Internal Combustion Engine for a Motor Vehicle, Motor Vehicle, and Method

Abstract

An internal combustion engine for a motor vehicle includes a crankcase. The crankcase has having at least two oil separation devices and having a return device. The return device has at least one first return channel that is flowable through by a first portion of the oil separated from the blow-by gas with a first of the oil separation devices, through which the first portion of the separated oil is guided from the first oil separation device into the reservoir. The return device also has at least one second return channel that is at least partially spaced apart from the first return channel and is flowable through by a second portion of the oil separated from the blow-by gas via the second oil separation device, through which second return channel the second portion of the separated oil is guided from the second oil separation device into the reservoir.

Claims

1.-10. (canceled)

11. An internal combustion engine for a motor vehicle, comprising: a crankcase, having at least two oil separation devices, via which oil is separable from blow-by gas discharged from the crankcase and is fed to the oil separation devices, and having a return device, through which the oil separated via the oil separation devices flows, via which oil separation device the oil separated from the blow-by gas via the oil separation devices is guided from the oil separation devices into a reservoir, wherein the return device has at least one first return channel that is flowable through by a first portion of the oil separated from the blow-by gas with a first of the oil separation devices, through which the first portion of the separated oil is guided from the first oil separation device into the reservoir, and at least one second return channel that is at least partially spaced apart from the first return channel and is flowable through by a second portion of the oil separated from the blow-by gas via the second oil separation device, through which second return channel the second portion of the separated oil is guided from the second oil separation device into the reservoir.

12. The internal combustion engine according to claim 11, wherein the oil separation devices are each spaced apart from the reservoir at a same distance in the vertical direction of the vehicle.

13. The internal combustion engine according to claim 12, wherein the return channels each have at least one length section through which the oil flows and which runs within a housing wall of the crankcase, which length section is delimited at least partially in its circumferential direction by the housing wall.

14. The internal combustion engine according to claim 13, wherein respective opening points at which the return channels open into a receiving area in which the oil is received which is delimited by the reservoir.

15. The internal combustion engine according to claim 14, wherein at least one of the opening points is arranged below an oil level of the oil located in the reservoir in the vertical direction of the vehicle.

16. The internal combustion engine according to claim 15, wherein the oil separation devices are arranged in a cylinder head cover which is arranged above a cylinder head of the internal combustion engine in the vertical direction of the vehicle.

17. The internal combustion engine according to claim 16, wherein the return channels each have at least one second length section, through which the oil flows and which is arranged upstream of the respective length section in the flow direction of the oil flowing through the return channels, the second length section running within the cylinder head, wherein the second length section is delimited at least partially in its circumferential direction by the cylinder head.

18. The internal combustion engine according to claim 17, wherein the respective return channel is produced via drilling and/or via casting.

19. A motor vehicle having an internal combustion engine according to claim 18.

20. A method for operating an internal combustion engine according to claim 18.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1 shows a schematic partial sectional view of an internal combustion engine in a perspective view;

[0032] FIG. 2 shows a schematic partial sectional view of an internal combustion engine in a side perspective view;

[0033] FIG. 3 shows a schematic partial sectional view of an internal combustion engine in a front perspective view; and

[0034] FIG. 4 shows a schematic partial sectional view of an internal combustion engine in a front perspective view.

DETAILED DESCRIPTION

[0035] In the figures, identical or functionally identical elements are provided with the same reference signs.

[0036] FIG. 1 shows a schematic partial sectional view of an internal combustion engine 1 for a motor vehicle 2 in a perspective view, and FIG. 2 shows a schematic partial sectional view of the internal combustion engine 1 in a side perspective view, and FIG. 3 shows a schematic partial sectional view of the internal combustion engine 1 in a front perspective view. The motor vehicle 2 is preferably in the form of an automobile, in particular a passenger vehicle, commercial vehicle, or truck. The internal combustion engine 1 comprises an output shaft, in particular designed as a crankshaft, via which the motor vehicle 2 can be driven by the internal combustion engine 1.

