Abstract
A steering shaft may include an inner shaft at least partially within an outer shaft where the inner shaft includes a sliding element with an outer profile portion. The outer shaft may be displaced relative to the inner shaft axially in a direction of a longitudinal axis between a storage position and an operating position. A steering column may include an inner covering pipe in which such a steering shaft is rotatably supported and an outer covering unit in which the inner covering pipe is retained. The outer shaft may have a bearing means having an inner profile portion that corresponds to the outer profile portion. In the storage position the outer profile portion is at least partially received in the bearing means.
Claims
1.-14. (canceled)
15. A steering shaft for a steering column of a motor vehicle, the steering shaft comprising: an inner shaft with a sliding element having an outer profile portion; and an outer shaft in which the inner shaft is at least partially disposed, wherein the outer shaft is configured to be displaced relative to the inner shaft axially in a direction of a longitudinal axis between a storage position and an operating position, wherein the outer shaft includes a bearing means having an inner profile portion that corresponds to the outer profile portion, wherein in the storage position the outer profile portion is at least partially received in the bearing means.
16. The steering shaft of claim 15 wherein the bearing means is received in the outer shaft such that the bearing means is rotatable about the longitudinal axis.
17. The steering shaft of claim 15 wherein the bearing means is a sleeve.
18. The steering shaft of claim 15 wherein the outer shaft and the inner shaft are connected in a positive-locking manner for transmitting torque in the operating position.
19. The steering shaft of claim 15 wherein the outer shaft has a positive-locking portion for a positive-locking connection to the sliding element on the inner shaft in the operating position.
20. The steering shaft of claim 19 wherein the positive-locking portion comprises a shaping of the outer shaft.
21. The steering shaft of claim 15 wherein the bearing means comprises metal or plastic.
22. The steering shaft of claim 15 wherein the sliding element is a profile sleeve that is connected to the inner shaft in a non-movable manner.
23. The steering shaft of claim 15 wherein the sliding element is an overmolding of the inner shaft.
24. The steering shaft of claim 15 wherein the bearing means includes positioning means for flush positioning of the outer profile portion with the inner profile portion along the longitudinal axis.
25. The steering shaft of claim 24 wherein the positioning means is a projection.
26. The steering shaft of claim 15 wherein the outer shaft is disposed in a latching star-like member for a steering lock.
27. The steering shaft of claim 26 wherein the latching star-like member has a hollow profile with a longitudinal axis and locking recesses, wherein the locking recesses are configured to engage with a locking bar of the steering lock that is movable into a locking position or an unlocking position.
28. A steering column for a motor vehicle, the steering column comprising: an inner covering pipe; a steering shaft rotatably supported in the inner covering pipe, wherein the steering shaft comprises: an inner shaft with a sliding element having an outer profile portion, and an outer shaft in which the inner shaft is at least partially disposed, wherein the outer shaft is configured to be displaced relative to the inner shaft axially in a direction of a longitudinal axis between a storage position and an operating position, wherein the outer shaft includes a bearing means having an inner profile portion that corresponds to the outer profile portion, wherein in the storage position the outer profile portion is at least partially received in the bearing means; and an outer covering unit in which the inner covering pipe is retained.
29. The steering column of claim 28 wherein the bearing means is received in the outer shaft such that the bearing means is rotatable about the longitudinal axis.
30. The steering column of claim 28 wherein the bearing means is a sleeve.
31. The steering column of claim 28 wherein the outer shaft and the inner shaft are connected in a positive-locking manner for transmitting torque in the operating position.
32. The steering column of claim 28 wherein the outer shaft has a positive-locking portion for a positive-locking connection to the sliding element on the inner shaft in the operating position.
33. The steering column of claim 32 wherein the positive-locking portion comprises a shaping of the outer shaft.
34. The steering column of claim 28 wherein the sliding element is a profile sleeve that is connected to the inner shaft in a non-movable manner.
Description
[0042] The figures of the drawings show in detail:
[0043] FIG. 1: is a schematic illustration of a steering system;
[0044] FIG. 2: is a perspective illustration of a steering column according to the invention;
[0045] FIG. 3: is a longitudinal section of a steering column according to the invention in the state for manual operation (operating position);
[0046] FIG. 4: shows the steering column of FIG. 3 as a cross section through the upper cover;
[0047] FIG. 5: is a longitudinal section of the steering column according to FIG. 3 in the state for autonomous operation (storage position);
[0048] FIG. 6: is a cut-out from FIG. 5 with the locking element locked;
[0049] FIG. 7: is a component illustration of the inner shaft and outer shaft.
