Internal combustion engine for a motor vehicle, and motor vehicle

Abstract

The invention relates to an internal combustion engine (10) for a motor vehicle, having a cylinder housing (16) which has at least two cylinders (14a, b) which partially delimit a respective combustion chamber (12a, b), having a cylinder head (30) which is formed separately from the cylinder housing (16), is connected to the cylinder housing (16) and has at least one outlet channel (22a, 24a) per cylinder (14a, b), via which outlet channel exhaust gas of the internal combustion engine (10) can be discharged from the respective cylinder (14a, b). The respective outlet channel (22a, 24a) is assigned a respective branch channel (32a, c) which runs in the cylinder head (30) and by means of which at least part of the respective exhaust gas flowing through the respective outlet channel (22a, 24a) can be branched off from the respective outlet channel (22a, 24a) and can be introduced into the respective branch channel (32a, c). A first channel (34) and a second channel (36) run in the cylinder housing (16).

Description

[0001] Internal combustion engine for a motor vehicle and motor vehicle

[0002] The invention relates to an internal combustion engine for a motor vehicle, in particular for a motor vehicle, according to the preamble of patent claim 1. Furthermore, the invention relates to a motor vehicle.

[0003] DE 10 2020 114564 A1 discloses a system having a cylinder head including an integrated exhaust manifold, and having an exhaust gas recirculation cartridge positioned in a cylindrical bore in the cylinder head at a central collection area of ​​the integrated exhaust manifold.

[0004] The object of the present invention is to provide an internal combustion engine for a motor vehicle and a motor vehicle so that a particularly advantageous operation of the internal combustion engine can be realized.

[0005] This object is achieved by an internal combustion engine having the features of patent claim 1 and by a motor vehicle having the features of patent claim 9. Advantageous embodiments with expedient further developments of the invention are specified in the remaining claims.

[0006] A first aspect of the invention relates to an internal combustion engine, also referred to as an internal combustion engine or combustion motor, for a motor vehicle, also simply referred to as a vehicle. This means that the motor vehicle, preferably designed as a motor vehicle, in particular as a passenger car, has the internal combustion engine in its fully manufactured state and can be driven by means of the internal combustion engine. In particular, the internal combustion engine is a reciprocating piston machine, thus a reciprocating piston engine. The internal combustion engine has, in particular precisely, a cylinder housing which has at least two cylinders, namely a first cylinder and a second cylinder. Thus, the respective cylinder is delimited, in particular directly, by the cylinder housing and thus formed.For example, the internal combustion engine has an output shaft designed as a crankshaft, which can be mounted on the cylinder housing so as to be rotatable about an output shaft relative to the cylinder housing. In this case, the cylinder housing is designed as a cylinder crankcase, which is also simply referred to as a crankcase. The internal combustion engine can provide drive torque for driving the motor vehicle via the output shaft. The cylinders partially delimit a respective combustion chamber. This means that a first of the combustion chambers is partially delimited by the first cylinder and a second of the combustion chambers is partially delimited by the second cylinder. During fired operation of the internal combustion engine, combustion processes take place in the respective combustion chamber and thus in the respective cylinder.During the respective combustion process, a fuel-air mixture, also referred to simply as a mixture, is combusted, in particular ignited and burned, resulting in exhaust gas from the internal combustion engine. The internal combustion engine is preferably designed as a self-igniting internal combustion engine, thus a gasoline engine. The respective mixture comprises air and a particularly liquid fuel, which is preferably a gasoline.

[0007] The internal combustion engine also has a cylinder head that is formed separately from the cylinder housing and connected to the cylinder housing. The cylinder head has, for example, at least two combustion chamber roofs, namely a first combustion chamber roof and a second combustion chamber roof. For example, the first combustion chamber is formed partially by the first combustion chamber roof and the second combustion chamber is partially by the second combustion chamber roof. Very preferably, the internal combustion engine is designed as an in-line engine, so that the cylinders, in particular their cylinder axes, are arranged successively along a straight line running in the longitudinal direction of the internal combustion engine. The longitudinal direction of the internal combustion engine coincides with the output shaft axis of rotation. The respective cylinder is designed to be at least substantially rotationally symmetrical with respect to its respective cylinder axis, also referred to as the cylinder center axis or center axis.

