WO2011101005A1

WO2011101005A1 - Turbine for an exhaust gas turbocharger

Info

Publication number: WO2011101005A1
Application number: PCT/EP2010/007296
Authority: WO
Inventors: Thomas Kuhn; Nils Brinkert
Original assignee: Daimler Ag
Priority date: 2010-02-18
Filing date: 2010-12-01
Publication date: 2011-08-25
Also published as: DE102010008411B4; DE102010008411A1

Abstract

The invention relates to a turbine (10) for an exhaust gas turbocharger, comprising a turbine housing (12), in which a turbine wheel that can be exposed to a waste gas of an internal combustion engine is accommodated and which has at least two channels (14, 16), which are fluidically separated from each other at least in some sections and through which the exhaust gas can flow, and at least one valve (22), which can be moved between a closed position that closes at least one bypass channel (20) and at least one open position that releases the bypass channel at least in some sections and by means of which the turbine wheel can be bypassed at least by part of the exhaust gas, wherein the at least two channels (14, 16) are fluidically separated from each other by the valve (22) at least in some sections in a separating section (24) in at least one position of the valve (22), wherein the valve (22) has at least one intermediate position, in which the bypass channel (20) is closed and the at least two channels (14, 16) are fluidically connected to each other in the separating section (24).

Description

Turbine for an exhaust gas turbocharger

The invention relates to a turbine for an exhaust gas turbocharger specified in the preamble of claim 1. Art.

DE 10 2004 055 571 A1 discloses an exhaust gas turbocharger for a

Internal combustion engine with a compressor in an intake tract and a turbine in an exhaust system with a turbine wheel and with a first and a second flood. Upstream of the floods a flow distribution device is arranged with a bypass, which a rotary valve with a rotation axis and a

Having rotary valve housing. By means of the rotary valve, a connection between the bypass and the floods can be produced. The rotary valve has two

Flow channels on.

This known exhaust gas turbocharger has further potential to improve the efficiency of the internal combustion engine in an efficient manner.

It is therefore an object of the present invention to provide a turbine for an exhaust gas turbocharger, which improves the efficiency of an associated

Internal combustion engine in an efficient manner allows.

This object is achieved by a turbine for an exhaust gas turbocharger having the features of patent claim 1. Advantageous embodiments with expedient and non-trivial developments of the invention are specified in the dependent claims.

A turbine according to the invention for an exhaust gas turbocharger comprises

Turbine housing, in which an acted upon by an exhaust gas of an internal combustion engine turbine wheel is received and which at least two at least partially fluidly separated from each other and can be flowed through by the exhaust gas Has floods. Furthermore, the turbine comprises at least one closed position closing off at least one bypass duct and at least one valve which can open the bypass duct at least in regions and via which the turbine wheel is at least part of the turbine

To bypass the exhaust gas. In at least one position of the valve, the at least two flows are fluidically separated from one another in a separation area by the valve, wherein the valve has at least one intermediate position in which the flow channel is closed and the at least two floods are fluidically connected to one another in the separation area.

The turbine according to the invention thus enables, on the one hand, a so-called surge charging of the internal combustion engine assigned to the turbine. In this case, the exhaust gas of the internal combustion engine from a subset of a total amount

Working spaces, in particular cylinders, the internal combustion engine to flow through one of the floods of the turbine, while the exhaust gas can flow from a different amount of the first subset of the total amount of work spaces, in particular cylinders, the internal combustion engine through the other of the floods of the turbine. This is a reduction of exhaust-carrying volumes between the working spaces of the internal combustion engine and the turbine or the

Turbocharger realized for each of the floods, resulting in the effect of said

Bump charging leads.

On the other hand, the turbine according to the invention allows at least a reduction of the effect of the surge charging and the representation of a charge accumulation, in which the flows of the turbine or the turbine housing upstream of the turbine, at least in the intermediate position of the valve fluidly connected or connectable.

