DE102019202380B4 - Internal combustion engine with an exhaust manifold and an exhaust gas turbocharger - Google Patents

Abstract

Internal combustion engine (1) with an exhaust manifold (4) and an exhaust gas turbocharger (3), the exhaust manifold (4) being fluidically connected to the exhaust gas turbocharger (3 ) is connected, with the bypass line (9) branching off from the exhaust manifold (4) via an inlet opening and opening into an exhaust gas outlet (17) of the exhaust gas turbocharger (3) via an exhaust gas outlet opening (20), and with an actuating element in the bypass line (9). (11) a control valve (10) for setting different flow cross-sectional areas of the bypass line (9) is arranged fluidically closer to the inlet opening than to the exhaust gas outlet opening (20), characterized in that the exhaust gas outlet opening (20) is composed of several partial exhaust gas outlet openings (21), which are arranged annularly in a housing (5) of the exhaust gas turbocharger (3), and that at one The exhaust gas outlet cross section (18) of the exhaust gas outlet (17) is fluidically connected to an exhaust gas inlet cross section of a vehicle catalytic converter, which is directly attached to the housing (5) of the exhaust gas turbocharger (3), with a maximum flow cross section of the vehicle catalytic converter in the exhaust gas flow direction having a larger diameter than the exhaust gas outlet cross section (18 ).

Description

The invention relates to an internal combustion engine with an exhaust manifold and an exhaust gas turbocharger, the exhaust manifold being fluidically connected to the exhaust gas turbocharger via a main line upstream of an exhaust gas turbine of the exhaust gas turbocharger and via a bypass line downstream of the exhaust gas turbine, the bypass line branching off from the exhaust gas manifold via an inlet opening and via a Exhaust gas outlet opening opens into an exhaust gas outlet of the exhaust gas turbocharger, and wherein in the bypass line an actuating element of a control valve for setting different flow cross-sectional areas of the bypass line is arranged fluidically closer to the inlet opening than to the exhaust gas outlet opening.

From the prior art, for example, the publication DE 10 2004 001 371 A1 known. This describes an internal combustion engine with exhaust gas recirculation, the internal combustion engine having an intake line with an intake compressor on the input side and an exhaust gas line belonging to the exhaust gas recirculation, which is connected to the intake line by a junction. An additional compressor is provided in series with the intake compressor and upstream of the confluence, the function of which can be reversed for expander operation. Also from the prior art is the document US 8,499,557 B2 known.

Furthermore, the reference discloses U.S. 2015/0 361 873 A1 a turbocharger with a turbine housing and a conduit. An exhaust gas inlet area of the turbine housing is connected to an exhaust system element and has a turbine wheel connection and a bypass connection. The duct is configured to cover an inner peripheral surface of the exhaust gas inlet portion in a state where at least a part of the duct is spaced apart from the inner peripheral surface. The duct has an inserted portion located in the exhaust gas inlet portion of the turbine housing.

Furthermore, the pamphlet shows DE 10 2006 001 571 A1 a charging device for internal combustion engines with at least one turbine part. An exhaust gas mass flow flows to this via an inflow region, from which a bypass channel branches off to bypass the at least one turbine part. The bypass duct opens into a turbine outlet duct at an orifice behind the turbine part. The bypass duct is opened or closed either by a first control element arranged in the inflow area at the inlet of the by-pass duct or by a second control element at the outlet of the by-pass duct into the turbine outlet duct. Other turbochargers are the publications U.S. 3,089,304A and DE 10 2012 200 562 A1 refer to.

The object of the invention is to propose an internal combustion engine which has advantages over known internal combustion engines, in particular a better connection of the exhaust gas turbocharger to the exhaust manifold in terms of flow technology, preferably with a smaller space requirement.

According to the invention, this is achieved with an internal combustion engine having the features of claim 1 . It is provided that the exhaust gas outlet opening is made up of several partial exhaust gas outlet openings, which are arranged in a ring shape in a housing of the exhaust gas turbocharger, and that an exhaust gas inlet cross section of a vehicle catalytic converter is fluidically connected to an exhaust gas outlet cross section of the exhaust gas outlet, which is attached directly to the housing of the exhaust gas turbocharger, with a in the exhaust gas flow direction, the maximum flow cross section of the vehicle catalytic converter has a larger diameter than the exhaust gas outlet cross section.

