Internal combustion engine for a motor vehicle, in particular a motor car, and motor vehicle

Abstract

The invention relates to an internal combustion engine (10) for a motor vehicle, having an exhaust branch (18) through which exhaust gas from at least one combustion chamber (16a-d) of the internal combustion engine (10) can flow, an exhaust turbocharger (22) comprising a turbine (26) which is arranged in the exhaust branch (18) and has a turbine housing (42) and a turbine wheel (30) which is at least partially accommodated in the turbine housing (42) and can be driven by the exhaust gas, and at least one secondary air duct (38) through which secondary air can flow and which opens into the exhaust branch (18), by means of which secondary air duct the secondary air flowing through the secondary air duct (38) can be fed into the exhaust gas flowing through the exhaust branch (18), wherein the secondary air duct (38) opens into the exhaust branch (18) within the turbine housing (42).

Description

Technical Field

[0001] This invention relates to an internal combustion engine for motor vehicles, particularly automobiles. The invention also relates to a motor vehicle, particularly an automobile. Technical Field

[0003] DE 10 2016 117 961 A1 discloses an exhaust gas system for a motor vehicle operating with combustion technology, incorporating a turbocharger, wherein exhaust gas is supplied from the cylinders of an internal combustion engine to a twin-scroll turbine via at least one separate exhaust gas bend, and a secondary air system for introducing fresh air into the exhaust gas is also included. Furthermore, DE 10 2019 101 576 A1 discloses an apparatus for treating exhaust gas from an internal combustion engine. Additionally, DE 10 2017 106 164 A1 discloses an exhaust gas turbocharger. Furthermore, EP 1 876 335 A1 discloses a turbine. DE 10 2010 053 057 A1 discloses a supercharging device for an internal combustion engine. Furthermore, DE 102 60 779 A1 discloses an exhaust gas turbocharger for an internal combustion engine. DE 1O 2015 006 288 A1 also discloses a turbine for an exhaust gas turbocharger. Summary of the Invention

[0004] The objective of this invention is to provide an internal combustion engine for a motor vehicle and a motor vehicle having such an internal combustion engine, thereby enabling particularly advantageous secondary air guidance.

[0005] This task is accomplished by an internal combustion engine having the following characteristics and a motor vehicle having the following characteristics.

[0006] The first aspect of the invention relates to an internal combustion engine, also known as an internal combustion engine and preferably designed as a piston engine or piston machine, for motor vehicles, particularly preferably designed as passenger cars or trucks. This means that the motor vehicle includes an internal combustion engine in its fully manufactured state and can be driven by means of the internal combustion engine. The internal combustion engine has at least one combustion chamber. In particular, the internal combustion engine may have multiple, and therefore at least two or more, combustion chambers. During the ignition operation of the internal combustion engine, a combustion process takes place in the respective combustion chamber, and the respective fuel-air mixtures, also simply referred to as mixtures within that chamber, are burned. This produces exhaust gases from the internal combustion engine. In other words, exhaust gases from the internal combustion engine arise from the individual combustion of the mixtures in the respective combustion chambers.

[0007] Here, the internal combustion engine has an exhaust gas branch through which exhaust gases from at least one combustion chamber, or all of these combustion chambers, can flow; this is also referred to as an exhaust gas device or exhaust gas system. At least one exhaust gas treatment device can be arranged in the exhaust gas branch for treating the exhaust gases. The exhaust gas treatment device can be designed to remove at least one component of the exhaust gases. This may particularly mean that the exhaust gas treatment device is designed, for example, to filter out particulate matter, especially carbon black particles, from the exhaust gases. For this purpose, the exhaust gas treatment device may include a particulate filter. Alternatively or additionally, the exhaust gas treatment device can catalyze or achieve catalytic activity for at least one chemical reaction. This particularly means that the exhaust gas treatment device can be designed to catalyze and / or cause a chemical reaction. In the chemical reaction, for example, at least one component of the exhaust gases reacts with at least another substance and at least one chemical reaction product, thereby removing at least one component from the exhaust gases by chemical reaction. For this purpose, the exhaust gas treatment device may, for example, have an oxidation catalyst and / or an SCR catalyst. Furthermore, the internal combustion engine has an intake branch, also called an intake branch, through which at least fresh air can flow. Fresh air flowing through the intake manifold can be directed to and enter the combustion chambers of the internal combustion engine, particularly multiple combustion chambers. Additionally, liquid fuel can be added, especially through direct injection, into each combustion chamber. The fuel and fresh air form the aforementioned fuel-air mixture.

[0008] The internal combustion engine also includes at least one exhaust gas turbocharger, which comprises a turbine disposed in the exhaust gas branch and thus through which exhaust gas flows. The turbine has a turbine housing and a turbine impeller, which is at least partially, especially at least primarily or completely, arranged within the turbine housing and rotatable about a rotor axis relative to the turbine housing. The exhaust gas turbocharger has at least one compressor disposed in the intake branch, which includes a compressor impeller disposed in the intake branch. The compressor impeller is preferably at least partially, especially at least primarily and thus more than half, and more preferably completely disposed outside the turbine housing. The compressor impeller, particularly via the shaft of the exhaust gas turbocharger, can be driven by the turbine impeller, wherein driving the compressor impeller compresses the fresh air flowing through the intake branch. The fresh air compressed by the compressor impeller, also referred to as boosted air, can be supplied to the respective combustion chambers. Boosted air can be supplied to the respective combustion chambers.

