DE102016006146B3 - Drive device and method for operating a drive device - Google Patents

Abstract

The invention relates to a drive device (1) with an internal combustion engine (2), which has a cylinder head (9) and a first exhaust manifold (7) and a second exhaust manifold (8). It is provided that the first exhaust manifold (7) provided with a heat insulation (12) and the second exhaust manifold (8) for temperature control is associated with a temperature control device (10), wherein the first exhaust manifold (7) and the second exhaust manifold (8) from each other have different flow areas. The invention further relates to a method for operating a drive device (1).

Description

The invention relates to a drive device with an internal combustion engine, with the features of the preamble of claim 1. The invention further relates to a method for operating a drive device having the features of the preamble of claim 5.

The internal combustion engine serves to provide a torque, which is directed, for example, to a driving of the motor vehicle. In this case, insofar as the motor vehicle on the internal combustion engine. The internal combustion engine has at least one cylinder, in which a piston is arranged longitudinally movable. Preferably, the cylinder is present at least partially in a cylinder crankcase of the internal combustion engine and is limited in one direction, in particular in geodetic direction upward, of the cylinder head. The cylinder head is arranged for this purpose on the cylinder crankcase or attached thereto.

During operation of the internal combustion engine, exhaust gas accumulates, which has to be removed from the cylinder, in particular in the direction of an external environment of the internal combustion engine. For this purpose, the first exhaust manifold and the second exhaust manifold are provided. These are fluidically connected to the cylinder, wherein a flow connection between the cylinder and the first exhaust manifold extends, for example via a first exhaust valve and a flow connection between the cylinders and the second exhaust manifold, for example via a second exhaust valve. Particularly preferably, the internal combustion engine has a plurality of cylinders which each have at least one first outlet valve and at least one second outlet valve.

Both the first exhaust manifold and the second exhaust manifold are preferably fluidly connected to each of the plurality of cylinders, wherein the flow connection for the first exhaust manifold extends over the first exhaust valves of the cylinders and for the second exhaust manifold over the second exhaust valves of the cylinders. Each of the exhaust valves may be in at least two states, wherein in a first of the states the flow communication between the respective cylinder and the respective exhaust manifold is interrupted and in a second of the states at least partially, in particular completely, is enabled.

In particular, when the internal combustion engine is assigned an exhaust gas aftertreatment device and / or an exhaust gas turbocharger, certain requirements are made of the exhaust gas temperature of the exhaust gas produced by the internal combustion engine. For example, it is advantageous if the exhaust aftertreatment device is brought to its operating temperature as quickly as possible by means of a high exhaust gas temperature. On the other hand, the exhaust gas temperature must be less than a certain maximum temperature in order to reliably avoid damage to the exhaust gas aftertreatment device and / or the exhaust gas turbocharger.

From the prior art, for example, the publication DE 10 2015 007 974 B3 known. This describes a drive device with an internal combustion engine having a cylinder head and a first exhaust manifold and a second exhaust manifold. It is provided that the first exhaust manifold is cooled at least partially weaker than the second exhaust manifold.

The publication DE 43 44 277 A1 describes an internal combustion engine which has at least two cam-operated, on and off exhaust valves per cylinder. A first outlet channel leads to a starting catalyst close to the engine, a second outlet channel switched off during the warm-up phase leads to a main catalytic converter, bypassing the starting catalyst. When the main catalytic converter is warm, all the exhaust valves are switched on in a lower and middle load range of the internal combustion engine, while in the upper load range, the exhaust duct leading to the starting catalytic converter is switched off. By appropriately designing the control cam actuating the exhaust ports, the exhaust valve of the first exhaust port closes and opens earlier than that of the second exhaust port.

Furthermore, the document is from the prior art DE 41 27 596 A1 known. This shows a device for the catalytic purification of the exhaust gases of an internal combustion engine with two all combustion chambers of the engine exhaust side downstream catalyst arrangements with secondary air supply, one of which is designed for exhaust gas purification with cold engine and close to the machine, while designed for exhaust purification with maximum engine power second catalyst arrangement maschinenfern in Row with the first catalyst assembly is arranged in an exhaust pipe, and controlled in dependence on a temperature in the region of the first catalyst arrangement valves for direct exhaust gas supply to the second catalyst arrangement while at least largely bypassing the first catalyst assembly at high values of this temperature. It is provided that all combustion chambers of the engine are two exhaust manifolds in common, which are acted upon by the valves optionally with exhaust gas, of which a first exhaust manifold only feeds the first catalyst assembly, while of the second exhaust manifold, the exhaust pipe goes off and both are provided with independently controllable secondary air supplies for oxidizing operation of the catalyst containing three-way catalysts.

