Internal combustion engine for a motor vehicle, and motor vehicle

Abstract

The invention relates to an internal combustion engine (1), comprising a crankcase (2), an inlet section (4) through which air can flow, and a crankcase ventilation device (18) which has a suction jet pump (19), into which at least one part of the air from the inlet section (4) can be fed in order to ventilate the crankcase (2) such that, in order to ventilate the crankcase (2), a gas can be suctioned, as a suction medium, from the crankcase (2) by means of the suction jet pump (19) using the air fed into the suction jet pump as a propellant for the suction jet pump (19). A supply line (30) is provided via which the suction jet pump (19) can be supplied with the propellant, and a suction line (46) is provided via which the suction medium can be suctioned from the crankcase (2) by means of the suction jet pump (19) and can be delivered thereto. In addition to the supply line (30) and in addition to the suction line (46), a branching line (48) is provided, by means of which at least one part of the air from the inlet section (4) can be introduced into the suction line (46).

Description

[0001] Internal combustion engine for a motor vehicle and motor vehicle

[0002] The invention relates to an internal combustion engine for a motor vehicle, in particular for a motor vehicle, according to the preamble of patent claim 1. Furthermore, the invention relates to a motor vehicle with such an internal combustion engine.

[0003] EP 3 020 934 B1 discloses a known vehicle having an internal combustion engine with a crankcase and a supercharging device. Also provided is a crankcase ventilation device having at least one inertia-based oil separation device with at least one inertia-based oil separator, an oil return line returning separated oil to the crankcase, and a suction jet pump driven by compressed air from the supercharging device and generating a vacuum to drive blow-by gas. Furthermore, EP 2 815 089 B1 discloses a vehicle having an internal combustion engine with a crankcase. Also provided is a crankcase ventilation device having at least one oil separation device and an oil return line returning separated oil to the crankcase. Also provided is a conveying device for driving a fluid other than blow-by gas.The conveyor is also used to drive the blow-by gas in the crankcase ventilation system.

[0004] The object of the present invention is to provide an internal combustion engine for a motor vehicle and a motor vehicle with such an internal combustion engine, so that a particularly advantageous crankcase ventilation can be realized.

[0005] This object is achieved by an internal combustion engine having the features of patent claim 1 and by a motor vehicle having the features of patent claim 10. Advantageous embodiments of the invention are specified in the dependent claims. A first aspect of the invention relates to an internal combustion engine, also referred to as an internal combustion engine, motor, or combustion engine, and preferably designed as a reciprocating piston engine, thus as a reciprocating piston machine, for a motor vehicle, also simply referred to as a vehicle. This means that the motor vehicle, preferably designed as a motor vehicle, in particular as a passenger car, has the internal combustion engine in its fully manufactured state and can be driven by the internal combustion engine. The internal combustion engine has a crankcase.For example, the internal combustion engine has an output shaft designed as a crankshaft, which is mounted on the crankcase so as to be rotatable about a shaft rotation axis relative to the crankcase. The internal combustion engine can provide drive torque to power the motor vehicle via the crankshaft. The internal combustion engine also has an intake tract through which air flows, also referred to as the intake tract. The air flowing through the intake tract is also referred to as combustion air or fresh air.

[0006] The internal combustion engine also has a crankcase ventilation system, which is also simply referred to as crankcase ventilation. The crankcase ventilation system has a suction jet pump, to which at least a portion of the air, also referred to as the first portion, can be supplied from the intake tract for venting the crankcase. Such that, for venting the crankcase, a gas can be sucked in from the crankcase as a suction medium by means of the suction jet pump, using the air supplied to the suction jet pump as the driving medium for the suction jet pump, and can thus be pumped out of the crankcase. In other words, during operation of the internal combustion engine, the aforementioned portion of the air from the intake tract (intake tract) is supplied to the suction jet pump.The portion of the air supplied to the ejector pump is used as the driving medium for the ejector pump. The ejector pump uses the driving medium to suck in the gas from the crankcase and expel it, thereby venting the crankcase. The gas is thus the suction medium, which is sucked from the crankcase by the ejector pump and with the help of the driving medium and expelled from the crankcase. For example, venting the crankcase can prevent excessive pressure in the crankcase.The gas includes, for example, a so-called blow-by gas, which originates, for example, from at least one combustion chamber of the internal combustion engine and flows between a piston and a corresponding cylinder wall of the internal combustion engine, thereby flowing into the crankcase, in particular into a crankcase of the crankcase. The crankcase, and thus the crankcase, can be effectively and efficiently vented by means of the suction jet pump and the propellant medium.

[0007] The crankcase ventilation system has a supply line via which the suction jet pump can be supplied with the driving medium. For example, the said portion of the air can be branched off from the inlet tract as the driving medium by means of the supply line and introduced into the supply line, whereupon the portion of the air branched off from the inlet tract, i.e. the air branched off from the inlet tract, can flow through the supply line and be guided to the suction jet pump by means of the supply line, whereby the suction jet pump is supplied with the air branched off from the inlet tract as the driving medium. Thus, for example, the suction jet pump can be or is fluidly connected to the inlet tract via the supply line.The crankcase ventilation device also has a suction line through which the suction medium, and therefore the gas, can be sucked in from the crankcase by means of the suction jet pump and conveyed to the suction jet pump. Thus, for example, the suction jet pump is or can be fluidly connected to the crankcase, in particular to the crank chamber, via the suction line. In particular, it is conceivable for the crankcase ventilation device to have a mixture line through which a mixture comprising the suction medium and the driving medium can flow. This means that the suction medium and the driving medium can flow through at least the respective part of the suction jet pump, mix and thereby form the said mixture, which can flow through the mixture line and, in particular, be discharged from the suction jet pump by means of the mixture line.For example, the mixture can be introduced into the intake tract via or by means of the mixture line, particularly at an inlet point. For this purpose, the mixture line is, or can be, fluidically connected to the intake tract at the inlet point. For example, the mixture line opens into the intake tract at the inlet point.

