EP3850205A1

EP3850205A1 - Method for operating an internal combustion engine

Info

Publication number: EP3850205A1
Application number: EP19765707.5A
Authority: EP
Inventors: Thomas Malischewski
Original assignee: MAN Truck and Bus SE
Current assignee: MAN Truck and Bus SE
Priority date: 2018-09-13
Filing date: 2019-09-06
Publication date: 2021-07-21
Also published as: BR112021004456A2; DE102018122342A1; CN112689705A; WO2020053081A1; US20210189979A1; US11732660B2

Abstract

The invention relates to a method for operating an internal combustion engine (10). The method includes generating a pressure pulse in an exhaust gas system (24) of the internal combustion engine (10). The method also includes supplying exhaust gas from a combustion chamber (16) of a cylinder (12) during an exhaust outlet stroke of the cylinder (12) into an inlet channel (14) of the cylinder (12) by propagating the pressure pulse from the exhaust gas system (24) into the combustion chamber (16) fo of the cylinder (12). The method further includes supplying the exhaust gas from the inlet channel (14) of the cylinder (12) into the combustion chamber (16) of the cylinder (12) during an intake stroke of the cylinder (12). By means of internal residual gas control (residucal exhaust gas control), the method permits the exhaust gas temperature to be raised in at low load without negatively influencing the full-load performance of the internal combustion engine (10).

Description

Method for operating an internal combustion engine

description

The invention relates to a method for operating an internal combustion engine.

In order to increase the nitrogen oxide conversion rates of an SCR catalytic converter, in particular under low load of an internal combustion engine, it may be necessary, for example, to increase an exhaust gas temperature.

Conventionally, the residual gas rate can be influenced in the low load via the valve overlap. However, this deepens the valve pockets in the piston, which in turn are relevant to consumption. In order to carry out internal exhaust gas recirculation in the combustion chamber of a diesel engine, AT 005 783 U1 discloses that the intake valve is opened briefly during the exhaust cycle. In order to achieve an improvement in emissions on the one hand in the low engine speed range and on the other hand in the medium and high engine speed range, provision is made for the beginning of the intake valve advance stroke in the range from 180 ° to 210 ° crank angle (KW) after the top dead center of the ignition he follows.

US 2009/0194080 A1 relates to a method for purging residual combustion gas from an internal combustion engine with direct injection, in particular a diesel engine. When the engine is running at low speeds and high load conditions, during a sequence of opening / closing exhaust valves during the exhaust phase of the engine, at least one opening / closing sequence of intake valves is performed to purge the remaining burned gas.

The invention is based on the object of providing a method in which the exhaust gas temperature can be raised under low load.

The object is achieved by the features of independent claim 1. Advantageous further developments are specified in the dependent claims and the description.

The invention relates to a method for operating an internal combustion engine (z. B. four-stroke internal combustion engine and / or multi-cylinder internal combustion engine). The method involves generating a pressure pulse (eg significant and / or sudden and / or time-limited and / or one-time pressure increase, eg a cyclical pressure pulsation, for example) an exhaust line of the internal combustion engine. The method comprises supplying exhaust gas (eg residual exhaust gas) from a combustion chamber of a cylinder during an exhaust stroke of the cylinder into an inlet channel of the cylinder by spreading the pressure pulse from the exhaust gas line into the combustion chamber of the cylinder. The method comprises supplying the exhaust gas from the inlet channel of the cylinder into the combustion chamber of the cylinder during an intake stroke of the cylinder.

The process enables the exhaust gas temperature to be increased in the low load by means of internal residual gas control (residual exhaust gas control) without negatively influencing the full load performance of the internal combustion engine. This increases the possible nitrogen oxide conversion rates of an SCR catalytic converter. The method uses the pressure pulsations in the exhaust system to convey residual gas from the combustion chamber into an intake tract of the internal combustion engine. The residual gas is then flushed back into the combustion chamber of the cylinder in the intake stroke, whereby the mass of fresh air in the combustion chamber of the cylinder is reduced by the mass of the residual gas. Due to the reduced air and therefore also exhaust gas mass flow, the exhaust gas temperature rises with the engine torque remaining unchanged, without negatively influencing the engine's gas exchange work.

