Internal combustion engine for a motor vehicle, motor vehicle and method

Abstract

The present invention relates to an internal combustion engine (1) for a motor vehicle (2), comprising: a crankcase (3); at least two oil separators (8, 9) by means of which oil can be separated from leaking gas; and a return device (10) through which the separated oil can be guided from the oil separators (8, 9) to a storage tank (11), wherein the return device (10) has at least one oil that can be separated by means of a first oil separator (8). The first part (13) flows through a first return channel (14) and at least one second return channel (16) at least partially spaced from the first return channel (14) and through which the second part (15) can be separated by the second oil separator (9), through which the first part (13) can be guided from the first oil separator (8) into the storage tank (11), and through the second return channel can be guided from the second oil separator (9) into the storage tank (11).

Description

Technical Field

[0001] This invention relates to an internal combustion engine for a motor vehicle. Furthermore, this invention relates to a motor vehicle and a method for operating the internal combustion engine of the motor vehicle. Background Technology

[0002] EP 3 020 934 B1 discloses a vehicle with an internal combustion engine having a crankcase and a supercharger, and a crankcase ventilation device having at least one inertial oil separator including at least one inertial oil separator, an oil return device for guiding separated oil back to the crankcase, and a suction jet pump driven by compressed air from the supercharger and generating negative pressure to drive leaking gas. The crankcase ventilation device includes a pump control valve that regulates and / or controls the flow of compressed air through the suction jet pump, and the pump control valve has a loss portion arranged to apply a force to a valve seat, and to overcome the force and lift from the valve seat when a threshold pressure difference between the valve inlet and outlet is exceeded, or when a threshold pressure on the inlet side is exceeded, thereby opening the pump control valve.

[0003] Furthermore, EP 3 034 820 A2 discloses an exhaust device for discharging blow-by gases from the engine block of an internal combustion engine. This device has a first inlet opening for introducing the blow-by gases from the engine block into an exhaust gas device and a second inlet opening spaced apart from the first inlet opening, and at least one oil separator for separating oil from the blow-by gases. The exhaust device includes: a first supply passage for supplying blow-by gases to the at least one oil separator, wherein the first supply passage extends from the first inlet opening to such an oil separator; and a second supply passage for supplying blow-by gases to the at least one oil separator, wherein the second supply passage extends from the second inlet opening to a connection point located upstream of the at least one oil separator in the first supply passage. Summary of the Invention

[0004] The object of the present invention is to provide an internal combustion engine for a motor vehicle, a motor vehicle having such an internal combustion engine, and a method for operating such an internal combustion engine, such that oil can be advantageously separated from the blow-through gases of the internal combustion engine.

[0005] According to the invention, this objective is achieved by an internal combustion engine for a motor vehicle, by a motor vehicle having such an internal combustion engine, and by a method for operating such an internal combustion engine in such a motor vehicle. Advantageous embodiments are the subject of the dependent claims and the description.

[0006] A first aspect of the invention relates to an internal combustion engine for a motor vehicle, preferably configured as an automobile, particularly as a passenger car, commercial vehicle, or truck. The internal combustion engine has an output shaft, particularly configured as a crankshaft, through which the motor vehicle can be driven by the internal combustion engine. The internal combustion engine includes a crankcase, particularly called a cylinder crankcase, which at least partially defines at least one cylinder and crankshaft chamber of the internal combustion engine. The output shaft is at least partially arranged inside the crankcase and thus within the crankshaft chamber, wherein the output shaft is rotatable relative to the crankcase.

[0007] Preferably, the piston is arranged in the cylinder in a manner translatably relative to the cylinder wall. The cylinder wall may be formed by a crankcase. The cylinder wall and piston partially define the combustion chamber of the internal combustion engine. The internal combustion engine has an intake manifold through which air flows and an exhaust manifold through which exhaust gases flow. Air can be supplied to the combustion chamber through the intake manifold, and exhaust gases can be discharged from the combustion chamber through the exhaust manifold. The air flowing through the intake manifold may be specifically referred to as fresh air. At least one compressor may be arranged in the intake manifold, by which the air flowing through the intake manifold can be compressed and delivered to the combustion chamber. Preferably, the internal combustion engine has a cylinder head that partially defines the combustion chamber. An inlet passage through which air flows may extend within the cylinder head, the inlet passage being part of the intake manifold, wherein air flowing through the inlet passage can be supplied to the combustion chamber. In other words, the intake manifold may extend at least partially within the cylinder head, such that air flowing through the intake manifold can pass through the cylinder head via the inlet passage. When an internal combustion engine is in an active state, a combustion process occurs in the combustion chamber, during which a fuel-air mixture containing fresh air is burned, thereby producing exhaust gases from the internal combustion engine. This combustion process can be specifically referred to as combustion.

