Description

The present invention relates to a level sensor for detecting a movement of a suspen- sion arm relative to a framework of a vehicle according to the preamble of claim 1 and a vehicle assembly comprising a framework, a suspension arm mounted to said framework and a level sensor for detecting a movement of said suspension arm rela- tive to said framework according to the preamble of claim 8.

Such level sensors and vehicle assemblies are already known in different embodi- ments.

For example, from the DE 20 2004 014 323 U1 a vehicle assembly is known, compris- ing a framework, a suspension arm mounted to said framework and a level sensor for detecting a movement of said suspension arm relative to said framework. The level sensor used comprises a stator and a rotor relatively rotatable to said stator, whereat said stator is mounted to said framework and said rotor is linked to said suspension arm in a rotation transmitting manner via two lever arms.

It is an object of the invention to provide an improved level sensing for a suspension arm relative to a framework of a vehicle.

This object is solved by a level sensor for detecting a movement of a suspension arm relative to a framework of a vehicle according to claim 1 , wherein said connector is linked to said rotor in a rotation transmitting manner via a form-fit coupling. Further- more, that object is solved by a vehicle assembly, comprising a framework, a suspen- sion arm mounted to said framework and a level sensor for detecting a movement of said suspension arm relative to said framework according to claim 8, wherein said suspension arm is mounted to said framework in a rotatable manner via a hinge, corn- prising a hinge support and a hinge bolt, whereat said connector is linked to said hinge and said level sensor is built as a level sensor according to one of the claims 1 to 7.

A main advantage of the invention is to be robust and thus, the level sensor and the vehicle assembly employing the level sensor do have an enhanced durability even un- der severe environmental conditions. Furthermore, the invention can be realized with less tolerances because of less parts needed. Said form-fit coupling of the invention couples said connector and said rotor by interference and not by friction. Thus, said connector and said rotor are coupled in a definite and secure way, even under severe environmental conditions.

Further advantageous developments of the invention are apparent form the sub- claims as well as from the following description of exemplary embodiments of the in- vention by means of the attached Figures.

Basically, said level sensor can be of any suitable kind, function, shape, material, di- mension and position relative to said framework and said suspension arm of said vehi- cle. This is especially true for said form-fit coupling linking said connector to said rotor. Advantageously, said form-fit coupling is being built as a dog clutch. Dog clutches are suitable for preventing undesired slippage, thus said dog clutch is not affected by wear in the same way that other types of couplings are.

An alternative advantageous embodiment to the aforementioned embodiment is, that said form-fit coupling is being built as an Oldham coupling. An Oldham coupling is suitable to compensate for radial offset of said connector on the one side and said ro- tor on the other side.

Both form-fit couplings mentioned above, namely the dog clutch and the Oldham cou- pling, are quite easy to assemble. Thus, the inventive level sensor can be realized more easily. In general, the connector on the one side and the rotor on the other side can be cou- pled directly with each other. Advantageously, said form-fit coupling comprises an in- termediate part linking said connector and said rotor. Hereby, more freedom of design is achieved.

A particular advantageous development of the aforementioned embodiment is, that said intermediate part comprises a sealing for sealing joints between said intermediate part on one side and said connector and said rotor on the other side. That way, said joints between said intermediate part and said connector and between said intermedi- ate part and said rotor can be sealed without using any further parts for sealing said joints. Thus, the complexity of the inventive level sensor is reduced. For example, said sealing can be molded as an integral part of said intermediate part.

An advantageous development of the two last-mentioned embodiments of the in- ventive level sensor is, that said intermediate part is built from an elastic material or comprises at least one elastic part in contact with said connector and/or said rotor. On the one side, using an elastic material or an elastic part does compensate for some tolerances of said connector and said rotor. Furthermore, said elastic material or said elastic part does yield some extra sealing of said joints between said connector and said intermediate part and said intermediate part and said rotor. On the other side, in combination with the last-mentioned embodiment, said sealing for sealing joints is quite easy realized by using said elastic material or said elastic part. For example, said intermediate part made from an elastic material can be built as said sealing for said joints, too.