The internal combustion engine is part of a motor vehicle, for example, and in this case is preferably used to drive the motor vehicle, that is to say to provide a drive torque aimed at driving the motor vehicle. The internal combustion engine has a motor housing which has, for example, a cylinder crankcase and a cylinder head, the cylinder crankcase and the cylinder head together delimiting at least one cylinder of the internal combustion engine together with a piston arranged displaceably in the cylinder crankcase. At least one inlet valve and at least one outlet valve for the cylinder are arranged in the cylinder head. If the internal combustion engine has a plurality of cylinders, then each of the cylinders is assigned at least one such intake valve and at least one such exhaust valve.

A fresh gas channel can be fluidically connected to the cylinder via the inlet valve and an exhaust gas channel can be connected via the outlet valve. This means that the flow connection is interrupted in a first switching position of the respective valve and established in a second switching position. The exhaust duct is connected to the cylinder or the exhaust valve on the one hand and to the exhaust manifold on the other. The exhaust manifold is used to discharge the exhaust gas of the internal combustion engine and - if the combustion engine having multiple cylinders - combining the exhaust gas of the multiple cylinders. If there are several cylinders, each of the cylinders is fluidically connected to the exhaust manifold via an outlet valve and an exhaust gas channel. The exhaust gas from the several cylinders is brought together in the exhaust manifold and only then discharged together from the internal combustion engine.

Furthermore, the internal combustion engine has the exhaust gas turbocharger, which is used to increase the rated output of the internal combustion engine and/or to increase the efficiency of the internal combustion engine. The exhaust gas turbocharger has an exhaust gas turbine and a compressor. Exhaust gas from the internal combustion engine can be supplied to the exhaust gas turbine. Flow energy and/or enthalpy contained in the exhaust gas can be converted into kinetic energy by means of the exhaust gas turbine, which in turn is used to drive the compressor. Fresh gas is compressed with the help of the compressor and then the compressed fresh gas is fed to the internal combustion engine, namely via the fresh gas channel and the inlet valve.

The exhaust gas turbocharger has the housing in which at least the exhaust gas turbine, but preferably also the compressor, is arranged. In order to achieve a compact configuration of the internal combustion engine, it can be provided that the exhaust gas turbocharger rests directly on the engine housing, in particular on the cylinder head, and is fastened to it. The exhaust manifold can be designed to be integrated in the cylinder head. This means that the exhaust gas occurring in the cylinders is brought together inside the cylinder head. Only the merged exhaust gas is then fed out of the cylinder head. The cylinder head preferably has an exhaust gas outlet opening accordingly. The exhaust manifold is now connected on the one hand to the exhaust gas duct or the exhaust gas ducts and on the other hand to the exhaust gas outlet opening, the exhaust gas outlet opening representing an exhaust gas connection of the cylinder head or forming one with it. Alternatively, of course, it can also be provided that the exhaust manifold is arranged outside of the cylinder head.

It has already been explained that the exhaust gas turbocharger has the exhaust gas turbine, which is fluidically connected to the exhaust manifold, for example via the exhaust gas connection of the cylinder head. The main line is provided for this purpose, which on the one hand branches off from the exhaust manifold and on the other hand is fluidically connected to the exhaust gas turbine of the exhaust gas turbocharger. The main line is connected to the exhaust gas turbine in such a way that the exhaust gas supplied to the exhaust gas turbocharger through the main line flows through or over a turbine wheel of the exhaust gas turbine. For this purpose, the main line is connected to the exhaust gas turbocharger upstream of the turbine wheel, viewed in the flow direction of the exhaust gas.

Depending on an operating point of the internal combustion engine, it can be advantageous not to feed the exhaust gas generated by the internal combustion engine to the exhaust gas turbine, but rather around it. The bypass line is provided for this purpose. This opens into an exhaust gas outlet coming from the exhaust gas turbine downstream of the turbine wheel or the exhaust gas turbine, as viewed in the direction of flow of the exhaust gas. The bypass line has the inlet opening on the one hand and the exhaust gas outlet opening on the other. The bypass line opens into the exhaust manifold via the inlet opening or branches off from it. On the other hand, via the exhaust gas outlet opening, the bypass line opens into the exhaust gas outlet of the exhaust gas turbocharger, namely downstream of the turbine wheel.

The control element of the control valve is arranged in the bypass line. The control valve is used to set different flow cross-sectional areas of the bypass line. The control valve can therefore be used to set what proportion of the exhaust gas generated by the internal combustion engine flows through the exhaust gas turbine or is routed around the exhaust gas turbine or the turbine wheel through the bypass line.