[0008] An internal combustion engine has at least two oil separators, particularly separately constructed, by which oil is separated from blow-by gases discharged from the crankcase, particularly the crankshaft chamber, and supplied to the oil separators. The oil separators may be specifically referred to as oil separators or oil mist separators. Blow-by gases can be understood in particular as exhaust gases arriving from or flowing into the crankcase, particularly the crankshaft chamber, particularly through a gap formed at least partially by the piston or at least one piston ring arranged on the piston and the cylinder wall. The blow-by gases may include the oil, which can be removed from the blow-by gases, for example, as the blow-by gases flow from the combustion chamber into the crankshaft chamber. Here, oil that can, for example, wet the cylinder walls and / or piston rings, can be entrained by the blow-by gases as they flow through the gap, thus the oil can be received by the blow-by gases. Furthermore, oil may be provided, for example, for lubricating bearings in the crankcase or crankshaft chamber, particularly the output shaft, and here it is received by the blow-by gases in the crankshaft chamber. In particular, since the blow-by gases may include oil, they may be specifically referred to as oil mist. Expelling leaking gases from the crankcase or separating oil from leaking gases can be specifically referred to as crankcase venting. For example, leaking gases can be discharged from the crankcase through piping components and supplied to an oil separator.

[0009] Preferably, one of the oil separation devices is configured as a full-load oil separator, while the other is preferably configured as a partial-load oil separator. This can be understood in particular as follows: in the internal combustion engine's operating state, referred to as full load, oil is separated or separable from the blow-by gas via the full-load oil separator, wherein separation of oil from the blow-by gas via the partial-load oil separator is preferably avoided; and in the internal combustion engine's operating state, different from full load and referred to as partial load, oil is separated or separable from the blow-by gas via the partial-load oil separator, wherein separation of oil from the blow-by gas via the full-load oil separator is preferably avoided. For example, in the operating state referred to as full load, the torque of the internal combustion engine or output shaft can be particularly high, and for example, corresponds to the maximum torque of the internal combustion engine. In the operating state referred to as partial load, the torque of the internal combustion engine or output shaft can be particularly low, particularly less than the torque at full load, and for example, less than 50% of the maximum torque of the internal combustion engine.

[0010] When oil is separated from leaking gas by an oil separator, the leaking gas flows through the corresponding oil separator, thereby separating oil from the leaking gas through the corresponding oil separator, and thus the leaking gas is cleaned of oil by the corresponding oil separator and is therefore preferably oil-free after separation. The leaking gas, with oil removed by the oil separator during oil separation, can be supplied to the intake manifold after separation, thereby being introduced into the intake manifold. At full load, the leaking gas is preferably introduced into the intake manifold upstream of the compressor in the direction of air flow through the intake manifold after oil separation by a full-load oil separator. At partial load, the leaking gas is preferably introduced into the intake manifold downstream of the compressor, particularly into the inlet passage, in the direction of air flow through the intake manifold after oil separation by a partial-load oil separator.

[0011] The internal combustion engine includes a return device through which oil separated by an oil separator flows, through which oil separated from leaking gases by the oil separator can be guided from the oil separator to or introduced into a storage tank. The storage tank is preferably constructed with an oil sump for collecting the oil. The oil sump may be specifically referred to as an oil pool. Preferably, the storage tank is arranged below the oil separator in the vehicle height direction in the mounting position of the internal combustion engine, wherein the internal combustion engine occupies the mounting position in the fully manufactured state of the motor vehicle. For example, the storage tank may be arranged below the crankcase or within the crankcase or crankcase chamber in the vehicle height direction in the mounting position of the internal combustion engine.

[0012] To enable particularly advantageous separation of oil from leaking gas, the reflux device comprises: at least one first reflux channel through which a first portion of oil separated from the leaking gas by means of a first oil separator flows, through which the separated first portion of oil is guided from the first oil separator to a storage tank; and at least one second reflux channel, at least partially spaced from the first reflux channel, through which a second portion of oil separated from the leaking gas by means of a second oil separator flows, through which the separated second portion of oil is guided from the second oil separator to a storage tank. In other words, the reflux device includes reflux channels that are at least partially separated from each other, particularly constructed separately, wherein the first oil separator is fluidly connected to the storage tank via the first reflux channel, and the second oil separator is fluidly connected to the storage tank via the second reflux channel, thereby allowing the first portion of oil to be introduced into the storage tank through the first reflux channel, and the second portion of oil to be introduced into the storage tank through the second reflux channel. The return channel provided to the full-load oil separator may be specifically referred to as the full-load separation channel, and the return channel provided to the partial-load oil separator may be specifically referred to as the partial-load separation channel.

