DE102015107532B4 - internal combustion engine - Google Patents

Abstract

Internal combustion engine (1) with several cylinder groups (2, 3) each consisting of several cylinders and with several exhaust gas turbochargers (7, 7.1, 9, 9.1), a first cylinder group (2) having a first exhaust gas turbocharger (7) and a second exhaust gas turbocharger (9) assigned and wherein a first exhaust gas turbocharger (7.1) and a second exhaust gas turbocharger (9.1) are assigned to a second cylinder group (3), in such a way that the cylinder of the first cylinder group (2) from the first exhaust valves (4) and the cylinder from the first exhaust valves (4.1) Cylinders of the second cylinder group (3) via a respective first exhaust manifold (6, 6.1) of the respective cylinder group (2, 3) exhaust gas can be supplied to the respective first exhaust gas turbocharger (7, 7.1) of the respective cylinder group (2, 3) that from second exhaust valves (5) the cylinder of the first cylinder group (2) and from second exhaust valves (5.1) the cylinder of the second cylinder group (3) exhaust gas via a second exhaust manifold (8, 8.1) of the respective cylinder group (2, 3) Exhaust gas can be fed to the respective second exhaust gas turbocharger (9, 9.1) of the respective cylinder group (2, 3), the exhaust manifolds (6, 6.1, 8, 8.1) per cylinder group (2, 3) each having one exhaust gas turbocharger (7, 7.1, 9, 9.1) of the respective cylinder group (2, 3) can be connected, which can be acted upon in a controllable or regulatable manner by means of a respective overflow valve (12, 13) with the exhaust gas flow, characterized in that the respective overflow valve (12, 13) in the Exhaust manifolds (6, 6.1, 8, 8.1) of the respective cylinder group (2, 3) is arranged, with opening and closing of the overflow valves (12, 13) with opening and/or closing of control valves (10, 11) of the exhaust gas turbochargers ( 7, 7.1, 9, 9.1).

Description

The invention relates to an internal combustion engine with a plurality of cylinder groups according to the preamble of claim 1.

In the case of internal combustion engines for motor vehicles, it is considered a particularly effective measure for reducing fuel consumption and CO ₂ emissions to reduce displacement and try to achieve power by so-called supercharging of the internal combustion engine, generally referred to as "downsizing". In particular, if this measure is combined with direct injection of the fuel, a significant reduction in fuel consumption and a significant reduction in CO ₂ emissions can be achieved. A large number of possible solutions are known from the prior art, some of which also deal with the special features of the operation of the charger required for charging, in particular the exhaust gas turbocharger.

In the DE 10 2004 035 324 A1 shows and describes sequential supercharging for an internal combustion engine in which, when two exhaust gas turbochargers are arranged in the exhaust pipe, a shut-off device is provided, via which only one of the two exhaust gas turbochargers is charged with exhaust gas in the lower and middle partial load range for optimal operation of the charger.

From the DE 10 2005 039 013 A1 an internal combustion engine with two exhaust gas turbochargers is shown and described in which a connecting line is provided between the two exhaust gas lines leading to the chargers, in which the exhaust gas from the combustion chambers can only be fed to one of the two turbochargers via the exhaust gas from the combustion chambers, for example at low engine speeds or low exhaust gas mass flows.

In the DE 10 2006 061 345 A1 Another register supercharging is disclosed, in which two exhaust gas turbochargers connected in parallel should be controllable via a valve device in such a way that they can always be operated in an optimal operating state.

In the DE 10 2007 046 655 A1 a method for operating an internal combustion engine and a corresponding internal combustion engine is shown and described. Depending on the respective operating state of the internal combustion engine, exhaust gas is to be routed either past one of the turbochargers or exclusively to one of the two turbochargers via an exhaust gas bypass.

In the EP 2 333 274 A1 register charging is shown and described in which control is to be carried out during operation as a function of the pressure in the exhaust system.

More individual solutions for the operation of supercharged internal combustion engines are in the EP 1 645 735 A1 , in the WO 91/07577 A1 and in the JP 2009-174364 A shown.

the DE 10 2010 060 107 A1 shows and describes a supercharged internal combustion engine with two separate cylinder groups, each of which is assigned an exhaust gas turbocharger. The exhaust gas is routed separately from each cylinder group to the exhaust gas turbocharger assigned to each cylinder group.

DE 10 2010 060 106 A1 discloses a supercharged internal combustion engine according to the preamble of claim 1.