Furthermore, from the document DE 10 2012 004 954 A1 Exhaust manifold for an internal combustion engine, from the document DE 103 01 438 A1 an exhaust manifold, from the publication DE 103 31 938 A1 a motor vehicle with an exhaust gas cooling system, from the publication DE 20 2015 101 924 U1 a exhaust-gas-charged internal combustion engine with at least two turbines and switchable outlet openings and from the document DE 10 2006 048 613 A1 an exhaust system known.

It is an object of the invention to propose a drive device which has advantages over known drive devices, in particular with regard to the exhaust system and the exhaust gas temperature control.

This is achieved according to the invention with a drive device having the features of claim 1. It is provided that the second exhaust manifold for temperature control is associated with a temperature control, and that the first exhaust manifold outside of the cylinder head and the second exhaust manifold is present within the cylinder head.

As seen in the direction of flow of the exhaust gas, the first exhaust manifold and / or the second exhaust manifold begin immediately at the exhaust valves connected to it or, alternatively, at connecting lines extending from the exhaust valves connected to the exhaust manifold to the respective exhaust manifold. Further seen in the flow direction of the respective exhaust manifold extends to a point which downstream, in particular immediately downstream, the most downstream exhaust valve or the most downstream, which opens into the exhaust manifold connecting line.

Preferably, therefore, exhaust valves of all cylinders of the internal combustion engine or connection lines connected to them respectively open into either the first exhaust manifold or the second exhaust manifold. If the exhaust manifolds are in each case connected to all cylinders of the internal combustion engine, then they respectively serve to bring together exhaust gas of all cylinders of the internal combustion engine.

It is now envisaged that the first exhaust manifold is provided with the thermal insulation. On the other hand, the tempering device is associated with the second exhaust manifold, by means of which it can be actively tempered, in particular actively cooled. The temperature control is, for example, in the form of a cooling jacket, which is associated with the second exhaust manifold, in particular this surrounds at least partially. The cooling jacket is preferably in heat transfer communication with the second exhaust manifold.

The two exhaust manifolds should now have different flow cross-sections. This is to be understood, for example, that the smallest throughflow cross section of the first exhaust manifold present in the flow direction of the exhaust gas over the entire first exhaust manifold differs from the smallest flow cross section of the second exhaust manifold present in the flow direction over the entire second exhaust manifold. In other words, the first exhaust manifold has a pressure loss that is different from the pressure loss of the second exhaust manifold.

Due to the different flow cross-sections, the amount of exhaust gas flowing through the exhaust manifold can be adjusted to the desired values, in particular the ratio of the exhaust gas mass flows flowing through the exhaust manifold to each other. Because the downstream of the first exhaust manifold from this exiting exhaust gas due to the heat insulation is warmer than the exhaust gas flowing through the second exhaust manifold, which is tempered by the tempering or can be, by the appropriate choice of the flow cross-sections, the temperature of the exhaust gas downstream of the two exhaust manifold, which is composed of the exhaust gas flowing through the first exhaust manifold and the exhaust gas flowing through the second exhaust manifold can be adjusted.

In addition, it is provided that the first exhaust manifold, in particular an exhaust manifold of the first exhaust manifold, outside of the cylinder head and the second exhaust manifold, in particular an exhaust manifold of the second exhaust manifold, is present within the cylinder head. The first exhaust manifold is thus at least partially, in particular completely, outside the cylinder head. The second exhaust manifold, however, runs completely within the cylinder head and is thereby formed for example by the cylinder head. Generally speaking, the second exhaust manifold has a flow path that extends over a longer distance in the cylinder head than the flow path of the first exhaust manifold. Alternatively, this is present in the cylinder head or embraced by the cylinder head Flow volume of the second exhaust manifold is greater than that of the first exhaust manifold.

Specifically, at least the exhaust manifold of the first exhaust manifold, into which the exhaust gas of all cylinders connected to the first exhaust manifold is introduced, is outside of the cylinder head, preferably completely outside the cylinder head. The exhaust manifold of the second exhaust manifold, in which the exhaust gas is introduced all connected to the second exhaust manifold cylinder, however, is disposed within, in particular completely within, the cylinder head. To that extent, different exhaust gas temperatures can form in the first exhaust manifold and the second exhaust manifold, in particular because the second exhaust manifold is temperature-controlled, namely with the aid of the temperature control device.