[0013] This invention is based in particular on the understanding and consideration that the filtration efficiency of a corresponding oil separator can be directly dependent (observed along the oil flow direction) on the pressure loss via the oil separator, specifically referred to as the pressure loss potential. Pressure loss can be understood in particular as the pressure difference between two pressures, particularly the hydrostatic pressure difference, where the first pressure can be the oil pressure in the oil separator, and the second pressure can be the oil pressure in the return device or storage tank. Filtration efficiency can be understood in particular as the efficiency of separating oil by means of the corresponding oil separator, particularly the separation efficiency. Generally, particularly high filtration efficiency can be achieved with particularly high pressure loss. Furthermore, particularly high robustness against oil entrainment can be achieved with particularly high pressure loss. Oil entrainment can be understood in particular as oil reaching the separation chamber of the corresponding oil separator and / or even the intake duct in the vehicle height direction, specifically in the direction of air flow through the intake duct, against the initial flow direction of the oil flowing through the return device, via a return device specifically referred to as the return channel, reaching the upstream and / or inlet channel of the compressor. If oil can reach the oil separator upwards in the vehicle height direction, then the filtration efficiency of the oil separator, for example, will decrease significantly. In particular, when oil can reach the intake manifold, it can travel through the intake manifold to the combustion chamber and participate in the combustion process or be burned there, which may significantly increase the pollutant emissions of the internal combustion engine.

[0014] In conventional internal combustion engines, the return system may have exactly one return channel through which the first and second portions of the separated oil are guided from the respective oil separator to a storage tank. In other words, in conventional internal combustion engines, two oil separators may share a common return channel. Here, particularly due to structural space constraints, one oil separator is arranged below the other in the vehicle height direction; for example, a partial-load oil separator may be arranged below a full-load oil separator in the vehicle height direction. Therefore, the geodesic height difference, particularly the one located below in the vehicle height direction, between the respective oil separator and the storage tank can be particularly small. The geodesic height difference can be understood here as the distance between two points extending in the vehicle height direction, where the first point may be arranged, for example, in the corresponding outlet opening of the respective oil separator, and the second point may be arranged in the storage tank. The respective oil separator is fluidly connected to the return system through the corresponding outlet opening. Here, the first point is preferably the lowest point of the outlet opening in the vehicle height direction. For example, the second point is the highest point of the storage tank in the vehicle height direction. Due to the extremely small geodesic height difference, the pressure loss potential and thus filtration efficiency of the corresponding oil separator in a conventional internal combustion engine may be particularly low. Because of the extremely small geodesic height difference, the engine's mounting position in the vehicle, and, when necessary, the extremely rapid turning of the vehicle, the geodesic height difference may no longer be sufficient to force oil upwards into the oil separator, particularly into the separator chamber, or even into the intake manifold, against the initial flow direction of the oil, in the vehicle's height direction via a return flow device.

[0015] Conversely, in the internal combustion engine according to the invention, particularly due to the significant geodesic height difference or spacing between the two return channels, oil can be cleanly guided downwards along the vehicle's height direction into the reservoir under all driving conditions of the vehicle, especially during cornering, even under particularly high lateral acceleration, and from there cannot reach the oil separator upwards along the vehicle's height direction. This geodesic height difference significantly increases the pressure loss potential, thereby significantly increasing the filtration efficiency of the corresponding oil separator. In other words, the oil separator can be arranged particularly high in the vehicle's height direction within the internal combustion engine, and therefore offset particularly far upwards relative to a conventional internal combustion engine, thereby significantly increasing the geodesic height difference or spacing.

[0016] In another embodiment of the invention, the internal combustion engine includes a reservoir, and in the installation position of the internal combustion engine, oil separators are spaced equidistantly from the reservoir in the vehicle height direction. This can be understood in particular as corresponding first points and second points of the respective oil separators being spaced equidistantly in the vehicle height direction. Therefore, the two oil separators have the same geodesic height difference or the same value of the geodesic height difference, thereby significantly increasing the pressure loss potential of the two oil separators. Since the internal combustion engine according to the invention includes a reservoir in this embodiment, the reservoir is part of the protection scope of the internal combustion engine according to the invention.

[0017] In another embodiment of the invention, the return channel has at least one length region through which oil can flow and extends within the crankcase housing wall, this length region being at least partially, and particularly completely, circumferentially bounded by the housing wall, especially directly, in its circumferential direction. In other words, two portions of the oil pass through the crankcase housing wall via corresponding length regions of the return channel. Again, in other words, oil discharged from the corresponding oil separator, particularly at the cylinder head interface, can be received by the corresponding return channel and thus guided downward through the crankcase in the vehicle height direction to a reservoir. Therefore, oil separated from leaking gases by the oil separator can be advantageously guided from the oil separator to the reservoir, thereby keeping, for example, the manufacturing cost or expense of the internal combustion engine and / or the structural space of the internal combustion engine at a particularly low level.

