DE202013102463U1 - Internal combustion engine with multi-flow turbine - Google Patents

Abstract

Internal combustion engine with at least one cylinder head with at least four cylinders (11, 12, 13, 14) arranged in line, in which - each cylinder (11, 12, 13, 14) has at least one outlet opening for discharging the exhaust gases from the cylinder (11, 12 , 13, 14) via the exhaust gas discharge system and an exhaust line (15a, 16a) connects to each outlet opening, - at least four cylinders (11, 12, 13, 14) are configured in such a way that they are two groups with at least two cylinders each (11, 12, 13, 14), - the first cylinder group comprises the two outer cylinders (11, 14) and the second cylinder group comprises the at least two inner cylinders (12, 13), the exhaust pipes (15a) of the two outer cylinders (11, 14) of the first cylinder group forming a first exhaust manifold (15) to form a first overall exhaust line (15A) and the exhaust lines (16a) of the at least two inner cylinders (12, 13) of the second cylinder group forming a it merge the second exhaust manifold (16) to a second total exhaust line (16A), and - the two total exhaust lines (15A, 16A) with a multi-flow turbine (1), the at least one mounted in a turbine housing (2) on a rotatable shaft (4) The impeller (3) are connected in such a way that a total exhaust gas line (15A, 16A) is connected to one of the at least two flows (8, 9) of the turbine (1), the at least two flows (8, 9) up to the at least one impeller (3) are separated from one another by means of the housing wall (5) and have different lengths and different volumes, characterized in that - the first overall exhaust line (15A) with a first flow (8), which is the smaller length and the Has smaller volume, is connected and the second total exhaust line (16A) with a second flow (9), which has the greater length and the greater volume, is connected.

Description

• – jeder Zylinder mindestens eine Auslassöffnung zum Abführen der Abgase aus dem Zylinder via Abgasabführsystem aufweist und sich an jede Auslassöffnung eine Abgasleitung anschließt,
• – mindestens vier Zylinder in der Art konfiguriert sind, dass sie zwei Gruppen mit jeweils mindestens zwei Zylindern bilden,
• – die erste Zylindergruppe die beiden außenliegenden Zylinder und die zweite Zylindergruppe die mindestens zwei innenliegenden Zylinder umfasst, wobei die Abgasleitungen der beiden außenliegenden Zylinder der ersten Zylindergruppe unter Ausbildung eines ersten Abgaskrümmers zu einer ersten Gesamtabgasleitung und die Abgasleitungen der mindestens zwei innenliegenden Zylinder der zweiten Zylindergruppe unter Ausbildung eines zweiten Abgaskrümmers zu einer zweiten Gesamtabgasleitung zusammenführen, und
• – die beiden Gesamtabgasleitungen mit einer mehrflutigen Turbine, die mindestens ein in einem Turbinengehäuse auf einer drehbaren Welle gelagertes Laufrad umfasst, in der Art verbunden sind, dass jeweils eine Gesamtabgasleitung mit einer der mindestens zwei Fluten der Turbine verbunden ist, wobei die mindestens zwei Fluten bis hin zum mindestens einen Laufrad mittels Gehäusewandung voneinander getrennt sind und unterschiedliche Längen und unterschiedliche Volumina aufweisen.

The invention relates to an internal combustion engine having at least one cylinder head with at least four cylinders arranged in series, in which

• Each cylinder has at least one outlet opening for discharging the exhaust gases out of the cylinder via the exhaust gas removal system and an exhaust gas line adjoins each outlet opening,
• At least four cylinders are configured in such a way that they form two groups each having at least two cylinders,
• The first cylinder group comprises the two outer cylinders and the second cylinder group comprises at least two inner cylinders, the exhaust pipes of the two outer cylinders of the first cylinder group forming a first exhaust manifold to a first exhaust line and the exhaust pipes of at least two inner cylinders of the second cylinder group Forming a second exhaust manifold merge to form a second total exhaust line, and
• - The two total exhaust gas lines with a Mehrflutigen turbine comprising at least one mounted in a turbine housing on a rotatable shaft impeller are connected in such a way that in each case an overall exhaust gas line is connected to one of the at least two floods of the turbine, wherein the at least two floods until towards the at least one impeller by means of housing wall are separated from each other and have different lengths and different volumes.