Different throughflow cross-sectional areas can be set with the aid of the control valve, at least a first throughflow cross-sectional area and a second throughflow cross-sectional area. The two flow cross-sectional areas are different from one another. For example, the first through-flow cross-sectional area is equal to zero, whereas the second through-flow cross-sectional area corresponds to a maximum through-flow cross-sectional area of the bypass line.

If the first flow cross-sectional area is set, the bypass line is completely blocked, so that the exhaust gas generated by the internal combustion engine is routed completely through the exhaust gas turbine. When the second throughflow cross-sectional area is set, however, the bypass line is completely released, so that at least part of the exhaust gas, preferably a large part of the exhaust gas or even all of the exhaust gas, is routed around the exhaust gas turbine through the bypass line.

To set the different flow cross-sectional areas, the control valve has the control element, which can be arranged in different switch positions, with the first flow cross-sectional area being set when the control element is in a first switch position, and the second flow cross-sectional area of the bypass line being set when a second switch position is present.

Usually, the control element sits directly on the exhaust gas outlet opening of the bypass line. However, this has the consequence that on the one hand the exhaust gas outlet of the exhaust gas turbocharger must be made sufficiently large to accommodate the actuating element. On the other hand, due to the actuating element, turbulence occurs in the exhaust gas outlet, which leads to undesired flow losses. For this reason, the actuating element should now be shifted away from the exhaust gas outlet opening and for this purpose should be arranged fluidically closer to the inlet opening than to the exhaust gas outlet opening.

For this purpose, the distance between the inlet opening and the control valve along the bypass line corresponds to a total flow length of the bypass line from the inlet opening to the exhaust gas outlet opening at most 50%, at most 40%, at most 30%, at most 25%, at most 20%, at most 15 % or at most 10%. However, even smaller distances between the inlet opening and the actuating element of less than 10%, for example of at most 5%, are preferred.

By arranging the actuating element outside of the exhaust gas outlet in the bypass line, a flow cross section of the exhaust gas outlet can be reduced, so that the exhaust gas turbocharger requires less installation space.

In order to additionally prevent the exhaust gas entering the exhaust gas outlet through the exhaust gas outlet opening of the bypass line from causing undesired turbulence and thus flow losses, the exhaust gas outlet opening is composed of several partial exhaust gas outlet openings. This means that the exhaust gas outlet opening not only has a single connected flow cross section, but rather a plurality of flow cross sections that are separate from one another and are arranged at a distance from one another. The partial exhaust gas outlet openings, which make up the exhaust gas outlet opening, are arranged and formed in a ring shape in the housing of the exhaust gas turbocharger. This means that the partial exhaust gas outlet openings are arranged in a circle, ie along an imaginary circle. The imaginary circle preferably encloses a circular area which is perpendicular to an axis of rotation of a turbine wheel of the exhaust gas turbine. In addition, the partial exhaust gas outlet openings are preferably at the same distance from the axis of rotation.

The embodiment of the internal combustion engine described has an advantageous embodiment of the exhaust gas turbocharger, which is characterized on the one hand by a small space requirement and on the other hand avoids unwanted turbulence, so that a high level of efficiency is provided.

A preferred embodiment of the invention provides that the partial exhaust gas outlet openings encompass an axis of rotation of a turbine wheel of the exhaust gas turbine in the circumferential direction by at least 180°, at least 270°, at least 300°, at least 330° or at least 245°. The partial exhaust gas outlet openings that are spaced furthest from one another in the circumferential direction enclose at least one of the stated angles in the circumferential direction. This achieves a particularly uniform distribution of the exhaust gas exiting from the bypass line into the exhaust gas outlet, so that the flow losses are particularly significantly reduced.

A development of the invention provides that the partial exhaust gas outlet openings open into the exhaust gas outlet via an annular gap formed in the housing. In this respect, the partial exhaust gas outlet openings do not open directly into the exhaust gas outlet, but initially only into the annular gap, which in turn opens into the exhaust gas outlet. To this extent, the annular gap fluidically connects the exhaust gas outlet partial openings to the exhaust gas outlet. The annular gap is fluidically connected on the one hand directly to the partial exhaust gas outlet openings and on the other hand directly to the exhaust gas outlet. The annular gap is formed in the housing of the exhaust gas turbocharger. The annular gap brings about a homogenization of the exhaust gas exiting into it through the partial exhaust gas outlet openings, so that the exhaust gas enters the exhaust gas outlet from the annular gap and is distributed particularly uniformly in the circumferential direction. Accordingly, a further reduction in flow losses is achieved.