[0037] The internal combustion engine 1 has at least one crankcase 3, particularly referred to as a cylinder crankcase, which at least partially delimits at least one cylinder 4 and a crankcase chamber 5 of the internal combustion engine 1, wherein the internal combustion engine 1 shown in the exemplary embodiment comprises six cylinders 4. The respective cylinder 4 has a cylinder wall 6 in each case, which partially delimits a combustion chamber 7 in each case. A piston is arranged in each cylinder 4 and is translationally movable relative to the cylinder wall 6. The internal combustion engine 1 has an intake tract through which air can flow and an exhaust tract through which the exhaust gas from the combustion chamber 7 can flow. The air, particularly referred to as fresh air, can be supplied to the combustion chamber 7 via the intake tract, and the exhaust gas from the combustion chamber 7 can be discharged via the exhaust tract. When the internal combustion engine is in an activated state, combustion processes, particularly referred to as combustion, take place in the respective combustion chamber 7, wherein a fuel-air mixture comprising fresh air is combusted, resulting in the exhaust gas from the internal combustion engine 1.

[0038] Particularly when the internal combustion engine 1 is in the activated state, a gas, in particular exhaust gas, can enter the crankcase 3 or crankcase chamber 5 from the respective combustion chamber 7, particularly through a gap formed at least partially by the respective piston and the respective cylinder wall 6, wherein the gas that enters the crankcase 3 or crankcase 5 from the respective combustion chamber 7 and is located in the crankcase chamber 5 can be referred to as blow-by gas. The internal combustion engine 1 has at least two oil separation devices 8, 9, which are particularly designed to be separate from one another, by means of which oil can be separated from the blow-by gas discharged from the crankcase 3 or crankcase chamber 5 and fed to the oil separation devices 8, 9. The oil separation devices 8, 9 are schematically depicted in FIGS. 1 and 3. The internal combustion engine 1 comprises a return device 10 through which the oil separated by means of the oil separation devices 8, 9 can flow, via which oil separation device the oil separated from the blow-by gas by means of the oil separation devices 8, 9 can be guided or introduced from the oil separation devices 8, 9 into a reservoir 11. The reservoir 11 may, in particular, be designed as an oil pan, provided for collecting the oil. The reservoir 11 is preferably arranged with the internal combustion engine in the installed position in the vertical direction of the vehicle 12 below the oil separation devices 8, 9 in the crankcase 3 or the crankcase chamber 5 or below the crankcase 3 in the vertical direction of the vehicle 12. In its fully manufactured state, the internal combustion engine 1 assumes the installed position in the motor vehicle 2 in a fully manufactured state of the vehicle 2. The reservoir 11 is shown in FIG. 4, which depicts a schematic partial sectional view of the internal combustion engine 1 in a front perspective view. In a designated flow direction 12a, the oil flowing through the return device 10 flows from the respective oil separation device 8, 9 to the reservoir 11.

[0039] So that the oil can be separated from the blow-by gas particularly advantageously, the return device 10 has at least one first return channel 14 that can be flowed through by a first portion 13 of the oil separated from the blow-by gas by means of a first of the oil separation devices 8, through which the first portion 13 of the separated oil can be guided from the first oil separation device 8 into the reservoir 11, and at least one second return channel 16 that is at least partially spaced apart from the first return channel 14 and can be flowed through by a second portion 15 of the oil separated from the blow-by gas by means of a second of the oil separation devices 9, through which the second portion 15 of the separated oil can be guided from the second oil separation device 9 into the reservoir 11.