In a further embodiment of the invention, it is provided that the first exhaust manifold is present as a separate component of the cylinder head and / or the second exhaust manifold is integrated into the cylinder head. The first exhaust manifold is so far not formed integrally with the cylinder head, but is attached to the cylinder head during assembly of the internal combustion engine or fluidly connected to the cylinder and / or the exhaust valves. The first exhaust manifold has, for example, at least one pipe or exhaust manifold, which extends outside of the cylinder head. While of course the second exhaust manifold may also be configured as a separate component, which is now arranged within the cylinder head, it should preferably be integrated into the cylinder head. This means that a pipeline of the second exhaust manifold, in particular the exhaust manifold, is formed by the cylinder head.

The second exhaust manifold is so far preferably formed directly in the production of the cylinder head with.

In a further preferred embodiment of the invention, it is provided that the first exhaust manifold is fluidly connected to first exhaust valves of cylinders of the internal combustion engine and the second exhaust manifold to second exhaust valves of the cylinder. On such a configuration has already been mentioned above. The internal combustion engine may have a plurality of cylinders, the cylinder or the cylinders each having at least one first exhaust valve and at least one second exhaust valve. Of course, each of the cylinders may have a plurality of first exhaust valves and / or a plurality of second exhaust valves. The first exhaust valve or all the first exhaust valves are now fluidly connected to the first exhaust manifold, while the second exhaust valve, in particular all second exhaust valves, are fluidically connected to the second exhaust manifold.

A development of the invention provides that the first exhaust valves and / or the second exhaust valves can be actuated by means of a variable valve control. Preferably, it is provided that the exhaust gas of the cylinder of the internal combustion engine is divided between the first exhaust manifold and the second exhaust manifold, so that each of the exhaust manifold is flowed through by a desired exhaust gas mass flow. This splitting may be realized, for example, by means of the variable valve control, which may be associated with the first exhaust valves, the second exhaust valves, or both the first exhaust valves and the second exhaust valves. Those exhaust valves which can not be actuated via the variable valve control are actuated via a conventional valve control with constant control times.

In a preferred further embodiment of the invention it is provided that the first exhaust manifold opens into a first exhaust pipe and the second exhaust manifold into a second exhaust pipe, wherein the first exhaust pipe and the second exhaust pipe open at a discharge point in a common exhaust pipe. The first exhaust manifold is so far fluidly provided between the first exhaust valves and the first exhaust pipe and analogous to the second exhaust manifold between the second exhaust valves and the second exhaust pipe. It should be noted in this case that the respective exhaust pipe begins only downstream of the respective exhaust manifold, so only after the merging of the exhaust gas of the cylinder connected to the respective exhaust manifold.

The combined by means of the first exhaust manifold exhaust gas and the combined with the aid of the second exhaust manifold exhaust gas are combined at the confluence point in the common exhaust pipe. For this purpose, the first exhaust pipe and the second exhaust pipe open into this or unite in this. The combined exhaust gas in the common exhaust line in this case has an exhaust gas temperature, which results in dependence on the exhaust gas flowing through the exhaust gas mass flows from the temperature of the exhaust gas of the first exhaust manifold and the exhaust gas of the second exhaust manifold.

A further embodiment of the invention provides that downstream of the discharge point, an exhaust gas turbocharger and / or at least one Exhaust after-treatment device are arranged in the common exhaust pipe / is. After merging the exhaust gas, the entire exhaust gas of the internal combustion engine can flow through the exhaust gas turbocharger and / or the exhaust gas aftertreatment device. Preferably, the exhaust gas turbocharger is fluidically between the discharge point and the exhaust gas aftertreatment device or - in the case of several exhaust aftertreatment devices - between the discharge point and all exhaust aftertreatment devices.

The exhaust aftertreatment device can be designed, for example, as a catalyst or as a particle filter. The catalyst is present in particular in the form of an SCR catalyst, an oxidation catalyst or a barrier catalyst. The catalyst may be integrated in the particulate filter, the latter being preferably designed as a diesel particulate filter. If a plurality of exhaust aftertreatment devices are present, the exhaust gas aftertreatment device following in the direction of flow to the discharge point or the exhaust gas turbocharger is preferably designed as a diesel particulate filter, SCR catalytic converter and / or as an SCR catalytic converter integrated in the diesel particulate filter. The further downstream exhaust gas aftertreatment device is present, for example, as a barrier catalytic converter, in particular with an SCR coating, or as a diesel oxidation catalytic converter.

A further embodiment of the invention provides that the first exhaust manifold is in heat transfer connection with a cylinder head cooling of the internal combustion engine that represents the tempering device. This has already been pointed out above. The tempering or cylinder head cooling can be realized by means of the aforementioned water jacket.

