DE102006009298A1 - Internal combustion engine with an exhaust gas turbocharger - Google Patents

Abstract

An internal combustion engine has an exhaust gas turbocharger, which comprises an exhaust gas turbine (3) in the exhaust line (4) and a compressor (1) in the intake tract (2), wherein the exhaust gas turbine (3) has two separate turbine floods (6, 7) via which the Turbine wheel exhaust gas can be supplied. The mass flow through the two turbine floods (6, 7) is adjustable by means of a switching device (40) which has a locking flap (45) which can pivot about an axis of rotation (46) in a switch housing (41) with two wings (45a, 45b) of at least the same length. has on both sides of the axis of rotation (46).

Description

The The invention relates to an internal combustion engine with an exhaust gas turbocharger according to the preamble of claim 1.

In the DE 103 57 925 A1 an internal combustion engine is described with an exhaust gas turbocharger, the exhaust gas turbine in the exhaust line two separate turbine flows of different sizes, via which the turbine of the exhaust gas turbine each exhaust gas can be supplied. Each of the two turbine floods is supplied via an exhaust pipe with exhaust gas, which is in each case fluidly connected to a cylinder bank of the internal combustion engine. Upstream of the exhaust gas turbine, the two exhaust pipes are mutually connected via a connecting line arranged therein, adjustable check valve, moreover, a further adjustable check valve is arranged in the exhaust pipe for the larger exhaust gas flow. Depending on the position of the check valves, the mass flows through the exhaust pipes and the associated turbine floods can be kept separate, so that a flow equalization between the exhaust pipes or between the exhaust gas is not possible, or it is the entire exhaust gas both banks led to the smaller flow tide or it the exhaust gas from both cylinder banks is supplied with equal pressure to both the smaller and the larger turbine tide.

by virtue of the high, caused by the engine pressure pulsations in the exhaust pipes arise on the check valves acting gas forces, the unwanted changes the valve position can result. The check valves must therefore be designed so that by pressure pulsations resulting gas forces no unwanted adjustments cause.

Of the Invention is based on the object with simple constructive activities a supercharged internal combustion engine, the exhaust gas turbine double-flow is designed to form in that pressure pulsations in the exhaust system no unwanted setting changes result in the mass flows to be supplied to the exhaust gas flows. This should expedient means a compact design to be realized.

These Task is according to the invention with the Characteristics of claim 1 solved. The dependent claims give expedient further education at.

According to the invention, it is provided that the switching device, over to adjust the mass flow through the two turbine floods is, one in a switch housing pivotally mounted blocking flap, the two at least equal long flap wings on both sides of the axis of rotation of the blocking flap has. This trapdoor is rotatably mounted in a connecting space in the switch housing, on the one hand with the two exhaust pipes and on the other hand with the two turbine floods the exhaust gas turbine communicates. about the two exhaust pipes becomes the exhaust gas of the cylinder banks of the internal combustion engine directed into the switching device and from there depending on the position the butterfly valve of one of the turbine floods or two turbine floods fed. Possible on the one hand is a separate supply of exhaust gas each exhaust pipe in the associated Turbine flood without transfer in the other exhaust pipe or turbine flood or blocking an exhaust gas flow and supply of the entire exhaust gas both cylinder banks in only a turbine flood, in the latter case, the supply of the entire Exhaust gas in each of the two turbine floods is eligible. Finally is in an intermediate position of the blocking flap also a pressure compensation between the two exhaust pipes and accordingly the supply Exhaust gas in every turbine flood under the same pressure possible.

by virtue of the special version the locking flap with the two at least approximately equally long flap wings this side and beyond the axis of rotation of the barrier flap, a gas force compensation achieved that over brought the exhaust pipes zoom and pressurized exhaust gas, the two wings in the same way around the Rotary axis of the blocking flap subjected to force, so that no resulting Torque arises. In the connection space in the switch housing, in which the locking flap is pivotally mounted, mixes the above the mouths brought the exhaust pipes Exhaust gas, leaving on the orifices the exhaust pipes facing side of the blocking flap a uniform Pressure over the surface the blocking flap rests. This uniform pressure prevents the Generation of resulting torques. Also with pressure pulsations in the exhaust system there is a uniform application of force the blocking flap. This has the consequence that the blocking flap itself regardless of any pressure pulsations in the exhaust system always in equilibrium and maintains its current position. Therefore, if necessary to a surveillance the damper position can be dispensed with, as well as the risk of leakage considerably reduced. These advantages are achieved with a constructive simply designed and compact design.