In the context of the present invention, the term internal combustion engine includes in particular gasoline engines, but also diesel engines and hybrid internal combustion engines, d. H. Internal combustion engines operated by a hybrid combustion process.

Internal combustion engines have a cylinder block and a cylinder head, which are connected together to form the at least four cylinders. The cylinder head is usually used to hold the valve train. In order to control the charge exchange, an internal combustion engine requires control devices - usually in the form of valves and actuators for actuating these control elements. The required for the movement of the valves valve actuating mechanism including the valves themselves is referred to as a valve train. As part of the charge exchange, the exhaust of the combustion gases via the outlet openings of the at least two cylinders and the filling of the combustion chambers, d. H. the intake of the fresh mixture or the charge air via the inlet openings.

The exhaust pipes, which connect to the outlet openings, are at least partially integrated in the cylinder head according to the prior art and are combined to form a common overall exhaust gas line or in groups to two or more total exhaust gas lines. Merging exhaust pipes to an overall exhaust line is referred to generally and in the context of the present invention as an exhaust manifold, and in the context of the present invention the total exhaust line is considered to belong to the exhaust manifold.

In which way the exhaust pipes of the at least four cylinders are brought together in the individual case, d. H. the concrete design of the exhaust system essentially depends on which operating range of the internal combustion engine takes priority, d. H. with regard to which operating ranges the operating behavior of the internal combustion engine is to be optimized.

In supercharged internal combustion engines in which at least one turbine of an exhaust gas turbocharger is provided in Abgasabführsystem and which should have a satisfactory performance at low speeds or smaller amounts of exhaust gas, a so-called shock charging is sought, d. H. prefers.

The purpose is to use the dynamic wave processes which take place in the exhaust gas removal system, in particular during the charge exchange, for the purpose of charging and for improving the operating behavior of the internal combustion engine.

The evacuation of the combustion gases from a cylinder of the internal combustion engine in the context of the charge exchange is based essentially on two different mechanisms. When, at the beginning of the charge cycle, the exhaust valve opens near bottom dead center, the combustion gases flow at high speed through the exhaust port into the exhaust system due to the high pressure level prevailing in the cylinder at the end of the combustion and the associated high pressure difference between the combustion chamber and the exhaust pipe. This pressure-driven flow process is accompanied by a high pressure peak, which is also referred to as Vorlassstoß and propagates along the exhaust pipe at the speed of sound, whereby the pressure degrades more or less with increasing distance due to friction, d. H. reduced.

In the course of the charge cycle, the pressures in the cylinder and in the exhaust line are equalized, so that the combustion gases are primarily not evacuated pressure driven, but due the lifting movement of the piston are pushed out.

At low speeds, the pre-discharge pulse can advantageously be used for boost charging, wherein short time, high pressure pulses are used as best as possible for energy use in the turbine. In this way, by turbocharging even with only small amounts of exhaust gas, especially at low speeds, high boost pressure conditions, d. H. high boost pressures are generated on the inlet side.

The bumping proves to be particularly advantageous in the acceleration of the turbine wheel, d. H. in increasing the turbine speed, which can drop noticeably in the idling mode of the engine or at low amounts of exhaust gas and often with increased load request by means of exhaust gas flow should be raised as quickly as possible again. The inertia of the impeller and the friction in the shaft bearing delay usually an acceleration of the impeller to higher speeds and thus an immediate increase in boost pressure.

To be able to use the running in the Abgasabführsystem dynamic wave processes, in particular the Vorlassstöße for the supercharging to improve the performance of the engine, the pressure peaks or Vorlassstöße must be obtained in Abgasabführsystem. It is therefore advantageous if the pressure pulses in the exhaust pipes do not weaken or cancel each other out.

In this regard, it is expedient to group the cylinders in such a way or to bring the exhaust pipes together in such a way that the high pressures, in particular the Vorlassstöße the individual cylinders are obtained in Abgasabführsystem and mutual interference can be largely avoided.

An internal combustion engine in which the cylinders are grouped is also an object of the present invention. According to the invention, the at least four cylinders arranged in series are configured in such a way that they form two groups each having at least two cylinders. The exhaust gas lines of the cylinders of each cylinder group lead together to form an exhaust gas manifold, forming an exhaust gas manifold. The cylinders are configured in such a way that the dynamic wave processes in the exhaust pipes of the cylinders of a group have the least adverse effect.

