WO2017153025A1

WO2017153025A1 - Valve element for a turbine of an exhaust gas turbocharger

Info

Publication number: WO2017153025A1
Application number: PCT/EP2017/000089
Authority: WO
Inventors: Viktor Buchmiller; Sunny Junge
Original assignee: Daimler Ag
Priority date: 2016-03-09
Filing date: 2017-01-26
Publication date: 2017-09-14
Also published as: DE102016002859A1

Abstract

The invention relates to a valve element (22) for a turbine (10) of an exhaust gas turbocharger, comprising a valve body (24), by which a quantity of an exhaust gas flowing through a bypass channel of the turbine (10) can be adjusted, wherein the valve body (24) comprises on a first side (30) at least a first hollow chamber (32) and on a second side (34) facing away from the first side (30) at least a second hollow chamber (36, 38).

Description

Valve element for a turbine of an exhaust gas turbocharger

The invention relates to a valve element, in particular a wastegate, for a turbine of an exhaust gas turbocharger according to the preamble of patent claim 1.

Such valve elements, in particular in the form of so-called waste gates, for turbines of exhaust gas turbochargers are already well known from the general state of the art and in particular from the production of standard vehicles. Such a valve element has a valve body, by means of which an amount of a bypass channel of the turbine flowing through the exhaust gas is adjustable. As a result, for example, to be provided by the exhaust gas turbocharger boost pressure is adjustable.

When finished, the turbine has a turbine housing with a receiving space in which a turbine wheel is rotatably received about an axis of rotation relative to the turbine housing. The turbocharger is included

For example, part of an internal combustion engine, in particular a motor vehicle, wherein the turbine, in particular the turbine wheel, can be driven by the exhaust gas of the internal combustion engine. For this purpose, the exhaust gas by means of

Turbine housing led to the receiving space and thus to the turbine wheel, so that the exhaust gas can flow to the turbine wheel and thereby drive.

Usually, the turbine has at least one bypass channel over which the turbine wheel of at least a portion of the exhaust gas to bypass. The bypassing of the turbine wheel is also referred to as blow-off or blow-off, since the exhaust gas flowing through the bypass channel bypasses the turbine wheel and thus does not flow against it and does not drive.

The valve element is commonly referred to as wastegate or wastegate valve and is relative to the turbine housing between a closed position and at least one open position movable. In the closed position of the bypass channel by means of the valve element, in particular by means of the valve body, for example, fluidly blocked, so that no exhaust gas can flow through the bypass channel. In the open position, the valve element releases the bypass channel, so that at least part of the exhaust gas can flow through the bypass channel and thus bypass the turbine wheel.

Object of the present invention is to develop a valve element of the type mentioned in such a way that the weight of the valve element can be kept very low.

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.

To a valve element, in particular a wastegate, in the preamble of

Claim 1 specified type such that the weight of the valve element can be kept particularly low, it is inventively provided that the valve body on a first side at least a first

Hollow chamber and on one of the first side facing away from the second side has at least one second hollow chamber. The invention is based in particular on the recognition that the valve body of a conventional valve element is usually solid, that is to say as a solid body or wastegate body, and in particular in the form of a plate. This leads to a high weight of the

Valve body and thus the valve element as a whole, so that, for example, high accelerations and in particular high forces act on the valve element, in particular when the valve element or the valve body is moved. In particular, the high weight leads to vibrations and

Exhaust pulsations caused loads, which also on a kinematics for

Move the valve body to be transferred. Furthermore, a conventional

Valve body on a large accumulation of material due to which it is due to

thermomechanical loads can cause cracks.

These problems can now be avoided by means of the valve element according to the invention, since the valve body has on the sides facing away from each other at least one hollow chamber. At the same time, by means of the valve body of the

Valve element according to the invention ensures a sufficient sealing function be so that the bypass channel by means of the valve body, for example, can be fluidly locked safely. Since the valve body in contrast to a solid body can be produced with a particularly low cost of materials, the

Valve body are made particularly inexpensive. Furthermore, it is possible to realize an at least almost uniform wall thickness and thus material, so that the material cracking susceptibility and thus the risk that there are cracks in the

Valve body comes, can be kept very low. Furthermore, excessive vibrations and thus excessive loads on a kinematics for moving the valve element can be avoided, so that a particularly robust operation of the turbine and thus of the exhaust gas turbocharger as a whole can be realized.

The respective hollow chambers are cavities which are open, for example, in each case on exactly one side and thus open into the surroundings of the valve body via the respective exactly one side. Thus, the respective hollow chamber, for example, a

Recess which is open on exactly one side and has a recess bounding the recess in a first direction and at least one wall of the valve body delimiting the recess in all other directions extending perpendicular to the first direction.

