Steering columns for motor vehicles

Abstract

The invention relates to a steering column (1) for a motor vehicle, comprising a housing unit (3) in which a steering spindle (4) is mounted so as to be rotatable about a longitudinal axis (L) extending in the longitudinal direction, wherein the housing unit (3) has at least three telescopic elements (31, 32, 33, 34, 35) which are adjustable relative to one another in the longitudinal direction and are guided in a telescopic manner. In order to provide a steering column (1) with increased strength and at the same time improved uniform adjustment behavior, the invention proposes that a positioning device (7) for the synchronous relative movement has a synchronous rotor (71) which is mounted so as to be rotatable about a rotor axis (S) transverse to the longitudinal axis and can roll with its outer circumference in the longitudinal direction on at least one telescopic element (31, 32, 33, 34, 35).

Description

Technical Field

[0001] The present invention relates to a steering column. Background Art

[0002] A steering column for a motor vehicle comprises a housing unit in which a steering spindle is rotatably mounted about its longitudinal axis in a steering spindle bearing unit. A steering wheel is attached to the end of the steering spindle that is located rearward in the direction of travel and faces the driver, for initiating steering commands by the driver. The housing unit is held by a supporting unit that is fixed to the vehicle body. By adjusting the housing unit relative to the supporting unit, the position of the steering wheel can be adjusted relative to the vehicle body.

[0003] With this type of steering column, the steering wheel can be adjusted longitudinally, i.e., in the direction of the longitudinal axis, rearward or forward relative to the driver's position, by means of the telescopically adjustable design of the housing unit and the steering spindle. Furthermore, the steering column can be pushed together longitudinally in the event of a collision, thereby effectively preventing it from entering the passenger compartment and causing injury to the passengers.

[0004] The housing unit of this type of steering column has at least three telescopic elements that can be extended or retracted relative to one another and are often referred to as housing elements or profile elements. This can be, for example, a triple or multiple telescopic assembly, which has at least three or more telescopic elements nested within one another and formed as a sleeve. This comprises at least one inner sleeve, also called an inner sleeve or inner sleeve, which is coaxially inserted into at least one central sleeve or intermediate sleeve, which itself is telescopically inserted into an outer sleeve (also called an outer sleeve or sleeve). By pushing the sleeves together or pulling them apart in the longitudinal direction, the housing unit, and therefore the steering column, can be shortened or lengthened.

[0005] The sleeves can be guided directly against one another, with only the housing element serving as the telescopic element. Also known are configurations of housing units with one or more intermediate elements positioned between the sleeves, which can be extended or retracted relative to the sleeves. Here, a sliding or rolling bearing unit can be coaxially arranged between two adjacent sleeves as a telescopic element. For example, such a rolling bearing unit, described in DE 10 2017 221 004 A1, comprises a rolling element cage coaxially arranged with the sleeves, in which rolling elements, such as balls or rollers, are mounted, which can roll between the sleeves. This forms a linear rolling bearing that enables smooth adjustment and low-play, flexure-resistant support. Alternatively, a linear sliding unit can be provided, for example, as a sliding bushing coaxially attached between the sleeves. Such a rolling bearing unit or sliding unit, which can be arranged between the outer sleeve, inner sleeve, and / or intermediate sleeve, is also telescopic relative to at least one sleeve and can thus form this type of telescopic element, i.e., an intermediate element of an intermediate support.

[0006] For longitudinal adjustment, the adjusting force is typically applied longitudinally between the outer and inner telescopic elements, that is, between the outer and inner sleeves. In autonomous driving, this is preferably applied via an electric adjusting drive. One or more telescopic elements, such as intermediate sleeves, rolling bearing units, or sliding units, mounted intermediately between the outer and inner telescopic elements are moved solely by longitudinal friction during sleeve adjustment. This can lead to undefined slippage, and especially after repeated adjustments, the intermediately mounted telescopic elements can drift axially to different positions relative to the sleeves during the same adjustment of the steering column. This uncontrolled drift has the disadvantage that the housing unit can have different stiffnesses in the same longitudinal arrangement depending on the relative position of the intermediately mounted telescopic elements. Furthermore, the required adjusting force can fluctuate disadvantageously due to uncontrolled longitudinal stops of the intermediate elements.

[0007] In view of the above problems, an object of the present invention is to provide a steering column having a high rigidity and at the same time an improved and more uniform adjustment behavior. Summary of the Invention

[0008] According to the invention, this object is achieved by the steering column according to the invention.

[0009] A steering column for a motor vehicle comprises a housing unit in which a steering spindle is supported so as to be rotatable about a longitudinal axis extending in the longitudinal direction, wherein the housing unit has at least three telescopically guided telescopic elements which can be adjusted relative to one another in the longitudinal direction. According to the invention, in the steering column, a positioning device for synchronous relative movement is provided with a synchronous rotor which is supported so as to be rotatable about a rotor axis which is transverse to the longitudinal axis and which can roll with its outer circumference in the longitudinal direction on at least one telescopic element.

