DE102007034235A1 - Flow housing of a turbocharger - Google Patents

Abstract

The invention relates to a flow housing for a turbocharger, comprising: at least a first and a second flow channel, wherein the two flow channels loop around an impeller of the turbocharger, each with a predetermined wrap and have a common blower, which is actuated via an actuator.

Description

The The invention relates to a flow housing of a Turbocharger in which a turbine wheel is arranged on a turbo shaft is.

turbocharger usually have an exhaust gas turbine and a compressor. The exhaust gas turbine is in this case arranged in an exhaust gas flow and with connected to the compressor via a turbo shaft in the intake. In this case, a turbine wheel and a compressor wheel are rotatable on the shaft stored. The housing of the turbocharger has this case corresponding turbine and compressor housing, and a bearing housing up for the wave. In operation, the exhaust gas flow, the is passed through the turbine housing, the turbine wheel on, wherein the turbine wheel in turn drives the compressor wheel. Thereby so the pressure in the intake tract of the engine increases, so while the intake stroke a larger amount of air in the Cylinder passes. This causes an increase in power output of the engine, as more oxygen is available and burned a correspondingly larger amount of fuel can be.

Out The prior art are as a flow housing for example, twin turbine housing for the turbine wheel with two turbine inflow channels known. The Turbine flow channels in the form of two floods lead to a common turbine wheel, which on one Wave is arranged. The wave is in turn with one in one Air supply channel arranged compressor wheel connected. The twin flow housing is provided with a so-called wastegate for both floods. Such However, twin-flow housings have the disadvantage of being inferior Exhaust gas pulse conversion. Furthermore, a highly complex bypass channel design necessary. In addition, it comes to an extreme thermal stress load the partition between the two floods.

Furthermore, from the prior art, as in the DE 10 2004 039 477 discloses a single-flow flow housing known. In this case, a turbine housing is provided for an exhaust-gas turbocharger, which has a single-flow spiral housing made of sheet metal, which surrounds a distributor with guide vanes. However, such a single-flow flow casing has disadvantages in terms of thermodynamics and responsiveness.

Therefore It is the object of the present invention, an improved Flow housing for a turbocharger to provide, which has a simpler structure and in which the Abgaspulsationsausnutzung is improved.

These Task is through a flow housing for a turbocharger having the features of claim 1.

• – wenigstens einem ersten und einem zweiten Strömungskanal,
• – wobei die beiden Strömungskanäle ein Laufrad des Turboladers mit jeweils einem vorbestimmten Umschlingungswinkel umschlingen und
• – eine gemeinsame Abblaseeinrichtung aufweisen, die über einen Aktuator betätigt wird.

Accordingly, according to the invention there is provided a flow housing for a turbocharger, comprising:

• At least a first and a second flow channel,
• - Wherein the two flow channels wrap around an impeller of the turbocharger, each with a predetermined angle of wrap and
• - Have a common Abblaseeinrichtung which is actuated via an actuator.

The Flow housing has the advantage that the Abgaspulsationsausnutzung can be improved. This can be a steeper torque increase of the engine are made possible with simultaneous control of the turbine power with a single actuator via a central Abgasabblaseinrichtung.

advantageous Refinements and developments of the invention will become apparent the dependent claims and the description with reference on the drawings.

According to one Embodiment of the invention, the actuator, for example, a Wastegate on. The charge pressure control flap has the Advantage that the two flow channels very simple pressed, d. H. for example, opened or closed can be.

According to one another embodiment of the invention The flow channels wrap around a turbine wheel with a wrap angle of up to 180 °. The flow channels have, for example, the same wrap angle, wherein the wrap angle of all flow channels in total, for example, 360 °. Next at least two flow channels can also provided three, four and more flow channels are. With three flow channels is the respective wrap angle, for example, 120 ° and at four flow channels, for example, 90 °. Several Flow channels have the advantage of being through the smaller pipe cross section of a pulsating impingement the turbine is maintained.

In another embodiment of the invention the flow channels have a common inlet flange on. This has the advantage that the flow channels very simply merged just before the turbine entrance can be and in this case the exhaust gas fed directly to the turbine wheel can be. This also has an advantageous effect on a pulsating Supplying the turbine.

In a further inventive Aus Guidance form at least one, several or all flow channels are provided with a bypass channel. These bypass channels are connected via at least one actuator, for example a wastegate.

The Invention will be described below with reference to the schematic figures the drawings specified embodiments closer explained. Show it:

1 a schematic side view of a turbine housing according to the prior art;

2 a schematic side view of a turbine housing according to the invention;

3 a schematic side view of the turbine housing according to 2 from the bearing housing side;

4 a schematic perspective view of the turbine housing according to 3 ;

5 a schematic side view of the turbine housing and a Abblaseorgans of the turbine housing according to 3 ; and

6 a schematic front view of the turbine housing and an inlet flange of the turbine housing according to 3 ,

In all figures are the same or functionally identical elements and devices - if nothing else is indicated - with the same reference numerals been provided.