A development of the invention provides that the flow cross-section of the first exhaust manifold is smaller than the flow cross-section of the second exhaust manifold. With such an embodiment, it is possible to ensure that, on the one hand, the exhaust gas aftertreatment can be rapidly heated with the aid of the exhaust gas flowing through the first exhaust manifold, but, on the other hand, overheating of the exhaust gas aftertreatment device and / or the exhaust gas turbocharger can be avoided reliably. Due to the specific choice of the flow cross sections, a larger proportion of the exhaust gas can always flow through the second exhaust manifold than the first exhaust manifold, if exhaust gas is supplied to both exhaust manifolds of the internal combustion engine. Especially at full load of the internal combustion engine, the greater part of the exhaust gas is cooled sufficiently strong and only a small portion of the exhaust gas discharged at a higher temperature.

A further preferred embodiment of the invention provides that in the first exhaust pipe, a first Querschnittsverstellelement and / or in the second exhaust pipe, a second Querschnittsverstellelement is arranged. It has already been explained above that the splitting of the exhaust gas into the first exhaust manifold and the second exhaust manifold can be realized by means of the variable valve control. Additionally or alternatively, however, the first Querschnittsverstellelement, the second Querschnittsverstellelement or both the first Querschnittsverstellelement and the second Querschnittsverstellelement be provided. These may additionally or alternatively be used to split the exhaust gas to the first exhaust manifold and the second exhaust manifold.

The invention further relates to a method for operating a drive device, in particular a drive device according to the preceding embodiments, wherein the drive device has an internal combustion engine having a cylinder head and a first exhaust manifold and a second exhaust manifold. It is provided that the first exhaust manifold is provided with a thermal insulation and the second exhaust manifold for temperature control is associated with a temperature control, wherein the first exhaust manifold and the second exhaust manifold having different flow cross-sections, and wherein the greater part of the exhaust gas generated by the internal combustion engine in a first Operating mode is supplied to the first exhaust manifold and in a second mode to the second exhaust manifold.

The advantages of such an approach or such an embodiment of the drive device has already been pointed out. Both the drive device and the method can be developed according to the above statements, so that reference is made to this extent.

In the context of the method, it may be provided that the exhaust gas of the internal combustion engine is divided between the first exhaust manifold and the second exhaust manifold, so that in the first exhaust manifold a certain first exhaust gas temperature and in the second exhaust manifold a certain second exhaust gas temperature is present. The exhaust gas temperatures are selected in particular such that in a common exhaust pipe, in which the exhaust gas flows from both the first exhaust manifold and from the second exhaust manifold, assumes a certain value. Preferably, the first exhaust manifold is isolated while the second exhaust manifold is cooled.

As long as the temperature of an exhaust gas aftertreatment device is lower than an operating temperature, a larger exhaust gas mass flow is supplied to the first exhaust gas manifold than to the second exhaust gas manifold, so that the exhaust gas aftertreatment device is heated up rapidly. Additionally or alternatively, the exhaust gas mass flows in the first exhaust pipe and / or the second exhaust pipe are adjusted such that the exhaust gas temperature in the common exhaust pipe is less than or equal to a preset temperature, which corresponds for example to a maximum temperature of an exhaust gas turbocharger arranged in the common exhaust pipe. Thus, a temperature-induced damage to the exhaust gas turbocharger is effectively prevented.

For example, it is thus provided that for heating the exhaust aftertreatment device, the first exhaust manifold is acted upon by a larger exhaust gas mass flow than the second exhaust manifold, in particular only the first exhaust manifold is subjected to exhaust gas. If, on the other hand, the exhaust-gas temperature in the common exhaust gas line is to be lowered, preferably at full load of the internal combustion engine, then at least part of the exhaust gas is passed through the second exhaust manifold, in particular only exhaust gas is applied to the second exhaust manifold.

The invention will be explained in more detail with reference to the embodiments illustrated in the drawings, without any limitation of the invention. The single figure shows a schematic representation of a drive device.

The figure shows a schematic representation of a drive device 1 with an internal combustion engine 2 and an exhaust system 3 , About the exhaust system 3 becomes exhaust gas of the internal combustion engine 2 discharged, in particular in the direction of an external environment of the drive device 1 , The internal combustion engine 2 has any number of cylinders 4 on; in the embodiment shown here are three cylinders 4 intended.

Each of the cylinders 4 has a first exhaust valve 5 as well as a second exhaust valve 6 , In the illustrated embodiment, the first exhaust valves 5 and the second exhaust valves 6 operated by means of a variable valve control.