[0018] In another embodiment, the internal combustion engine includes a corresponding manifold at which a return passage merges into at least one receiving area, specifically directly defined by a storage tank, where oil can be received. In other words, oil flowing through a corresponding return passage can be discharged or discharged from the corresponding return passage through the corresponding manifold and can be introduced into the storage tank, wherein the corresponding return passage is fluidly connected to the receiving area via the corresponding manifold. Therefore, oil flowing through the return passage can be advantageously introduced into the storage tank.

[0019] In another embodiment, at least one manifold is arranged in the vehicle height direction at the internal combustion engine mounting position below the oil level, specifically referred to as the oil level, of the oil in the reservoir. In other words, particularly when the vehicle is stationary and / or on a level road and / or the internal combustion engine is inactive and / or the oil received in the receiving area or reservoir has a temperature of 25°C and / or the internal combustion engine has a defined oil quantity, specifically referred to as the target oil quantity (which is set for normal operation of the internal combustion engine in its fully operational state), at least one manifold is arranged in the vehicle height direction at the internal combustion engine mounting position below the oil level, specifically referred to as the target oil level. The vehicle being stationary can be specifically understood as the vehicle not moving and therefore not moving relative to the road. A level road can be specifically understood as the road not being inclined, i.e., having no incline. The inactive state of the internal combustion engine is an operating state of the internal combustion engine different from its active state, wherein the combustion process in the combustion chamber ceases in the inactive state.

[0020] In conventional internal combustion engines, an oil siphon, through which oil can flow, can be arranged between the oil separator and the reservoir, for example, in the cylinder head, in the direction of oil flow from the corresponding oil separator to the reservoir. For example, the oil siphon has at least one curved section in which oil can be collected, and the oil collected in this section, especially when exceeding the fill height of this section, can flow out of that section, thereby being discharged from the oil siphon and directed to a return device, for example. In conventional internal combustion engines, the oil siphon can be arranged, particularly directly on the oil separator, and is often referred to as a "bird's drinker." The oil siphon can have a function, particularly a sealing function, because the oil siphon may be airtight due to the oil located there. In conventional internal combustion engines, the second geodesic height difference or second distance between the oil siphon and the corresponding oil separator may be particularly small in the vehicle height direction, thereby resulting in a particularly low pressure loss potential and consequently a particularly low filtration efficiency of the corresponding oil separator. Since at least one manifold in the internal combustion engine according to the invention is arranged below the oil level in the oil pan in the vehicle height direction during the engine's installation position, the oil siphon of a conventional internal combustion engine can be eliminated, as the reservoir, particularly the oil pan, can perform the function of a conventional oil siphon. In other words, the position of the oil siphon can be shifted downwards in the vehicle height direction, particularly relative to a conventional internal combustion engine, thereby significantly increasing the second gap or second geodesic height difference. Here, the geodesic height difference can correspond to a second geodesic height difference. Therefore, for example, the filtration efficiency or pressure loss potential can be significantly increased.

[0021] For example, the corresponding return channel may extend at least partially within the tank wall, which at least partially defines the tank, and is guided below the target oil level in the vehicle height direction. Thus, the corresponding return channel, or the oil flowing through it, may communicate with the interior of the tank, specifically referred to as the bottom sump, below the target oil level in the vehicle height direction. Alternatively, in the internal combustion engine mounting location, at least one manifold may be arranged above the oil level in the oil pan in the vehicle height direction.

[0022] In another embodiment, the oil separator is arranged within a cylinder head cover, which, in the vehicle height direction, is positioned above the cylinder head of the internal combustion engine in its mounting location. In other words, the oil separator is at least partially surrounded by the cylinder head cover. The cylinder head is positioned above the crankcase in the vehicle height direction and, at least partially and directly, defines the crankcase upwards in that direction. The cylinder head cover may be specifically referred to as a valve cover and, at least partially and directly, defines the cylinder head upwards in the vehicle height direction. Because the oil separator is arranged within the cylinder head cover, the geodesic height difference or spacing can be significantly increased, thereby significantly increasing the pressure loss potential.

[0023] In another embodiment, each return channel has at least one second length region arranged upstream of the corresponding length region in the flow direction of the oil passing through the return channel, which is permissible by oil flow. This second length region extends within the cylinder head, wherein the second length region is at least partially, and particularly completely, circumferentially bounded by the cylinder head, especially directly, in its circumferential direction. In other words, at least the corresponding second length region of the return channel is arranged in the cylinder head, so that two portions of the oil can be guided from the corresponding oil separator through the cylinder head to or into the reservoir. Thus, the two portions of the oil from the corresponding oil separator can be guided from the cylinder head cover, through the cylinder head, through the crankcase, all the way to the reservoir.

