Turbine for an exhaust gas turbocharger, in particular an internal combustion engine, exhaust gas turbocharger and motor vehicle

Abstract

The invention relates to a turbine (1) for an exhaust gas turbocharger, with a turbine wheel driven by exhaust gas, with a bypass channel (3) having an opening (5) through which at least a portion of the exhaust gas can be introduced into the bypass channel (3), via which the turbine wheel can be bypassed by the exhaust gas introduced into the bypass channel (3) and flowing through the bypass channel (3), with a component (2) through which the exhaust gas can flow and which has the opening (5), which also has a valve seat (6), wherein the inlet opening (5) is completely surrounded by the valve seat (6) along its circumferential direction (8), and with a valve element (9) which can be moved relative to the component (2) between a closed position (S) fluidically blocking the opening (5) and thereby the bypass channel (3), in which closed position the valve element (9) sits on the valve seat (6),and at least one open position which at least partially releases the opening (5) and thereby the bypass channel (3).

Description

[0001] The invention relates to a turbine for an exhaust gas turbocharger, in particular of an internal combustion engine, according to the preamble of claim 1. Furthermore, the invention relates to an exhaust gas turbocharger with such a turbine. The invention also relates to a motor vehicle.

[0002] CN 109072770 B discloses a turbine for an exhaust gas turbocharger. DE 10 2013 002 894 B4 discloses a turbine for an exhaust gas turbocharger. US 9 322 327 B2 discloses a single-stage turbocharger. Furthermore, a turbocharger is known from JP 6098314 B2.

[0003] The object of the present invention is to provide a turbine for an exhaust gas turbocharger, in particular an internal combustion engine, an exhaust gas turbocharger and a motor vehicle, so that a particularly advantageous operation of the turbine can be realized.

[0004] This object is achieved according to the invention by a turbine having the features of patent claim 1, by an exhaust gas turbocharger having the features of patent claim 9, and by a motor vehicle having the features of patent claim 10. Advantageous embodiments of the invention are the subject of the dependent claims.

[0005] A first aspect of the invention relates to a turbine for an exhaust gas turbocharger, also simply referred to as a turbo or turbocharger, in particular of an internal combustion engine. This means that the internal combustion engine, also referred to as an internal combustion engine, motor, or internal combustion engine and preferably designed as a reciprocating piston engine, i.e., a reciprocating piston motor, has the exhaust gas turbocharger and thus the turbine in its fully manufactured state, since the exhaust gas turbocharger has the turbine in its fully manufactured state. The internal combustion engine has an exhaust tract through which exhaust gas from at least one combustion chamber, in particular from several combustion chambers, of the internal combustion engine can flow, and in which the turbine is arranged.Furthermore, the internal combustion engine has, for example, an intake tract through which fresh air can flow, by means of which the fresh air flowing through the intake tract can be guided to and into the respective combustion chamber. The aforementioned compressor is, for example, located in the intake tract. For example, the compressor has a compressor wheel, by means of which the fresh air can be compressed.

[0006] The turbine has a turbine wheel driven by the exhaust gas. The compressor wheel can be driven by the turbine wheel, in particular via a shaft of the exhaust gas turbocharger, whereby the fresh air can be compressed by the compressor wheel by driving the compressor wheel. For example, the turbine wheel is arranged in a turbine housing of the turbine, through which the exhaust gas can flow.

[0007] The turbine has a bypass duct having an opening. The opening is a flow-through opening because the exhaust gas can flow through it. The opening can be an inlet opening through which at least a portion of the exhaust gas can be introduced into the bypass duct. Alternatively, the opening is an outlet opening through which exhaust gas introduced into the bypass duct can be discharged, i.e., led out, from the bypass duct. For example, the bypass duct runs in the turbine housing, i.e., within the turbine housing, in particular such that the bypass duct is delimited, in particular directly, by an inner circumferential surface of the turbine housing.

[0008] In particular, the bypass duct has, for example, in particular precisely two openings, namely the inlet opening, through which at least a portion of the exhaust gas can be introduced into the bypass duct, and the outlet opening, through which the exhaust gas introduced into the bypass duct can be discharged from the bypass duct, i.e. can be discharged. The inlet opening and the outlet opening are collectively referred to as flow openings. The opening is one of the flow openings. The exhaust gas introduced into the bypass duct, in particular via the inlet opening, can subsequently flow through the bypass duct. The bypass duct is also referred to as a wastegate or wastegate duct. The turbine wheel can be bypassed by the exhaust gas introduced into the bypass duct and flowing through the bypass duct via the bypass duct.This means that the exhaust gas introduced into the bypass duct and subsequently flowing through the bypass duct bypasses the turbine wheel, so that the exhaust gas flowing through the bypass duct does not flow onto the turbine wheel and therefore does not drive it. For this purpose, for example, the bypass duct itself, i.e. considered on its own, is fluidly connected at a first connection point and a second connection point to an exhaust branch of the exhaust tract through which the exhaust gas flows, wherein, for example, the turbine and thus the turbine wheel are arranged in the exhaust branch. In the flow direction of the exhaust gas flowing through the exhaust tract and thus the exhaust branch, the first connection point is arranged upstream of the turbine wheel, and in the flow direction of the exhaust gas flowing through the exhaust tract and thus the exhaust branch, the second connection point is arranged downstream of the turbine wheel.For example, the inlet opening is arranged at the first connection point and the outlet opening at the second connection point. By means of the bypass duct, at least the aforementioned portion of the exhaust gas can be branched off from the exhaust branch at the first connection point and, in particular, introduced into the bypass duct via the inlet opening. The exhaust gas branched off from the exhaust branch at the first connection point and, in particular, introduced into the bypass duct via the inlet opening can be guided from the first connection point to the second connection point by means of the bypass duct and, in particular, introduced back into the exhaust branch at the second connection point, in particular via the outlet opening.The exhaust gas branched off at the first connection point by means of the bypass duct and introduced into the bypass duct via the inlet opening bypasses the turbine wheel on its way from the first connection point to the second connection point, thus not driving the turbine wheel on its way from the first connection point to the second connection point. For example, by adjusting a quantity, i.e. in particular a volume and / or mass flow, of the exhaust gas flowing through the bypass duct, a turbine output, also referred to as turbine power, can be adjusted, i.e., varied. This allows, for example, a boost pressure to which the fresh air can be compressed by the compressor to be adjusted, i.e., varied.

