DE202015104455U1 - Charged internal combustion engine with exhaust gas recirculation and flap - Google Patents

Abstract

A supercharged internal combustion engine with - an intake system (1) for supplying a charge air flow, - an exhaust gas discharge system for discharging exhaust gas, - at least one in the intake system (1) arranged compressor (2) with at least one in a housing (2c) on a rotatable shaft (2d) mounted impeller (2e) is equipped, - an exhaust gas recirculation (5) comprising a return line (5a), which branches off from the Abgasabführsystem and upstream of the at least one impeller (2e) to form a node (5b) in the intake system (1) opens, and - a flap (3) delimited circumferentially by an edge (3a), which is arranged in the intake system (1) at the junction (5b) and is pivotable about an axis (3b) running transversely to the fresh air flow in such a way that Flap (3) in a first end position with a front side (3 ') blocks the intake system (1) and the return line (5a) releases and in a second end position with a Rüc Side (3 '') the return line (5a) covered and the intake system (1) releases, characterized in that - the flap (3) is not flat, and - the flap (3) at least on the front side (3 ') at least has a deformation (4) as unevenness.

Description

• – einem Ansaugsystem zum Zuführen einer Ladeluftströmung,
• – einem Abgasabführsystem zum Abführen von Abgas,
• – mindestens einem im Ansaugsystem angeordneten Kompressor, der mit mindestens einem in einem Gehäuse auf einer drehbaren Welle gelagerten Laufrad ausgestattet ist,
• – einer Abgasrückführung umfassend eine Rückführleitung, die vom Abgasabführsystem abzweigt und stromaufwärts des mindestens einen Laufrades unter Ausbildung eines Knotenpunktes in das Ansaugsystem mündet, und
• – einer umfänglich von einem Rand begrenzten Klappe, die im Ansaugsystem am Knotenpunkt angeordnet ist und um eine quer zur Frischluftströmung verlaufende Achse in der Art verschwenkbar ist, dass die Klappe in einer ersten Endposition mit einer Vorderseite das Ansaugsystem versperrt und die Rückführleitung freigibt und in einer zweiten Endposition mit einer Rückseite die Rückführleitung verdeckt und das Ansaugsystem freigibt.

The invention relates to a supercharged internal combustion engine with

• An intake system for supplying a charge air flow,
• An exhaust gas removal system for removing exhaust gas,
• At least one compressor arranged in the intake system and equipped with at least one impeller mounted in a housing on a rotatable shaft,
• An exhaust gas recirculation system comprising a return line which branches off from the exhaust gas removal system and opens into the intake system upstream of the at least one impeller, forming a junction, and
• - A circumferentially bounded by an edge flap, which is arranged in the intake system at the node and is pivotable about an axis extending transversely to the fresh air flow in the way that the flap in a first end position with a front obstructs the intake and the return line releases and in one second end position with a back cover the return line and the intake system releases.

An internal combustion engine of the type mentioned is used as a motor vehicle drive. In the context of the present invention, the term internal combustion engine includes diesel engines and gasoline engines, but also hybrid internal combustion engines that use a hybrid combustion process, as well as hybrid drives, which in addition to the internal combustion engine include an electric motor that can be connected to the engine, which receives power from the internal combustion engine or as switchable auxiliary drive additionally delivers power.

In recent years, there has been a shift toward supercharged engines, with the economic importance of these engines for the automotive industry continuing to increase.

Charging is primarily a performance enhancement process in which the air needed for the engine combustion process is compressed, allowing each cylinder to be supplied with greater air mass per cycle. As a result, the fuel mass and thus the medium pressure can be increased.

The charge is a suitable means to increase the capacity of an internal combustion engine with unchanged displacement or to reduce the displacement at the same power. In any case, the charging leads to an increase in space performance and a lower power mass. If the displacement is reduced, then the load spectrum can be shifted to higher loads, where the specific fuel consumption is lower. By charging in combination with a suitable transmission design and a so-called downspeeding can be realized, in which also a lower specific fuel consumption can be achieved.

Charging thus supports the constant effort in the development of internal combustion engines to minimize fuel consumption, d. H. to improve the efficiency of the internal combustion engine.

