DE102015205557B4 - Internal combustion engine and method for operating an internal combustion engine - Google Patents

Abstract

Internal combustion engine (1), with - at least one combustion chamber (3), and - one via a Beiblaspfad (7) with the at least one combustion chamber (3) communicating crankcase (5), wherein - the internal combustion engine (1) a venting path (11) for Ventilation of the crankcase (5) having a first end (13) of two ends (13, 15) of the venting path (11) opens into the crankcase (5), wherein - in the venting path (11) between the first end ( 13) and a second end (15) of the two ends (13, 15) an oil separation device (17) is arranged, wherein the oil separation device (17) is designed as an actively driven device, characterized in that - the oil separation device (17) has a controllable Drive (25), wherein the internal combustion engine (1) comprises a control device (31) which is adapted to the controllable drive (25) depending on a pressure in the crankcase (5) to control.

Description

The invention relates to an internal combustion engine and a method for operating an internal combustion engine.

In internal combustion engines having at least one combustion chamber and a crankcase, the crankcase typically communicates via a Beiblaspfad with the combustion chamber such that during combustion in the combustion chamber due to the greatly increased pressure combustion gases along the Beiblaspfads can get past the combustion chamber seals in the crankcase. This phenomenon is also referred to as "blow-by" and the gases entering the crankcase are referred to as "blow-by gases". For venting the crankcase, a venting path is provided in which an oil separation device is arranged to separate with the blow-by gases entrained or co-funded lubricating oil. Such Ölabscheideeinrichtungen typically have filters that are subject to contamination and are therefore prone to maintenance. In addition, conventional oil separator devices have an improved deposition behavior, wherein contamination and sooting of components arranged downstream of the oil separator are possible by insufficient oil separation. This is particularly problematic in cases in which the venting path opens into a charging path for supplying combustion air or a combustion air-fuel mixture into the combustion chamber, wherein elements of the charging path can be contaminated or spoil. Sometimes it is necessary to maintain or regulate the pressure in the crankcase at least below a certain level due to requirements of the internal combustion engine. This is only possible with existing systems for venting and oil separation difficult and in an improved manner, wherein a suction or conveying behavior of the venting path depends in particular on a degree of contamination of an air filter and / or a Ansaugunterdruck a turbocharger, when the venting path opens into the charging path.

From the German patent DE 198 03 872 C2 is a ventilation device for a crankcase of an internal combustion engine with a rotatably mounted about an axis of rotation and driven driven centrifugal oil separator.

From the German patent application DE 100 44 615 A1 is a venting device for a crankcase of an internal combustion engine with a centrifugal oil separator forth, which is designed as a Tellerseparator.

From the German patent application DE 100 63 903 A1 goes out a centrifuge for cleaning the lubricating oil of an internal combustion engine, which is used at the same time for cleaning crankcase gases.

From the German patent application DE 102 51 940 A1 is a centrifugal separator for the separation of oil from a gas stream, especially in the venting of the crankcase of an internal combustion engine forth.

From the German patent application DE 103 23 261 A1 is a centrifugal oil separator for blow-by gases of an internal combustion engine forth, wherein a drive shaft of a rotating component is connected via a mechanical coupling with a driven by a crankshaft of the internal combustion engine gearbox.

From the German patent application DE 10 2007 030 277 A1 a turbocharger for an internal combustion engine, wherein between a turbine wheel and a compressor wheel of the turbocharger, a centrifugal separator is provided, which is arranged in an intermediate chamber and coupled to a shaft, wherein the intermediate chamber has an opening for flowing in crankcase gases and at least one connection opening to the in Compressor having arranged compressor wheel.

From the German patent application DE 10 2007 054 922 A1 a separator for separating oil mist from the crankcase ventilation gas of an internal combustion engine having a gas cleaning space emerges, in which a rotatably mounted centrifugal rotor is arranged.