Another favorable development of the level sensor according to the invention is, that said connector comprises an alignment part for positioning said connector relative to said suspension arm. Hereby, said connector can be positioned relative to said sus- pension arm for an attachment of said connector to said suspension arm in a correct position. Furthermore, said alignment part can be used for power transmission and for transmitting a rotation from said suspension arm relative to said framework onto said connector and thus onto said rotor of said level sensor. Basically, said hinge and said link of said connector of said level sensor to said sus- pension arm can be of any suitable kind, shape, material, dimension and arrange- ment. Advantageously, said suspension arm comprises said hinge support and said framework comprises said hinge bolt, whereat said connector is being built as a lever arm and linked to said hinge support. That way, said hinge and said link of said con- nector of said level sensor to said suspension arm can be realized easily and in a compact design, too.

An alternative advantageous development to the embodiment mentioned before is, that said suspension arm comprises said hinge bolt and said framework comprises said hinge support, whereat said connector is being built as a lever arm and linked to an area of said suspension arm said hinge bolt is located in. Of course, it would also be possible, to link said connector not to said area of said suspension arm said hinge bolt is located in, but directly to said hinge bolt. Thus, no lever arm would be needed, but only a connector for transferring rotation from said suspension arm to said level sensor.

The Figures are schematic illustrations of a level sensor according to the invention and a vehicle assembly according to the invention comprising such a level sensor, wherein only the details necessary for the understanding of the invention are shown.

It is shown by:

Fig. 1 an embodiment of the vehicle assembly according to the invention in a par- tial top view,

Fig. 2 a first embodiment of the level sensor according to the invention in an ex- ploded view,

Fig. 3 parts of the first embodiment of the level sensor in different perspective views,

Fig. 4 the first embodiment of the level sensor in an assembly drawing,

Fig. 5 a detail of the first embodiment of the level sensor in a sectional view, Fig. 6 a second embodiment of the level sensor according to the invention in an exploded view,

Fig. 7 parts of the second embodiment of the level sensor in different perspective views,

Fig. 8 the second embodiment of the level sensor in an assembly drawing and Fig. 9 a detail of the second embodiment of the level sensor in a sectional view.

Fig. 1 displays an embodiment of the inventive vehicle assembly in a partial top view. Said vehicle assembly comprises a framework 2 of a vehicle, a suspension arm 4 mounted to said framework 2 and a level sensor 6 for detecting a rotation of said sus- pension arm 4 relative to said framework 2. Said vehicle is not displayed. Said sus- pension arm 4 is used for supporting a wheel of said vehicle. Said wheel is not dis- played, too. Said suspension arm 4 is mounted to said framework 2 in a rotatable manner via a hinge 8, comprising a hinge support 8.1 and a hinge bolt 8.2. Said sus- pension arm 4 comprises said hinge support 8.1 and said framework 2 comprises said hinge bolt 8.2. Said level sensor 6 is fixed to said framework 2 and comprises a con- nector 10 for linking said level sensor 6 to said suspension arm 4 in a rotation trans- mitting manner, whereat said connector 10 is being built as a lever arm 10 and linked to said hinge support 8.1 of said hinge 8. Said suspension arm 4 with said hinge sup- port 8.1 is rotatable around said hinge bolt 8.2 of said framework 2 in both directions, as symbolized by double arrow 12. Said lever arm 10 is rotatable around a rotation axis 14 of said level sensor 6 in both directions, as symbolized by double arrow 16.

Said level sensor 6 according to a first embodiment is further explained by using Fig. 2 to 5.

