lubrication is performed between the cam journal 83 and the bearing by the supplied oil, thereby reducing the frictional resistance.

  In the intake lash adjuster 13, oil is used as the working oil. When a valve clearance is generated between the intake rocker arm 12 and the intake cam 14, the intake lash adjuster 13 is pushed out by the supplied oil. Similarly, in the exhaust lash adjuster 23, oil is used as the working oil, and when the valve clearance is generated between the exhaust rocker arm 22 and the exhaust cam 24, the exhaust lash adjuster 23 is extended by the supplied oil.

  As shown in FIG. 1, the oil jet 84 is attached to the cylinder block 3 below each cylinder and injects oil toward the inside of the piston 5. Oil injected from the oil jet 84 cools the piston 5 and is supplied between the piston pin 29 and a bearing formed at the upper end of the connecting rod 28. Since this bearing is also a sliding bearing, fluid lubrication is performed between the piston pin 29 and the bearing by the supplied oil, thereby reducing the frictional resistance.

  Further, during the reciprocating motion of the piston 5, the piston 5 swings in the cylinder around the piston pin 29. As a result, during the reciprocating motion of the piston 5, the piston skirt 5a of the piston 5 and the cylinder wall surface slide in contact with each other. Since the oil jetted from the oil jet 84 also adheres to the cylinder wall surface, the oil is supplied between the cylinder wall surface and the piston skirt 5a. Therefore, fluid lubrication is performed between the piston skirt 5a of the piston 5 and the wall surface of the cylinder by the supplied oil, thereby reducing the frictional resistance.

  In a structural member in which fluid lubrication is performed, such as a structural member having a slide bearing, when the temperature of supplied oil is low and the viscosity of the oil is high, the mechanical resistance increases and the fuel consumption of the internal combustion engine 100 deteriorates. For this reason, in order to improve the fuel efficiency of the internal combustion engine 100, it is necessary to quickly raise the temperature of the oil supplied to the structural member where fluid lubrication is performed, for example, when the internal combustion engine 100 is cold started.

  For this reason, the high temperature side oil supplied part 43 includes at least a part of a structural member in which fluid lubrication is performed, for example, at least a part of a structural member having a sliding bearing. The components for which fluid lubrication is performed are the crank journal 61, the crank pin 27, the cam journal 83, the piston skirt 5a (piston 5), and the like. Moreover, in this embodiment, the structural member arrange | positioned in the position lower than the heating part 44 in the vertical direction is selected as the high temperature side oil supply part 43.

  In the example shown in FIG. 3, the high temperature side oil supplied portion 43 includes a crank journal 61 and a crank pin 27. The crank journal 61 receives a particularly large load among the components that are subjected to fluid lubrication. For this reason, the remarkable fuel-consumption improvement effect can be acquired by heating up the oil supplied to the crank journal 61 rapidly, and reducing mechanical resistance. In addition, since only a part of the components that are subjected to fluid lubrication is used as the high temperature side oil supplied portion 43, the amount of oil in the high temperature side oil circulation path 40 can be further reduced, and the high temperature side oil circulation path can be reduced. The temperature increase of the oil in 40 can be promoted.

  The low temperature side oil supplied part 33 includes an oil supplied part that is not included in the high temperature side oil supplied part 43. In the example shown in FIG. 3, the low temperature side oil supplied portion 33 includes a VVT mechanism 81, a cam journal 83, lash adjusters 13 and 23, and a piston 5. Moreover, the low temperature side oil supply part 33 may include a fuel pump or a vacuum pump.

  The high temperature side oil supplied part 43 may include a piston skirt 5a (piston 5) in which fluid lubrication is performed. Further, the balance shaft and the turbocharger are also oil-supplied portions that have sliding bearings and are subjected to fluid lubrication. For this reason, when the internal combustion engine 100 is provided with a balance shaft, the high temperature side oil supplied portion 43 may include a balance shaft. Similarly, when the internal combustion engine 100 is provided with a turbocharger, the high temperature side oil supplied portion 43 may include a turbocharger.

  When the internal combustion engine 100 stops, the operations of the high temperature side oil pump 42 and the low temperature side oil pump 32 are also stopped. As a result, the oil in the high temperature side oil circulation path 40 is returned to the high temperature side oil pan 41, and the oil in the low temperature side oil circulation path 30 is returned to the low temperature side oil pan 31.