[0008] At least one respective exhaust port of the cylinder head is assigned to the respective cylinder and thus to the respective combustion chamber partially delimited by the respective cylinder, wherein the exhaust port assigned to the first cylinder is also referred to as the first exhaust port and the exhaust port assigned to the second cylinder is also referred to as the second exhaust port. The cylinder head therefore has at least one exhaust port per cylinder. The respective exhaust port runs in the cylinder head. The exhaust gas of the internal combustion engine can be discharged from the respective cylinder to which the respective exhaust port is assigned via the respective exhaust port. For example, the exhaust ports are components of an exhaust tract of the internal combustion engine. Very preferably, a turbine of an exhaust gas turbocharger of the internal combustion engine is arranged in the exhaust tract, wherein the turbine can be driven by the exhaust gas from the cylinders.

[0009] In order to be able to realize particularly advantageous operation of the internal combustion engine, it is provided according to the invention that at least one respective branch duct running in the cylinder head is assigned to the respective exhaust duct. The branch duct assigned to the first exhaust duct is also referred to as the first branch duct and the branch duct assigned to the second exhaust duct is also referred to as the second branch duct. By means of the respective branch duct assigned to the respective exhaust duct, a portion of the respective exhaust gas flowing through the respective exhaust duct can be branched off from the respective exhaust duct to which the respective branch duct is assigned and introduced into the respective branch duct, such that the branched exhaust gas can subsequently flow through the respective branch duct. A first duct and a second duct run in the cylinder housing.The first channel is also referred to as the first gallery, and the second channel is also referred to as the second gallery. A partition wall of the cylinder housing is arranged between respective lengths of the channels, i.e., between a first length of the first channel and a second length of the second channel, so that the partition wall separates the lengths of the channels from each other, particularly fluidically.

[0010] Furthermore, the invention provides that the first branch duct opens into the first longitudinal region, such that the exhaust gas branched off from the first branch duct by means of the first branch duct, introduced into the first branch duct, and subsequently flowing through the first branch duct can be introduced into the first longitudinal region, in particular by bypassing the second longitudinal region. This means that the exhaust gas flowing through the first branch duct does not flow into the first longitudinal region via the second longitudinal region on its way to and from the first branch duct into the first longitudinal region. The second branch duct opens into the second longitudinal region, such that the exhaust gas branched off from the second branch duct by means of the second branch duct, introduced into the second branch duct, and subsequently flowing through the second branch duct can be introduced into the second longitudinal region, in particular bypassing the first longitudinal region.This means that the exhaust gas introduced into the first branch duct and subsequently flowing through the second branch duct does not flow into the second length range via the first length range on its way from and out of the second branch duct into the second length range. The respective exhaust gas introduced from the respective branch duct into the respective length range can flow through the respective length range and subsequently through the respective duct, so that the respective duct is also referred to as the respective exhaust gas gallery.

[0011] In an advantageous embodiment, channels are fluidically connected to one another at respective points on the channels adjoining the longitudinal regions, wherein the point is also referred to as the crosstalk point. The exhaust gas flowing through the first channel can thus mix with the exhaust gas flowing through the second channel and vice versa, since the channels are fluidically connected to one another at the crosstalk points. If the channels are not fluidically connected to one another, an advantageous response behavior of the turbine, also referred to as an exhaust gas turbine, can be achieved. It is conceivable that a valve element is arranged, in particular at the point, which can be switched, for example, between an open state fluidically connecting the channels at the point and a closed state fluidically separating the channels from one another at the point.For example, the valve element can be closed in the event of dynamic acceleration, i.e. switched to the closed state, and opened in the range of high speeds and loads for a beneficial cooling effect, i.e. switched to the open state.

[0012] Compared to conventional solutions, the invention enables a reduction in the exhaust gas temperature, also known as the exhaust gas temperature. This allows an increase in the engine power of the internal combustion engine during lambda 1 operation of the internal combustion engine, i.e., during operation of the internal combustion engine with a stoichiometric combustion air ratio, without the need for excessively complex additional technologies. In other words, during operation of the internal combustion engine with a stoichiometric combustion air ratio, a particularly high power output can be achieved, i.e., a higher power output of the internal combustion engine compared to conventional solutions, so that the advantageously high power of the internal combustion engine and particularly low-emission operation of the internal combustion engine can be achieved.In other words, a particularly high specific engine power of the internal combustion engine can be achieved in lambda-I operation, i.e., when the internal combustion engine operates with a stoichiometric combustion air ratio, thus enabling particularly low-emission operation. Due to the reduction in exhaust gas temperature made possible by the invention, the maximum possible power of the internal combustion engine in lambda-I operation can be increased compared to conventional solutions, so that, for example, enrichment is no longer necessary or such enrichment can be carried out significantly later compared to conventional solutions. This ensures particularly fuel-efficient and low-emission operation of the internal combustion engine.The internal combustion engine can thus be designed as a highly charged internal combustion engine, in particular as a highly charged gasoline engine, which can have a particularly high specific power in its operation with a stoichiometric combustion air ratio.