[0009] The turbine has a component through which the exhaust gas can flow and which has the opening. For example, the component also has the bypass channel, so that, for example, the bypass channel runs in the component, i.e., inside the component. The component is, for example, the turbine housing or a component of the turbine housing. For example, the component is designed as a single piece, i.e., formed from a single piece. In other words, the component is preferably designed as a one-piece body, i.e., formed from a single piece and thus manufactured integrally and thus formed as a monoblock. The previous and following statements regarding the component can easily be applied to the turbine housing and vice versa. For example, the component is produced by casting, i.e., by means of a casting process, so that the component is preferably designed as a cast component.

[0010] The component also has a valve seat. In other words, the component also forms the aforementioned valve seat. The opening is completely surrounded by the valve seat along its circumferential direction, i.e., completely circumferentially. This means that the valve seat extends 360 degrees around the opening in the circumferential direction. In particular, the term "valve seat" refers to a surface, particularly a flat one, which is also referred to as a seat surface or valve seat surface or valve face. The valve seat is formed by the component.

[0011] The opening is continuous along a passage direction, in particular a straight one, and the exhaust gas can therefore flow through it, so that the passage direction coincides with a flow direction along or into which the exhaust gas can flow through the opening, so that the exhaust gas can be introduced into the bypass channel via the opening along or in the flow direction or can be discharged from the bypass channel. This means that during operation of the turbine, with the exhaust gas flowing through the opening and thus the bypass channel during operation, the exhaust gas flows through the opening along or in the flow direction and thus flows into the bypass channel via the opening or flows out of the bypass channel along or in the flow direction. In particular, it can be provided that the opening runs in one plane.In other words, the opening extends, for example, in a plane, with the passage direction and thus the flow direction running perpendicular to the aforementioned plane. The valve seat, for example, extends in the aforementioned plane. In particular, the opening is completely circumferential in the circumferential direction of the opening and is preferably directly delimited by the component, in particular by a border or edge of the component.

[0012] The turbine also has a valve element, which is also referred to as a bypass valve or wastegate valve. The valve element is movable relative to the component between a closed position fluidically blocking the opening and at least one open position, also referred to as the first open position. When reference is made above and below to the open position, this means, unless otherwise stated, the at least one open position, thus the first open position. Very preferably, the closed position and the open position are respective end positions of the valve element, which, in particular in the fully manufactured state of the turbine, can be moved relative to the turbine housing into the respective end position, but not beyond the respective end position.In particular, for example, the valve element can be moved relative to the component into the closed position and into the open position, and preferably the valve element can be held, i.e., fixed, in the closed position and in the open position relative to the component, so that, for example, relative movements between the valve element and the component are prevented in the closed position and in the open position. Thus, for example, the aforementioned amount of exhaust gas flowing through the bypass channel can be adjusted by means of the valve element.

[0013] In the closed position, the valve element sits, in particular directly, on the valve seat. This means in particular that in the closed position the valve element touches the valve seat, in particular directly. In particular, it is provided that in the closed position the valve element sits on the entire valve seat, in particular directly. Thus, in the closed position, the opening and thus the bypass channel are fluidically blocked by the valve element, so that when the valve element is in the closed position, no exhaust gas can flow through the opening. Thus, in the closed position, no exhaust gas can be introduced from the exhaust branch into the bypass channel, so that when the valve element is in the closed position, no exhaust gas is branched off from the exhaust branch via the inlet opening and the bypass channel, or in the closed position, no exhaust gas can flow out of the bypass channel via the outlet opening.Thus, in the closed position, the flow of exhaust gas through the bypass channel is prevented. For example, in the closed position of the valve element, the amount of exhaust gas flowing through the bypass channel is zero, i.e., set to zero, except for any unavoidable leaks.

[0014] In the open position, the valve element at least partially opens the opening and thus the bypass channel, so that in the open position of the valve element at least the said portion of the exhaust gas can be branched off from the exhaust branch and introduced into the bypass channel via the inlet opening and subsequently flow through the bypass channel or so that exhaust gas introduced into the bypass channel is discharged from the bypass channel. Thus, in the open position at least the said portion of the exhaust gas bypasses the turbine wheel via the bypass channel. Thus, the aforementioned quantity of exhaust gas flowing through the bypass channel is greater than zero in the open position of the valve element. In the open position, at least a partial region of the valve element, the partial region of which sits, in particular directly, on the valve seat in the closed position, is spaced from the valve seat.In other words, in the open position the valve element is at least partially lifted off the valve seat. Expressed again in other words, in the open position of the valve element at least the partial area of ​​the valve element is lifted off the valve seat, so that in the open position of the valve element at least the partial area of ​​the valve element is not sitting on the valve seat. In the closed position of the valve element, however, the partial area of ​​the valve element sits, in particular directly, on the valve seat. In particular, it is provided that in the open position of the valve element the entire valve element is spaced from the, in particular the entire, valve seat, so that preferably in the open position of the valve element the entire valve element is lifted off the, in particular the entire, valve seat.Thus, in the open position of the valve element, at least the said part of the exhaust gas from the exhaust branch can flow between the partial area of ​​the valve element and the valve seat and thus flow through the opening and thus flow into the bypass channel via the opening or flow out of the bypass channel.

[0015] In order to be able to realize particularly advantageous operation of the turbine and thus of the exhaust gas turbocharger as a whole, it is provided according to the invention that the component has a projection which adjoins the valve seat, in particular directly, and which projects from the valve seat. In particular, it is provided that the projection projects from the valve seat along or in a projecting direction, wherein the projecting direction preferably runs obliquely parallel to the direction of flow through the opening. In this case, it is particularly conceivable that, particularly when considering the opening alone, the projecting direction corresponds to the flow direction in which the exhaust gas flows through the opening during the aforementioned operation of the turbine, so that the projecting direction and the flow direction point in the same direction.In particular, it is conceivable that the protrusion direction and the opening direction, in which the valve element can be moved from the closed position into or toward the intermediate position, are identical, thus pointing in the same direction. For example, if the opening is the inlet opening, the valve element is opened into the bypass channel, so to speak. If, for example, the opening is the outlet opening, the valve element is opened away from the bypass channel, so to speak.

