WO2017102041A1

WO2017102041A1 - Valve element for a turbine of a turbocharger

Info

Publication number: WO2017102041A1
Application number: PCT/EP2016/001757
Authority: WO
Inventors: Viktor Buchmiller; Sunny Junge
Original assignee: Daimler Ag
Priority date: 2015-12-19
Filing date: 2016-10-24
Publication date: 2017-06-22
Also published as: DE102015016590A1

Abstract

The invention relates to a valve element (24) for a turbocharger turbine (10) through which exhaust gas can flow, comprising a valve element (26) by means of which a first exhaust gas quantity flowing through a bypass channel (22) of the turbine (10) and a second exhaust gas quantity flowing through an overflow opening (20) that differs from the bypass channel (22) for fluidically connecting two flows (14, 16) of the turbine (10) can be adjusted. The valve element (26) has two adjacently arranged hollow chambers (36) which are open towards the same side (34) and which are separated from each other by a valve element (26) partition (38) arranged between the hollow chambers (36).

Description

Valve element for a turbine of an exhaust gas turbocharger

The invention relates to a valve element for a turbine of an exhaust gas turbocharger.

From the general state of the art and in particular from the mass-produced vehicle, it is known internal combustion engines for driving cars with

Equip exhaust turbochargers to ensure efficient operation of their respective

To realize internal combustion engine. Such an exhaust gas turbocharger comprises a turbine through which exhaust gas can flow through the internal combustion engine and can be driven by the exhaust gas. Furthermore, the exhaust gas turbocharger comprises a compressor drivable by the turbine for compressing air. The compressed by means of the compressor air can be supplied to the internal combustion engine. Since the compressor of the turbine and the turbine of the exhaust gas of the internal combustion engine is drivable, energy contained in the exhaust gas can be used to compress the air.

Usually, such a turbine has a turbine housing and a in

Turbine housing rotatably received turbine wheel and a bypass passage through which at least a portion of the exhaust gas can bypass the turbine wheel. In other words, it is necessary to bypass the turbine wheel via the bypass channel of at least part of the exhaust gas. This means that the exhaust gas flowing through the bypass channel does not flow against the turbine wheel and consequently does not drive. The bypass channel is also referred to as wastegate or bypass and is used in particular to adjust the boost pressure of the exhaust gas turbocharger.

In addition, from the general state of the art multi-flow, especially double-flow, turbines are known. In this case, the turbine has at least two floods through which the exhaust gas can flow, by means of which the exhaust gas is guided to the turbine wheel. The floods are at least partially fluidly separated from each other. Object of the present invention is to provide a valve element by means of which a particularly advantageous operation of a turbine of an exhaust gas turbocharger can be realized.

This object is achieved by a valve element having the features of patent claim 1. Advantageous embodiments with expedient developments of the invention are specified in the remaining claims.

The valve element according to the invention for a flowing through exhaust bare and driven by the exhaust turbine of an exhaust gas turbocharger has a valve body by means of which a bypass passage of the turbine flowing first amount of the exhaust gas and a different from the bypass passage overflow for fluidly connecting two floods of the turbine second amount of the exhaust gas are adjustable. The turbine thus has, for example, at least two floods through which exhaust gas can flow, which are fluidically separated from one another, at least in respective partial regions or longitudinal regions. The turbine also has at least one overflow opening, via which the flows are fluidic

can be connected to each other, since the overflow is flowed through by exhaust gas. The valve body is then adapted to set a ready-made state of the turbine, the overflow opening flowing through a second amount of the exhaust gas.

Furthermore, the turbine in the fully manufactured state has a turbine wheel which can be driven by the exhaust gas and at least one bypass duct, by means of which the turbine wheel can be bypassed by at least part of the exhaust gas. This means that the exhaust gas flowing through the bypass channel does not flow against the turbine wheel and consequently does not drive, so that the exhaust gas flowing through the bypass channel flows around the turbine wheel.

The valve body is now also designed to adjust a through-flow of the first passage of the exhaust gas in the finished state of the turbine. In particular, it is conceivable that the overflow opening by means of

Valve body is fluidically blocked, so that no exhaust gas can flow through the overflow. Furthermore, it is conceivable that the bypass channel can be fluidly blocked by means of the valve body, so that no exhaust gas can flow through the bypass channel. If the valve body or the valve element releases the overflow opening, then exhaust gas can flow through the overflow opening, so that the floods are then fluidly connected to one another via the overflow opening. Is the overflow opening through The fluidically blocked the valve body, the floods are at least in the area of

Overflow fluidly separated from each other.

