DE102010021926A1 - Internal combustion engine - Google Patents

Abstract

The invention relates to an internal combustion engine (25) with at least one exhaust gas recirculation line (16), by means of which exhaust gas from the internal combustion engine (25) can be returned from an exhaust gas side (52) to an air side (54) of the internal combustion engine (25), and with a turbine ( 58) having exhaust gas turbocharger (56), which comprises a turbine housing (10) in which a turbine wheel (18) of the turbine (58) is accommodated, and which has at least one spiral duct (12, 14) through which exhaust gas from the internal combustion engine (25) can flow , via which the exhaust gas can be fed to the turbine wheel (18), an adjusting device (20) of the turbine (58) being provided, by means of which at least one nozzle cross-section (AR) of the spiral channel (12, 14) can be adjusted, whereby by means of the adjusting device ( 20) the nozzle cross section (AR) of the spiral channel (12, 14) and a flow cross section (AAGR) of the return line (16) can be set together.

Description

The invention relates to an internal combustion engine specified in the preamble of claim 1. Art.

From the DE 10 2008 039 085 A1 An internal combustion engine for a motor vehicle with an exhaust gas turbocharger is known, which comprises a compressor in an intake tract of the internal combustion engine and a turbine in an exhaust gas tract of the internal combustion engine. In this case, the turbine has a turbine housing which comprises a spiral duct coupled to an exhaust pipe of the exhaust gas system and a turbine wheel, which is arranged within a receiving space of the turbine housing and for driving a compressor wheel of the compressor connected to the turbine wheel via a shaft with gas that can be guided through the spiral duct the internal combustion engine can be acted upon. The turbine comprises an adjusting device, by means of which a spiral inlet cross section of the spiral channel and a nozzle cross section of the spiral channel to the receiving space are jointly adjustable. The spiral channel can be formed as a partial spiral with a wrap angle between 350 ° and 30 °.

This internal combustion engine has further potential to further reduce its fuel consumption.

It is therefore an object of the present invention to develop such an internal combustion engine of the type mentioned that it has a reduced fuel consumption.

This object is achieved by an internal combustion engine having the features of patent claim 1. Advantageous embodiments with expedient and non-trivial developments of the invention are specified in the dependent claims.

An internal combustion engine according to the invention comprises at least one exhaust gas recirculation line, by means of which exhaust gas of the internal combustion engine is traceable from an exhaust gas side to an air side of the internal combustion engine. The internal combustion engine further comprises a turbocharger having an exhaust gas turbocharger, which comprises a turbine housing, in which a turbine wheel of the turbine is accommodated, and which has at least one of exhaust gas of the internal combustion engine through-flowable spiral channel, via which the exhaust gas is supplied to the turbine wheel. In this case, an adjustment of the turbine is provided, by means of which at least one nozzle cross-section of the spiral channel is adjustable. In the internal combustion engine according to the invention, the nozzle cross section of the spiral channel and a flow cross section of the return line are now jointly adjustable by means of the adjusting device. As a result, by means of the adjustment device, the throughflow cross section of the return line and thus a throughput of exhaust gas flowing through the return line can be adjusted parallel to the nozzle cross section and thus to a desired and necessary backlog of exhaust gas through the spiral channel and adapted to this backlog. This allows a positive influence on a charge cycle of the internal combustion engine due to the possibility of an exhaust backpressure upon expulsion of exhaust gas from a working space of the internal combustion engine as needed to adapt to a present operating point, which is associated with a very low fuel consumption and thus CO ₂ emissions of the internal combustion engine.