[0016] The projection extends in the circumferential direction of the opening at least or only, that is to say exclusively partially, circumferentially around the opening. This means that the projection extends in the circumferential direction of the opening over 360 degrees and thus completely around the opening, or over less than 360 degrees and thus only partially around the opening. The circumferential direction of the opening runs around the flow direction of the exhaust gas flowing through the opening, wherein the circumferential direction of the opening runs, for example, in the aforementioned plane in which the opening extends. Furthermore, it is provided according to the invention that the valve element is at least or only partially surrounded by the projection in the circumferential direction of the opening, both in the closed position and in an intermediate position of the valve element lying between the closed position and the open position, which intermediate position of the valve element at least partially opens the opening and thus the bypass channel.In other words, the valve element is movable, for example, along a movement path between the open position and the closed position relative to the component. The open position and the closed position are components of the movement path, such that the open position and the closed position lie on the movement path. In particular, the closed position and the open position are or form respective ends of the movement path, in particular when the closed position and the open position are the aforementioned end positions of the valve element. The intermediate position lies on the movement path and thus between the open position and the closed position. It is conceivable that the intermediate position lies on the movement path and thus closer to the closed position than to the open position. Since the valve element releases the opening and thus the bypass channel in the intermediate position, the intermediate position is a second open position of the valve element.In this case, it is particularly conceivable for the valve element to open the opening and thus the bypass channel more strongly, i.e. further, than in the intermediate position. Thus, for example, in the open position, a first value for the quantity of exhaust gas flowing through the opening and the bypass channel is set, and in the intermediate position, for example, a second value for the quantity of exhaust gas flowing through the opening and thus the bypass channel is set, wherein the first value and the second value are each greater than zero, and wherein the second value is less than the first value. In the closed position, for example, a third value for the quantity of exhaust gas flowing through the opening and thus the bypass channel is set, wherein the third value is preferably zero and thus less than the first value and less than the second value.For example, the valve element can be moved into the intermediate position and held in the intermediate position relative to the component, i.e. be or become fixed, so that, for example, in the intermediate position, relative movements between the component and the valve element are prevented. This allows the aforementioned values ​​for the quantity of exhaust gas flowing through the opening and thus the bypass channel to be adjusted as required. In the intermediate position and in the closed position, the projection surrounds the valve element at least or only partially in the circumferential direction of the opening, so that, for example, both in the closed position and in the intermediate position, the valve element is at least partially overlapped by the projection along an overlap direction running perpendicular to the flow direction of the exhaust gas flowing through the opening.Thus, for example, in the intermediate position of the valve element, at least a portion of the exhaust gas flowing through the exhaust branch can flow between the projection and the valve element and thus be branched off from the exhaust branch and introduced into the bypass channel via the opening or discharged from the bypass channel.

[0017] In the open position of the valve element, the valve element, in particular the entire valve element, is arranged, in particular completely, without overlapping with the projection. This means that in the open position of the valve element, the projection does not surround the valve element in the circumferential direction of the opening, so that in the open position the valve element, in particular the entire valve element, is not overlapped by the projection, i.e. is not arranged in overlap with the projection, in particular viewed completely circumferentially in the circumferential direction of the opening and thus of the valve element. For example, in the intermediate position, the smallest flow cross section through which the exhaust gas from the exhaust branch can flow is delimited by the valve element and by the projection, in particular directly in each case.

[0018] The invention makes it possible to particularly advantageously adjust, i.e., vary, the quantity of exhaust gas flowing through the opening and thus the bypass channel, for example in the form of a volume and / or mass flow, so that particularly advantageous operation of the turbine can be achieved. In particular, an excessively large quantity of exhaust gas flowing through the opening at the beginning or in a first part of a movement of the valve element from the closed position into or towards the open position can be avoided, thereby making particularly advantageous operation of the turbine possible. In particular, the invention makes it possible to meter the quantity of exhaust gas flowing through the bypass channel more finely, i.e., more precisely, than with conventional solutions.For example, the valve element is in the intermediate position only or predominantly in the full-load range or full-load operation of the internal combustion engine and / or only or predominantly in an upper power range of the internal combustion engine.

[0019] The branching of the exhaust gas from the exhaust branch by means of the bypass duct is also referred to as blow-off, wherein the invention can avoid or reduce excessively large blow-off quantities at the beginning or in a first part of a movement of the valve element from the closed position to or towards the open position. The projection is or acts as a barrier, also referred to as a flow barrier, which prevents excessively large blow-off cross-sections, and thus excessively large flow cross-sections through which the exhaust gas can flow, and thus excessively large blow-off quantities, at the beginning or in a first, lower part of a movement of the valve element from the closed position to or towards the open position, thereby enabling advantageous operation of the turbine. This can, for example, enable a particularly advantageous setting of the boost pressure, in particular a control also referred to as boost pressure control.The exhaust gas flowing through the bypass duct is also referred to as blow-off flow or blow-off flow or forms a blow-off flow also referred to as blow-off flow.