[0024] In another embodiment, the corresponding reflux channel is formed by drilling and / or by casting. In other words, the corresponding length region and / or the corresponding second length region are formed by drilling and thus implemented as corresponding holes and / or formed by casting and thus cast. Again, in other words, the corresponding reflux channel can be machined by drilling and / or the corresponding reflux channel can be cast. The manufacture of the corresponding reflux channel implemented as a hole can be, for example, by two intersecting holes, wherein the first hole can start from the cylinder head, which can be specifically referred to as a hole from the cover surface, and the second hole can start from the tank side, which can be specifically referred to as a hole from the tank side or the oil pan side. The casting of the corresponding reflux channel is preferably carried out by at least one core. The corresponding reflux channel can be manufactured particularly cost-effectively and / or with particular precision by drilling or by casting. The corresponding cross-section of the reflux channel can be implemented in different sizes according to needs and production possibilities. At least one sealing element can be installed between the tank and the crankcase, particularly the shell wall. In other words, a sealing element can be arranged between the tank and the crankcase, particularly the shell wall, through which the tank or the corresponding reflux passage can be kept in a particularly sealed manner.

[0025] The second aspect of the invention relates to a motor vehicle having an internal combustion engine according to the invention according to the first aspect. The advantages and advantageous embodiments of the first aspect of the invention should be regarded as advantages and advantageous embodiments of the second aspect of the invention, and vice versa. The motor vehicle according to the invention is preferably constructed as an automobile, particularly as a passenger car, commercial vehicle, or truck, or as a bus or motorcycle.

[0026] A third aspect of the invention relates to a method for operating an internal combustion engine for a motor vehicle according to a first aspect of the invention, said internal combustion engine having a crankcase and at least two oil separators constructed separately from each other. The advantages and advantageous embodiments of the first and second aspects of the invention should be regarded as advantages and advantageous embodiments of the third aspect of the invention, and vice versa.

[0027] In the method according to the invention, oil is separated from the blow-through gas discharged from the crankcase and supplied to the oil separator by an oil separator, and the oil separated from the blow-through gas by the oil separator is guided from the oil separator to or introduced into a storage tank by a return device through which the oil separated by the oil separator flows. The storage tank is preferably arranged below the oil separator in the vehicle height direction at the installation location of the internal combustion engine. Preferably, the storage tank is constructed as an oil pan, and the oil introduced into the oil pan is collected in the oil pan.

[0028] In order to particularly advantageously separate oil from leaked gas, according to the invention, the reflux device has at least one first reflux channel through which a first portion of oil separated from the leaked gas by a first oil separator flows, through which the first portion of the separated oil is guided from the first oil separator to a storage tank; and the reflux device has at least one second reflux channel, at least partially spaced apart from or separated from the first reflux channel, through which a second portion of oil separated from the leaked gas by a second oil separator flows, through which the second portion of the separated oil is guided from the second oil separator to a storage tank.

[0029] Further features of the invention are derived from the accompanying drawings and description. The features and combinations thereof mentioned in the specification, as well as the features and combinations thereof mentioned below in the description of the drawings and / or shown separately in the drawings, may be used not only in the given combinations, but also in other combinations or individually. Attached Figure Description

[0030] The invention will now be described in more detail by way of preferred embodiments and with reference to the accompanying drawings. In the drawings:

[0031] Figure 1 A schematic partial sectional view of the internal combustion engine according to the invention is shown in perspective view; and

[0032] Figure 2 A schematic partial sectional view of the internal combustion engine according to the invention is shown in a side perspective view; and

[0033] Figure 3 The previous perspective view shows a schematic partial sectional view of the internal combustion engine according to the invention; and

[0034] Figure 4 The previous perspective view shows a schematic partial sectional view of the internal combustion engine according to the present invention. Detailed Implementation

[0035] In each figure, elements that are the same or have the same function have the same reference numerals.

[0036] Figure 1 A schematic partial cross-sectional view of the internal combustion engine 1 for the motor vehicle 2 is shown in perspective view, and Figure 2 A schematic partial sectional view of the internal combustion engine 1 is shown in a side perspective view, and Figure 3 The previous perspective view shows a schematic partial cross-sectional view of the internal combustion engine 1. The motor vehicle 2 is preferably configured as an automobile, particularly as a passenger car, commercial vehicle, or truck. The internal combustion engine 1 includes an output shaft, particularly configured as a crankshaft, through 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, specifically called a cylinder crankcase, which at least partially defines at least one cylinder 4 and crankcase 5 of the internal combustion engine 1. In this embodiment, the internal combustion engine 1 includes six cylinders 4. Each of the respective cylinders 4 has a cylinder wall 6, which partially defines a combustion chamber 7. A piston is arranged in each of the respective cylinders 4, and the piston is translatably movable relative to the cylinder wall 6. The internal combustion engine 1 has an intake manifold through which air can flow and an exhaust manifold through which exhaust gases of the internal combustion engine 1 can flow. Air, specifically called fresh air, can be supplied to the combustion chamber 7 through the intake manifold, and exhaust gases can be discharged from the combustion chamber 7 through the exhaust manifold. In the activated state of the internal combustion engine, a combustion process, specifically called combustion, occurs in the respective combustion chamber 7, wherein a fuel-air mixture containing fresh air is burned, thereby producing exhaust gases of the internal combustion engine 1.