[0008] For example, the crankcase ventilation device has an oil separator through which the suction medium can be fed to the suction jet pump. Thus, for example, the oil separator is arranged in the suction line or upstream of the suction line, in particular viewed in the flow direction of the suction medium flowing through the suction line. Thus, for example, the suction jet pump can suck in the suction medium via the oil separator, so that the suction medium flows through the oil separator on its way from the crankcase to the suction jet pump. By means of the oil separator, any oil contained in the gas can be separated from the gas. Very preferably, the oil separator is designed as a, in particular purely passive, oil separator, by means of which a, in particular purely passive, oil separation can be carried out in order to separate any oil contained in the suction medium from the suction medium, and thus from the gas.In particular, the suction jet pump and preferably the mixture line and very preferably also the oil separator are components of a full-load crankcase ventilation system, by means of which the crankcase is to be vented or is vented when the internal combustion engine is at full load. The feature that the suction jet pump and preferably the mixture line and very preferably also the oil separator are components of the said full-load crankcase ventilation system, which is also referred to as full-load ventilation, is to be understood in particular that the mixture line and the suction jet pump and preferably also the oil separator are arranged in a so-called full-load path, via which the crankcase is to be vented or is vented when the internal combustion engine is at full load, i.e. when the internal combustion engine is operating at full load.The suction jet pump can achieve a particularly high separation efficiency, especially when the oil separator is a purely passive oil separator. In particular, pressure losses caused by the passive oil separator, for example, can be compensated.

[0009] In order to vent the crankcase particularly advantageously, and thus to be able to implement particularly advantageous crankcase ventilation, a branch line is provided according to the invention in addition to the supply line and in addition to the suction line, by means of which branch line at least a part of the air, also referred to as the second part, can be introduced from the inlet tract into the suction line, in particular bypassing the suction jet pump. This means that, for example, by means of the supply line, a second part of the air, provided in particular in addition to the aforementioned first part of the air, can be branched off from the inlet tract and introduced into the branch line, wherein the second part of the air branched off from the inlet tract can flow through the branch line and can be conveyed to the suction line by means of the branch line and introduced into the suction line.This makes it possible to avoid unfavorable values ​​of a pressure prevailing in the crankcase, particularly in the crank chamber, also referred to as crankcase pressure, thus achieving particularly advantageous crankcase ventilation. In particular, the use of the additional branch line makes it possible to limit the crankcase pressure and thus avoid excessive crankcase pressure. In particular, the invention creates an advantageous prerequisite for, for example, advantageously adjusting, in particular controlling or regulating, the crankcase pressure as needed, so that the invention enables, for example, regulation of the crankcase pressure.

[0010] The feature that the third part of the air from the inlet tract can be introduced into the suction line bypassing the suction jet pump means that the air does not flow through the suction jet pump on its way from the inlet tract to the suction line and through the branch line, but only flows through the suction jet pump after it has flowed out of the branch line and into the suction line.

[0011] The invention is based in particular on the following findings and considerations: the suction jet pump, also referred to as SSP, can assist the oil separator in separating the oil from the gas by additionally generating a negative pressure, which can be used to achieve an advantageously high degree of separation. For this purpose, the suction jet pump uses the motive medium, i.e. a motive jet formed by the flowing motive medium, to suck in the suction medium by means of the motive medium and in doing so convey it towards itself and, for example, through the oil separator, since, for example, the suction medium flows through the oil separator on its way from the crankcase to the suction jet pump. A function, in particular a performance of the suction jet pump is therefore dependent on a pressure of the motive medium.If, for example, a compressor is arranged in the intake tract by means of which the fresh air can be or is compressed, the driving medium is the fresh air from the intake tract compressed by the compressor. Since the compression of the air by means of the compressor is also referred to as supercharging, the pressure of the driving medium is also referred to as boost pressure. Since the pressure of the fresh air, and therefore the pressure of the driving medium, is usually greater in an upper load range than in a lower load range of the internal combustion engine, unless countermeasures are taken, the power or performance of the suction jet pump with regard to sucking in the gas from the crankcase is greater in the upper load range than in the lower load range.It has been found that this can lead to an undesirable drop in crankcase pressure in the upper load range, which can now be avoided by the invention. For this purpose, the branch line is used as an additional line which introduces, in particular blows, the second part of the air into the suction line and thus, for example, in the flow direction of the suction medium flowing through the suction line (of the internal suction jet pump). As a result, the performance of the suction jet pump is deliberately impaired, particularly in the upper load range and especially at full load of the internal combustion engine, which on the one hand can prevent an excessive drop in crankcase pressure. On the other hand, sufficient performance of the suction jet pump can still be guaranteed, so that advantageous crankcase ventilation can be ensured even in the upper load range.Furthermore, the invention makes it possible to design the suction jet pump particularly advantageously for the lower load range, so that advantageous crankcase ventilation can be realized both in the upper load range and in the lower load range.

[0012] In particular, if the second part of the air can be introduced or is introduced into the suction line downstream of the oil separator by means of the branch line, oil can be separated from the gas particularly advantageously by means of the oil separator, since in comparison to conventional solutions the oil separator can be operated for a longer period in a range which is advantageous for oil separation.

