EP2815089B1 - Crankcase breather device - Google Patents

Description

The present invention relates to a vehicle, preferably a road vehicle.

Most motor vehicles are equipped with an internal combustion engine, which usually provides for the drive of the vehicle. Such an internal combustion engine, preferably when it is designed as a piston engine, has a crankcase. In the crankcase is a crankshaft, which is connected via connecting rods with pistons of the individual cylinders of the internal combustion engine. Leakages between the pistons and the associated cylinder walls result in a blow-by gas flow through which blow-by gas passes from the combustion chambers into the crankcase. To avoid undue overpressure in the crankcase modern engines are equipped with a crankcase ventilation device to dissipate the blow-by gases from the crankcase. To reduce pollutant emissions, the blow-by gas is usually supplied to a fresh air system of the internal combustion engine using the crankcase ventilation device, which supplies the combustion chambers of the internal combustion engine with fresh air. In the crankcase there is an oil mist, so that the blow-by-gas carries oil with it. To reduce oil consumption, a crankcase ventilation device usually has an oil separator and preferably an oil return, which returns the separated oil to the crankcase.

In crankcase ventilation systems, passive systems can basically be distinguished from active systems. Passive systems use the pressure difference between the crankcase and the negative pressure in the fresh air system to drive the blow-by gas. The negative pressure in the fresh air system varies greatly depending on the operating condition of the Internal combustion engine. In this case, operating conditions may occur in which the available pressure difference is insufficient to dissipate enough blow-by gas. Furthermore, each oil separation device has a flow resistance for the blow-by gas, which makes the discharge of blow-by gas difficult. In contrast, active systems operate with a conveyor for driving the blow-by gas, so that always sufficient pressure difference can be provided to dissipate the required amount of blow-by gas from the crankcase. Also, in an active system, the flow resistance of the respective oil separator can be easily overcome. In active systems, however, the installation cost due to the separate conveyor is disadvantageous because a separate conveyor is associated with correspondingly high costs.

Oil separators work on different principles. Inertial separators are known, such as cyclone separators, impactors and centrifugal separators, as well as filter devices and electrostatic precipitators. A crankcase ventilation device, which operates with an oil separator designed as an impactor is, for example, from WO 2009/080492 A2 known.

From the WO 2002/44530 A1 For example, a vehicle is known which is equipped with an internal combustion engine having a crankcase, with a crankcase ventilation device, which has at least one oil separator and a separate oil-carrying line, and with a conveyor for driving a different from blow-by gas fluid. In the known vehicle, the conveyor is formed by a compressor of an exhaust gas turbocharger, which promotes charge air to the engine. A part of the charge air is supplied to a turbine, which is housed in a housing of the oil separator and therein for driving a rotor of a Centrifugal separator of Ölabscheideeinrichtung serves. A suction line of the crankcase ventilation device is connected to the housing of the oil separator. Another line carries the cleaned blow-by gas away from the housing of the oil separator.

The present invention is concerned with the problem of providing for a vehicle of the type mentioned an improved embodiment, which is characterized in particular by an inexpensive feasibility. At the same time, a high efficiency with regard to the oil separation effect should be realized.

This problem is solved in the present invention, in particular by the subject of the independent claim. Advantageous embodiments are the subject of the dependent claims.

The invention is based on the general idea of basically configuring the crankcase ventilation device as an active system, wherein an already existing on the vehicle conveyor is used to drive the blow-by gas, ie a conveyor on the vehicle by a blow-by gas drives different fluid. Thus, according to this proposal, an active system can be realized without having to provide a separate, additional conveyor on the vehicle. In this way, the already existing conveyor receives a double function. Furthermore, no additional space for accommodating an additional conveyor is required because only a suitable fluidic interconnection must be provided, which manages with comparatively little space.

The crankcase ventilation device has a suction line, which according to the invention connects the crankcase with a suction side of the conveyor. In this way, the blow-by gas is driven or sucked by a negative pressure generated by the conveyor at the suction side.

Additionally or alternatively, a pressure line of the crankcase ventilation device connect a pressure side of the conveyor with the crankcase or with a fresh air system of the internal combustion engine. The conveyor thus promotes the sucked blow-by gas either back to the crankcase or the fresh air system, whereby the blow-by gas is supplied together with the fresh air combustion in the internal combustion engine.

According to the invention, it is provided that the aforementioned suction line contains the oil separation device and is connected downstream thereof with a fresh air system of the internal combustion engine. Furthermore, the crankcase ventilation device according to the invention is equipped with a control device which allows a dependent of the current pressure in the fresh air in the region of the connection with the suction line control of a switching valve for controlling the connection between the suction line and conveyor. In other words, the suction of blow-by gas by means of the conveyor is activated in the simplest case only if an intake by the negative pressure in the fresh air line is not sufficient for this purpose. Thus, the conveyor need not be permanently used to drive the blow-by gas. In particular, therefore, the crankcase ventilation device can be switched depending on demand between a passive operation and an active operation.

In particular, this can be provided a fluidically connecting the crankcase with the fresh air system vent line. Advantageously, in the vent line in addition to the above Ölabscheideeinrichtung or alternatively arranged such Ölabscheideeinrichtung. This means that the blow-by gas in principle via the crankcase with the suction side of the conveyor tion connecting suction line and can connect via the connecting the crankcase with the fresh air system vent line from the crankcase, wherein in both cases, a separation of the contained oil by means of the respective associated oil separator.