[0013] Investigations have shown that the invention leads to the aforementioned reduction in exhaust gas temperature during the fired operation of the internal combustion engine, also referred to as internal combustion engine operation, through several effects: When an exhaust valve assigned to the respective exhaust port is opened, the exhaust gas, which flows out of the respective combustion chamber or cylinder with a high impulse, can flow through the branch channels, which are also referred to as branch channels or are designed as branch channels, and subsequently flows over the branch channels (branch channels) into the galleries (channels) in the cylinder housing.While, for example, in the turbine of a twin-scroll exhaust turbocharger, each pair of cylinders is geometrically separated from each other as closely as possible up to the turbine, thus creating a flow separation, the fluidic and thus geometric connection of the galleries and the resulting connection between the cylinders impairs the flow separation. This results in a deterioration in the turbine's efficiency, which is why, to achieve the same turbine power, a bypass channel, also known as a wastegate or wastegate channel, through which the exhaust gas bypasses the turbine, must be further closed using a corresponding valve element.This increases the mass flow of the exhaust gas driving the turbine, also known as the exhaust gas turbine, which is formed by the exhaust gas and thus also referred to as the exhaust gas mass flow. As a result, the exhaust gas temperature downstream of the turbine, also designated T4, is reduced. As a result of this reduction in the exhaust gas temperature downstream of the turbine, for example, an exhaust gas limit temperature for protecting a catalyst arranged downstream of the turbine in the exhaust tract, in particular a three-way catalyst, is only reached at a higher engine power of the internal combustion engine. This means that the specific engine power can be increased in the fired operation of the internal combustion engine with a stoichiometric combustion air ratio, also known as stoichiometric engine operation.

[0014] The exhaust gas collected in or flowing through the respective gallery can advantageously transfer heat to the cylinder housing and thus to the material surrounding the respective gallery. As a result of the high-frequency flow through the branch channels and the galleries with the exhaust gas at high speeds of the internal combustion engine, there is advantageous heat transfer between the exhaust gas and the cylinder housing, in particular such that heat is transferred from the exhaust gas to the cylinder housing. As a result, compared to conventional solutions, the exhaust gas temperature, also designated T3, drops upstream of the turbine, so that a limit temperature for engine components is only reached at higher engine power of the internal combustion engine. The previously described reduction in exhaust gas temperature has already been proven by measurements on the engine test bench.

[0015] In an advantageous embodiment of the invention, it is provided that the respective length region, i.e., its respective longitudinal extension direction, runs parallel to the longitudinal direction of the internal combustion engine and thus parallel to the output shaft rotation axis. This enables a particularly advantageous heat transfer between the respective exhaust gas flowing through the respective gallery and the cylinder housing, so that the exhaust gas temperature can be advantageously reduced compared to conventional solutions. As a result, a particularly advantageous operation of the internal combustion engine can be achieved, in particular in that a particularly high specific engine power can be achieved during stoichiometric operation.

[0016] A further embodiment is characterized in that the respective channel extends over more than half of a length of the cylinder head extending in the longitudinal direction of the internal combustion engine.

[0017] Preferably, the respective channel extends over more than 60 percent of the length of the cylinder head, whereby, for example, it is provided that the respective gallery, and thus the respective channel, extends over approximately two-thirds of the length of the cylinder head, also referred to as the total length. This ensures particularly advantageous heat transfer between the exhaust gas flowing through the respective gallery and the cylinder housing, so that the exhaust gas temperature can be reduced particularly advantageously. As a result, a particularly high specific power of the internal combustion engine can be achieved during stoichiometric engine operation.

