Such coupling rods are used for connecting an actuator, in particular an electric actuator which is mounted for example on a compressor housing of a compressor of an exhaust-gas turbocharger, to an outside lever of a so-called VTG cartridge. As a result of an actuation of the actuator, the coupling rod is moved axially and the outside lever is pivoted, which in turn rotates an adjusting ring of the VTG cartridge, and thus the vanes of the VTG cartridge are moved between an open position and a closed position.

It is an object of the present invention to provide a coupling rod of the type in the preamble of claim 1 which is of simple and thus inexpensive design and which permits axial length compensation.

This object is achieved by the features of claim 1.

By virtue of the fact that the coupling rod has two sleeve-like end pieces which can be pushed onto a rod-like intermediate piece, it is possible in a simple manner for the effective length of the coupling rod to be adjusted and for the set final assembly position on the intermediate piece to be fixed, preferably by means of a welded connection.

The dependent claims contain advantageous developments of the invention.

In addition to a simple technical construction which can be assembled easily and in a reliable manner, there is the resulting advantage that identical parts can be used for exhaust-gas turbochargers with flap end pieces and control capsule end pieces.

Further details, advantages and features of the present invention become apparent from the following description of exemplary embodiments with reference to the drawing, in which:

Figure 1 shows a perspective illustration of a first embodiment of a coupling rod according to the invention,

Figures 2 and 3 show a first installation situation of the coupling rod as per figure 1 on an exhaust-gas turbocharger embodiment,

Figure 4 shows a second installation situation of the coupling rod according to the invention as per figure 1 in a further exhaust-gas turbocharger embodiment, figure 5 shows the installation situation of the coupling rod as per figure 1 in an exhaust-gas turbocharger with a flap-type VTG,

figure 6 shows a second embodiment of the coupling rod according to the invention with cranked intermediate piece in the installed state in a further embodiment of an exhaust-gas turbocharger according to the invention, and

figures 7 and 8 show the installation situation of the coupling rod as per figure 1 in an exhaust-gas turbocharger in which the actuator (electric actuator) is installed with a direction of action which differs from the direction of action of the outside lever of the VTG.

Figure 1 illustrates a first embodiment of a coupling rod 1 which comprises a first end piece 2 and a second end piece 3. The end pieces 2 and 3 are pushed onto the intermediate piece 4, which is formed as a connecting rod.

As figure 1 also shows, the first end piece 2 has a sleeve 5 and the second end piece 3 has a sleeve 6, said sleeves being pushed onto the connecting rod 4 and fixed on the connecting rod 4 in the final assembly position illustrated in figure 1.

To realize the fixing, it is preferable for a welded connection to be provided, for this purpose, in the embodiment illustrated in figure 1, the sleeves 5 and 6 have in each case one welding window 7 and 8 respectively, into which the weld material can be introduced.

The sleeves 5 and 6 are assembled in each case from two sheet-metal halves 9,

10 (in the case of sleeve 5) or sheet-metal halves 11, 12 (in the case of sleeve 6).

As figure 1 also shows, the sleeves 5 and 6 have in each case one compensating ball joint 13 and 14 respectively. Here, the compensating ball joints 13 and 14 are arranged in in each case one receiving recess 15 and 16 respectively in an associated holding plate 17 (in the case of sleeve 5) or 18 (in the case of sleeve 6).

Here, the holding plate 17 is inserted into an associated insertion slot 19 of the sleeve 5 and the holding plate 18 is inserted into an associated insertion slot 20 of the sleeve 6, and said holding plates are fixed in said insertion slots 19 and 20 respectively, for example by means of a welded connection.

As figure 1 shows, the insertion slots 19 and 20 merge into the respectively associated welding windows 7 and 8.

In the embodiment of figure 1 , the connecting rod 4 is of straight form. Figures 2 and 3 illustrate a first embodiment of an exhaust-gas turbocharger 21 according to the invention which has a turbine 22 and a compressor 23. Between the turbine 22 and the compressor 23 there is arranged a bearing housing 24.

To the compressor 23 there is fastened an actuator 25 which has an actuator lever 26 which is connected to one of the two compensating ball joints of the coupling rod 1 as per figure 1.

Also shown is an outside lever 27 of a VTG cartridge which is not illustrated in detail in figure 3. A VTG cartridge is understood to mean a structural unit which, between a vane bearing ring and a disk, delimits an inflow duct for the passage of exhaust gases to the turbine wheel. A VTG cartridge of said type also has a multiplicity of vanes which are arranged in the inflow region. The vanes can be moved rotatably in the vane bearing ring between a closed and an open position. For this purpose, the vanes have vane shafts each having an axis of rotation. The vane shafts in turn are connected to vane levers each having a lever head which engages into an associated groove of an adjusting ring. The adjusting ring of a VTG cartridge of said type is connected to the coupling rod 1 via a lever mechanism, wherein the outside lever 27 of the lever mechanism is visible in figure 3. Owing to the construction, explained above and illustrated in figure 1, of the coupling rod 1 according to the invention, it is possible for the effective length of the coupling rod to be varied by varying the weld position of the end pieces 2 and 3.

Through the use of the compensating ball joints 13 and 14 described on the basis of figure 1, it is possible to accept a small axial offset without there being any influence on the hysteresis of the overall system as per figures 3 and 4. The mounting of the coupling rod 1 in the case of different alignments of the actuator 25 and of the VTG outside lever 27 is therefore made considerably easier.

Figure 4 shows a further embodiment of an exhaust-gas turbocharger 21 according to the invention, wherein all of the components explained above with reference to figures 2 and 3 are denoted by the same reference numerals.

In this embodiment, too, the coupling rod 1 connects the actuator lever 26 to a VTG outside lever 28, which in this case is of cranked form. In this embodiment of the exhaust-gas turbocharger 21, the coupling rod 1 permits mounting in the case of identical alignment of the actuator and of the VTG outside lever. Figure 5 illustrates a so-called flap-type exhaust-gas turbocharger 21 which can likewise be equipped with the coupling rod 1 according to the invention. The construction of the coupling rod 1 which has been explained on the basis of figure 1 makes fitting in difficult installation situations in exhaust-gas turbochargers of said type significantly easier.

Figure 6 shows a further embodiment of an exhaust-gas turbocharger 21 according to the invention, in which use is however made of a coupling rod Γ, the connecting rod 4' of which is of cranked form, as can be seen from figure 6. Said cranked configuration of the connecting rod 4' permits a further variant for adaptation to different turbocharger designs. The construction of the coupling rod Γ otherwise corresponds to that of the coupling rod 1 of figure 1.

Figures 7 and 8 show different views of an exhaust-gas turbocharger 1 in which the actuator 25 is installed with a direction of action which differs from the direction of action of the VTG outside lever 28. It is possible in the case of such a turbocharger design, too, for use to be made of the coupling rod 1 as per figure 1 with its compensating ball joints 13 and 14.

In addition to the above written disclosure of the invention, reference is explicitly made to the illustration in figures 7 to 8 to supplement the disclosure of the invention.

LIST OF REFERENCE SIGNS

1, 1 ' Coupling rod

2 First end piece

3 Second end piece

4, 4' Intermediate piece/connecting

5, 6 Sleeves

7, 8 Welding windows

9, 10, 11, 12 Sheet-metal halves

13, 14 Spherical joints

15, 16 Receiving recess

17, 18 Holding plate

19, 20 Insertion slot

21 Exhaust-gas turbocharger

22 Turbine

23 Compressor

24 Bearing housing

25 Actuator

26 Actuator lever

27 VTG outside lever

28 Cranked VTG outside lever