Frequently, an exhaust gas turbocharger is used for the supercharging, in which a compressor and a turbine are arranged on the same shaft. The hot exhaust stream is supplied to the turbine and relaxes with energy release in the turbine, causing the shaft to rotate. The energy emitted by the exhaust gas flow to the turbine and finally to the shaft is used to drive the compressor, which is also arranged on the shaft. The compressor conveys and compresses the charge air supplied to it, whereby a charging of the cylinder is achieved. Advantageously, a charge air cooler is provided downstream of the compressor in the intake system, with which the compressed charge air is cooled before entering the at least one cylinder. The radiator lowers the temperature and thus increases the density of the charge air, so that the cooler to a better filling of the cylinder, d. H. contributes to a larger air mass. There is a compaction by cooling.

The advantage of an exhaust gas turbocharger in comparison to a mechanical supercharger is that an exhaust gas turbocharger uses the exhaust gas energy of the hot exhaust gases, while a mechanical supercharger obtains the energy required for its drive directly or indirectly from the internal combustion engine. In general, a mechanical connection for power transmission between the supercharger and the internal combustion engine is required.

The advantage of a mechanical supercharger over an exhaust-gas turbocharger is that the mechanical supercharger always generates and makes available the required boost pressure, regardless of the operating state of the internal combustion engine, in particular independently of the currently present rotational speed of the crankshaft. This applies in particular to a mechanical loader which can be driven by means of an electric machine.

In fact, according to the state of the art, it is difficult to increase the power by means of turbocharging in all engine speed ranges. It is observed a greater torque drop when falling below a certain speed. This torque drop becomes understandable when is taken into account that the boost pressure ratio depends on the turbine pressure ratio or the turbine power. If the engine speed is reduced, this leads to a smaller exhaust gas mass flow and thus to a smaller turbine pressure ratio or a smaller turbine power. Consequently, the boost pressure ratio also decreases toward lower speeds. This is synonymous with a torque drop.

The internal combustion engine, which is the subject of the present invention, has a compressor for charging, wherein in the context of the present invention the term compressor as well as mechanical superchargers and compressors of exhaust gas turbochargers are subsumed.

Another fundamental goal is to reduce pollutant emissions. In the solution of this task, the charge can also benefit. With targeted design of the charge namely benefits in efficiency and in the exhaust emissions can be achieved. In order to comply with future limits for pollutant emissions in addition to the charge but further internal engine measures required.

Thus, the exhaust gas recirculation serves to reduce nitrogen oxide raw emissions. The recirculation rate x _{AGR is} determined to be x _AGR = m _AGR / (m _AGR + m _{fresh air} ), where m _{AGR designates} the mass of recirculated exhaust gas and m _{fresh air} the fresh air supplied. Any oxygen or recirculated air returned via exhaust gas recirculation must be taken into account.

The supercharged internal combustion engine according to the invention is also equipped with an exhaust gas recirculation system, wherein the return line branching from the exhaust gas discharge system opens into the intake system upstream of the compressor, as is the case regularly with a low pressure EGR, with the exhaust gas at the intake side is returned, which has already flowed through arranged in the Abgasabführsystem turbine. For this purpose, the low-pressure EGR comprises a return line, which branches off downstream of the turbine from the Abgasabführsystem and preferably opens upstream of the compressor in the intake system.

The internal combustion engine, which is the subject of the present invention, further has a flap, which is arranged in the intake system at the junction. The flap can serve to adjust the amount of fresh air supplied via the intake system and at the same time meter the amount of exhaust gas recirculated via exhaust gas recirculation and is pivotable about an axis extending transversely to the fresh air flow such that in a first end position the front of the flap obstructs the intake system and at the same time the return line is released and in a second end position, the back of the flap covers the return line and at the same time the intake system is released. In the above sense, both obstructing and covering do not necessarily mean closing.

The transverse to the fresh air flow axis about which the flap is pivotable, does not have to be a figurative axis. Rather, this axis may be a virtual axis, the position of which may also have a small clearance with respect to the rest of the intake system, the storage being carried out in a different way.

In principle, efforts are made to shift the pumping limit of the compressor as far as possible to smaller charge air flows, in particular in the exhaust gas turbocharging. Then high boost pressure ratios can already be achieved with small compressor flows, whereby the torque characteristics in the lower speed range is significantly improved. The flow of the compressor comes with respect to a shift of the surge line of particular importance.

Against this background, it is the object of the present invention to provide a supercharged internal combustion engine according to the preamble of claim 1, with which the disadvantages known from the prior art are overcome and smaller charge air flows can be realized and compressed.