In a cylinder head with four cylinders arranged in series, it is advantageous in this regard, two cylinders, which have a firing interval of 360 ° KW, each to form a cylinder group together. If, for example, the ignition in the cylinders is initiated according to the ignition sequence 1-2-4-3 or according to the ignition sequence 1-3-4-2, it is advantageous for the outer cylinders to be a first group and the inner cylinders to be a second group to get together.

For the reasons stated above, the first cylinder group of the internal combustion engine according to the invention comprises the two outer cylinders and the second cylinder group comprises the at least two inner cylinders. Such a grouping or configuration of the Abgasabführsystems not only has advantages in terms of a possible shock charging, d. H. in terms of the improvement of the torque characteristic of the internal combustion engine at low speeds. Rather, there are further advantages, in particular with regard to a residual gas purging or regarding the reduction of the residual gas content in the cylinders.

It should be noted in this context that the pressure waves emanating from a cylinder, not only run through the at least one exhaust pipe of this cylinder, but also along the exhaust pipes of the other cylinder and possibly up to the provided at the end of the respective pipe outlet ,

Exhaust gas that has already been ejected or discharged into an exhaust gas line during the charge exchange can therefore again enter the cylinder as a result of the pressure wave that emanates from another cylinder.

It proves to be particularly disadvantageous if overpressure prevails at the outlet opening of a cylinder towards the end of the charge cycle, because in this phase of the charge cycle, the combustion gases are significantly ejected as a result of the stroke movement of the piston. Problems in the charge cycle arise especially at low speeds, if during a valve overlap, in which the exhaust valve is not closed when the inlet valve is open, exhaust gas should be flushed out at the expense of flushing losses as far as possible from the cylinder.

The problem concerning the reciprocal influence of the cylinders during the charge change is of increasing relevance, since the exhaust pipes or the exhaust manifolds in modern internal combustion engines are made shorter and shorter, in particular because the exhaust manifolds are increasingly being integrated into the cylinder head.

The short exhaust pipes can cause the cylinders of the internal combustion engine when changing the charge each other in disadvantageous Influence manner, in particular the effect achieved by an expiring Restgasausspülung is at least partially nullified.

For example, in a four-cylinder in-line engine in which all the exhaust pipes merge into one exhaust line and the cylinder thereof is operated with the firing order 1-3-4-2, the fourth cylinder may precede the third cylinder in the firing order, i.e., the third cylinder. H. even affect the previously ignited cylinder, during the charge exchange even in such a way that exhaust gas originating from the fourth cylinder enters the third cylinder before close the exhaust valves.

In order to counteract the problem described above, it is expedient to group the at least four cylinders as in the internal combustion engine according to the invention.

Before the pressure wave originating from one cylinder of the group reaches the exhaust port of another cylinder of this group, the exhaust valve has closed this exhaust port because the cylinders are grouped such that due to their thermodynamic offset, i. H. their ignition distance, a mutual influence is prevented when changing the charge.

The above statements make it clear that a grouping of the cylinder in the inventive manner in the structural design of an internal combustion engine is of increasing importance, both in connection with a possible shock charging and with respect to a most effective residual gas purging in the context of the charge cycle.

Against the background of the above, it is the object of the present invention to provide an internal combustion engine according to the preamble of claim 1, the Abgasabführsystem is optimized, in particular with regard to a shock charging and the most effective residual gas purging in the context of the charge cycle.