[0018] In order to be able to reduce the exhaust gas temperature particularly advantageously, a further embodiment of the invention provides that a cooling jacket runs in the cylinder housing through which a preferably liquid cooling fluid can flow to cool the cylinder housing, wherein the respective channel is overlapped by at least one cooling channel of the cooling jacket when viewed in a direction running perpendicular to the cylinder axis of at least one of the cylinders and / or in a direction running parallel to the cylinder axis of at least one of the cylinders. As a result, for example, heat can be transferred particularly advantageously from the respective exhaust gas flowing through the respective gallery to or onto the cooling fluid flowing through the cooling channel, whereby the exhaust gas temperature can be reduced particularly effectively and efficiently.In particular, it is possible to arrange the respective gallery particularly close to the cooling jacket, in particular such that at least one of the galleries, in particular both galleries, are positioned directly next to the cooling channel in the cylinder crankcase. This results in particularly good heat transfer between the exhaust gas flowing through the respective gallery, also referred to as engine exhaust, and the cooling fluid, so that the exhaust gas temperature can be reduced particularly advantageously. Preferably, the cooling fluid is a component of the internal combustion engine. Preferably, the cooling fluid is or comprises at least or exclusively water, so that the cooling fluid is also referred to as cooling water or engine cooling water.In addition, due to the aforementioned high-frequency flow of the exhaust gas through the branch channels and the galleries at high speeds of the internal combustion engine, also known as engine speeds, an advantageous heat transfer between the engine exhaust gas and the cooling fluid can occur, so that the exhaust gas temperature can be reduced in a particularly advantageous manner.

[0019] In order to be able to realize particularly advantageous operation of the internal combustion engine, it is provided in a further embodiment of the invention that the respective branch channel is fluidically connected at a respective connection point to the respective exhaust channel to which the respective branch channel is assigned, whereby by means of the respective branch channel at least the part of the respective exhaust gas flowing through the respective exhaust channel can be branched off at the branch point from the respective exhaust channel to which the respective branch channel is assigned and introduced into the respective branch channel. In this case, the respective connection point is arranged downstream of a valve seat in the flow direction of the exhaust gas flowing through the respective exhaust channel, on which valve seat the respective exhaust valve assigned to the respective exhaust channel and designed as a gas exchange valve sits in its closed position.

[0020] In a further embodiment of the invention, the points at which the channels are fluidically connected to one another are arranged in the cylinder housing, thereby fluidically connecting the channels in the cylinder housing. This allows the exhaust gas temperature to be reduced in a particularly simple manner, thus enabling particularly advantageous operation of the internal combustion engine in a particularly simple manner.

[0021] Finally, it has proven particularly advantageous if the respective branch duct has a respective first flow cross-section through which the exhaust gas can flow, and the respective duct has a respective second flow cross-section through which the exhaust gas can flow. In particular, the respective flow cross-section is the respective smallest flow cross-section through which the exhaust gas can flow in the respective branch duct or the respective duct. In order to particularly advantageously reduce the exhaust gas temperature and consequently realize particularly advantageous operation of the internal combustion engine, it is preferably provided that the second flow cross-sections are larger than the first flow cross-sections.This means that the flow cross-sections of the galleries are designed to be large or larger relative to the flow cross-sections of the branch channels, creating a particularly large surface area for heat transfer between the exhaust gas and the cylinder housing. This allows the exhaust gas temperature to be reduced particularly advantageously.

[0022] A second aspect of the invention relates to a motor vehicle, also referred to simply as a vehicle, and preferably designed as a motor vehicle, in particular as a passenger car, which has an internal combustion engine according to the first aspect of the invention and is drivable by means of the internal combustion engine. 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.

[0023] Further advantages, features, and details of the invention will become apparent from the following description of a preferred embodiment and from the drawings. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respective combinations specified, but also in other combinations or on their own, without departing from the scope of the invention.

[0024] The drawing shows:

[0025] Fig. 1 is a schematic representation of an internal combustion engine of a motor vehicle;

[0026] Fig. 2 shows a partial schematic sectional view of the internal combustion engine; and

[0027] Fig. 3 shows a further schematic sectional view of the internal combustion engine. In the figures, identical or functionally equivalent elements are provided with the same reference numerals.