Preferably, the vehicle is configured such that the blow-by gas can pass through the suction line or via the vent line from the crankcase, whereby combined variants are conceivable. For this purpose, in each case a control member or switching valve, such as a valve and the like, may be provided, which regulates the suction of the blow-by gas by means of the conveyor or the flow of the blow-by gas via the vent line, wherein the control members or switching valves advantageously communicate with a controller and are controlled by this. Thus, the venting can actively via the Saugleileitung fed again to the crankcase and thus cleaned again. A second part is fed into the fresh air system. By this feedback, the impurities supplied to the fresh air system can be reduced and the crankcase internal pressure can be kept constant.

According to another advantageous embodiment, the oil separation device may be arranged in the pressure line. This makes it possible, in particular, also to deposit oil particles, which are added to the blow-by gas flow in the region of the conveyor.

According to an advantageous development, a bypass line for bypassing the Ölabscheideeinrichtung be provided, which connects the pressure line between the conveyor and the Ölabscheideeinrichtung with the crankcase and which contains a pressure control valve. In the event that a particularly large amount of blow-by gas must be removed, which precludes too great a flow resistance in the oil separator, the bypass allows relief, so that for safety reasons, the oil separator can be bypassed. As the bypass leads to the crankcase, no oil was able to escape into the environment.

According to another advantageous embodiment, the conveyor may drive the fluid other than the blow-by gas in a main flow while driving the blow-by gas in a bypass flow, which may in particular be throttled. In this way, the main function of the conveyor remains the drive of the different from the blow-by gas fluid, as compared to only a relatively small amount of blow-by gas must be driven.

An embodiment is preferred in which the oil separation device is designed as an impactor or has at least one such impactor. An impactor is distinguished from other separators by an extremely simple structure, which manages without moving parts. Furthermore, an impactor is virtually maintenance free. Since a conveyor is used, the blow-by gas flow can be optimally dimensioned for an impactor, whereby a sufficiently high separation efficiency can be realized. The impactor may in particular be a high-pressure impactor.

Further, the respective Ölabscheideeinrichtung may have an oil reservoir or oil collector, in which the separated from the blow-by gas oil can be collected. The oil thus collected can then flow continuously or in the presence of favorable pressure conditions, in particular by means of the oil return, to the crankcase.

In an advantageous embodiment, the crankcase ventilation device may comprise an injector pump, which may also be referred to as a suction jet pump. Such an injector pump has a working fluid inlet, a suction fluid inlet, and a mixture outlet. The fluid driving the injector pump is the working fluid, it enters the working fluid inlet and the mixture outlet. In this case, the working fluid is usually passed through a nozzle, preferably a Laval nozzle, to generate a negative pressure in the working fluid flow. This negative pressure is connected to the Saugfluideingang over which any fluid is sucked and mixed with the working fluid, so that the sucked fluid enters the suction fluid inlet and also exits at the mixture outlet together with the working fluid. Such an injector pump thus operates with fluid-dynamic forces and does not require an external mechanical drive, such as a motor, belt drive or the like.

Appropriately, the working fluid input can now be connected via a supply line to the pressure side of the conveyor, while the suction fluid inlet is connected via a suction line to the crankcase. The mixture outlet is then suitably connected via a return line to the crankcase or to the fresh air system of the internal combustion engine. In such an embodiment, therefore, the different from the blow-by gas fluid, at least in the extent of a partial flow, for sucking the blow-by gas, in which case the mixture of the blow-by gas and the blow-by gas different fluid, which is preferably a gas, the crankcase or the fresh air system is supplied. The current required for driving the blow-by gas or partial flow of the different from the blow-by gas fluid is thus treated downstream of the injector as the blow-by gas itself.

The oil separation device is preferably arranged upstream of the suction fluid inlet of the injector pump. This has the advantage that the oil has already been separated from the blow-by gas reaching the injector pump. In addition, possibly passing through the Ölabscheideeinrichtung passing oil or oil droplets can be reduced by means of the Injektorpumpe and in particular atomized, so that the influences of the oil downstream of the injector be reduced. However, it is also possible to arrange the Ölabscheideeinrichtung downstream of the mixture output of the Injektorpumpe.

Particularly advantageous is an embodiment in which at least a partial flow of the conveyed by the conveyor, different from the blow-by gas fluid of the oil separation device is supplied. As a result, the fluid actually conveyed by the delivery device and different from the blow-by gas can also be cleaned of impurities.

Advantageously, the fluid other than the blow-by gas is a gas, in particular air. This simplifies the return of a mixture of said gas and blow-by gas to the crankcase and the fresh air system.

According to a further embodiment, a circulation conveyor may be provided in the vent line or in the suction line, which serves for the circulation of the blow-by gas between the crankcase and the oil separator arranged downstream of the circulation conveyor. For this purpose, the Ölabscheideeinrichtung is additionally fluidly connected by means of a different connection from the vent line connection with the crankcase, the latter line may be in particular the oil return. This serves in particular the purpose of allowing the return of the oil collected in the oil reservoir of the oil separator to the crankcase pressure-dependent. For example, the collected oil may return to the crankcase when the pressure in the blow-by gas in the crankcase is less than the pressure downstream of the oil separator.