[0010] The positioning device according to the invention allows for positive positioning of the three telescopic elements and synchronizes their relative longitudinal movement, so that the telescopic elements remain in a predefined relative position even after multiple adjustment cycles. Undefined drift of one telescopic element relative to the other two, as in the prior art, is avoided. The solution according to the invention thus increases the rigidity of the steering column and improves the adjustment behavior.

[0011] In an advantageous development, the telescopic elements of the housing units are guided in one another.

[0012] In an advantageous development, the synchronous rotor comprises at least a first synchronous gear and a second synchronous gear, which are connected to one another in a rotationally fixed manner, wherein the first synchronous gear has a first pitch circle diameter and can roll on the first telescopic element, and the second synchronous gear has a second pitch circle diameter and can roll on the second telescopic element, wherein the first pitch circle diameter is different from the second pitch circle diameter.

[0013] Therefore, a synchronous gear arrangement is provided having at least two or more synchronous gears connected to each other in a rotationally fixed manner, the synchronous gears having different pitch diameters. For example, two, three or more synchronous gears can be mounted on a common rotor shaft or synchronous shaft.

[0014] Due to the different diameters of the pitch circles (pitch diameters) of at least two synchronized wheels, different rolling distances are covered in the longitudinal direction when rolling through a specific rolling angle. The rolling distance of a synchronized wheel refers to the longitudinal distance that the rotor axis moves longitudinally relative to the telescopic element for a given rolling angle, and the synchronized wheel rolls on the telescopic element with its outer circumference. The diameter of the outer circumference effective during rolling is defined as the pitch diameter. For a given rolling angle α, the rolling distance l is obtained by multiplying it with the pitch diameter d as follows: l = d * α. Thus, the present invention advantageously allows the ratio of different relative adjustment distances of the telescopic elements, corresponding to the relative rolling distances of the telescopic elements synchronized with each other via the synchronized rotor, to be easily predetermined by the ratio of the pitch diameters of the synchronized wheels. Advantageously, this ratio can be freely selected to, for example, enable relative positioning between coaxially adjacent telescopic elements that differs from a fixed, centered positioning.

[0015] Another special advantage of this improved solution is that the relative longitudinal motion of three or more telescopic elements can be synchronized with each other simply and with little structural effort by the synchronous rotor. Each of the synchronous wheels can roll on one telescopic element respectively, or can also roll on two telescopic elements, for example, on the outside of an inner telescopic element and on the inside of an outer telescopic element. Another telescopic element can have a synchronous carrier or be constructed as such a synchronous carrier, in which the synchronous rotor is supported in a manner rotatable around a synchronous axis, so that the synchronous axis can move linearly with the telescopic element during adjustment. Therefore, by having a unique synchronous rotor according to the present invention with two synchronous wheels, five telescopic elements can be synchronized with each other, having a unique synchronous rotor according to the present invention with three synchronous wheels can synchronize seven telescopic elements with each other, and generally having a unique synchronous rotor according to the present invention with n synchronous wheels can synchronize a telescopic assembly with (2*n+1) telescopic elements with each other. Thus, it is possible to realize controlled, synchronous adjustment of multiple telescopic parts using additional rolling element units or sliding units without any problem, wherein only one synchronous rotor is required, or a small amount of synchronous rotors are required. As a result, the manufacturing and assembly outlay can be reduced, and the weight and size of the adjustable steering column can also advantageously be reduced.

[0016] It can be provided that two or more synchronization wheels each roll on one telescopic element, or that all or only a portion of a synchronization wheel each rolls on two telescopic elements. In this way, a greater number of telescopic elements can be positively coupled and synchronized with one another with less structural and design effort than with a single synchronization wheel in the prior art.

[0017] An advantageous embodiment provides that at least one of the synchronous wheels is designed as a gear. The gear can, for example, be designed as a spur gear with an externally circumferential toothing and mesh with at least one corresponding toothed rack extending longitudinally in the telescopic element. The gear can mesh simultaneously with two toothed racks, which can, for example, be mounted or constructed externally on the inner telescopic element and mounted or constructed internally on the outer telescopic element. The intermeshing toothing produces a positive engagement, so that the gear can roll on the toothed rack and thus on the corresponding telescopic element practically without slipping. The pitch circle diameter, which is important for determining the rolling path, can be predetermined in a manner known per se by means of the gear diameter, the module and the toothing geometry, for example, an involute toothing. The use of gears has the advantage that a precise, slip-free and loadable positive coupling can be achieved, thereby enabling synchronization with high functional and operational reliability.

[0018] Manufacturing and assembly costs can also be advantageously kept low. For example, the toothed rack can be integrally formed into the telescopic element, for example, also in one piece by plastic forming or machining, thereby achieving a lightweight and compact design. It is also conceivable and feasible to provide the toothed rack separately and subsequently assemble it on the telescopic element. For example, the toothed rack can be designed as an injection-molded part, for example, made of thermoplastic. The toothed rack can then be connected to the telescopic element, for example, by means of a clip connection, wherein the toothed rack's latching tongues engage corresponding recesses in the telescopic element.