[0028] Fig. 1 shows a schematic representation of an internal combustion engine 10, also simply referred to as an internal combustion engine, combustion motor or engine, for a motor vehicle. In the exemplary embodiment shown in the figures, the internal combustion engine 10 is designed as an in-line engine and thereby as a four-cylinder in-line engine. This means that in the exemplary embodiment shown in the figures, the internal combustion engine has exactly four combustion chambers 12a-d, in which combustion processes take place during a fired operation of the internal combustion engine 10, also referred to as internal combustion engine operation. During each combustion process, a respective fuel-air mixture, also simply referred to as a mixture, is expelled, in particular ignited and burned. The respective mixture comprises fresh air, also simply referred to as air, and a preferably liquid fuel.The internal combustion engine 10 is preferably designed as a gasoline engine. The internal combustion engine 10 is most preferably designed as a supercharged internal combustion engine. The combustion of the respective mixture results in exhaust gas from the internal combustion engine 10. The internal combustion engine 10 has an exhaust tract (not shown in the figures) through which the exhaust gas from the combustion chambers 12a-d can flow. The combustion chamber 12a is also referred to as the first combustion chamber, the combustion chamber 12b as the second combustion chamber, the combustion chamber 12c as the third combustion chamber, and the combustion chamber 12d as the fourth combustion chamber.

[0029] The respective combustion chamber 12a-d is partially delimited by a respective cylinder 14a-d, in this case such that the combustion chamber 12a is partially delimited by the cylinder 14a, the combustion chamber 12b is partially delimited by the cylinder 14b, the combustion chamber 12c is partially delimited by the cylinder 14c, and the combustion chamber 12d is partially delimited by the cylinder 14d. The cylinders 14a-d are cylinders of a cylinder housing 16 of the internal combustion engine 10, so that the cylinder housing 16 delimits and thus comprises the cylinders 14a-d.

[0030] The internal combustion engine 10 has an output shaft 18, also designed as a crankshaft, which is rotatable about an output shaft rotation axis 20 relative to the cylinder housing 16. The internal combustion engine 10 can provide drive torque for driving the motor vehicle via the output shaft 18. A respective piston is accommodated in the respective cylinder 14a-d so that it can be moved in translation. The cylinder 14a is also referred to as the first cylinder, the cylinder 14b is also referred to as the second cylinder, the cylinder 14c is also referred to as the third cylinder, and the cylinder 14d is also referred to as the fourth cylinder. The pistons are articulated to the output shaft 18 via connecting rods, so that the translational movements of the pistons in the cylinders 14a-d can be converted into a rotating movement about the output shaft rotation axis 20 and relative to the cylinder housing, thus rotation of the output shaft 18.The respective piston accommodated in the respective cylinder 14a-d partially delimits the respective combustion chamber 12a-d in such a way that the piston accommodated in the cylinder 14a, also referred to as the first piston, delimits the first combustion chamber 12a, the piston accommodated in the cylinder 14b, also referred to as the second piston, the piston accommodated in the cylinder 14b, the combustion chamber 12b, also referred to as the third piston, the piston accommodated in the cylinder 14c, the combustion chamber 12c and the piston accommodated in the cylinder 14d, also referred to as the fourth piston, partially delimits the combustion chamber 12d.

[0031] The respective cylinder 14a-d and thus the respective combustion chamber 12a-d are assigned, in particular precisely, two respective exhaust ports, wherein the exhaust ports assigned to cylinder 14a are referred to as first exhaust ports, the exhaust ports assigned to cylinder 14b as second exhaust ports, the exhaust ports assigned to cylinder 14c as third exhaust ports, and the exhaust ports assigned to cylinder 14d are also referred to as fourth exhaust ports. The exhaust gas from the respective cylinder 14a-d, to which the respective exhaust ports are assigned, can be discharged via the respective exhaust ports assigned to the respective cylinder 14a-d. This means that the respective exhaust gas from the respective combustion chamber 12a-d, which is partially delimited by the respective cylinder 14a-d, can be discharged via the respective exhaust ports assigned to the respective cylinder 14a-d. The exhaust ports are, for example, components of the exhaust tract.

[0032] Fig. 2 shows, by way of example, the cylinder 14a and the combustion chamber 12a. One of the first exhaust ports associated with the cylinder 14a and thus with the combustion chamber 12a is visible in Fig. 2, with this first exhaust port being designated 22a. The previous and following explanations regarding the cylinder 14a, the combustion chamber 12a, and the exhaust port 22a can readily be applied to the other combustion chambers, cylinders, and exhaust ports, and vice versa. The exhaust ports are partially visible in Fig. 3. The first exhaust ports are designated 22a and 22b, the second exhaust ports 24a and 24b, the third exhaust ports 26a and 26b, and the fourth exhaust ports 28a and 28b.