• – einem Ansaugsystem zum Zuführen einer Ladeluftströmung,
• – einem Abgasabführsystem zum Abführen von Abgas,
• – mindestens einem im Ansaugsystem angeordneten Kompressor, der mit mindestens einem in einem Gehäuse auf einer drehbaren Welle gelagerten Laufrad ausgestattet ist,
• – einer Abgasrückführung umfassend eine Rückführleitung, die vom Abgasabführsystem abzweigt und stromaufwärts des mindestens einen Laufrades unter Ausbildung eines Knotenpunktes in das Ansaugsystem mündet, und
• – einer umfänglich von einem Rand begrenzten Klappe, die im Ansaugsystem am Knotenpunkt angeordnet ist und um eine quer zur Frischluftströmung verlaufende Achse in der Art verschwenkbar ist, dass die Klappe in einer ersten Endposition mit einer Vorderseite das Ansaugsystem versperrt und die Rückführleitung freigibt und in einer zweiten Endposition mit einer Rückseite die Rückführleitung verdeckt und das Ansaugsystem freigibt, die dadurch gekennzeichnet ist, dass
• – die Klappe nicht eben ist, und
• – die Klappe zumindest an der Vorderseite mindestens eine Deformation als Unebenheit aufweist.

This problem is solved by a supercharged internal combustion engine

• An intake system for supplying a charge air flow,
• An exhaust gas removal system for removing exhaust gas,
• At least one compressor arranged in the intake system and equipped with at least one impeller mounted in a housing on a rotatable shaft,
• An exhaust gas recirculation system comprising a return line which branches off from the exhaust gas removal system and opens into the intake system upstream of the at least one impeller, forming a junction, and
• - A circumferentially bounded by an edge flap, which is arranged in the intake system at the node and is pivotable about an axis extending transversely to the fresh air flow in the way that the flap in a first end position with a front obstructs the intake and the return line releases and in one second end position with a rear cover the return line and the suction system releases, which is characterized in that
• - the flap is not level, and
• - The flap has at least on the front at least one deformation as unevenness.

The flap of the internal combustion engine according to the invention is not flat and like a conventional internal combustion engine, d. H. similar to a plate having a width and height which are many times the thickness. Rather, the flap according to the invention has a visually three-dimensional shape and thus a certain depth, this depth or the unevenness resulting from at least one deformation on the front side of the flap.

In order to form a flap according to the invention, it is also possible to use an originally planar flap which is deformed for the purpose of introducing at least one deformation. This procedure can also be advantageous in terms of retrofitting an internal combustion engine with a flap according to the invention.

Investigations have shown that the deformation of the flap has or has favorable aerodynamic effects. A substantially axial charge air flow or fresh air flow can with the help of the flap a speed component across the shaft of the compressor, d. H. a twist, to be forced. As a result, the surge limit of the compressor can be shifted towards smaller charge air flows, which is why higher boost pressure ratios are achieved even with small charge air flows. The torque characteristic of the supercharged internal combustion engine improves noticeably in the lower engine speed range.

Thereby, the object underlying the invention is achieved, namely provided a supercharged internal combustion engine, with which the disadvantages known from the prior art are overcome and smaller charge air flows can be realized and compressed.

Further advantageous embodiments of the internal combustion engine are discussed in connection with the subclaims.

Advantageous embodiments of the internal combustion engine, in which the axis is arranged near an edge portion of the flap. In this embodiment, the flap is similar to a door mounted laterally and pivotally, namely at one of its edges. This distinguishes the flap of the invention of centrally mounted shut-off elements or flaps such as a butterfly valve.

Embodiments of the internal combustion engine in which the axis is arranged near a wall section of the intake system are advantageous. The intake system regularly takes over the function of a frame with respect to the flap, d. H. framed the flap. As such, an embodiment in which the axis is located near an edge portion of the flap is also typically an embodiment in which the axis is located near a wall portion of the aspiration system. The essential advantage of both embodiments is that the flap is positioned close to the wall in the second end position, so that a completely free passage for the fresh air is created.

Embodiments of the internal combustion engine in which the at least one deformation of the flap comprises at least one bend are advantageous.

However, embodiments of the internal combustion engine in which the at least one deformation of the flap comprises at least one curvature are particularly advantageous. A vault, d. H. a rounded flap surface or flap front side is aerodynamically favorable and directs the fresh air turbulence low in the direction of the impeller. A kink, d. H. a sharp edge, however, causes pronounced turbulence in the intake fresh air flow. This is to be regarded as disadvantageous because of the pressure loss in the intake fresh air, but may also have advantages in terms of mixing the fresh air with the recirculated exhaust gas.