[0050] FIG. 1 is a schematic illustration of a steering system for a motor vehicle. This comprises a steering column 1 which is connected via an intermediate steering shaft 17 to a steering gear mechanism 23. The steering column 1 has a steering shaft 26, to the rear end of which when viewed in the travel direction a steering wheel 3 is fitted. The steering shaft 26 comprising an outer shaft 4 and an inner shaft 5 is coupled to an intermediate steering shaft 17 in a torque-conducting manner, wherein this intermediate steering shaft 17 is further coupled to a steering gear mechanism 23. The steering drive 16, 19 which is constructed as an electromechanical servo unit comprises an adjustment motor and may be arranged at various locations of the steering system for example, on the steering column 1 or on the steering gear mechanism 23, wherein generally only one steering drive in the form of an electromechanical servo unit is provided. A steering adjustment torque is converted by means of a pinion 25 and a toothed rack 24 into a translation movement of tie rods 22, whereby a steering angle of the steered wheels 21 is brought about.
[0051] FIG. 2 is a perspective illustration of an installed embodiment of a steering column 1 according to the invention. An upper cover 8, which is constructed as an inner cover, can be introduced into a lower cover 9 which is constructed as an outer cover, whereby a storage of a steering wheel 3 which is not illustrated here in a retracted first position is enabled. In the stored state, the upper cover 8 is introduced to the greatest possible extent into the lower cover 9. For axial displacement of the upper cover 8, a longitudinal adjustment drive 28 which drives a threaded rod 29 is provided. The longitudinal adjustment drive 28 comprises an electric motor 281 and a gear unit 282. The steering wheel 3 can be coupled to an outer shaft 4 of a steering shaft which is rotatably supported within the upper cover 8 and which can be rotated during rotation about a rotation axis 27. In the stored position of the steering column, the rotatability thereof is blocked by means of a locking device 2 which has a locking element 10. The locking element 10 is arranged via a spring 12 on the lower cover 9 and guided therein so as to be able to be displaced in a direction orthogonal to the rotation axis 27.
[0052] The lower cover 9 is preferably supported by a console 100, wherein the console can be connected to the motor vehicle. There is provided between the console 100 and the lower cover 9 a motorized height adjustment drive 101 which is configured so as to pivot the cover 9 with respect to the console 100 about a pivot axis and consequently to produce a height adjustment.
[0053] FIG. 3 illustrates an embodiment of a steering column 1 according to the invention as a longitudinal section in the state for manual operation in an operating position, in accordance with the second position of the upper cover 8. In this state, the steering column, or more specifically the upper cover 8 is located in a non-stored position, the upper cover 8 is extended with respect to the lower cover 9. The outer shaft 4 of the steering shaft is rotatably supported by means of a bearing 30 within the upper cover 8, wherein the bearing 30 is constructed as a roller bearing. An inner shaft 5 is also arranged inside the upper cover 8. This is arranged at an axial end 34 in a first portion 31 of the outer shaft 4 and can be releasably connected thereto. In the illustrated manual operating state of the steering column 1, the outer shaft 4 and inner shaft 5 are connected in a torque-conducting manner so that both rotate when the steering wheel 3 is rotated about a common rotation axis 27. A sleeve 15 is coaxially arranged within a second portion 32 of the outer shaft 4, wherein it is received in the outer shaft 4. As an additional component of the locking device 2, there is arranged on the outer shaft 4 a coupling element 6 which radially surrounds the outer shaft 4. The locking element 10 is pretensioned by means of a spring 12 and in the non-locked state, that is to say, when the locking element 10 and coupling element 6 are not brought into engagement. The locking element 10 is displaceably guided in an opening 900 of the outer cover 9.