[0033] From Figs. 2 and 3, it can be seen that the internal combustion engine 10 also has a cylinder head 30 formed separately from the cylinder housing 16, in which the exhaust ports 22a, b, 24a, b, 26a, b, and 28a, b extend, so that the cylinder head 30 has the exhaust ports 22a, b, 24a, b, 26a, b, and 28a, b. Expressed again in other words, the cylinder head 30 thus has exactly two exhaust ports 22a, b, 24a, b, 26a, b, and 28a, b for each cylinder 14a-d.

[0034] In order to be able to realize particularly advantageous operation of the internal combustion engine 10, a respective branch channel running in the cylinder head 30 is assigned to the respective exhaust channel 22a, b, 24a, b, 26a, b, and 28a, b, in particular precisely. The branch channel assigned to the exhaust channel 22a is designated 32a, the branch channel assigned to the exhaust channel 22b is designated 32b, the branch channel assigned to the exhaust channel 24a is designated 32c, the branch channel assigned to the exhaust channel 24b is designated 32d, the branch channel assigned to the exhaust channel 26a is designated 32e, the branch channel assigned to the exhaust channel 26b is designated 32f, the branch channel assigned to the exhaust channel 28a is designated 32g, and the branch channel assigned to the exhaust channel 28b is designated 32h. The branch channels 32a-h are also called branch channels.By means of the respective branch channel assigned to the respective outlet channel 22a, b, 24a, b, 26a, b, and 28a, b, at least a portion of the respective exhaust gas flowing through the respective outlet channel 22a, b, 24a, b, 26a, b, and 28a, b, to which the respective branch channel is assigned, can be branched off from the respective outlet channel 22a, b, 24a, b, 26a, b, and 28a, b, to which the respective branch channel is assigned, and introduced into the respective branch channel. The exhaust gas introduced into the respective branch channel can subsequently flow through the respective branch channel.

[0035] 2 and 3 also clearly show that a first channel 34 and a second channel 36 run through the cylinder housing 16. The channels 34 and 36 are also referred to as galleries, such that the first channel 34 is also referred to as the first gallery and the second channel 36 is also referred to as the second gallery. A partition wall T of the cylinder housing 16 is arranged between respective length regions LI and L2 of the galleries, such that the length regions LI and L2 of the galleries are fluidically separated from one another by the partition wall T. The length region LI of the first gallery is also referred to as the first length region, and the length region L2 of the second gallery is also referred to as the second length region. It can be seen that the respective length region LI, L2 extends in the longitudinal direction of the internal combustion engine 10, the longitudinal direction of which coincides with the output shaft axis of rotation 20.The partition wall T also extends in the longitudinal direction of the internal combustion engine 10, thus parallel to the longitudinal direction. Thus, the longitudinal regions LI and L2 are fluidically separated from each other by the partition wall T in a direction perpendicular to the longitudinal direction of the internal combustion engine 10.

[0036] The galleries (channels 34 and 36) are fluidically connected to each other at points S1 and S2, respectively, adjacent to the length ranges L1 and L2, so that points S1 and S2 are also referred to as crosstalk points. Point S1 is also referred to as the first point and is a point in the first gallery, and point S2 is also referred to as the second point and is a point in the second gallery.

[0037] It is particularly clearly visible in Fig. 3 that the branch channels 32a and 32b, as well as the branch channels 32e and 32f, open into the first longitudinal region LI, so that the branch channels 32a, 32b, 32e, and 32f are fluidically connected to the longitudinal region LI and thus fluidically to the first gallery. Thus, the exhaust gas flowing through the branch channels 32a, 32b, 32e, and 32f can be introduced into the longitudinal region LI and thus into the channel 34, bypassing the channel 36 and thus bypassing the longitudinal region L2. The branch channels 32c, 32d, 32g, and 32h open into the second length range L2 and thus into the second channel 36, so that the branch channels 32c, 32d, 32g, and 32h are fluidically connected to the length range L2 and thus to the second channel 36. Thus, the exhaust gas flowing through the branch channels 32c, 32d, 32g, and 32h can be introduced into the length range L2 and thus into the second channel 36, bypassing the length range L1 and thus bypassing the first channel 34.In other words, the branch channels 32a, 32b, 32e and 32f open into the length range LI, bypassing the second channel 36 and thus bypassing the second length range L2. The branch channels 32c, 32d, 32g and 32h open into the length range L2, bypassing the first channel 34 and thus bypassing the first length range LI. The exhaust gas introduced into the respective gallery can flow through the respective gallery, whereby a particularly advantageous heat transfer can take place from the respective exhaust gas flowing through the respective gallery to the cylinder housing 16. In addition, the exhaust gas flowing through the first gallery can mix with the exhaust gas flowing through the second gallery and vice versa, whereby a temperature of the exhaust gas, also referred to as the exhaust gas temperature, can be advantageously reduced.