[0020] The valve element is movable relative to the component, for example, within an adjustment range, wherein the aforementioned end positions belong to the adjustment range and are the ends of the adjustment range. Particularly with small opening paths or opening angles, and thus in a first, lower part of the adjustment range, which includes, for example, the closed position, excessively large blow-off quantities can be avoided, allowing the turbine power and thus the boost pressure to be advantageously adjusted.The invention is based in particular on the following considerations and findings: In conventional solutions, the quantity of exhaust gas flowing through the opening and thus the bypass channel, also referred to or designed as mass flow, increases, for example, at least almost linearly, when the valve element is opened, i.e. is moved from the closed position into or towards the open position relative to the component. Compared to such conventional solutions, the invention can reduce the quantity, i.e. the mass flow, so that an advantageously flat characteristic of the mass flow is created. The invention is particularly advantageous when the internal combustion engine is operated according to the Miller combustion process, whereby particularly low-emission operation can be achieved.In order to achieve advantageous operation and thus advantageous drivability of a motor vehicle having an internal combustion engine and driven by the internal combustion engine, much higher boost pressures than before are advantageous compared to conventional methods with conventional combustion processes, so that the mass flow of exhaust gas intended to drive the turbine wheel should increase. To this end, for example, the valve element is closed for a very large part of the engine operation of the internal combustion engine, i.e., it is held in the closed position or only very slightly opened, so that, for example, the valve element is closed for a very large part of the engine operation of the internal combustion engine, i.e., it is held in the closed position or only very slightly opened and thus, for example, held in the intermediate position.In this range, the amount of exhaust gas flowing through the opening and thus the bypass channel has a very significant influence on the boost pressure, so that small adjustment distances by which the valve element is moved relative to the component can result in a significant change in the boost pressure and thus in the performance of the internal combustion engine. Due to the aforementioned, advantageously flat characteristic, which can be realized by means of the invention, a greater scope, i.e., a larger range for adjusting, in particular regulating, the boost pressure can be realized compared to conventional solutions, so that the boost pressure can be adjusted, i.e., controlled or regulated, more precisely than with conventional solutions.The flat characteristic is to be understood in particular that, by means of the projection provided according to the invention, a flatter increase in the quantity of exhaust gas flowing through the opening and thus the bypass channel can be achieved compared to conventional solutions when the valve element is moved from the closed position into or towards the open position.Compared to conventional solutions, the projection, which acts as a barrier to the exhaust gas flowing through the opening and thus through the bypass channel, restricts the cross-sectional area through which the exhaust gas can flow, and in particular, a so-called isentropic flow cross-section, particularly for small opening paths or opening angles of the valve element. Thus, compared to conventional solutions, it leads to a flatter increase in the amount of exhaust gas flowing through the opening and thus through the bypass channel when the valve element is moved from the closed position to or toward the open position. Compared to conventional solutions, the amount of exhaust gas flowing through the opening and thus through the bypass channel is thus specifically reduced.Generally speaking, the projection, which is designed as a rib for example and acts as a flow barrier, can influence, in particular in a targeted manner, a characteristic of the quantity of exhaust gas flowing through the opening and thus the bypass channel resulting from a movement relative to the component. Only when the valve element is opened further from the intermediate position and is thus moved into or towards the open position, such that the valve element is further spaced from the valve seat than the projection is high from the valve seat, is the valve element no longer surrounded by the projection along its circumferential direction, in particular completely circumferentially, as a result of which the quantity of exhaust gas flowing through the opening and thus the bypass channel, and thus the aforementioned characteristic of the quantity of exhaust gas flowing through the opening, can approach conventional solutions or initial geometries.Due to the flatter increase in the characteristic, also known as the mass flow characteristic, i.e., the amount of exhaust gas flowing through the opening, which can be achieved according to the invention compared to conventional solutions, the turbine power and thus the boost pressure can be adjusted, in particular regulated, more precisely, so that the power of the internal combustion engine, for example, designed as a gasoline engine, can be adjusted more precisely and stably compared to conventional solutions. The aforementioned circumferential direction of the valve element coincides with the circumferential direction of the opening in the closed position of the valve element.

[0021] A further advantage of the invention is that, by means of the projection, at least a portion of the blow-off flow, in particular at least a predominant portion of the blow-off flow or the entire blow-off flow, can be prevented from flowing directly against an outer wall of the turbine housing that is spaced apart from the projection and the valve element and surrounds the projection and the valve element. The following was found: In the intermediate position, and if the projection were not provided, a portion of the valve seat and a portion of the valve element would define a gap through which the blow-off flow would flow. The blow-off flow would be guided or directed by the valve element in such a way that the blow-off flow would flow through the gap in such a direction, in particular obliquely to the passage direction of the opening, that the blow-off flow would flow directly against said outer wall of the turbine housing.By means of the projection, the blow-off flow can now be redirected, especially again, in such a way that the outer wall is protected from excessive, direct contact with the blow-off flow. This prevents the outer wall or a portion of the outer wall from being excessively heated by the blow-off flow.

[0022] For example, the valve element is designed as a poppet valve, which can be cylindrical on the outer circumference, at least in a length region of the valve element in the circumferential direction of the valve element, completely circumferentially. In order to be able to adjust the amount of exhaust gas flowing through the opening and thus the bypass channel, and thus the turbine power and thus the boost pressure, particularly precisely, and thus to realize particularly advantageous operation of the turbine, one embodiment of the invention provides that the valve element can be pivoted about a pivot axis relative to the component between the closed position and the open position. In order to thus pivot the valve element, for example, between the closed position and the open position and in particular the intermediate position, the valve element is or is pivoted or can be pivoted about the pivot axis by a respective adjustment angle.Thus, for example, the valve element has a first adjustment angle in the intermediate position and a second adjustment angle in the open position that is larger than the first adjustment angle, with the first adjustment angle and the second adjustment angle being, for example, greater than zero. In the closed position, for example, the valve element has a third adjustment angle that is smaller than the first adjustment angle and the second adjustment angle, which is, for example, zero. The respective adjustment angle is also referred to as the respective opening angle.The invention enables a particularly precise adjustment, in particular control, of the quantity of exhaust gas flowing through the opening and thus the bypass channel, particularly in the case of small adjustment or opening angles of the valve element that are larger than zero, whereby the turbine power and the boost pressure can be precisely adjusted, in particular in the case of small adjustment or opening angles of the valve element that are larger than zero.

[0023] In other words, the valve element can be pivoted about the pivot axis relative to the component within an adjustment range, wherein in particular the aforementioned end positions are ends of the adjustment range. Thus, the adjustment range extends, in particular precisely, from one of the end positions to the other end position and vice versa, so that the end positions belong to the adjustment range. Expressed again in other words, the adjustment range begins at one of the end positions and the adjustment range ends at the other end position and vice versa. The adjustment range comprises pivot positions of the valve element, which can be pivoted about the pivot axis relative to the component into the respective pivot position, wherein the open position, the closed position and the intermediate position are three of the pivot positions.In each pivoted position, the valve element has a respective adjustment angle, also referred to as the respective opening angle. The adjustment angle is zero or zero degrees in the closed position and increases toward the open position. Thus, the adjustment angle increases with increasing movement of the valve element from the closed position toward or towards the open position. In particular, the adjustment angle is maximum in the open position.

