DE102006016432A1 - Method for controlling EGR in turbocharged IC engine has a connecting port between parallel exhaust ducts close to turbo unit - Google Patents

Abstract

A method for controlling the EGR for a turbocharged IC engine has the exhaust duct (3) in two parts separated by a wall (5) and with controlled exhaust flow from one exhaust duct. A port in the separating wall close to the turbo unit enables pressure pulses from both ducts to be passed to the EGR duct (10, 11) in one side of the exhaust system. The connecting port can have a variable shutter which can be operated in relation to the engine performance.

Description

The The invention relates to an internal combustion engine with a crankcase and a plurality of cylinders forming a combustion chamber of cylinder heads are covered, wherein in the cylinder heads inlet channels and outlet channels embedded are, with the outlet channels with a two-flowed and at least partially separated strands split exhaust manifold are connected in the turbine housing of a Exhaust gas turbocharger opens and a method of operating such an internal combustion engine.

Such an internal combustion engine is from the DE 39 36 171 A1 known. This internal combustion engine is designed as a six-cylinder series internal combustion engine and has a two-flow and at least partially divided into separate strands exhaust manifold, wherein in each strand three recessed into the cylinder head of the internal combustion engine discharge channels open. The two strands meet in the middle of the row of cylinders and are deflected there and connected in parallel with the turbine housing of an exhaust gas turbocharger. In this case, the parallel arranged region of the two strands is separated by a separating web. In the divider, a cold room is embedded, from which this thermally highly stressed area can be cooled. If necessary, the separating web continues with the cooling space into the turbine housing of the exhaust gas turbocharger.

Of the Invention is based on the object, an internal combustion engine and to provide a method for operating an internal combustion engine, at the recirculated exhaust gas amount can be influenced with simple means.

These Task is in accordance with the method claim solved by that by a transfer or an opening in a divisional dividing web of the exhaust manifold In the area immediately in front of the turbine housing exhaust gas from the first strand the exhaust manifold is überverschbar in the second strand and that the pushed over Exhaust gas in a connected to the second strand single-flow Exhaust gas recirculation line the pressure conditions affected. The device is characterized in that a the double - flow forming divider of the exhaust manifold in Region immediately before the turbine housing has an opening and that of the second strand of the exhaust manifold a single-flow exhaust gas recirculation line branches. While one at conventional Exhaust systems the separation of the two strands of a particular six-cylinder Exhaust system into the area of the turbine housing of the exhaust gas turbocharger up to has led just before the blades of the turbine wheel, about every pressure pulse of the flowing Exploiting exhaust gas to drive the turbine wheel dissolves the invention of this teaching. Through the opening in the divider becomes Exhaust gas from a cylinder located in the expansion stroke of the Cylinder row has been ejected in a strand of the exhaust manifold is pushed into the second strand and causes a pressure increase there, which is in an exhaust gas recirculation line connected to this line continues. This formed as a single-flow system exhaust gas recirculation line is possibly over a Check valve, an exhaust gas cooler and a control valve with the fresh gas line on the pressure side the compressor of the exhaust gas turbocharger preferably connected behind a charge air cooler. The connection point of the exhaust gas recirculation line to the second branch of the exhaust manifold is preferably selected so that a pressure maximum setting in the strand caused by the clashing ones Waste gas streams, is exploited.

In Development of the invention, the amount of pushed-over exhaust gas is adjustable, wherein in a further embodiment, the setting in dependence of operating parameters of the internal combustion engine takes place. In the basic version becomes the opening by a shortening formed of the divider, wherein for the controlled shutter may be provided a flap, for example can be adjusted by an electric drive. Through these measures can be customized to requirements, such as maximum exhaust gas recirculation or maximum pressurization of the exhaust gas turbocharger are received.

Further advantageous embodiments of the invention are the drawing description can be seen in the illustrated in the figure embodiment closer to the invention is described.