[0009] The internal combustion engine also has at least one secondary air passage through which secondary air can flow and into the exhaust gas branch, thereby allowing the secondary air flowing through the secondary air passage to be delivered into the exhaust gas branch or into the exhaust gas flowing through the exhaust gas branch, in particular bypassing all the combustion chambers of the internal combustion engine. The preferred feature of this arrangement, "the secondary air flowing through the secondary air passage can be delivered into the exhaust gas branch or into the exhaust gas flowing through the exhaust gas branch by means of the secondary air passage," means that the secondary air flowing through the secondary air passage preferably bypasses all the combustion chambers of the internal combustion engine and therefore does not flow through any of the combustion chambers of the internal combustion engine. In particular, the secondary air flowing through the secondary air duct can be guided and fed into the exhaust gas flowing through the exhaust gas branch in such a way that, at least before the secondary air is fed into the exhaust gas branch or into the exhaust gas flowing through the exhaust gas branch, that is, at least before the secondary air flows out of the secondary air duct and into the exhaust gas branch or into the exhaust gas flowing through the exhaust gas branch, the secondary air is prohibited from participating in combustion. Therefore, the secondary air is not burned, that is, it is not used to oxidize substances, especially fuels. With the help of the secondary air fed into the exhaust gas flowing through the exhaust gas branch, the aforementioned exhaust gas treatment device can be heated very intensely for a short time, for example, in such a way that the secondary air fed into the exhaust gas flowing through the exhaust gas branch forms a secondary air-fuel mixture together with, for example, the unburned and combustible fuel portion contained in the exhaust gas, which can be combusted exothermically in the exhaust gas branch. The secondary air fed into the exhaust gas branch or into the exhaust gas flowing through the exhaust gas branch thus participates in the combustion of the secondary air-fuel mixture and is thus used to oxidize the fuel portion. Specifically, the oxygen contained in the secondary air supplied to the exhaust gas flowing through the exhaust gas branch is used to oxidize the previously unburned fuel portion during the combustion of the secondary air-fuel mixture. However, the secondary air participates in the combustion of the secondary air-fuel mixture only under the following conditions: it is only after the secondary air has been supplied to the exhaust gas branch or to the exhaust gas flowing through the exhaust gas branch, and therefore only after it flows out of the secondary air duct and into the exhaust gas branch or into the exhaust gas flowing through the exhaust gas branch, that the secondary air is either burned or used for the oxidation of the fuel portion. In other words, the secondary air only participates in the combustion of the secondary air-fuel mixture in the exhaust gas branch, or the secondary air is only used for the oxidation of the fuel portion in the exhaust gas branch, and thus only after it flows out of the secondary air duct and into the exhaust gas branch or into the exhaust gas flowing through the exhaust gas branch, does the secondary air participate in the combustion of the secondary air-fuel mixture or for the oxidation of the fuel portion.

[0010] By means of the released heat, such as in an exhaust gas treatment device, the device can be heated and thereby reach or exceed its starting temperature, also known as the ignition temperature. The secondary air-fuel mixture is combusted, for example, by means of an electrically operated ignition mechanism, such as a heated spark plug, located in the exhaust gas branch, or by means of a hot component, particularly in the exhaust gas branch of the exhaust gas treatment device. This component is, for example, the catalyst of the exhaust gas treatment device, particularly one or more of the aforementioned oxidation catalysts.

[0011] The internal combustion engine has a valve that allows regulation of the amount of secondary air flowing through the secondary air passage. This can be, for example, referring to the ability of the valve to adjust the flow cross-section through which secondary air can flow, thus making the amount of secondary air flowing through the secondary air passage adjustable. Specifically, the feature that "the amount of secondary air flowing through the secondary air passage can be regulated by means of the valve" can mean that the valve is adjustable or switchable between at least two states. In a first state of the valve, for example, a first value for the amount of secondary air flowing through the secondary air passage is present, where, perhaps except for possible technically determined leaks, the first value can be zero. Therefore, for example, the first state is a closed state, where, perhaps except for the aforementioned possible technically determined leaks, the valve closes the secondary air passage. Thus, secondary air cannot flow through the secondary air passage. In a second state, for example, a second value, greater than zero and greater than the first value, is present through the valve, thereby opening the secondary air passage in the second state. Therefore, the second state is, for example, a released state, where secondary air can flow through the secondary air passage. In other words, the amount of secondary air flowing through the secondary air passage is greater than in the first state, for example, in the second state. It is also conceivable that the valve can be adjusted in at least one or more other states, wherein in these other states, the amount of secondary air flowing through the secondary air passage is a value greater than zero that is not the first or second value, or a value that is not preferably greater than zero that is not the first or second value. "Introducing secondary air into the exhaust gas branch or into the exhaust gas flowing through the exhaust gas branch" is also referred to as secondary air introduction, secondary air supply, or secondary air injection.

[0012] To achieve a particularly simple and cost-effective, weight- and structurally space-efficient method for guiding and delivering secondary air into or through the exhaust gas branch, this invention specifies that the secondary air duct connects to the exhaust gas branch within the turbine housing. Specifically, this means that the secondary air duct terminates within the turbine housing and thus connects to the exhaust gas branch within the turbine housing, allowing the secondary air flowing through the secondary air duct to flow out of and into the exhaust gas flowing through the turbine housing and the exhaust gas branch. In other words, the secondary air duct terminates at its exhaust gas branch end, with this end of the secondary air duct arranged within, and particularly through, the turbine housing. This provides a particularly advantageous pressure drop between this end of the secondary air duct and the supply point, where secondary air can be supplied to and thus delivered into the secondary air duct. In particular, it can ensure that at least in almost every operating state of the internal combustion engine, there is a higher pressure at the supply point than at this end of the secondary air passage, so that secondary air can be advantageously supplied to the secondary air passage at the supply point without additional pumps, actuators, valves or other different independent components. The secondary air passage, and especially based on the pressure drop, can be supplied to this end and at this end can be supplied to the exhaust gas branch or to the exhaust gas flowing through the exhaust gas branch.