A particularly preferred embodiment of the invention provides that the annular gap surrounds the axis of rotation of the turbine wheel in the circumferential direction by at least 180°, at least 270°, at least 300°, at least 330°, at least 345° or completely. The annular gap has a continuous extension in the circumferential direction by at least one of the angles mentioned. Provision can be made for the annular gap to cover the axis of rotation only partially in the circumferential direction encompasses, ie extends in the circumferential direction from a beginning to an end different from the beginning. Particularly preferably, however, the annular gap completely encompasses the axis of rotation in the circumferential direction. This brings about a particularly effective homogenization of the exhaust gas exiting from the partial exhaust gas outlet openings.

A preferred further embodiment of the invention provides that the bypass line has a plurality of partial bypass lines, with at least one of the partial exhaust gas outlet openings being fluidically connected to the inlet opening via each of the partial bypass lines. To this extent, the bypass line is divided downstream of the inlet opening into the plurality of partial bypass lines, which run parallel to one another in terms of flow. Each of the partial bypass lines is fluidically connected to the inlet opening on the one hand and to at least one of the partial exhaust gas outlet openings on the other hand. A plurality of partial exhaust gas outlet openings are preferably connected to each of the partial bypass lines, in particular the same number of partial exhaust gas outlet openings to each of the partial bypass lines. This achieves a particularly uniform distribution of the exhaust gas over the circumference.

In a further embodiment of the invention, it can be provided that the partial exhaust gas outlet openings and/or the annular gap are at a distance from the axis of rotation of the turbine wheel in the radial direction that is greater by a factor of at most 2, at most 1.75 or at most 1.5 as a radius of an outer circumference of the turbine wheel. Ultimately, this means that the imaginary ring or the imaginary circle along which the several partial exhaust gas outlet openings are arranged has a diameter that is larger by at most one of the factors mentioned than the diameter of the turbine wheel. As a result, the particularly compact design of the exhaust gas turbocharger is realized. The radius or the diameter of the outer circumference of the turbine wheel is to be understood as meaning the largest radius or the largest diameter of the turbine wheel.

The invention provides that an exhaust gas inlet cross section of a vehicle catalytic converter is fluidically connected to an exhaust gas outlet cross section of the exhaust gas outlet, said exhaust gas inlet cross section being attached directly to the housing of the exhaust gas turbocharger. In this respect, the vehicle catalytic converter acts directly on the housing of the exhaust gas turbocharger and is fastened to it, for example by means of a band clamp, in particular a V-band clamp. For this purpose, the exhaust gas turbocharger preferably has an outlet flange and the vehicle catalytic converter has an inlet flange, which lie against one another and are fastened to one another. The exhaust gas outlet cross section is in the outlet flange and the exhaust gas inlet cross section is in the inlet flange. After the vehicle catalytic converter has been arranged on the exhaust gas turbocharger, the exhaust gas outlet cross section and the exhaust gas inlet cross section are preferably directly adjacent to one another, in particular they are arranged parallel to one another. The direct arrangement of the vehicle catalytic converter on the exhaust gas turbocharger results in a particularly compact configuration of the internal combustion engine.

According to the invention, it is provided that a maximum flow cross section of the vehicle catalytic converter in the exhaust gas flow direction has a larger diameter than the exhaust gas outlet cross section. The maximum flow cross-section of the vehicle catalytic converter is to be understood as meaning that flow cross-section which, in the flow direction through the vehicle catalytic converter, has the largest flow cross-sectional area which is occupied by the exhaust gas. For example, the maximum flow cross section is directly in front of or directly behind a filter body of the vehicle catalytic converter. The maximum flow cross section should now be larger or have a larger diameter than the exhaust gas outlet cross section. This means that the flow cross section widens downstream of the exhaust gas outlet cross section, ie no longer in the exhaust gas turbocharger, but only in the vehicle catalytic converter. This achieves a compact configuration of the exhaust gas turbocharger.

A further embodiment of the invention provides that the exhaust manifold is integrated into the cylinder head. This has already been pointed out above. By dispensing with a separate exhaust manifold outside of the cylinder head, the installation space required by the internal combustion engine is in turn reduced.

Finally, within the scope of a further preferred embodiment of the invention it can be provided that the bypass line runs at least in regions through the cylinder head and the actuating element is arranged in a region of the bypass line running through the cylinder head. In order to avoid pressure losses in the exhaust gas as far as possible, the bypass line should run through the cylinder head at least in certain areas. The control valve or at least its control element should also be present in the cylinder head. Such a configuration of the bypass line enables a comparatively large flow cross section, so that unnecessary flow losses or unnecessary throttling are avoided becomes. Overall, the at least partial arrangement of the bypass line in the cylinder head offers the advantage of a comparatively large flow cross section, so that the exhaust gas can flow through the bypass line with only small flow losses when the flow cross section area is adjusted accordingly.