In one embodiment, the pressure pulse in the exhaust line is generated by opening an exhaust valve of a further cylinder of the internal combustion engine during an exhaust stroke of the further cylinder.

In a further exemplary embodiment, the further cylinder is operated out of phase with the cylinder, preferably out of phase by approximately -120 ° KW (eg in the case of a six-cylinder internal combustion engine) and / or by -720 ° KW / number of cylinders of the internal combustion engine.

The pressure pulse can expediently be conducted, for example, via an exhaust gas turbine, e.g. B. from an exhaust manifold via the exhaust gas turbine to another exhaust manifold.

For example, the exhaust line can be single-flow, i.e. H. with an exhaust manifold, or multi-flow, d. H. be equipped with several exhaust manifolds.

In one embodiment, the supply of exhaust gas from the combustion chamber of the cylinder is only brought about by an increase in a cylinder pressure in the combustion chamber of the cylinder by the pressure pulse. The cylinder pressure can preferably be increased via a boost pressure in the inlet channel of the cylinder and / or the internal combustion engine. In a further embodiment, the pressure pulse propagates through an (e.g. already previously) opened exhaust valve of the cylinder, preferably during an exhaust stroke of the cylinder, from the exhaust gas line into the combustion chamber of the cylinder.

In one embodiment variant, exhaust gas is fed from the combustion chamber of the cylinder into the inlet channel of the cylinder by the pressure pulse by opening an inlet valve of the cylinder, preferably during an exhaust stroke of the cylinder and / or during the pressure pulse.

In a further embodiment variant, the exhaust gas is fed from the inlet channel of the cylinder into the combustion chamber of the cylinder during an intake stroke of the cylinder by opening an inlet valve of the cylinder.

In one exemplary embodiment, the inlet valve of the cylinder only opens when the pressure pulse propagates into the combustion chamber of the cylinder. As an alternative or in addition, the inlet valve of the cylinder only opens when the cylinder pressure in the combustion chamber of the cylinder increases due to the pressure pulse via a boost pressure in the inlet channel of the cylinder and / or the internal combustion engine.

In a further exemplary embodiment, the inlet valve of the cylinder closes if or before the cylinder pressure in the combustion chamber of the cylinder again drops below a boost pressure in the inlet channel of the cylinder and / or the internal combustion engine.

In one embodiment, the inlet valve of the cylinder opens at the beginning of the outlet stroke of the further cylinder and / or the inlet valve of the cylinder opens when the outlet valve of the further cylinder opens. Alternatively or additionally, the intake valve of the cylinder opens in the exhaust stroke of the cylinder and / or closes before the end of the exhaust stroke of the cylinder.

In a further embodiment, the inlet valve of the cylinder is in a range between 100 ° KW after UT (bottom dead center of a piston movement of a piston which is assigned to the cylinder) in the working cycle of the cylinder and 150 ° KW nach UT (bottom dead center of the piston movement of the Piston, which is assigned to the cylinder) open in the exhaust stroke of the cylinder.

In one embodiment variant, the inlet valve of the cylinder opens at approximately or after 100 ° KW after UT (bottom dead center of a piston movement of a piston that the cylinder is assigned) in the exhaust stroke of the cylinder, and / or the inlet valve of the cylinder closes at approximately or before 150 ° CA after UT (bottom dead center of a piston movement of a piston which is assigned to the cylinder) in the exhaust stroke of the cylinder.

In a further embodiment variant, the intake valve of the cylinder is open for approximately or less than 50 ° KW in the exhaust stroke of the cylinder.

In one embodiment, a maximum stroke of the intake valve of the cylinder during the exhaust stroke of the cylinder is smaller than a maximum stroke of the intake valve of the cylinder during an intake stroke of the cylinder.