[0013] The secondary air duct is connected or may be connected to the intake branch at the supply point via the aforementioned valve, so that at the supply point, also known as the diversion point, at least a portion of the fresh air, especially delivered and / or compressed by the compressor wheel, can be diverted from the intake branch and sent into the secondary air duct via the valve, and can be sent as secondary air into the exhaust gas branch or into the exhaust gas flowing through the exhaust gas branch. In other words, at the supply point (diversion point), at least the aforementioned portion of the fresh air can be diverted from the intake branch, i.e., sent out from the intake branch. The portion of fresh air diverted from the intake branch is sent into the secondary air duct, especially via the valve. A portion of the fresh air supplied to the secondary air duct, or particularly the fresh air supplied to the secondary air duct via a valve, can be used as secondary air and sent to and into the exhaust gas branch via the secondary air duct. This ensures that the diverted portion of the fresh air, in its path from the diversion point (supply point) to the exhaust gas branch or this end, flows, for example, past the valve and therefore preferably bypasses at least one combustion chamber, and especially all, of the internal combustion engine; that is, it does not flow through any combustion chamber of the internal combustion engine. Furthermore, it is preferably specified that the fresh air diverted from the intake branch does not participate in combustion in its path from the supply point to this end of the secondary air duct; therefore, secondary air or the fresh air forming secondary air is prohibited from participating in combustion from the diversion point to this end of the secondary air duct. Therefore, it is preferably specified that the fresh air from the intake branch is used as secondary air.

[0014] The supply point (splitter) is located downstream of the compressor impeller and, in particular, upstream of at least one or all of the combustion chambers of the internal combustion engine. For example, the splitter is located upstream of a throttle valve in the intake branch, in the direction of fresh air flow through the intake branch. The throttle valve regulates the amount of fresh air to be supplied to at least one or more combustion chambers. If, for example, a previously open throttle valve is closed, at least the aforementioned portion of the fresh air supplied or compressed by the compressor impeller, pre-positioned between the compressor impeller and the subsequently closed throttle valve, can be diverted from the intake branch at the splitter (supply point), particularly guided by valves into the secondary air duct and subsequently the exhaust gas duct. This avoids over-braking of the compressor impeller caused by compressed fresh air pre-positioned between the compressor impeller and the throttle valve. Therefore, the present invention can combine a so-called schubumluft system with a secondary air system. In this case, the valve can have a dual function; thus, the valve can be designed, for example, as a combination valve. On the one hand, the valve can be used to regulate the secondary air flowing through the secondary air passage and into the exhaust gas flowing through the exhaust gas branch, thus functioning as a secondary air valve. On the other hand, the valve can be used as a so-called shunting air recirculation valve (Schubumluftventil, USV) to divert at least a portion of the aforementioned fresh air from the intake branch, sending it into the secondary air passage and then into the exhaust gas flowing through the exhaust gas branch, thereby using it as secondary air. Therefore, for example, an additional separate shunting air recirculation system can be avoided, allowing the number of internal combustion engine parts, weight, structural space requirements, and cost to be kept very low.

[0015] By designing the valves as combination valves and arranging the supply points (diversion points), a compressor wheel can be used to deliver, for example, secondary air, especially air through a secondary air passage. Therefore, the compressor wheel can be used as a secondary air pump, also known as an air pump, to deliver secondary air, for example, into and / or through a secondary air passage. This avoids the need for an additional separate delivery mechanism for secondary air, thus keeping the cost, number of parts, weight, and structural space requirements of the internal combustion engine very low. Using the compressor wheel as a secondary air pump is also advantageous in terms of providing a high pressure drop or achieving a large secondary air mass flow and / or volume flow. This specifically means that a large amount of oxygen, also known as oxygen content, contained in the secondary air delivered by the compressor wheel can be fed into the exhaust gas branch or into the exhaust gas flowing through the exhaust gas branch, thereby allowing for efficient heating, for example, by an exhaust gas treatment device.

[0016] The secondary air duct has at least one outlet hole at its exhaust gas branch end, where the secondary air duct terminates and connects to the exhaust gas branch. Therefore, secondary air flowing through the secondary air duct can be discharged from the secondary air duct through the outlet hole and thus fed into the exhaust gas branch and, consequently, into the exhaust gas flowing through the exhaust gas branch. Therefore, the outlet hole is also located at the exhaust gas branch end of the secondary air duct.

[0017] To guide secondary air, particularly into the exhaust gas branch and thus into the exhaust gas flowing through it, in a manner advantageous in terms of structural space, weight, and cost, a secondary air duct is specified to connect to the exhaust gas branch at an inlet located within the turbine housing. This inlet is positioned downstream of at least a portion, particularly at least a major portion, of the turbine impeller in the direction of exhaust gas flow through the turbine housing. "At least a major portion of the turbine impeller" refers to at least more than half the axial length of the turbine impeller. By arranging the inlet downstream of at least a portion of the turbine impeller, a highly advantageous pressure drop between the supply point and the inlet can be achieved, where, for example, one end of the secondary air duct is located at the inlet. This ensures, in particular, that the pressure at the supply point is sufficiently high and, comparatively, sufficiently low, that the pressure at the inlet is low enough to allow a significant amount of secondary air to be supplied into the exhaust gas flowing through the exhaust gas branch without the need for additional separate components such as valves or pumps.

[0018] The inlet point at the end of the exhaust gas branch of the secondary air duct is located in the turbine outlet area, through which the turbine impeller blades are traversed by the exhaust gas. This means that during turbine operation, the exhaust gas flows towards and around the turbine impeller blades, thereby driving the turbine impeller. The exhaust gas then flows away from the impeller blades, into the outlet area, and through the outlet area. Therefore, the outlet area is preferably located downstream of the impeller blades in the direction of exhaust gas flow through the turbine housing. It is particularly conceivable that these or all of the impeller blades are arranged entirely within the aforementioned portion of the turbine impeller. The inlet point does not necessarily have to be located downstream of the entire turbine impeller. It is also preferred that the inlet point be located downstream of at least a portion of the turbine impeller, particularly downstream of these or all of the impeller blades. This ensures that a sufficiently low pressure exists at the inlet point during at least almost all operating conditions of the internal combustion engine, lower than the other pressure present at the supply point, thus resulting in a sufficiently large pressure drop. The pressure drop is specifically the ratio of the other pressure present at the supply point to the pressure present at the inlet point. The higher the pressure drop, the easier and more advantageous it is for secondary air to be fed into the exhaust gas flowing through the exhaust gas branch, where the pressure drop can be designed to be very high by arranging the inlet point in the outlet area.

[0019] There are no turbine impeller blades in the outlet area. This allows for a large pressure drop in a very simple way, enabling secondary air to be advantageously and easily guided and fed into the exhaust gas flowing through the exhaust gas branch.