A further embodiment of the invention provides that the actuating element is a poppet valve element. The control valve is designed as a poppet valve, so that the control element is accordingly present as a poppet valve element. The poppet valve or the poppet valve element enables the constant setting of different flow cross-sections and also permanently ensures high tightness because the poppet valve element can be repositioned in the direction of a valve seat for the poppet valve element at any time. Of course, a configuration of the adjusting element that differs from the poppet valve can also be implemented.

A further preferred embodiment of the invention provides that the adjusting element interacts with a valve seat formed by the cylinder head for setting the different flow cross sections. The control valve has the control element and the valve seat as relevant elements. The adjusting element interacts with the valve seat to set the different flow cross-sectional areas. In the case of the poppet valve element, for example, the different flow cross-sectional areas are present at different distances from the poppet valve element to the valve seat. The valve seat is formed by the cylinder head or at least it is attached directly to the cylinder head. For example, the valve seat is made of the same material as the cylinder head. Alternatively, the valve seat can also be present as an insert element, which is manufactured separately from the cylinder head and subsequently inserted into it. In any case, however, the valve seat is in the cylinder head.

A further development of the invention provides that the exhaust manifold has a first exhaust gas outlet opening and a second exhaust gas outlet opening, the first exhaust gas outlet opening being fluidically connected to the exhaust gas turbocharger upstream of the exhaust gas turbine and the second exhaust gas outlet opening being downstream of the exhaust gas turbine. Both exhaust gas outlet openings are on the side of the exhaust manifold facing away from the cylinder or cylinders. In this respect, the entire exhaust gas of the internal combustion engine exits through the exhaust gas outlet openings, in particular the combined exhaust gas of a number of cylinders of the internal combustion engine.

Both exhaust gas outlet openings are designed on or in the exhaust manifold, so that the exhaust manifold is fully integrated in the cylinder head. The first outlet opening is fluidically connected to the exhaust gas turbocharger upstream of the exhaust gas turbine and the second exhaust gas outlet opening is downstream of the exhaust gas turbine. To this extent, the exhaust gas exiting from the exhaust manifold through the first exhaust gas outlet opening flows through the exhaust gas turbine, while the exhaust gas exiting through the second exhaust gas outlet opening is routed around the exhaust gas turbine.

On the one hand, such a configuration has the already mentioned advantage of the complete integration of the exhaust manifold into the cylinder head, and on the other hand, the flow connection between the exhaust manifold and the exhaust gas turbocharger can be established in a simple manner, namely by arranging the exhaust gas turbocharger on the cylinder head. The flow cross-sectional area of the first exhaust gas outlet opening is preferably larger than the flow cross-sectional area of the second exhaust gas outlet opening. For example, the flow cross-sectional area of the second exhaust gas outlet opening is at most 75%, at most 50% or at most 25% of the flow cross-sectional area of the first exhaust gas outlet opening.

A further embodiment of the invention provides that the first exhaust gas outlet opening and the second exhaust gas outlet opening reach through a contact surface of the cylinder head, against which the housing of the exhaust gas turbocharger lies flat. The contact surface of the cylinder head serves to support the housing of the exhaust gas turbocharger. When the exhaust gas turbocharger is installed on the cylinder head, the housing is placed against the contact surface and the exhaust gas turbocharger is attached to the cylinder head. The two exhaust gas outlet openings, i.e. the first exhaust gas outlet opening and the second exhaust gas outlet opening, now reach through the contact surface, so that after the exhaust gas turbocharger has been attached to the cylinder head, the flow connection between the two exhaust gas outlet openings and the exhaust gas turbocharger is established.

The contact surface in which the two exhaust gas outlet openings are present is completely and continuously flat. The planar configuration of the contact surface means that the contact surface lies entirely in an imaginary plane. The housing of the exhaust gas turbocharger has a corresponding mating contact surface, which is preferably also flat. However, it can be provided that there is at least one seal on or in the contact surface and/or the counter contact surface. For example, the housing of the exhaust gas turbocharger is attached to the cylinder via a flat gasket derkopf, whereby the flat seal rests flat on the one hand on the contact surface and on the other hand on the counter contact surface. The exhaust gas outlet openings are preferably each arranged at a distance from an edge of the planar contact surface, ie they are not directly adjacent to the edge.