According to a particularly advantageous embodiment, the conveyor may be part of a pneumatic brake system of the vehicle. A pneumatic brake system works with pneumatic pressure to drive brake cylinders. This pneumatic pressure is usually provided by means of a pneumatic conveyor. To ensure that the conveyor does not have to be operated permanently, a pneumatic brake system expediently works with at least one pressure accumulator. For cases in which the conveyor is not used to charge the pressure accumulator, the conveyor can be used to drive blow-by gas. It is also conceivable to connect the pressure line to the pressure accumulator.

Alternatively, the conveyor may be part of a compressed air system of the vehicle. In modern vehicles, especially in commercial vehicles, all kinds of systems can be operated with compressed air, such as pneumatic struts.

Alternatively to such an overpressure system, the conveyor may be part of a vacuum system of the vehicle. An example of this is a vacuum pump of a brake booster of the vehicle, which may be designed in particular as a load vehicle or a commercial vehicle.

A compressed air system of the vehicle may also be provided in the supply devices of the internal combustion engine. In a preferred embodiment, the conveyor is an exhaust gas turbocharger of the internal combustion engine. The exhaust gas turbocharger is driven by the exhaust gas of the internal combustion engine and compresses the air in the fresh air system by means of a compressor. The pressure side of the conveyor thus corresponds to the compressor side of the exhaust gas turbocharger, wherein the corresponding connection with the pressure side in this case can take place via the fresh air system, because the compressor is usually arranged in the fresh air system. In this case, therefore, the different from the blow-by gas fluid is the internal combustion engine to be supplied air. This has the advantage, for example, that a direct or indirect relationship between the application of air to the internal combustion engine and thus of the blow-by gas on the one hand and the drive of the blow-by gas in the crankcase device on the other hand can be created.

The gas other than the blow-by gas may also contain impurities, for example in the form of oil droplets. These contaminants are separated from the volumetric flow by the oil separator of the crankcase breather. Only the impurities, which through the Ölnebelabscheideeinrichtung pass through, are added to the fresh air. So a reduced pollutant emissions is realized. Furthermore, the volume flow containing the impurities is not discharged uncontrollably into the environment.

According to a further alternative, the conveyor may be a component of a tank ventilation device of the vehicle. In modern motor vehicles, care must be taken to prevent fuel vapor from entering the environment from the fuel tank. For this purpose, tank ventilation devices can be used, which can in principle be equipped with a conveyor, for example, to be able to check the tightness of the ventilation system or the fuel tank as part of a diagnosis can. By using the conveyor of the tank ventilation, it is particularly possible to mix fuel vapors the blow-by gas and dispose of the fresh air system.

In a further variant, the conveyor may be part of a diagnostic device of the fuel tank and in particular be designed as a diagnostic pump. By means of the diagnostic device is a diagnosis, in particular the tightness of the fuel tank of the vehicle, such as a pressure diagnosis and the like. In particular, the conveyor can thus be part of such a pressure system or vacuum system.

According to another embodiment, the conveyor may be part of a diagnostic device of the crankcase ventilation system or the crankcase ventilation device, wherein the diagnostic pump introduces a test pressure into the crankcase ventilation device, in particular in lines of the crankcase ventilation device, and over the pressure curve within the crankcase ventilation device, the tightness of the crankcase ventilation device is checked. The test pressure can therefore be an overpressure or a negative pressure.

Other important features and advantages of the invention will become apparent from the dependent claims, from the drawings and from the associated figure description with reference to the drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

Preferred embodiments of the invention are illustrated in the drawings and will be described in more detail in the following description, wherein like reference numerals refer to the same or similar or functionally identical components.

Fig. 1-9

jeweils eine stark vereinfachte, schaltplanartige Prinzipdarstellung eines Kraftfahrzeugs mit Brennkraftmaschine und Kurbelgehäuseentlüftungseinrichtung, bei verschiedenen Ausführungsformen.

Show, in each case schematically,

Fig. 1-9

in each case a greatly simplified schematic diagram of a motor vehicle with internal combustion engine and crankcase ventilation device, in various embodiments.

According to the Figures 1-9 comprises a motor vehicle 1, which is preferably a road vehicle, designed as a piston engine internal combustion engine 2, a fresh air system 3, an exhaust system 4 and a Kurbelgehäuseentlüftungseinrichtung 5. The vehicle 1 is in the characters 1-9 greatly simplified and shown only in the area of the crankcase ventilation device 5.

The internal combustion engine 2 comprises a crankcase 6, in which a crankshaft 7 is arranged, which is connected via at least one connecting rod 8 with at least one piston 9, which is arranged to be adjustable in stroke in an associated cylinder 10 of the internal combustion engine 2. The respective cylinder 10 encloses a combustion chamber 11. Associated gas exchange valves, namely at least one inlet valve 12 and at least one outlet valve 13 are accommodated in a cylinder head 14. According to an arrow 15, during operation of the internal combustion engine 2, blow-by gas can pass from the respective combustion chamber 11 past the respective piston 9 into the crankcase 6. Likewise, the blow-by gas can pass through internal paths into the cylinder head 14.