In this context, embodiments of the internal combustion engine in which at least one curvature is convex are advantageous.

Also advantageous in this connection are embodiments of the internal combustion engine in which at least one curvature is concave.

In the two above embodiments, the front of the flap serves as a reference plane, i. H. the determination in the individual case, whether a present curvature is curved inwards or outwards, is made starting from the front side, which is strictly assumed to be a virtually flat front side of the flap.

Embodiments of the internal combustion engine in which the at least one deformation on the front side of the flap faces the fresh air flow, at least in the first end position of the flap, are advantageous. Then the at least one deformation effectively protrudes into the fresh air flow.

Embodiments of the internal combustion engine are advantageous in which the at least one deformation detects an edge region of the flap which is arranged opposite the axis, or the at least one deformation is limited to this edge region of the flap. This is the edge area of the flap over which the fresh air flow passes and over which the flow is directed towards the impeller. In this respect, in particular, this section is suitable for a guiding function or the introduction of a swirl into a substantially axial fresh air flow. The edge of this area may also be referred to as the flap's trailing edge.

In this context, embodiments of the internal combustion engine are advantageous in which the at least one deformation on one side detects a Randeckbereich the flap or the at least one deformation is limited to this Randeckbereich the flap. One corner of the flap according to the invention is regularly a rounded corner. Deforming the flap on one side only facilitates the introduction of a velocity component across the shaft of the impeller into a substantially axial fresh air flow, i. H. the introduction of a twist.

Embodiments of the internal combustion engine in which the at least one deformation of the flap in the edge corner region gives a helically twisted shape are advantageous.

Embodiments of the internal combustion engine in which at least one exhaust-gas turbocharger is provided, which comprises a turbine arranged in the exhaust-gas removal system and a compressor arranged in the intake system, are advantageous. With regard to the above embodiment, reference is made to the statements already made in connection with the exhaust gas turbocharger, in particular the advantages that have been pointed out.

Therefore, embodiments of the internal combustion engine in which the at least one compressor is the compressor of the at least one exhaust gas turbocharger are also advantageous in this connection.

Embodiments of the internal combustion engine in which the at least one compressor is a radial compressor are advantageous. This embodiment allows a dense packaging in terms of charging. The compressor housing can be designed as a spiral or worm housing. In an exhaust gas turbocharger, the deflection of the charge air flow in the compressor of the exhaust gas turbocharger can advantageously be used to guide the compressed charge air to the inlet side by the shortest route from the outlet side, on which the turbine of the exhaust gas turbocharger is frequently arranged.

In this context, embodiments of the internal combustion engine in which the turbine of the at least one exhaust-gas turbocharger is a radial turbine are advantageous. This embodiment also allows a tight packaging of the exhaust gas turbocharger and thus the overall charge.

Unlike the turbines, compressors or compressors are defined by their outflow. A radial compressor or radial compressor is thus a compressor or compressor whose outflow from the blades takes place substantially radially. In the context of the present invention, essentially radial means that the velocity component in the radial direction is greater than the axial velocity component.

But can also be advantageous embodiments of the internal combustion engine, in which the compressor is designed in Axialbauweise. The outflow from the impeller blades of an axial compressor takes place substantially axially.

Advantageous embodiments of the internal combustion engine, in which the at least one compressor has an inlet region which is coaxial with the shaft of the at least one impeller and is formed so that the flow of the charge air to the at least one impeller is substantially axially.

In an axial flow of the compressor or compressor often eliminates a deflection or change in direction of the charge air flow in the intake upstream of the at least one impeller, whereby unnecessary pressure losses in the charge air flow due to flow deflection can be avoided and the pressure of the charge air is increased at the inlet to the compressor. The lack of change in direction also reduces the contact of the exhaust gas or the charge air with the inner wall of the intake system or with the inner wall of the compressor housing and thus reduces the heat transfer and condensation.

When using at least one exhaust gas turbocharger embodiments of the internal combustion engine are advantageous in which the return line branches off from the Abgasabführsystem downstream of the turbine of the at least one exhaust gas turbocharger according to a low-pressure EGR.