The Blocking flap is advantageously designed as a rotary valve, the has a circumferential bearing in the switch housing. A shaft bearing in the region of the axis of rotation can be provided, but is the rotary valve not condition. about an axle-side shaft but can advantageously the adjusting movement of a initiated on the locking flap actuator can be initiated.

The orifices the exhaust pipes on the one hand and the channels to the turbine floods on the other are located advantageously on opposite sides in the connection space in the switch housing. The exhaust pipes and the channels the exhaust fumes are each about partitions separated, which are located diagonally in the switch housing. Based on these diagonally opposite Position the exhaust pipes and the channels of the exhaust gas flows are fluidic Completely separated when the blocking flap in one of the end faces of the partitions connecting Position is. At the same time, one of the two partitions, preferably the separating wall arranged between the turbine floods, expand towards the connecting space anvil and the connecting space part of a circle limit, whereby a support and guide surface is formed for the locking flap. About the Separating function thus has the partition so also one Bearing and guiding function for the Blocking flap.

According to one advantageous development is provided that the blocking flap of two axially spaced, firmly connected to the blocking flap cover plates is framed for a flow density Seal the connection space in the axial direction. The cover disks make sidewalls a flow channel with the blocking flap, wherein the blocking flap the cover discs connects and a third, the flow channel limiting side forms. On the opposite side of the barrier flap is the flow channel open and communicates depending on the rotational position of the blocking flap with the mouth openings both of the two opening into the connecting space exhaust pipes as well the branching, the turbine floods associated channels. On the outer surface of the cover plates can additional Seal or piston rings may be arranged, which seal in the axial direction guarantee and at the same time the rotatability of the housing side storage of the cover plates to ensure.

The Internal combustion engine is advantageous with an exhaust gas recirculation device equipped, one of the two exhaust pipes with the intake the internal combustion engine connects. Especially in the execution with two different sizes Turbine flooding becomes the exhaust pipe of the smaller turbine tide with the return line coupled, which has the advantage that when blocking the larger exhaust gas flow the entire exhaust of the engine of the smaller exhaust gas flow supplied and there is a heightened Exhaust back pressure is generated, the exhaust gas recirculation in the direction of intake supported. In a further advantageous embodiment, the exhaust gas turbine with variable turbine geometry for variable adjustment of the configured effective turbine inlet cross-section, whereby a additional Degree of freedom to regulate the exhaust back pressure is given.

Finally, can be it useful to bypass the exhaust gas turbine by means of a bypass, which is an adjustable bypass valve having. The blowoff over The bypass ensures, on the one hand, that the exhaust gas turbine is not overloaded On the other hand, this gives a further degree of freedom over which State and characteristics of the Internal combustion engine or the units of the internal combustion engine are affected.

Further Advantages and expedient designs are the further claims, the figure description and the drawings. Show it:

1 a schematic representation of a supercharged internal combustion engine with a dual-flow exhaust gas turbine, the exhaust gas mass flows are controllable in the turbine flows of the exhaust gas turbine via a switching device,

2 the switching device for controlling the mass flows into the turbine floods in an enlarged sectional view,

3 the blocking flap of the switching device in a sectional view along section line III-III 2 ,

In the 1 with reference number 100 designated internal combustion engine, which is a diesel engine or a gasoline engine is with an exhaust gas turbocharger 20 equipped with a compressor 1 in the intake tract 2 and an exhaust gas turbine 3 in the exhaust system 4 comprising, wherein the compressor wheel and the turbine wheel via a shaft 5 are rotationally coupled. The exhaust gas turbine 3 is twin-flow and has a smaller turbine tide 6 and a bigger turbine flood 7 , where the turbine floods 6 and 7 differ in flow cross-section. Over both turbine floods 6 and 7 is the turbine exhaust gas from the exhaust system 4 the internal combustion engine 100 fed. Furthermore, the exhaust gas turbine 3 with a variable turbine geometry 8th provided over which the effective turbine inlet cross section between a minimum storage position and a maximum opening position is variably adjustable.

The two turbine floods 6 and 7 are over exhaust pipes 22 and 23 the exhaust line 4 with the exhaust manifolds 30 respectively. 31 each of a cylinder bank 10 respectively. 11 the internal combustion engine 100 connected. In the exhaust pipes 22 and 23 there is a common switching device 40 , about which the exhaust gas mass flow into each turbine tide 6 respectively. 7 is controllable. The pipe sections in the exhaust line obligations 22 and 23 upstream of the switching device 40 are with the reference numerals 35 and 36 Mistake.