[0040] As a result, a respective geodetic height difference or a respective distance 17, 18 in the vertical direction of the vehicle 12 between the respective oil separation device 8, 9 and the reservoir 11 can be particularly increased. The respective distance 17, 18 runs in the vertical direction of the vehicle 12, for example, between a respective first point 8a, 9a of the respective oil separation device 8, 9 and a second point 11a of the reservoir 11. The respective first point 8a, 9a is arranged, for example, in a respective outlet opening of the respective oil separation device 8, 9, for example, and the second point 11a is arranged in the reservoir 11. The respective oil separation device 8, 9 is fluidically connected to the return device 10 via the respective outlet opening. The respective first point 8a, 9a in this case is preferably a lowest point of the respective outlet opening in the vertical direction of the vehicle 12. The fact that the respective distance 17, 18 can be particularly increased means that a respective pressure loss potential of the respective oil separation device 8, 9 can be particularly increased. This means, on the one hand, that a filtration efficiency of the respective oil separation device 8, 9 can be particularly increased and, on the other hand, it is possible to prevent oil located in the reservoir 11 from flowing upwards through the return device 10, in particular the respective return channel 14, 16, in the vertical direction of the vehicle 12 and therefore against the intended flow direction 12a to the respective oil separation device 8, 9. In this way, the filtration efficiency of the respective oil separation device 8, 9 can be particularly increased and an introduction of returned oil into the intake tract can be avoided, as a result of which noxious emissions from the internal combustion engine 1 can be kept particularly low.

[0041] In the installed position of the internal combustion engine 1 in the motor vehicle 2, the oil separation devices 8, 9 are preferably spaced at equal distances from the reservoir 11 in the vertical direction of the vehicle 12. In other words, a first of the distances 17 between the first oil separation device 8 and the reservoir 11 is the same as the second of the distances 18 between the second oil separation device 9 and the reservoir 11. In this way, both geodetic height differences or both distances 17, 18 can be particularly increased, enabling both oil separation devices 8, 9 to have a particularly high pressure loss potential.

[0042] In a further embodiment, the return channels 14, 16 each have at least one length section 20, 21 through which the oil can flow and which runs within a housing wall 19 of the crankcase 3, which length section 20, 21 is delimited at least partially, in particular completely circumferentially, in its respective circumferential direction 22, 23 by the housing wall 19, in particular directly. The first return channel 14, or the length section 20, 21 of the first return channel 14, is arranged on the inlet side in the crankcase 3. The second return channel 16, or the length section 20, 21 of the second return channel 16, is arranged on the inlet side in the crankcase 3. Arrangement on the inlet side or on the outlet side can, in particular, be understood to mean the following: With respect to an imaginary center plane of the cylinders 4 extending in the vertical direction of the vehicle 12 and in the longitudinal direction of the output shaft, a first side of the center plane can be referred to as the inlet side, wherein the air flowing through the intake tract is guided to the combustion chambers 7 via the first side and a second side of the center plane lying opposite the first side can be referred to as the outlet side, wherein the exhaust gas flowing through the exhaust tract is discharged from the combustion chambers 7 via the second side. The partial sectional view shown in FIG. 2 is a partial sectional view on the inlet side.

[0043] The first oil separation device 8 is preferably designed as a part-load oil separator, and the second oil separation device 9 is designed as a full-load oil separator. This means that the first return channel 14 is referred to as a part-load separation channel, and the second return channel 16 is referred to as a full-load separation channel.

[0044] The internal combustion engine 1 comprises a cylinder head 25, which is arranged above the crankcase 3 when the internal combustion engine 1 is in the installed position in the motor vehicle 2. The oil separation devices 8, 9 are preferably arranged in a cylinder head cover 24 which is arranged above the cylinder head 25 of the internal combustion engine 1 in the vertical direction of the vehicle 12 when the internal combustion engine 1 is in the installed position in the motor vehicle 2. The cylinder head cover 24 may, in particular, be referred to as a valve cover and delimit the cylinder head 25 upwards in the vertical direction of the vehicle 12 at least partially, in particular directly. Furthermore, the return channels 14, 16 each have at least one second length section 26, 27 through which the oil can flow and which is arranged upstream of the respective length section 20, 21 in the flow direction 12a of the oil flowing through the return channels 14, 16, which second length section 26, 27 runs within the cylinder head 25, wherein the second length section 26, 27 in each case is delimited at least partially, in particular completely circumferentially, in its respective circumferential direction 28, 29 by the cylinder head 25, in particular directly. This allows the oil to be guided from the respective oil separation device 8, 9 through the cylinder head 25 and the crankcase 3 into the reservoir 11, wherein, in particular, the fact that the oil separation devices 8, 9 are arranged in the cylinder head cover 24 means that the distances 17, 18 can be particularly increased.