The single figure shows a schematic representation of the exhaust system of a six-cylinder auto-ignition internal combustion engine, which is preferably equipped with a common rail injection system. This internal combustion engine has six arranged in a row cylinder, each of a cylinder head 1 are covered under formation of a combustion chamber. For the present invention, it is basically irrelevant whether the cylinder heads 1 are designed as single heads or as a block cylinder head for all six cylinders. In every cylinder head 1 at least one outlet channel is inserted, which opens on a cylinder head side wall. With these exhaust ports is an exhaust manifold 2 screwed, which is formed zweiplutig and accordingly two strands 3a . 3b having. The two strands 3a . 3b Run along the row of cylinders toward each other and meet in the area between the third and fourth cylinder and each other are deflected there and are parallel to each other with the turbine housing 4 connected to an exhaust gas turbocharger. In the parallel section of the two strands 3a . 3b These are through a divider 5 separated. This divider 5 extends to just before the entrance of the exhaust manifold 2 in the turbine housing 4 and thus points in front of the turbine housing 4 a crossing or an opening 12 on. This opening 12 is optionally closed by a flap closed.

The exhaust gas of the internal combustion engine then flows through the turbine housing during operation of the internal combustion engine 4 the exhaust gas turbocharger and drives its turbine 6 at. This is about a shaft with the compressor 7 connected, compressed from the environment sucked combustion air and after cooling in a charge air cooler 8th in a fresh gas line 9 forwards. This fresh gas line 9 is with the intake ports in the individual cylinder heads 1 connected.

From the strand 3b branches an exhaust gas recirculation line 10 starting with the involvement of an exhaust gas recirculation flap 11 , and optionally a check valve and a heat exchanger with the fresh gas line 10 connected is.

Through the through the shortened jetty 5 formed opening immediately in front of the turbine housing 4 For example, occurs when one of the cylinders of the strand 3a in the expansion stroke, exhaust gas in the strand 3b and leads there to a brief increase in pressure. This pressure increase is for an increase in the exhaust gas recirculation line 10 used recirculated exhaust gas.

1

cylinder head

2

Exhaust manifold

3a, 3b

strand

4

turbine housing

5

divider

6

turbine

7

compressor

8th

Intercooler

9

Fresh gas line

10

Exhaust gas recirculation line

11

Exhaust gas recirculation valve

12

opening

Claims (6)

Internal combustion engine with a crankcase and a plurality of cylinders, which are covered to form a combustion chamber of cylinder heads, wherein in the cylinder heads inlet channels and outlet channels are recessed, wherein the outlet channels with a double-flow and at least partially separated into separate strands exhaust manifold are connected, which in the turbine housing of a Exhaust gas turbocharger opens, characterized in that a double-flight forming separating web ( 5 ) of the exhaust manifold ( 2 ) in the area immediately in front of the turbine housing ( 4 ) a passage or an opening ( 12 ) and that from a second strand ( 3b ) an exhaust gas recirculation line ( 10 ) branches off. Internal combustion engine according to claim 1, characterized in that the opening ( 12 ) by a shortening of the separating web ( 5 ) is formed. Internal combustion engine according to claim 1 or 2, characterized in that the opening ( 12 ) is controllably lockable. A method of operating an internal combustion engine having a crankcase and a plurality of cylinders, which are covered to form a combustion chamber of cylinder heads, wherein in the cylinder heads inlet channels and outlet channels are recessed, wherein the outlet channels with a double-flow and at least partially separated strands exhaust manifold are interconnected, the the turbine housing of an exhaust gas turbocharger opens, characterized in that by a passage or an opening ( 12 ) into a dividing web forming the double-flow ( 5 ) of the exhaust manifold ( 2 ) in the area immediately in front of the turbine housing ( 4 ) Exhaust gas from the first strand ( 3a ) of the exhaust manifold ( 2 ) in the second strand ( 3b ) and that the pushed-over exhaust gas in one at the second strand ( 3b ) connected exhaust gas recirculation line ( 10 ) influences the pressure conditions. Method according to claim 4, characterized in that that the amount of pushed over Exhaust gas is adjustable. Method according to claim 4 or 5, characterized in that the opening ( 12 ) is adjustable in dependence on operating parameters of the internal combustion engine.