STEERING COLUMN FOR A MOTOR VEHICLE

Abstract

A steering column may include a casing unit in which a steering spindle is rotatably mounted about a longitudinal axis and which has at least three telescopically guided casing tubes that are mutually adjustable in an axial direction. One of the tubes is an external casing tube in which an intermediate casing tube is received, an internal casing tube being received in the intermediate casing tube. A locking bolt installation can releasably lock at least two of the casing tubes to one another in the direction of the longitudinal axis. The locking bolt installation can switch between an internal blocking position and an external blocking position. The intermediate casing tube in the internal blocking position is locked to the internal casing tube. The intermediate casing tube in the external locking position is locked to the external casing tube.

Claims

1.-10. (canceled)

11. A steering column for a motor vehicle comprising: a casing unit in which a steering spindle is mounted so as to be rotatable about a longitudinal axis, the casing unit having at least three telescopically guided casing tubes that are mutually adjustable in an axial direction, wherein one of the at least three telescopically guided casing tubes is an external casing tube in which an intermediate casing tube is received, wherein an internal casing tube is received in the intermediate casing tube; and a locking bolt installation for releasably locking at least two of the at least three telescopically guided casing tubes to one another in a direction of the longitudinal axis, wherein the locking bolt installation is switchable between an internal blocking position and an external blocking position, wherein in the internal blocking position the intermediate casing tube is locked to the internal casing tube, wherein in the external blocking position the intermediate casing tube is locked to the external casing tube.

12. The steering column of claim 11 wherein at least one of: the internal casing tube has an activation means for switching the locking bolt installation to the external blocking position; or the external casing tube has an activation means for switching the locking bolt installation to the internal blocking position.

13. The steering column of claim 12 wherein at least one of: the activation means of the internal casing tube, as a function of a predefined first relative position of the intermediate casing tube and the external casing tube, is configured to switch the locking bolt installation to the external blocking position; or the activation means of the external casing tube, as a function of a predefined second relative position of the intermediate casing tube and the external casing tube, is configured to switch the locking bolt installation to the internal blocking position.

14. The steering column of claim 11 wherein the locking bolt installation includes a locking element that is mounted so as to be movable on the intermediate casing tube, wherein the locking element is at least one of: engageable with an external locking bolt receptacle on the external casing tube in the external blocking position; or engageable with an internal locking bolt receptacle on the internal casing tube in the internal blocking position.

15. The steering column of claim 14 wherein the locking element radially penetrates the intermediate casing tube and is mounted in the intermediate casing tube so as to be radially movable.

16. The steering column of claim 14 wherein the locking element is configured to interact with at least one of: an activation means disposed on the external casing tube such that a relative movement between the intermediate casing tube and the external casing tube causes the locking element to move to the internal blocking position; or an activation means disposed on the internal casing tube such that a relative movement between the intermediate casing tube and the external casing tube causes the locking element to switch to the external blocking position.

17. The steering column of claim 14 wherein the locking element comprises: an internal head configured to be disposed from an outside into the internal locking bolt receptacle; and an external head configured to be disposed from an inside into the external locking bolt receptacle.

18. The steering column of claim 17 wherein the internal head and/or the external head has an activation ramp that interacts with a corresponding activation element configured on the internal casing tube or the external casing tube.

19. The steering column of claim 14 wherein the intermediate casing tube and at least one of the internal casing tube or the external casing tube have corresponding longitudinal detents that can impact one another in the direction of the longitudinal axis.

20. The steering column of claim 14 wherein the locking element is spring-loaded in the external blocking position or the internal blocking position.

Description

DESCRIPTION OF THE DRAWINGS

[0036] Advantageous embodiments of the invention will be explained in more detail hereunder by means of the drawings in which, in detail:

[0037] FIG. 1 shows a steering column according to the invention in a schematic perspective view;

[0038] FIG. 2 shows an enlarged detailed view of FIG. 1 in the region of the locking bolt installation;

[0039] FIG. 3 shows a longitudinal section along the longitudinal axis through the steering column according to FIG. 1 in the stowage position (=retracted/collapsed state)

[0040] FIG. 4 shows an enlarged detailed view of FIG. 3 in the region of the locking bolt installation;

[0041] FIG. 5 shows a longitudinal section along the longitudinal axis through the steering column according to FIG. 1 in the operating position (=deployed state);

[0042] FIG. 6 shows an enlarged detailed view of FIG. 5 in the region of the locking bolt installation.

EMBODIMENTS OF THE INVENTION

[0043] Identical parts in the various figures are always provided with the same reference signs and are therefore typically also identified or mentioned, respectively, in each case only once.

