WO2009012989A1

WO2009012989A1 - Flow housing of a turbo charger

Info

Publication number: WO2009012989A1
Application number: PCT/EP2008/006052
Authority: WO
Inventors: Ralf Böning; Hartmut Claus; Dirk Frankenstein; Holger Fäth; Jochen Held; Marc Hiller; Stefan Krauss; Stefan Nowack
Original assignee: Continental Automotive Gmbh
Priority date: 2007-07-23
Filing date: 2008-07-23
Publication date: 2009-01-29
Also published as: DE102007034235A1

Abstract

The invention relates to a flow housing for a turbo charger, comprising: at least one first and a second flow channel, wherein the two flow channels loop around a rotor of the turbo charger at a predetermined looping angle each, and having a mutual blowing unit operated via an actuator.

Description

description

Flow housing of a turbocharger

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

Turbochargers usually have an exhaust gas turbine and a compressor. The exhaust gas turbine is in this case arranged in an exhaust gas flow and connected to the compressor via a turbo shaft in the intake. In this case, a turbine wheel and a compressor wheel are rotatably mounted on the shaft. The housing of the turbocharger in this case has a corresponding turbine and compressor housing, and a bearing housing for the shaft. In operation, the exhaust gas flow passing through the turbine housing drives the turbine wheel, with the turbine wheel in turn driving the compressor wheel. This increases the pressure in the intake tract of the engine so that a larger amount of air enters the cylinder during the intake stroke.

This causes an increase in the power output of the engine, as more oxygen is available and a correspondingly larger amount of fuel can be burned.

From the prior art, for example, twin flow casings with two turbine inlet ducts are known as flow casings for the turbine wheel. The turbine flow channels in the form of two floods lead to a common turbine wheel, which is arranged on a shaft. The shaft is in turn arranged with one in an air supply duct

Compressor wheel connected. The twin flow housing is provided with a so-called. Wastegate for both floods. However, such twin flow housings have the disadvantage of inferior exhaust pulse conversion. Furthermore, a highly complex bypass channel design is necessary. In addition, there is an extreme thermal stress load on the partition wall between the two floods. Furthermore, from the prior art, as disclosed in DE 10 2004 039 477, a single-flow flow housing is known. In this case, a turbine housing is provided for an exhaust gas turbocharger, which has a one-piece spiral housing made of sheet metal, which surrounds a distributor with guide vanes. However, such a single-flow flow housing has disadvantages in terms of thermodynamics and responsiveness.

Accordingly, it is the object of the present invention to provide an improved flow housing for a turbocharger, which has a simpler construction and in which the Abgaspulsationsausnutzung is improved.

This object is achieved by a flow housing for a turbocharger having the features of patent claim 1.

Accordingly, according to the invention a flow housing for a turbocharger is provided, comprising: - at least a first and a second flow channel, wherein the two flow channels wrap around a rotor of the turbocharger at a predetermined wrap angle and have a common blow-off device, which is actuated via an actuator.

The flow housing has the advantage that the Abgaspulsationsausnutzung can be improved. Thus, a steeper torque increase of the engine can be made possible, with simultaneous control possibility of turbine performance with a single actuator via a central 'Abgasabblas- device.

Advantageous embodiments and further developments of the invention will become apparent from the dependent claims and the description with reference to the drawings.

According to one embodiment of the invention, the actuator, for example, a wastegate on. The boost pressure In this case, the regulation flap has the advantage that the two flow channels can be actuated very simply, ie, for example, opened or closed.

According to a further embodiment of the invention, the flow channels loop around a turbine wheel with a wrap angle of up to 180 °. The flow channels in this case have, for example, the same wrap angle, with the wrap angle of all flow channels totaling, for example, 360 °. In addition to at least two flow channels also three, four and more flow channels are provided. For example, with three flow channels, the respective wrap angle is 120 ° and, for example, 90 ° for four flow channels. Several flow channels have the advantage that, due to the smaller pipe cross-section, a pulsating impingement of the turbine is maintained.

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

In a further embodiment according to the invention, 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 explained in more detail with reference to the exemplary embodiments indicated in the schematic figures of the drawings. Show it:

Fig. 1 is a schematic side view of a turbine housing according to the prior art; Fig. 2 is a schematic side view of a turbine housing according to the invention;

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

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

Fig. 5 is a schematic side view of the turbine housing and a Abblaseorgans of the turbine housing of FIG. 3; and

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

In all figures, identical or functionally identical elements and devices have been provided with the same reference numerals, unless stated otherwise.

1, a schematic view of a prior art turbine flowcase 10 is shown. The turbine wheel 14 of the turbine is here indicated by dashed lines in a greatly simplified manner. The flow guidance to the turbine is fully symmetrical in this flow housing 10. This means that two separate, opposite inlet flanges 12 are provided on the flow housing 10. 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 occasionally in the commercial vehicle sector and unregulated, i. without blurring, application.

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

The Doppelabgasström with the channel guide, which consists of the two floods 18, in this case has a common inlet flange 12, for introducing the exhaust gas directly to the turbine wheel. Such a common inlet flange 12 and the common channel guide have the advantage that a common Abgasabblaseinrichtung 22 can be realized without much constructive effort, in contrast to the previously described flow housing 10 of FIG. 1, in which the Abgasabblaseinrichtungen and the ducting formed separately are.