[0038] The respective gallery is fluidically connected to the exhaust tract, for example, in particular via its respective point SI, S2 and / or via the cylinder head 30 or bypassing the cylinder head 30, so that, for example, the respective exhaust gas flowing through the respective gallery can flow out of the respective gallery and into the exhaust tract and subsequently flow through the exhaust tract. As a result, the exhaust gas can be discharged from the galleries and introduced into the exhaust tract. In particular, the respective gallery is fluidically connected to the exhaust tract, bypassing the respective branch channel, in particular to a respective transfer point, at which, for example, the respective exhaust gas flowing through the respective gallery can be discharged from the gallery and introduced into the exhaust tract.

[0039] It is particularly clearly evident from Fig. 3 that the respective gallery, in particular its respective longitudinal extension direction, runs parallel to the longitudinal direction of the internal combustion engine 10 and thus parallel to the output shaft rotation axis 20. Furthermore, the respective gallery extends over more than half, in particular over more than 60%, of a length of the cylinder head 30 extending in the longitudinal direction of the internal combustion engine 10, so that the exhaust gas can be cooled particularly advantageously and thus the exhaust gas temperature can be advantageously reduced.

[0040] From Fig. 2 it can be seen that a cooling jacket 38, also referred to as a water jacket, runs inside the cylinder housing 16 and through which a preferably liquid cooling fluid can flow to cool the cylinder housing 16. A cooling channel 40 of this cooling jacket can be seen in Fig. 2. Also visible in Fig. 2 is the cylinder 14a, the cylinder axis of which, also referred to as the central axis or cylinder central axis, is designated 42. The cylinder 14a is at least substantially rotationally symmetrical with respect to its cylinder axis 42. In the exemplary embodiment shown in the figures, the respective gallery is at least partially overlapped by the cooling channel 40 when viewed in a first direction running perpendicular to the cylinder axis 42 and, in this case, perpendicular to the longitudinal direction of the internal combustion engine 10 and illustrated by an arrow 44.Furthermore, the channel 34 is at least partially, in this case completely, overlapped by the cooling channel 40 in a second direction, illustrated by an arrow 46, running parallel to the cylinder axis 42 and perpendicular to the longitudinal direction of the internal combustion engine 10. This allows the galleries to be arranged particularly close to the cooling jacket 38, allowing the exhaust gas flowing through the galleries to be cooled effectively and efficiently.

[0041] Using the example of branch channel 32a, it can be seen in Fig. 2 that the respective branch channel is fluidically connected at a respective connection point V to the respective outlet channel 22a, b, 24a, b, 26a, b, and 28a, b, to which the respective branch channel is assigned. Thus, at least the respective portion of the exhaust gas flowing through the respective outlet channel 22a, b, 24a, b, 26a, b, and 28a, b can be branched off from the respective outlet channel 22a, b, 24a, b, 26a, b, and 28a, b at the respective connection point V and introduced into the respective branch channel. It can be seen from Fig. 2 that the respective connection point V is arranged downstream of a valve seat 48 in the flow direction of the exhaust gas flowing through the respective outlet channel 22a, b, 24a, b, 26a, b and 28a, b, on which a gas exchange valve assigned to the respective outlet channel 22a, b, 24a, b, 26a, b and 28a, b and designed as an outlet valve sits in its closed position.In addition, the galleries have larger flow cross-sections through which the exhaust gas can flow than the branch channels, allowing for particularly advantageous heat transfer from the exhaust gas to or onto the cylinder housing. This allows for particularly advantageous cooling of the exhaust gas and, consequently, a beneficial reduction in the exhaust gas temperature.