In Fig. 2 said level sensor 6 is shown in an exploded view. Said level sensor 6 is built as a inductive sensor and comprises said lever arm 10, an intermediate part 18, a ro- tor 20 and a stator, which is not displayed. Said stator is fixed to a housing 22, which is fixed to said framework 2 via a mounting assembly 24. Said rotor 20 is rotatable around said rotation axis 14 of said level sensor 6 relative to said stator. Said con- nector 10, namely said lever arm 10, is linked to said rotor 20 in a rotation transmitting manner via a form-fit coupling, namely a dog clutch 26. Said dog clutch 26 is built via said connector 10, said intermediate part 18 and said rotor 20.

Said intermediate part 18 is made from an elastic material, namely rubber, and does have three recesses 18.1 on the side of said lever arm 10 and three recesses 18.2 on the side of said rotor 20. Said lever arm 10 and said rotor 20 do have three protrusions 10.1 , 20.1 each on the sides facing said intermediate part 18. Said protrusions 10.1 of said lever arm 10 and said recesses 18.1 of said intermediate part 18 as well as said protrusions 20.1 of said rotor 20 and said recesses 18.2 of said intermediate part 18 are corresponding to each other in order to build a form-fit coupling between said lever arm 10 and said intermediate part 18 as well as between said intermediate part 18 and said rotor 20. See Fig. 2 and 3. Thus, a form-fit coupling between said lever arm 10 linked to said suspension arm 4 and said rotor 20 rotatable relative to said stator of said level sensor 6 mounted to said framework 2 is established. See Fig. 5. Fig. 5 is a sectional view according to the cut line displayed in Fig. 4.

Said intermediate part 18 is further built as a sealing for sealing joints between said in- termediate part 18 and said lever arm 10 as well as between said intermediate part 18 and said rotor 20 of said level sensor 6. Therefor, said intermediate part 18 comprises two shoulders 18.3 covering said before mentioned joints; see Fig. 4 and 5.

Said lever arm 10 comprises an alignment part 10.2 for positioning said lever arm 10 relative to said suspension arm 4. Said alignment part 10.2 is built as a positioning bolt 10.2 which is in engagement with a corresponding hole in said hinge support 8.1 of said hinge 8. Furthermore, said lever arm 10 comprises a screw hole 10.3 for a screw 28 in order to fix said lever arm 10 to said hinge support 8.1 of said hinge 8. Therefor, said hinge support 8.1 comprises a screw hole corresponding to said screw 28, too. Said aforementioned holes of said hinge support 8.1 are not displayed. In the following, the function of said embodiment of the inventive vehicle assembly with the first embodiment of the inventive level sensor is explained by means of Fig. 1 to 5.

Said vehicle drives along a driving path of a road. Said driving path and said road are not displayed. Said wheel which is supported by said suspension arm 4 is moving rel- ative to said framework 2, thus said suspension arm 4 is rotating around said hinge bolt 8.2 via said hinge support 8.1 of said hinge 8. Because of said rotation of said hinge support 8.1 said lever arm 10 linked to said hinge support 8.1 is rotated around said rotation axis 14 of said level sensor 6. Said lever arm 10 is coupled to said rotor 20 via said dog clutch 26, thus said rotor 20 rotates around said rotation axis 14 rela- tive to said stator of said level sensor 6. That way, said rotation of said suspension arm 4 relative to said framework 2 is measured via said level sensor 6 for further use in controlling said vehicle.

Fig. 6 to 9 display a second embodiment of the inventive level sensor usable with the inventive vehicle assembly according to Fig. 1. In the following, only differences be- tween the second embodiment and the first embodiment according to the Fig. 2 to 5 are discussed. Similar or equal parts are referred to with the same reference numbers in the Figures. Because of the fact, said only the form-fit coupling of the inventive level sensor according to the second embodiment is modified in comparison to the first em- bodiment of the inventive level sensor explained via Fig. 1 to 5, Fig. 1 and the expla- nations with respect to Fig. 1 according to the first embodiment of the inventive level sensor are true for the second embodiment of the inventive level sensor, too.