[0020] To advantageously introduce secondary air, particularly from the secondary air passage flowing out through the outlet orifice and thus into the exhaust gas flowing through the exhaust gas branch, into the exhaust gas flowing through the exhaust gas branch and to advantageously mix with the exhaust gas flowing through the exhaust gas branch, a wall is provided within the turbine housing extending circumferentially, particularly along the circumference of the turbine impeller. For example, this wall can be designed to be integral with the turbine housing. This wall can be arranged, particularly downstream of the turbine impeller, such that it is arranged radially inward relative to the turbine impeller without any overlap, and thus not overlapped radially inward by the turbine impeller. Preferably, however, the wall is arranged such that it is at least partially, particularly at least primarily or completely, covered radially inward by the turbine impeller, such that it extends circumferentially along the circumference of the turbine impeller. It is conceivable that the wall is arranged downstream of at least a portion or said portion of the turbine impeller. The turbine casing wall is spaced inwardly in the radial direction of the turbine impeller from the outlet hole and in the circumferential direction of the turbine impeller. A distributor channel is formed, defined outwardly in the radial direction of the turbine impeller by the wall and inwardly in the radial direction of the turbine impeller by the wall, extending circumferentially, particularly along the circumference of the turbine impeller. The distributor channel is therefore, for example, a gap, arranged radially between the walls of the turbine impeller and thus directly defined outwardly in the radial direction of the turbine impeller and, more generally, in the radial direction of the turbine, particularly by the wall, and inwardly in the radial direction of the turbine impeller or turbine. The axial direction of the turbine impeller coincides with the axis of rotation of the impeller, wherein the radial direction of the turbine impeller extends perpendicular to the axis of rotation of the impeller. Here, the circumferential direction of the turbine impeller extends around the axis of rotation of the impeller, i.e., around the axial direction of the turbine impeller. The outlet hole opens into the distributor channel, so that secondary air flowing through the outlet hole and thus exiting the secondary air passage via the outlet hole first flows into the distributor channel. Subsequently, the secondary air can flow through the distributor channel or be guided and distributed circumferentially, especially along the circumference of the turbine impeller, via the distributor channel.

[0021] The wall has a plurality of flow holes for secondary air arranged sequentially and spaced apart from each other in the circumferential direction of the turbine impeller, allowing secondary air from the distributor passage to flow through. Preferably, the flow holes are equidistant / uniformly distributed in the circumferential direction of the turbine impeller. Each flow hole opens into the distributor passage at one end and into a region located radially inward of the turbine impeller on the inner side of the wall at the other end. In other words, this region is arranged on the side of the wall facing inward in the radial direction of the turbine impeller, opposite to the distributor passage. This means that secondary air flows from the distributor passage into and through the respective flow holes. The secondary air flowing through the respective flow holes can exit the respective flow holes and flow into the region, thus being fed into the exhaust gas flowing through that region, since the region can be traversed by the exhaust gas flow passing through the turbine casing via the exhaust gas branch. By means of a distributor channel and, consequently, by means of the walls that form or define the distributor channel, secondary air can be advantageously distributed along its circumference, particularly in the circumferential direction of the turbine impeller, so that the secondary air can be advantageously fed into and mixed with the exhaust gas. The distributor channel and walls thus form a distributor device or a component of a distributor device, wherein the distributor device is also referred to as a distributor or secondary air distributor. By means of the secondary air distributor, secondary air from the secondary air duct can be advantageously distributed and fed into the exhaust gas and, particularly, mixed with the exhaust gas, so that the exhaust gas treatment device can be heated or warmed in a short time and therefore effectively and efficiently.

[0022] It is particularly advantageous here that the outlet orifice is at least partially, especially at least primarily, and therefore more than half or completely covered by the turbine impeller radially inward. This ensures a very favorable pressure drop, especially from the supply point to the outlet orifice, so that secondary air can be advantageously fed into the exhaust gas flowing through the exhaust gas branch at least almost all of the operating range or point of the internal combustion engine.

[0023] The aforementioned end of the secondary air duct is the so-called exhaust gas branch-side end of the secondary air duct, because the secondary air duct terminates or enters the exhaust gas branch through this exhaust gas branch-side end. Here, for example, the outlet orifice is arranged at this exhaust gas branch-side end.

[0024] A particularly advantageous feature is the longitudinal region within the turbine housing that houses or extends the secondary air duct, having the exhaust gas branch-side end there. This region terminates at one of the exhaust gas branch-side ends and connects to the exhaust gas branch at that end. This means that the secondary air duct passes through the longitudinal region and thus terminates at the exhaust gas branch-side end, making the longitudinal region the end of the secondary air duct. Here, the longitudinal region is directly defined by the turbine housing, completely surrounding it circumferentially. This minimizes the number of parts required for guiding and supplying secondary air into the exhaust gas flowing through the exhaust gas branch, and consequently reduces cost, weight, and space requirements.

[0025] Preferably, the turbine housing is designed as a single piece. In other words, the turbine housing is a single housing element in which the turbine impeller is arranged at least partially, and especially at least primarily or completely. In other words, the turbine housing has a single body that, for example, completely circumferentially defines the longitudinal region of the secondary air passage. Alternatively or additionally, the body or housing element forms the aforementioned wall and preferably also forms wall portions.

[0026] Finally, it is particularly advantageous that the turbine casing, especially the main body or casing component, directly defines the receiving area, in which the turbine impeller, particularly with respect to its length extending along the turbine impeller axial direction, is at least partially, especially at least primarily, and therefore more than half or completely arranged in the receiving area, and thus in a preferably one-piece turbine casing, main body, or casing component. This thus maintains a very low number of parts and consequently low cost, structural space requirements, and costs for guiding and supplying secondary air and thus achieving secondary air injection.