From the German patent application DE 10 2012 104 598 A1 For example, a separator for separating liquid droplets from an aerosol emerges, which has a rotor arranged in a housing with a plurality of mutually parallel disks.

The invention has for its object to provide an internal combustion engine and a method for operating an internal combustion engine, said disadvantages do not occur.

The object is achieved by providing the subject matters of the independent claims. Advantageous embodiments emerge from the subclaims.

The object is achieved in particular by providing an internal combustion engine which has at least one combustion chamber and a crankcase communicating with the at least one combustion chamber via a Beiblas path. There is one Venting path for venting the crankcase provided, which opens with a first end of two ends of the venting path in the crankcase, wherein in the venting path between the first and a second end of the two ends of a Ölabscheideeinrichtung is arranged. The internal combustion engine is characterized in that the oil separation device is designed as an actively driven device. By means of the actively driven oil separator, it is in particular possible to effect a high degree of separation and thus a thorough cleaning of the gases conveyed along the vent path, so that preferably no contamination or sooting of components downstream of the oil separator is to be feared, in particular downstream of the oil separator along the vent path Gases are promoted with high purity and in particular high oil-free.

The Ölabscheideeinrichtung has a controllable drive. In this case, the drive can be controlled in particular with respect to a rotational speed of the oil separation device. The internal combustion engine has a control device that is set up to control the controllable drive in dependence on a pressure in the crankcase. This makes it possible to influence the crankcase pressure by suitable control of the drive and in particular to ensure that it is always below a certain limit or within a certain range, in particular between a certain lower limit and a certain upper limit.

The fact that the crankcase communicates with the at least one combustion chamber via a Beiblaspfad means in particular that a connection between the combustion chamber and the crankcase is such that in a combustion cycle in the combustion chamber resulting combustion gases due to the increased pressure along a leakage path, namely the Beiblaspfads on Combustor seals, in particular piston seals, can flow past in the crankcase. Thus, while at least theoretically and according to a design target for the internal combustion engine, the combustion chamber and the crankcase are fluidly separated from each other, in practice it can not be completely avoided that combustion gases pass into the crankcase via the blow-by path.

The first end of the venting path and the second end of the venting path are in particular arranged opposite one another, viewed along a flow direction along the venting path.

Preferably, the internal combustion engine has a drainage path from the oil separation device into the crankcase, wherein oil deposited along the drainage path in the oil separation device is fed back into the crankcase. The crankcase is preferably - in particular directly - in fluid communication with an oil reservoir, in particular an oil pan, so that the oil drained along the drainage path into the crankcase can pass back into the oil reservoir.

In a preferred embodiment of the internal combustion engine, it is provided that the oil separation device is designed as a centrifugal separator, which separates oil droplets from a gas flow by centrifugal forces and the various densities of the media, in particular as a plate separator. Such a plate separator has, in particular, a plurality of turntables driven on a shaft driven in rotation about a rotation axis, in particular mutually parallel turntables, which have a surface on which the rotation axis is perpendicular. The rotational movement results in a radially outwardly directed flow on the surfaces of the turntable, wherein an oil separation is effected in particular by the centrifugal forces acting in the plate separator. A centrifugal separator, and in particular a plate separator, is particularly suitable for highly efficient cleaning of gases which have been conducted through it by entrained fluids, in particular by entrained oil.

An embodiment of the internal combustion engine is preferred, which is characterized in that the oil separation device is associated with an electric motor as a drive. The Ölabscheideeinrichtung is thus driven in particular by an electric motor. Preferably, the oil separation device is a separate electric motor as a separate drive, which is provided in particular exclusively for driving the Ölabscheideeinrichtung assigned. The Ölabscheideeinrichtung can be driven in a very efficient and easy to be realized by the electric motor.