Are the at least two floods in the closed position of the valve fluidly separated from each other at least in the separation area, so when adjusting the valve, which is also referred to as wastegate, from the closed position into the

Intermediate position initially created a fluidic connection between the at least two floods. The flow channel is still closed.

This leads similar to a so-called exhaust of the exhaust gas in the

Open position of the valve, in which the bypass channel is at least partially released, to a reduction in the performance of the turbine, but without sacrificing to have to accept the efficiency of the turbine or a mass reduction, as in the blow-off, so at least partially releasing the

Flow channel, which is the case. Namely, if the bypass channel is opened, whereby at least part of the exhaust gas can bypass the turbine wheel, without impinging on it, thus driving it, then enthalpy is unnecessarily degraded, which does not change the charge and thus the efficiency of the

Combustion engine can benefit. This disadvantage is at least significantly reduced by the turbine according to the invention, which leads to efficient operation of the internal combustion engine. This is accompanied by a reduction in the fuel consumption of the internal combustion engine, resulting in low C0 ₂ emissions.

Furthermore, additional degrees of freedom in the design of the turbine wheel are created by the turbine according to the invention, what the low consumption of

Internal combustion engine and thus low C0 _2- emissions benefit another. In addition, this allows an improved response of the turbine and thus the entire exhaust gas turbocharger, thus providing a better

Torque characteristic of the internal combustion engine is associated. In addition, the turbine according to the invention has a low complexity, whereby the advantages mentioned are achieved efficiently, inexpensively and with high reliability.

Subsequent to the fluidic connection of the at least two floods of the turbine or of the turbine housing, with further adjustment of the valve and, if necessary, further regulation and thus adjustment of the turbine and thus of the exhaust gas turbocharger to a present operating point of the internal combustion engine, a flow cross section of the bypass duct with the valve releasable, whereby the exhaust gas in the executed way the turbine wheel can handle without this.

The valve has, for example, the shape of an axial slide, in which the valve is at least substantially translationally movable in the axial direction. Also possible is a rotary valve in which the valve is at least substantially rotationally movable to first fluidly connect the at least two floods together and free to give in the connection and, if necessary, the flow channel.

Other forms of actuation, for example by means of a driver, are also possible. The at least two floods of the turbine housing or the turbine may be symmetrical to each other or asymmetrical to each other, in any embodiment, the said advantages of the efficiency improvement and thus the fuel consumption reduction and better response associated.

Further advantages, features and details of the invention will become apparent from the following description of several preferred embodiments and from the drawings. The features mentioned above in the description and

Feature combinations as well as the features and feature combinations mentioned below in the description of the figures and / or shown alone in the figures are not only in the respectively indicated combination but also in others

Combinations or alone, without departing from the scope of the invention.

The drawings show in:

Fig. 1 in fragmentary form a schematic longitudinal sectional view of a

Turbine according to the invention for an exhaust gas turbocharger;

2 shows a detail of a schematic longitudinal sectional view of another

Embodiment of the turbine according to the invention;

Fig. 3 in part a perspective longitudinal sectional view of another

Embodiment of the turbine according to the invention; and

4 shows a detail of a longitudinal sectional view of a further embodiment of the turbine according to the invention.

FIG. 1 shows a turbine 10 for an exhaust-gas turbocharger with a turbine housing 12 which has a first flow 14 and a second flow 16. The floods 14 and 16 are of an exhaust gas of a corresponding to the exhaust gas turbocharger

Internal combustion engine can be flowed through and at least partially fluidly separated from each other by a wall 18 of the turbine housing 12. Furthermore, the turbine 10 has a flow channel 20 through which at least a subset of the total exhaust gas can flow. The exhaust gas flowing through the bypass duct 20 is conveyed through the bypass duct 20 to a turbine wheel, not shown in FIG. 1 and received in the turbine housing 12 bypassed, whereby the exhaust gas can handle the turbine wheel without it and handle it.

The flow channel 20 can be closed by a valve 22 of the turbine 10 which can be adjusted between a closed position and at least one open position, or can be opened at least in regions.