To establish the flow connection between the two exhaust gas outlet openings and the exhaust gas turbocharger, the exhaust gas turbocharger or its housing preferably has exhaust gas inlet openings which correspond to the exhaust gas outlet openings, in particular are aligned with them. A first exhaust gas inlet opening of the exhaust gas turbocharger is assigned to the first exhaust gas outlet opening and a second exhaust gas inlet opening is assigned to the second exhaust gas outlet opening. The first exhaust gas inlet port is upstream of the exhaust gas turbine and the second exhaust gas inlet port is downstream of the exhaust gas turbine.

Each of the exhaust gas inlet openings is preferably aligned with the corresponding exhaust gas outlet opening. For this purpose, the first exhaust gas inlet opening has the same dimensions as the first exhaust gas outlet opening and the second exhaust gas inlet opening has the same dimensions as the second exhaust gas outlet opening. In addition, after the exhaust gas turbocharger has been arranged on the cylinder head, the first exhaust gas inlet opening completely overlaps the first exhaust gas outlet opening and the second exhaust gas inlet opening completely overlaps the second exhaust gas outlet opening. Such a fluidic connection of the exhaust gas turbocharger to the exhaust manifold results in a particularly low flow resistance and therefore a low pressure loss.

A preferred further embodiment of the invention provides that the bypass line in the cylinder head branches off from an exhaust gas line of the exhaust manifold, the first exhaust gas outlet opening being connected directly to the exhaust gas line and the second exhaust gas outlet opening being connected to the exhaust gas line via the control valve and the bypass line. The exhaust gas of the internal combustion engine, in particular the combined exhaust gas of the plurality of cylinders, is discharged in the direction of the exhaust gas turbocharger via the exhaust pipe of the exhaust manifold. The bypass line branches off from this exhaust line. The first exhaust gas outlet opening is connected directly to the exhaust gas line, whereas the second exhaust gas outlet opening is connected to the exhaust gas line via the control valve and the bypass line. Correspondingly, a very low flow resistance is realized across the exhaust manifold up to the first exhaust gas outlet opening.

As part of a further embodiment of the invention, it can be provided that the adjusting element for setting the different flow cross sections can be displaced in a displacement direction which is preferably perpendicular to a longitudinal center axis of the exhaust pipe. The bypass line opens into the exhaust gas line at a certain angle, preferably perpendicularly with respect to the longitudinal central axis. For example, the angle is at most 90°, at most 75°, at most 60° or at most 45°. Of course, other angles can also be realized. More preferably, the longitudinal center axis of the exhaust gas line runs through the center point of the first exhaust gas outlet opening, so that the exhaust gas is guided through the exhaust gas line without deflection up to the first exhaust gas outlet opening. The exhaust gas flowing out of the exhaust line into the bypass line, on the other hand, is deflected, so that a certain pressure loss occurs here. However, this is not relevant due to the bypassing of the exhaust gas turbine.

• 1 eine schematische Darstellung eines Bereichs einer Brennkraftmaschine, nämlich eines Zylinderkopfs,
• 2 eine schematische Teilschnittdarstellung der Brennkraftmaschine, sowie
• 3 eine schematische Schnittdarstellung durch einen Abgasturbolader der Brennkraftmaschine.

The invention is explained in more detail below with reference to the exemplary embodiments illustrated in the drawing, without the invention being restricted. It shows:

• 1 a schematic representation of an area of an internal combustion engine, namely a cylinder head,
• 2 a schematic partial sectional view of the internal combustion engine, and
• 3 a schematic sectional view through an exhaust gas turbocharger of the internal combustion engine.

the 1 shows a schematic representation of an internal combustion engine 1, more precisely a part of the internal combustion engine 1, of which a cylinder head 2 and a merely indicated exhaust gas turbocharger 3 can be seen. The exhaust gas turbocharger 3 is fluidically connected to an exhaust manifold 4 which is integrated into the cylinder head 2 . The exhaust gas turbocharger 3 has a housing 5, which is only indicated here, which rests against the cylinder head 2 and is fastened to it. The exhaust gas turbocharger 3 has an exhaust gas turbine, by means of which flow energy and/or enthalpy of exhaust gas can be converted into mechanical energy, with which in turn a compressor of the exhaust gas turbocharger 3 can be driven.