In 1 is a schematic view of a turbine flow housing 10 shown in the prior art. The turbine wheel 14 the turbine is here indicated in a simplified manner with dashed lines. The flow guide to the turbine is in this flow housing 10 fully symmetrical. This means that there are two separate, opposite inlet flanges 12 on the flow housing 10 are provided. This has the consequence that a complex management of the exhaust manifold is necessary. A common blow-off device for controlling the exhaust gas flow is practically impossible to realize. For this reason, this embodiment finds only isolated in the commercial vehicle sector and unregulated, ie without blow-off, application.

Furthermore, in 2 an embodiment of a flow housing 10 for a turbine of a turbocharger (not shown) according to the invention. Here is the casting core schematically 16 the flow-leading parts shown. In this case, the flow housing 10 for example, two floods 18 on, which divide the exhaust gas stream into two exhaust gas streams. The floods 18 In this case, at least one turbine wheel (not shown) wraps around at a wrap angle α of, for example, 180 °.

The double exhaust stream with the ducting leading from the two floods 18 exists, in this case has a common inlet flange 12 on, for introducing the exhaust gas directly to the turbine wheel. Such a common inlet flange 12 and the common ducting have the advantage of having a common Abgasabblaseinrichtung 22 can be realized without great design effort, in contrast to the flow housing described above 10 according to 1 in which the Abgasabblaseinrichtungen and the channel guide are formed separately.

According to the invention, a serial division of the exhaust gas mass flow into two, three, four or more exhaust gas mass flows takes place, the associated floods 18 a turbine wheel (not shown) in each case wrap around with a wrap angle α of, for example, up to a maximum of 180 °. In contrast to the invention, however, wrap around in the multiple current housing 10 according to the prior art, as in 1 shown is the floods 18 the turbine wheel (not shown) to each 360 °.

As already mentioned above, in the invention, a common Abgasabblaseinrichtung 22 be provided. About this central Abgasabblaseinrichtung 22 is at the same time a control option of the turbine power with only one actuator 24 given. This has the advantage that the provision of the control option is particularly simple and inexpensive, since only one actuator 24 as preferably a wastegate 26 , necessary is. However, the invention is not on a wastegate 26 limited. It will be apparent to one of ordinary skill in the art that the control possibility may be embodied in various ways. In principle, however, it is also conceivable to have more than one actuator 24 provided.

By combining a, compared to the twin current housing much more robust, multi-pulsation turbine housing with a possibility of regulating the turbine performance by a single actuator 24 via a central Abgasabblaseinrichtung 22 , improved exhaust pulsation utilization can be achieved. Due to the smaller tube cross sections of the two floods 18 and a merger of the exhaust pipes until just before the turbine entrance remain the advantages of the pulsating impingement of the turbine 14 receive. In this case, a mutual cancellation of the pressure pulsations of the exhaust gas of the two floods 18 in the Be prevented substantially.

Here, for example, in a 4-cylinder engine consisting of the cylinders 1 to 4, two cylinders 1 and 3 (not shown) interconnected via the turbocharger, the cylinder 1, for example, in the exhaust stroke generates a pressure wave, while the cylinder 3 in a compression phase (UT) and generates a suction wave. According to the invention, each of the two cylinders 1 and 3 is one of the floods 18 assigned. This results in that the exhaust gas from the cylinders 1 and 3 separated in the two floods 18 is guided and thereby the pressure wave of the cylinder 1 and the suction shaft of the cylinder 3 can not cancel each other in part. Instead, the exhaust gases through the common inlet flange 12 just before the turbine 14 fed to the turbine. In this way, the pressure pulsation of the exhaust gas can be used efficiently. In particular, a turbine efficiency of theoretically 170% based on a laminar combustion chamber measurement can thus be achieved at low rotational speeds, for example in a range from 1200 to 1400 rpm.

In the prior art, however, in a single-flow turbine housing 10 the exhaust gases from the cylinders, here the cylinders 1 and 3, received by a common Flute, which has the effect described above, that the pressure wave of the cylinder 1 and the suction shaft of the cylinder 3 influence each other negatively or partially cancel. This in turn leads to a reduction of the turbine efficiency.

Another significant advantage of the invention is that the individual floods 18 very easy on the common blower 22 and the actuator 24 can be switched. More specifically, depending on the operating conditions, both floods 18 For example, be opened or closed to turn on corresponding cylinder or not.