  In the present embodiment, the high temperature side oil pan 41 and the low temperature side oil pan 31 are configured so that the oil in the high temperature side oil pan 41 and the oil in the low temperature side oil pan 31 are mixed when the internal combustion engine 100 stops. The As a result, only specific oil can be prevented from receiving a heat load in the high temperature side oil circulation path 40, and the heat load can be dispersed throughout the oil. As a result, oil deterioration can be suppressed. For example, the high temperature side oil pan 41 and the low temperature side oil pan 31 are the low temperature side oil pan 31 and the high temperature side oil pan 41 when the internal combustion engine 100 is stopped and the oil is returned to the low temperature side oil pan 31 and the high temperature side oil pan 41. It is configured so that the inside oil can get over the peripheral wall of the high temperature side oil pan 41.

  Further, when the internal combustion engine 100 is stopped and oil is discharged from the high temperature side high pressure oil passage 45 of the high temperature side oil circulation passage 40, the high temperature side high pressure oil passage 45 passes through the gap between the high temperature side oil pump 42 and the high temperature side oil supplied portion 43. Air flows into the. The air that has flowed into the high temperature side high pressure oil passage 45 proceeds toward the heating unit 44 and then stays in the heating unit 44. When the internal combustion engine 100 is restarted and oil is supplied to the heating unit 44, the air in the heating unit 44 is pushed out by the oil in the oil traveling direction. However, there is a space in the heating unit 44 where oil does not spread. Since air rises due to buoyancy, air tends to remain particularly at the top of the heating unit 44.

  The air left in the heating unit 44 prevents heat exchange between the surroundings of the heating unit 44 and the oil flowing through the heating unit 44. For this reason, when much air remains in the heating part 44, the temperature rise of the oil in the heating part 44 is suppressed. Further, the oil flowing through the heating unit 44 also functions as a cooling medium that lowers the temperature around the heating unit 44. For this reason, if much air remains in the heating part 44, cooling of the surroundings of the heating part 44 by oil will also be suppressed.

  On the other hand, in the present embodiment, the oil circulation device 1 includes an air passage 46 that is connected to the heating unit 44 and configured to discharge air in the heating unit 44. As a result, the air staying in the heating unit 44 is also discharged from the air passage 46, so that the discharge of air in the heating unit 44 can be promoted. Preferably, the air passage 46 is connected to the uppermost part of the heating unit 44. Thus, the air left on the upper portion of the heating unit 44 without being discharged by the oil can be effectively discharged.

  Hereinafter, an example of the configuration of the heating unit 44 and the air passage 46 when the first heating oil passage 51 is used as the heating unit 44 will be described. FIG. 4 is a plan sectional view of the cylinder head 4 of the internal combustion engine 100. In the example illustrated in FIG. 4, the internal combustion engine 100 includes four cylinders # 1 to # 4 arranged in series. That is, the internal combustion engine 100 is an in-line four-cylinder internal combustion engine.

  Each of the cylinders # 1 to # 4 is provided with a pair of intake valves 11 and a pair of exhaust valves 21. Each intake port 10 opens to the side of the cylinder head 4 on the intake valve 11 side. On the other hand, the respective exhaust ports 20 are integrated in a common exhaust collecting portion 62, and the exhaust collecting portion 62 opens at a side portion of the cylinder head 4 on the exhaust valve 21 side. That is, the cylinder head 4 is an exhaust manifold integrated cylinder head.

  A flange 64 of an exhaust pipe 63 is bolted to the cylinder head 4 around the opening of the exhaust collection part 62, and the exhaust collection part 62 is connected to the exhaust pipe 63. FIG. 1 is a cross-sectional view of the internal combustion engine 100 taken along the line II in FIG.

  FIG. 5 is a cross-sectional view of the cylinder head 4 taken along line VV in FIG. The first heating oil passage 51 used as the heating part 44 is formed around the exhaust port 20 and the exhaust collecting part 62 and extends in the arrangement direction of the cylinders # 1 to # 4. The oil pumped up from the high temperature side oil pan 41 by the high temperature side oil pump 42 flows into the first heating oil passage 51 from the inlet 51 a of the first heating oil passage 51 through the high temperature side high pressure oil passage 45. Further, the oil that has flowed into the first heating oil passage 51 flows out from the outlet 51 b of the first heating oil passage 51 through the first heating oil passage 51. The opening area of the inlet 51a and the opening area of the outlet 51b are substantially equal.