In a further exemplary embodiment, a maximum stroke of the intake valve of the cylinder during the exhaust stroke of the cylinder is less than 1/3 or less than 1/4 of a maximum stroke of the intake valve of the cylinder during an intake stroke of the cylinder.

In a further exemplary embodiment, a maximum stroke of the intake valve of the cylinder during the exhaust stroke of the cylinder is less than 3 mm, preferably between 1 mm and 2 mm. For example, a maximum stroke of the intake valve of the cylinder during the intake stroke of the cylinder can be around 10 mm.

In one embodiment, a valve control curve of the intake valve of the cylinder is invariable and / or a valve control curve of the intake valve of the cylinder is brought about by a non-switchable and / or rigid cam of a camshaft of the internal combustion engine.

In a further embodiment, an actuating device, preferably a valve, is rigid and / or non-switchable for actuating the inlet valve of the cylinder. Alternatively or additionally, a valve control curve of the intake valve of the cylinder is under low load of the internal combustion engine, such as under medium load and / or under full load of the internal combustion engine.

In an embodiment variant, the method further comprises operating the internal combustion engine under low load during the generation of the pressure pulse, the supply of exhaust gas from the combustion chamber and / or the supply of the exhaust gas from the inlet duct.

In a further embodiment variant, the method furthermore operates the internal combustion engine in a range up to 30%, up to 35% and / or up to 40% load (partial load or% of a nominal load of the internal combustion engine) and / or in a low speed range, preferably as between 800 U / min and 1400 U / min, during the generation of the pressure pulse, the Supplying exhaust gas from the combustion chamber and / or supplying the exhaust gas from the inlet duct.

In one exemplary embodiment, the method for increasing an exhaust gas temperature in the exhaust line, preferably under low load of the internal combustion engine, is carried out, preferably for increasing a conversion rate of an SCR catalytic converter in the exhaust line.

In a further exemplary embodiment, the internal combustion engine has a plurality of cylinders (for example 4, 6, 8, 10, 12 or more) and the method is used for each cylinder of the internal combustion engine.

The invention also relates to an internal combustion engine or a commercial vehicle (eg bus or lorry) with an internal combustion engine, which is designed to carry out a method as herein.

It is also possible to use the method as disclosed herein for automobiles, large engines, off-road vehicles, stationary engines, marine engines, etc.

The preferred embodiments and features of the invention described above can be combined with one another as desired. Further details and advantages of the invention are described below with reference to the accompanying drawings. Show it:

FIG. 1 shows a schematic internal combustion engine that is suitable for carrying out a method according to the present disclosure;

Figure 2 is a diagram showing various pressure values over a crankshaft angle

Shows internal combustion engine;

Figure 3 is a diagram showing various pressure values and valve control curves over a

Shows crankshaft angle of an internal combustion engine according to the present disclosure; and

Figure 4 is a schematic flow diagram for an exemplary method according to the present disclosure.

The embodiments shown in the figures are at least partially identical, so that similar or identical parts are provided with the same reference numerals the explanation of which is also referred to the description of the other embodiments or figures in order to avoid repetitions.

FIG. 1 shows an internal combustion engine 10. The internal combustion engine 10 is designed as a multi-cylinder internal combustion engine, preferably as a six-cylinder in-line engine. However, the internal combustion engine can also have more or fewer cylinders and / or another arrangement of cylinders. The internal combustion engine 10 is preferably designed as a four-stroke internal combustion engine. The internal combustion engine 10 can preferably be designed as a diesel internal combustion engine. The internal combustion engine 10 can expediently be comprised in a motor vehicle, preferably a commercial vehicle (for example a truck or bus).

The exemplary internal combustion engine 10 has a first to sixth cylinder 12. The cylinders 12 are operated out of phase with one another by 120 ° crankshaft angle (KW). For example, the fifth cylinder of the plurality of cylinders 12 may be out of phase with the first cylinder of the plurality of cylinders 12 by -120 ° KW, etc. While, for example, the exhaust stroke begins in the fifth cylinder 12, the first cylinder of the plurality of cylinders is located 12 already in the middle of the exhaust stroke. If the internal combustion engine 10 has a different number of cylinders, the cylinders are accordingly differently offset from one another in phases, for example -720 ° KW / number of cylinders.