In Fig. 6 said level sensor 6 of the second embodiment is shown in an exploded view. Instead of using a dog clutch as a form-fit coupling said form-fit coupling is being built as an Oldham coupling 26. Like said dog clutch according to the first embodiment, said Oldham coupling 26 of the second embodiment is built via said connector 10, said intermediate part 18 and said rotor 20. Said intermediate part 18 is made from an elastic material, namely rubber, and does have one recess 18.1 on the side of said lever arm 10 and one recess 18.2 on the side of said rotor 20. Said lever arm 10 and said rotor 20 do have one protrusion 10.1 , 20.1 each on the sides facing said interme- diate part 18. Said protrusion 10.1 of said lever arm 10 and said recess 18.1 of said intermediate part 18 as well as said protrusion 20.1 of said rotor 20 and said recess

18.2 of said intermediate part 18 are corresponding to each other in order to build a form-fit coupling between said lever arm 10 and said intermediate part 18 as well as between said intermediate part 18 and said rotor 20. See Fig. 6 and 7. Thus, a form-fit coupling between said lever arm 10 linked to said suspension arm 4 and said rotor 20 rotatable relative to said stator of said level sensor 6 mounted to said framework 2 is established. See Fig. 9. Fig. 9 is a sectional view according to the cut line displayed in Fig. 8.

As with the first embodiment, said intermediate part 18 is further built as a sealing for sealing joints between said intermediate part 18 and said lever arm 10 as well as be- tween said intermediate part 18 and said rotor 20 of said level sensor 6. Therefor, said intermediate part 18 comprises two shoulders 18.3 covering said before mentioned joints; see Fig. 8 and 9. Unlike the first embodiment of said level sensor 6, said seal- ing, namely said shoulders 18.3, is built as a concertina type cover. Said shoulders

18.3 of said intermediate part 18 are not displayed in Fig. 7.

Besides the above mentioned aspects, said level sensor 6 according to the second embodiment is designed substantially equal to said first embodiment discussed be- fore. For the rest of the design and function of the inventive level sensor 6 according to the second embodiment it can be referred to the explanations according to the first embodiment, which are included in total for the explanation of the second embodi- ment.

The invention is not limited to the exemplary embodiments of the level sensor and the vehicle assembly discussed above. The form-fit coupling according to the invention can also be done in a direct way, namely without using an intermediate part. Of course, the form-fit coupling is not limited to dog clutches or Oldham couplings. Fur- thermore, the sealing for sealing joints between said intermediate part on one side and said connector and said rotor on the other side can be designed as a separate part, too. Thus, the sealing does not have to be linked to or made out of the intermediate part or any other part of the form-fit coupling according to the invention. The intermedi- ate part does not have to be made in total from an elastic material, but at least one elastic part of said intermediate part in contact with said connector and/or said rotor is also possible. For example, said elastic part could be molded to a rest of said interme- diate part.

As already mentioned, said hinge and said link of said connector of said level sensor to said suspension arm can be of any suitable kind, shape, material, dimension and arrangement. For example, an alternative advantageous development to the embodi- ments explained is, that said suspension arm comprises said hinge bolt and said framework comprises said hinge support, whereat said connector is being built as a lever arm and linked to an area of said suspension arm said hinge bolt is located in. Of course, it would also be possible, to link said connector not to said area of said sus- pension arm said hinge bolt is located in, but directly to said hinge bolt.

List of reference numbers

2 Framework

4 Suspension arm

6 Level sensor

8 Hinge

8.1 Hinge support

8.2 Hinge bolt

10 Connector, built as a lever arm

10.1 Protrusion of connector 10

10.2 Alignment part of connector 10

10.3 Screw hole of connector 10

12 Rotation of suspension arm 4 14 Rotation axis of level sensor 6 16 Rotation of connector 10

18 Intermediate part

18.1 Recess of intermediate part 18

18.2 Recess of intermediate part 18

18.3 Shoulder of intermediate part 18

20 Rotor of level sensor 6

20.1 Protrusion of rotor 20

22 Housing, with stator of level sensor 6

24 Mounting assembly

26 Form-fit coupling

28 Screw