• – jeder Zylinder mindestens eine Auslassöffnung zum Abführen der Abgase aus dem Zylinder via Abgasabführsystem aufweist und sich an jede Auslassöffnung eine Abgasleitung anschließt,
• – mindestens vier Zylinder in der Art konfiguriert sind, dass sie zwei Gruppen mit jeweils mindestens zwei Zylindern bilden,
• – die erste Zylindergruppe die beiden außenliegenden Zylinder und die zweite Zylindergruppe die mindestens zwei innenliegenden Zylinder umfasst, wobei die Abgasleitungen der beiden außenliegenden Zylinder der ersten Zylindergruppe unter Ausbildung eines ersten Abgaskrümmers zu einer ersten Gesamtabgasleitung und die Abgasleitungen der mindestens zwei innenliegenden Zylinder der zweiten Zylindergruppe unter Ausbildung eines zweiten Abgaskrümmers zu einer zweiten Gesamtabgasleitung zusammenführen, und
• – die beiden Gesamtabgasleitungen mit einer mehrflutigen Turbine, die mindestens ein in einem Turbinengehäuse auf einer drehbaren Welle gelagertes Laufrad umfasst, in der Art verbunden sind, dass jeweils eine Gesamtabgasleitung mit einer der mindestens zwei Fluten der Turbine verbunden ist, wobei die mindestens zwei Fluten bis hin zum mindestens einen Laufrad mittels Gehäusewandung voneinander getrennt sind und unterschiedliche Längen und unterschiedliche Volumina aufweisen,

und die dadurch gekennzeichnet ist, dass

• – die erste Gesamtabgasleitung mit einer ersten Flut, welche die kleinere Länge und das kleinere Volumen aufweist, verbunden ist und die zweite Gesamtabgasleitung mit einer zweiten Flut, welche die größere Länge und das größere Volumen aufweist, verbunden ist.

This object is achieved by an internal combustion engine having at least one cylinder head with at least four cylinders arranged in series, in which

• Each cylinder has at least one outlet opening for discharging the exhaust gases out of the cylinder via the exhaust gas removal system and an exhaust gas line adjoins each outlet opening,
• At least four cylinders are configured in such a way that they form two groups each having at least two cylinders,
• The first cylinder group comprises the two outer cylinders and the second cylinder group comprises at least two inner cylinders, the exhaust pipes of the two outer cylinders of the first cylinder group forming a first exhaust manifold to a first exhaust line and the exhaust pipes of at least two inner cylinders of the second cylinder group Forming a second exhaust manifold merge to form a second total exhaust line, and
• - The two total exhaust gas lines with a Mehrflutigen turbine comprising at least one mounted in a turbine housing on a rotatable shaft impeller are connected in such a way that in each case an overall exhaust gas line is connected to one of the at least two floods of the turbine, wherein the at least two floods until towards the at least one impeller are separated by means of housing wall and have different lengths and different volumes,

and which is characterized in that

• The first overall exhaust gas line is connected to a first trough having the smaller length and the smaller volume, and the second total exhaust gas line is connected to a second trough having the greater length and the larger volume.

In the internal combustion engine according to the invention, the two total exhaust pipes with the at least two floods are not random, d. H. arbitrarily connected, but rather combined in a very specific way to optimize the bumping by means of multi-flow turbine. In this case, the internal combustion engine according to the invention makes use of the fact that both the at least two exhaust manifolds and the at least two turbine flows have different sized volumes and these volumes have an influence on the dynamic wave processes in the exhaust gas removal system and thus also on the bump charging or on the bump charging pressure pulses.

According to the invention, the first overall exhaust gas line belonging to the first exhaust manifold and thus to the large-volume exhaust manifold is connected to a first flow, which has the smaller length and the smaller volume, whereas the second exhaust gas line belonging to the second exhaust manifold and thus to the small-volume exhaust manifold has a second flow , which has the greater length and the larger volume connected.

This measure serves to determine the difference between the two volumes, which are upstream of the impeller in each case from the volume of a flood and the volume of the associated Compound exhaust manifold, reduce, ideally to eliminate.

It should be noted, namely, that different sized volumes of Abgababteilteilsysteme comprising a manifold and a flood lead to adverse effects regarding the performance of the internal combustion engine in shock charging.

Differently large volumes lead namely to differently sized pressure pulses at the end of the floods upstream of the impeller. However, a variation in the amplitude of the pressure pulses is unfavorable in terms of shock charging. On the contrary, it is desirable to have equally large pressure pulses at the end of the floods before they enter the impeller and thus volumes of the subsystems that are as equal as possible.

The distances, which must cover the pressure pulses in the respective Abgasabführteilsystemen from the outlet opening to the impeller are of different sizes, d. H. different lengths, which is why the time intervals between the impulse impulses arriving at the impeller are also different in size, d. H. vary.