In contrast to a high pressure EGR which introduces exhaust gas taken from the exhaust gas removal system upstream of the turbine into the intake system, preferably downstream of the compressor, exhaust gas is generated at a low pressure EGR returned the inlet side, which has already flowed through the turbine. For this purpose, the low-pressure EGR comprises a return line, which branches off downstream of the turbine from the Abgasabführsystem and opens upstream of the compressor in the intake system.

The main advantage of the low-pressure EGR compared with the high-pressure EGR is that the exhaust gas flow introduced into the turbine is not reduced by the amount of recirculated exhaust gas in the case of exhaust gas recirculation. It is always the entire exhaust gas flow to the turbine to generate a sufficiently high boost pressure available.

The exhaust gas, which is returned to the inlet side by means of low-pressure EGR and is preferably cooled, is mixed with fresh air upstream of the compressor. The thus generated mixture of fresh air and recirculated exhaust gas forms the charge air or combustion air, which is supplied to the compressor and compressed.

It is harmless that exhaust gas is passed through the compressor in the context of low-pressure EGR, since exhaust gas is used regularly, which downstream of the turbine exhaust after-treatment, in particular in a particulate filter was subjected. Deposits in the compressor, which change the geometry of the compressor, in particular the flow cross-sections, and thus worsen the efficiency of the compressor, are therefore not to be feared.

Embodiments of the internal combustion engine in which downstream of the turbine of the at least one exhaust-gas turbocharger a first shut-off element in the exhaust-gas removal system is arranged are advantageous, wherein the return line between the turbine and the shut-off element branches off from the exhaust-gas removal system. The first shut-off element can be used to increase the exhaust gas pressure upstream of the shut-off element in the exhaust gas discharge system, and thus be used for an increase in the pressure gradient between the Abgasabführsystem and the intake system. This offers particular advantages at high recirculation rates, which require a larger pressure gradient.

Embodiments of the internal combustion engine in which upstream of the node a second shut-off element is arranged in the intake system are advantageous. The second shut-off element is used on the inlet side to reduce the pressure in the intake system and thus - as the first shut-off - contribute to an increase in the pressure gradient between the Abgasabführsystem and the intake system.

In this context, embodiments of the internal combustion engine in which the first and / or the second shut-off element is a pivotable or rotatable flap are advantageous.

Embodiments of the internal combustion engine can be advantageous in which the return line is equipped with a valve which comprises an axially displaceable valve body, which is connected to the flap and mechanically coupled in this way, wherein pivoting of the flap causes a displacement of the valve body. Consequently, the flap can serve as actuator for the valve or the valve as actuator for the flap.

All variants of the above embodiment has in common that the flap is used only for adjusting the amount of air supplied via the intake system and not the dosage of the recirculated exhaust gas amount. The latter is accomplished with the valve, which is in the return line and serves as an EGR valve.

Advantageous embodiments of the internal combustion engine, in which the node is formed and arranged in the vicinity of the at least one impeller to form a distance .DELTA. A compressor close arrangement of the node shortens the distance of the hot recirculated exhaust gas from the point of introduction into the intake system to the at least one impeller, so that the time in which condensate droplets can form in the free charge air flow, is reduced. A formation of condensate droplets is thus counteracted. In addition, a swirl introduced into the flow using the flap is still effective upon entry of the charge air into the impeller, d. H. still pronounced. This is also intended and therefore advantageous.

In this context, embodiments of the internal combustion engine are advantageous in which for the distance Δ applies: Δ ≤ 2.0D _V and Δ ≤ 1.5D _V , where D _V indicates the diameter of the at least one impeller. According to advantageous embodiments, which applies to the distance Δ: Δ ≤ 1.0D _V, preferably 0.75D Δ ≤ _V.

For operating a supercharged internal combustion engine of the foregoing type wherein the at least one compressor has an inlet area coaxial with and extending from the shaft of the at least one impeller, a substantially axial fresh air flow through the flap becomes a velocity component transverse to the shaft of the at least one Impeller forced.

In the following the invention is based on an embodiment according to the 1a and 1b described in more detail. Hereby shows:

1a schematically the arranged in the intake compressor of a first embodiment of the internal combustion engine together with exhaust gas recirculation, partially cut, and

1b schematically the compressor according to 1a in a perspective view overlooking the impeller, partially cut.

1a schematically shows the intake system 1 arranged compressor 2 a first embodiment of the internal combustion engine together with exhaust gas recirculation 5 , partially cut.