The fresh air system 3 serves to supply the combustion chambers 11 with fresh air, which is sucked in from an environment 16 for this purpose. The exhaust system 4 leads combustion exhaust gases away from the combustion chambers 11 and through at least one exhaust gas treatment device 20 in the direction of the environment 16. Furthermore, an exhaust gas recirculation 21 may be provided returns a portion of the combustion exhaust gases from the exhaust system 4 to the fresh air system 3. The exhaust gas recirculation 21 expediently contains an exhaust gas recirculation cooler 22, which may be connected to a cooling circuit of the internal combustion engine 2.

The crankcase ventilation device 5 comprises at least one Ölabscheideeinrichtung 23, with the aid of which in the blow-by gas entrained oil from the blow-by gas stream can be separated and an oil return 24 again the crankcase 6 and a sump 25 can be supplied.

The vehicle 1 is also equipped with a conveyor 26, which serves in the vehicle 1 for driving a different from blow-by gas fluid. This conveyor 26 is now used in addition to driving the blow-by gas within the crankcase ventilation device 5. The respective conveyor 26 is expediently equipped with its own drive motor 27, which is preferably an electric motor and can be controlled independently of the operation of the internal combustion engine 2. In principle, however, a mechanical drive coupling between the internal combustion engine 2 and the conveyor 26 is conceivable, for example via a belt drive.

The conveyor 26 may be a pump which generates an overpressure and / or underpressure. The conveyor 26 may thus be, for example, an already existing in the vehicle 1 vacuum pump. Such a vacuum pump may in particular serve the brake booster of the vehicle 1 or be part of a brake booster of the vehicle 1.

The crankcase ventilation device 5 has in the embodiments of FIGS. 1 . 2 . 4 . 7 . 8th and 9 a pressure line 28 which connects a pressure side of the conveyor 26 with the crankcase 6. At the in FIG. 3 In the embodiment shown, the delivery device 26 is connected directly to the crankcase 6 on the pressure side.

At the in FIG. 1 In the embodiment shown, the crankcase ventilation device 5 is equipped with an injector pump 29. This comprises a working fluid inlet 30, a suction fluid inlet 31 and a mixture outlet 32. The injector pump 29 is integrated in the pressure line 28 so that the pressure line 28 from the working fluid inlet 30 to the mixture outlet 32 through the injector 29 passes. Thus, the fluid conveyed with the aid of the conveying device 26 and different from the blow-by gas serves as working fluid of the injector pump 29. The suction fluid inlet 31 is connected via a suction line 33 to the crankcase 6 or to the cylinder head 14. Additionally or alternatively, the suction fluid inlet 31 may be connected via a suction line 34 to a vent line 35 of the crankcase ventilation device 5, which expediently downstream of the throttle valve 19 leads from the crankcase 6 to the fresh air system 3. In that regard, the suction fluid inlet 31 is also connected via the suction line 34 indirectly via a portion of the vent line 35 to the crankcase 6. The section 36 of the pressure line 28 which leads back from the mixture outlet 32 to the crankcase 6 can also be referred to as the return line 36. In order to control the injector pump 29, a switching valve 38 is installed in the section 37 of the pressure line 28 leading from the conveyor 26 to the working fluid inlet 30, which can be controlled via a corresponding control, not shown here. The leading from the conveyor 26 to the working fluid inlet 30 section 37 of the pressure line 28 may also be referred to as supply line 37.

At the in FIG. 1 In the embodiment shown, the oil separation device 23 is preferably arranged in the ventilation line 35, wherein the suction line 34 is expediently connected downstream of the oil separation device 23 to the ventilation line 35. Downstream of this junction designated 39, the vent line 35 may suitably contain a pressure control valve 40. When the injector pump 29 is deactivated, which can be achieved, for example, by blocking the section 37 of the pressure line 28, ie the supply line 37, the negative pressure prevailing in the fresh air system 3 downstream of the throttle valve 19 can be used to blow-by the gases from the crankcase 6 to suck. In certain operating states of the internal combustion engine 2, however, in this, designated 41 connection area between the extraction line 35 and Fresh air system 3 insufficient negative pressure is available to achieve a satisfactory extraction of blow-by gas. For these states, the switching valve 38 is then actuated via the aforementioned control in order to activate the injector pump 29, so that it is possible to suck off via this blow-by gas.

Both FIGS. 1 to 3 and 7 to 9, the pressure control valve 40 is located between the connection point 39 and the vent line 35 connected to the fresh air system 3. As the volume flow exiting the oil separation device 23 increases, a larger volume flow is fed into the fresh air system 3. Thus, the crankcase internal pressure remains constant. Thus, in addition to the usually incurred blow-by gas and the promoted by the injector pump 29 into the crankcase gas cleaned and fed to the fresh air system 3. The guided via the suction line 34 in a circle gas volume is returned.

As in FIG. 1 illustrated, such a Ölabscheideeinrichtung 23 may additionally or alternatively be arranged in the suction line 33 and 34, respectively. Additionally or alternatively, it is possible to incorporate such a Ölabscheideeinrichtung 23 in the pressure line 28, and preferably in the section 36, ie in the return line 36. Furthermore, it is basically possible to integrate such an oil separation device 23 already in the injector pump 29.

In general, the oil separator 23 may be a centrifuge or a cyclone or a filter or an impactor. Likewise, combinations of the aforementioned different embodiments are conceivable. Particularly inexpensive is the realization of the oil separator 23 as an impactor. In particular, such an impactor can be particularly easily integrated into the injector pump 29 due to its compact design.