[0038] In particular, when the internal combustion engine 1 is activated, gases, especially exhaust gases, can reach the crankcase 3 or crank chamber 5 from the corresponding combustion chamber 7, particularly through the gap formed at least partially by the corresponding piston and the corresponding cylinder wall 6. The gases that reach the crankcase 3 or crank chamber 5 from the corresponding combustion chamber 7 and are located in the crank chamber 5 can be specifically referred to as blow-by gases. The internal combustion engine 1 has at least two oil separators 8 and 9, specifically constructed separately from each other, by means of which oil can be separated from the blow-by gases discharged from the crankcase 3 or crank chamber 5 and supplied to the oil separators 8 and 9. The oil separators 8 and 9 in… Figure 1 and Figure 3 The diagram is schematically simplified. The internal combustion engine 1 includes a return flow device 10 through which oil separated by oil separators 8 and 9 flows, guiding oil separated from leaking gases by oil separators 8 and 9 from the oil separators 8 and 9 to or into a storage tank 11. The storage tank 11 may be specifically constructed as an oil sump and provided for collecting oil. The storage tank 11 is preferably arranged below the oil separators 8 and 9 in the crankcase 3 or crankcase 5 along the vehicle height direction 12 in the mounting position of the internal combustion engine. The internal combustion engine 1, in its fully manufactured state, occupies the mounting position in the fully manufactured motor vehicle 2. The storage tank 11... Figure 4 The diagram shows a schematic partial cross-sectional view of the internal combustion engine 1, with the previous perspective view showing the engine 1. In the provided flow direction 12a, the oil from the cross-flow return device 10 flows from the corresponding oil separators 8 and 9 to the storage tank 11.

[0039] In order to particularly advantageously separate oil from the leaking gas, the reflux device 10 has at least one first reflux channel 14 through which a first portion 13 of oil separated from the leaking gas by means of a first oil separator 8 flows, through which the separated first portion 13 of oil can be guided from the first oil separator 8 into the storage tank 11. The reflux device also has at least one second reflux channel 16, which is at least partially spaced from or separated from the first reflux channel 14, through which a second portion 15 of oil separated from the leaking gas by means of a second oil separator 9 flows, through which the separated second portion 15 of oil can be guided from the second oil separator 9 into the storage tank 11.

[0040] This allows for a significant increase in the corresponding geodetic height difference or spacing 17, 18 along the vehicle height direction 12 between the respective oil separators 8, 9 and the storage tank 11. Specifically, this can be understood as the corresponding spacing 17, 18 extending along the vehicle height direction 12, for example, between the corresponding first points 8a, 9a of the respective oil separators 8, 9 and the second point 11a of the storage tank 11. The corresponding first points 8a, 9a are arranged, for example, in the corresponding outlet openings of the respective oil separators 8, 9, and the second point 11a is arranged in the storage tank 11. The respective oil separators 8, 9 are fluidly connected to the return flow device 10 through the corresponding outlet openings. Here, the corresponding first points 8a, 9a are preferably the lowest points of the corresponding outlet openings along the vehicle height direction 12. Because the corresponding spacing 17, 18 can be significantly increased, the corresponding pressure loss potential of the respective oil separators 8, 9 can be significantly increased. Therefore, on the one hand, the filtration efficiency of the corresponding oil separators 8 and 9 can be significantly increased, and on the other hand, oil in the storage tank 11 can be prevented from flowing upward along the vehicle height direction 12 and thus against the flow direction 12a to the corresponding oil separators 8 and 9 through the return device 10, especially the corresponding return channels 14 and 16. This significantly increases the filtration efficiency of the corresponding oil separators 8 and 9 and prevents the returned oil from being introduced into the intake manifold, thereby keeping the pollutant emissions from the internal combustion engine 1 at a particularly low level.

[0041] Preferably, in the installation position of the internal combustion engine 1 in the motor vehicle 2, the oil separators 8 and 9 are spaced equidistant from the storage tank 11 in the vehicle height direction 12. In other words, the first distance 17 between the first oil separator 8 and the storage tank 11 and the second distance 18 between the second oil separator 9 and the storage tank 11 are of the same size. Therefore, the two geodetic height differences or the two distances 17 and 18 can be significantly increased, thereby giving the two oil separators 8 and 9 a particularly high pressure loss potential.