In an advantageous embodiment of the invention, the turbine housing has at least one further spiral channel, via which exhaust gas of the internal combustion engine for driving the turbine wheel can be fed to the turbine wheel. In this case, the first spiral channel, for example, as a partial spiral channel, in particular with a wrap angle in a range of 350 ° to 30 ° inclusive, formed while the other spiral channel as a full spiral channel, in particular with a wrap angle of more than 350 °, is formed. In this case, the full spiral channel functions, for example, as a so-called λ-spiral channel, by means of which the combustion air ratio of the internal combustion engine for displaying a desired torque and a desired power is adjustable. The partial spiral channel functions as a so-called EGR spiral channel (EGR exhaust gas recirculation), by means of which exhaust gas of the internal combustion engine can be traced from the exhaust side to the air side, where the exhaust gas is supplied to an air sucked by the internal combustion engine. By means of this exhaust gas recirculation, the emissions, in particular nitrogen oxide emissions, of the internal combustion engine can be lowered.

To represent mutually different amounts of exhaust gas to be recirculated and to display particularly large quantities of recirculating exhaust gas, the accumulation behavior of the EGR spiral channel can be adjusted as needed by means of the adjusting device. By narrowing the nozzle cross section, a particularly high amount of exhaust gas can be accumulated and returned in the spiral channel. If the nozzle cross-section is released by means of the adjusting device on the other hand, less exhaust gas is accumulated and returned compared to a nozzle cross-section narrowed for this purpose, with this accumulation behavior of the EGR spiral channel for reducing emissions the internal combustion engine is adaptable to different operating points of the internal combustion engine as needed.

The turbocharger of the exhaust-gas turbocharger is designed, for example, as a partial-flow turbine with two passages, wherein one of the passages is at least partially formed by the first spiral passage and the other is at least partially formed by the other spiral passage. If the first spiral channel is formed in the circumferential direction of the turbine wheel at least approximately over its entire circumference, the first spiral channel has a wrap angle of at least substantially 350 ° due to a tongue, and the further spiral channel is designed as a partial spiral channel, which extends in the circumferential direction of the turbine wheel over its circumference wraps around the turbine wheel in an angular range of substantially smaller than 350 °, the angular range in which the sub-spiral does not wrap around the turbine wheel is preferably used for the adjusting device, in particular a rotating mechanism which, as required, uses the sub-spiral channel or its nozzle cross-section by means of a locking body, In particular, a tongue, at least substantially free or contrast can narrow to adjust the Aufstauverhaltens this Teilspiralkanals. The design of the spiral channel of the turbine housing, which is used for accumulation and recirculation of exhaust gas, will thus be significantly larger, which means that an EGR throttling is minimal in reducing the wrap angle of the spiral channel.

By means of the adjusting device, the nozzle cross-section is variably adjustable, wherein the adjusting device is preferably continuously adjustable between mutually different positions, in particular pivot positions, and for example via a cover or a blading reduces the wrap angle and thus an effective area at the inlet of the turbine wheel, d. H. locked, or on the other hand releases.

Starting from a fully opened wrap angle, d. H. a completely released nozzle cross-section of the spiral channel, the nozzle cross-section of the spiral channel is reduced to increase the amount of pent-up exhaust gas with actuation of the adjusting device up to a minimum required or closed nozzle cross-section. Thus, it is possible to influence the Aufstauverhalten of the spiral channel and thus the turbine by means of the adjustment to higher EGR rates, but at the same time if necessary, an EGR rate, that is to reduce an amount of rückzuführendem exhaust, or such exhaust gas recirculation entirely to disable.

The fact that by means of the adjusting both the nozzle cross section and together with this the passage cross section of the return line is adjustable, the adjustment has a high functionality with a low number of parts, what the space requirements, the weight, the number of parts and thus the cost of the exhaust gas turbocharger in a low frame and provides the opportunity to adjust the flow area to the nozzle cross-section and thus the Aufstauverhalten and to seize further potential to reduce fuel consumption and CO ₂ emissions.

Further advantages, features and details of the invention will become apparent from the following description of a preferred embodiment and from the drawings. The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the description of the figures and / or in the figures alone can be used not only in the respectively specified combination but also in other combinations or in isolation, without the scope of To leave invention.