The valve body is thus used for the needs-based separation and connection of the floods. Furthermore, the same valve body is used to the bypass channel

to block and release as needed. The valve body thus has a dual function, since the valve body is used both for setting the first amount and for adjusting the second amount. Since the same valve body is used both for setting the first quantity and for adjusting the second quantity of the exhaust gas, no respective, separately formed valve parts for adjusting the respective amount are required, so that the number of parts, the weight and the cost and space requirements of Turbine can be kept low. Furthermore, by means of the exactly one valve body, it is possible to adjust the first quantity and the second quantity as needed and thus to adapt to different operating states, so that a particularly advantageous and, in particular, efficient operation of the turbine can be realized.

Furthermore, the valve body has two hollow chambers arranged next to one another and open towards the same side, which are separated from one another by a partition wall of the valve body arranged between the chambers. In the finished state of the turbine, for example, an actuator is provided, by means of which the valve element or the valve body is movable. By moving the valve body, the respective amounts of exhaust gas can be adjusted as needed.

It was found that by the design of the valve body with the

Hollow chambers and arranged between the hollow chambers partition the weight of the valve body and thus of the valve element can be kept particularly low overall, since the valve body can be produced with only a small material requirement. In this way, for example, by exhaust pulsations and / or vibrations caused loads that act on the actuator or on a kinematics for moving the valve member during operation of the turbine via the valve body, are kept low, so that the valve element and in particular the turbine as a whole their desired functions also can meet over a long service life. Furthermore, the valve body and thus the valve element can be made particularly cost-effective overall. In addition, an excessively massive design of the valve element can be avoided so that the material cracking susceptibility can be kept very low. In addition, it is possible to form the valve element or the valve body with an at least substantially uniform material wall thickness, so that the

Material susceptibility to tearing (TMF) can be kept particularly low.

In other words, it is possible the occurrence of thermomechanical

Stress caused cracks to keep low, so that a particularly high

Ensures functional performance of the valve element and thus the turbine as a whole.

Further advantages, features and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. 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 drawing shows in:

1 shows a detail of a schematic sectional view of a turbine for a

Exhaust gas turbocharger, comprising a valve element with a valve body, which two juxtaposed and open to the same side

Hollow chambers and a arranged between the hollow chambers and the hollow walls separated from each other separating wall has;

Fig. 2 is a schematic sectional view of the valve element;

Fig. 3 is a schematic perspective view of the valve element.

In the figures are the same or functionally identical elements with the same

Provided with reference numerals.

1 shows a detail of a schematic sectional view of a turbine as a whole designated 10 for an exhaust gas turbocharger of an internal combustion engine, in particular for driving a motor vehicle such as a passenger car. The exhaust gas turbocharger comprises the turbine 10 and a compressor, not shown in the figures, which in an intake of the

Internal combustion engine is arranged. During her operation, the sucks

Internal combustion engine air via the intake tract, wherein the air is directed by means of the intake tract in at least one combustion chamber, in particular in the form of a cylinder of the internal combustion engine. The cylinder is the air and fuel, in particular liquid fuel supplied, so that forms a fuel-air mixture in the cylinder. This fuel-air mixture is burned, whereby exhaust gas of the internal combustion engine is produced.

The internal combustion engine has an exhaust tract, by means of which the exhaust gas is discharged from the cylinder. As a result, the exhaust gas can flow through the exhaust gas, with the turbine 10 being arranged in the exhaust gas tract. Thus, the turbine 10 is also traversed by the exhaust gas of the internal combustion engine. The air flowing through the intake tract is compressed by means of the compressor, so that a particularly efficient operation of the internal combustion engine can be realized. In this case, the compressor can be driven by the turbine 10, wherein the turbine 10 can be driven by the exhaust gas of the internal combustion engine. As a result, energy contained in the exhaust gas can be used to compress the air.

The turbine 10 comprises a turbine housing 12, which can be seen in detail in FIG. 1, through which the exhaust gas can flow. The turbine housing 12 has two floods 14 and 16 through which exhaust gas can flow which are at least partially separated from one another fluidically and open into a receiving space of the turbine housing 12. In this case, the turbine housing 12 has a wall 18, which can be seen in detail from FIG. 1, through which the floods 14 and 16 are fluidically separated from one another, at least in a respective partial area. In the fully manufactured state of the turbine 10, a turbine wheel is received in the receiving space, which is rotatable about an axis of rotation relative to the turbine housing 12. The exhaust gas flowing through the flows 14 and 16 is guided by means of the floods 14 and 16 to the turbine wheel of the turbine 10, so that the exhaust gas flowing through the flows 14 and 16 can flow into the receiving space and flow to the turbine wheel. As a result, the turbine wheel is driven by the exhaust gas.