At the in FIG. 1 For example, the vehicle 1 is equipped with a pneumatic brake system or with a pneumatic suspension device or other systems that are operated with pneumatics. Typically, such a compressed air system 42 downstream of the conveyor 26 may have a compressed air tank 43. Upstream of the conveyor 26, an air filter 44 is usually arranged. The conveyor 26 may suck in air from the environment 16 and after the tank 43 the designated, not shown consumers according to an arrow 50 perform. Such compressed air consumers are for example air brakes, pneumatic springs or other compressed air units.

In the embodiments of the Figures 2-4 and 7 to 9, the two cumulative or alternatively existing suction lines 33, 34 connected to the suction side of the conveyor 26. The respective suction line 33, 34 may include a throttle 45. If the respective suction line 33, 34 also has an oil separation device 23, the throttle 45 is expediently arranged upstream of the separation device 23. In principle, the throttle 45 can also be arranged downstream of the oil separation device 23. So show the Figures 2 and 4 in each case a variant in which the throttle point 45 is arranged downstream of the Ölabscheideeinrichtung 23 in the pressure line 28. Alternatively, an embodiment is conceivable in which the throttle device 45 is structurally integrated into the oil separation device 23, namely upstream or downstream of the internal separation means, which are preferably again an impactor.

At the in FIG. 3 In the embodiment shown, the oil separation device 23 is again arranged in the ventilation line 35, namely upstream of the connection point 39, via which the suction line 34 is connected to the vent line 35. In this case, a throttle point 45 is arranged in the suction line 34 in order to limit the volume flow of blow-by gas to a predetermined value.

At the in FIG. 4 In addition, a bypass or a bypass line 46 can be seen, which enables a bypass of the oil separation device 23 arranged in the pressure line 28. At the in FIG. 4 In the embodiment shown, the pressure line 28 is connected to the fresh air system 3 via the connection point 41. A vent line 35, as in the variants of Figures 1-3 is missing from the in FIG. 4 shown embodiment. Thus, at the in FIG. 4 As shown variant, the suction line 34 is connected directly to the crankcase 6 and may include an oil separator 23, which may be provided in addition to or alternatively to the arranged in the pressure line 28 Ölabscheideeinrichtung 23. In the bypass line 46, a pressure control valve 47 is expediently arranged, which is designed here as a spring-loaded check valve.

In the embodiments of the Figures 2-4 the respective conveyor 26 is connected on the suction side via a corresponding connecting line 48 to the respective system to which the conveyor 26 is associated. This may be, for example, a tank ventilation device 49, with the help of a fuel tank 61, as he, for example, in the FIGS. 7 and 9 is shown, can be vented. In this case, 26 vaporous hydrocarbons can be aspirated from the fuel tank 61 via the conveyor 26 and perform the combustion in the combustion chambers 11 via the crankcase ventilation device 5 and ultimately via the fresh air system 3.

Suitably, the interconnection of the conveyor 26 takes place in such a way that it drives the fluid other than the blow-by gas, for example air or hydrocarbon-containing air, in a main flow while it drives the blow-by gas in a secondary flow, this secondary flow, like in the Figures 2 and 3 shown, preferably throttled. The main flow is at least twice as large as the sidestream.

Furthermore, in the embodiments of the FIGS. 1 . 2 and 4 provided that the conveyor 26 supplies the different from the blow-by gas fluid at least in the circumference of a partial flow of the oil separator 23, which is arranged for this purpose in the pressure line 28. Thus, it is also possible to deposit impurities contained in the fluid other than the blow-by gas which originate, for example, from the delivery device 26.

In FIG. 5 an embodiment is shown in which the conveyor 26 is formed by an exhaust gas turbocharger 51 of the internal combustion engine 2, which is arranged with its turbine 52 upstream of the exhaust gas treatment device 20 in the exhaust system 4 and with its compressor 53 upstream of the throttle valve 19 in the fresh air system 3. In addition, a charge air cooler 54 is arranged in the fresh air system 3 downstream of the compressor 53 and upstream of the throttle valve 19 in order to cool the air compressed by the compressor 53. The turbine 52 and the compressor 53 are drivingly connected to each other by means of a shaft 55, so that the turbine 52 driven by the exhaust gas of the internal combustion engine 2 drives the compressor 53 compressing the air in the fresh air system 3. In this respect, the portion of the fresh air system 3 between the compressor 53 and the throttle 19 of the pressure line 28 is further provided such injector 29, whose working fluid inlet 30 is connected by means of the supply line 37 downstream of the charging radiator 54 and upstream of the throttle valve 19 fluidly connected to the fresh air system 3 , Thus, the injector 29 is the particular of the compressor 53 compressed air of the fresh air system 3 driven. In addition, the suction line 33 connects the suction fluid inlet 31 of the injector pump 31 with the crankcase 6, while the mixture outlet 32 of the injector pump 31 is fluidically connected to the fresh air system 3 via the vent line 35 'at the connection region 41. A second vent line 35 "opens upstream of the connection area 41 in the first vent line 35 'to the common vent line 35. In the first suction line 33 and in the second vent line 35" such a Ölabscheideeinrichtung 23 is arranged, of which in each case such an oil return 24 to Swamp 25 of the crankcase 6 leads, wherein in the oil return 24 of the arranged in the suction line 33 Ölabscheideeinrichtung 23 additionally a throttle 45 is provided to limit the flow of the oil in the crankcase 6 and in the sump 25. Here, this Ölabscheideeinrichtung 23 is equipped with an oil reservoir 56, in which the separated oil can first be collected and then fed to the sump 25.