The drawings show in:

1 a schematic side view of a turbine housing for an exhaust gas turbocharger with a spiral channel designed as a full spiral channel and with a partial spiral channel formed as a spiral channel;

2 a schematic perspective view of the turbine housing according to 1 ;

3 a schematic sectional view of the full spiral passage of the turbine housing according to the preceding figures;

4 a schematic sectional view of the partial spiral passage of the turbine housing according to the preceding figures, wherein an adjusting device is provided, by means of which a nozzle cross section of the Teilspiralkanals is adjustable and which comprises a tongue which is set in a first rotational position;

5 a schematic sectional view of the partial spiral channel according to 4 wherein the tongue is set in a further rotational position;

6 a schematic sectional view of the sub-spiral channel according to the 4 and 5 wherein the tongue is set in a further rotational position;

7 a schematic sectional view of the partial spiral channel according to the 4 to 6 wherein the tongue is set in a further rotational position and wherein by means of the tongue of the nozzle cross-section of the partial spiral channel and a flow cross-section of a return line of an exhaust gas recirculation device for an internal combustion engine is adjustable; and

8th a schematic diagram of an internal combustion engine with an exhaust gas turbocharger with a turbine housing according to the preceding figures.

The 1 and 2 show a twin-bladed turbine housing 10 for a turbine 58 , ( 8th ) an exhaust gas turbocharger 56 for an internal combustion engine 25 , wherein an impingement of the turbine 58 over two floods 30 . 32 takes place, being one of the floods 30 . 32 at least partially by a full spiral channel 12 trained spiral channel and the other of the floods 30 . 32 at least partially by a partial spiral channel 14 formed spiral channel of the turbine housing 10 are formed.

The internal combustion engine 25 has, for example, a plurality of cylinders 28 on, the internal combustion engine 25 Exhaust gas from a first subset of cylinders 28 to one of the floods 30 . 32 and exhaust gas from another, different from the first subset, the second subset of the cylinder 28 to the other of the floods 30 . 32 promotes. Indicates the internal combustion engine 25 for example, four cylinders 28 on, for example, the exhaust gas from two of these cylinders 28 to the one flood 30 . 32 and thus to the full spiral channel 12 and the exhaust of the other two cylinders 28 to others of the floods 30 . 32 and thus, for example, to the sub-spiral channel 14 promoted.

In the turbine housing 10 is a turbine wheel 18 received, which the exhaust gas of the internal combustion engine 25 at least partially via the full spiral channel 12 as well as the sub-spiral channel 14 can be fed, causing the turbine wheel 18 can be driven by the exhaust gas. For this purpose, the exhaust gas first flows through respective flow cross sections A _{S of} the full spiral channel 12 or the sub-spiral channel 14 , whereupon it over respective nozzle cross-sections A _R in the region of a turbine wheel inlet of the turbine wheel 18 this flows and drives. As in particular the 3 and 4 can be seen, the full spiral channel 12 in the circumferential direction of the turbine wheel 18 over its circumference a wrap angle φ _S , which is for example at least 350 ° or greater. In contrast, the sub-spiral channel 14 a wrap angle φ _S , which in comparison to the wrap angle φ _{S of} the full spiral channel 12 is formed in a much smaller angular range.

This already indicates the sub-spiral channel 14 a much smaller nozzle cross section A _R than the full spiral channel 12 on. This results in a throughput parameter of the subspiral channel 14 flowing exhaust gas, which is less than a flow rate parameter of the full spiral channel 12 flowing exhaust gas of the internal combustion engine 25 , This is accompanied by a higher exhaust back pressure in the partial spiral channel 14 as in the full spiral channel 12 , whereby the sub-spiral channel 14 can accumulate a higher amount of exhaust gas than the full spiral channel 12 ,

Thus, the sub-spiral channel becomes 14 in the turbine designed as a twin-flow turbine 58 with the turbine housing 10 used to by means of a gas recirculation device via an exhaust gas recirculation line 16 Exhaust from an exhaust side 52 the internal combustion engine 25 on an airside 54 derselbigen return and of the internal combustion engine 25 sucked air to act on the recirculated exhaust gas. This allows emissions, in particular nitrogen oxide emissions, of the internal combustion engine 25 to reduce.