Alternatively, it is possible that the Ölabscheideeinrichtung indirectly via the internal combustion engine itself, in particular via the crankshaft of the internal combustion engine, in particular by means of a suitable transmission or transmission mimic is driven. In this case, a separate drive for the oil separator can be saved. However, it then results in a dependence of the speed of the oil separator of the instantaneous speed of the internal combustion engine, wherein the drive of the oil separator via a separate drive allows a more flexible operation of the oil separator.

An embodiment of the internal combustion engine is preferred, which is characterized in that the second end of the two ends of the venting path opens into an environment of the internal combustion engine. This is an open venting system for the crankcase is realized. This is advantageous because even system-related no contamination or sooting of components of a charging path of the internal combustion engine is to be feared. In addition, the venting of the crankcase in an open system is completely independent of the degree of contamination of an air filter and / or of an intake pressure of a turbocharger. Due to the efficient, thorough separation of oil in the actively driven Ölabscheideeinrichtung it is readily possible to deliver the sufficiently purified gases directly into the environment of the internal combustion engine, in particular in the atmosphere.

The Ölabscheideeinrichtung is in particular designed as a conveyor. So it actively promotes gas from the crankcase along the vent path into the environment. In particular, when the Ölabscheideeinrichtung is designed as a centrifugal separator or Tellerseparator, this has a delivery function, in particular, acts as a fan, and thus causes an active venting of the crankcase along the venting path into an environment of the internal combustion engine.

If the second end of the discharge path discharges into an environment of the internal combustion engine, an additional oil entry into the combustion chamber via the charging path is completely avoided. This protects in particular optionally exhaust gas aftertreatment systems encompassed by the internal combustion engine.

Alternatively, however, an embodiment is possible in which the second end of the two ends of the venting path opens into a charging path of the internal combustion engine. In this case, too, due to the thorough and efficient cleaning of the gases in the actively driven Ölabscheideeinrichtung contamination or sooting of components of the charging path in any case to be feared less than is the case with a conventional oil separation. It is also possible in this embodiment that the actively driven Ölabscheideeinrichtung is also designed as a conveyor. However, this is not absolutely necessary, since a venting of the crankcase can also be driven by a pressure difference between the crankcase on the one hand and the charging path on the other hand.

Particularly preferably, the control device is set up to regulate the pressure in the crankcase by controlling the controllable drive. For this purpose, the internal combustion engine preferably has a pressure sensor in the crankcase, which is operatively connected to the control device, wherein it can detect a pressure in the crankcase and forward it to the control device. In the control device is preferably an upper limit and optionally additionally a lower limit, or a target value for the pressure in the crankcase deposited, it is also possible that, for example, depending on an operating point of the internal combustion engine or another suitable parameter, a plurality of Setpoints and / or limits are stored in a map. The control device is preferably operatively connected to the controllable drive in order to control it in such a way that the pressure in the crankcase is kept below the specified limit value or in a certain range or regulated to the at least one specific nominal value. Thus, the control device is in particular designed as a regulator for the pressure in the crankcase.

It is also preferred an embodiment of the internal combustion engine, which is characterized in that the venting path is free of an oil filter. Most preferably, the vent path is clear of any filter. In particular, then the oil separator is the only separation element for oil separation in the vent path. It can be seen that the actively driven oil separation device is preferably completely sufficient to effect a sufficient separation of oil from the gases conveyed along the ventilation path. It therefore requires no further filter, in particular no additional oil separator. Thus omitted otherwise scheduled maintenance and replacement parts, which makes the operation of the engine particularly cost and the system requires little maintenance.