Thus, the blow-by gas from the crankcase 6 can pass both actively by means of the injector pump 29 and the conveyor 26 via the suction line 33 as well as passively via the second vent line 35 "In the latter case, however, there is a sufficient pressure difference between the connection area 41 and the crankcase 6. Accordingly, the active venting can be used only when such a pressure difference is not or not sufficiently present.This is provided in the supply line 37 and in the second vent line 35 "downstream of the oil separator 23 each such a control member 38th provided in the form of a switching valve 38, wherein alternatively or additionally pressure control valves 40 may be provided. In the case of the switching valve 38 arranged in the second vent line 35 ", it is likewise possible to arrange it upstream of the oil separator device 23. These switching valves 38 are connected to said controller or to a control unit other controller 58 communicatively connected, for example by means of cable 59, wherein the controller 58 can individually control the respective switching valve 38 to change any between the active and passive venting or a mixture thereof. In general, the control of the switching valves 38 is dependent on the said pressure conditions.

The use of the exhaust gas turbocharger 51 as a conveyor 26 has the particular advantage that with increasing loading load of the exhaust gas turbocharger 51, a larger amount of blow-by gas is generated because the cylinder 10 is subjected to higher pressure. At the same time, a greater power of the injector pump 29 is achieved at full load, so that an adapted ventilation of the crankcase 6 takes place. Accordingly, the volume flow of the blow-by gas decreases with reduced load, which also means a reduced line of the injector 29. Thus, the venting of the crankcase 6 is almost automatically adapted to the flow rate of the generated blow-by gas. Furthermore, for a sufficient drive of the injector pump 29, a comparatively small diversion of the charge air compressed by the exhaust gas turbocharger 51, in particular the charge air power, of approximately 5% is necessary.

FIG. 6 shows a further embodiment in which such oil separation device 23 is provided with such an oil reservoir 56 in the suction line 33. Upstream of the oil separator 23 there is further arranged a circulation conveyor 57 which delivers the blow-by gas from the crankcase 6 to the oil separator 23 where the contained oil is at least partially separated. Subsequently, part of the blow-by gas can flow back to the crankcase 6 via the oil return 24, so that a circulation of the blow-by gas is achieved. Here, an overpressure control valve 47 is arranged in the oil return 24, which prevents the backflow of the blow-by gas or the separated oil in particular when the pressure in the oil separator The flow of the oil from the Ölabscheideeinrichtung 23 and the oil reservoir 56 takes place in particular when the pressure downstream of the Ölabscheideeinrichtung 23 is higher than the pressure in the crankcase 6. The pressure downstream of the Ölabscheideeinrichtung 23, for example be determined by the performance of the injector 29, in particular the suction at the Saugfluideingang 31. In the variant shown with the dashed line of the connection of the oil separator 23 and the suction line 33, in which the Ölabscheideeinrichtung 23 and the suction line 33 are connected by means of the vent line 35 directly to the connection point 41 in the fresh air system 3, the pressure is downstream of the Ölabscheideeinrichtung 23 determined in particular by the pressure in the region of the connection point 41. Further, upstream of the circulation conveyor 57, a control member 38 is provided in the form of a switching valve 38 to vary the volume flow of the blow-by gas conveyed by the circulation means 47 and in particular to limit. For this purpose, the switching valve 47 is communicatively connected to said controller 58 or other control.

Fig. 7 shows a further embodiment in which the conveyor 26 is part of a diagnostic device 60 for diagnosing or checking the tightness of a fuel tank 61 of the vehicle 1. The diagnostic device 60 has a first diagnostic line 62 which opens into the pressure line 28 downstream of the conveyor 26 and a second diagnostic line 63 which opens into the suction line 34 upstream of the conveyor 26 and a third diagnostic line 64 which is fluidically connected to the fuel tank 61. The first diagnostic line 62, the second diagnostic line 63 and the third diagnostic line 64 are interconnected by means of a control member 38 and the control valve 38, the diagnostic lines 62, 63, 64 each with each other or all connect or vary these compounds and in particular can interrupt. Accordingly, the respective connection or the corresponding flow can also be throttled. The diagnosis of the fuel tank is preferably carried out in a state of low load or at a standstill of the internal combustion engine 2, in which relatively little or no blow-by gas is produced or obtained, wherein in the conveyor 26 promotes at least partial load in any case. To diagnose the fuel tank 61, the control valve 38 is actuated such that only the first diagnostic line 62 is connected to the third diagnostic line 64. Thus, in the fuel tank 61, an overpressure can be generated, which serves as a test pressure. Upon reaching any or predetermined overpressure in the fuel tank 61, the control valve 38 interrupts the connections between the diagnostic lines 62, 63, 64 in order to keep the overpressure in the fuel tank 61 stable. With the aid of a pressure measuring device 65, pressure monitoring is now carried out in the third diagnosis line 64 or in the fuel tank 61. In the present case, the pressure measuring device 65 is connected to the third diagnosis line 64. The pressure measuring device 65 may alternatively or additionally also be connected directly to the fuel tank 61 or arranged in the fuel tank 61. If the pressure determined by the pressure measuring device 65 does not change, or does not change substantially or only in an anticipated range, for example due to fuel consumption, then corresponding leaks can be ruled out. A change in pressure and in particular a pressure drop, for example above the expected range, however, indicates one or more leaks. Following the diagnosis, the control valve 38 can be actuated such that a venting of the fuel tank takes place or is continued. The tank ventilation device 49 is thus part of the diagnostic device 60 or vice versa.