  The first heating oil passage 51 includes an upper oil passage 51 c formed around the upper portions of the exhaust port 20 and the exhaust collecting portion 62, and a lower oil passage formed around the lower portions of the exhaust port 20 and the exhaust collecting portion 62. 51d. The upper oil passage 51c and the lower oil passage 51d extend in the arrangement direction of the cylinders # 1 to # 4.

  The first heating oil passage 51 includes a first connection oil passage 51e that supplies oil from the inlet 51a to the upper oil passage 51c and the lower oil passage 51d, and an outlet 51b from the upper oil passage 51c and the lower oil passage 51d. A second connecting oil passage 51f for supplying oil. The first connection oil passage 51e and the second connection oil passage 51f extend in the vertical direction and connect the upper oil passage 51c and the lower oil passage 51d.

  FIG. 6 is a cross-sectional view of the cylinder head 4 taken along line VI-VI in FIG. As can be seen from FIGS. 1 and 6, the upper oil passage 51c and the lower oil passage 51d in a cross section perpendicular to the extending direction of the upper oil passage 51c and the lower oil passage 51d, that is, the arrangement direction of the cylinders # 1 to # 4. This shape changes along the arrangement direction of the cylinders # 1 to # 4 so that the upper oil passage 51c and the lower oil passage 51d do not contact the exhaust port 20 and the exhaust collecting portion 62.

  The sum of the cross-sectional areas of the upper oil passage 51c and the lower oil passage 51d in the cross section perpendicular to the extending direction of the upper oil passage 51c and the lower oil passage 51d is larger than the opening area of the inlet 51a and the opening area of the outlet 51b. large. By increasing the cross-sectional area of the upper oil passage 51c and the lower oil passage 51d, heat exchange between the oil flowing through the first heating oil passage 51 and the exhaust gas flowing through the exhaust port 20 and the exhaust collecting portion 62 can be promoted. it can. As a result, the temperature rise of the oil in the heating unit 44 (first heating oil passage 51) is promoted.

  The first heating oil passage 51 has a protruding portion 51g that protrudes upward in the vertical direction. The protruding portion 51g has a convex shape upward, and is connected to the upper oil passage 51c. The top of the protrusion 51 g is located at the top of the first heating oil passage 51. An air passage 46 is connected to the top of the protruding portion 51g. The air passage 46 is open to the atmosphere. The air that has not been discharged by the oil tends to collect in the protrusion 51g due to buoyancy. For this reason, the protrusion 51g which collects air is provided, and the air in the 1st heating oil path 51 can be discharged | emitted effectively by connecting the ventilation path 46 to the protrusion 51g.

  An exhaust manifold may be provided outside the cylinder head 4, and each exhaust port 20 may be integrated outside the cylinder head 4. In this case, the first heating oil passage 51 is formed around the exhaust port 20 and extends in the arrangement direction of the cylinders # 1 to # 4. Moreover, the 1st heating oil path 51 does not need to have the protrusion part 51g. In this case, the air passage 46 is connected to, for example, the upper oil passage 51c. Further, the air passage 46 may be connected to a portion other than the uppermost portion of the first heating oil passage 51. Also in this case, since at least a part of the air in the first heating oil passage 51 is discharged from the ventilation passage 46, the discharge of the air in the first heating oil passage 51 is promoted. Further, when the second heating oil passage 52 is used as the heating unit 44, the ventilation passage 46 is connected to the second heating oil passage 52.

<Second embodiment>
The oil circulation device of the internal combustion engine according to the second embodiment is basically the same as the configuration and control of the oil circulation device of the internal combustion engine according to the first embodiment, except for the points described below. For this reason, the second embodiment of the present invention will be described below with a focus on differences from the first embodiment.