[0044] FIG. 1 shows a steering column 1 according to the invention in a perspective view from obliquely behind, with respect to the direction of travel, in FIG. 3 in a longitudinal section in the stowage position in the maximum retracted or collapsed state, respectively, and in FIG. 5 in the same sectional view as in FIG. 3 in a possible operating or operative position, respectively, in a deployed state. FIGS. 2, 4 and 6 show enlarged partial views of FIGS. 1, 3 and 5.

[0045] The steering column 1 has an actuator unit 2. The actuator unit 2 comprises a casing unit 3 having three casing tubes 31, 32, 33, specifically an external casing tube 31, an intermediate casing tube 32, and an internal casing tube 33. The casing tubes 31, 32 and 33 are disposed so as to be coaxial inside one another, and are telescopically displaceable in the longitudinal direction, the latter corresponding to the axial direction of a longitudinal axis L, as is indicated by the double arrow. The one direction in which the casing tubes 31, 32, 33 can be conjointly moved into one another, i.e. retracted, to the stowage position in order for the actuator unit 2 to be shortened, is the retraction direction E, and correspondingly the direction counter thereto, in which the casing tubes 31, 32, 33 are moved apart, i.e. deployed, from the stowage position in the direction of an operating position is the deployment direction A, as is indicated by the respective arrows.

[0046] A steering spindle 4 which at the rear end thereof has a connector portion 41 for attaching a steering wheel, not illustrated, is mounted in the casing unit 3 so as to be rotatable about a longitudinal axis L. The steering spindle 4 is likewise configured so as to be telescopic in the axial direction, having an external shaft 42 configured as a hollow shaft into which an internal shaft 43 plunges so as to be telescopically displaceable in the axial direction. The internal shaft 43 and the external shaft 42 are connected to one another in a torque-fitting manner by way of a longitudinally displaceable coupling 44, the latter in a manner known per se, by way of non-round cross sections, longitudinal toothings or the like, generating a rotationally fixed connection which is displaceable in the axial direction. The external shaft 42 in the internal casing tube 33 is mounted in a bearing 45 which preferably has roller bearings. The internal shaft 43 can be rotatably mounted in the external casing tube. The internal shaft 43 can preferably be able to be connected to a shaft of a feedback actuator. Alternatively, the internal shaft 43 can also be able to be coupled to a steering layshaft which in turn is coupled in a torque-fitting manner to an input shaft of a steering gear, wherein the steering layshaft preferably comprises at least one universal joint.

[0047] The casing unit 3 is held in a two-part support unit 5 which has fastening means 51 for attaching to a vehicle body which is not illustrated.

[0048] An adjustment drive 6 has a spindle drive having a spindle nut 61 and a threaded spindle 62 which is screwed into the latter, said spindle nut 61 and said threaded spindle 62 being able to be rotationally driven relative to one another by an electric motor 63. The threaded spindle 62 extends parallel to the longitudinal axis L and is connected to the internal casing tube 33, and the spindle nut 61 by way of the adjustment drive 6 is supported in the longitudinal direction on the external casing tube 31, said longitudinal direction corresponding to the axial direction of the longitudinal axis L. Depending on the direction of rotation, the threaded spindle 62 and the spindle nut 61 are moved so as to converge or diverge as a result of a relative rotation by means of the motor 63, as a result of which the internal casing tube 33 in the axial direction can either be retracted in the retraction direction E into the external casing tube 31, or counter thereto be deployed in the deployment direction A from the external casing tube 31. As a result, a longitudinal adjustment is implemented as a result of which a steering wheel attached to the connector portion 41 can be selectively brought forward to the stowage position illustrated in FIG. 5, in which the internal casing tube 33 and the intermediate casing tube 32 are retracted into the external casing tube 31, i.e. are lowered forward into the latter, or be brought rearward to an operating position illustrated in FIG. 1 or FIG. 3, in which the casing tubes 31, 32, and 33 are deployed from one another. A first friction sleeve 301 can optionally be disposed between the external casing tube 31 and the intermediate casing tube 32, and an optional second friction sleeve 302 can be disposed between the intermediate casing tube 32 and the internal casing tube 33. The friction sleeves 301, 302 can have clearances or grooves, the locking pin 71 of the locking bolt installation 7 extending through said clearances or grooves. The friction sleeves 301, 302 are preferably formed from a plastics material.

[0049] Alternatively, the spindle nut 61 can be supported on the internal casing tube 33, and the threaded spindle 62 can be supported on the external casing tube 31.