[0024] It has proven particularly advantageous if the valve element is at least or only partially surrounded by the projection in a range of the adjustment angle of the valve element extending from 0 degrees to a maximum of 14 degrees and at least 8 degrees in the circumferential direction of the opening and thus of the valve element, with respect to a pivoting of the valve element from the closed position into or towards the open position.

[0025] In particular, it has proven particularly advantageous if, with respect to pivoting the valve element from the closed position into or towards the open position, the valve element is arranged without overlap with the projection at the earliest from an adjustment or opening angle of 9 degrees, in particular of 15 degrees, so that, preferably with respect to pivoting the valve element from the closed position into or towards the open position, the valve element is no longer surrounded by the projection in the circumferential direction of the opening and thus of the valve element at the earliest from an opening angle of 9 degrees, in particular at the earliest from an opening angle of 15 degrees. As a result, the quantity of exhaust gas flowing through the opening can be adjusted, in particular regulated or controlled, particularly precisely, particularly at small opening angles.

[0026] In a further embodiment of the invention, a first plane extending perpendicular to the pivot axis and a second plane extending perpendicular to the flow direction of the exhaust gas flowing through the opening, which second plane is, for example, the plane in which the opening extends, extend obliquely or perpendicularly to each other. This allows the amount of exhaust gas flowing through the opening to be adjusted particularly precisely, particularly at small opening or positioning angles.

[0027] A further embodiment is characterized in that the projection is arranged at least or exclusively on a lift-off side of the valve element, the lift-off side of which, viewed in the first plane running perpendicular to the pivot axis, has a greater distance, in particular in the first plane and / or perpendicular to the pivot axis, than a second side of the valve element opposite the lift-off side. In other words, the lift-off side, viewed in the first plane, is arranged further away from the pivot axis than the second side. As a result, excessively large blow-off quantities can be avoided, particularly with small opening paths or opening angles of the valve element, so that the quantity of exhaust gas flowing through the opening can be adjusted particularly precisely.

[0028] The second side of the valve element is opposite the lift-off side. For example, when the valve element is opened, the lift-off side moves away from the valve seat faster, further, or higher than the opposite second side. This means that, for example, in the intermediate position, the lift-off side is further or higher from the valve seat than the opposite second side.

[0029] In order to be able to adjust the amount of exhaust gas flowing through the opening and thus the bypass channel in a particularly advantageous manner and thus to achieve particularly advantageous operation of the turbine, a further embodiment of the invention provides that a wall of the component forming the valve seat and the projection are designed integrally with one another, thus being formed from a single piece. This means that the wall and the projection are not designed separately from one another and connected to one another, but rather the wall and the projection are preferably designed from a single piece, thus being formed by a one-piece body, thus formed from a single piece and thus manufactured integrally and thus designed as a monoblock. Furthermore, it is possible for the component and the projection to be designed separately from one another and, in particular, directly, connected to one another.

[0030] In a further embodiment of the invention, a shape of the projection is adapted to a shape, particularly of the outer circumference, of the valve element, at least with respect to the closed position. This prevents excessively large blow-off quantities, so that the amount of exhaust gas flowing through the opening and thus the bypass channel can be adjusted particularly precisely.

[0031] It has proven particularly advantageous if the projection extends in a circular or circular arc shape in the circumferential direction of the opening, thereby enabling particularly advantageous operation of the turbine, since the amount of exhaust gas flowing through the opening can be adjusted particularly advantageously. It is conceivable that the projection, viewed in the circumferential direction of the opening, has a shape that differs from a circular shape or a circular arc shape, for example, being angular. In particular, the projection, viewed in the circumferential direction of the opening, has an outer peripheral shape that is adapted to an outer peripheral shape of the valve element that is opposite the shape in the closed position of the valve element.

[0032] In a further, particularly advantageous embodiment of the invention, the projection extends in the circumferential direction of the opening over a maximum of 270 degrees, in particular over a maximum of 180 degrees. This allows the amount of exhaust gas flowing through the opening and thus the bypass channel to be adjusted particularly advantageously, particularly across the entire adjustment range of the valve element, thereby enabling particularly advantageous operation of the turbine. Furthermore, it is conceivable for the projection to extend completely circumferentially around the opening and thus over 360 degrees around the opening.Finally, it has proven particularly advantageous if, in the closed position of the valve element, the greatest distance between the valve element and the projection, running perpendicular to the flow direction of the exhaust gas flowing through the opening, is at most 10 mm, in particular at most 5 mm, most particularly at most 3 mm, and particularly preferably at most 1.5 millimeters (mm). Preferably, the distance is at most or exactly 1.1 millimeters. This makes it possible to avoid excessively large blow-off quantities, thereby realizing particularly advantageous operation of the turbine, particularly at small opening angles or opening paths of the valve element.

[0033] A second aspect of the invention relates to an exhaust gas turbocharger, also referred to as a turbocharger or turbo, which has a turbine according to the first aspect of the invention. Advantages and advantageous embodiments of the first aspect of the invention are to be regarded as advantages and advantageous embodiments of the second aspect of the invention, and vice versa.

[0034] A third aspect of the invention relates to a motor vehicle, also simply referred to as a vehicle and preferably designed as a motor vehicle, in particular as a passenger car, which has an internal combustion engine, also referred to as an internal combustion engine, internal combustion engine, or motor, and designed, for example, as a reciprocating piston engine, i.e., a reciprocating piston motor, by means of which the motor vehicle can be driven. The internal combustion engine has an exhaust gas turbocharger according to the second aspect of the invention. Advantages and advantageous embodiments of the first aspect and the second aspect are to be regarded as advantages and advantageous embodiments of the third aspect of the invention, and vice versa.

[0035] Further details of the invention will become apparent from the following description of a preferred embodiment with the accompanying drawings. In the drawings: Fig. 1 shows a partial schematic perspective view of a turbine for an exhaust gas turbocharger of an internal combustion engine; Fig. 2 a partial schematic and sectional perspective view of the turbine; Fig. 3 a partial schematic sectional view of the turbine; and Fig. 4 a diagram illustrating an operation of the turbine.