The inventive, d. H. The targeted combination of the total exhaust gas lines with the floods also serves to reduce or eliminate the difference in the distances, so that the pressure pulses arrive regularly and with equal intervals at the impeller.

As explained in detail above, the internal combustion engine according to the invention advantageously characterized by the fact that the two Abgasabführteilsysteme the two cylinder groups that extend from the outlet openings of the respective cylinder to the impeller and each include a manifold and the associated flood, as little as possible differ in their exhaust gas volume and the pressure pulses have similar distances to bridge to the impeller.

An effective Restgasausspülung in the context of the charge change mitigates the knock problem in externally ignited internal combustion engines.

Thus, the object underlying the invention is achieved, namely provided an internal combustion engine according to the preamble of claim 1, the Abgasabführsystem is optimized, in particular with regard to a shock charging and the most effective residual gas purging in the context of the charge cycle.

In the internal combustion engine according to the invention, the exhaust gas lines of at least four cylinders are brought together to form two exhaust gas manifolds to two total exhaust gas lines. In this respect, embodiments with five or more cylinders, in which the exhaust pipes of more than four cylinders are combined to form two total exhaust pipes, are also internal combustion engines according to the invention.

Also, an internal combustion engine with, for example, six cylinders, in which the exhaust gas lines of the six cylinders are merged into three total exhaust pipes and these three total exhaust gas lines are connected to a three-flow turbine, is an internal combustion engine according to the invention.

Further advantageous embodiments of the internal combustion engine according to the invention are discussed in connection with the subclaims. In the following, it is assumed that a twin-flow turbine, if not specifically in the individual case subject of the description.

Embodiments of the internal combustion engine in which the first exhaust manifold has a larger volume than the second exhaust manifold are advantageous. The reasons are the ones already mentioned.

Advantageous embodiments of the internal combustion engine, in which the multi-flow turbine is a double-flow turbine, preferably a double-flow turbine, in which the two floods - seen in a section perpendicular to the axis of rotation of the at least one impeller - are arranged one above the other and the at least one impeller at least along an arcuate Spiral section on different sized radii enclose.

In double-flow turbines, the two floods are arranged radially differently spaced apart from each other to the shaft of the impeller, which is why the two floods of a double-flow turbine inevitably have different lengths and different volumes and the measure according to the invention when combining the total exhaust pipes with the floods particularly advantageous.

If a twin-flow turbine is used as the double-flow turbine, embodiments are advantageous in which each trough has an outlet opening at the impeller end which encloses the at least one impeller along an arcuate section of substantially 180 °.

Embodiments of the internal combustion engine may also be advantageous in which the multi-flow turbine is a twin-flow turbine, preferably a twin-flow turbine, in which the two floods the at least one impeller arranged side by side - at least along an arcuate portion spirally enclose on equal radii.

Advantageous embodiments of the internal combustion engine, in which the at least two floods of the turbine within the turbine housing by releasing at least one opening in the housing wall upstream of the impeller are connected to each other.

Bump charging also has disadvantages. It should be taken into account that a turbine is operated most effectively without intermittently and without alternating partial loading. In order to be able to optimally operate a turbine provided downstream of the cylinders in the exhaust-gas removal system at high engine speeds, the turbine should be subjected to an exhaust gas pressure that is as constant as possible in time, which is why a slightly changing pressure upstream of the turbine is preferred in order to realize a so-called congestion charging.

By a correspondingly large volume of exhaust gas upstream of the turbine, the pressure pulsations in the exhaust pipes can be smoothed. In this respect, the grouping of cylinders, in which the exhaust pipes are combined in groups and are separated from each other to the impeller, whereby the volume of Abgasabführsystems upstream of the turbine is divided into several sub-volumes proves to be counterproductive.

In the present embodiment of the internal combustion engine, the volume of the exhaust system communicating with a single trough of the turbine can be varied by connecting or disconnecting the tides of the turbine.

Consequently, the exhaust gas volume or the Abgasabführsystem upstream of the at least one impeller of Mehrflutigen turbine to different operating conditions of the internal combustion engine, in particular at different levels of exhaust gas quantities or speeds, adapted and optimized in this regard.