[0013] In order to be able to vent the crankcase particularly advantageously, one embodiment of the invention provides that the supply line is fluidically connected to the inlet tract at a first connection point and to the suction jet pump at a second connection point, wherein the branch line is fluidically connected to the inlet tract at a third connection point, which is different from the first connection point and also from the second connection point, and to the suction line at a fourth connection point, which is different from the second connection point, the first connection point, and the third connection point. Thus, by means of the supply line at the first connection point, the first part of the air can be branched off from the inlet tract and introduced into the supply line, wherein the air flowing through the supply line can be introduced into the suction jet pump at the second connection point.By means of the branch line, the second part of the air can be branched off from the intake tract at the third connection point, wherein the air flowing through the branch line can be guided by means of the branch line to the fourth connection point and introduced into the branch line at the fourth connection point. To achieve particularly advantageous crankcase ventilation, it has proven particularly advantageous if the third connection point is arranged upstream of the first connection point in the flow direction of the air flowing through the intake tract. As a result, for example, the air at the third connection point can have a lower pressure than at the first connection point, so that an excessive drop in the crankcase pressure can advantageously be avoided.

[0014] A further embodiment is characterized in that the first connection point is arranged downstream of the compressor arranged in the intake tract for compressing the air flowing through the intake tract, in the flow direction of the air flowing through the intake tract. This allows advantageous crankcase ventilation to be achieved, particularly in the lower load range, since advantageous performance, in particular a particularly high performance of the ejector pump, can be ensured in the lower load range. In the upper load range, the excessively high performance of the ejector pump with regard to the suction of the suction medium can be avoided, so that advantageous crankcase ventilation can be ensured both in the low-load range and the high-load range.

[0015] In order to avoid an excessive and undesirable drop in the crankcase pressure, particularly in the upper load range, and thus to be able to provide particularly advantageous crankcase ventilation, it is provided in a further embodiment of the invention that the third connection point is arranged upstream of the compressor in the flow direction of the air flowing through the inlet tract.

[0016] In order to be able to avoid excessively low values ​​of the crankcase pressure, in particular in the upper load range, so that the crankcase can be vented particularly advantageously, it is provided in a further embodiment of the invention that the fourth connection point is arranged upstream of the second connection point in the flow direction of the gas flowing through the intake line.

[0017] It has proven particularly advantageous if the fourth connection point is arranged downstream of the crankcase in the flow direction of the gas flowing through the suction line, thereby avoiding excessive performance of the suction jet pump, particularly in the upper load range. To vent the crankcase particularly advantageously, it is advantageously provided that the fourth connection point is arranged downstream of the oil separator in the flow direction of the gas flowing through the suction line, whereby any oil contained in the gas can be particularly advantageously separated from the gas by means of the oil separator.

[0018] A further embodiment is characterized in that at least a length of the suction line is formed by a suction nozzle of a housing of the ejector pump, wherein the branch line opens into the suction nozzle. In this case, it is provided, for example, that the fourth connection point is arranged on or in the suction nozzle. This allows the second part of the air to be introduced into the suction line in a particularly advantageous manner in order to avoid excessive performance of the ejector pump, particularly in the peak load range. For example, the housing of the ejector pump, also referred to as a jet pump, defines a mixing chamber into which a driving nozzle of the ejector pump, arranged in the housing, opens. The driving medium flows out of the driving nozzle and into the mixing chamber, in which a static pressure drop occurs according to Bernoulli's law.The suction medium can be introduced into the mixing chamber via the suction lines, in particular via the suction nozzle. Due to the aforementioned pressure drop, the suction medium is sucked into the mixing chamber and thus conveyed by the propellant medium. The previously mentioned length of the suction line formed by the suction nozzle is also referred to as the first length of the suction line. For example, a second length of the suction line is formed by a line element formed separately from the suction nozzle and separately from the housing of the ejector pump, which is fluidically and preferably also mechanically connected to the suction nozzle.In particular, it is conceivable that at least part of the mixing chamber is delimited by a housing element of the housing, wherein it is conceivable that at least part of the intake port is formed integrally with the housing element, so that preferably at least part of the intake port and the housing element are formed from a single piece and thus designed as a monoblock. It is possible to introduce the second part of the air flowing through the branch line from the inlet tract into the intake port and thus into the intake port shortly before the mixing chamber, so that unfavorable crankcase pressure values, particularly in the high-load range, can be advantageously avoided.In order to particularly advantageously avoid unfavorable values ​​of the crankcase pressure and, for example, to be able to adjust the crankcase pressure particularly advantageously and as needed, i.e. to be able to vary it, a further embodiment of the invention provides that a valve device is arranged in the branch line, by means of which a quantity of the air originating from the intake tract flowing through the branch line, i.e. of the second part of the air, can be adjusted. In particular, it is possible to use the valve device to adjust, in particular to regulate, the quantity of air from the intake tract flowing through the branch line to at least two values ​​that are different from one another and from zero and greater than zero. In this way, for example, the crankcase pressure can be adjusted or regulated particularly advantageously, whereby particularly advantageous crankcase ventilation can be achieved.For example, the valve device can be operated electrically, electronically, or mechanically, whereby the air flowing through the branch line can be adjusted particularly advantageously and as needed. In particular, the valve device can be a control device or a component of a control device, whereby the amount flowing through the branch line can be advantageously adjusted and thus regulated by means of the control device, whereby, for example, the crankcase pressure can be particularly advantageously adjusted and, in particular, regulated. For example, the valve device can be electrically controlled and, for example, thus regulated, in particular by means of an electronic computing device.For this purpose, the electronic computing device can, for example, provide a control signal, in particular an electrical one, which can be received by the valve device, whereby the valve device can be controlled and thus, for example, regulated. This allows, for example, the amount of fluid flowing through the branch line to be adjusted, in particular regulated.

[0019] A second aspect of the invention relates to a motor vehicle, also referred to simply as a vehicle, and preferably designed as a motor vehicle, in particular as a passenger car, which has an internal combustion engine according to the first aspect of the invention. Advantages and advantageous embodiments of the first aspect of the invention are to be regarded as advantages and advantageous embodiments of the second aspect of the invention, and vice versa.