[0027] The exhaust gas branch end or secondary air duct outlet is also referred to as an inlet or secondary air inlet because the secondary air duct enters the exhaust gas branch at its exhaust gas branch end or through the outlet inlet. Since the exhaust gas branch end or outlet inlet is now located within the turbine housing, the present invention specifies that the secondary air inlet be integrated into the turbine housing. The present invention particularly specifies that the aforementioned distributor be integrated into the turbine housing; preferably, the secondary air distributor is arranged downstream of at least a portion of the turbine impeller in the direction of exhaust gas flow through the turbine housing. In particular, the secondary air distributor or wall is arranged in the outlet region. The secondary air inlet or distributor is arranged, for example, immediately after the turbine impeller, so that the outlet inlet or distributor is arranged in a position that, for example, allows access to the exhaust gas branch at a point where, as low as possible, the pressure exists. In particular, it ensures that a preferred low pressure, especially a negative pressure, is always present at the end of the exhaust branch or at the inlet point, thereby preventing gases such as exhaust gas from flowing into the secondary air duct and then into the intake branch, without the need for an additional separate check valve in the secondary air duct. This allows the number of parts and consequently cost, structural space requirements, and weight to be kept very low.

[0028] Therefore, the present invention can particularly achieve the following advantages:

[0029] - Ensure a favorable pressure drop between the supply point and the access point.

[0030] - A favorable location for secondary combustion, within which, for example, the aforementioned secondary air-fuel mixture is burned, wherein this location is preferably upstream of or immediately in front of the catalytic converter, particularly in an exhaust gas treatment device.

[0031] - Secondary air injection can be implemented simply and at low cost.

[0032] The second aspect of the invention relates to a motor vehicle, preferably designed as an automobile, and especially a passenger car, having an internal combustion engine according to the first aspect of the invention. The advantages and advantageous designs of the first aspect of the invention should be regarded as advantages and advantageous designs of the second aspect of the invention, and vice versa. Attached Figure Description

[0033] Other advantages, features, and details of the invention will become apparent from the following description of preferred embodiments and in conjunction with the figures. The features and combinations of features mentioned above in the specification, as well as the features and combinations of features mentioned below in the description of the drawings and / or shown individually in the figures, may be used not only in their respective specified combinations, but also in other combinations or individually, without departing from the scope of the invention. The figures illustrate:

[0034] Figure 1 A schematic diagram of the internal combustion engine for a motor vehicle according to the present invention is shown.

[0035] Figure 2 A schematic longitudinal section view of the turbine housing of an exhaust gas turbocharger for an internal combustion engine is shown.

[0036] Figure 3 A schematic cross-sectional view of a turbine housing preferably constructed in one piece is shown.

[0037] In the figure, identical or functionally identical parts are labeled with the same reference numerals. Detailed Implementation

[0038] Figure 1 The schematic diagram shows an internal combustion engine 10 designed as a piston machine or piston engine for a motor vehicle, preferably designed as an automobile, especially a passenger car. That is, the motor vehicle, in its fully manufactured state, has an internal combustion engine 10 and can be driven by the internal combustion engine 10. The internal combustion engine 10 here has exactly four cylinders 12a-d, especially arranged in a hypothetical straight line and therefore in series or consecutively, the cylinders being formed or defined by a cylinder block 14 of the internal combustion engine 10, for example designed as a cylinder crankcase. Each cylinder 12a-d defines a respective combustion chamber 16a-d, such that the internal combustion engine 10, as Figure 1 The illustrated embodiment has exactly four combustion chambers 16a-d. Combustion occurs in the combustion chambers 16a-d during the ignition and operation of the internal combustion engine 10. Each piston is movably arranged in its respective cylinder 12a-d, wherein each piston partially defines its respective combustion chamber 16a-d.

[0039] The internal combustion engine 10 has an exhaust gas branch 18 through which exhaust gases from combustion chambers 16a-d can pass. An exhaust gas treatment device (not shown in the figure) can be arranged in the exhaust gas branch to treat the exhaust gases. During ignition, a fuel-air mixture, comprising preferably liquid fuel and fresh air, is burned during combustion in its respective combustion chambers 16a-d. The combustion of the fuel-air mixture produces exhaust gases. The internal combustion engine 10 here has an intake branch 20, also called an intake branch, through which the fresh air is directed to and enters the combustion chambers 16a-d, and thus to and into the cylinders 12a-d.

[0040] Additionally, the internal combustion engine 10 includes an exhaust gas turbocharger 22, which has a compressor 24 disposed in the intake branch 20 and a turbine 26 disposed in the exhaust gas branch 18. The compressor 24 includes a compressor impeller 28 disposed in the intake branch 20, thereby compressing the fresh air flowing through the intake branch 20. The turbine 26 includes a turbine impeller 30 disposed in the exhaust gas branch 18 and driven by exhaust gas. Furthermore, the exhaust gas turbocharger 22 includes a shaft 32 through which the compressor impeller 28 can be driven by the turbine impeller 30. By driving the compressor impeller 28, the fresh air flowing through the intake branch 20 is compressed.

[0041] In the direction of fresh air flow through the intake branch 20, a booster air cooler 34 is provided downstream of the compressor impeller 28 to cool the compressed and heated fresh air before it flows into the combustion chambers 16a-d. Additionally, in the direction of fresh air flow through the intake branch 20, a throttle valve 36 is provided downstream of the compressor impeller 28 and upstream of the booster air cooler 34 in the intake branch 20. The throttle valve 36 allows for the adjustment of the amount of fresh air supplied to the combustion chambers 16a-d.

[0042] Furthermore, the internal combustion engine 10 includes a secondary air passage 38 through which secondary air can flow, thereby allowing the secondary air flowing through the secondary air passage 38 to be supplied to the exhaust gas flowing through the exhaust gas branch 18. The secondary air supplied to the exhaust gas branch 18 or to the exhaust gas flowing through the exhaust gas branch 18 can, for example, form a secondary air-fuel mixture with the unburned and therefore still combustible components of the aforementioned fuel, wherein the fuel components are also referred to as the fuel portion. The secondary air-fuel mixture can be combusted exothermically in the exhaust gas branch 18. This allows for, for example, particularly effective and efficient heating, i.e., temperature rise of the aforementioned exhaust gas treatment device. The aforementioned fuel component contained in the exhaust gas branch 18 or in the exhaust gas flowing through the exhaust gas branch 18 is a fuel component that enters the exhaust gas branch 18 unburned from at least one of the combustion chambers 16a-d and / or is intentionally, especially in the case of bypassing all of the combustion chambers 16a-d and / or is delivered through at least one of the combustion chambers 16a-d, especially injected into the exhaust gas branch 18.