[0042] List of reference symbols

[0043] 10 Internal combustion engine 12-d Combustion chamber 14a-d Cylinder 16 Cylinder housing 18 Output shaft 20 Output shaft rotation axis 22a, b Exhaust port 24a, b Exhaust port 26a, b Exhaust port 28a, b Exhaust port 30 Cylinder head 32a-h Branch port 34 First port 36 Second port 38 Cooling jacket 40 Cooling port 42 Cylinder axis 44 Arrow 46 Arrow 48 Valve seat LI First length range L2 Second length range S1 First location S2 Second location T Partition wall V Connection point

Claims

Patent claims 1. Internal combustion engine (10) for a motor vehicle, with a cylinder housing (16) which has at least two cylinders (14a, b) which partially delimit a respective combustion chamber (12a, b), with a cylinder head (30) which is formed separately from the cylinder housing (16) and connected to the cylinder housing (16), which cylinder head has at least one exhaust channel (22a, 24a) for each cylinder (14a, b), via which exhaust gas of the internal combustion engine (10) can be discharged from the respective cylinder (14a, b), characterized in that: - a respective branch channel (32a, c) extending in the cylinder head (30) is assigned to the respective exhaust channel (22a, 24a), by means of which at least a part of the respective exhaust gas flowing through the respective exhaust channel (22a, 24a) can be branched off from the respective exhaust channel (22a, 24a) and introduced into the respective branch channel (32a, c); - a first channel (34) and a second channel (36) extend in the cylinder housing (16); - a partition wall (T) of the cylinder housing (16) is arranged between respective length regions (LI, L2) of the channels (34, 36), by means of which partition wall (T) the length regions (LI, L2) are separated from one another; and - a first of the branch channels (32a, c) opens into a first of the length regions (LI, L2) and a second of the branch channels (32a, c) opens into a second of the length regions (LI, L2).

2. Internal combustion engine (10) according to claim 1, characterized in that the respective length region (LI, L2) runs parallel to the longitudinal direction of the internal combustion engine (10).

3. Internal combustion engine (10) according to claim 1 or 2, characterized in that the respective channel (34, 36) extends over more than half of a length of the cylinder head (30) extending in the longitudinal direction of the internal combustion engine (10).

4. Internal combustion engine (10) according to claim 3, characterized in that the respective channel (34, 36) extends over more than 60% of the length of the cylinder head (30).

5. Internal combustion engine (10) according to one of the preceding claims, characterized in that a cooling jacket (38) through which a cooling fluid for cooling the cylinder housing (16) flows runs in the cylinder housing (16), wherein the respective channel (34, 36) is overlapped by at least one cooling channel (40) of the cooling jacket (38) when viewed in a direction (44) running perpendicular to a cylinder axis (42) of at least one of the cylinders (14a-d) and / or when viewed in a direction (46) running parallel to a cylinder axis (42) of at least one of the cylinders (14a-d).

6. Internal combustion engine (10) according to one of the preceding claims, characterized in that the respective branch channel (32a, c) is fluidically connected at a respective connection point (V) to the respective outlet channel (22a, 24a) to which the respective branch channel (32a, c) is assigned, whereby by means of the respective branch channel (32a, c) at least the part of the respective exhaust gas flowing through the respective outlet channel (22a, 24a) can be branched off at the connection point (V) from the respective outlet channel (22a, 24a) to which the respective branch channel (32a, c) is assigned and can be introduced into the respective branch channel (32a, c), wherein the respective connection point (V) is arranged downstream of a valve seat (48) in the flow direction of the exhaust gas flowing through the respective outlet channel (22a, 24a), on which valve seat a valve seat (48) is arranged which is assigned to the respective outlet channel (22a, 24a) and designed as an outlet valve is in its closed position.

7. Internal combustion engine (10) according to one of the preceding claims, characterized in that the points (SI, S2) at which the channels (34, 36) are fluidically connected to one another are arranged in the cylinder housing (16), whereby the channels (34, 36) in the cylinder housing (16) are fluidically connected to one another.

8. Internal combustion engine (10) according to one of the preceding claims, characterized in that the respective branch duct (32a, c) has a respective first flow cross-section through which the exhaust gas can flow and the respective duct (34, 36) has a respective second flow cross-section through which the exhaust gas can flow, wherein the second flow cross-sections are larger than the first flow cross-sections.

9. Motor vehicle with an internal combustion engine (10) according to one of the preceding claims, wherein the motor vehicle can be driven by means of the internal combustion engine (10).

Images