As can be seen from FIG. 1, the two flows 14 and 16 are fluidically separated from one another in a separation region 24 by the valve 22. In the position of the valve 22 shown in FIG. 1, the flow channel 20 is closed by the valve 22 and the flows 14 and 16 are fluidly separated from each other. For this purpose, the valve 22 comprises a valve disk 30 which is fixedly connected to a shaft 32 translationally displaceable in the direction of a directional arrow 26, whereby the valve disk 30 can also be moved in accordance with the directional arrow 26. The valve also includes a valve cover 35, wherein the valve stem 32 and the valve disk 30 are slidable relative to the valve cover 35.

If the valve stem 32 and thus the valve plate 30 spent in the direction of a direction arrow 27 by a stroke, while the valve cover 35 of the valve 22 by Federkraftbeaufschlagung by a on the valve cover 35 and on the other hand on a flow channel 20 forming wall 34 supported spring element 28 to how before remaining on a valve cover 36 corresponding to the valve seat 36, the valve 22 assumes an intermediate position, in which the

Bypass passage 20 is further closed by the valve cover 35 of the valve 22, the two floods 14 and 16, however, are fluidically interconnected in the separation region 24.

Is by the turbine in the position of the valve 22 shown in FIG. 1 a

Shock charge shown, which results from a reduction in volume of exhaust-carrying volumes between cylinders of the internal combustion engine and the turbine 10, so is characterized by the executed intermediate position of the valve 22, in which therefore the floods 14 and 16 are fluidly connected to each other, a congestion charge.

By the fluidic connection of the floods 14 and 16, the power of the turbine 10 is reducible, and similar to how the exhaust gas would bypass the bypass duct 20 without applying the turbine wheel this. This bypassing the Exhaust gas, which is also referred to as blowing, is at the turbine 10 for

Power reduction, however, not necessarily needed, which goes hand in hand with avoiding unwanted degradation of enthalpy. Conversely, this means an improvement in the efficiency of the internal combustion engine, which is associated with low fuel consumption and thus with low C0 ₂ emissions derselbigen. If, if necessary, a part of the exhaust gas to apply the turbine without this, so drive, bypass, the valve 22 can be further adjusted in the direction of the directional arrow 27 on the stroke hi out, whereby the valve plate 30 entrains the valve cover 35 and the valve cover 35 lifts off from its valve seat 36 against the Federkraftbeaufschlagung and the valve 22 the

Circulation passage 20 releases. This represents the functionality of a so-called

Wastegate is to further reduce the performance of the turbine 10.

The turbine 10 thus enables a very high efficiency of

Internal combustion engine and in a very efficient manner, so with only a small space requirement, low operating costs and low costs.

FIG. 2 shows a further embodiment of the turbine 10, wherein the same applies to the turbine 10 according to FIG. 1 as for the turbine according to FIG. 2. The difference between the turbine 10 according to FIG. 2 and the turbine 10 according to FIG. 1 consists in the fact that the valve 22 comprises a first valve disk 30 ', which in at least one position of the valve 22 fluidly separates the floods 14 and 16 at least in regions , The valve disk 30 'is fixedly connected to the valve stem 32. The valve 22 according to FIG. 2 comprises a second valve disk 30 ", wherein the valve disk 30 'and the valve stem 32 in turn are displaceable relative to the valve disk 30". If the valve stem 32, which is movable in the direction according to the directional arrow 26, is moved in the direction of the directional arrow 27, the valve disk 30 'is also moved in the direction of the directional arrow 27. The valve disk 30 "is not moved thereby and closes the flow channel 20.