The cylinders 12 each have at least one inlet duct 14, a combustion chamber 16 and at least one outlet duct 18. The inlet channels 14 and the outlet channels 16 can be arranged, for example, in a cylinder head of the internal combustion engine 10. About the inlet channels 16 z. B. charge air to the combustion chambers 16 are supplied. Exhaust gas can be discharged from the combustion chambers 16 via the outlet channels 18.

The cylinders 12 also each have at least one intake valve 20 and at least one exhaust valve 22, preferably two intake valves 20 and two exhaust valves 22 per cylinder 12. The intake valves 20 can be used to establish a fluid connection between the intake channels 14 and the respective combustion chamber 16 of the cylinders 12 are manufactured. Using the exhaust valves 22, a fluid connection can be established between the combustion chambers 16 and the respective exhaust channels. The intake valves 20 and exhaust Valves 22 can be arranged in a cylinder head of internal combustion engine 10. For example, the inlet valves 20 and the outlet valves 22 can be designed as poppet valves.

The internal combustion engine 10 has an exhaust line 24. The exhaust line 24 is configured, for example, as a double flow, as shown, with a first exhaust manifold 26 and a second exhaust manifold 28. The first exhaust manifold 26 connects the exhaust ports 18 of the first three cylinders of the plurality of cylinders 12 to an exhaust gas turbine 30 of an exhaust gas turbocharger. The first exhaust manifold 26 supplies exhaust gas from the first three cylinders of the plurality of cylinders 12 to the exhaust gas turbine 30. The second exhaust manifold 28 connects the other three cylinders of the plurality of cylinders 12 to the exhaust turbine 30 to supply exhaust gas to the exhaust turbine 30. The exhaust line 24 can also have more or less exhaust gas flows or exhaust manifolds.

Those cylinders of the plurality of cylinders 12, the outlet channels 18 of which are connected directly to a common exhaust gas manifold 26 or 28, can in particular be operated out of phase by 240 ° KW.

An exhaust gas aftertreatment device 32 can be arranged downstream of the exhaust gas turbine 30. The exhaust gas aftertreatment device 32 can in particular have a device for the selective catalytic reduction of nitrogen oxides in the exhaust gas or an SCR catalytic converter device (SCR = selective catalytic reduction) 34. A nitrogen oxide conversion rate of the SCR catalyst device 34 can be temperature-dependent. Especially at low exhaust gas temperatures, e.g. For example, when starting the engine or during low-load operation of the internal combustion engine 10, an exhaust gas temperature may be too low for a desired nitrogen oxide conversion rate.

The method disclosed herein and an internal combustion engine that executes the method disclosed herein are able to raise an exhaust gas temperature during low-load operation using a pressure pulse in the exhaust system and by means of a double intake valve lift.

FIG. 2 shows different pressure profiles during an operating cycle of the internal combustion engine 10 in relation to one of the several cylinders 12 (hereinafter the “cylinder 12 in question”) for a low-load operating point. The dash-dotted curve A corresponds to an exemplary pressure curve in the inlet channel 14 of the cylinder 12 in question. The dotted curve B corresponds to an exemplary pressure curve in the respective outlet channel 18 of the cylinder 12 in question. The solid curve C corresponds to an exemplary pressure curve of a cylinder pressure in the ver combustion chamber 16 of the cylinder 12 in question.

Curve A shows that the pressure in the inlet duct 14 of the cylinder 12 under consideration is essentially constant. The pressure drops slightly when the intake valve 20 of the cylinder 12 under consideration is open in the intake stroke. In the intake stroke, charge air flows into the combustion chamber 16 of the cylinder 12 under consideration. During the other strokes, the pressure in the intake port 14 is essentially constant, with slight fluctuations, which are caused, for example, by opening and closing other intake valves 20 of other cylinders 12. For example, the pressure in the inlet duct 14 can be between 1.3 bar and 1.4 bar when the internal combustion engine 10 is operated under low load, as is shown by way of example.