To the first exhaust valves 5 is a first exhaust manifold 7 fluidly connected while to the second exhaust valves 6 a second exhaust manifold 8th fluidically connected. It becomes clear that the first exhaust manifold 7 at least partially outside of a cylinder head 9 the internal combustion engine 2 runs while the second exhaust manifold 8th inside the cylinder head 9 is present, in particular integrated in these. By such an embodiment of the internal combustion engine 2 is generally stated that the first exhaust manifold 7 cooled less than the second exhaust manifold 8th , Particularly preferred is the second exhaust manifold 8th a cooling jacket 10 of the cylinder head 9 assigned, by means of which it is actively coolable. The cooling jacket 10 provides a tempering device for the second exhaust manifold so far 8th dar. The cooling jacket 10 becomes, for example, in the direction of the arrows 11 flows through coolant. The first exhaust manifold 7 on the other hand is preferably at least partially, in particular completely not or at best passively coolable. At least regionally, the first exhaust manifold 7 with a thermal insulation 12 Mistake.

To the first exhaust manifold 7 is a first exhaust pipe 13 connected while to the second exhaust manifold 8th a second exhaust pipe 14 connected. The exhaust pipes 13 and 14 lead to a confluence point 15 in a common exhaust pipe 16 one. In the first exhaust pipe 13 may be provided an exhaust aftertreatment device, which so far upstream of the confluence 15 is present. Downstream of the confluence 15 can in the common exhaust pipe 16 an exhaust gas turbocharger 17 or its turbine 18 be provided fluidically. Additionally or alternatively, downstream of the confluence 15 at least one exhaust aftertreatment device 19 in the exhaust pipe 16 in front.

It is envisaged that the first exhaust manifold 7 and the second exhaust manifold 8th Have different flow cross sections, in particular the flow cross section of the first exhaust manifold 7 is smaller than the flow cross section of the second exhaust manifold 8th , In this way, a particularly efficient temperature control of the exhaust gas downstream of the exhaust manifold 7 and 8th , in particular downstream of the mouth 15 reached.

Claims (5)

Drive device ( 1 ) with an internal combustion engine ( 2 ), which has a cylinder head ( 9 ) and a first exhaust manifold ( 7 ) and a second exhaust manifold ( 8th ), wherein the first exhaust manifold ( 7 ) and the second exhaust manifold ( 8th ) have different flow cross-sections and the first exhaust manifold ( 7 ) with a thermal insulation ( 12 ), characterized in that the second exhaust manifold ( 8th ) for tempering a tempering device ( 10 ), and that the first exhaust manifold ( 7 ) outside of the cylinder head ( 9 ) and the second Exhaust manifold ( 8th ) within the cylinder head ( 9 ) is present. Drive device according to claim 1, characterized in that the first exhaust manifold ( 7 ) with a tempering device ( 10 ) performing cylinder head cooling of the internal combustion engine ( 2 ) is in heat transfer connection. Drive device according to one of the preceding claims, characterized in that the first exhaust manifold ( 7 ) in a first exhaust pipe ( 13 ) and the second exhaust manifold ( 8th ) in a second exhaust pipe ( 14 ), wherein the first exhaust pipe ( 13 ) and the second exhaust pipe ( 14 ) on an outside of the cylinder head ( 9 ) arranged discharge point ( 15 ) in a common exhaust pipe ( 16 ). Drive device according to one of the preceding claims, characterized in that the flow cross-section of the first exhaust manifold ( 7 ) is smaller than the flow cross-section of the second exhaust manifold ( 8th ). Method for operating a drive device ( 1 ), in particular a drive device ( 1 ) according to one or more of the preceding claims, wherein the drive device ( 1 ) via an internal combustion engine ( 2 ), which has a cylinder head ( 9 ) and a first exhaust manifold ( 7 ) and a second exhaust manifold ( 8th ), wherein the first exhaust manifold ( 7 ) and the second exhaust manifold ( 8th ) have different flow cross-sections and the first exhaust manifold ( 7 ) with a thermal insulation ( 12 ), characterized in that the second exhaust manifold ( 8th ) for tempering a tempering device ( 10 ), and that the first exhaust manifold ( 7 ) outside of the cylinder head ( 9 ) and the second exhaust manifold ( 8th ) within the cylinder head ( 9 ) is present, wherein the greater part of the of the internal combustion engine ( 2 ) generated in a first mode of the first exhaust manifold ( 7 ) and in a second mode the second exhaust manifold ( 8th ) is supplied.

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