[0036] In the figures, identical or functionally identical elements are provided with the same reference symbols.

[0037] Fig. 1 shows a detail in a schematic perspective view of a turbine 1 for an exhaust gas turbocharger of an internal combustion engine. The internal combustion engine is preferably part of a motor vehicle, also simply referred to as a vehicle, which can be driven by the internal combustion engine. The turbine 1 has a turbine housing 2 designed as a solid body, which is thus a component of the turbine 1. The turbine 1 has a turbine wheel (not visible in the figures) which is arranged in the turbine housing 2 so as to be rotatable about an axis of rotation relative to the turbine housing 2. During its fired operation, the internal combustion engine provides exhaust gas which can flow through an exhaust tract of the internal combustion engine. The turbine 1 and thus the turbine housing 2 are arranged in the exhaust tract so that the exhaust gas can flow through the turbine housing 2.The exhaust gas of the internal combustion engine can flow onto the turbine wheel and thereby drive it, whereby the turbine wheel is rotated about the axis of rotation relative to the turbine housing 2.

[0038] Particularly good looking Fig. 3 it can be seen that the turbine 1 has a bypass channel 3, also referred to as a wastegate or wastegate channel, through which at least a portion of the exhaust gas flowing through the exhaust tract can flow. It can be seen that the bypass channel 3 runs at least partially in the turbine housing 2, in this case such that at least a portion of the bypass channel 3 is delimited, in particular directly, by an inner circumferential surface 4 of the turbine housing 2. The turbine housing 2 is arranged, for example, in an exhaust gas branch of the exhaust tract through which the exhaust gas can flow. In this case, the bypass channel 3 is fluidly connected, for example, to the exhaust gas branch at a first connection point and at a second connection point V1.In the flow direction of the exhaust gas flowing through the exhaust tract and in particular the exhaust branch, the first connection point is arranged upstream of the turbine wheel, and in the flow direction of the exhaust gas flowing through the exhaust branch, the second connection point V1 is arranged downstream of the turbine wheel. The bypass duct 3 has an opening 5, which is delimited, in particular directly, by the turbine housing 2, in this case by an edge R of the turbine housing 2. The edge R completely surrounds the opening 5 in the circumferential direction of the opening 5. Since the opening 5 is formed, in particular designated and very particularly delimited or directly delimited by the turbine housing 2, the turbine housing 2 has the opening 5. In this case, the opening 5 is an outlet opening, also referred to as an outflow opening, via which the aforementioned part of the exhaust gas introduced into the bypass duct 3 can be discharged, i.e., led out, from the bypass duct 3.

[0039] Via an inlet opening of the bypass duct 3, at least the aforementioned part of the exhaust gas flowing through the exhaust branch can be branched off from the exhaust branch at the first connection point and introduced into the bypass duct 3. The exhaust gas branched off from the exhaust branch and introduced into the bypass duct 3 via the inlet opening can be guided to the second connection point V1 by means of the bypass duct 3 and discharged from the bypass duct 3 at the second connection point V1 via the opening 5 arranged in particular at the second connection point V1 and thereby, in particular, reintroduced into the exhaust branch, wherein the exhaust gas flowing through the bypass duct 3 bypasses the turbine wheel, thus does not flow against it and thus does not drive it.This means that the turbine wheel can be bypassed or is bypassed via the bypass channel 3 by the exhaust gas introduced into the bypass channel 3 via the inlet opening and flowing through the bypass channel 3 and the opening 5.

[0040] The turbine housing 2 has the opening 5 and a valve seat 6, which extends completely in the circumferential direction of the opening 5, i.e. completely circumferentially, around the opening 5. The opening 5 is thus completely circumferentially surrounded by the valve seat 6 along its circumferential direction. In the present case, the valve seat 6 is a surface, also referred to as a valve seat surface, which extends, for example, in a plane in which, for example, the opening 5 also extends. During operation of the turbine 1, wherein the opening 5 is at least partially open during operation and exhaust gas from the bypass duct 3 thus flows through the opening 5 and thus flows out of the bypass duct 3 via the opening 5 and flows into the exhaust gas branch, the exhaust gas flowing through the opening 5 and thus flowing out of the bypass duct 3 via the opening 5 flows in a flow direction through the opening 5.The flow direction is illustrated by an arrow 7 and runs perpendicular to the plane in which the opening 5 extends. The circumferential direction of the opening 5 extends around the flow direction of the exhaust gas flowing through the opening 5, illustrated by the arrow 7, and is shown in . Fig. 3 by a double arrow 8, wherein the circumferential direction of the opening 5 extends, for example, in the plane in which the opening 5 extends. In particular, the flow direction illustrated by the arrow 7 coincides with a passage direction of the opening 5, which, when viewed solely by the turbine housing 2, is continuous along the passage direction and through which a gas, such as the exhaust gas, can flow.

[0041] The turbine 1 also has a valve element 9, which in this case is designed as a poppet valve. The valve element 9 is movable relative to the turbine housing 2 between a closed position S and an open position (not shown in the figures), in this case such that the valve element 9 is pivotable relative to the turbine housing 2 about a pivot axis SA between the closed position S and the open position. A first plane extending perpendicular to the pivot axis SA and the plane extending perpendicular to the flow direction of the exhaust gas flowing through the opening 5, also referred to as the second plane, extend obliquely or perpendicularly to one another.

[0042] In the closed position S, the valve element 9 sits directly on the corresponding valve seat 6, whereby in the closed position S the opening 5 and thus the bypass channel 3 are fluidically blocked by the valve element 9. In the open position, the valve element 9 at least partially opens the opening 5 and thus the bypass channel 3, wherein in the present case in the open position O at least a portion of the valve element 9 is lifted off the valve seat 6 and thus spaced from the valve seat 6. In the exemplary embodiment shown in the figures, it is provided that in the open position O the entire valve element 9 is lifted off the valve seat 6, so that in the open position of the valve element 9 the entire valve element 9 is spaced from the valve seat 6.