If the valve disk 30 'has covered the stroke hi, then the floods 14 and 16 are fluidically connected to one another in the separation region 24, whereby the already described transition from the impact charge to the accumulation charge is created. If the valve 22 is moved further in the direction of the directional arrow 27, then the valve disk 30 'takes with it the second valve disk 30 "of the valve 22, and the valve disk 30" hitherto closing the bypass channel 20 releases the bypass channel 20. For this purpose, the valve 22 is now to operate against the spring force of the spring element 28, which is supported on the one hand on the wall 34 and on the other hand on the valve plate 30 ". If the actuation of the valve 22 of the turbine 10 according to FIG. 2 is perpendicular or transverse to the course of the flows 14 and 16, and the valve 22 comprises two valve disks 30 'and 30 ", FIG. 3 shows a further embodiment of the turbine 10 the valve 22, which comprises the valve stem 32 and only one valve disc 30 "'. The valve 22 of the turbine 10 according to FIG. 3 is to be referred to as axial slide, which has a translational, linear movement for adjusting the valve 22. In a first position designated A, the floods 14 and 16 are fluidically separated from each other by the valve 22 and the flow channel 20 is closed.

In the intermediate position of the valve 22 designated B, the flows 14 and 16 are fluidically connected to one another in the separation region 24, while the flow-through channel 20 is still closed. In a position designated by C of the valve 22, the floods 14 and 16 are fluidically connected to each other and the flow channel 20 is released, whereby the exhaust gas of the internal combustion engine this

To flow through the flow channel and thus can handle the turbine to act on this. The turbine 10 according to FIG. 3 has a particularly simple, cost-effective and functionally reliable design, with simultaneous realization of all the advantages already mentioned. Incidentally, for the turbine according to FIG. 3, the same applies to the turbine 10 according to FIGS. 1 and 2.

4 shows a further embodiment of the turbine 10, in which the valve 22 again comprises only the single valve disk 30 ''. In contrast to the valve 22 according to FIG. 3, the valve disk 30 '' is now not translational but by means of a rotary valve or pivoting mechanism can be actuated at least essentially rotationally via a lever arm 38 which is firmly connected on one side to the valve disk 30 "and on the other hand can be pivoted about a pivot axis 40. The position A, B and C of the valve 22 shown in FIG 3. The turbine 10 according to FIG. 4 also has a simple and thus cost-effective and functionally reliable design with the simultaneous realization of the aforementioned advantages.

Claims

claims

Turbine (10) for an exhaust gas turbocharger with a turbine housing (12) in which a can be acted upon by an exhaust gas of an internal combustion engine turbine wheel is received and which at least two at least

partially fluidically separated from each other and from the exhaust gas flowable through flooding (14, 16), and with at least one between at least one Umströmungskanal (20) closing the closed position and at least one Umströmungskanal at least partially releasing open position adjustable valve (22) via which the turbine wheel to get around at least part of the exhaust gas,

characterized in that

the at least two floods (14, 16) are at least partially fluidically separated from one another in at least one position of the valve (22) in a separation area (24) by the valve (22), the valve (22) having at least one intermediate position in which the flow channel (20) closed and the at least two floods (14, 16) in the separation region (24) are fluidly interconnected.

Turbine (10) according to claim 1,

characterized in that

the valve (22) has a valve disk (30, 30 ', 30 ", 30"') and a valve cover (35).

3. turbine (10) according to claim 2,

characterized in that

the at least two floods (14, 16) in the closed position of the valve (22) are fluidically separated from one another by the valve disk (30, 30 ', 30 ", 30'") and the

Bypass passage (20) of the valve cover (35) is closed.

4. turbine (10) according to any one of claims 2 or 3,

characterized in that

the at least two flows (14, 16) are fluidically connected to one another in the intermediate position of the valve (22) and the flow channel (20) is closed by the valve cover (35).

5. turbine (10) according to any one of claims 2 to 4,

characterized in that

the at least two floods (14, 16) are fluidically connected to one another in the open position of the valve (22) and the flow channel (20) is at least partially released.

6. turbine (10) according to any one of the preceding claims,

characterized in that

the valve (22) between the open position, the intermediate position and / or the closed position is at least substantially pivotable.

7. turbine (10) according to any one of the preceding claims,

characterized in that

the valve (22) between the open position, the intermediate position and / or the closed position is at least substantially translationally adjustable.

8. turbine (10) according to claim 7,

characterized in that

the valve (22) is at least substantially translationally adjustable in the axial direction of the valve (22).