Proceeding from this state of the art, the invention is based on the object of achieving exhaust gas supercharging that is further improved in its operating behavior over all operating states while at the same time reducing fuel consumption and lowering CO ₂ emissions.

The invention solves this problem with an internal combustion engine according to claim 1.

The overflow valves are located in the exhaust manifolds. The control or regulation of the overflow valves in the exhaust gas flow leading to the exhaust gas turbochargers takes place in cooperation with a corresponding valve control of the exhaust gas turbocharger or turbochargers.

In such a solution, depending on the operating state of the internal combustion engine, the exhaust gas can only be fed to one or both exhaust gas turbochargers in the exhaust lines per cylinder group by means of the overflow valves.

The control valves of the exhaust gas turbocharger(s) are opened or closed in connection with the open and/or closed position of the overflow valves. A particularly rapid run-up of the exhaust gas turbocharger, which is initially not acted upon, is achieved in that the overflow valve is opened when the control valves for this exhaust gas turbocharger are closed.

A particularly preferred mode of operation can be seen in the fact that the overflow valves are used exclusively for pressurizing in part-load operation or in stationary operation or also in full-load operation of the internal combustion engine in a lower speed range gene of one of the exhaust gas turbochargers are completely closed.

When the internal combustion engine is operating under full load in a medium or upper speed range, the overflow valves can preferably be openable in order to apply pressure to both turbochargers.

When the overflow valve and control valves of one of the two turbochargers for one of the two cylinder groups are closed, e.g. in the starting phase of the internal combustion engine, only one of the turbochargers is acted upon.

When the internal combustion engine is operating under full load, the overflow valves are open; for the one or more controllable exhaust gas turbochargers, the exhaust gas flow bypass valves are closed and the valve in the outflow area of the exhaust gas turbocharger is opened. In this operating state, both exhaust gas turbochargers are acted upon by the respective full exhaust gas flow via the exhaust manifold assigned to them and are in full operating state.

With such a solution, each with two exhaust gas turbochargers and separate exhaust gas routing to the exhaust gas turbochargers per cylinder group, it is conceivable that only one of the two exhaust gas turbochargers can be controlled via valve controls, e.g. via a bypass valve to divert the exhaust gas flow around the exhaust gas turbocharger or a shut-off valve for Dissipation of the exhaust gas after its charging in the controllable exhaust gas turbocharger.

In the drawing, an embodiment of the subject invention is shown and described. Features, preferred developments and details of the subject matter of the invention are to be explained in more detail on the basis of this exemplary embodiment.

However, the invention is not limited to the embodiment shown and described, for example with six cylinders. Rather, the invention can also be implemented on an internal combustion engine with two separate cylinder groups if these include two, four or even more cylinders in a V, W or in-line or boxer arrangement, for example.

• 1 den Erfindungsgegenstand bei einer z.B. 6-zylindrigen Brennkraftmaschine.
• 2 einen ersten Betriebszustand im Abgasstrang einer Brennkraftmaschine nach der Erfindung;
• 3 einen zweiten Betriebszustand der Brennkraftmaschine nach 2;
• 4 einen dritten Betriebszustand einer Brennkraftmaschine nach der Erfindung entsprechend 2;
• 5 die Anordnung eines Überströmventils am Gegenstand nach der Erfindung in den Abgaskrümmern/Zuleitung zu den Abgasturboladern und
• 6 die Anordnung des Überströmventils zwischen den beiden Abgaskrümmern.

The drawing only shows a schematic representation of the subject of the invention, based on the course of the exhaust gas flows from the cylinder outlet to after charging by the exhaust gas turbocharger. It shows:

• 1 the subject of the invention in a 6-cylinder internal combustion engine, for example.
• 2 a first operating state in the exhaust system of an internal combustion engine according to the invention;
• 3 a second operating state of the internal combustion engine 2 ;
• 4 corresponding to a third operating condition of an internal combustion engine according to the invention 2 ;
• 5 the arrangement of an overflow valve on the object according to the invention in the exhaust manifolds / supply line to the exhaust gas turbochargers and
• 6 the arrangement of the overflow valve between the two exhaust manifolds.

An internal combustion engine 1 with two 3-cylinder cylinder groups 2 and 3 each has, in a manner known per se from the prior art, two inlet valves for each of the cylinders and also two outlet valves 4 and 5 for each of the cylinders. The exhaust valves 4 or 4.1 of all three cylinders are connected via a common exhaust manifold 6 or 6.1 with regard to the exhaust gas flow after the combustion process in the cylinder. Likewise, the exhaust valves 5 and 5.1 of all three cylinders are connected to one another in series via a common exhaust manifold 8 and 8.1.