Curve B shows that a pressure in the outlet channel 18 of the cylinder 12 under consideration fluctuates comparatively strongly during a cycle. When the outlet valve 22 of the cylinder 12 under consideration opens at the end of the expansion stroke, the pressure rises sharply and is gradually reduced, corresponding to a cylinder pressure curve C in this area. In addition, there are further pressure pulsations in the outlet channel 18 of the cylinder 12 under consideration, namely every 120 ° KW. The pressure positions are caused by the opening of the exhaust valves 22 of the other cylinders 12. In the example shown, the high pressure pulses during the compression stroke and the intake stroke are caused by those cylinders 12 which are connected to the same exhaust manifold 26 or 28 as the one under consideration Cylinder 12. The lower pressure pulses during the expansion stroke, the push-out stroke and at the end of the intake stroke into the compression stroke are brought about by those cylinders 12 which are connected to the other exhaust manifold 26 or 28 than the cylinder 12 under consideration Lower pressure pulses take place via a connection of the exhaust gas manifolds 26 and 28 through the exhaust gas turbine 30. This connection is indicated purely schematically by a dotted line in FIG. 1 and provided with the reference number 36.

Curve C shows that a cylinder pressure is greatly increased during the expansion stroke. In addition, it is shown in a region D that the cylinder pressure increases again in the second half of the push-out cycle (exhaust cycle). The reason for the increase is in the effect of the pressure pulse in the exhaust port 18 of the cylinder 12 under consideration (see curve B). This pressure pulse is brought about by the opening of the outlet valve 22 of a cylinder of the several cylinders 12 which is operated in a phase-shifted manner by -120 ° KW. This cylinder, which is operated with a phase shift of -120 ° KW, begins its exhaust stroke in this period at the beginning of the period in which exhaust gas is pushed out through the opened exhaust valve 22.

It was recognized that the increase in cylinder pressure caused by the pressure pulse in the exhaust line 24 in the cylinder 12 under consideration can have an effect such that the cylinder pressure (curve C) rises higher than the charge air pressure (curve A) due to the pressure pulse (curve B). In the exemplary embodiment with the six-cylinder internal combustion engine, the cylinder pressure of the cylinder 12 under consideration is higher than the boost pressure in a range of approximately 280 ° KW and 330 ° KW during the push-out cycle.

This knowledge can be used to convey residual gas, caused by the pressure pulse, from the combustion chamber 16 of the cylinder 12 in question into the inlet channel 14 of the cylinder 12 in question. It is proposed to open the intake valve 20 of the cylinder 12 under consideration during this phase in the exhaust stroke, in addition to the standard intake stroke during the intake stroke, as supplemented in FIG. 3.

In addition to the curves in FIG. 2, FIG. 3 also shows a valve control curve of the exhaust valve 22 of the cylinder 12 in question as a dotted curve E and a valve control curve of the inlet valve 20 of the cylinder 12 in question as a dash-dotted curve F.

Curve E shows that the exhaust valve 22 of the cylinder 12 under consideration is open during the exhaust stroke.

Curve 11 shows that the intake valve 20 of the cylinder 12 under consideration performs a double stroke. The intake valve 20 opens for the first time in the exhaust cycle, specifically while the pressure pulse increases the cylinder pressure in the combustion chamber 16 of the cylinder 12 under consideration via the boost pressure in the intake duct 14. Residual gas then flows through the opened inlet valve 20 into the inlet channel 14 of the cylinder 12 in question. The inlet valve 20 of the cylinder 12 in question then closes before the cylinder pressure in the combustion chamber 16 of the cylinder in question falls below the boost pressure again. The inlet valve 20 of the cylinder 12 under consideration then opens again normally in the intake stroke. Residual gas is flushed back from the inlet duct 14 into the combustion chamber 16 of the cylinder 21 under consideration in the intake stroke. At the same time, the fresh air mass in the combustion chamber 16 of the is reduced io

considered cylinder 12 around the mass of the residual gas. Due to the reduced air and therefore exhaust gas mass flow, the exhaust gas temperature rises with the engine torque remaining the same, without negatively influencing the engine's gas exchange work. The residual gas purge can be used to bring about an increase in the exhaust gas temperature in the exhaust line 24 under low load of the internal combustion engine 10 in order to increase a nitrogen oxide conversion rate of the SCR catalytic converter device 34.