The turbine wheel is part of a rotor of the exhaust gas turbocharger, wherein the rotor also comprises a shaft and a compressor wheel of the compressor. It includes the Compressor a compressor housing in which the compressor is rotatably received. The compressor wheel is arranged coaxially with the turbine wheel and rotatable about the aforementioned axis of rotation relative to the compressor housing. The turbine wheel and the compressor wheel are non-rotatably connected to the shaft so that the compressor wheel can be driven by the turbine wheel via the shaft.

The turbine 10, in particular the turbine housing 12, furthermore has at least one overflow opening 20 adjoining the wall 8, for example in the flow direction of the exhaust gas, through the turbine housing 12, via which the flows 14 and 16 can be fluidly connected to one another. In addition, the turbine 10, in particular the turbine housing 12, a bypass passage 22 through which the turbine wheel is at least to bypass a part of the exhaust gas. This means that

Turbine housing 12, for example, has an inflow, via which the bypass passage 22, the exhaust gas from the flood 14 and / or 16 can be fed. The over the inlet opening - when it is released - in the bypass channel 22nd

inflowing exhaust gas can flow through the bypass channel 22 and thus the

Bypass turbine wheel, wherein the exhaust gas flowing through the bypass passage 22 does not flow against the turbine wheel and therefore does not drive. This bypassing the

Turbine is also referred to as blow-off or blow-off, as in the

By-pass channel 22 flowing exhaust gas contained energy is not used to drive the turbine wheel. The fluidic connection of the floods 14 and 16 via the overflow opening 20 is also referred to as a blow, Flutenumblasung or flood connection.

The turbine 10 further comprises a generally designated 24 valve element, which is movable relative to the turbine housing 12 and in particular pivotable about a pivot axis. The valve element 24 comprises a valve body 26 which is movable relative to the turbine housing 12, in particular about the pivot axis

swiveling, is. In the present case, the valve body 26 is integrally formed.

In particular, it is provided that the valve element 24 is formed as a whole in one piece. In addition, a coupled to the valve element 24

Lever element 28 is provided, via which the valve element 24, in particular the valve body 26, for example, is connected to an unrecognizable in the figures actuator. By means of the actuator, the valve element 24 and thus the valve body 26 via the lever member 28 relative to the turbine housing 12 are movable. The valve element 24, in particular the valve body 26, is movable between at least one closed position and at least one open position. By means of exactly one and presently integrally formed valve body 26 are both a bypass passage 22 flowing through the first amount of exhaust gas and the overflow opening 20 by flowing second amount of the exhaust gas adjustable. This means that the valve body 26 has a double function, since the exactly one valve body 26 is used both for setting the first quantity and for adjusting the second quantity of the exhaust gas. As a result, the number of parts, the weight and the cost of the turbine 10 can be kept particularly low, so that a particularly advantageous and in particular efficient operation of the turbine 10 can be realized.

The valve body 26 has a first sealing surface 30, which cooperates with the wall 18 in the closed position. As a result, the overflow opening 20 in the

Closed position by means of the valve body 26, in particular by means of the wall 18 and the sealing surface 30, fluidly blocked, so that the floods 14 and 16 are fluidly separated from each other in the region of the overflow opening 20. Furthermore, the valve body 26 has a second sealing surface 32, which in the closed position with the

Turbine housing 12, in particular with one of the wall 18 different wall of the turbine housing 12, cooperates. Thus, in the closed position, the bypass channel 22 or its inflow opening by means of the valve body 26, in particular by means of the sealing surface 32 and the further wall, fluidly blocked. In the open position, the valve body 26, for example, both the

Overflow 20 and the inflow opening or the

By-pass channel 22 free, so that exhaust gas through the overflow 20 and the

Inflow can flow. Thus, the floods 14 and 16 are fluidly connected to each other in the open position, and exhaust gas is blown off via the bypass passage 22.

In other words, for example, the bypass passage 22 is fluidly blocked in the closed position by means of the valve body 26, so that no exhaust gas can flow through the bypass passage 22. Alternatively or additionally, it is conceivable that in the

Closed position the overflow 20 is fluidly blocked by the valve body 26 so that no exhaust gas can flow through the overflow 20. Gives the

Valve body 26 the bypass ducts 22 and the overflow 20 freely, so exhaust gas through the bypass channel 22 and through the

Overflow opening 20 flow. The exactly one valve body 26 is thus for

need-based blocking and releasing the bypass channel 22 or used for appropriate locking and releasing the overflow 20 used. is the overflow opening 20 is blocked by means of the valve body 26, so the floods 14 and 16 are fluidly separated from each other at least in the region of the overflow opening 20, so that a flood separation is set.