Downstream of the switching device 40 branches off the exhaust system 4 a bypass 50 in which an adjustable bypass valve 48 is integrated. The bypass 50 includes a first bypass line 51 coming from the exhaust pipe 22 the smaller turbine tide 6 branches and into the bypass valve 48 opens, and a second bypass line 52 , which in a similar way from the exhaust pipe 23 the larger turbine tide 7 Branched and also in the bypass valve 48 empties. About another bypass line 53 coming from the bypass valve 48 branched and downstream of the exhaust gas turbine 3 in the exhaust system 4 opens the bypass 50 completed.

The internal combustion engine 100 is also provided with an exhaust gas recirculation device, which is a return line 16 between the exhaust line 4 and the intake tract 2 , one in the return line 16 arranged exhaust gas cooler 15 as well as a unidirectional and appropriately adjustable return valve 17 includes. The return line 16 branches in the flow path between the switching device 40 and the exhaust gas turbine 3 from the exhaust pipe 22 the smaller turbine tide 6 and flows downstream of a charge air cooler 14 in the intake tract 2 ,

All units of the internal combustion engine are in response to state and parameters via control signals of a control and control unit 18 set. This concerns in particular the switching device 40 , the bypass valve 48 , the variable turbine geometry 8th and the return valve 17 ,

2 shows the switching device 40 , about which the mass flows into the turbine floods 6 and 7 are controllable, on average. In a switch housing 41 the switching device 40 there is a connection room 42 , who the opening into the switch housing line sections 35 and 36 the exhaust pipes with channels 43 and 44 connects that over other line sections with the turbine floods 6 respectively. 7 are connected. In the connection room 42 is a blocking flap 45 around a rotation axis 46 pivotally mounted, wherein the axis of rotation 46 centrally through the middle of the trapdoor 45 runs, such that the same size flap wings 45a and 45b the blocking flap 45 on both sides of the axis of rotation 46 extend. About the current rotational position of the blocking flap 45 is the mass flow supply to the turbine floods 6 and 7 adjustable. The blocking flap 45 is enclosed between two axially spaced cover plates, of which in 2 a cover disk 62 with circumferentially arranged sealing ring 64 is shown.

The butterfly valve designed as a rotary valve 45 is over the cover disk 62 and the further, axially spaced cover plate 63 ( 3 ) in the switch housing 41 stored circumferentially. An ambossally widening partition 61 between the channels 43 and 44 in the switch housing has a part-circular support surface on which the cover plates 62 and 63 support.

The partition 61 Diagonally opposite is another, narrow tapered partition 60 in the switch housing, which are the channels for the line sections 35 and 36 separated. Side of the partition 60 become the mouths of the channels for the pipe sections 35 and 36 bounded by wall portions of the switching housing in the way that contact points A and B in contact with the radially outer end faces of the locking flap 45 can reach. In 2 is an angular position for the blocking flap 45 located in the radially outer end face of the wing 45b the blocking flap bears against the contact point B which is located on a side wall which forms the channel for the line section 36 limited. In this angular position of the blocking flap 45 is an inflow of exhaust gas over both the conduit section 35 as well as over the line section 36 possible. The incoming exhaust gas mass flows are as shown by the solid arrows in the channel 43 initiated, with the smaller turbine tide 6 communicated. The second channel 44 in the switch housing 41 is on the other hand from the blocking flap 45 shut off, leaving the larger turbine tide 7 no exhaust gas is supplied. In a similar way, the channel 43 and the turbine tide 6 shut off and all the exhaust gas through the channel 44 into the larger flow tide 7 passed when the blocking flap 45 is in an angular position in which one of the radially outer end faces of the blocking flap bears against the contact point A.

Is the blocking flap 45 in contrast, in a vertical position, in which the end face of the partition 60 from the radially outer end face of a wing 45a or 45b the blocking flap 45 is contacted, so are the channels in the switch housing 41 completely separated, so that the exhaust gas mass flows over the the pipe sections 35 and 36 associated channels are initiated, not be merged and in each case in the assigned channels 43 respectively. 44 continue to flow. This case corresponds to a flow separation of the turbine floods 6 and 7 ,

In an intermediate position of the blocking flap 45 either between the top of the dividing wall 60 and the contact point A or in an intermediate position between the partition 60 and the contact point B - ie in each case in the middle of the mouth opening of the channel for the line section 35 or the channel for the line section 36 - finds one Mixing the zoomed exhaust gas mass flows instead, so that a pressure equalization between the mass flows is achieved. At the same time, both are outgoing channels 43 and 44 open, so that also the respective turbine floods 6 and 7 the same pressure is supplied.