For supplying the charge air to the cylinders, the internal combustion engine has an intake system 1 and for the purpose of charging the cylinders, there is provided an exhaust gas turbocharger having a turbine (not shown) disposed in the exhaust gas discharge system and one in the intake system 1 arranged compressor 2 includes. The compressor 2 is a centrifugal compressor 2 B in its case 2c an impeller 2e is mounted on a rotatable shaft. The shaft of the impeller 2e lies in the plane of the 1a and runs horizontally.

The compressor 2 the exhaust gas turbocharger has an inlet area 2a on, coaxial with the shaft of the compressor 2 runs and is formed so that the section of the intake system 1 upstream of the compressor 2 has no direction changes and the flow of charge air to the compressor 2 the exhaust gas turbocharger or its impeller 2e essentially axially.

The internal combustion engine is further equipped with exhaust gas recirculation 5 equipped, which is a return line 5a which branches off the exhaust gas removal system downstream of the turbine and upstream of the compressor 2 and the compressor impeller 2e forming a node 5b into the intake system 1 empties. The node 5b is present to form a small distance Δ near the compressor 2 arranged, whereby a condensation is counteracted.

To set the amount of recirculated exhaust gas is an EGR valve 6 which is in the return line 5a stuck, thus at the junction 5b is arranged and an axially displaceable valve body 6a Includes, with a pivoting flap 3 connected and in this way mechanically with this flap 3 is coupled.

The in the intake system 1 at the junction 5b arranged flap 3 becomes perimeter of a border 3a limited, with storage 3c the flap 3 in the intake system 1 using a pivot axis 3b he follows. The axis running transversely to the fresh air flow 3b to which the flap 3 is pivotable, is perpendicular to the plane of the drawing. The present is this axis 3b near a brim of the flap 3 and near a wall portion of the intake system 1 arranged, leaving the flap 3 similar to a door is mounted laterally.

1a shows the flap 3 in two different pivot positions. In a first end position the flap blocks 3 with her front 3 ' the intake system 1 , In a second end position, the back covers up 3'' the flap 3 the return line 5a the exhaust gas recirculation 5 whereas the intake system 1 is released.

A pivoting of the flap 3 is with a displacement of the valve body 6a of the EGR valve 6 connected, with the flap 3 just setting the via intake system 1 supplied amount of air is used and not the dosage of the recirculated exhaust gas amount. The latter is served by the EGR valve 6 ,

The flap 3 is not flat, but faces the front 3 ' a deformation 4 , ie a bump on. This is the flap 3 as deformation 4 a convex curvature 4a on, the fresh air flow in the first end position of the flap 3 and opposes. The vault 4a detects a border area of the flap 3 , the opposite of the axis 3b is arranged.

1b schematically shows the compressor 2 according to 1a in a perspective view overlooking the impeller 2e , partially cut. It should only be supplementary to 1a For that reason, reference is made to FIG 1a , The same reference numerals have been used for the same components.

As 1b can be seen, recorded on the front 3 ' the flap 3 intended vaulting 4a on one side a Randeckbereich 7 the flap 3 , The vault 4a is present on the left Randeckbereich 7 the flap 3 limited, which is indicated by the black coloring. At the corner 7 the flap 3 it is a rounded corner 7 , For introducing a velocity component across the shaft 2d of the impeller 2e is it expedient to shut up 3 - As in the present case - only to deform on one side.

LIST OF REFERENCE NUMBERS

1

 intake system

2

 Compressor, compressor of the turbocharger

2a

 Entry region of the compressor or the compressor of the exhaust gas turbocharger

2 B

 Radial compressor, radial compressor

2c

 Housing of the compressor or the compressor

2d

 Shaft of compressor or compressor

2e

 Impeller of the compressor or the compressor

3

 flap

3 '

 Front of the flap

3''

 Rear of the flap

3a

 Edge of the flap

3b

 Swivel axis of the flap

3c

 Storage of the flap

4

 deformation

4a

 bulge

5

 Exhaust gas recirculation

5a

 Return line

5b

 junction

6

 AGR valve

6a

 valve body

7

 Randeckbereich of the flap, corner

Δ

 Distance of the node to the impeller

AGR

 Exhaust gas recirculation

D _V

 Diameter of the at least one impeller

m _AGR

 Mass of recirculated exhaust gas

_{Fresh air}

 Mass of fresh air supplied

x _AGR

 Exhaust gas recirculation rate

Claims (18)