[0043] Furthermore, the internal combustion engine 10 includes a valve 40, which can regulate the amount of secondary air flowing through the secondary air passage 38. For example, the valve 40 can be switched or moved between at least one closed position and at least one open position. In the closed position, the valve 40 locks the secondary air passage 38, so no secondary air can flow through the secondary air passage 38. In the open position, the valve 40, for example, opens the secondary air passage 38, so that secondary air can flow through the secondary air passage 38 and be delivered into the exhaust gas branch 18 via the secondary air passage 38. "Delivering secondary air into the exhaust gas branch 18, i.e., into the exhaust gas flowing through the exhaust gas branch" is also referred to as secondary air injection, secondary air supply, or secondary air introduction.

[0044] To achieve a favorable secondary air injection, valve 40 is designed as a combination valve, also known as a composite valve. Through valve 40, secondary air passage 38 and intake branch 20 are connected or potentially connected at a split point A located downstream of compressor impeller 28 and upstream of throttle valve 36. This means that at split point A, at least a portion of the fresh air is diverted from intake branch 20 and can therefore be supplied or discharged. The fresh air diverted from intake branch 20 at split point A, or a portion thereof, can be supplied to secondary air passage 38 via valve 40 and, as the aforementioned secondary air, be supplied to exhaust branch 18 or to the exhaust gas flowing through exhaust branch 18. This means that the portion of fresh air diverted from intake branch 20 at split point A is the aforementioned secondary air or is used as secondary air flowing through secondary air passage 38. Because the split point A is located downstream of the compressor wheel 28, the compressor wheel 28 or compressor 24 can be used as a secondary air pump to deliver secondary air, particularly into the secondary air passage 38 and / or through the secondary air passage 38 and / or into the exhaust gas branch 18 or into the exhaust gas flowing through the exhaust gas branch 18. This avoids the need for an additional separate secondary air pump, allowing the number of parts, weight, cost, and structural space requirements of the internal combustion engine 10 to be kept very low. It can be seen that the secondary air flowing through the secondary air passage 38 originates from the intake branch 20 and is delivered into the exhaust gas flowing through the exhaust gas branch 18 after bypassing this or all of the combustion chambers 16a-d. The secondary air does not participate in combustion, at least during its path from the split point A into the exhaust gas branch 18 or into the exhaust gas flowing through the exhaust gas branch 18; therefore, it is not burned or is not used for combustion. In addition, the secondary air does not flow through any combustion chamber of the internal combustion engine 10 on its path from the split point A into the exhaust gas branch 18.

[0045] The secondary air passage 38 and valve 40 can perform dual functions. First, the secondary air passage 38 is used to supply secondary air, i.e., inject it into the exhaust gas branch 18 or supply it into the exhaust gas flowing through the exhaust gas branch 18. In this regard, valve 40 is used as a secondary air valve to regulate the amount of secondary air flowing through the secondary air passage 38 and supplied into the exhaust gas flowing through the exhaust gas branch 18. Second, the secondary air passage 38 can be said to be used to realize a schubumluft or schubumluft system, in which case valve 40 can be used as a schubumluft valve or a schubumluft system. Because the diversion point A is located downstream of the compressor impeller 28 and upstream of the throttle valve 36, for example, when the previously open throttle valve 36 is suddenly closed, it can prevent the compressor impeller 28 from being over-braked by the fresh air originally arranged between the compressor impeller 28 and the throttle valve 36 and compressed by the compressor impeller 28. That is, at least a portion of the fresh air originally arranged between the compressor impeller 28 and the throttle valve 36 is diverted from the intake branch 20 at the diversion point A and sent into the secondary air passage 38 via the valve 40.

[0046] Overview Figure 2 and 3 As can be seen, the turbine 26 has a turbine housing 42 that is preferably one-piece, i.e., integrally formed, in which the turbine impeller 30 is at least partially, especially at least mainly or completely arranged, with respect to its axial length. Here, the turbine housing 42 directly forms or defines a receiving area 44, also called a receiving space, in which the turbine impeller 30 is at least partially, especially at least mainly or completely arranged, with respect to its axial length. The turbine impeller 30 is rotatable relative to the turbine housing 42 about a rotation axis 46, also called the axis of rotation of the impeller. Here, the axial direction of the turbine impeller 30 coincides with the rotation axis 46. In the embodiment shown, the turbine housing 42 is designed as a one-piece structure. This means that the turbine housing 42 is a one-piece housing element or a one-piece body.

[0047] Furthermore, the internal combustion engine 10 has an exhaust gas bend 48, also simply referred to as a manifold, through which exhaust gases from the respective combustion chambers 16a-d are combined, or particularly, in a passage shared by the combustion chambers 16a-d. Here, the turbine housing 42 is integrated into the exhaust gas bend 48, or vice versa. This means that the exhaust gas bend 48 is designed to be integral with the turbine housing 42. The exhaust gas bend 48 has at least one exhaust gas passage 50 for each combustion chamber 16a-d, wherein the exhaust gas passages are separated from each other in their respective local areas. Exhaust gases from the combustion chambers 16a-d can flow through the exhaust gas passages 50 and be combined and, particularly, guided to the turbine housing 42. The turbine housing 42 forms or defines at least one or exactly one passage 52 through which exhaust gases from this or all of the combustion chambers 16a-d can flow, and the passage is preferably designed as a helical passage. This means that the passage 52 extends helically along the circumference of the turbine impeller 30. Exhaust gas from combustion chambers 16a-d can flow through passage 52 and is particularly guided by passage 52 to and especially into receiving area 44 and further to turbine impeller 30, i.e., passage 52 leads into receiving area 44. Here, the one-piece turbine housing 42 directly forms or defines passage 52.