The exhaust manifold 4 has a first exhaust gas outlet opening 6 and a second exhaust gas outlet opening 7 , both of which are formed in and on the cylinder head 2 . Both exhaust gas outlet openings 6 and 7 are connected to the exhaust gas turbocharger 3 . Exhaust gas exiting from the first exhaust gas outlet opening 6 becomes the Exhaust gas turbine of the exhaust gas turbocharger 3 is supplied, whereas exhaust gas exiting from the second exhaust gas outlet opening 7 flows into an exhaust pipe downstream of the exhaust gas turbine and is discharged in the direction of an external environment.

The first exhaust gas outlet opening 6 is connected directly to an exhaust pipe 8 of the exhaust manifold 4 . The second exhaust gas outlet opening 7 is connected to the exhaust gas line 8 via a bypass line 9 and a control valve 10, of which a control element 11 can be seen here. It can be seen that both the exhaust gas line 8 and the bypass line 9 run through the cylinder head 2 up to the respective exhaust gas outlet opening 6 or 7 . The control valve 10 , in particular its control element 11 , is also located in the cylinder head 2 . This enables a dethrottling of an exhaust line of the internal combustion engine 1 because the bypass line 9 in the cylinder head 2 can be designed with a comparatively large flow cross section.

the 2 shows a schematic partial sectional representation of the internal combustion engine 1. It can be seen that in addition to the actuating element 11, a valve seat 12 of the actuating valve 10 is also arranged in the cylinder head 2. For example, the valve seat 12 is in the form of a ring insert, which is inserted into a corresponding receptacle in the cylinder head 2 . The control valve 10 is designed as a poppet valve, so that the control element 11 is correspondingly in the form of a poppet valve element.

The control valve 10 is used to set different flow cross-sectional areas of the bypass line 9. In the first switching position of the control valve 10 indicated here, the flow cross-sectional area is equal to zero, the bypass line 9 is therefore completely closed. The bypass line 9, in particular the valve seat 12, can be surrounded by a cooling channel 13 at least in certain areas. This enables the control valve 10, in particular the control element 11 and the valve seat 12, to be cooled so that a long service life can be ensured.

It is clear that the first exhaust gas outlet opening 6 and the second exhaust gas outlet opening 7 are formed in a contact surface 14 or pass through it. The exhaust gas outlet openings 6 and 7 are both formed in the contact surface 14 with closed edges. The contact surface 14 is preferably flat, so it lies completely in an imaginary plane. The contact surface 14 serves as a support surface for the exhaust gas turbocharger 3 or its housing 5. The exhaust manifold 4 correspondingly has a counter contact surface with which it bears against the contact surface 14 after it has been mounted on the cylinder head 2.

the 3 shows a longitudinal sectional view through the exhaust gas turbocharger 3, namely with respect to an axis of rotation 15 of a turbine wheel 16 of the exhaust gas turbine of the exhaust gas turbocharger 3. Downstream of the turbine wheel 16, an exhaust gas outlet 17 with an exhaust gas outlet cross section 18 is formed in the housing 5 of the exhaust gas turbocharger 3. The exhaust gas coming from the exhaust manifold 4 flows through or overflows at least temporarily and at least partially the turbine wheel 16 and then reaches the exhaust gas outlet 17. It then exits through the exhaust gas outlet cross section 18 from the exhaust gas turbocharger 3, in particular in the direction of a vehicle catalytic converter, not shown here. To connect the vehicle catalytic converter to the exhaust gas turbocharger 3 , the housing 5 has an outlet flange 19 which surrounds the exhaust gas outlet cross section 18 . The exhaust gas outlet cross section 18 preferably has a diameter which is smaller than the diameter of a maximum flow cross section of the vehicle catalytic converter.

The bypass line 9 branches off from the exhaust manifold 4 at an inlet opening. It opens into the exhaust gas outlet 17 at its opposite end via an exhaust gas outlet opening 20 . The exhaust gas outlet opening 20 is made up of several partial exhaust gas outlet openings 21 which are arranged in a ring in the housing 5 of the exhaust gas turbocharger 3 . In the exemplary embodiment shown here, four partial exhaust gas outlet openings 21 are formed, which are distributed uniformly over the circumference. The partial exhaust gas outlet openings 21 open into an annular gap 22 , which is also formed in the housing 5 , preferably continuously in the circumferential direction with respect to the axis of rotation 15 . On the one hand, the annular gap 22 is fluidically connected to the partial exhaust gas outlet opening 21 and, on the other hand, to the exhaust gas outlet 17 . The exhaust gas emerging from the partial exhaust gas outlet openings 21 therefore flows through the annular gap 22 into the exhaust gas outlet 17 .