[0045] In a further embodiment, the internal combustion engine 1 comprises opening points 30, 31 in each case, at which the return channels 14, 16 open into at least one receiving area 32 directly bounded by the reservoir 11, in which the oil can be received. This allows the oil flowing through the return channels 14, 16 to be discharged from, or directed out of, the respective return channel 14, 16 via the respective opening points 30, 31 and introduced into the reservoir 11 or the receiving area 32. The opening points 30, 31 are schematically depicted by way of example in FIG. 4. The return channels 14, 16 preferably each have at least one third length section 33, through which the oil can flow and which is arranged downstream of the respective length section 20, 21 in the flow direction 12a of the oil flowing through the return channels 14, 16, which third length section 33 runs within a reservoir wall 34 of the reservoir 11, wherein the third length section 33 is at least partially, in particular completely, delimited by the reservoir wall 34, in particular directly, in its circumferential direction.

[0046] In a further embodiment, when the internal combustion engine 1 is in the installed position in the motor vehicle 2, at least one of the opening points 30, 31 is arranged below an oil level 35, particularly referred to as the desired oil level, of the oil located in the reservoir 11. This allows the reservoir 11 to function as a siphon, particularly referred to as an oil siphon, eliminating the need for a corresponding oil siphon designed to be separate from the reservoir 11, wherein the oil collected in the reservoir 11 can flow out of the reservoir 11, for example when a defined fill level of the reservoir 11 is exceeded, particularly downwards to the side or and downwards to the side in the vertical direction of the vehicle. In other words, the oil siphon can be placed into the reservoir 11. Again, in other words, the third length section 33 can lengthen the respective return channel 14, 16 in the vertical direction of the vehicle 12 to below the oil level 35. Alternatively, at least one of the opening points 30, 31 may be arranged above the oil level 35 when the internal combustion engine 1 is in the installed position in the vertical direction of the vehicle 12.

[0047] The respective return channel 14, 16, in particular at least one of the respective length sections 20, 21, 26, 27, 33, is preferably produced by means of drilling and/or by means of casting. This allows the internal combustion engine 1, in particular the respective return channel 14, 16, to be produced particularly advantageously and particularly cost-effectively. In at least one of the respective return channels 14, 16, particularly in the respective length section 20, 21, there may be arranged at least one valve device 36, particularly referred to as a check valve, by means of which a respective mass flow of the oil flowing through the respective return channel 14, 16 can be adjusted. In this way, for example, a return flow of oil running from the reservoir 11 through the respective return channel 14, 16 to the respective oil separation device 8, 9, which would run against the flow direction 12a, can be particularly advantageously avoided.

LIST OF REFERENCE SIGNS

[0048] 1 internal combustion engine [0049] 2 motor vehicle [0050] 3 crankcase [0051] 4 cylinder [0052] 5 crankcase chamber [0053] 6 cylinder wall [0054] 7 combustion chamber [0055] 8 first oil separation device [0056] 8a first point [0057] 9 second oil separation device [0058] 9a first point [0059] 10 return device [0060] 11 reservoir [0061] 11a second point [0062] 12 vertical direction of the vehicle [0063] 12a flow direction [0064] 13 first portion [0065] 14 first return channel [0066] 15 second portion [0067] 16 second return channel [0068] 17 first distance [0069] 18 second distance [0070] 19 housing wall [0071] 20 length section [0072] 21 length section [0073] 22 circumferential direction [0074] 23 circumferential direction [0075] 24 cylinder head cover [0076] 25 cylinder head [0077] 26 second length section [0078] 27 second length section [0079] 28 circumferential direction [0080] 29 circumferential direction [0081] 30 first opening point [0082] 31 second opening point [0083] 32 receiving area [0084] 33 third length section [0085] 34 reservoir wall [0086] 35 oil level [0087] 36 valve device