[0043] Particularly good looking Fig. 1 and Fig. 2 that the valve element 9 is part of a valve device 10 which has the valve element 9 and a pivot arm 11. The valve element 9 is, for example, formed separately from the pivot arm 11 and, in particular, is coupled to the pivot arm 11 so as to be pivotable relative to the pivot arm 11. The pivot arm 11 and, with it, the valve element 9, are pivotable about the pivot axis SA relative to the turbine housing 2 between the closed position S and the open position. In this case, a bearing 12 is provided, for example, by means of which the pivot arm 11 and thus the valve element 9 are mounted on the turbine housing 2 so as to be pivotable about the pivot axis SA relative to the turbine housing 2.By means of the valve element 9, that is to say by pivoting the valve element 9 relative to the turbine housing 2 and about the pivot axis SA, a quantity of exhaust gas, designed for example as a volume flow and / or mass flow, flowing through the opening 5 and thus the bypass channel 3 can be adjusted, in particular controlled or regulated.

[0044] The quantity of exhaust gas flowing through the opening 5 and thus the bypass channel 3 is also referred to as the quantity of exhaust gas flowing through the opening 5 and thus the bypass channel 3.

[0045] In order to be able to adjust the amount of exhaust gas flowing through the opening 5 and thus the bypass channel 3 particularly precisely, especially with small opening paths or opening angles of the valve element 9, the preferably one-piece turbine housing 2 has a projection 13, which is also referred to as a barrier or flow barrier or functions as a barrier or flow barrier. Fig. 2 and Fig. 3 it can be seen that the projection 13 projects from the valve seat 6, in particular in a projection direction illustrated by an arrow 14, which runs perpendicular to the aforementioned plane in which the opening 5 extends and corresponds to the flow direction of the exhaust gas flowing through the opening 5, illustrated by the arrow 7. The projection 13 is thus raised relative to the valve seat 6, in particular along the projection direction. Thus, the projection direction and an opening direction, in which the valve element 10 is opened, and thus pivoted from the closed position S into or towards the open position, run or point in the same direction. In the exemplary embodiment shown in the figures, the projection 13 extends in the circumferential direction of the opening 5 only partially around the opening 5, so that in the exemplary embodiment shown in the figures, the opening 5 is only partially surrounded by the projection 13 along its circumferential direction.This means that the projection 13 extends in the circumferential direction of the opening 5 over less than 360 degrees around the opening 5, in the present case in particular such that the projection 13 extends in the circumferential direction of the opening 5 over at most 170 degrees, in particular over at most 240 degrees and most particularly over 180 degrees, around the opening 5.

[0046] The valve element 9, the circumferential direction of which in the closed position S coincides with the circumferential direction of the opening 5, is in the closed position S as well as in at least one intermediate position Z of the valve element 9 lying between the closed position S and the open position, which in the intermediate position Z at least partially opens the opening 5 and thereby the bypass channel 3, in the circumferential direction of the opening 5 and thus of the valve element 9, in this case only partially surrounded by the projection 13, so that the valve element 9, both in the closed position S and in the intermediate position Z, is overlapped by the projection 13 along a direction perpendicular to the flow direction of the exhaust gas flowing through the opening 5, namely over such a first extension of the valve element 9 running in the circumferential direction of the valve element 9 and thus of the opening 5,whose first extension corresponds to a second extension of the projection 13 running in the circumferential direction of the opening 5. If the projection 13 were to extend completely around the opening 5 in the circumferential direction of the opening 5, the second extension of the projection 13 would be 360 ​​degrees. However, since in the exemplary embodiment shown in the figures the projection 13 does not extend completely around the opening 5 in the circumferential direction of the opening 5, but only partially around the opening 5, the second extension in the exemplary embodiment shown in the figures is less than 360 degrees. For example, the second extension is at most 270 degrees, in particular at most 240 degrees, and most particularly at most 180 degrees.

[0047] In the open position of the valve element 9, the valve element 9 is arranged without overlapping with the projection 13, so that in the open position of the valve element 9, the entire valve element 9 is no longer overlapped by the projection 13 along the aforementioned direction running perpendicular to the flow direction of the exhaust gas flowing through the opening 5.

[0048] In the exemplary embodiment shown in the figures, the valve element 9 can be pivoted relative to the turbine housing 2 within or over an adjustment range about the pivot axis SA, wherein the adjustment range comprises the closed position S as a first end of the adjustment range and the open position as a second end of the adjustment range. Thus, the adjustment range begins in the open position and ends in the closed position S, or vice versa. The adjustment range also includes the intermediate position Z, which lies in the adjustment range between the open position and the closed position S. The adjustment range includes pivot positions of the valve element 9, which can be pivoted into the respective pivot position of the adjustment range by pivoting the valve element 9 about the pivot axis SA and relative to the turbine housing 2.Thus, the open position, the closed position S and the intermediate position Z are three of the pivot positions of the adjustment range. The valve element 9 can be pivoted about the pivot axis SA relative to the turbine housing 2 by a respective adjustment angle, also referred to as the respective opening angle, and can thereby be pivoted into the respective pivot position of the adjustment range, so that the respective pivot position corresponds to a respective adjustment angle of the valve element 9, i.e. with a respective value of the adjustment angle of the valve element 9. In the closed position S the adjustment angle is 9. With increasing pivoting of the valve element 9 from the closed position S into or towards the open position, the adjustment angle, also referred to as the opening angle, increases.Preferably, it is provided that, with respect to a pivoting of the valve element 9 from the closed position S into or towards the open position, the valve element 9 is arranged without overlap with the projection 13 at the earliest from an adjustment angle of 9 degrees, in particular of 15 degrees, and is surrounded in front of it by the projection 13 in the circumferential direction of the valve element 9 and the opening 5, whereby the quantity of exhaust gas flowing through the opening 5 and thus the bypass channel 3, also referred to as the blow-off quantity, can be adjusted particularly precisely, in particular with small, thus low adjustment angles or opening angles of the valve element 9.

[0049] Out of Fig. 2 and Fig. 3 it can be seen that the projection 13 is arranged on a lifting side AHS of the valve element 9, the lifting side AHS of which lifts off from the valve seat 6 more quickly when the valve element 9 is pivoted from the closed position S into the open position than a second side of the valve element 9 opposite the lifting side AHS of the valve element 9. Thus, in the intermediate position z, the lifting side AHS is further spaced from the valve seat 6 than the opposite second side. Thus, a through-flow opening delimited in the intermediate position on the one hand directly by the valve seat 6 and on the other hand directly by the valve element 9, through which flow in the intermediate position Z the exhaust gas flows between the valve seat 6 and the valve element 9 and thus through the opening 5, is wedge-shaped, in particular viewed in a plane in which the flow direction of the exhaust gas flowing through the opening 5 runs.In addition, a wall W of the turbine housing 2 forming the valve seat 6 is formed integrally with the projection 13.