[0020] Further details of the invention will become apparent from the following description of a preferred embodiment with the accompanying drawing. The sole FIG. 1 shows a schematic representation of an internal combustion engine for a motor vehicle.

[0021] Fig. 1 shows a schematic representation of an internal combustion engine 1, also referred to as an internal combustion engine, motor or combustion engine, and designed as a reciprocating piston engine, thus as a reciprocating piston machine, for a motor vehicle, also simply referred to as a vehicle. The internal combustion engine 1 has a crankcase 2, through which, for example, several cylinders 3 of the internal combustion engine 1 are formed. Thus, the crankcase 2 is designed, for example, as a cylinder crankcase. A respective combustion chamber of the internal combustion engine 1 is partially formed by each cylinder 3. The internal combustion engine 1 also has an intake tract 4, also referred to as an intake tract, through which air, which is also referred to as fresh air or combustion air, can flow. By means of the intake tract 4, the air flowing through the intake tract 4 can be guided to and into the combustion chambers. In Fig.In Figure 1, arrows 5 illustrate a first flow direction, also referred to as the air flow direction. Air can or does flow through the intake tract 4 in the air flow direction, thereby directing the air to and into the combustion chambers. In other words, the air flows through the intake tract 4 in the air flow direction on its way through the intake tract 4 toward and into the combustion chambers.

[0022] An air filter 6 is arranged in the intake tract 4, by means of which the air flowing through the intake tract 4 is filtered. The internal combustion engine 1 also has an exhaust tract 7, through which exhaust gas from the combustion chambers can flow. In Fig. 1, an arrow 8 illustrates a second flow direction in which the exhaust gas from the combustion chambers flows or can flow through the exhaust tract 7, whereby the exhaust gas can be discharged from the combustion chambers. In the embodiment shown in Fig. 1, the internal combustion engine 1 has an exhaust gas turbocharger 9, which has a compressor 10 arranged in the intake tract 4 and a turbine 11 arranged in the exhaust tract 7. The turbine 11 can be driven by the exhaust gas flowing through the exhaust tract 7.The turbine 11 can drive the compressor 10 via a shaft 12 of the exhaust gas turbocharger 9. By driving the compressor 10, the air flowing through the intake tract 4 can be compressed, and thus supercharged, by means of the compressor 10. The combustion chambers of the internal combustion engine 1 can thus be supplied with the air compressed by the compressor 10, which is also referred to as supercharging or supercharging of the internal combustion engine 1. For example, the internal combustion engine 1 is operated in a supercharged mode at least in a first region of its characteristic map, so that in the first region of the characteristic map, also referred to as the first region of the characteristic map, the combustion chambers are supplied with air from the intake tract 4 compressed by the compressor 10. For example, in at least a second region of the characteristic map, the internal combustion engine 1 is operated in a non-supercharged mode.The second area of ​​the map is also referred to as the second area of ​​the map or the non-charged area of ​​the map. In the second area of ​​the map, for example, the combustion chambers are not supplied with air compressed by the compressor 10, wherein the combustion chambers are supplied with air from the intake tract 4, but the air with which the combustion chambers are supplied is not charged by the compressor 10. For example, the first area of ​​the map is or includes a full load, i.e., full-load operation of the internal combustion engine 1. Furthermore, it is conceivable that the second area of ​​the map is or includes a partial load, i.e., partial-load operation of the internal combustion engine 1.

[0023] The internal combustion engine 1 is operable in its fired mode using a preferably liquid fuel. During fired mode, a fuel-air mixture is combusted in the respective combustion chamber within a respective working cycle of the internal combustion engine 1, resulting in the exhaust gas. The fuel-air mixture comprises the preferably liquid or gaseous fuel and the air from the intake tract 4. The internal combustion engine 1 has a fuel tank 13, shown particularly schematically in Fig. 1 and simply referred to as a tank, in which the fuel can be or is held at least temporarily. The internal combustion engine 1 has a tank venting device 14, which is provided or designed to vent the fuel tank 13 and is also referred to as the first venting device.The tank ventilation device 14 has a first suction jet pump 15, which is also referred to as a first jet pump. At least a first portion of the air from the intake tract can be supplied to the first suction jet pump 15 for venting the fuel tank 13, so that for venting the fuel tank 13 by means of the first suction jet pump 15, using the air supplied to the first suction jet pump 15 as the first propellant medium for the first suction jet pump 15, a first gas can be sucked in as the first suction medium from the fuel tank 13 and thus pumped out of the fuel tank 13. The tank ventilation device 14 has a first mixture line 16 through which a first mixture comprising the first suction medium and the first propellant medium can flow. In Fig.1, an arrow 17 indicates a third flow direction in which the first mixture flows through the mixture line 16 in order to thereby discharge the first mixture from the suction jet pump 15.