[0048] To achieve secondary air injection in a particularly simple and especially cost-effective, weight-saving, and structurally space-efficient manner, the secondary air duct 38 connects to the exhaust gas branch 18 within the turbine housing 42. Here, the entry point E of the secondary air duct 38 within the turbine housing 42 is... Figure 3 The exhaust gas is introduced into the exhaust gas branch 18, wherein the inlet point E is arranged downstream of at least a portion of the turbine impeller 30 in the direction of exhaust gas flow through the turbine housing 42. It can be introduced from... Figure 2 and 3 As can be clearly seen, the inlet point E is located in the outlet region 54 of the turbine 26, through which the exhaust gas flows through the impeller blades 56 of the turbine impeller 30. Here, the outlet region 54 does not contain the impeller blades of the turbine impeller 30.

[0049] The secondary air duct 38 has at least one or exactly one outlet hole 58, which is arranged at the exhaust gas branch end E1 of the secondary air duct 38. Therefore, the secondary air duct 38 ends at the end E1 and thus at the outlet hole 58, thereby connecting the secondary air duct 38 to the exhaust gas branch 18 at or via the outlet hole and thus at the end E1. Therefore, the end E1 is arranged at the entry point E. Here, the secondary air flowing through the secondary air duct 38 can be discharged from the secondary air duct 38 via the outlet hole 58 and thus at the end E1, and thereby can be fed into the exhaust gas branch 18 and into the exhaust gas flowing through the exhaust gas branch 18. Here, the outlet hole 58 is at least partially, especially at least mainly or completely covered by the turbine impeller 30 radially inward, particularly by the following local area of ​​the turbine impeller 30, which does not have the turbine impeller blades. The radial direction of the turbine impeller... Figure 2 The double arrow 60 is indicated in the middle and extends perpendicularly to the axial direction of the turbine impeller 30.

[0050] It can be well from Figure 2 and Figure 3 As seen in the image, a wall 62 is provided within the turbine casing 42, extending circumferentially along the circumference of the turbine impeller 30. The turbine impeller extends circumferentially about the rotation axis 46 and... Figure 2 and Figure 3 Arrow 64 indicates this. In the embodiment shown, wall 62 is designed to be integral with turbine housing 42, i.e., it is constructed as a one-piece turbine housing 42, particularly a one-piece body or a one-piece housing component. Wall 62 is spaced radially inward from the outlet hole 58 of turbine impeller 30 and from the wall portion W of turbine housing 52 that connects to the outlet hole 58 circumferentially with turbine impeller 30. A distributor channel 66 is formed radially outward from wall portion W and radially inward from wall 62 of turbine impeller 30, extending circumferentially along the turbine impeller 30. The distributor channel is thus arranged radially between wall 62 and wall portion W and extends circumferentially around the turbine impeller 30, particularly completely. Here, outlet hole 58 opens into distributor channel 66, thereby allowing secondary air passage 38 to enter distributor channel 66 through its outlet hole 58.

[0051] The wall 62 has a plurality of flow holes 68 arranged sequentially and spaced apart from each other, preferably evenly / equidistantly, in the circumferential direction of the turbine impeller 30. Each flow hole opens at one end into a distributor passage 66 and at the other end into a region B, particularly arranged in the outlet region 54, which is radially arranged inside the wall 62 and can be passed through by the exhaust gas flowing through the turbine housing 42. Therefore, secondary air flowing through the secondary air passage 38 can exit the secondary air passage 38 through the outlet hole 58 and thus, or subsequently, directly flow into the distributor passage 66, as in... Figure 3As indicated by arrow 70. Secondary air flowing into distributor channel 66 can flow through distributor channel 66 and thus be guided and distributed around the circumference of turbine impeller 30 in the circumferential direction by means of distributor channel 66. Secondary air from distributor channel 66 can flow through flow passage 68, and thus flow from distributor channel 66 into region B and thereby into the exhaust gas flowing through region B via flow passage 68. Therefore, secondary air is advantageously distributed from secondary air passage 38 and fed into the exhaust gas, especially mixed with the exhaust gas. Wall 62 and distributor channel 66 thus form, for example, a secondary air distributor, by which secondary air is advantageously distributed from secondary air passage 38 along the circumference of turbine impeller 30 and can be fed into the exhaust gas.

[0052] It can be well from Figures 1 to 3 As seen in the image, the first longitudinal region L1 of the secondary air duct 38, having the exhaust gas branch end E1 of the secondary air duct 38, is arranged within the turbine housing 42 and is directly defined or formed by the turbine housing 42, i.e., a one-piece housing element or a one-piece body, completely surrounding it circumferentially. At least one second longitudinal region L2 of the secondary air duct 38 ( Figure 1 For example, it is formed or defined by a secondary air duct 74. The secondary air duct 74 is formed separately from the turbine housing 42 and is connected to the turbine housing 42, at least fluidly and preferably mechanically, that is, the second longitudinal region L2 through which secondary air can flow is connected to the longitudinal region L1. The longitudinal region L1 extends within the turbine housing 42, but the longitudinal region L2 extends entirely outside the turbine housing 42. Therefore, secondary air can flow out of the longitudinal region L2 and into the longitudinal region L1. Here, in the flow direction of the secondary air flowing through the secondary air duct 38, the longitudinal region L2 is arranged upstream of the longitudinal region L1.

[0053] The secondary air distributor, and especially the end E1 and the outlet port 58, are arranged downstream of at least a portion of the turbine impeller 30. This is because, at at least almost every operating point or state of the internal combustion engine 10, a preferred low pressure, especially a negative pressure, exists at the inlet point E and thus at the end E1 of the secondary air passage 38 (where the outlet port 58 is located). This ensures a particularly advantageous and especially preferred large pressure drop from the branch point A to the inlet point E or the end E1. Sufficient secondary air can thus be directed from the branch point A to the inlet point E without requiring excessive additional components such as actuators, pumps, and / or valves. Furthermore, unwanted backflow of exhaust gas from the inlet point E to the outlet point A can be easily prevented. In particular, check valves in the secondary air passage 38 can be avoided.