Analogous to the in Fig. 7 illustrated embodiment is in Fig. 8 a further embodiment shown in which the diagnostic device 60 of the diagnosis of leakage or the detection of leaks of the crankcase ventilation device 5, in particular in the lines 34, 28, the oil separator 23rd and / or the pressure control valve 40, is used. For this purpose, the conveyor 26 introduces a different from the blow-by gas fluid in the crankcase ventilation device 5 and provides in the crankcase ventilation device 5, in particular in the suction line 34 and / or the vent line 35, for an overpressure. Alternatively, the conveyor 26 may also generate a negative pressure in the conduits 34, 35, and / or the pressure regulating valve 40 and / or the oil separator 23, whereby the test pressure is the generated negative pressure. For this purpose, the existing in the lines 34, 35, and / or the pressure control valve 40 and / or the Ölabscheideeinrichtung 23 gas volume is conveyed into the crankcase 6, whereby a negative pressure. Again, the diagnosis is preferably carried out at a low load condition of the internal combustion engine 2 or at a standstill of the internal combustion engine 2. In the case of overpressure is the different from the blow-by gas fluid in the present case to air from the environment 16 by an air line 66, which may be connected to the fresh air line 3 or may correspond to it, are conveyed by the conveyor 26 and can be introduced into the crankcase ventilation device 5. Within the air line 66, an air filter 44 and a control valve 38 are arranged. Immediately downstream and upstream of the crankcase 6, further control members 38 are arranged to build up or maintain said negative pressure in the suction line 34 and the overpressure line 28, respectively. For example, to generate the overpressure in the suction line 34 and / or the pressure line 28 and / or the pressure control valve 40 and / or the Ölabscheideeinrichtung 23, arranged in the air line 66 control member 38 is opened up in the suction line 34 and / or the pressure line 28th build up an overpressure. Subsequently, all the control members 38 in the lines 34, 28, operated in such a way that no flow into or out of the section to be examined is possible. Preferably, the pressure control valve 40 is closed, wherein alternatively or additionally, another control member 38 is provided in the vent line 35, which already before the generation of the Overpressure or negative pressure, in any case, but then also closed. In the section to be examined, the pressure measuring device 65 is arranged or the pressure measuring device 65 is connected to this section. Here, too, pressure fluctuations, in the case of overpressure, ie a decrease in pressure, point to a leak. In order to carry out a prognosis for the suction line 34 and the pressure line 28, the control members 38 are closed directly on the crankcase 6 and in the air line 66 and the pressure control valve 40 and / or the control member 28 in the vent line 35, for example after generating the overpressure. Thus, the pressure in the suction line 34 and the pressure line 28 is locked. If a pressure change, in particular a pressure decrease, is measured by means of the pressure measuring device 65 connected to the suction line 34 and / or the pressure line 28, this indicates a leak or leakage in the pressure line 28 or the suction line 34 , If the suction line 34 and the pressure line 28 to be tested separately for leaks, then the immediately suction side of the conveyor 26 arranged in the suction line 34 control member 38 is closed after the construction of the overpressure, so that a flow between the suction line 34 and the pressure line 28 is interrupted is. Accordingly, with the pressure measuring device 65 connected to the suction line 34, a corresponding diagnosis of the suction line 34 and / or a corresponding diagnosis of the pressure line 28 by means of the pressure measuring device 65 connected to the pressure line 28 can take place. If only the suction line 34 is to be examined for leaks, it is also sufficient to close the suction side of the conveyor 26 arranged control member 38 instead of the pressure side of the conveyor 26 arranged control member 38 to build in the suction line 34, an overpressure. Subsequently, the control members 38 are closed immediately downstream of the crankcase 6 and in the air line 66. Thereafter, the diagnosis is carried out by means of the pressure measuring device 65.

In Fig. 9 a further embodiment of the vehicle 1 is shown. Unlike in Fig. 7 1, a negative pressure is generated here for the diagnosis of the fuel tank 61 in the fuel tank 61 and the pressure changes are subsequently monitored by means of the pressure measuring device 65, in which case an increase in pressure indicates a leakage. For this purpose, the diagnostic device 60 to the fuel tank 61 connected to the third diagnostic line 64 and the suction side of the conveyor opening second diagnostic line 63, which are connected to each other by means of the control member 38. For diagnosis, this control member 38 is opened, whereby the conveyor 26 promotes in particular steam-like hydrocarbons from the fuel tank 61. In this case, the control member 38 is opened so far that in the fuel tank 61, a negative pressure, whereupon the control member 38 of the diagnostic device 60 is closed. Subsequently, the diagnosis can be made as explained above. After the diagnosis, the control member 38 can be opened so far that a normal venting of the fuel tank 61 takes place. In this case too, the tank venting device 49 corresponds to the diagnostic device 60 or vice versa.