The amount of residual gas in the low-load range can be preset via the stroke length and stroke height of the inlet valve 20 during the exhaust stroke. It is possible that the additional stroke of the inlet valve 20 has an effect on the maximum possible nominal power of the internal combustion engine. Series engines generally have a clearly negative purge gradient in nominal power, i.e. that is, the exhaust gas back pressure is significantly higher than the boost pressure. This also leads to increased residual gas rates in the nominal output. Therefore, the stroke size and stroke length of the additional stroke of the intake valve 20 must be designed correctly in order not to reduce the nominal output.

With regard to the stroke length, it is proposed for the exemplary six-cylinder internal combustion engine 10 that the inlet valve 20 of the cylinder 12 under consideration in a range between 100 ° KW after UT in the exhaust stroke of the cylinder 12 under consideration and 150 ° KW after UT in the exhaust stroke of the considered Cylinder 12 is open.

With regard to a maximum stroke of the inlet valve 20 of the cylinder 12 in question, it is proposed that this be less than 1/3 or less than 1/4 of a maximum stroke of the inlet valve 20 of the cylinder 12 in question during the intake stroke of the cylinder 12 in question during an intake stroke of the cylinder in question 12, e.g. B. around 1 mm to 2 mm, as shown.

In this way, the position, length and height of the additional stroke were arranged in such a way that as much residual gas as possible is flushed into the intake duct 14 in the visual load range and only a slight change occurs at “normal” control times in the case of higher engine loads in the main driving range.

The advantageous design of the additional stroke of the inlet valve 20 in the exhaust stroke means that the additional stroke can be carried out both under partial load and under full load without having a significantly negative effect under full load. This means that there is no need to provide a switchable system for selectively connecting the additional stroke of the inlet valve 20. Instead, it is sufficient if the inlet valve 20 is actuated by a robust, rigid, non-switchable cam of a camshaft, or generally driven by a rigid, non-switchable valve, which effects the same valve control curve for all load ranges. Thus, the valve control curve of the intake valve 20 under the light load of the internal combustion engine 10 is identical to that under the medium load and under the full load of the internal combustion engine 10.

From the above principle of utilizing the pressure pulsations in the exhaust line 24 of the internal combustion engine 10, a method for operating an internal combustion engine for increasing an exhaust gas temperature was derived, which is described in a highly simplified manner below with reference to FIG. 4 in connection with FIGS. 1 to 3.

In a method step S10, a pressure pulse is generated in the exhaust line 24 of the internal combustion engine 10. For example, the pressure pulse in the exhaust line 24 can be brought about by opening the exhaust valve 22 of one of the plurality of cylinders 12 during an exhaust stroke of this cylinder, as described with reference to FIGS. 2 and 3. However, within the scope of the teaching of the present disclosure, it is possible to use any other pressure pulse in the exhaust line 24 and / or to generate a pressure pulse in another way.

In a method step S12, the pressure pulse spreads in the exhaust line 24. The pressure pulse penetrates one of the several cylinders 12 into its combustion chamber 16 through an exhaust valve 22 which is already open in the exhaust stroke and increases the cylinder pressure there. The cylinder pressure is increased via the boost pressure in the inlet duct 14 of the same cylinder 12 (see area D in FIGS. 2 and 3).

In a method step S14, exhaust gas or residual gas is fed from the combustion chamber 16 into the inlet duct 14. The supply is made possible by the additional stroke of the intake valve 20 of the cylinder during the exhaust stroke (see FIG. 3). The inlet valve 20 is only opened after the cylinder pressure has been increased above the boost pressure. The intake valve 20 is closed before the cylinder pressure falls below the boost pressure.