[0042] In another embodiment, the return passages 14 and 16 each have at least one length region 20 and 21 that is permeable to oil and extends within the housing wall 19 of the crankcase 3, said length regions being at least partially, and particularly completely, circumferentially bounded by the housing wall 19, in particular directly, in their respective circumferential directions 22 and 23. The first return passage 14 or the length region 20 and 21 of the first return passage 14 is arranged in the crankcase 3 on the inlet side. The second return passage 16 or the length region 20 and 21 of the second return passage 16 is arranged in the crankcase 3 on the inlet side. Arrangement on the inlet or outlet side can be understood in particular as: a central plane extending with respect to the cylinder 4 along the vehicle height direction 12 and along the longitudinal extension direction of the output shaft, a first side of which may be called the inlet side, through which air flowing through the intake manifold is guided to the combustion chamber 7, and a second side of the central plane opposite to the first side may be called the outlet side, through which exhaust gas flowing through the exhaust manifold is discharged from the combustion chamber 7. Figure 2 The partial sectional view shown is a partial sectional view of the entrance side.

[0043] Preferably, the first oil separation device 8 is configured as a partial load oil separator, and the second oil separation device 9 is configured as a full load oil separator. Thus, the first return channel 14 is called the partial load separation channel, and the second return channel 16 is called the full load separation channel.

[0044] The internal combustion engine 1 includes a cylinder head 25, which is arranged above the crankcase 3 in the mounting position of the internal combustion engine 1 in the motor vehicle 2. Preferably, oil separators 8 and 9 are arranged in a cylinder head cover 24, which is arranged above the cylinder head 25 of the internal combustion engine 1 in the vehicle height direction 12 in the mounting position of the internal combustion engine 1 in the motor vehicle 2. The cylinder head cover 24 may be specifically referred to as a valve cover, and at least partially, and particularly directly, limits the cylinder head 25 upward in the vehicle height direction 12. In another embodiment, the return passages 14 and 16 each have at least one second length region 26 and 27 arranged upstream of the respective length regions 20 and 21, through which oil can flow, along the oil flow direction 12a of the return passages 14 and 16. The second length regions extend inside the cylinder head 25, and the respective second length regions 26 and 27 at least partially, and particularly completely, circumferentially limit the cylinder head 25, particularly directly, in their respective circumferential directions 28 and 29. Thus, oil can be guided from the corresponding oil separators 8 and 9 through the cylinder head 25 and crankcase 3 into the storage tank 11, wherein, in particular, since the oil separators 8 and 9 are arranged in the cylinder head cover 24, the spacing 17 and 18 can be increased.

[0045] In another embodiment, the internal combustion engine 1 includes corresponding manifolds 30, 31, at which return channels 14, 16 converge into at least one receiving area 32 directly bounded by a storage tank 11, where oil can be received. Thus, oil flowing through the return channels 14, 16 can be discharged or exported from the respective return channels 14, 16 through the corresponding manifolds 30, 31, and can be introduced into the storage tank 11 or the receiving area 32. The manifolds 30, 31 are located in... Figure 4 The following is a simplified illustration and schematic representation. Preferably, the return channels 14 and 16 each have at least one third length region 33 that can be traversed by oil and is arranged downstream of the respective length regions 20 and 21 in the flow direction 12a of the oil traversing the return channels 14 and 16. The third length region extends inside the tank wall 34 of the storage tank 11, wherein the third length region 33 is at least partially, and in particular completely, circumferentially bounded by the tank wall 34, particularly directly, in its circumferential direction.

[0046] In another embodiment, in the mounting position of the internal combustion engine 1 in the motor vehicle 2, at least one manifold 30, 31 is arranged in the vehicle height direction 12 below the oil level 35, specifically referred to as the oil level, of the oil in the reservoir 11. Thus, the reservoir 11 can have a siphon function, specifically referred to as an oil siphon, thereby eliminating the need for a separate oil siphon constructed separately from the reservoir 11, wherein the oil collected in the reservoir 11 can flow out from the reservoir 11, for example, laterally or laterally downward in the vehicle height direction, when exceeding a defined fill height of the reservoir 11. In other words, the oil siphon can be moved into the reservoir 11. Again, in other words, the third length region 33 can extend the corresponding return channels 14, 16 in the vehicle height direction 12 all the way below the oil level 35. Alternatively, at least one of the manifolds 30, 31 can be arranged in the vehicle height direction 12 above the oil level 35 in the mounting position of the internal combustion engine 1.