  When the air passage 46 is provided as in the first embodiment, a part of the oil in the heating portion 44 flows out of the air passage 46 after the air in the heating portion 44 is exhausted. The oil that flows out from the air passage 46 is released to the atmosphere and falls to the high temperature side oil pan 41. Therefore, a part of the oil is returned to the high temperature side oil pan 41 without being supplied to the oil supplied portion, so that a part of the work amount of the high temperature side oil pump 42 is wasted and the fuel consumption of the internal combustion engine 100 is deteriorated. .

  Therefore, the oil circulation device according to the second embodiment is configured as follows. FIG. 7 is a diagram schematically showing the configuration of an oil circulation device 1a for an internal combustion engine according to the second embodiment of the present invention. In the second embodiment, the air passage 46 is connected to the low temperature side oil supplied part 33. That is, the air passage 46 connects the heating unit 44 and the low temperature side oil supplied unit 33. For this reason, the oil discharged from the heating part 44 to the ventilation path 46 is supplied to the low temperature side oil supplied part 33. The low temperature side oil supplied part 33 connected to the ventilation path 46 is a component arranged at a position higher than the heating part 44 in the vertical direction, for example, the VVT mechanism 81, the cam journal 83, the lash adjusters 13, 13, fuel. Pumps, vacuum pumps, etc.

  According to the above-described configuration, since oil is supplied from the heating unit 44 to a part of the low temperature side oil supplied portion 33, the number of oil supplied portions to which oil is supplied by the low temperature side oil pump 32 can be reduced. it can. For this reason, the work amount of the low temperature side oil pump 32 can be reduced, and as a result, deterioration of the fuel consumption of the internal combustion engine 100 when the air passage 46 is provided can be suppressed.

  The air passage 46 is configured such that the amount of oil discharged from the heating unit 44 to the air passage 46 is smaller than the amount of oil supplied from the heating unit 44 to the high temperature side oil supplied portion 43. . As a result, it is possible to suppress a decrease in the temperature rise effect of the oil in the high temperature side oil circulation path 40 and to suppress a shortage of oil in the high temperature side oil circulation path 40 during operation of the internal combustion engine 100. can do. For example, the amount of oil discharged from the heating unit 44 to the ventilation path 46 is about 2 to 5% of the total amount of oil flowing into the heating unit 44.

  The air passage 46 may be connected to the high temperature side oil supplied portion 43 instead of the low temperature side oil supplied portion 33. In this case, the oil discharged from the heating unit 44 to the ventilation path 46 is supplied to the high temperature side oil supplied unit 43. By this, it can suppress more that the temperature rise effect of the oil in the high temperature side oil circulation path 40 falls.

<Third embodiment>
The oil circulation device for an internal combustion engine according to the third embodiment is basically the same as the configuration and control of the oil circulation device for the internal combustion engine according to the first embodiment, except for the points described below. For this reason, the third embodiment of the present invention will be described below with a focus on differences from the first embodiment.

  When the air passage 46 is provided as in the first embodiment, a part of the oil in the heating portion 44 flows out of the air passage 46 after the air in the heating portion 44 is exhausted. The oil that flows out from the air passage 46 is released to the atmosphere and falls to the high temperature side oil pan 41. For this reason, since the oil that has not been sufficiently heated in the heating unit 44 is returned to the high temperature side oil pump 42, the oil temperature rise effect in the high temperature side oil circulation path 40 is reduced.

  Therefore, the oil circulation device according to the third embodiment is configured as follows. FIG. 8 is a diagram schematically showing the configuration of an oil circulation device 1b for an internal combustion engine according to the third embodiment of the present invention. In the third embodiment, the air passage 46 is configured to return part of the oil in the heating unit 44 to the high temperature side oil pan 41. The oil that has passed through the air passage 46 is released to the atmosphere and falls to the high temperature side oil pan 41 by gravity.

  The oil circulation device 1 b includes an on-off valve 70 that opens and closes the air passage 46 and a valve control unit 91 that controls the on-off valve 70. The on-off valve 70 is provided in the ventilation path 46. The oil and air in the heating unit 44 can pass through the on-off valve 70 when the on-off valve 70 is opened by the valve control unit 91, and the on-off valve 70 can be opened when the on-off valve 70 is closed by the valve control unit 91. Can't pass.