In the in the Fig. 1 to 3 As well as FIGS. 7 to 9, it can be seen that the vent line 35 is connected to the connection point 41 on the fresh air line 3. In addition, the suction line 34, via which the blow-by gas is sucked out of the crankcase, is connected on the input side to the connection point 39 on the ventilation line 35, with which the ventilation line 35 is fluidically connected to the fresh air line 3. This connection point 39 is arranged between the oil separator 23 and the pressure control valve 40. As a result, the blow-by gas extraction at a sufficiently low pressure conditions in the fresh air line 3 also passively, that is done without support of the conveyor 26. This can also be used to active blow-by gas extraction by means of the conveyor 26 and the passive blow-by-gas extraction can be combined as desired. For this purpose, in particular, the switching valve 38 is used, which regulates the connection between the suction line 33, 34 and the conveyor 26 and this can interrupt in particular. In addition, for this purpose, the pressure control valve 40 and / or at least one of the throttle 45 and / or the throttle valve 19 may be used. These are controlled, for example, by the controller 58 or other controller. In addition, the vehicle 1 may have at least one pressure measuring device in order to determine the pressure in the corresponding areas, such as in the fresh air line 3 and / or in the crankcase 6, which can be transmitted to the controller 58.

Claims (13)

1. A vehicle (1),

   - having an internal combustion engine (2), which has a crankcase (6),

   - having a crankcase ventilation device (5), which has at least one oil separating device (23) and an oil return (24) that feeds separated oil back to the crankcase (6),

   - having a conveying device (26) for driving a fluid other than blow-by gas,

   - wherein the conveying device (26) is moreover used to drive the blow-by gas in the crankcase ventilation device (5),

   - wherein an intake line (33, 34) of the crankcase ventilation device (5) connects the crankcase (6) to an intake side of the conveying device (26),

   - the intake line (33, 34) contains the oil separating device (23) and is connected downstream of the same to a fresh air system (3) of the internal combustion engine (2),

   - wherein a control device is provided, which allows an actuation of a control member (38) depending on the current pressure in the fresh air in the region of the connection (39) to the intake line (34) to control the connection between the intake line (34) and the conveying device (26).
2. The vehicle according to Claim 1,
   characterised in that
   a pressure line (28) of the crankcase ventilation device (5) connects a pressure side of the conveying device (26) to the crankcase (6) or to a fresh air system (3) of the internal combustion engine (2).
3. The vehicle according to Claim 1 or 2,
   characterised in that
   the oil separating device (23) is arranged in the pressure line (28).
4. The vehicle according to Claim 3,
   characterised in that
   a bypass line (46) is provided to bypass the oil separating device (23), which bypass line connects the pressure line (28) between the conveying device (26) and the oil separating device (23) to the crankcase (6) and contains an overpressure regulation valve (47) .
5. The vehicle according to any one of Claims 1 to 4, characterised in that
   the conveying device (26) drives the fluid other than the blow-by gas in the main stream, while it drives the blow-by gas in the secondary stream, which is preferably throttled.
6. The vehicle according to any one of Claims 1 to 5, characterised in that
   the oil separating device (23) is configured as an impactor or has an impactor.
7. The vehicle according to any one of Claims 1 to 6, characterised in that

   - the crankcase ventilation device (5) has an injector pump (29), which has a working fluid inlet (30), a suction fluid inlet (31) and a mixed outlet (32),

   - wherein the working fluid inlet (30) is connected via a supply line (37) to the pressure side of the conveying device (26),

   - wherein the suction fluid inlet (31) is connected via an intake line (33, 34) to the crankcase (6),

   - wherein the mixed outlet (32) is connected via a return line (36) to the crankcase (6) or to a fresh air system (3) of the internal combustion engine (2).
8. The vehicle according to any one of Claims 1 to 7, characterised in that
   at least one part-stream of the fluid other than the blow-by gas that is conveyed by the conveying device (26) is fed to the oil separating device (23).
9. The vehicle according to any one of Claims 1 to 8, characterised in that

   - the conveying device (26) is a component of a pneumatic braking system of the vehicle (1), or

   - the conveying device (26) is a component of a compressed air system (42) of the vehicle (1), or

   - the conveying device (26) is a component of a tank ventilation device (49) of the vehicle (1), or

   - the conveying device (26) is a component of a diagnostic device (60), in particular for diagnosing a fuel tank (61) or the crankcase ventilation device (5), or

   - the conveying device (26) is an exhaust gas turbocharger (51) of the internal combustion engine (2).
10. The vehicle according to any one of Claims 1 to 9, characterised in that
    the vehicle (1) has two such oil separating devices (23), which are each connected fluidically to the crankcase (6) via such an oil return (24), wherein

    - one of the oil separating devices (23) is arranged in the intake line (33, 34) or in the supply line (37),

    - the other oil separating device (23) is arranged in a ventilation line (35) that fluidically connects the crankcase (6) to the fresh air system (3).
11. The vehicle according to Claim 10,
    characterised in that
    in each case a switching valve (38) is arranged in the supply line (37) or in the intake line (33, 34) and in the ventilation line (35), wherein the switching valves (38) can be controlled by means of a control system (58).
12. The vehicle according to any one of Claims 1 to 11, characterised in that
    the oil separating device (23) has an oil container (56) for collecting oil separated out of the blow-by gas.
13. The vehicle according to any one of Claims 1 to 12, characterised by
    a circulating conveying device (57) for circulating blow-by gas between the crankcase (6) and the oil separating device (23).

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