[0024] The internal combustion engine 1 further comprises a crankcase ventilation device 18, which is also referred to as a second ventilation device. The crankcase ventilation device 18 comprises a second suction jet pump 19, also referred to as a second jet pump, to which at least a second portion of the air from the intake tract 4 can be supplied for venting the crankcase 2. Such that, for venting the crankcase 2, a second gas can be sucked in as a second suction medium from the crankcase 2 and thus pumped out of the crankcase 2 by means of the second suction jet pump 19, using the air supplied to the second suction jet pump 19 as a second propulsion medium for the second suction jet pump 19. The crankcase ventilation device 18 has a second mixture line 20, through which a second mixture comprising the second suction medium and the second propulsion medium can flow. In Fig.1, an arrow 21 indicates a fourth flow direction in which the second mixture flows through the second mixture line 20 in order to discharge the second mixture from the suction jet pump 19, i.e., to carry it away. A fifth flow direction opposite to the fourth flow direction is illustrated by an arrow 22. The second mixture can be introduced into the inlet tract 4 at an inlet point E via or by means of the second mixture line 20. For this purpose, the mixture line 20 is fluidically connected to the inlet tract 4 at the inlet point E. The first mixture line 16 is fluidically connected to the second mixture line 20 at a connection point V which, with respect to the fourth flow direction illustrated by the arrow 21, is arranged upstream of the inlet point E and downstream of the second suction jet pump 19, in particular in the second mixture line 20.At the connection point V, the first mixture can be discharged from the first mixture line 16 and introduced into the second mixture line 20. From Fig. 1 it can be seen that the second mixture line 20 has a first length range L1 which extends, in particular continuously and thus without interruption, from the connection point V to the introduction point E. L2 designates a second length range of the mixture line 20. The second length range L2 extends from the connection point V, in particular continuously and thus without interruption, to the suction jet pump 19 and vice versa, so that with respect to the fourth flow direction illustrated by the arrow 21, the second length range L2 is arranged upstream of the first length range L1. The length ranges L1 and L2 are fluidically connected to one another, wherein, for example, the length range L2 immediately and thus directly merges into the length range L1 and vice versa.

[0025] The crankcase ventilation system 18 also includes an oil separator 23, which is preferably designed as a passive oil separator, in particular a purely passive oil separator, by means of which any oil contained in the second gas can be passively separated from the gas, in particular in pure form. In the present case, the suction jet pump 19, the mixture line 20, and also the oil separator 23 are components of a full-load crankcase ventilation system 24, by means of which the crankcase 2 is to be or is to be vented at full load, i.e., during full-load operation of the internal combustion engine 1. The suction jet pump 19, the mixture line 20 and, in this case, also the oil separator 23 are thus in a full-load path 25 of the crankcase ventilation device 18, in particular the full-load crankcase ventilation 24, wherein the second gas can be or is discharged from the crankcase 2 via the full-load path 25, in particular during full-load operation of the internal combustion engine 1.If, particularly during full-load operation of the internal combustion engine 1, the crankcase 2 is vented via the full-load path 25 by means of the suction jet pump 19, the second gas flows from the crankcase 2 in the fourth flow direction, illustrated by the arrow 21, through the full-load path 25 and thus through the oil separator 23, the suction jet pump 19, and the mixture line 20. With respect to the fourth flow direction, the oil separator 23 is arranged upstream of the suction jet pump 19, which is arranged, for example, upstream of at least part of the mixture line 20. By means of the suction jet pump 19, a particularly advantageous pressure ratio can be realized, by means of which the crankcase 2 can be vented particularly advantageously and, in particular, a particularly high separation efficiency of the oil separator 23 can be realized.In addition, for example, during partial load, i.e., during partial load operation of the internal combustion engine 1, a beneficial purge air flow can occur, which is formed by air from the intake tract 4. This purge air flow is explained in more detail below.

[0026] In the embodiment shown in Fig. 1, the internal combustion engine 1 has a check valve 26 which, with respect to the fourth flow direction illustrated by the arrow 21, is arranged downstream of the connection point V in the second mixture line 20 and automatically opens in the direction of the inlet tract 4 and closes in the direction of the connection point V. As a result, for example, the second mixture can flow through the mixture line 20 and the check valve 26 in the fourth flow direction and thus flow into the inlet tract 4 at the inlet point E.However, in the fifth flow direction illustrated by arrow 22, which is opposite to the fourth flow direction, the check valve 26 closes automatically and thus blocks the mixture line 20 for a flow coming from the inlet tract 4 and flowing in the direction of the connection point V, so that, for example, a backflow of air from the inlet tract 4 to the connection point V via the check valve 26 can be prevented. For example, the check valve 26 is arranged upstream of the inlet point E and downstream of the connection point V with respect to the fourth flow direction illustrated by arrow 21, or the check valve 26 is arranged at the inlet point E and thus downstream of the connection point V.

[0027] The inlet tract 4 has a supply point VS at which both the first part of the air flowing through the inlet tract 4 can be branched off from the inlet tract 4 and supplied as the first driving medium to the first suction jet pump 15 and the second part of the air flowing through the inlet tract 4 can be branched off from the inlet tract 4 and supplied as the second driving medium to the second suction jet pump 19.

[0028] A throttle valve 27 is arranged in the intake tract 4, by means of which throttle valve 27 the amount of air flowing through the intake tract 4 to be supplied to the combustion chambers of the internal combustion engine 1 can be adjusted. Furthermore, a charge air cooler 28 is arranged in the intake tract 4, which is located downstream of the compressor 10 and downstream of the throttle valve 27. The air compressed by the compressor 10 and thus heated can be cooled by the charge air cooler 28. In the embodiment shown in Fig. 1, the supply point VS is arranged upstream of the throttle valve 27 and downstream of the compressor 10, and in this case downstream of the charge air cooler 28, in the flow direction of the air flowing through the intake tract 4 and towards the combustion chambers. The respective propellant can thus be air originating from the intake tract 4, compressed by the compressor 10.