  In the present embodiment, an electronic control unit (ECU) 90 functions as the valve control unit 91. The ECU 90 is a microcomputer including a central processing unit (CPU), a memory such as a read only memory (ROM) and a random access memory (RAM), an input port, an output port, and the like. The ECU 90 controls various actuators of the internal combustion engine 100 based on outputs from various sensors. In the present embodiment, one ECU 90 is provided, but a plurality of ECUs may be provided for each function.

  The valve control unit 91 temporarily opens the on-off valve 70 after the high temperature side oil pump 42 is started. When the high temperature side oil pump 42 is a mechanical variable displacement oil pump, the high temperature side oil pump 42 is started at the start of cranking. When the high temperature side oil pump 42 is an electric variable displacement oil pump, the ECU 90 starts the high temperature side oil pump 42 at a predetermined timing. For example, when the start of the internal combustion engine 100 is requested, the ECU 90 starts the high temperature side oil pump 42 before the start of cranking. Further, the ECU 90 may start the high temperature side oil pump 42 at the start of cranking.

  By opening the on-off valve 70 temporarily, air that has flowed into the heating unit 44 while the internal combustion engine 100 is stopped can be discharged from the air passage 46. Moreover, since the on-off valve 70 is temporarily opened, the amount of oil returned from the heating unit 44 to the high temperature side oil pan 41 can be reduced, and the oil temperature rising effect in the high temperature side oil circulation path 40 is reduced. This can be suppressed.

  For example, the valve control unit 91 opens the on-off valve 70 until the reference time elapses after the high temperature side oil pump 42 is started. The reference time is determined in advance, and is set to, for example, a time required to discharge the air in the heating unit 44 from the air passage 46 when the most air stays in the heating unit 44. With this control, the air that has flowed into the heating unit 44 while the internal combustion engine 100 is stopped can be quickly discharged immediately after the high temperature side oil pump 42 is started.

<Air discharge treatment>
Hereinafter, with reference to the flowchart of FIG. 9, the control for discharging the air in the heating unit 44 in the third embodiment will be described. FIG. 9 is a flowchart showing a control routine of the air discharge process in the third embodiment of the present invention. This control routine is repeatedly executed at predetermined time intervals by the ECU 90 after the high temperature side oil pump 42 is started.

  First, in step S101, the valve control unit 91 determines whether or not the elapsed time ET from the start of the high temperature side oil pump 42 is equal to or longer than the reference time Tref. When it is determined that the elapsed time ET is less than the reference time Tref, the present control routine proceeds to step S102. In step S102, the valve control unit 91 opens the on-off valve 70. After step S102, this control routine ends.

  On the other hand, if it is determined in step S101 that the elapsed time ET is greater than or equal to the reference time Tref, the present control routine proceeds to step S103. In step S <b> 103, the valve control unit 91 closes the on-off valve 70. After step S103, this control routine ends.

  This control routine may be executed after a predetermined time has elapsed since the high temperature side oil pump 42 was started. That is, the valve control unit 91 may open the on-off valve 70 for a reference time after a predetermined time has elapsed since the high temperature side oil pump 42 was started.

<Fourth embodiment>
The oil circulation device for an internal combustion engine according to the third embodiment is basically the same as the configuration and control of the oil circulation device for the internal combustion engine according to the first embodiment, except for the points described below. For this reason, the fourth embodiment of the present invention will be described below with a focus on differences from the first embodiment.

  When the internal combustion engine 100 is restarted and oil is supplied to the heating unit 44, the air in the heating unit 44 is pushed out by the oil in the oil traveling direction. On the other hand, the air in the heating unit 44 tends to rise due to buoyancy. As a result, the pressing force by the oil and the buoyancy of the air are balanced, and air may not be discharged from the heating unit 44.

  Therefore, the oil circulation device according to the fourth embodiment is configured as follows. FIG. 10 is a diagram schematically showing the configuration of an oil circulation device 1c for an internal combustion engine according to the fourth embodiment of the present invention. In the third embodiment, the air passage 46 is configured to return part of the oil in the heating unit 44 to the high temperature side oil pan 41. The oil that has passed through the air passage 46 is released to the atmosphere and falls to the high temperature side oil pan 41 by gravity.