The internal combustion engine is preferably designed as a reciprocating engine. In a preferred embodiment, the internal combustion engine is used to drive in particular heavy land or water vehicles, such as mine vehicles, trains, the internal combustion engine is used in a locomotive or a railcar, or ships. It is also possible to use the internal combustion engine to drive a defense vehicle, for example a tank. An exemplary embodiment of the internal combustion engine is preferably also stationary, for example, used for stationary power supply in emergency operation, continuous load operation or peak load operation, the internal combustion engine in this case preferably drives a generator. A stationary application of the internal combustion engine for driving auxiliary equipment, such as fire pumps on oil rigs, is possible. Furthermore, an application of the internal combustion engine in Area of promotion of fossil raw and especially fuels, for example, oil and / or gas, possible. It is also possible to use the internal combustion engine in the industrial sector or in the field of construction, for example in a construction or construction machine, for example in a crane or an excavator. The internal combustion engine is preferably designed as a diesel engine, as a gasoline engine, as a gas engine for operation with natural gas, biogas, special gas or another suitable gas. In particular, when the brake engine is designed as a gas engine, it is suitable for use in a cogeneration plant for stationary power generation.

The object is also achieved by providing a method for operating an internal combustion engine, wherein a crankcase of the internal combustion engine is vented via a venting path. In this case, an oil separation is carried out in the venting path by means of an actively driven oil separator. The Ölabscheideeinrichtung is used as a conveyor, wherein the crankcase is actively vented by the Ölabscheideeinrichtung. The ventilation of the crankcase is independent of a degree of contamination of an air filter and of a Ansaugunterdruck a turbocharger, because the venting directly through the conveyor, namely the Ölabscheideeinrichtung is specified. In this case, the Ölabscheideeinrichtung depends on a pressure in the crankcase - preferably with respect to their speed - driven. Thus, it is possible to keep the pressure in the crankcase by suitable control of the oil separator - in particular a suitable speed specification for these - always below at least one specific limit, within a certain range, or at least one specific setpoint. In connection with the method, the advantages that have already been explained in connection with the internal combustion engine.

Oil deposited in the separator is preferably drained from the oil separator into the crankcase. In this case, it may in particular pass from the crankcase, in turn, into an oil reservoir in fluid communication with the crankcase.

It is particularly preferred an embodiment of the method, which is characterized in that the pressure in the crankcase is controlled by controlling the Ölabscheideeinrichtung. In particular, a speed of the oil separator serves as a control variable for regulating the pressure in the crankcase. It is then possible to specify desired values for the crankcase pressure and to comply with these by the pressure regulation implemented in a simple manner. Thus, affected components of the internal combustion engine can be designed exactly.

An internal combustion engine control unit is also described, which is set up to carry out a method according to one of the previously described embodiments. In particular, the advantages that have already been described in connection with the internal combustion engine and the method are realized.

The control unit is preferably configured to detect a pressure in the crankcase and to control an actively driven oil separator as a function of the detected pressure. It is particularly preferably arranged to control the pressure in the crankcase, or alternatively or additionally, to maintain the pressure in the crankcase below at least a certain limit or within a certain range by driving the actively driven oil separator.

It is possible that the control unit is designed as a separate control unit for carrying out an embodiment of the method described here. However, the control unit is preferably designed as a central control unit of the internal combustion engine, in particular as an engine control unit (ECU).

It is possible for one embodiment of the method to be firmly implemented in an electronic structure, in particular a hardware structure, of the control device. Alternatively, it is possible that a computer program product is loaded into the control unit, which has instructions on the basis of which one of the previously described embodiments of the method can be carried out when the computer program product is running on the control unit.

In this respect, a computer program product is preferred, which has machine-readable instructions, on the basis of which one of the previously described embodiments of the method is feasible when the computer program product runs on a computing device, in particular a control unit of an internal combustion engine.

In this context, a data carrier is preferred which has such a computer program product.

The description of the internal combustion engine and the control unit on the one hand and the method on the other hand are to be understood as complementary to each other. Features of the internal combustion engine and / or the controller, which have been explained explicitly or implicitly in connection with the method, are preferably individually or combined with each other features of a preferred embodiment of the internal combustion engine and / or the control unit. Method steps which have been described explicitly or implicitly in connection with the internal combustion engine and / or the control unit are preferably individually or combined with one another Steps of a preferred embodiment of the method. This is preferably characterized by at least one method step, which is due to at least one feature of a preferred embodiment of the internal combustion engine and / or the control unit. The internal combustion engine and / or the control unit preferably draws / distinguishes itself by at least one feature, which is due to at least one step of a preferred embodiment of the method.