[0029] The internal combustion engine 1 has a first supply line 29, which is fluidically connected to the intake tract 4 at a first branching point AZ1. By means of the supply line 29, at least a portion of the air flowing through the intake tract 4 is branched off from the intake tract 4 at the first branching point AZ1 and introduced into the first supply line 29, wherein the portion of the air flowing through the intake tract 4 branched off from the intake tract 4 at the branching point AZ1 and introduced into the supply line 29 is also referred to as supply air. The internal combustion engine 1 also has a second supply line 30, which is fluidically connected to the first supply line 29 at a second branching point AZ2.In the flow direction of the supply air flowing through the supply line 29 and from the branch point AZ1 toward the suction jet pump 15, the branch point AZ2 is located downstream of the branch point AZ1 and upstream of the suction jet pump 15. By means of the supply line 30, a first portion of the supply air is left in the supply line 29, and a second portion of the supply air is branched off from the supply line 29 at the second branch point AZ2 and introduced into the supply line 30 and guided to the suction jet pump 19 by means of the supply line 30, so that the second portion of the supply air branched off from the supply line 29 at the branch point AZ2 is used as the second propulsion medium for the suction jet pump 19. Thus, the second portion of the supply air is the aforementioned second portion of the air from the inlet tract 4, used as the second propulsion medium.The first portion of the supply air left in the supply line 29, i.e., the remaining first portion, is guided to the suction jet pump 15 via the supply line 29 and used as the first propulsion medium for the suction jet pump 15. Thus, the first portion of the supply air is the aforementioned first portion of the air from the inlet tract 4 used as the first propulsion medium. It can be seen that the supply point VS is the first branch point AZ, so that both suction jet pumps 15 and 19 can be supplied with the propulsion media via the supply point VS or branch point AZ1 common to the suction jet pumps 15 and 19.

[0030] The supply line 29 is also referred to, for example, as the first drive line, since the suction jet pump 15 is supplied with the first drive medium via the supply line 29. The second supply line 30 is also referred to, for example, as the second drive line, since the suction jet pump 19 can be or is supplied with the second drive medium via the supply line 30. In Fig. 1, a first suction line is designated 31. The first suction line 31 is, for example, a component of the tank ventilation device 14. The first suction medium from the fuel tank 13 can be supplied to the suction jet pump 15 via the first suction line 31, in particular via a tank ventilation valve 32 of the tank ventilation device 14. For example, the tank ventilation valve 32 is arranged in the suction line 31.For example, a pressure sensor 33 of the tank ventilation device 14 can be arranged in the suction line 31, in particular such that, in the flow direction of the first suction medium flowing through the suction line 31 and in particular from the fuel tank 13 to the suction jet pump 15, the pressure sensor 33 is arranged upstream of the suction jet pump 15 and downstream of the fuel tank 13. A pressure prevailing in the suction line 31 can be detected by means of the pressure sensor 33. For example, a pressure sensor 34, shown particularly schematically in Fig. 1, is arranged in the supply line 30, in particular such that, in the flow direction of the second propellant medium flowing through the supply line 30 and thereby towards the suction jet pump 19, the pressure sensor 34 is arranged upstream of the suction jet pump 19 and in particular downstream of the branch point AZ2.The pressure sensor 34 can be used to detect the pressure prevailing in the supply line 30. The pressure sensor 34 is preferably arranged particularly close to the suction jet pump 19.

[0031] In the embodiment shown in Fig. 1, the crankcase ventilation device 18 has a partial-load crankcase ventilation 35, provided in particular in addition to the full-load crankcase ventilation 24, by means of which the crankcase 2 is or can be vented during partial load, i.e., during partial load operation of the internal combustion engine 1. The partial-load crankcase ventilation 35 has a partial-load path 36, via which the crankcase 2 is vented during partial load operation of the internal combustion engine 1.

[0032] The crankcase ventilation device 18 has a second suction line 46, via which the second gas from the crankcase 2 can be supplied to the suction jet pump 19. In other words, the suction jet pump 19 sucks in the second gas from the crankcase 2 via the second suction line 46, in particular when the crankcase 2 is vented by means of the crankcase ventilation device 18, in particular by means of the full-load crankcase ventilation 24, in particular during full-load operation of the internal combustion engine 1. If the crankcase 2 is vented by means of the full-load crankcase ventilation 24 and thereby during full-load operation of the internal combustion engine 1, the second suction medium flows in the fourth flow direction illustrated by the arrow 21 through the full-load path 25 and thus through the suction line 46.With respect to the second flow direction of the second gas, illustrated by arrow 21, the oil separator 23 is arranged upstream of the suction jet pump 19 and, for example, downstream of the crankcase 2 in the suction line 46, so that the second suction medium flows through the oil separator 23 on its way from the crankcase 2 to the suction jet pump 19. The oil separator 23 is also referred to as a full-load separator (FLA). A first return line is designated 37. Via the first return line 37, the oil separated from the second gas by the oil separator 23 can be guided, for example, back into the crankcase 2 and / or into an oil pan of the internal combustion engine 1.

[0033] It can be seen that the full-load path 25 comprises the suction line 46 and thus the oil separator 23, the suction jet pump 19, and the mixture line 20. The part-load crankcase ventilation 35 has a vent line 39, so that the part-load path 36 comprises the vent line 39. The second gas or a third gas can be discharged from the crankcase 2 via the vent line 39, particularly during part-load operation of the internal combustion engine 1, wherein a further oil separator 38, provided in particular in addition to the oil separator 23, is arranged in the vent line 39. The oil separator 38 is thus a part-load separator (TLA), by means of which any oil contained in the second or third gas flowing through the vent line 39 or the part-load path 36, respectively, is separated, particularly during part-load operation of the internal combustion engine 1.A second return line 40 is provided, by means of which the oil separated by the oil separator 38 can be discharged from the oil separator 38 and, for example, guided, in particular returned, into the crankcase 2 and / or into the oil pan and / or into a cylinder head of the internal combustion engine 1. Downstream of the oil separator 38, the vent line 39 or the partial load path 36 can introduce the purified gas, in particular via check valves 41, into the intake tract 4 and / or directly into the combustion chambers, in particular at a location downstream of the throttle valve 27.It can be seen that the suction line 46 and the ventilation line 39 and thus the full-load path 25 and the partial-load path 36 have a common line section 42, via which gas is discharged from the crankcase 2 both when the crankcase 2 is vented by means of the full-load crankcase ventilation 24 in full-load operation of the internal combustion engine 1 and when the crankcase 2 is vented by means of the partial-load crankcase ventilation 35 in partial-load operation of the internal combustion engine 1.