[0047] Preferably, the corresponding return channels 14, 16, and in particular at least one of the corresponding length regions 20, 21, 26, 27, 33, are manufactured by drilling and / or by casting. Thus, the internal combustion engine 1, and in particular the corresponding return channels 14, 16, can be manufactured particularly advantageously and cost-effectively. In at least one of the corresponding return channels 14, 16, and particularly in the corresponding length regions 20, 21, at least one valve device 36, particularly called a check valve, can be arranged, by means of which the corresponding mass flow of oil flowing through the corresponding return channels 14, 16 can be set. Thus, for example, it can be particularly advantageous to prevent, for example, the backflow of oil from the storage tank 11 through the corresponding return channels 14, 16 to the corresponding oil separators 8, 9, extending in the opposite direction of flow 12a.

[0048] List of reference numerals

[0049] 1 Internal Combustion Engine

[0050] 2 motor vehicles

[0051] 3 crankcase

[0052] 4 cylinders

[0053] 5 crankshaft chambers

[0054] 6-cylinder wall

[0055] 7 Combustion Chamber

[0056] 8 First oil separation unit

[0057] 8a First point

[0058] 9. Second oil separation unit

[0059] 9a First point

[0060] 10 reflux devices

[0061] 11 storage tanks

[0062] 11a Second point

[0063] 12 Vehicle height direction

[0064] 12a Flow direction

[0065] 13 Part 1

[0066] 14 First Return Channel

[0067] 15 Part Two

[0068] 16 Second Return Channel

[0069] 17 First Spacing

[0070] 18 Second Spacing

[0071] 19 Shell Wall

[0072] 20 length region

[0073] 21 length region

[0074] 22-week direction

[0075] 23 circumferential direction

[0076] 24 Cylinder Head Cover

[0077] 25 cylinder head

[0078] 26 Second Length Region

[0079] 27 Second Length Region

[0080] 28 circumferential direction

[0081] 29th week direction

[0082] 30 First confluence section

[0083] 31 Second confluence section

[0084] 32 receiving area

[0085] 33 Third Length Region

[0086] 34 Tank Wall

[0087] 35 oil level

[0088] 36 valve device

Claims

1. An internal combustion engine (1) for a motor vehicle (2), said internal combustion engine comprising: Crankcase (3); At least two oil separators are provided, by means of which oil can be separated from the leaking gas discharged from the crankcase (3) and supplied to the oil separators; and a return flow device (10) through which the oil separated by the oil separators can be guided from the oil separators to the storage tank (11). The reflux device (10) is characterized in that it has at least one first reflux channel (14) and at least one second reflux channel (16). The first reflux channel is capable of carrying through a first portion (13) of the oil separated from the leaking gas by means of a first oil separator (8) in the oil separator, through which the first portion (13) of the separated oil can be guided from the first oil separator (8) to the storage tank (11). The second reflux channel is at least partially spaced from the first reflux channel (14) and is capable of carrying through a second portion (15) of the oil separated from the leaking gas by means of a second oil separator (9), through which the second portion (15) of the separated oil can be guided from the second oil separator (9) to the storage tank (11). The first reflux channel and the second reflux channel each have at least one first reflux channel that is capable of carrying through the oil and extends inside the housing wall (19) of the crankcase (3). The first length region (20, 21), which is at least partially bounded by the shell wall (19) in its circumferential direction (22, 23), has corresponding confluence points (30, 31) at which the first return channel and the second return channel merge into a receiving area (32) bounded by the storage tank (11), where the oil can be received. At least one of the confluence points (30, 31) is arranged along the vehicle height direction (12) below the oil surface (35) of the oil in the storage tank (11). The first return channel and the second return channel each have at least one third length region (33) that can be traversed by oil and is arranged in the flow direction (12a) of the oil traversing the return channel downstream of the corresponding first length region (20, 21). The third length region extends inside the storage tank wall (34) of the storage tank (11) and is at least partially bounded by the storage tank wall (34) in its circumferential direction.

2. The internal combustion engine (1) according to claim 1, characterized in that, The first oil separator and the second oil separator are spaced at the same distance from the storage tank (11) in the vehicle height direction (12).

3. The internal combustion engine (1) according to claim 1, characterized in that, The oil separator is arranged in the cylinder head cover (24), which is arranged above the cylinder head (25) of the internal combustion engine (1) along the vehicle height direction (12).

4. The internal combustion engine (1) according to claim 3, characterized in that, The first return channel and the second return channel each have at least one second length region (26, 27) that can be traversed by oil and is arranged upstream of the respective length region (20, 21) along the oil flow direction (12a) of the return channel. The second length region extends inside the cylinder head (25), wherein the second length region (26, 27) is at least partially bounded by the cylinder head (25) in its circumferential direction (28, 29).

5. The internal combustion engine (1) according to any one of claims 1 to 4, characterized in that, The corresponding return channels are made by drilling and / or by casting.

6. A motor vehicle (2) having an internal combustion engine (1) according to any one of claims 1 to 5.

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