To represent different EGR rates (EGR exhaust gas recirculation), that is, to represent different amounts of recirculating exhaust gas, is an adjustment 20 with an associated with an adjusting locking body in the form of a tongue 22 provided, by means of which the nozzle cross section A _{R of} the partial spiral channel 14 is variably adjustable.

By rotational and / or translational movement of the adjusting ring is the tongue 22 around the axis of rotation 24 of the turbine wheel 18 rotatable between different rotational positions in which it completely releases the nozzle cross-section A _R ( 4 and 7 ), or the nozzle cross-section A _R at least partially closes ( 5 and 6 ). In particular the 1 it can be seen that in particular one of the subspiral channel 14 non-looped angular range in the circumferential direction of the turbine wheel 18 is used over the scope to provide or arrange the tongue 22 ,

In one in the 5 illustrated closed position of the tongue 22 , in which the nozzle cross section A _R completely by means of the tongue 22 is closed, the sub-spiral channel points 14 a very high Aufstauverhalten, with a very high amount of exhaust gas and on the return line 16 is traceable.

In contrast, the sub-spiral channel 14 in one in the 4 shown open position of the tongue 22 , in which the nozzle cross-section A _{R is} completely released, a very low Aufstauverhalten, with a very small amount of exhaust accumulated and only a very small amount or possibly no exhaust gas on the exhaust gas recirculation line 16 is returned.

The 8th shows the internal combustion engine 25 with a charging device 26 in which the turbocharger 56 with the turbine 58 with the turbine housing 10 is used according to the preceding figures. The internal combustion engine 25 has six cylinders 28 as working spaces, the exhaust gas from three cylinders 28 with a pressure p ₃₁ over the first tide 30 to the sub-spiral channel 14 is encouraged. The exhaust of the remaining cylinders 28 is at a pressure p ₃₂ across the second tide 32 to the full spiral channel 12 promoted. The turbine wheel 18 is from the full spiral channel 12 as well as the sub-spiral channel 14 flowing exhaust gas drivable and with a shaft schematically illustrated 34 a rotor of the exhaust gas turbocharger 56 connected, with which a compressor wheel 36 rotatably connected, causing the compressor wheel 36 is drivable. The compressor wheel 36 compressed by the internal combustion engine 25 according to a directional arrow 38 sucked air, whereby the air is heated. The air flows according to a directional arrow 40 Continue to a charge air cooler 42 which cools the air. Furthermore, the air flows according to a directional arrow 44 with a pressure p _2s in the cylinder 28 where it is fueled and burned, from which the exhaust gas is created, the floods 30 and 32 is supplied.

In the 8th is also the adjustment 20 with the tongue 22 shown schematically, by means of which the nozzle cross section A _{R of} the partial spiral channel 14 is variably adjustable. As in synopsis of 7 and 8th becomes clear, is by means of the tongue 22 not only the nozzle cross-section A _{R of} the partial spiral channel 14 variably adjustable. By tongue 22 is also a flow area A _EGR the exhaust gas recirculation line 16 adjustable, via which according to a directional arrow 46 at least part of the subspiral channel 14 flowing exhaust gas on the air side 54 the internal combustion engine 25 is traceable. For this purpose, the exhaust gas first flows through an exhaust gas recirculation cooler 48 with which the exhaust gas is cooled, before finally following a directional arrow 50 the compressed air is supplied.