[0054] List of reference numerals

[0055] 10 Internal Combustion Engine

[0056] 12a-d cylinder

[0057] 14 Cylinder Block

[0058] 16a-d Combustion Chamber

[0059] 18 Exhaust Gas Branch Circuit

[0060] 20 Intake branch

[0061] 22 Exhaust Gas Turbocharger

[0062] 24 Compressor

[0063] 26 Turbines

[0064] 28 Compressor Wheel

[0065] 30 Turbine impeller

[0066] 32-axis

[0067] 34. Boost Air Cooler

[0068] 36 Throttle valve

[0069] 38 Secondary air passage

[0070] 40 valves

[0071] 42 Turbine casing

[0072] 44 Accommodation Area

[0073] 46 Rotation axis

[0074] 48 Exhaust Gas Bend

[0075] 50 Exhaust duct

[0076] 52 channels

[0077] 54 Export Zone

[0078] 56 Working wheel blades

[0079] 58 Outlet Hole

[0080] 60 Double Arrows

[0081] 62 wall

[0082] 64 arrows

[0083] 66 Distributor Channels

[0084] 68 flow holes

[0085] 70 arrows

[0086] 72 arrows

[0087] 74 Secondary air piping

[0088] Area B

[0089] E Access Point

[0090] E1 end

[0091] W wall

Claims

1. An internal combustion engine (10) for a motor vehicle, comprising: - An exhaust gas branch (18) through which exhaust gas from at least one combustion chamber (16a-d) of the internal combustion engine (10) passes; - An intake branch (20) through which fresh air can flow, by means of which fresh air flowing through the intake branch (20) can be directed to and introduced into the combustion chamber (16a-d); - An exhaust gas turbocharger (22) comprising a compressor (24) disposed in the intake branch (20) and having a compressor impeller (28) for compressing fresh air, and a turbine (26) disposed in the exhaust branch (18) having a turbine housing (42) and a turbine impeller (30) at least partially housed in the turbine housing (42) and driven by exhaust gas, by means of which the compressor impeller (28) can be driven; and - at least one secondary air duct (38) through which secondary air can be passed and which opens into the exhaust gas branch (18), by means of which secondary air duct the secondary air passed through the secondary air duct (38) can be fed into the exhaust gas passed through the exhaust gas branch (18), wherein The secondary air duct (38) enters the exhaust gas branch (18) within the turbine housing (42), wherein the secondary air duct (38) has at least one outlet hole (58), at which the secondary air duct (38) terminates and thus enters the exhaust gas branch (18), wherein the secondary air flowing through the secondary air duct (38) can be discharged from the secondary air duct (38) via the outlet hole (58) and thus be sent into the exhaust gas branch (18) and into the exhaust gas flowing through the exhaust gas branch (18), the outlet hole being arranged at the exhaust gas branch-side end (E1), at which the secondary air duct (38) terminates and thus enters the exhaust gas branch (18). Within the turbine housing (42), a wall (62) extending circumferentially (64) along the turbine impeller (30) is provided. This wall extends inwardly in the radial direction (60) of the turbine impeller (30) to the outlet hole (58) and is spaced apart from the wall portion (W) of the turbine housing (42) that connects to the outlet hole (58) in the circumferential direction (64) of the turbine impeller (30). Furthermore, a portion (W) is formed outwardly in the radial direction (60) of the turbine impeller (30) and inwardly in the radial direction (60) of the turbine impeller (30) by the wall (62). A distributor channel (66) is defined and extends circumferentially (64) of the turbine impeller (30), into which the outlet hole (58) opens, and wherein the wall (62) has a plurality of sequentially spaced flow holes (68) on the circumferential (64) of the turbine impeller (30), each flow hole opening at one end into the distributor channel (66) and at the other end into a region (B) arranged radially (60) of the turbine impeller (30) on the inner side of the wall (62) through which the exhaust gas flowing through the turbine housing (42) passes. Its characteristics are, - This area (B) is located in the outlet area (54) of the turbine (26), through which the working blades (56) of the turbine impeller (30) can be traversed by exhaust gas; - The outlet area (54) does not have the working blades (56) of the turbine impeller (30); - The secondary air passage (38) is located at an inlet (E) downstream of at least a portion of the turbine impeller (30) in the direction of flow of the exhaust gas flowing through the turbine housing (42) and enters the exhaust gas branch (18). - The inlet (E) is located in the outlet area (54) of the turbine (26), and the exhaust gas branch end (E1) of the secondary air duct (38) is located at the inlet; - The internal combustion engine (10) includes a valve (40) by means of which the amount of secondary air flowing through the secondary air passage (38) can be adjusted; and - Through the valve (40), the secondary air passage (38) and the intake branch (20) are connected at a split point (A) located downstream of the compressor wheel (28). Therefore, at the split point (A), at least a portion of fresh air can be diverted from the intake branch (20) and sent into the secondary air passage (38) via the valve (40), and as secondary air, it can be sent into the exhaust gas flowing through the exhaust gas branch (18) via the secondary air passage (38).

2. The internal combustion engine (10) according to claim 1, characterized in that The outlet hole (58) is at least partially covered radially (60) inward through the turbine impeller (30).

3. The internal combustion engine (10) according to claim 1 or 2, characterized in that, in The turbine housing (42) provides a longitudinal region (L1) at the exhaust gas branch end (E1) of the secondary air passage (38), the longitudinal region ends at the exhaust gas branch end (E1) and thus enters the exhaust gas branch (18), wherein the longitudinal region (L1) is directly defined by the turbine housing (42) in a circumferential manner.

4. The internal combustion engine (10) according to claim 1 or 2, characterized in that The turbine housing (42) directly defines the receiving area (44), in which the turbine impeller (30) is at least partially arranged.

5. The internal combustion engine (10) according to claim 1, characterized in that The outlet hole (58) is covered radially (60) inwardly through the turbine impeller (30) at least primarily through the turbine impeller (30).

6. The internal combustion engine (10) according to claim 4, characterized in that The turbine impeller (30) is arranged primarily in the housing area (44).

7. A motor vehicle having an internal combustion engine (10) according to any one of the preceding claims.

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