The invention will be explained in more detail below with reference to the drawing. The single figure shows a schematic representation of an embodiment of an internal combustion engine.

The only Fig. Shows an internal combustion engine 1 that has at least one combustion chamber 3 as well as a crankcase 5 having.

The internal combustion engine 1 is preferably designed as a reciprocating engine. It preferably has a plurality of combustion chambers 3 , in particular four cylinders, six cylinders, eight cylinders, ten cylinders, twelve cylinders, sixteen cylinders, eighteen cylinders, twenty cylinders or twenty-four cylinders, or a smaller, larger or different number of cylinders. It is possible that the internal combustion engine 1 as a series engine, as a V-engine, as a W-engine or with another suitable configuration of the combustion chambers 3 is trained.

At a combustion stroke in the combustion chamber 3 Combustion gases are produced under high pressure via a Beiblaspfad 7 - Especially on piston seals 9 over - into the crankcase 5 can reach. In this sense, communicates the crankcase 5 over the Beiblaspfad 7 with the combustion chamber 3 ,

For bleeding the crankcase 5 is a vent path 11 provided, the first end 13 and a second end 15 having. The first end 13 opens into the crankcase 5 , In the vent path 11 is between the first end 13 and the second end 15 an oil separator 17 arranged. This is here as actively driven oil separator 17 trained, giving a particularly thorough and safe cleaning of the venting path 11 ensured gases.

In the oil separator 17 separated oil is via a drainage path 19 back into the crankcase 5 directed. This stands with an oil reservoir 21 in fluid communication, via the drainage path 19 in the crankcase 5 returning oil to the oil reservoir 21 can flow.

The oil separator 17 is in the embodiment shown here as a plate separator 23 educated.

The oil separator 17 is a separate drive 25 assigned here as an electric motor 27 is trained. By means of the drive 25 becomes the oil separator 17 actively driven.

The second end 15 the venting path 11 flows into an environment here 29 the internal combustion engine 1 , The actively driven oil separator ensures this 17 adequate cleaning along the venting path 11 promoted gases, so this particular without further filtering or cleaning measures in the environment 29 can be dismissed. Thus, the venting system shown here is designed as an open system. This ensures in particular a complete independence of the system from a degree of contamination of an air filter of the internal combustion engine 1 and an intake negative pressure of a turbocharger thereof. Furthermore, there is no contamination or sooting of elements of a charging path of the internal combustion engine 1 to worry about when venting the crankcase 5 to the environment 29 to be led.

The oil separator 17 is also designed as a conveyor, wherein it actively gas along the vent path 11 in the nearby areas 29 promotes. In particular, as a Tellerseparator 23 trained oil separator 17 acts as a fan so far and generates a gas flow along the venting path 11 from the first end 13 to the second end 15 ,

The drive 25 the oil separator is preferably controlled, the internal combustion engine 1 a control device 31 which is set up to the controllable drive 25 depending on a pressure in the crankcase 5 head for.

For this purpose, the internal combustion engine 1 also a pressure sensor 33 which is adapted to the pressure in the crankcase 5 capture. The control device 31 is on the one hand with the pressure sensor 33 and on the other hand with the controllable drive 25 operatively connected so that the controllable drive 25 by means of the control device 31 depending on the pressure sensor 33 detected pressure in the crankcase 5 can be controlled.

In this case, the control device 31 Preferably set to the pressure in the crankcase 5 below a certain limit or within a certain range, or the pressure in the crankcase 5 to control to a specific setpoint. The control device 31 is therefore particularly preferably configured as a pressure regulator for the crankcase 5 ,

It is possible that the control device 31 is designed as a central engine control unit, or that the function of the control device 31 in the central engine control unit of the internal combustion engine 1 is integrated. Alternatively, it is possible that a separate control device as a control device 31 is provided.