[0054] FIG. 4 shows the steering column 1 from FIG. 3 as a cross section along the line A-A which is illustrated in FIG. 3. The outer shaft and inner shaft 4, 5 which are arranged radially partially inside each other and the upper cover 8 which surrounds it and the lower cover 9 which partially axially surrounds it are illustrated. Also illustrated is the sleeve 15 which is produced in such a manner that it can be received in a rotationally secure manner the inner shaft 5 when the inner shaft 5 is introduced into the outer shaft 4. In the embodiment illustrated, the coupling element 6 is constructed as a latching star-like member and radially surrounds the outer shaft 4. A positive-locking element 7 is constructed in the form of a rectangular groove 35 on the coupling element 6. The latching star-like member may preferably be constructed as an extruded component or shaped component.
[0055] In FIG. 5, the steering column of FIG. 3 is illustrated in longitudinal section in the state for autonomous operation. In this illustration, the upper cover 8 is in a storage position and the steering shaft is in a locked and uncoupled position. The upper cover 8 is inserted into the lower cover 9. Consequently, the axial end 34 of the inner shaft 5 is now arranged in a second portion 32 of the outer shaft and is introduced at that location into the sleeve 15 and connected in a rotationally secure manner thereto. A rotation of the inner shaft 5 now brings about a rotation of the sleeve 15 which can in turn be rotated relative to the outer shaft 4 by means of the acting torque. A rotation of the outer shaft and inner shaft 4, 5 is accordingly in the illustrated position mutually uncoupled so that the outer shaft 4 can be rotated relative to the inner shaft 5. The inner shaft 5 is during a steering maneuver rotated by the servo unit in the form of a steering drive. As a result of the solution according to the invention, however, the outer shaft does not also rotate. This is rotationally stationary. The inner shaft 5 rotates in this instance together with the sleeve 15, where it rotates relative to the outer shaft 4. As a result of the axial displacement of the upper cover 8 and the outer shaft 4 relative to the lower cover 9 and the inner shaft 5, the coupling element 6 is moved to an axial height with the locking element 10. The upper cover 8 accordingly has at the axial position of the coupling element 6 a recess in the form of an opening 800. This enables an engagement of the locking element 10 in the coupling element 6. The locking element 10 consequently protrudes in the locked state, as illustrated in FIGS. 5 and 6, through the opening 900 of the lower cover 9 and through the opening 800 of the lower cover 8. The locking element 10 is produced in this illustration as a locking pin with a truncated-pyramid-like or frustoconical geometry and engages in the positive-locking element 7, whereby the coupling element 6 is locked and the outer shaft 4 can no longer be rotated. The steering wheel is accordingly locked, but the inner shaft 5 can be rotated further, which further enables transmission of a now automatically generated steering command via the servo unit to the wheels. The engagement of the locking element 10 in the positive-locking element 7 and consequently the locking of the steering wheel take place prior to the uncoupling of the inner and outer shaft 5, 4, whereby the azimuthal position of the locked components, in particular the steering wheel, can be fixed in a position which, with manual steering, corresponds to a straight-ahead position of the wheels.
[0056] FIG. 6 shows a cut-out from FIG. 5 with a locked locking and coupling element 10, 6. As a result of the pretensioning of the spring 12 and the pressing thereof against a counter-face 13 which is arranged on the upper cover 8 in the second non-stored position, a resilient force component acts in a radially inward direction, that is to say, acting in the direction toward the steering shaft or inner shaft 5. The upper cover 8 has at the end face a first control face 801, wherein it is the end face which is received in the lower cover 9. When the upper cover 8 is inserted into the lower cover 9, the recess 800 is moved to the axial height of the locking element 10. The pretensioned spring 12 is consequently able to relax as a result of a radial movement of the locking element 10 which is directed in an orthogonal direction of the rotation axis 27 into the recess 800 of the upper cover 8. The radially inwardly directed movement of the locking element 10 leads to the locking element 10 being brought into engagement with the positive-locking element 7 which in the embodiment shown is constructed as a groove 37. As a result, the locking element 10 is retained in the locked position even when a torque acts on the coupling element 6, the coupling element 6 can no longer be rotated and consequently the outer shaft also cannot be rotated. The oblique construction of the control face 37 formed by the covering face of the locking element 10 relative to a surface 36 of the coupling element 6 facilitates a release of the locking when the upper cover 8 is moved into the second, extended position. A counter-control face 38 of the upper cover 8, against which face 38 the locking element 10 presses when the upper cover 8 is extended, is not parallel with the contacted control face 37 of the locking element 10. An advantageous embodiment is shown in which the control face 37 and counter-control face 38 are arranged relative to each other at an obtuse angle α, in particular at an angle α between 10° and 75°. Consequently, a force can be readily directed radially outward, which brings about a lifting of the locking element 10 via the application of the pretensioning/tensioning of the spring 12, whereby the locking element 10 and positive-locking element 7 can be brought out of engagement again. When the upper cover 8 is inserted into the lower cover 9, a second control face 37a of the locking element 10 cooperates with the control face 801 of the upper cover 8 so that, when the upper cover 8 is inserted, the locking element 10 is pressed with the second control face 37a against the control face 801 of the cover 8 and consequently the locking element 10 to be moved in a direction orthogonal relative to the rotation axis 27. The control face 37a and the control face 801 of the cover 8 are arranged at an angle relative to each other, wherein the angle preferably has a value between 10° and 75°.