In a method step S16, the exhaust gas is flushed back from the intake duct 14 into the combustion chamber of the cylinder 12 during the intake stroke. As previously explained, this may increase an exhaust gas temperature in the low load to increase a nitrogen oxide conversion rate of the SCR catalyst device. Even if the method is only described for one of the cylinders 12, it can in principle be used for each of the plurality of cylinders 12. Then, for example, a different cylinder operated out of phase causes the pressure pulse in the exhaust line 24.

The invention is not restricted to the preferred exemplary embodiments described above. Rather, a large number of variants and modifications are possible which also make use of the inventive idea and therefore fall within the scope of protection. In particular, the invention also claims protection for the subject and the features of the subclaims independently of the claims referred to. In particular, the features of independent claim 1 are disclosed independently of one another. In addition, the features of the subclaims are also disclosed independently of all the features of independent claim 1. All of the range indications herein are to be understood as meaning that, as it were, all values falling within the respective range are disclosed individually, e.g. B. also as the respective preferred external borders of the respective area.

Reference list

10 internal combustion engine

12 cylinders

14 inlet channels

16 combustion chambers

18 outlet channels

20 intake valves

22 exhaust valves

24 exhaust system

26 First exhaust manifold 28 Second exhaust manifold 30 Exhaust turbine

32 exhaust gas aftertreatment device 34 SCR catalytic device 36 connection

A-C pressure curves

D pressure pulse

E-F valve timing curves

Claims

1. A method for operating an internal combustion engine (10), comprising:

Generating a pressure pulse in an exhaust line (24) of the internal combustion engine

(10);

Feeding exhaust gas from a combustion chamber (16) of a cylinder (12) during an exhaust stroke of the cylinder (12) into an inlet channel (14) of the cylinder (12) by spreading the pressure pulse from the exhaust gas line (24) into the combustion chamber ( 16) of the cylinder (12); and

Feeding the exhaust gas from the inlet channel (14) of the cylinder (12) into the combustion chamber (16) of the cylinder (12) during an intake stroke of the cylinder (12).

2. The method of claim 1, wherein:

the pressure pulse in the exhaust line (24) is generated by opening an exhaust valve (22) of a further cylinder (12) of the internal combustion engine (10) during an exhaust stroke of the further cylinder (12).

3. The method of claim 2, wherein:

the further cylinder (12) is operated out of phase with the cylinder (12), preferably out of phase by approximately -120 ° KW and / or by -720 ° KW / number of cylinders of the internal combustion engine (10).

4. The method according to any one of the preceding claims, wherein:

the supply of exhaust gas from the combustion chamber (16) of the cylinder (12) is brought about only by an increase in a cylinder pressure in the combustion chamber (16) of the cylinder (12) by the pressure pulse, preferably by an increase in the boost pressure in the inlet duct (14) of the cylinder (12) and / or the internal combustion engine (10).

5. The method according to any one of the preceding claims, wherein:

the pressure pulse propagates through an open exhaust valve (22) of the cylinder (12), preferably during an exhaust stroke of the cylinder (12), from the exhaust line (24) into the combustion chamber (16) of the cylinder (12).

6. The method according to any one of the preceding claims, wherein:

the supply of exhaust gas from the combustion chamber (16) of the cylinder (12) into the inlet channel (14) of the cylinder (12) by the pressure pulse by opening an inlet valve (20) of the cylinder (12), preferably during an exhaust stroke of the cylinder - The (12) and / or during the pressure pulse takes place; and or

the exhaust gas is fed from the inlet channel (14) of the cylinder (12) into the combustion chamber (16) of the cylinder (12) during an intake stroke of the cylinder (12) by opening an inlet valve (20) of the cylinder (12).