[0050] An operating position of the steering column 1 in which the intermediate casing tube 32 and the internal casing tube 33 are at least partially moved out of the external casing tube 31 in the deployment direction A, to the right in the drawing, such that a steering wheel that is able to be attached to the connector portion 41 is situated in the operating region for inputting steering commands, is shown in FIG. 3. FIG. 5 in the same sectional view shows the stowage position in which the intermediate casing tube 32 and the internal casing tube 33 are pushed to the maximum in the retraction direction E into the external casing tube 31. As a result, the steering wheel 1 is shortened to the maximum in the axial direction such that the steering wheel, for example in the autonomous driving operation or so as to facilitate ingress and egress in the case of a parked vehicle, can be stowed outside the operating region.

[0051] A locking bolt installation 7 according to the invention comprises a locking element configured as a locking pin 71 which in the intermediate casing tube 32 is mounted so as to be movable transversely to the longitudinal axis L, i.e. in the radial direction, and so as to be supported in the axial direction of the longitudinal axis L. The locking pin 71, while sliding in a guide opening, penetrates the wall of the intermediate casing tube 32, and has an outwardly projecting external head 711 and an inwardly projecting internal head 713, the latter having an inclined control face 751. As a result of a spring element 72, for example a coil spring, which is externally supported in relation to the intermediate casing tube 32 and engages on the locking pin 71, the locking pin 71 with respect to the longitudinal axis L is elastically preloaded in a radially outward manner by a spring force F, as is indicated in FIGS. 4 and 6.

[0052] The locking pin 71 in an external blocking position as is illustrated in FIGS. 2, 3 and 4, with respect to the intermediate casing tube 32 is displaced in a radially outward manner. The external head 711 here protrudes so far outward that said external head 711 interacts with an external locking bolt receptacle 73 configured on the external casing tube 31. The external locking bolt receptacle 73 has an inclined axial face 74 which represents an activation means in the context of the invention. The external head 711 has an activation ramp 75 which in the example shown is inclined downward at an angle of approximately 45° in the retraction direction E toward the longitudinal axis L.

[0053] In the external blocking position, the intermediate casing tube 32 is locked by way of the external locking bolt receptacle 73 to the external casing tube 31 in such a manner that said intermediate casing tube 32 cannot be retracted in the retraction direction E into the external casing tube 31, whereby a further deployment in the deployment direction A of the intermediate casing tube 32 from the external casing tube 31 is possible. The internal casing tube 33 here can be moved in a telescopic manner without impediment in the intermediate casing tube 32.

[0054] The internal casing tube 33 has an internal locking bolt receptacle 76 in the form of a wedge-shaped opening in which the locking pin 71 in the internal blocking position illustrated in FIG. 6, in which said locking pin 71 with respect to the intermediate casing tube 32 is repositioned in a radially inward manner, engages by way of the internal head 713 of said locking pin 71. As a result, a form-fitting connection effective in the axial direction is generated, the internal casing tube 33 being locked to the intermediate casing tube 32 in the axial direction (longitudinal direction) by said form-fitting connection.

[0055] In the internal blocking position, the intermediate casing tube 32 is locked by way of the internal locking bolt receptacle 73 to the internal casing tube 33 in such a manner that said intermediate casing tube 32 cannot be moved in a mutually relative manner either in the retraction direction E or in the deployment direction A. The intermediate casing tube 32, conjointly with the internal casing tube 33 locked to the former, here can be moved in a telescopic manner without impediment in the external casing tube 31.

[0056] As a result of the locking pin 71 being able to be moved to the external blocking position or internal blocking position, switching of the locking bolt installation 7 according to the invention can be effected, said switching ensuring a defined sequence when telescopically retracting or deploying the casing tubes 31, 32, 33, as will be explained hereunder.

[0057] In order for the steering column 1 to be brought from the deployed operating position illustrated in FIG. 3, for example during autonomous driving, to the stowage position shown in FIG. 5, an adjustment force in the retraction direction E is exerted on the internal casing tube 33 by the adjustment drive 6. The locking bolt installation 7 which is situated in the external blocking position, by way of the external head 711 of the locking pin 71 that in a form-fitting manner lies against the external locking bolt receptacle 73, here prevents that the intermediate casing tube 32 can be retracted into the external casing tube 31. The locking pin 71 here, by way of the internal head 713 thereof, is supported from the outside in relation to the internal casing tube 33 in such a manner that said locking pin 71 cannot exit the external blocking position. Therefore, only the internal casing tube 33 can initially be retracted into the intermediate casing tube 32.