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

As already mentioned above, a common Abgasabblaseinrichtung 22 can be provided in the invention. At the same time, a control possibility of the turbine power with only one actuator 24 is given via this central exhaust gas blow-off device 22. This has the advantage that the provision of the control option is particularly simple and inexpensive, since only one actuator 24, such as preferably a wastegate 26, is necessary. However, the invention is not limited to a wastegate 26. It is for the It will be apparent to one of ordinary skill in the art that the regulatory capability can be embodied in various ways. In principle, however, it is also conceivable to provide more than one actuator 24.

The combination of a much more robust, compared to the twin flow housing, multiple pulsation turbine housing with a control option of turbine performance by a single actuator 24 via a central Abgasabblaseinrichtung 22, improved Abgaspulsationsaus- utilization can be achieved. As a result of the smaller tube cross-sections of the two floods 18 and a merging of the exhaust pipes only shortly before the turbine inlet, the advantages of the pulsating loading of the turbine 14 are maintained. In this case, a mutual cancellation of the pressure pulsations of the exhaust gas of the two floods 18 can be substantially prevented ,

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 is 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 is guided separately in the two floods 18 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 are fed via the common inlet flange 12 just before the turbine 14 to the turbine wheel. 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 flood, 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 can be switched very easily via the common blow-off device 22 and the actuator 24. More specifically, depending on the operating conditions, both floods 18 can be opened or closed, for example, in order to switch on or off corresponding cylinders.

The arrangement of the floods 18 of the flow housing 10 with a wrapping angle α of 180 ° is shown in Fig. 3 from the viewing direction of the bearing housing side. The turbine wheel 14 of the turbine is here also indicated in a greatly simplified manner with dashed lines. Here, the common inlet flange 12 of the floods 18 is shown. As already mentioned above, more than two floods 18 can 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 preferably each have the same wrap angle α and form in the sum, for example, an angle of 360 °. The decisive factor here is that the exhaust gas streams are brought together, if possible, just before the turbine and the turbine 14 directly fed.

4 shows again a perspective view of the flow housing 10 according to the invention. The entire core structure with the separate flow guidance to the turbine 14 and to the common blow-off device 22 is shown, consisting of the two flows 18. Furthermore, the two bypass passages 28 are the floods 18, through which the exhaust gas can be discharged. In Fig. 5, the flow housing 10 according to the invention from the side of the common blower 22 is shown. As previously mentioned, a wastegate 26 is used as the common blow-off device 22, for example. The wastegate 26 has inter alia a pivotable flap plate 30, and a socket 32 in which an actuating device is arranged for actuating the flap plate 30 and thus for closing or opening of the bypass channels 18th

The wastegate 26 has the advantage that it can be easily arranged laterally on the flow housing and installed without requiring a substantial additional building space. In addition, the placement of the floods 18 on one side or with an inlet flange 12 allows the wastegate to easily actuate both bypass lines, unlike the prior art where, with the twin flow housing, the floods are from two opposite ones Sides are led to the turbine wheel and therefore require two inlet flanges 12. Furthermore, the two floods 18 which divide the exhaust gas flow are shown in FIG.

By the common blower 22 and thus the control 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.

As previously described, a twin-flow turbine typically has two separate 360 ° spirals arranged axially one behind the other. Such twin-flow turbines are thermodynamically and thermomechanically worse as the twin-flow turbine according to the invention, for example, having two separate 180 ° spirals.

Due to the axial arrangement, in the case of the twin-flow turbine, before the wheel entry, an area arises 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 one

However, wheel load is again the reason why this variant is currently used in passenger car series, which must rely on the existing wheel geometries.

In Fig. 6, the flow housing 10 according to the invention is shown in a further view. In this case, the common inlet flange 12 of the two floods 18 is shown, as well as the separate channel guidance to the turbine wheel through the floods 18. In addition, the separate blow-off channels or bypass channels 28 are shown.

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

Claims

claims

1. flow housing (10) for a turbocharger, comprising: at least a first and a second flow channel (18), wherein the two flow channels (18) loop around an impeller of the turbocharger, each with a predetermined Umwingungswin- kel (α) and a common Abblaseinrichtung ( 22) which is actuated via an actuator (24).

2. Flow housing according to claim 1, characterized in that the actuator (24) has, for example, a wastegate valve (26).

3. flow housing according to at least one of claims 1 or 2, d a d u c h e c e n e c e s in that the flow channels (18) wrap around the impeller with a wrap angle (α) of up to 180 °.

4. The flow housing according to claim 1, wherein the flow channels each have the same wrap angle .alpha.

5. flow housing according to at least one of claims 1 to 4, d a d u r c h e c e n e c e s in that the wrapping angle (α) of the flow channels (18) form an angle of 360 °.

6. flow housing according to at least one of claims 1 to 5, characterized that, for example, three or four flow channels (18) are provided, the three flow channels (18) wrap around the impeller with a wrapping angle (α) of, for example, 120 ° and the four flow channels (18) the impeller with a wrap angle (α) of, for example, 90th Wrap around.

7. The flow housing according to claim 1, wherein the flow housing is a turbine flow housing and the impeller is a turbine wheel.

8. The flow housing according to claim 1, wherein the flow channels have a common inlet flange.

9. The flow housing according to claim 1, wherein each flow channel has a bypass channel.

10. Turbocharger with a flow housing (10) for a turbine according to one of claims 1 to 9.

11. The vehicle with a turbocharger according to claim 10, wherein the vehicle is, for example, a commercial vehicle or a motor vehicle such as a passenger car.