In principle, the at least two exhaust manifolds can be made connectable to each other. The connection of the at least two floods of the turbine, however, has the advantage that the connecting opening of the exhaust systems of the cylinder groups is arranged farther away from the outlet openings of the cylinders, whereby the exhaust gas line between a cylinder of one group and a cylinder of the other group is increased , The risk of mutual, in particular adverse influence on the change of charge is counteracted.

Embodiments of the internal combustion engine in which at least one displaceable wall piece is provided, which serves to release the at least one opening in the housing wall, are advantageous. The use of a wall piece opens the possibility to release a comparatively large opening in a simple manner just by moving this piece of wall.

Embodiments of the supercharged internal combustion engine may also be advantageous in which at least one shut-off element is provided in the housing wall, which serves to release the at least one opening in the housing wall. It can also be provided more openings and shut-off elements.

With the help of a shut-off element, the flow cross-section of the opening can be changed. In particular, the opening for the exhaust gas is released or closed, d. H. the two floods are connected or separated from each other. Embodiments in which the shut-off element is a valve, a slide, a flap or the like are advantageous.

Embodiments in which the shut-off element can be controlled electrically, hydraulically, pneumatically, mechanically or magnetically, preferably by means of the engine control of the internal combustion engine, are advantageous.

The shut-off element is preferably designed to be switchable in two stages in such a way that it either closes or releases the at least one opening, which simplifies the control and, in particular, offers cost advantages. However, the shut-off element may also be infinitely variable, for example, a sudden torque drop or increase in torque when the shut-off element is actuated, d. H. in the transition from bumping to congestion charging and vice versa, to avoid or to exploit in certain operating areas through intermediate positions resulting higher energy efficiency can.

Embodiments of the internal combustion engine in which the housing wall is an immovable wall fixedly connected to the housing are advantageous. This embodiment of the housing wall ensures that the heat introduced by the hot exhaust gas into the housing wall is dissipated in an advantageous manner and to a sufficient extent into and via the housing.

In internal combustion engines with four cylinders in series, embodiments are advantageous in which the first cylinder group, the two outer cylinders and the second Cylinder group includes the two inner cylinder.

Embodiments of the internal combustion engine in which the exhaust gas lines of the cylinders of each cylinder group within the cylinder head together to form two exhaust manifolds each lead to an overall exhaust gas line are advantageous.

The multi-flow turbine provided in the exhaust-gas removal system can then be located very close to the outlet of the internal combustion engine, i. H. be arranged close to the outlet openings of the cylinder. This has several advantages, especially because shorten the exhaust pipes between the cylinders and the turbine.

As the path to the turbine for the hot exhaust gases is shortened, the volume of the exhaust manifold or Abgasabführsystems decreases upstream of the turbine. The thermal inertia of the Abgasabführsystems also decreases by reducing the mass and the length of the involved exhaust pipes.

In this way, the exhaust enthalpy of the hot exhaust gases, which is largely determined by the exhaust pressure and the exhaust gas temperature, optimally utilized and a rapid response of the turbine can be ensured.

The proposed measure further leads to a compact design of the cylinder head and thus the internal combustion engine according to the invention and allows a dense packaging of the entire drive unit.

The shortening of the line lengths and the concomitant reduction of the exhaust volume upstream of the turbine supports the boost charge in the lower speed range.

Embodiments of the supercharged internal combustion engine in which the multi-flow turbine is the turbine of an exhaust-gas turbocharger are advantageous. An exhaust-gas turbocharger comprises a turbine arranged in the exhaust-gas removal system and a compressor arranged in the intake system.

The advantage of an exhaust gas turbocharger, for example in comparison to a mechanical supercharger, is that no mechanical connection is required for transmitting power between the supercharger and the internal combustion engine. While a mechanical supercharger obtains the energy required for its drive completely from the internal combustion engine and thus reduces the power provided and thus adversely affects the efficiency, the exhaust gas turbocharger uses the exhaust gas energy of the hot exhaust gases.

Preferably, a charge air cooling is provided, with which the compressed charge air is cooled before entering the cylinder. As a result, the density of the charge air supplied continues to increase. The cooling also contributes in this way to a compression and better filling of the combustion chambers, d. H. to an improved degree of filling, at. It may be advantageous to equip the intercooler with a bypass line in order to bypass the intercooler when necessary, for example, after a cold start.