On the other hand, if the valve body 26 releases the overflow opening 20, then the floods 14 and 16 are fluidically connected to one another, at least in the region of the overflow opening 20, so that a flood connection is set. By setting the flood separation, the turbine 10 can be operated, for example, in a shock charging operation. By adjusting the flood connection, the turbine 10, for example, in a

Jam charging operation can be operated as exhaust gas from one of the floods 14 and 16 in the other of the floods 14 and 16 can flow over or vice versa. By the need-based adjustment of the first quantity or by the

Appropriately enabling and locking the bypass channel 22 is it

For example, possible to set a boost pressure of the exhaust gas turbocharger by means of the valve body 26, so that a total of a particularly advantageous operation of the turbine 10 can be realized.

In order to realize a particularly advantageous and efficient operation of the turbine 10, the integrally formed valve body 26 has two hollow chambers 36 arranged next to one another and open towards the same side 34, which are separated from one another by a partition wall 38 of the valve body 26 arranged between the hollow chambers 36 , In particular, the hollow chambers 36 by means of

Partition 38 fluidly separated from each other. From Fig. 1 and 2 it can be seen that the sealing surface 30 of the valve body 26 is formed by the partition wall 38. On both sides of the partition wall 38 is at least one respective hollow chamber 36 partially delimiting wall 40 of the valve body 26 is arranged, wherein the partition wall 38 projects beyond the walls 40 to the side 34. As a result, the dividing wall 38, in particular the sealing surface 30, comes in the closed position of the valve body 26 in a defined support system with the wall 18, so that the overflow opening 20 is blocked in a defined manner.

3 shows the valve element 24 in a schematic perspective view. It can be seen particularly well from FIG. 3 that the dividing wall 38 projects beyond the walls 40 toward the side 34. Furthermore, it can be seen particularly clearly from FIG. 3 that the valve body 26 in the present case is in the form of a hollow sphere, in particular a hollow hemisphere or hollow sphere segment. Alternatively, however, other geometries of the valve body 26 are conceivable. For example, the valve body 26 as a cylinder, in particular as Hollow cylinder or hollow cylinder segment, cone or hollow cone or

Hollow cone segment, freeform, etc. be formed.

Fig. 2 shows the valve body 26 in a schematic sectional view. Particularly good from Fig. 2 it can be seen that the valve body 26 can be made with only a very small material requirement, so that the weight of the valve body 26 can be kept low. Furthermore, the valve body 26 can be produced in a particularly cost-effective manner. Furthermore, one is at least substantially uniform

Material wall thickness can be displayed, so that the material cracking susceptibility can be kept low. As a result of the low weight, furthermore, loads acting on the actuator mentioned during operation of the turbine 10 can be kept low, so that a particularly high functional reliability of the turbine 10 can be achieved even over a long service life.

LIST OF REFERENCE NUMBERS

10 turbine

12 turbine housing

14 flood

16 flood

18 wall

20 overflow opening

22 bypass channel

24 valve element

26 valve body

28 lever element

30 sealing surface

32 sealing surface

34 page

36 hollow chamber

38 partition

40 wall

Claims

claims

1. Valve element (24) for a flow-through of exhaust gas turbine (10) of a

Exhaust gas turbocharger, with a valve body (26), by means of which a

Bypass passage (22) of the turbine (10) flowing through the first amount of exhaust gas and one of the bypass passage (22) different overflow opening (20) for fluidly connecting two floods (14, 16) of the turbine (0)

The second valve body (26) has two hollow chambers (36) which are arranged next to each other and open towards the same side (34) and which are separated by a partition wall (38) of the valve body (26) between the hollow chambers (36) ) are separated from each other.

2. Valve element (24) according to claim 1,

characterized in that

the valve body (26) is integrally formed.

3. Valve element (24) according to claim 1 or 2,

characterized in that

on both sides of the partition (38) in each case at least one respective hollow chambers (36) partially delimiting wall (40) of the valve body (26) is arranged, wherein the partition wall (38) projects beyond the walls (40) to the side (34).

Turbine (10) for an exhaust gas turbocharger, comprising a valve element (24) according to the preceding claims.