DE102014216461A1 - Internal combustion engine - Google Patents

Abstract

Internal combustion engine with a cylinder head for four cylinders in series and with an intake side and an exhaust side gas exchange valve train, wherein inside the cylinder head, a first exhaust passage of the first cylinder in a second exhaust passage of the second cylinder and a fourth exhaust passage of the fourth cylinder in a third exhaust passage of the third Cylinder opens, wherein a control time of the outlet side gas exchange valve train can be shortened. The inventive design of the internal combustion engine achieves improvements in terms of fuel consumption and response.

Description

The invention relates to an internal combustion engine having the features of the preamble of patent claim 1.

The technical environment, for example, the German patent application DE 10 2011 109 762 A1 pointed. From this, an internal combustion engine for a motor vehicle is known, with a first cylinder bank and a second cylinder bank. Furthermore, this internal combustion engine has an exhaust tract with a first exhaust manifold and a second exhaust manifold, wherein the first cylinder bank, the first exhaust manifold with a first exhaust gas flow and the second cylinder bank, the second exhaust manifold is associated with a second exhaust gas flow. Furthermore, the internal combustion engine has a first exhaust gas turbocharger and a second exhaust gas turbocharger, wherein the first exhaust gas turbocharger comprises a first turbine arranged in the exhaust gas tract and the second exhaust gas turbocharger comprises a second turbine arranged in the exhaust gas tract. The first turbine and the second turbine can be driven alternately by at least a part of the exhaust gas from the first cylinder bank and the second cylinder bank with the aid of a switchable between at least three positions and arranged upstream of the first turbine and the second turbine valve means. In this case, the first turbine has a flood in the first position of the valve device of exhaust gas from the first exhaust gas flow of the first cylinder bank and a second, in the first position of the valve device of exhaust gas from the second exhaust gas flow of the second exhaust gas flow through the flood.

A disadvantage of this known embodiment of the internal combustion engine, the summary of the exhaust gas flows, as occurs by close Zündabstände crosstalk of exhaust gas, which has a negative effect on the power output of the internal combustion engine.

Next is from the European patent application EP 2 503 125 A1 , from which the present invention proceeds, a supercharged internal combustion engine with two exhaust gas turbochargers and a cylinder head with four along the longitudinal axis of the cylinder head arranged in series cylinders known. Each of the cylinders has two discharge ports for discharging the exhaust gases, followed by an exhaust pipe, in which the exhaust pipes of two cylinders within the cylinder head form two exhaust manifolds integrated in the cylinder head and merge into two total exhaust pipes. In this case, the inlet region of the turbine of the first exhaust-gas turbocharger with the first overall exhaust-gas line and the inlet region of the turbine of the second exhaust-gas turbocharger are connected to the second overall exhaust gas line. Further, between the two turbines and the two exhaust pipes, the cylinder head has a projection having an opening connected to the exit region of each turbine. In this projection, the subsequent channels are brought together to form a common exhaust pipe, which emerges from the projection.

Also in this known embodiment, the close ignition distance in the adjacent cylinder grouping leads to power losses due to crosstalk of exhaust gas.

The object of the present invention is to show a measure in order to avoid the above-mentioned disadvantageous power losses.

This object is achieved by the feature in the characterizing part of patent claim 1.

It is thus proposed an integrated in the cylinder head of an internal combustion engine exhaust manifold with merging the exhaust gas flows (exhaust channels) first and second cylinders and third and fourth cylinder. By minimizing the volume of exhaust gas in the exhaust optimal dynamic response (improved response of the engine) is achieved. Due to the reduced outlet control times according to the invention, the harmful effects of the residual gas purging in the time-adjacent cylinders due to the short firing interval, can be avoided. The cooling surfaces of the exhaust ducts are reduced, so the cylinder head integrated exhaust manifold is also applicable to vehicles with limited cooling options. This brings advantages in terms of fuel consumption and engine response.

According to claim 2, the exhaust dynamic disadvantages of the smallest firing interval of only 180 ° crank angle in each of the two floods are reduced by reducing the exhaust-side control time to below about 180 ° to 200 ° crankshaft. This can be limited by the use of a time-variable exhaust-side gas exchange valve train and / or the reduction of the valve with a variable displacement exhaust-side gas exchange valve train, for example, 7 mm only in this sensitive area low engine speeds.

With the embodiment according to claim 3, when using two exhaust gas turbochargers or an exhaust gas turbocharger in Twinscroll design, the shorter exhaust gas flow act directly on the turbine (s) of the exhaust gas turbocharger, whereby a very fast response is achieved.

The ignition sequences according to the claims 4 and 5 are two particularly preferred ignition sequences.

The embodiment according to claim 6 allows, in particular when operating with one or two exhaust gas turbochargers best possible temperature of the exhaust gas to avoid overheating of the turbine (s).

Advantageously, the internal combustion engine according to claim 7 and 8 have either four or even eight cylinders. As eight-cylinder engine in V-construction, this has a "plane" crankshaft.

In the following the invention with reference to an embodiment in a single figure is explained in more detail.

1 schematically shows a cylinder head for an internal combustion engine according to the invention.

1 shows very schematically a cylinder head 5 for an internal combustion engine according to the invention. In the internal combustion engine is a four-cylinder internal combustion engine, with the four cylinders 1 . 2 . 3 . 4 arranged in a row. The cylinders 1 . 2 . 3 . 4 are represented symbolically by circles. The cylinder head 5 has an inlet-side and a likewise not shown outlet-side gas exchange valve drive, not shown.