It still shows that the venting path 11 Preferably, it is free of an oil filter, particularly preferably free of any filter element, so that it in particular as the only separating element, the actively driven separating device 17 having.

Overall, it turns out that especially the separately by the drive 25 driven oil separator 17 as an active system regardless of a speed of the internal combustion engine 1 can be operated. Furthermore, the Ölabscheideeinrichtung protects exhaust aftertreatment systems of the internal combustion engine 1 because of the crankcase breather no additional oil entry into the combustion chamber 3 takes place, especially at an open, to the environment 29 vented system. The system is low maintenance, in particular, no exchange of filters is necessary. Due to the open, to the environment 29 vented system creates no pollution or sooting of air-carrying parts, in particular along a charging path for the combustion chamber 3 , It may set or limit values for the crankcase pressure in the crankcase 5 can be specified, whereby affected components can thus be interpreted exactly. About the Beiblaspfad 7 in the crankcase 5 passing gases are sucked through the active separation system. Preferably, depending on the pressure in the crankcase 5 a speed and thus a suction intensity of the separator 17 by the control device 31 by controlling the drive 25 adjusted, whereby thresholds for the crankcase pressure can be maintained or a setpoint for the same can be adjusted. The separated oil is returned to the oil reservoir 21 passed, the purified gases are preferably to the atmosphere, in particular to the environment 29 the internal combustion engine 1 delivered.

Claims (7)

Internal combustion engine ( 1 ), with - at least one combustion chamber ( 3 ), and - one via a Beiblaspfad ( 7 ) with the at least one combustion chamber ( 3 ) communicating crankcase ( 5 ), wherein - the internal combustion engine ( 1 ) a venting path ( 11 ) for venting the crankcase ( 5 ) having a first end ( 13 ) of two ends ( 13 . 15 ) of the deaeration path ( 11 ) in the crankcase ( 5 ), wherein - in the venting path ( 11 ) between the first end ( 13 ) and a second end ( 15 ) of the two ends ( 13 . 15 ) an oil separator ( 17 ), wherein the oil separation device ( 17 ) is designed as an actively driven device, characterized in that - the oil separation device ( 17 ) a controllable drive ( 25 ), wherein the internal combustion engine ( 1 ) a control device ( 31 ) which is adapted to the controllable drive ( 25 ) depending on a pressure in the crankcase ( 5 ) head for. Internal combustion engine ( 1 ) according to claim 1, characterized in that the oil separation device ( 17 ) as a centrifugal separator, in particular Tellerseparator ( 23 ), is trained. Internal combustion engine ( 1 ) according to one of the preceding claims, characterized in that the oil separation device ( 17 ) is driven by an electric motor. Internal combustion engine ( 1 ) according to one of the preceding claims, characterized in that the second end ( 15 ) of the deaeration path ( 11 ) into an environment ( 29 ) of the internal combustion engine ( 1 ) opens. Internal combustion engine ( 1 ) according to one of the preceding claims, characterized in that the venting path ( 11 ) is free from an oil filter, preferably being free from any filter. Method for operating an internal combustion engine ( 1 ), wherein - a crankcase ( 5 ) of the internal combustion engine ( 1 ) via a venting path ( 11 ) is vented, wherein - an oil separation in the vent path ( 11 ) by means of an actively driven oil separator ( 17 ), where - the oil separator ( 17 ) is used as a conveyor, wherein the crankcase ( 5 ) actively by means of the oil separator ( 17 ) is vented, wherein - the oil separator ( 17 ) depending on a pressure in the crankcase ( 5 ) is driven. Method according to claim 6, characterized in that the pressure in the crankcase ( 5 ) by controlling the oil separator ( 17 ) is regulated.

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