The arrangement of the floods 18 of the flow housing 10 with a wrap angle α of 180 ° is in 3 as seen from the perspective of the bearing housing side. The turbine wheel 14 The turbine is here also greatly simplified indicated by dashed lines. Here is also the common inlet flange 12 the floods 18 shown. As mentioned before, you can also get more than two floods 18 be provided, for example, four floods, which then wrap around a turbine wheel with a wrap angle α of, for example, 90 °. The floods 18 In this case, they preferably each have the same wrap angle α and in the sum form, for example, an angle of 360 °. Decisive here is that the exhaust gas streams brought together, if possible, just before the turbine and the turbine wheel 14 be forwarded directly.

4 again shows a perspective view of the flow housing according to the invention 10 , Here, the entire core structure with the separate flow guidance to the turbine 14 and to the common blow-off device 22 shown, consisting of the two floods 18 , Furthermore, the two bypass lines 28 the floods 18 shown, through which the exhaust gas can be removed.

In 5 is the flow housing according to the invention 10 from the side of the common blower 22 shown. As a common blow-off device 22 Here, as already mentioned above, for example, a wastegate 26 used. The wastegate 26 has, among other things, a hinged flap plate 30 on, as well as a jack 32 in which an actuating device is arranged for actuating the flap plate 30 and thus to close or open the bypass channels 18 ,

The wastegate 26 has the advantage that it can be easily arranged and installed laterally on the flow housing, without requiring a substantial additional space. In addition, the arrangement of the floods leaves 18 on one side or with an inlet flange 12 it is that the wastegate can very easily operate both bypass lines, in contrast to the prior art, where in the twin flow housing, the floods are guided from two opposite sides to the turbine wheel and therefore two inlet flanges 12 need. Furthermore, in 5 the two floods 18 shown, which divide the exhaust stream.

By the common blower 22 and thus the regulation of a single actuator 24 we use in a car only possible. Only in this way is it possible to meet the basic conditions demanded in terms of cost, package and control strategy without having to forego the advantages with regard to thermodynamics and the response that a twin-flow turbine offers unequivocally compared to single-flow and even twin-flow turbines.

A Twin flow turbine, as previously described, normally two separate 360 ° spirals arranged axially one behind the other are arranged. Such twin flow turbines are thermodynamic and thermo-mechanically, however, worse than the twin-flow turbine according to the invention, for example, two separate 180 ° spirals.

The axial arrangement creates an area in the twin-flow turbine before the wheel entry in which both floods come together. In this case, the pressure pulsation in the exhaust gas, which is actually useful, can partially cancel each other out. This reduces the thermodynamic efficiency of the twin-flow turbine and, to the same extent, reduces the load on the turbine wheel. The lower wheel load, in turn, is the reason why this variant is currently used in passenger car series, which must rely on the existing wheel geometries.

In 6 is the flow housing according to the invention 10 shown in another view. Here is the common inlet flange 12 the two floods 18 shown, as well as the separate ducting to the turbine wheel through the floods 18 , In addition, the separate Abblaskanäle or bypass channels 28 shown.

Even though the present invention with reference to preferred embodiments described herein, it is not limited thereto but modifiable in many ways.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 102004039477 [0004]

Claims (11)

Flow housing ( 10 ) for a turbocharger, comprising: - at least a first and a second flow channel ( 18 ), - whereby the two flow channels ( 18 ) wrap around an impeller of the turbocharger, each with a predetermined wrap angle (α), and - a common blow-off device ( 22 ), which via an actuator ( 24 ) is pressed. Flow housing according to claim 1, characterized in that the actuator ( 24 ), for example, a wastegate ( 26 ) having. Flow housing according to at least one of claims 1 or 2, characterized in that the flow channels ( 18 ) wrap the impeller at a wrap angle (α) of up to 180 °. Flow housing according to at least one of claims 1 to 3, characterized in that the flow channels ( 18 ) each have a same wrap angle (α). Flow housing according to at least one of claims 1 to 4, characterized in that the wrap angle (α) of the flow channels ( 18 ) form an angle of 360 ° overall. Flow housing according to at least one of claims 1 to 5, characterized in that, for example, three or four flow channels ( 18 ) are provided, wherein the three flow channels ( 18 ) wrap the impeller at a wrapping angle (α) of, for example, 120 ° and the four flow channels ( 18 ) wrap around the impeller with a wrap angle (α) of, for example, 90 °. Flow housing according to at least one of claims 1 to 6, characterized in that the flow housing ( 10 ) is a turbine flow housing and the impeller is a turbine wheel. Flow housing according to at least one of claims 1 to 7, characterized in that the flow channels ( 18 ) a common inlet flange ( 12 ) exhibit. Flow housing according to at least one of claims 1 to 8, characterized in that each flow channel ( 18 ) a bypass channel ( 28 ) having. Turbocharger with a flow housing ( 10 ) for a turbine according to one of claims 1 to 9. Vehicle with a turbocharger according to claim 10, wherein the vehicle is, for example, a commercial vehicle or motor vehicle, such as a car, is.