The sectional view to 3 can be seen that the locking flap 45 between the axially spaced shrouds 62 and 63 is bordered, each having on its outer side a sealing ring 64 respectively. 65 have, whereby the space between the cover plates fluid-tight with respect to the switch housing 41 is sealed. The composite of cover disks 62 and 63 with shut-off flap 45 is on a wave 66 rotatable in the switch housing 41 stored, wherein via the shaft 66 to be applied via an actuator actuating movement to the blocking flap 45 is initiated.

Claims (14)

Internal combustion engine with an exhaust gas turbocharger having an exhaust gas turbine ( 3 ) in the exhaust line ( 4 ) and a compressor ( 1 ) in the intake tract ( 2 ), wherein the exhaust gas turbine ( 3 ) two separate turbine floods ( 6 . 7 ), via which the turbine wheel exhaust gas can be fed, and the mass flow through the two turbine floods ( 6 . 7 ) via a switching device ( 40 ) is adjustable, characterized in that the switching device ( 40 ) in a switch housing ( 41 ) one about a rotation axis ( 46 ) pivotable blocking flap ( 45 ) with two at least approximately equally long wings ( 45a . 45b ) on both sides of the axis of rotation ( 46 ), wherein the blocking flap ( 45 ) in a connection room ( 42 ) in the switch housing ( 41 ) and the connection space ( 42 ) with both turbine flows ( 6 . 7 ) of the exhaust gas turbine ( 3 ) as well as with two exhaust pipes ( 22 . 23 ), each of a cylinder bank ( 10 respectively. 11 ) of the internal combustion engine ( 100 ) assigned. Internal combustion engine according to claim 1, characterized in that in the connecting space ( 42 ) in the switch housing ( 41 ) each have a partition wall ( 60 ) between channels ( 43 . 44 ) of the exhaust pipes ( 22 . 23 ) and between channels ( 43 . 44 ) of the turbine floods ( 6 . 7 ) and that the partitions ( 60 . 61 ) diagonally opposite each other in the switch housing ( 41 ) are located. Internal combustion engine according to claim 2, characterized in that the turbine floods ( 6 . 7 ) associated partition ( 61 ) to the connection room ( 42 ) extended anvil-shaped and the connection space ( 42 ) Partially limited. Internal combustion engine according to claim 2 or 3, characterized in that the side areas of the part-circular extension of the turbine floods ( 6 . 7 ) associated partition ( 61 ) outer boundary walls of the exhaust pipes ( 22 . 23 ) associated channels ( 43 . 44 ) are diagonally opposite each other. Internal combustion engine according to one of claims 2 to 4, characterized in that the exhaust pipes ( 22 . 23 ) associated partition ( 61 ) to the connection room ( 42 ) is narrow towards. Internal combustion engine according to one of claims 1 to 5, characterized in that the pivotable blocking flap ( 45 ) is designed as a rotary valve with circumferential bearing. Internal combustion engine according to one of claims 1 to 6, characterized in that the blocking flap ( 45 ) of two axially spaced, fixedly connected to the blocking flap cover plates ( 62 . 63 ) is enclosed in the switch housing ( 41 ) are rotatably mounted. Internal combustion engine according to claim 7, characterized in that on the outside of the cover discs ( 62 . 63 ) Sealing rings ( 64 . 65 ) are arranged. Internal combustion engine according to one of claims 1 to 8, characterized in that the switching device ( 40 ) in the exhaust manifold ( 30 . 31 ) is integrated. Internal combustion engine according to one of claims 1 to 8, characterized in that the switching device ( 40 ) in the exhaust gas turbine ( 3 ) is integrated. Internal combustion engine according to one of claims 1 to 10, characterized in that the turbine floods ( 6 . 7 ) are formed differently sized with different flow cross sections. Internal combustion engine according to one of claims 1 to 11, characterized in that an exhaust gas recirculation device is provided, which is an exhaust pipe ( 22 . 23 ), a turbine torrent ( 6 . 7 ), with the intake tract ( 2 ) connects. Internal combustion engine according to one of claims 1 to 12, characterized in that the exhaust gas turbine ( 3 ) bridging bypass ( 50 ) with adjustable bypass valve ( 51 ) is provided. Internal combustion engine according to one of claims 1 to 13, characterized in that the exhaust gas turbine ( 3 ) with variable turbine geometry ( 8th ) is equipped for variable adjustment of the effective turbine inlet cross-section.