The charge is a suitable means to increase the capacity of an internal combustion engine with unchanged displacement, or to reduce the displacement at the same power. In any case, the charging leads to an increase in space performance and a lower power mass. At the same vehicle boundary conditions, the load collective can thus be shifted to higher loads in which the specific fuel consumption is lower.

The torque characteristic of a supercharged internal combustion engine can be improved by providing a plurality of superchargers, exhaust-gas turbochargers and / or mechanical superchargers, arranged in parallel and / or in series in the exhaust-gas removal system.

Embodiments of the internal combustion engine in which at least one exhaust aftertreatment system is provided in the exhaust gas removal system are advantageous; For example, an oxidation catalyst, a three-way catalyst, a storage catalyst, a selective catalyst and / or a particulate filter.

When operating an internal combustion engine of the type described above, the at least two floods of the turbine are connected to each other in order to change from the supercharging to the jam charging. It is advantageous to connect the at least two floods of the turbine with each other when the speed of the internal combustion engine exceeds a first predetermined speed.

In the following the invention is based on an embodiment according to the 1 described in more detail. Hereby shows:

1 schematically a graphic assignment regulation of the two floods of a double-flow turbine to the two exhaust manifolds of a first embodiment of the internal combustion engine.

1 schematically shows a graphic assignment rule of the two floods 8th . 9 a double-flow turbine 1a to the two exhaust manifolds 15 . 16 a first embodiment of the internal combustion engine.

In the left half of the 1 is schematically the basic structure of a double-flow turbine 1a shown and cut perpendicular to the axis of rotation 4 of the impeller 3 ,

The illustrated double-flow turbine 1a is an example of a twin-flow turbine 1 ie for a turbine 1 with two floods 8th . 9 , The turbine 1 has a turbine housing 2 in which an impeller 3 on a rotatable shaft 4 is stored.

The double-flow turbine 1a is characterized in that the two floods 8th . 9 are arranged one above the other and the impeller 3 at least along an arcuate portion spirally enclose on different radii. The two inlet openings 6 . 7 the double-flow turbine 1a are in a flange 10 of the housing 2 arranged, being attached to each inlet 6 . 7 a flood 8th . 9 the turbine 1 followed. The two floods 8th . 9 are radially different distances to the shaft 4 the turbine 1 spaced and are right up to the impeller 3 by means of housing wall 5 separated from each other. In this way, the exhaust gas flows of the two floods 8th . 9 separated from each other on the impeller 3 directed.

In the right half of the 1 is schematically illustrated the basic structure of the Abgasabführsystems the associated four-cylinder internal combustion engine.

The two outer cylinders 11 . 14 form a first cylinder group whose exhaust pipes 15a under formation of a first exhaust manifold 15 to a first total exhaust line 15A to merge. The two inner cylinders 12 . 13 form a second cylinder group whose exhaust pipes 16a under formation of a second exhaust manifold 16 to a second total exhaust line 16A to merge.

In each case one total exhaust gas line 15A . 16A will be with one of the two floods 8th . 9 the turbine 1 connected. The first total exhaust gas line 15A and thus the large-volume first manifold 15 comes with the first tide 8th , which has the smaller length and the smaller volume connected, whereas the second total exhaust line 16A and thus the small-volume second manifold 16 with the second tide 9 , which has the greater length and the larger volume is connected.

In this way it is ensured that the two Abgasabführteilsysteme comprising a respective manifold 15 . 16 and a flood 8th . 9 upstream of the impeller 3 have a similar volume or the difference in the volumes is as low as possible.

LIST OF REFERENCE NUMBERS

1

twin-flow turbine

1a

Double-flow turbine

2

turbine housing

3

Wheel

4

Rotation axis, shaft

5

housing

6

first entrance opening

7

second inlet

8th

first tide

9

second tide

10

flange

11

first cylinder

12

second cylinder

13

third cylinder

14

fourth cylinder

15

first exhaust manifold of the first cylinder group

15a

Exhaust pipe of a cylinder of the first cylinder group

15A

first total exhaust gas line

16

second exhaust manifold of the second cylinder group

16a

Exhaust pipe of a cylinder of the second cylinder group

16A

second total exhaust line

Claims (12)