7. The method of claim 6, wherein:

the inlet valve (20) of the cylinder (12) only opens when the pressure pulse propagates into the combustion chamber (16) of the cylinder (12); and or

the inlet valve (20) of the cylinder (12) only opens when the cylinder pressure in the combustion chamber (16) of the cylinder (12) is triggered by the pressure pulse via a boost pressure in the inlet channel (14) of the cylinder (12) and / or the internal combustion engine (10 ) is increased; and or

the inlet valve (20) of the cylinder (12) closes if or before the cylinder pressure in the combustion chamber (16) of the cylinder (12) again falls below a boost pressure in the inlet channel (14) of the cylinder (12) and / or the internal combustion engine ( 10) drops.

8. The method of claim 6 or claim 7, wherein:

the inlet valve (20) of the cylinder (12) opens at the beginning of the exhaust stroke of the further cylinder (12); and or

the inlet valve (20) of the cylinder (12) opens when the outlet valve (22) of the further cylinder (12) opens; and or

the inlet valve (20) of the cylinder (12) opens in the exhaust stroke of the cylinder (12) and closes before the end of the exhaust stroke of the cylinder (12).

9. The method according to any one of claims 6 to 8, wherein:

the inlet valve (20) of the cylinder (12) is open in a range between 100 ° KW after UT in the working cycle of the cylinder (12) and 150 ° KW after UT in the exhaust stroke of the cylinder (12); and or

the inlet valve (20) of the cylinder (12) opens at approximately or after 100 ° CA after UT in the exhaust stroke of the cylinder (12); and or

the inlet valve (20) of the cylinder (12) closes at approximately or before 150 ° CA after UT in the exhaust stroke of the cylinder (12); and or the inlet valve (20) of the cylinder (12) in the exhaust stroke of the cylinder (12) is open for approximately or less than 50 ° KW.

10. The method according to any one of claims 6 to 9, wherein:

a maximum stroke of the intake valve (20) of the cylinder (12) during the exhaust stroke of the cylinder (12) is less than a maximum stroke of the intake valve (20) of the cylinder (12) during an intake stroke of the cylinder (12); and or

a maximum stroke of the inlet valve (20) of the cylinder (12) during the exhaust stroke of the cylinder (12) is less than 1/3 or less than 1/4 of a maximum stroke of the inlet valve (20) of the cylinder (12) during an intake stroke of the cylinder (12); and / or a maximum stroke of the inlet valve (20) of the cylinder (12) during the exhaust stroke of the cylinder (12) is less than 3 mm, preferably between 1 mm and 2 mm.

1 1. The method according to any one of claims 6 to 10, wherein:

a valve timing curve of the intake valve (20) of the cylinder (12) is invariable; and or

a valve control curve of the inlet valve (20) of the cylinder (12) is effected by a non-switchable and / or rigid cam of a camshaft of the internal combustion engine (10), and / or

an actuating device, preferably a valve train, for actuating the inlet valve (20) of the cylinder (12) is rigid and / or non-switchable; and or

is a valve control curve of the inlet valve (20) of the cylinder (12) under low load of the internal combustion engine (10) as under medium load and / or under full load of the internal combustion engine (10).

12. The method according to any one of the preceding claims, further comprising:

Operating the internal combustion engine (10) under low load during the generation of the pressure pulse, the supply of exhaust gas from the combustion chamber (16) and the supply of the exhaust gas from the inlet duct (14); and or

Operating the internal combustion engine (10) in a range up to 30%, up to 35% and / or up to 40% load and / or in a low speed range, preferably between 800 rpm and 1400 rpm, during the generation of the pressure pulse, supplying exhaust gas from the combustion chamber (16) and supplying the exhaust gas from the inlet duct (14).

13. The method according to any one of the preceding claims, wherein: the method for increasing an exhaust gas temperature in the exhaust line (24) is carried out, preferably under low load of the internal combustion engine (10), preferably for increasing a conversion rate of an SCR catalyst device (34) in the exhaust line (24).

14. The method according to any one of the preceding claims, wherein:

the internal combustion engine (10) has a plurality of cylinders (12) and the method is used for each cylinder (12) of the internal combustion engine (10).

15. Internal combustion engine (10) or commercial vehicle with an internal combustion engine (10) which is designed to carry out a method according to one of the preceding claims.