The common exhaust manifold 6 of the exhaust valves 4 of the first cylinder group 2 is connected to a first exhaust gas turbocharger 7; the exhaust manifold 8 of the first cylinder group 2, into which the exhaust gases flowing out of the exhaust valves 5 after the combustion process flow, is connected to a second exhaust gas turbocharger 9.

In a corresponding manner, the exhaust valves 4.1 and 5.1 of the second cylinder group 3 are connected to common exhaust manifolds 6.1 and 8.1 and accordingly lead the exhaust gas to a first turbocharger 7.1 of the second cylinder group 3 and a second exhaust gas turbocharger 9.1 of the second cylinder group 3.

All - or just one - of the exhaust gas turbochargers 7, 7.1 or 9 and 9.1 can be valve-controlled in a manner known from the prior art, e.g. via a "bypass" valve and a check valve arranged in the outflow of the exhaust gas turbocharger.

The exhaust gas correspondingly charged in the exhaust gas turbochargers 7, 7.1, 9, 9.1 is—possibly after cooling—compressed again in a known manner to the fuel/air mixture fed to the combustion chambers via the inlet valves or via catalytic converters also arranged in a known manner gates Cat 1-3, Cat4-6 and via the exhaust system ESD 1-3, ESD 4-6.

The functioning of the subject of the invention is based on the 2-4 shown in three operating states.

In a first operating state (see 2 ) - eg in the starting phase or in stop-and-go operation - the outlet valve 4 can be opened via a corresponding valve control with full lift, while the outlet valve 5 is completely closed or only opened with a minimum lift. This exhaust gas flows only via the exhaust manifold 6 to the first turbocharger 7; the second turbocharger 9 is at a standstill or idling. The control valves of the second turbocharger 9 are closed: the "waste gate" valve 10, via which flow can bypass the exhaust gas turbocharger, and the check valve 11 are both closed in this operating state, so that the entire exhaust gas flow is routed exclusively to the first exhaust gas turbocharger 7. This means that it can be started up quickly and operated in the optimum operating state. The exhaust gas charged via it can be fed to the further combustion process; alternatively, it can be used for the particularly fast response of the cat 1-3, cat 4-6 catalyzers.

In this operating state, the second exhaust manifold 8 has no exhaust gas or only a very small amount of exhaust gas applied to it.

Exhaust manifolds 8 are connected—ideally close to the exhaust gas turbocharger—via an overflow valve 12 connecting the two exhaust manifolds 6 and 8 . The overflow valve 12 is provided with an overflow flap 13 in order to accelerate the startup of the exhaust gas turbocharger 9 which is idle or operated e.g. during acceleration processes. When the exhaust valve 4 is open and the exhaust valve 5 is still closed or only partially open, the overflow flap 13 of the overflow valve 12 in the exhaust manifold 8 can be opened with the "waste gate" valve 10 still closed and the check valve 11 also closed, so that the second exhaust gas turbocharger 9 can Exhaust manifold 6 applied to the exhaust manifold 8-run exhaust gas and is thus booted. The exhaust gas fed in to run up the second exhaust gas turbocharger 9 is fed to the exhaust gas charged by the turbocharger 7 downstream of the turbocharger and fed into the combustion process.

• Im Volllastbetrieb sind beide Auslassventile 4 und 5 mit Vollhub geöffnet; die Überströmklappe 13 des Überströmventils 12 ist geschlossen, so dass der Abgasstrom über die Auslassventile 4 ausschließlich über den Abgaskrümmer 6 dem ersten Abgasturbolader 7 und der Abgasstrom der Auslassventile 5 ausschließlich über den zweiten Abgaskrümmer 8 dem zweiten Abgasturbolader 9 zugeführt wird. In diesem Betriebszustand sind beide Abgasturbolader 7 bzw. 9 in vollem Betrieb. Für diesen Vollbetrieb ist das „Waste-Gate“-Ventil 10 beim geregelten Abgasturbolader 9 weiterhin geschlossen, während das Sperrventil 11 zur Abfuhr des aufgeladenen Gases voll geöffnet ist.