[0034] The aforementioned purge air flow is described below. Particularly during partial load, i.e., partial load operation, of the internal combustion engine 1, the purge air flow can develop or be established. This purge air flow is formed by air from the intake tract 4 and flows or is guided from the supply point VS or from the branch point AZ1 via the supply line 29, the suction jet pump 15, the mixture line 16, and the length range L2 to the suction jet pump 19. The purge air flow is thus discharged from the mixture line 16 at the connection point V and introduced into the length range L2. It can flow through the length range L2 in the fifth flow direction, illustrated by arrow 22, opposite the fourth flow direction, and thus flow to the suction jet pump 19.

[0035] In Fig. 1, an arrow 43 illustrates a sixth flow direction in which the second suction medium flows through the suction line 46 and the oil separator 23 on its way from the crankcase 2 to the suction jet pump 19. A seventh flow direction opposite to the sixth flow direction is illustrated by an arrow 44. The aforementioned purge air flow can flow from the suction jet pump 19 in the seventh flow direction illustrated by the arrow 44 through at least a portion of the suction line 46 and thus flow via the portion of the suction line 46 to the oil separator 23. From the oil separator 23, for example, the purge air flow can flow through the return line 37 and flow into the crankcase 2 via the return line 37.It can be seen that the purge air flow can be introduced or is introduced into the crankcase 2 via the supply line 29, the suction jet pump 15, the mixture line 16, the length range L2, the suction jet pump 19, at least part of the suction line 46 and the oil separator 23, as well as, in this case, the return line 37, whereby the crankcase 2 can be purged and thus ventilated. Thus, for example, an additional purge air line for purging the crankcase 2 can be dispensed with.

[0036] In the exemplary embodiment shown in Fig. 1, however, an additional purge air line is shown as an example and designated 45. The purge air line 45 is fluidly connected to the intake tract 4 at a first purge air point LS1 and fluidly connected to the crankcase 2 at a second purge air point LS2. In the exemplary embodiment shown in Fig. 1, the purge air point LS1 is arranged upstream of the compressor 10 in the flow direction of the air flowing through the intake tract 4 and towards the combustion chambers, and in this case downstream of the air filter 6 and in this case also upstream of the introduction point E. For example, a check valve 47 is arranged in the purge air line 45. By means of the purge air line 45, at least a portion of the air flowing through the intake tract 4 can be branched off from the intake tract 4 at the purge air point LS1 and introduced into the purge air line 45 as purge air.The purge air introduced into the purge air line 45 can be introduced into the crankcase 2 via the purge air line 45 and the check valve 47, whereby the crankcase 2 can be ventilated, and thus purged. Thus, it is preferably provided that the check valve 47 opens, in particular automatically, toward the crankcase 2 and closes, in particular automatically, in the opposite direction, thus toward the purge air point LS1.

[0037] In principle, it would be conceivable that the supply point VS or the branch point AZ1 is arranged in the intake tract 4 downstream of the throttle valve 27 and in particular upstream of the combustion chambers.

[0038] Furthermore, the crankcase ventilation device 18 has a branch line 48 provided in addition to the supply lines 29 and 30 and in addition to the suction lines 31 and 46 as well as in addition to the mixture lines 16 and 20, by means of which a third part of the air from the inlet tract 4 can be introduced into the suction line 46, in particular bypassing the suction jet pump 19.

[0039] The feature that the third part of the air from the inlet tract 4 can be introduced into the suction line 46 by bypassing the suction jet pump 19 means that the air does not flow through the suction jet pump 19 on its way from the inlet tract 4 to the suction line 46 through the branch line 48, but only flows through the suction jet pump 19 after it has flowed out of the branch line 48 and into the suction line 46.

[0040] In the exemplary embodiment shown in Fig. 1, the branch point AZ1 is a connection point common to the supply lines 29 and 30, at which connection point the respective supply line 29, 30 is fluidically connected to the inlet tract 4. It can be seen that the branch point AZ1 is arranged downstream of the compressor 10 in the flow direction of the air flowing through the inlet tract 4 and, in the present case, for example, upstream of the throttle valve 27. The supply line 30 is fluidically connected to the suction jet pump 19 at a second connection point V2. The branch line 48 is fluidically connected to the inlet tract 4 at a third connection point V3 and to the suction line 46 at a fourth connection point V4. It can be seen that the branch point AZ1, the connection point V2, the connection point V3 and the connection point V4 are different from one another, i.e., spaced-apart points, and are therefore connection points.Thus, for example, at least the second portion of the air can be branched off from the inlet tract 4 at the branch point AZ1 and then guided to the suction jet pump 19 via the supply line 30 and introduced into the suction jet pump 19 at the connection point V2, whereby the suction jet pump 19 can be supplied with the second portion of the air as the second propulsion medium. Accordingly, the third portion of the air can be branched off from the inlet tract 4 at the connection point V3 via the branch line 48, guided to the suction line 46, and introduced into the suction line 46 at the fourth connection point V4.It can be seen that the connection point V3 is arranged upstream of the branching point AZ1 and also upstream of the compressor 10 in the flow direction of the air flowing through the intake tract 4, so that the air branched off from the intake tract 4 at the branching point AZ1 is air compressed by the compressor 10, and the air branched off from the intake tract 4 at the connection point V3 is not compressed by the compressor 10. Furthermore, it can be seen that the connection point V4 is arranged upstream of the connection point V2 and downstream of the oil separator 23 in the flow direction of the second suction medium flowing through the suction line 46. Furthermore, the connection point V4 is arranged downstream of the crankcase 2 in the flow direction of the second suction medium flowing through the suction line 46.