[0058] When the internal casing tube 33 has been fully retracted into the intermediate casing tube, the locking pin 71 and the internal locking bolt receptacle 76 are situated at the same position. As a result of a longitudinal detent 34, the latter being disposed on the internal casing tube 33 and having an axial detent face which in the retraction direction E is directed toward the intermediate casing tube 32, impacting an axially opposite detent face of a corresponding longitudinal detent 35 on the intermediate casing tube 32, the adjustment force of the adjustment drive 6 is effective between the activation ramp 75 of the external head 701 and the axial face 74 of the external locking bolt receptacle 73 that lies against said activation ramp 75. The switching of the locking bolt installation 7 is effected in that the activation ramp 75 and the axial face 74 form a cam mechanism. The adjustment force acting in the axial direction is deflected by this cam mechanism and transmitted in the radial direction to the locking pin 71 in such a manner that the latter counter to the spring force F is moved radially inward from the external blocking position until said locking pin 71 assumes the internal blocking position illustrated in FIG. 6. The internal head 713, which moves inward, plunges here in a form-fitting manner into the internal locking bolt receptacle 76.

[0059] As a result of the self-acting switching described, the internal casing tube 33 is now locked to the intermediate casing tube 32, and the locking between the intermediate casing tube 32 and the external casing tube 31 is simultaneously released. Consequently, the intermediate casing tube 32, conjointly with the internal casing tube 33 situated therein, as a result of the adjustment force exerted in the retraction direction E is retracted into the external casing tube 31 until the terminal position illustrated in FIG. 5, thus the stowage position, is reached.

[0060] The sequence in which the casing tubes 31, 32, 33 are mutually moved is unequivocally established as a result of the conditional locking, such that non-defined adjustment states can be reliably avoided.

[0061] In order for the steering column 1 to be brought from the stowage position to the operating position, an adjustment force in the deployment direction A is exerted on the internal casing tube 33 by the adjustment drive 6 in FIG. 5. Thereafter, only the intermediate casing tube 32 that is locked to the internal casing tube 33 can initially be moved out of the external casing tube 31.

[0062] Once the locking pin 71 reaches the position shown in FIG. 3, said locking pin 71 as a result of the spring force F of the spring element 72 is moved in a self-acting manner from the internal blocking position to the external blocking position according to FIG. 4 such that the locking bolt installation 7 is switched. It is only then that the internal casing tube 33 can be deployed from the intermediate casing tube 32. Alternatively, the spring element 72 can also be omitted. As a result of an inclined control face 761 of the internal locking bolt receptacle 76, the locking pin 71 which by way of the counter-control face 751 configured on the internal head 713 interacts with the control face and provides a can mechanism, is transferred from the internal blocking position to the external blocking position when the movement of the locking pin 71 is no longer prevented by the external casing 31 and said locking pin 71 can engage in the external locking bolt receptacles. In other words, as a result of the inclined control face and counter-control face, the force acting in the direction of the longitudinal axis is converted to a lifting movement of the locking pin 71.

[0063] Two or more locking bolt installations 7 are preferably disposed so as to be distributed across the circumference, as is illustrated.

[0064] The casing tubes 31, 32, 33 preferably have extraction safeguards 36 which comprise axial detents that project radially on the outside of an inner casing tube 32, 33 and interact with axial detents that project radially inward on the corresponding outer casing tubes 31, 32 in such a manner that said axial detents impact one another in the event of a predefined extraction, thus preventing that the casing tubes 31, 32, 33 are excessively extracted or separated, whereby the extraction safeguards in an impact situation are supported on the friction sleeves 301, 302.

LIST OF REFERENCE SIGNS

[0065] 1 Steering column [0066] 2 Actuator unit [0067] 3 Casing unit [0068] 31 External casing tube [0069] 311 Raceway [0070] 32 Intermediate casing tube [0071] 321 Raceway [0072] 33 Internal casing tube [0073] 34, 35 Longitudinal detent [0074] 36 Extraction safeguards [0075] 4 Steering spindle [0076] 41 Connector portion [0077] 42 External shaft [0078] 43 Internal shaft [0079] 44 Coupling [0080] 45 Bearing [0081] 5 Support unit [0082] 51 Fastening means [0083] 6 Adjustment drive [0084] 61 Spindle nut [0085] 62 Threaded spindle [0086] 63 Motor [0087] 7 Locking bolt installation [0088] 71 Locking pin [0089] 711 External head [0090] 713 Internal head [0091] 72 Spring element [0092] 73 External locking bolt receptacle [0093] 74 Axial face (activation means) [0094] 75 Activation ramp [0095] 76 Internal locking bolt receptacle [0096] L Longitudinal axis [0097] E Retraction direction [0098] A Deployment direction [0099] F Spring force