About the tongue 22 Thus, the nozzle cross-section A _R and simultaneously the narrowest flow area A _EGR the exhaust gas recirculation line 16 certainly. In the case that the nozzle cross section A _R with the lowest Aufstauwirkung for the exhaust gas has the largest value, according to the flow cross-section A _EGR the exhaust gas recirculation line 16 be completely closed, if no amounts of recirculating exhaust gas in the corresponding operating ranges of the internal combustion engine 25 needed. In principle, however, diverse combinations of such coupled flow cross sections in the form of the nozzle cross section A _R and the flow cross section A _{AGR are} possible, which, for example via the adjusting ring with the tongue 22 can be adjusted in the form of a ring slide. Also the 7 shows the described double action of the tongue 22 which is in a rotational position in which the flow cross-section A _{AGR is} fully open.

The adjusting device 20 or the tongue 22 Thus, not only provides a way to adjust the nozzle cross section A _R , but also provides the functionality of an EGR valve, which makes it possible to adjust different EGR rates as needed.

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 102008039085 A1 [0002]

Claims (6)

Internal combustion engine ( 25 ) with at least one exhaust gas recirculation line ( 16 ), by means of which exhaust gas of the internal combustion engine ( 25 ) from an exhaust side ( 52 ) on an air side ( 54 ) of the internal combustion engine ( 25 ) is traceable, and with a turbine ( 58 ) having exhaust gas turbocharger ( 56 ), which a turbine housing ( 10 ), in which a turbine wheel ( 18 ) of the turbine ( 58 ), and which at least one of exhaust gas of the internal combustion engine ( 25 ) through-flowable spiral channel ( 12 . 14 ) over which the turbine wheel ( 18 ) the exhaust gas can be supplied, wherein an adjusting device ( 20 ) of the turbine ( 58 ) is provided, by means of which at least one nozzle cross-section (A _R ) of the spiral channel ( 12 . 14 ) is adjustable, characterized in that by means of the adjusting device ( 20 ) the nozzle cross-section (A _R ) of the spiral channel ( 12 . 14 ) and a flow area (A _AGR ) of the return line ( 16 ) are adjustable together. Internal combustion engine ( 25 ) according to claim 1, characterized in that the turbine housing ( 10 ) at least one further spiral channel ( 12 . 14 ) over which the turbine wheel ( 18 ) Exhaust gas of the internal combustion engine ( 25 ) can be fed. Internal combustion engine ( 25 ) according to one of claims 1 or 2, characterized in that the spiral channel ( 12 . 14 ) and / or optionally the further spiral channel ( 12 . 14 ) as a full spiral channel ( 12 ), in particular with a wrap angle (φ _S ) of greater than 350 degrees, and / or as a partial spiral channel ( 14 ), in particular with a wrapping angle (φ _S ) in a range of including 350 degrees to and including 30 degrees, is formed or are. Internal combustion engine ( 25 ) according to one of the preceding claims, characterized in that the adjusting device ( 20 ) at least one locking body ( 22 ), which is essentially rotationally movable and by means of which the nozzle cross section (A _R ) of the spiral channel (A _R ) 12 . 14 ) and the flow area (A _AGR ) of the return line ( 16 ) are adjustable together. Internal combustion engine ( 25 ) according to one of the preceding claims, characterized in that the adjusting device ( 20 ) between a nozzle cross-section (A _R ) of the spiral channel ( 12 . 14 ) and / or optionally the further spiral channel ( 12 . 14 ) substantially occluding closed position and the nozzle cross-section (A _R ) of the spiral channel ( 12 . 14 ) and / or optionally the further spiral channel ( 12 . 14 ) at least partially releasing open position is adjustable. Internal combustion engine ( 25 ) according to one of the preceding claims, characterized in that the adjusting device ( 20 ) between a flow cross-section (A _AGR ) of the return line ( 16 ) substantially closing the closed position and the flow cross-section (A _AGR ) of the return line ( 16 ) at least partially releasing open position is adjustable.

Images