Patent Application
20150377119
This application claims the benefit of German Patent Application No. 102014212581.2 filed Jun. 30, 2014, the disclosure of which is herein incorporated by reference in its entirety.
1. Field of the Invention
The invention relates to a control arrangement of an exhaust-gas turbocharger.
2. Description of the Related Art
So-called “downsized engines” with high power-to-weight ratios have an increased tendency to vibrate, such that the components of an exhaust-gas turbocharger combined with such engines are subject to intense loading owing to vibrational friction wear. This wear also affects the components of control arrangements of such turbochargers, for example for the actuation of a wastegate flap. Here, even special materials for the stated components, with a wide variety of surface treatments, can reach their limits.
It is therefore an object of the present invention to provide a control arrangement of the type indicated in the preamble of claim 1, by means of which it is possible for vibrational friction wear of its components to be at least considerably minimized.
In detail, said object is achieved by way of the control arrangement of an exhaust-gas turbocharger which has a regulating unit, for example in the form of a hydraulic control capsule, which is equipped with a regulating rod. The regulating rod has a free end region which is connected to a guide piece which is fastened for example to an outer lever which can be connected by way of a control shaft to a wastegate flap. According to the invention, the free end region of the regulating rod is connected to the guide piece by way of a spring clip. In this case, the spring clip engages around the free end region and is clamped to the guide piece.
Firstly, a simplified articulated and preloaded connection of the regulating rod to the guide piece is advantageously realized in this way. By means of the spring preload, it is possible for rattling noises in the natural frequency range to be prevented.
The dependent claims contain advantageous developments of the invention.
If the spring clip is equipped with two mutually spaced-apart spring rings which are connected to one another by means of a connecting bracket, this yields the advantage of a unipartite form of the spring clip, such that a resilient, articulated connection of the regulating rod to the guide piece can be realized using only a single installation means. This yields the advantage that said construction is logistically simple, as a smaller number of individual parts is required.
Furthermore, the advantage is attained that simple production of the spring clip in a punching and bending process is possible, with the external contour and the form of the spring rings being predefined at the same time.
If the spacing of the spring rings is equal to the material thickness of the free end region, this yields the advantage of engaged-around, clearance-free installation of the end region of the regulating rod.
If the spacing between the spring rings is variable owing to the design of the connecting bracket, this yields the advantage of the possibility of adaptation to tolerance deviations in the material thickness of the free end region.
If the spring rings each have spring tongues which are arranged along and fixed to the inner circumference of an outer ring, this yields the advantage that the spring tongues are more easily deformable for example than disk springs with closed circular contours, such that the upper spring clip as seen in the installed state, or the first spring clip, can be clamped to the guide piece without a plastic deformation threshold being reached, that is to say within the range of elastic deformation. At the same time, a spring preload in an axial direction is provided during operation, so as to eliminate a clearance and to eliminate rattling noises.
If the spring tongues project from the outer ring at an obtuse angle, this yields the advantage that a spring action and a support surface are provided, from which support surface the spring tongues extend radially inward.
If the spring tongues are arranged with uniform spacings to one another, this yields the advantage of a uniform force distribution.
If the spring tongues are separated from one another by recesses, this yields the advantage that a variable width of the spring elements is made possible, which in turn yields the advantage that manipulation of the spring stiffness in an axial direction is made possible.
If the spring rings are in each case of identical form, this yields the advantage of a uniform load or preload from bottom to top as viewed in the installed state.
If the connecting bracket has a bracket contour which is matched to the outer contours of the free end region, this yields the advantage of space-saving installation. Furthermore, no sharp-edged objects project from the free end region.
In a further particularly preferred embodiment, the lower spring ring as seen in the installed state, or the second spring ring, is supported on an abutment plate of the guide piece, whereas the first or upper spring ring is clamped to a bolt of the guide piece. This yields the advantage that, after the upper spring ring has been clamped, an axial preload is provided.
Furthermore, it is optionally possible for radial tabs to be provided on the connecting bracket, which yields the advantage that the guide piece can additionally be spring-loaded in the radial direction of its bolt.
Finally, it is possible for the material of the spring clip according to the invention to be provided with a surface coating (preferably in the form of a slide coating) in order to reduce the friction between the spring clip and the free end region, which furthermore leads to a reduction in hysteresis.
The material thickness of the spring clip preferably lies in a range from 0.1 mm to 0.3 mm, in particular 0.12 mm to 0.18 mm.
Claim 15 defines a spring clip according to the invention as an independently marketable product of the control arrangement according to the invention.
Claim 16 defines a method for installing a regulating rod on a guide piece.
Further details, advantages and features of the present invention can be found in the following description of exemplary embodiments with reference to the drawing, in which:
a to 4d are schematically highly simplified illustrations of the spring clip according to the invention and of the guide piece, for the explanation of the installation method according to the invention.
The exhaust-gas turbocharger 1 furthermore has a regulating unit 4 as a component of a control arrangement 9. As shown in
The regulating unit 4 has a regulating rod 5 which comprises a free end region 8. The free end region 8 is connected to a guide piece 6. The guide piece 6 is fixed to an outer lever 7, which is connected to a control shaft 31 which is guided in the turbine housing 2. At its end region 32 arranged in the turbine housing 2, the control shaft 31 is connected to an inner lever 33. The inner lever 33 in turn is connected at its free end to a wastegate flap 3 which, by actuation by means of the regulating unit 4, can be pivoted between a closed position, shown in
The free end region 8 of the regulating rod 5 is connected to the guide piece 6 by means of a spring clip 10 which engages around the free end region 8 and which is clamped to the guide piece 6, as will be described in detail below on the basis of the illustrations of
As can be seen viewing
The spacing A, indicated in
Said spacing A is advantageously variable owing to the design of the connecting bracket, such that adaptations to different contours and dimensions of the free end region 8 are possible.
As can be seen in detail from
The spring tongues 11A to 11F and 12A to 12F are arranged along and fixed to an inner circumference IU14 and IU15 respectively of an outer ring 14 and 15 respectively.
In this case, the spring tongues 11A to 11F and 12A to 12F each enclose an obtuse angle and □ respectively with the associated outer rings 14 and 15 respectively, said angles each being indicated in
The lower spring ring 12 as seen in the installed state shown in
In the particularly preferred embodiment illustrated in
The illustration of
In this case, in the embodiment illustrated in
As is also shown in
Furthermore, the connecting bracket 13 may, as an optional feature, have radial tabs, of which a tab 17 is indicated by the dashed lines in
Below, the installation method according to the invention will be discussed on the basis of
After the spring clip 10 has been produced, for example by way of a bending and punching process, the spring clip 10 is, whilst still in the flat state, mounted by way of its spring ring 12 onto the connecting piece 6. Subsequently, the connecting bracket 13, which is indicated by the dashed lines in
In addition to the above written disclosure, reference is hereby explicitly made, for supplementation thereof, to the diagrammatic illustration of the invention in
| Number | Date | Country | Kind |
|---|---|---|---|
| 102014212581.2 | Jun 2014 | DE | national |