It can be seen that the partial exhaust gas outlet openings 21 are at a distance in the radial direction from the axis of rotation of the turbine wheel 16 which is only slightly larger than a radius of the turbine wheel 16, in particular the largest radius of the turbine wheel 16. For example, the distance between the partial exhaust gas outlet openings 21 is The axis of rotation 15 is at most twice as large as the radius of the turbine wheel 16. This results in an extremely compact design of the housing 5 and at the same time a lower pressure loss when the exhaust gas flows in.

The configuration of the internal combustion engine 1 described here enables, on the one hand, comparatively large flow cross sections of the bypass line 9 and, on the other hand, a simple and rapid establishment of the flow connection between the exhaust manifold 4 and the exhaust gas turbocharger 3. Both are achieved by the at least partial integration of the bypass line 9 and the actuating element 11 in realized the cylinder head 2. In addition, the use of the partial exhaust gas outlet openings 21 and the (optional) annular gap 22 achieves a low flow resistance because turbulence when the exhaust gas flows from the bypass line 9 into the exhaust gas outlet 17 is largely or even completely avoided.

Reference List

1

internal combustion engine

2

cylinder head

3

exhaust gas turbocharger

4

exhaust manifold

5

Housing

6

exhaust outlet opening

7

exhaust outlet opening

8th

exhaust pipe

9

bypass line

10

control valve

11

actuator

12

valve seat

13

cooling channel

14

contact surface

15

axis of rotation

16

turbine wheel

17

exhaust outlet

18

exhaust outlet cross-section

19

outlet flange

20

exhaust outlet opening

21

Exhaust outlet part opening

22

annular gap

Claims (8)

Internal combustion engine (1) with an exhaust manifold (4) and an exhaust gas turbocharger (3), the exhaust manifold (4) being fluidically connected to the exhaust gas turbocharger (3 ) is connected, with the bypass line (9) branching off from the exhaust manifold (4) via an inlet opening and opening into an exhaust gas outlet (17) of the exhaust gas turbocharger (3) via an exhaust gas outlet opening (20), and with an actuating element in the bypass line (9). (11) of a control valve (10) for setting different flow cross-sectional areas of the bypass line (9) is arranged fluidically closer to the inlet opening than to the exhaust gas outlet opening (20), characterized in that the exhaust gas outlet opening (20) is composed of several partial exhaust gas outlet openings (21), which are arranged annularly in a housing (5) of the exhaust gas turbocharger (3), and that at one The exhaust gas outlet cross section (18) of the exhaust gas outlet (17) is fluidically connected to an exhaust gas inlet cross section of a vehicle catalytic converter, which is directly attached to the housing (5) of the exhaust gas turbocharger (3), with a maximum flow cross section of the vehicle catalytic converter in the exhaust gas flow direction having a larger diameter than the exhaust gas outlet cross section (18 ). internal combustion engine claim 1 , characterized in that the partial exhaust gas outlet openings (21) surround an axis of rotation (15) of a turbine wheel (16) of the exhaust gas turbine in the circumferential direction by at least 180°, at least 270°, at least 300°, at least 330° or at least 345°. Internal combustion engine according to one of the preceding claims, characterized in that the partial exhaust gas outlet openings (21) open into the exhaust gas outlet (17) via an annular gap (22) formed in the housing (5). internal combustion engine claim 3 , characterized in that the annular gap (22) surrounds an axis of rotation (15) of a turbine wheel (16) in the circumferential direction by at least 180°, at least 270°, at least 300°, at least 230°, at least 345° or completely. Internal combustion engine according to one of the preceding claims, characterized in that the bypass line (9) has a plurality of partial bypass lines, at least one of the partial exhaust gas outlet openings (21) being fluidically connected to the inlet opening via each of the partial bypass lines. internal combustion engine claim 3 , characterized in that the partial exhaust gas outlet openings (21) and/or the annular gap (22) are at a distance from an axis of rotation (15) of a turbine wheel (16) in the radial direction by a factor of at most 2, at most 1.75 or at most 1.5 is greater than a radius of an outer circumference of the turbine wheel (16). Internal combustion engine according to one of the preceding claims, characterized in that the exhaust manifold (4) is integrated into a cylinder head (2). internal combustion engine claim 7 , characterized in that the bypass line (9) runs at least partially through the cylinder head (2) and the adjusting element (11) is arranged in a through the cylinder head (2) running region of the bypass line (9).

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