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 of a

Exhaust gas turbocharger, comprising a valve element for adjusting an amount of exhaust gas flowing through a bypass passage of the turbine, wherein Fig. 1 is used to explain the background of the invention;

Fig. 2 is a schematic perspective view of an inventive

Valve member; FIG. 3 shows a schematic side view of the valve element according to FIG. 2; FIG. and

Fig. 4 is a further schematic perspective view of the valve element according to

FIGS. 2 and 3.

In the figures, the same or functionally identical elements are provided with the same reference numerals.

Fig. 1 shows a detail in a schematic sectional view of a generally designated 10 turbine 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, resulting in exhaust gas of the internal combustion engine.

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. The compressor can be driven by the turbine 10, which in turn can be driven by the exhaust gas, so that 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 comprises a wall 18, which can be seen in detail in FIG. 1, through which the floods 14 and 16 at least in one Partial region or length range are fluidly separated from each other. In fully manufactured condition of the turbine 10 is in the receiving space a

Recorded turbine wheel, which is rotatable about an axis of rotation relative to the turbine housing 12. The exhaust gas flowing through the floods 14 and 16 is guided by means of the floods 1 and 16 to the turbine wheel of the turbine 10, so that the exhaust gas flowing through the floods 14 and 16 can flow into the receiving space and the turbine wheel can flow. 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. In this case, the compressor comprises a compressor housing in which the compressor wheel is rotatably received. The compressor wheel is about the aforementioned axis of rotation relative to the

Rotatable 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 18, for example in the flow direction of the exhaust gas, through the turbine housing 12, via which the flows 14 and 16 can be fluidically connected to one another. In addition, the turbine housing 12 has a bypass channel, not visible in the figures, through which the turbine wheel can be bypassed, at least by a part of the exhaust gas. This means that

Turbine housing 12, for example, has an inflow opening, via which the exhaust passage from the flood 14 and / or 16 can be fed. The exhaust gas flowing into the bypass channel via the inlet opening-when it is released-can flow through the bypass channel and thus bypass the turbine wheel, whereby the exhaust gas flowing through the bypass channel does not flow against the turbine wheel and consequently does not drive. This bypassing of the turbine wheel is also called

Blowing or blow-off referred to as in the the bypass channel

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

The turbine 10 further includes a generally designated 22 valve member which is movable relative to the turbine housing 12 and in particular pivotable about a pivot axis. The valve member 22 includes a valve body 24 which is relatively to the turbine housing 12 movable, in particular about the pivot axis

swiveling, is.

In the embodiment illustrated in Fig. 1, the valve body 24 is solid, that is formed as a solid body. The valve body 24 is connected to a presently formed as a pin connecting element 28, via which the valve body 24 and the valve element 22 is connected or coupled in total with a kinematics. By means of this kinematics, the valve element 22 is movable relative to the turbine housing 12. The kinematics include a present as

Lever element 26 formed actuating element, by means of which the valve element 22 and thus the valve body 24 are movable, in particular pivotable, are.

The valve element 22, in particular the valve body 24, is between a

Closed position and at least one open position relative to the turbine housing 12 movable, in particular pivotable about the pivot axis. By means of exactly one and example, integrally formed valve body 24 are a the

Passage through first amount of the exhaust gas and a

Overflow opening 20 flowing through second amount of the exhaust gas adjustable. This means that the valve body 24 has a double function, since the exactly one valve body 24 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.

In the closed position of the valve body 24 or of the valve element 22, the bypass channel or the inflow opening of the bypass channel is fluidly blocked by means of the valve body 24, so that no exhaust gas can flow through the bypass channel or can flow into the bypass channel. Further, it is provided that in the closed position of the valve body 24 and the valve element 22 and the overflow 20 is fluidly blocked by means of the valve body 24 so that the floods 14 and 16 in the closed position of the valve body 24 and the valve member 22 is not fluidically via the overflow 20 connected to each other. In other words, the floods 14 and 16 in the

Closed position of the valve body 24 by means of this fluidly separated from each other. In the open position, the valve body 24 gives both the bypass channel

or the inflow opening and the overflow opening 20 free, whereby exhaust gas can flow both through the overflow opening 20 and into or through the bypass channel. In the open position, the floods 14 and 16 are thus fluidly connected to each other via the overflow opening 20, so that in the

Open position of the valve body 24 is set a flood connection. In the

Closed position of the valve body 24, however, a flood separation is set. Since the overflow opening 20 is arranged upstream of the turbine wheel by the turbine housing 12 relative to the flow direction of the exhaust gas, the turbine 10 can be operated in the closed position of the valve body 24 in a shock charging operation. In the open position of the valve body 24, the turbine 10 in a

Jam charging operation are operated as exhaust gas from the flood 14 in the flood 16th

can overflow or vice versa.