A third mode of operation is described below 4 described:

• In full-load operation, both exhaust valves 4 and 5 are open with full lift; the overflow flap 13 of the overflow valve 12 is closed, so that the exhaust gas flow via the outlet valves 4 is fed exclusively via the exhaust manifold 6 to the first exhaust gas turbocharger 7 and the exhaust gas flow from the outlet valves 5 is fed exclusively via the second exhaust manifold 8 to the second exhaust gas turbocharger 9. In this operating state, both exhaust gas turbochargers 7 and 9 are in full operation. For this full operation, the "waste gate" valve 10 in the regulated exhaust gas turbocharger 9 remains closed, while the check valve 11 for discharging the supercharged gas is fully open.

It goes without saying that depending on the position of the exhaust valves 4 or 5, the open or closed position of the overflow flap 13 of the overflow valve 12 and the open or closed position of the control valves 10 or 11 of the exhaust gas turbocharger 9 further operating states for exhaust gas charging can be adjusted.

In addition to the regulation of the exhaust gas turbocharger 9 via the valves 10 and 11, the exhaust gas turbocharger 7 can also be correspondingly regulated via valves.

According to the above description of the operating state based on the 2-4 for one cylinder group, the exhaust gas flow is controlled or regulated for the second cylinder group.

5 shows schematically the overflow valve 12 separating or connecting the exhaust manifold 6 or 8 when the overflow flap 13 is in the open position.

6 shows the arrangement of the overflow valve 12 on the exhaust manifolds 6 and 8.

Reference List

1

internal combustion engine

2

Cylinder group 1

3

Cylinder group 2

4, 4.1

outlet valve

5, 5.1

outlet valve

6, 6.1

exhaust manifold

7, 7.1

first exhaust gas turbocharger

8, 8.2

exhaust manifold

9, 9.1

second exhaust gas turbocharger

10

“Waste Gate” valve

11

check valve

12

overflow valve

13

overcurrent flap

Claims (4)

Internal combustion engine (1) with several cylinder groups (2, 3) each consisting of several cylinders and with several exhaust gas turbochargers (7, 7.1, 9, 9.1), a first cylinder group (2) having a first exhaust gas turbocharger (7) and a second exhaust gas turbocharger (9) assigned and wherein a first exhaust gas turbocharger (7.1) and a second exhaust gas turbocharger (9.1) are assigned to a second cylinder group (3), in such a way that the cylinder of the first cylinder group (2) from the first exhaust valves (4) and the cylinder from the first exhaust valves (4.1) Cylinders of the second cylinder group (3) via a respective first exhaust manifold (6, 6.1) of the respective cylinder group (2, 3) exhaust gas can be supplied to the respective first exhaust gas turbocharger (7, 7.1) of the respective cylinder group (2, 3) that from second exhaust valves (5) the cylinder of the first cylinder group (2) and from second exhaust valves (5.1) the cylinder of the second cylinder group (3) exhaust gas via a second exhaust manifold (8, 8.1) of the respective cylinder group (2, 3) Exhaust gas can be fed to the respective second exhaust gas turbocharger (9, 9.1) of the respective cylinder group (2, 3), the exhaust manifolds (6, 6.1, 8, 8.1) per cylinder group (2, 3) each having one exhaust gas turbocharger (7, 7.1, 9, 9.1) of the respective cylinder group (2, 3) can be connected, which can be acted upon in a controllable or regulatable manner by means of a respective overflow valve (12, 13) with the exhaust gas flow, characterized in that the respective overflow valve (12, 13) in the Exhaust manifolds (6, 6.1, 8, 8.1) of the respective cylinder group (2, 3) is arranged, with opening and closing of the overflow valves (12, 13) with opening and/or closing of control valves (10, 11) of the exhaust gas turbochargers ( 7, 7.1, 9, 9.1). internal combustion engine claim 1 , characterized in that the overflow valves (12, 13) for the controllable or regulatable inflow of the exhaust gas turbocharger(s) (7, 7.1, 9, 9.1) can be opened and/or closed. internal combustion engine claim 1 , characterized in that during part-load operation or in stationary operation or full-load operation of the internal combustion engine (1) in a lower speed range, the overflow valves (12, 13) for the exclusive loading of one of the exhaust gas turbochargers (7, 7.1, 9, 9.1) per cylinder group (2, 3 ) are closed. internal combustion engine claim 1 , characterized in that when the internal combustion engine (1) is operating under full load in a medium or upper speed range, the overflow valves (12, 13) can be opened to apply pressure to both turbochargers.

Images