Starting from a control shaft 10 , which is provided for accommodating a drive for the intake side and the exhaust side valve train, starts the numbering of the cylinder 1 , Cylinder 2 , Cylinder 3 and cylinders 4 , Inside the cylinder head 5 are four exhaust outlet ducts 6 . 7 . 9 . 8th for the four cylinders 1 . 2 . 3 . 4 intended. A first outlet channel 6 is for the first cylinder 1 provided, a second outlet channel 7 is for the second cylinder 2 provided, a third outlet channel 9 is for the third cylinder 3 provided, a fourth outlet channel 8th is for the fourth cylinder 4 intended. In the schematic illustration, the outlet channels are sufficient 6 . 7 . 8th . 9 not quite up to the cylinder 1 . 2 . 3 . 4 ran, are in reality, however, exhaust gas leader connected via gas exchange valves with each other.

According to the invention, a control time of the outlet-side gas exchange valve drive is variable. Thus, a cylinder head integrated exhaust manifold with merger of the exhaust gas flows (exhaust passages) for cylinder 1 and 2 as well as cylinders 3 and 4 proposed. The exhaust-dynamic disadvantages of the smallest ignition interval of 180 ° crank angle in each of the two exhaust gas flows 6 and 7 such as 9 and 8th be corrected for example by reducing the exhaust-side control time to about 180 ° to 200 ° crank angle. This can be either permanently or preferably by the use of a variable-stroke and / or time-variable valve train and by the reduction of the outlet side Gaswechselventilhubes, z. B. to 7 mm, be limited only in this sensitive area low speeds of the engine. By minimizing the volume of exhaust gas in the exhaust optimal dynamic response (improved response of the engine) is achieved. Furthermore, by means of the short outlet control times, the harmful effects of the rinsing gas purging in the chronologically adjacent cylinders can be avoided. Since the cooling surface of the exhaust gas is reduced, the cylinder head integrated exhaust manifold is also applicable to vehicles with limited cooling options. The inventive design provides advantages in fuel consumption and the response of the internal combustion engine.

Like in the 1 Although shown schematically but still recognizable, the outlet channel lengths of the first and fourth outlet channels 6 . 8th in the cylinder head 5 longer than the outlet channel lengths of the second and third outlet channels 7 . 9 , This brings advantages in particular when using an exhaust gas turbocharger in twin-scroll design or when using two monoscroll turbochargers, since the exhaust gases of the second and third cylinders 2 . 3 be passed directly to the turbines of the turbocharger, whereby a very fast response is achieved.

• a) Zündfolge: Zylinder 1, 3, 4, 2
• b) Zündfolge: Zylinder 1, 2, 4, 3

With the embodiment according to the invention are two different Zündreihenfolgen for the four cylinders 1 . 2 . 3 . 4 displayed:

• a) firing order: cylinder 1 . 3 . 4 . 2
• b) firing order: cylinder 1 . 2 . 4 . 3

In a particularly preferred embodiment, the cylinder head 5 liquid cooled. Thus, the temperature of the hot exhaust gas in the cylinder head 5 take place, whereby the exhaust gas temperatures, especially in exhaust gas turbocharger operation can be lowered to harmless temperatures.

LIST OF REFERENCE NUMBERS

1

first cylinder

2

second cylinder

3

third cylinder

4

fourth cylinder

5

cylinder head

6

first outlet channel

7

second outlet channel

8th

fourth outlet channel

9

third outlet channel

10

control shaft

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102011109762 A1 [0002]
• EP 2503125 A1 [0004]

Claims (8)

Internal combustion engine with a cylinder head ( 5 ) for four cylinders ( 1 . 2 . 3 . 4 ) in series and with an intake side and an exhaust side gas exchange valve train, wherein within the cylinder head ( 5 ) a first outlet channel ( 6 ) of the first cylinder ( 1 ) in a second outlet channel ( 7 ) of the second cylinder ( 2 ) and a fourth outlet channel ( 8th ) of the fourth cylinder ( 4 ) in a third outlet channel ( 9 ) of the third cylinder ( 3 ), characterized in that a control time of the outlet side gas exchange valve train can be shortened. Internal combustion engine according to claim 1, characterized in that the control time via a lift and / or time-variable valve train is variable. Internal combustion engine according to claim 1 or 2, characterized in that an outlet channel length of the first and the second outlet channel ( 6 . 7 ) in the cylinder head ( 5 ) is longer than an outlet channel length of the second and the third outlet channel ( 7 . 9 ). Internal combustion engine according to one of claims 1 to 3, wherein the internal combustion engine has a firing order for the cylinders, characterized in that the firing order of the first cylinder ( 1 ), third cylinder ( 3 ), fourth cylinder ( 4 ), second cylinder ( 2 ). Internal combustion engine according to one of the claims 1 to 3, characterized in that the firing order of the first cylinder ( 1 ), second cylinder ( 2 ), fourth cylinder ( 4 ), third cylinder ( 3 ). Internal combustion engine according to one of the claims 1 to 5, characterized in that the cylinder head is liquid-cooled. Internal combustion engine according to one of the claims 1 to 6, characterized in that the internal combustion engine is a four-cylinder internal combustion engine. Internal combustion engine according to one of the claims 1 to 6, characterized in that the internal combustion engine is an eight-cylinder internal combustion engine.

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