[0050] Particularly good looking Fig. 1 and Fig. 2 it can be seen that the projection 13 extends in the circumferential direction of the opening 5 in a circular arc. Fig. 3 shows a further effect of the projection 13. The projection 13 prevents the exhaust gas flowing through the opening 5 and thus out of the bypass channel 3 from flowing directly against an outer wall WA of the turbine housing 2, which outer wall WA is spaced apart from the projection 13 and the valve element 9 and surrounds the projection 13 and the valve element 9. This prevents the outer wall WA or a portion of the outer wall WA from being excessively heated by the exhaust gas flowing through the opening 5.

[0051] Fig. Fig. 4 shows a diagram illustrating an operation of the turbine 1 and in particular an effect of the valve element 9 and the projection 13. On the ordinate 15 of the Fig. 4, the blow-off quantity, i.e. the quantity of exhaust gas flowing through the opening 5 and thus the bypass channel 3, is plotted, and on the abscissa 16 of the Fig.4, the adjustment angle of the valve element 9, also referred to as the opening angle, is plotted; the adjustment angle of the valve element 9 increases in a direction indicated by an arrow 17 along the abscissa 16. A curve 18 illustrates a curve of the blow-off quantity over the adjustment angle in a conventional turbine. A linear curve of the blow-off quantity can be seen, in particular such that the blow-off quantity increases linearly with increasing opening angle or adjustment angle. A curve 19 illustrates the blow-off quantity over the opening or adjustment angle in turbine 1. It can be seen that curve 19 is significantly flatter than curve 18 at small opening angles, so that at small opening angles of the valve element 9, the blow-off quantity in turbine 1 is lower than in conventional turbines.This allows the blow-off quantity to be adjusted more precisely compared to conventional solutions, particularly at small opening angles of the valve element 9. List of reference symbols 1 turbine 2 turbine housings 3 Bypass channel 4 inner circumferential surface 5 Opening 6 Valve seat 7 Arrow 8 Arrow 9 Valve element 10 Valve device 11 Swivel arm 12 Storage 13 lead 14 Arrow 15 Ordinates 16 Abscissa 17 Arrow 18 History 19 History AHS take-off side R edge S Closed position SA swivel axis V1 second connection point WA exterior wall Z intermediate position QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] CN 109072770 B

[0002] DE 10 2013 002 894 B4

[0002] US 9 322 327 B2

[0002] JP 6098314 B2

[0002]

Claims

[1] Turbine (1) for an exhaust gas turbocharger, with a turbine wheel driven by exhaust gas, with a bypass channel (3) which has an opening (5) via which at least a portion of the exhaust gas can be introduced into the bypass channel (3) or exhaust gas introduced into the bypass channel (3) can be discharged from the bypass channel (3), via which the turbine wheel can be bypassed by the exhaust gas introduced into the bypass channel (3) and flowing through the bypass channel (3), with a component (2) through which the exhaust gas can flow and which has the opening (5), which also has a valve seat (6), wherein the opening (5) is completely surrounded by the valve seat (6) along its circumferential direction (8), and with a valve element (9) which can be moved relative to the component (2) between a closed position (S) fluidically blocking the opening (5) and thereby the bypass channel (3), in which the valve element (9) rests on the valve seat (6) sits,and at least one open position which at least partially releases the opening (5) and thereby the bypass channel (3), characterized by , that: - the component (2) has a projection (13) projecting from the valve seat (6) which extends at least partially around the opening (5) in the circumferential direction (8) of the opening (5); - the valve element (9) is at least partially surrounded by the projection (13) in the circumferential direction (8) of the opening (5) both in the closed position (S) and in an intermediate position (Z) of the valve element (9) lying between the closed position (S) and the open position, which in the intermediate position (Z) at least partially releases the opening (5) and thereby the bypass channel (3); and - in the open position of the valve element (9), the valve element (9) is arranged without overlapping with the projection (13). [2] Turbine (1) according to claim 1, characterized bythat the valve element (9) can be pivoted about a pivot axis (SA) relative to the component (2) between the closed position (S) and the open position. [3] Turbine (1) according to claim 2, characterized by that a first plane running perpendicular to the pivot axis (SA) and a second plane running perpendicular to the flow direction (7) of the exhaust gas flowing through the opening (5) run obliquely or perpendicular to one another. [4] Turbine (1) according to claim 2 or 3, characterized by that the projection (13) is arranged at least on one lifting side (AHS) of the valve element (9), the lifting side (AHS) of which, viewed in a plane running perpendicular to the pivot axis (SA), has a greater distance than a second side of the valve element (9) opposite the lifting side (AHS). [5] Turbine (1) according to one of the preceding claims, characterized bythat a wall (W) of the component (2) forming the valve seat (6) and the projection (13) are formed integrally with one another. [6] Turbine (1) according to one of the preceding claims, characterized by that the projection (13) extends in a circular or circular arc-shaped manner in the circumferential direction (8) of the opening (5). [7] Turbine (1) according to one of the preceding claims, characterized by that the projection (13) extends in the circumferential direction (8) of the opening (5) over a maximum of 270 degrees, in particular over a maximum of 180 degrees. [8] Turbine (1) according to one of the preceding claims, characterized bythat in the closed position (S) of the valve element (9), the greatest distance between the valve element (9) and the projection (13) running perpendicular to the flow direction (7) of the exhaust gas flowing through the opening (5) is at most 10 millimeters, in particular at most 5 millimeters, very particularly at most 3 millimeters and particularly preferably at most 1.5 millimeters. [9] Exhaust gas turbocharger, with a turbine (1) according to one of the preceding claims. [10] Motor vehicle, comprising an internal combustion engine by means of which the motor vehicle can be driven, wherein the internal combustion engine has an exhaust gas turbocharger according to claim 9.

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