  The oil circulation device 1 c includes a first on-off valve 71, a second on-off valve 72, and a valve control unit 91 that controls the first on-off valve 71 and the second on-off valve 72. The first on-off valve 71 is provided in the air passage 46 and opens and closes the air passage 46. The second on-off valve 72 is provided in the high temperature side oil circulation path 40 (high temperature side high pressure oil path 45) between the heating section 44 and the high temperature side oil supplied section 43, and the heating section 44 and the high temperature side oil supplied section. Open and close the high-temperature side oil circulation path 40 with respect to 43. The oil and air in the heating unit 44 can pass through the first on-off valve 71 when the first on-off valve 71 is opened by the valve control unit 91, and the first on-off valve 71 is closed by the valve control unit 91. The first on-off valve 71 cannot pass. Similarly, the oil and air in the heating unit 44 can pass through the second on-off valve 72 when the second on-off valve 72 is opened by the valve control unit 91, and the second on-off valve 72 is connected to the valve control unit 91. The second on-off valve 72 cannot be passed when closed by.

  The oil circulation device 1 c includes a start timing control unit 92 that controls the start timing of the internal combustion engine 100 and a pump control unit 93 that controls the high temperature side oil pump 42. In the present embodiment, an electronic control unit (ECU) 90 functions as a valve control unit 91, a start timing control unit 92, and a pump control unit 93. The start timing control unit 92 starts the internal combustion engine 100 by, for example, cranking by a starter motor. In the fourth embodiment, the high temperature side oil pump 42 is an electric oil pump that can operate even before the internal combustion engine 100 is started.

  The pump control unit 93 starts the high temperature side oil pump 42 when the start of the internal combustion engine 100 is requested. The valve control unit 91 opens the first on-off valve 71 and closes the second on-off valve 72 until a reference time elapses after the start of the internal combustion engine 100 is requested. Thereby, the air in the heating part 44 can be discharged | emitted from the ventilation path 46 with oil. The reference time is determined in advance, and is set to, for example, a time required to discharge the air in the heating unit 44 from the air passage 46 when the most air stays in the heating unit 44.

  The start timing control unit 92 starts the internal combustion engine 100 after a reference time has elapsed since the start of the internal combustion engine 100 was requested. The valve control unit 91 closes the first on-off valve 71 and opens the second on-off valve 72 during operation of the internal combustion engine 100. Thus, after the internal combustion engine 100 is started, all the oil supplied to the heating unit 44 passes through the heating unit 44 and is supplied to the high-temperature side oil supplied unit 43, and thus the high-temperature side oil supplied unit 43. It is possible to quickly raise the temperature of the oil supplied to. In the above-described control, the second on-off valve 72 is opened during the operation of the internal combustion engine 100. For this reason, it is possible to suppress the occurrence of seizure or the like in the high temperature side oil supplied portion 43.

<Air discharge treatment>
Hereinafter, with reference to the flowchart of FIG. 11, the control for discharging the air in the heating unit 44 in the fourth embodiment will be described. FIG. 11 is a flowchart showing a control routine of air discharge processing in the fourth embodiment of the present invention. This control routine is repeatedly executed at predetermined time intervals by the ECU 90 after the start of the internal combustion engine 100 is requested.

  For example, the ECU 90 determines that the start of the internal combustion engine 100 is requested when the ignition switch of the vehicle on which the internal combustion engine 100 is mounted is turned on. The ECU 90 may determine that the start of the internal combustion engine 100 is requested when the door lock of the vehicle on which the internal combustion engine 100 is mounted is released.

  First, in step S <b> 201, the pump control unit 93 starts the high temperature side oil pump 42. Next, in step S202, the valve control unit 91 determines whether or not the elapsed time ET from the start of the high temperature side oil pump 42 is equal to or longer than the reference time Tref. If it is determined that the elapsed time ET is less than the reference time Tref, the present control routine proceeds to step S203. In step S <b> 203, the valve control unit 91 opens the first on-off valve 71 and closes the second on-off valve 72. After step S203, this control routine ends.

  On the other hand, if it is determined in step S202 that the elapsed time ET is greater than or equal to the reference time Tref, the present control routine proceeds to step S204. In step S204, the start timing control unit 92 starts the internal combustion engine 100. Next, in step S205, the valve control unit 91 closes the first on-off valve 71 and opens the second on-off valve 72. After step S205, this control routine ends.