Internal combustion engine with at least one cylinder head with at least four cylinders arranged in series ( 11 . 12 . 13 . 14 ), in which - each cylinder ( 11 . 12 . 13 . 14 ) at least one outlet opening for discharging the exhaust gases from the cylinder ( 11 . 12 . 13 . 14 ) via Abgasabführsystem and to each outlet opening an exhaust pipe ( 15a . 16a ), - at least four cylinders ( 11 . 12 . 13 . 14 ) are configured in such a way that they have two groups each having at least two cylinders ( 11 . 12 . 13 . 14 ), - the first cylinder group the two outer cylinders ( 11 . 14 ) and the second cylinder group the at least two inner cylinders ( 12 . 13 ), wherein the exhaust pipes ( 15a ) of the two outer cylinders ( 11 . 14 ) of the first cylinder group to form a first exhaust manifold ( 15 ) to a first overall exhaust gas line ( 15A ) and the exhaust pipes ( 16a ) of the at least two inner cylinders ( 12 . 13 ) of the second cylinder group to form a second exhaust manifold ( 16 ) to a second total exhaust line ( 16A ), and - the two total exhaust gas lines ( 15A . 16A ) with a multi-flow turbine ( 1 ), which at least one in a turbine housing ( 2 ) on a rotatable Wave ( 4 ) stored impeller ( 3 ), are connected in the way that in each case a total exhaust gas line ( 15A . 16A ) with one of the at least two floods ( 8th . 9 ) of the turbine ( 1 ), the at least two floods ( 8th . 9 ) to at least one impeller ( 3 ) by means of housing wall ( 5 ) are separated from one another and have different lengths and different volumes, characterized in that - the first overall exhaust gas line ( 15A ) with a first flood ( 8th ), which has the smaller length and the smaller volume, and the second total exhaust gas line ( 16A ) with a second flood ( 9 ), which has the greater length and the larger volume, is connected. Internal combustion engine according to claim 1, characterized in that the first exhaust manifold ( 15 ) has a larger volume than the second exhaust manifold ( 16 ). Internal combustion engine according to claim 1 or 2, characterized in that the multi-flow turbine ( 1 ) a double-flow turbine ( 1a ). Internal combustion engine according to claim 3, characterized in that the multi-flow turbine ( 1 ) a double-flow turbine ( 1a ), where the two floods ( 8th . 9 ) - in a section perpendicular to the axis of rotation ( 4 ) of the at least one impeller ( 3 ) - are arranged one above the other and the at least one impeller ( 3 ) at least along an arcuate portion helically enclose on different sized radii. Internal combustion engine according to claim 3 or 4, characterized in that each flood ( 8th . 9 ) has at the impeller-side end an outlet opening, the at least one impeller ( 3 ) encloses along an arcuate portion of substantially 180 °. Internal combustion engine according to claim 1 or 2, characterized in that the multi-flow turbine ( 1 ) is a twin-flow turbine. Internal combustion engine according to claim 6, characterized in that the multi-flow turbine ( 1 ) is a twin-flow turbine, in which the two floods ( 8th . 9 ) the at least one impeller ( 3 ) - arranged side by side - at least along an arcuate portion spirally enclose on equal radii. Internal combustion engine according to one of the preceding claims, characterized in that two floods ( 8th . 9 ) of the turbine ( 1 ) within the turbine housing ( 2 ) by releasing at least one opening in the housing wall ( 5 ) upstream of the impeller ( 3 ) are connectable to each other. Internal combustion engine according to one of the preceding claims, characterized in that the housing wall ( 5 ) an immovable and fixed to the housing ( 2 ) connected wall. Internal combustion engine according to one of the preceding claims with four cylinders arranged in series ( 11 . 12 . 13 . 14 ), characterized in that the first cylinder group the two outer cylinder ( 11 . 14 ) and the second cylinder group the two inner cylinders ( 12 . 13 ). Internal combustion engine according to one of the preceding claims, characterized in that the exhaust pipes ( 15a . 16a ) the cylinder ( 11 . 12 . 13 . 14 ) each cylinder group within the cylinder head to form two exhaust manifolds ( 15 . 16 ) in each case to an overall exhaust gas line ( 15A . 16A ) merge. Internal combustion engine according to one of the preceding claims, characterized in that the multi-flow turbine ( 1 ) the turbine ( 1 ) is an exhaust gas turbocharger.

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