2 to 4 show an embodiment of the valve element 22, wherein the weight of the valve element 22 can be kept particularly low. From a synopsis of Fig. 2 to 4 is particularly well seen that - to keep the weight of the valve element 22 is particularly low - the valve body 24 on a first side 30 at least a first hollow chamber 32 and on one of the first side 30 opposite or from the first side 30 facing away from, second side 34 has two second hollow chambers 36 and 38. The respective hollow chambers 32, 36 and 38 are formed as respective recesses, wherein the respective recess is open on exactly one respective side and thereby open into the environment of the valve body 24. In other words, the respective hollow chamber 32, 36 or 38 has a passage opening 40, via which the respective hollow chamber 32, 36

or 38 opens into the environment of the valve body 24. The respective

Through opening 40 is free and therefore not blocked.

The connecting element 28 is arranged on the first side 30 and thus on the side of the hollow chamber 32, wherein the valve body 24 integral with the

Connecting element 28 is formed. The respective hollow chamber 32, 36

or 38 has a bottom 42 formed by the valve body 24, through which the respective hollow chamber 32, 36 and 38 in a first

Direction is limited. Furthermore, the respective hollow chamber 32, 36 or 38 has an integrally formed with the bottom 42 wall 44 of the valve body 24, wherein the respective hollow chamber 32, 36 and 38 in all perpendicular to the first direction extending directions through the wall 44 is limited. Since the respective Hollow chamber 32, 36 and 38 has the respective passage opening 40, the respective hollow chamber 32, 36 and 38 in a first direction opposite and parallel to the first direction extending second direction open and thus opens in the second direction in the vicinity of the valve body 24th ,

The respective second hollow chambers 36 and 38, in particular their respective bottoms 42, are set back relative to respective surface regions 46 of the valve body 24 adjoining the respective second hollow chambers 36 and 38, so that the respective second hollow chambers 36 and 38 are opposite to the respective ones Form respective recesses of the valve body 24 form respective hollow chambers 36 and 38 subsequent surface regions 46. In this case, the valve body 24 on the second side 34 has a web 48 which protrudes from the surface regions 46 and thus projects beyond the surface regions 46. In this case, the second hollow chambers 36 and 38 are arranged by the web between the hollow chambers 36 and 38

separated from each other.

By the described, from Fig. 2 to 4 recognizable embodiment of the valve body 24, a particularly high strength of the web 48 due to a particularly advantageous connection to the valve body 24 can be realized. Furthermore, excess material can be avoided at a tip S of the valve body 24, but provided as a tongue or trained web 48 is provided for separating the floods 14 and 16. The respective hollow chamber 32, 36 and 38 can as

Ball segment be formed. For example, the hollow chamber 32 is formed as a half-hollow sphere or half-hollow sphere segment. Of course, any other geometries such as cylinders, cones, freeform, etc. are possible.

Daimler AG

LIST OF REFERENCE NUMBERS

turbine

turbine housing

flood

wall

overflow

valve element

valve body

lever member

Connecting element first page

first hollow chamber second side

second hollow chamber second hollow chamber

Through opening

ground

wall

surface area

web

top

Claims

Daimler AG claims

1. Valve element (22) for a turbine (10) of an exhaust gas turbocharger, with a

Valve body (24), by means of which an amount of a bypass passage of the turbine (10) flowing through the exhaust gas is adjustable,

characterized in that

the valve body (24) has at least one first hollow chamber (32) on a first side (30) and at least one second hollow chamber (36, 38) on a second side (34) remote from the first side (30).

2. Valve element (22) according to claim 1,

characterized in that

at least one of the hollow chambers (32, 36, 38) via at least one

Through opening (40) opens into the environment of the valve body (24).

3. Valve element (22) according to claim 1 or 2,

characterized in that

the first side (30) with the valve body (24) is a connecting element (28) is connected, by means of which the valve element (22) with a

Actuating element (26) for moving the valve element (22) is connectable.

4. Valve element (22) according to claim 3,

characterized in that

the hollow chamber (36, 38) arranged on the second side (34) adjoins at least one surface region (46) of the valve body (24) adjoining the hollow chamber (36, 38) arranged on the second side (34) Forming recess, wherein the valve body (24) on the second side (34) has at least one web (48) which projects from the surface region (46).