<Fifth embodiment>
The oil circulation device for the internal combustion engine according to the fifth embodiment is basically the same as the configuration and control of the oil circulation device for the internal combustion engine according to the third embodiment, except for the points described below. For this reason, the fifth embodiment of the present invention will be described below with a focus on differences from the third embodiment.

  FIG. 12 is a diagram schematically showing the configuration of an oil circulation device 1d for an internal combustion engine according to the fifth embodiment of the present invention. The oil circulation device 1 d further includes a soak timer 95 that detects the stop time of the internal combustion engine 100. The soak timer 95 detects the stop time of the internal combustion engine 100 by measuring the time during which the ignition switch of the vehicle equipped with the internal combustion engine 100 is turned off. The soak timer 95 is built in the ECU 90, and power is directly supplied to the soak timer 95 from the battery.

  When the internal combustion engine 100 stops and oil is discharged from the high temperature side high pressure oil passage 45, air in the atmosphere gradually flows into the heating unit 44. For this reason, the longer the stop time of the internal combustion engine 100, the greater the amount of air that remains in the heating unit 44. When the amount of air in the heating unit 44 is small, the air in the heating unit 44 can be discharged by opening the on-off valve 70 for a short time. On the other hand, when the amount of air in the heating unit 44 is large, it is necessary to open the on-off valve 70 for a long time in order to exhaust the air in the heating unit 44.

  Therefore, in the fifth embodiment, the valve control unit 91 opens the on-off valve 70 until the reference time elapses after the high temperature side oil pump 42 is started, and the stop time of the internal combustion engine 100 detected by the soak timer 95 is reached. When the stop time is relatively long, the reference time is set longer than when the stop time is relatively short. As a result, it is possible to suppress the oil in the heating unit 44 from being discharged from the air passage 46 after the air has been discharged, and consequently the effect of raising the temperature of the oil in the high temperature side oil circulation path 40 is reduced. Can be suppressed.

<Air discharge treatment>
Hereinafter, with reference to the flowchart of FIG. 13, the control for discharging the air in the heating unit 44 in the fifth embodiment will be described. FIG. 13 is a flowchart showing a control routine of air discharge processing in the fifth embodiment of the present invention. This control routine is repeatedly executed at predetermined time intervals by the ECU 90 after the high temperature side oil pump 42 is started.

  First, in step S301, the valve control unit 91 acquires the stop time of the internal combustion engine 100. The stop time of the internal combustion engine 100 is detected by a soak timer 95.

  Next, in step S <b> 302, the valve control unit 91 sets a reference time Tref based on the stop time of the internal combustion engine 100. For example, the reference time Tref is set based on the stop time of the internal combustion engine 100 using a map as shown in FIG. In this map, the reference time Tref is shown as a function of the stop time of the internal combustion engine 100. As indicated by the solid line in FIG. 14, the reference time Tref is linearly increased as the stop time of the internal combustion engine 100 becomes longer. Note that the reference time Tref may be increased stepwise (stepped) as the stop time of the internal combustion engine 100 becomes longer, as indicated by a broken line in FIG.

  Next, in step S303, the valve control unit 91 determines whether or not the elapsed time ET from the start of the high temperature side oil pump 42 is equal to or longer than the reference time Tref. When it is determined that the elapsed time ET is less than the reference time Tref, the present control routine proceeds to step S304. In step S304, the valve control unit 91 opens the on-off valve 70. After step S304, this control routine ends.

  On the other hand, if it is determined in step S303 that the elapsed time ET is greater than or equal to the reference time Tref, the present control routine proceeds to step S305. In step S305, the valve control unit 91 closes the on-off valve 70. After step S305, this control routine ends.

  In the fourth embodiment, the valve control unit 91 opens the first on-off valve 71 and closes the second on-off valve 72 until the reference time elapses after the start of the internal combustion engine 100 is requested, and is detected by the soak timer 95. When the stop time of the internal combustion engine 100 is relatively long, the reference time may be set longer than when the stop time is relatively short. In this case, in the control routine shown in FIG. 11, step S301 and step S302 in FIG. 13 are executed before step S202 in FIG. In this case, the time from when the internal combustion engine 100 stops until the start of the internal combustion engine 100 is requested is the stop time of the internal combustion engine 100. In this modification of the fourth embodiment, it is possible to suppress an increase in the time from when the start of the internal combustion engine 100 is requested until the internal combustion engine 100 is started.