Charged internal combustion engine with - an intake system ( 1 ) for supplying a charge air flow, - an exhaust gas removal system for removing exhaust gas, - at least one in the intake system ( 1 ) arranged compressor ( 2 ) with at least one in a housing ( 2c ) on a rotatable shaft ( 2d ) mounted impeller ( 2e ), - exhaust gas recirculation ( 5 ) comprising a return line ( 5a ), which branches off from the exhaust gas removal system and upstream of the at least one impeller ( 2e ) forming a node ( 5b ) into the intake system ( 1 ), and - one perimeter of one edge ( 3a ) limited flap ( 3 ) in the intake system ( 1 ) at the junction ( 5b ) is arranged and about an axis extending transversely to the fresh air flow ( 3b ) is pivotable in the way that the flap ( 3 ) in a first end position with a front side ( 3 ' ) the intake system ( 1 ) and the return line ( 5a ) and in a second end position with a rear side ( 3'' ) the return line ( 5a ) and the intake system ( 1 ), characterized in that - the flap ( 3 ) is not even, and - the flap ( 3 ) at least on the front side ( 3 ' ) at least one deformation ( 4 ) as unevenness. Supercharged internal combustion engine according to claim 1, characterized in that the axle ( 3b ) near an edge portion of the flap ( 3 ) is arranged. Supercharged internal combustion engine according to claim 1 or 2, characterized in that the axis ( 3b ) near a wall section of the intake system ( 1 ) is arranged. Supercharged internal combustion engine according to one of the preceding claims, characterized in that the at least one deformation ( 4 ) the flap ( 3 ) comprises at least one kink. Supercharged internal combustion engine according to one of the preceding claims, characterized in that the at least one deformation ( 4 ) the flap ( 3 ) at least one vault ( 4a ). Supercharged internal combustion engine according to claim 5, characterized in that at least one curvature ( 4a ) is convex. Supercharged internal combustion engine according to claim 5, characterized in that at least one curvature ( 4a ) is concave. Supercharged internal combustion engine according to one of the preceding claims, characterized in that the at least one deformation ( 4 ) on the front side ( 3 ' ) the flap ( 3 ) the charge air flow at least in the first end position of the flap ( 3 ) and opposes. Supercharged internal combustion engine according to one of the preceding claims, characterized in that the at least one deformation ( 4 ) an edge region of the flap ( 3 ), which is opposite the axis ( 3b ) is arranged. Supercharged internal combustion engine according to claim 9, characterized in that the at least one deformation ( 4 ) one side a Randeckbereich ( 7 ) the flap ( 3 ) detected. Supercharged internal combustion engine according to claim 10, characterized in that the at least one deformation ( 4 ) the flap ( 3 ) in the edge corner region ( 7 ) gives a helically twisted shape. Supercharged internal combustion engine according to one of the preceding claims, characterized in that at least one exhaust-gas turbocharger is provided which has a turbine arranged in the exhaust-gas removal system and one in the intake system ( 1 ) arranged compressors ( 2 ). Supercharged internal combustion engine according to claim 12, characterized in that the at least one compressor ( 2 ) of the compressor ( 2 ) of the at least one exhaust gas turbocharger. Supercharged internal combustion engine according to one of the preceding claims, characterized in that the at least one compressor ( 2 ) a radial compressor ( 2 B ). Supercharged internal combustion engine according to one of the preceding claims, characterized in that the at least one compressor ( 2 ) an entrance area ( 2a ) coaxial with the shaft ( 2d ) of the at least one impeller ( 2e ) and is formed so that the flow of the charge air to the at least one impeller ( 2e ) is effected substantially axially. Supercharged internal combustion engine according to one of claims 12 to 14, characterized in that the return line ( 5a ) branches off downstream of the turbine of the at least one exhaust gas turbocharger from Abgasabführsystem. Supercharged internal combustion engine according to one of the preceding claims, characterized in that the return line ( 5a ) with a valve ( 6 ), which has an axially displaceable valve body ( 6a ), which with the flap ( 3 ) and is mechanically coupled in this way, wherein a pivoting of the flap ( 3 ) a displacement of the valve body ( 6a ) conditionally. Supercharged internal combustion engine according to one of the preceding claims, characterized in that the node ( 5b ) in the vicinity of the at least one impeller ( 2e ) is formed and arranged to form a distance Δ.

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