[0057] FIG. 7 shows the steering shaft 26 in a partially exploded illustration, wherein it has the inner shaft 5 and outer shaft 4 with the coupling element 6 which is constructed as a latching star-like member. In the embodiment shown, the coupling of the inner and outer shaft 5, 4 during manual operation, and the uncoupling thereof when the inner shaft is coupled to the sleeve 15 is clear. The two portions 31, 32 of the outer shaft 4 each have different profiles and inner radii, in this instance the second portion 32 is constructed in the form of a circular pipe and the first portion 31 in the form of a polygonal shaft. The inner shaft 5 is also constructed as a polygonal shaft. In a state radially surrounding the inner shaft 5, there are further arranged two profile sleeves 14 whose outer cover forms the polygonal shape of the inner shaft 5. However, there may also be provision for only a single profile sleeve which is fixed to the inner shaft to be used. The profile sleeve or profile sleeves is/are preferably formed from a plastics material. During manual operation, the axial end 34 of the inner shaft 5 is located in the first portion 31 of the outer shaft 4. The regions in which the inner shaft 5 is surrounded by the profile sleeves 14 accordingly have peripheries which are increased in accordance with a width of the profile sleeves 14. Since an outer radius of the profile sleeve 14 is greater than an inner radius of the first portion 31 of the outer shaft 4, the inner shaft 5 cannot be rotated with the profile sleeves 14 counter to the outer shaft 4. Both are coupled in a rotationally secure manner, which is a prerequisite for the manual operation of the steering column. The sleeve 15 is supported inside the second portion 32 of the outer shaft 4. The sleeve 15 has an inner sleeve profile 33 which corresponds to an inner profile of the first portion 31 of the outer shaft 4. When the steering wheel is stored, the inner shaft 5 is inserted more deeply into the outer shaft 4 and the axial end 34 is arranged in the second portion 32 of the outer shaft 4—the inner shaft 5 is introduced into the sleeve 15. The profile sleeves 14 now form a positive-locking connection to the inner sleeve profile 33 and the inner shaft 5 and sleeve 15 are connected in a rotationally secure manner. Since the sleeve 15 is only supported in the outer shaft 4 in a sliding manner, the sleeve can be rotated when the inner shaft 5 is rotated relative to the outer shaft 4 and the rotation of the inner shaft and outer shaft 5, 4 is uncoupled. In other words, the sleeve 15 is supported in a sliding manner in the outer shaft. As a result of the now profile-sleeve-free portion of the inner shaft 5 inside the first portion 31 of the outer shaft 4, there is no longer a positive-locking connection between them and a relative rotation is enabled. In the preferred embodiment illustrated, the coupling element 6 radially surrounds the outer shaft 4 and is connected thereto in a rotationally secure manner. Furthermore, the rectangular groove 35 of the positive-locking element 7 extends over an axial length of the coupling element 6. This enables a deeper introduction of the inner shaft 5 into the outer shaft 4 in the already locked state of the locking element 10 and coupling element 6. An uncoupling of the inner and outer shaft 5, 4 which takes place only after the locking is thereby enabled. The outer shaft 4 illustrated in FIG. 7 is the outer shaft 4 after the first portion 31 has been formed with the positive-locking profile in the outer shaft 4, wherein, purely for ease of illustration, the sleeve 15 is illustrated outside the outer shaft 4. The sleeve 15 is joined before the forming of the positive-locking profile of the portion 31 in the outer shaft.