  The preferred embodiments according to the present invention have been described above, but the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the claims.

DESCRIPTION OF SYMBOLS 1, 1a, 1b, 1c, 1d Oil circulation device 30 Low temperature side oil circulation path 31 Low temperature side oil pan 32 Low temperature side oil pump 33 Low temperature side oil supply part 40 High temperature side oil circulation path 41 High temperature side oil pan 42 High temperature side oil Pump 43 High-temperature side oil supply part 44 Heating part 46 Ventilation path 100 Internal combustion engine

Claims (11)

A high-temperature oil pan for storing oil, a high-temperature oil pump for pumping oil from the high-temperature oil pan, a heating unit for heating the oil supplied from the high-temperature oil pan by the high-temperature oil pump, and the heating The oil heated by the unit is supplied, and a high-temperature side oil supply unit arranged in a position lower than the heating unit in the vertical direction is provided, the high-temperature side oil pan, the heating unit, and the high-temperature side oil A high temperature side oil circulation path for circulating oil between the supplied parts;
A low temperature side oil pan for storing oil, a low temperature side oil pump for pumping oil from the low temperature side oil pan, and a low temperature side oil supplied portion to which oil is supplied from the low temperature side oil pan by the low temperature side oil pump. A low-temperature side oil circulation path that circulates oil between the low-temperature side oil pan and the low-temperature side oil supplied portion;
An oil circulation device for an internal combustion engine, comprising: an air passage connected to the heating unit and configured to exhaust air in the heating unit.   The oil circulation device for an internal combustion engine according to claim 1, wherein the air passage is connected to an uppermost portion of the heating unit.   3. The oil circulation device for an internal combustion engine according to claim 1, wherein the air passage is connected to the low-temperature-side oil-supplied portion disposed at a position higher than the heating portion in the vertical direction.   3. The oil circulation device for an internal combustion engine according to claim 1, wherein the air passage is connected to the high temperature side oil supplied portion. The air passage is configured to return a part of the oil in the heating unit to the high temperature oil pan,
The oil circulation device further includes an on-off valve that opens and closes the air passage, and a valve control unit that controls the on-off valve,
3. The oil circulation device for an internal combustion engine according to claim 1, wherein the valve control unit temporarily opens the on-off valve after the high temperature side oil pump is started.   6. The oil circulation device for an internal combustion engine according to claim 5, wherein the valve control unit opens the on-off valve until a reference time elapses after the high temperature side oil pump is started. The air passage is configured to return a part of the oil in the heating unit to the high temperature oil pan,
The oil circulation device includes: a first on-off valve that opens and closes the ventilation path; a second on-off valve that opens and closes the high-temperature side oil circulation path between the heating unit and the high-temperature side oil supplied part; A valve control unit for controlling the one on-off valve and the second on-off valve, a start timing control unit for controlling the start timing of the internal combustion engine, and a pump control unit for controlling the high temperature side oil pump,
The pump control unit starts the high temperature side oil pump when the start of the internal combustion engine is requested, and the valve control unit performs the first operation until a reference time elapses after the start of the internal combustion engine is requested. One open / close valve is opened and the second open / close valve is closed, and the first open / close valve is closed and the second open / close valve is opened during operation of the internal combustion engine. The oil circulation device for an internal combustion engine according to claim 1 or 2, wherein the internal combustion engine is started after the reference time has elapsed since the request was made. A soak timer for detecting a stop time of the internal combustion engine;
The valve control unit makes the reference time longer when the stop time of the internal combustion engine detected by the soak timer is relatively longer than when the stop time is relatively short. An oil circulation device for an internal combustion engine according to claim 7.   The oil circulation device for an internal combustion engine according to any one of claims 1 to 8, wherein the heating unit includes a heating oil passage formed around an exhaust port.   The oil circulation device for an internal combustion engine according to claim 9, wherein the heating oil passage has a protruding portion protruding upward in the vertical direction, and the ventilation passage is connected to a top portion of the protruding portion.   The oil circulation device for an internal combustion engine according to any one of claims 1 to 10, wherein the high temperature side oil supplied portion includes a crank journal.

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