[0041] At least a length L3 of the suction line 46 is formed, for example, by a suction nozzle of a housing of the suction jet pump 19, wherein in the present case, for example, the connection point V4 is arranged on or in the suction nozzle. Thus, the branch line 48 opens into the suction nozzle at the connection point V4.

[0042] Furthermore, it can be seen from Fig. 1 that a valve device 49, designed for example as a control device, is arranged in the branch line 48, by means of which a quantity of the air originating from the inlet tract 4 flowing through the branch line 48 can be adjusted, in particular adjusted in a controlled manner.

[0043] With the crankcase ventilation device 18, it is possible to advantageously vent the crankcase 2 both in the upper load range and in the lower load range of the internal combustion engine 1, whereby, particularly in the upper load range, it is possible to prevent an excessive drop in the pressure prevailing in the crankcase 2, also referred to as the crankcase pressure. For this purpose, an excessively high performance of the suction jet pump 19 with regard to the suction of the second suction medium from the crankcase 2 can be avoided by means of the suction line 48 in the upper load range, thus preventing an excessive drop in the crankcase pressure in the upper load range. Furthermore, this allows a particularly high separation efficiency of the oil separator 23 to be achieved. List of Reference Symbols

[0044] internal combustion engine

[0045] crankcase

[0046] cylinder

[0047] Inlet tract

[0048] Arrow

[0049] Air filter

[0050] exhaust tract

[0051] Arrow

[0052] exhaust gas turbocharger

[0053] compressor

[0054] turbine

[0055] Wave

[0056] fuel tank

[0057] Tank ventilation device first suction jet pump first mixture line

[0058] Arrow

[0059] Crankcase ventilation device second suction jet pump second mixture line

[0060] Arrow

[0061] Arrow

[0062] Oil separator

[0063] Full-load crankcase ventilation

[0064] Full load path

[0065] Check valve

[0066] throttle

[0067] Intercooler first supply line second supply line first suction line

[0068] Tank vent valve

[0069] pressure sensor

[0070] Pressure sensor 35 partial load crankcase ventilation

[0071] 36 Partial load path

[0072] 37 Return line

[0073] 38 oil separators

[0074] 39 Ventilation line

[0075] 40 Return line

[0076] 41 Check valve

[0077] 42 line section

[0078] 43 Arrow

[0079] 44 Arrow

[0080] 45 Purge air line

[0081] 46 second suction line

[0082] 47 Check valve

[0083] 48 branch line

[0084] 49 Valve device

[0085] E Discharge point

[0086] V Connection point

[0087] V2 second connection point

[0088] V3 third connection point

[0089] V4 fourth connection point

[0090] L1 first length range

[0091] L2 second length range

[0092] L3 third length range

[0093] LS1 purge air point

[0094] LS2 purge air point

[0095] AZ1 junction

[0096] AZ2 junction point VS supply point

Claims

Patent claims 1. Internal combustion engine (1) for a motor vehicle, comprising: - a crankcase (2); - an inlet tract (4) through which air can flow; and - a crankcase ventilation device (18), which has: o a suction jet pump (19), to which at least part of the air from the inlet tract (4) can be supplied for venting the crankcase (2), so that for venting the crankcase (2) by means of the suction jet pump (19) using the air supplied to the suction jet pump as the driving medium for the suction jet pump (19), a gas can be sucked in as the suction medium from the crankcase (2); o a supply line (30), via which the suction jet pump (19) can be supplied with the driving medium; and o a suction line (46), via which the suction medium can be sucked in from the crankcase (2) and conveyed towards it by means of the suction jet pump (19); characterized by a branch line (48) provided in addition to the supply line (30) and in addition to the suction line (46), by means of which at least part of the air from the inlet tract (4) can be introduced into the suction line (46).

2. Internal combustion engine (1) according to claim 1, characterized in that: - the supply line (30) is fluidically connected to the inlet tract (4) at a first connection point (AZ1) and to the suction jet pump (19) at a second connection point (V2); and - the branch line (48) is fluidically connected to the inlet tract (4) at a third connection point (V3) different from the first connection point (AZ1) and to the suction line (46) at a fourth connection point (V4) different from the second connection point (V2).

3. Internal combustion engine (1) according to claim 2, characterized in that the third connection point (V3) is arranged upstream of the first connection point (AZ1) in the flow direction of the air flowing through the intake tract (4).

4. Internal combustion engine (1) according to claim 2 or 3, characterized in that the first connection point (AZ1) is arranged in the flow direction of the air flowing through the inlet tract (4) downstream of a compressor (10) arranged in the inlet tract (4) for compressing the air flowing through the inlet tract (4).

5. Internal combustion engine (1) according to claims 3 and 4, characterized in that the third connection point (V3) is arranged upstream of the compressor (10) in the flow direction of the air flowing through the inlet tract (4).

6. Internal combustion engine (1) according to one of claims 2 to 5, characterized in that the fourth connection point (V4) is arranged upstream of the second connection point (V2) in the flow direction of the gas flowing through the intake line (46).

7. Internal combustion engine (1) according to one of claims 2 to 6, characterized in that the fourth connection point (V4) is arranged downstream of the crankcase (2) in the flow direction of the gas flowing through the intake line (46).

8. Internal combustion engine (1) according to one of the preceding claims, characterized in that at least one length region (L3) of the suction line (46) is formed by a suction nozzle of a housing of the suction jet pump (19), wherein the branch line (48) opens into the suction nozzle.

9. Internal combustion engine (1) according to one of the preceding claims, characterized in that a valve device (49) is arranged in the branch line (48), by means of which a quantity of air flowing through the branch line (48) originating from the inlet tract (4) can be adjusted.

10. Motor vehicle with an internal combustion engine (1) according to one of the preceding claims.

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