[0019] It is possible that at least one synchronous wheel is configured as a friction wheel. The friction wheel can roll with its outer circumference on a linear raceway on the corresponding telescopic element in a friction-fitting, i.e., force-fitting manner. The outer diameter of the friction wheel is the same as the pitch diameter. To prevent slippage, the friction wheel can be designed to increase friction completely or partially at least on its rollable outer circumference. Additionally or alternatively, the telescopic element can be designed to increase friction completely or partially in the area of the raceway on which the friction wheel can roll with its outer circumference. The friction-increasing design can be achieved, for example, by surface roughening, such as embossing, knurling, or the like, and additionally or alternatively, by a friction-increasing coating, such as a rubber coating or the like. Such a friction wheel can be provided with low manufacturing and assembly effort, and the corresponding raceway can also be simply produced by a longitudinally extending surface, path, track, or the like.

[0020] It can be provided that the synchronous rotor is rotatably mounted on a synchronous carrier, which is formed by telescopic elements. Here, the synchronous rotor is rotatably mounted on one of the telescopic elements, and the synchronous wheel can roll on two or more other telescopic elements. As a result, the relative movement of the telescopic element forming the synchronous carrier is positively coupled and synchronized with the other telescopic elements.

[0021] Alternatively, the synchronous rotor can be rotatably mounted on a synchronous carrier, which is arranged to be movable relative to the telescopic elements. The synchronous carrier can, for example, include a bearing unit that is freely movable in the longitudinal direction relative to the telescopic elements and can preferably be guided in the possible directions of movement. In this design, the positive coupling is achieved solely by the rolling motion of the synchronous wheels on the relevant telescopic elements, so that if each individual synchronous wheel rolls on two telescopic elements, (2*n) telescopic elements can be synchronized with each other using n synchronous wheels.

[0022] If the synchronous wheels interact with the telescopic element only via their rollable outer circumference, the synchronous carrier can be designed separately from the telescopic element. In this embodiment, no synchronous wheels are rotatably mounted on the telescopic element. In other words, the common synchronous axis of the synchronous wheels of the synchronous rotor can be moved in the longitudinal direction relative to the telescopic element. The advantage of this independent synchronous carrier is that the telescopic element can be freely adjusted to any desired movement ratio simply by adjusting the pitch diameters of the synchronous wheels.

[0023] It can be provided that the synchronization axis is arranged tangentially between two telescopic elements. The synchronization wheel can thus roll on the radial inside or outside of the telescopic element. The synchronization axis can be arranged parallel to a tangent to the outer circumference of the essentially tubular telescopic element. The synchronization wheel can then roll on one or two coaxially adjacent telescopic elements. The rack or raceway corresponding to the synchronization wheel extends longitudinally parallel to the tangent plane. It is also possible that the synchronization wheel of the synchronous rotor is arranged only so as to be rollable between two coaxially adjacent telescopic elements, that is, no telescopic element is provided to rotatably support the synchronous rotor. Another synchronization wheel of the synchronous rotor can extend through a radial opening or recess in one or more adjacent telescopic elements and can roll on another coaxially located telescopic element further outside or inside.

[0024] It is also possible for the synchronization axis to extend substantially radially through at least three telescopic elements. The synchronization wheels are preferably arranged so that they can roll longitudinally on racks or raceways disposed or formed in radial through-holes of the corresponding telescopic elements. This arrangement has the advantage that all synchronization wheels that rollably interact with multiple, preferably all, telescopic elements can be mounted together in a torque-proof manner on the synchronization shaft. This allows a simple design with one or a small number of synchronization rotors, even in a housing unit with multiple telescopic elements.

[0025] The telescopic element can include at least one sleeve, which can be an outer sleeve, an inner sleeve, or an intermediate sleeve of the housing unit. The telescopic element can also include a rolling bearing or a sliding element arranged between the two sleeves. In all embodiments, the synchronous rotor can be supported on the sleeves or on the rolling bearing or sliding element arranged between them, or can roll freely thereon, i.e., it is not rotatably supported in the telescopic element, but can roll between coaxially adjacent telescopic elements.

[0026] The telescopic elements—the sleeves or the intermediate elements coaxially arranged therebetween, such as rolling bearings or sliding elements—are preferably tubular in design, with a circular or non-circular cross-section. The non-circular cross-section can be, for example, triangular, quadrilateral, hexagonal, octagonal, or polygonal. With such a polygonal profile, the synchronous rotor according to the present invention can preferably be arranged in the region of a flat, essentially planar side wall. The gear rack can also be arranged there or integrated into the sleeve wall. Alternatively, the side wall can include a raceway for the synchronous wheel. Even when the telescopic elements are designed with a non-circular cross-section, they are not intended for torque transmission. However, the telescopic elements are essentially different from the steering shaft, which transmits the steering torque input by the driver. Therefore, the telescopic elements do not form the steering shaft or steering axle that transmits torque, but rather rotatably accommodate or support the steering shaft within them.

[0027] Advantageously, the housing unit comprises a steering spindle bearing unit. The steering spindle bearing unit comprises one or more bearings in which the steering spindle is rotatably supported relative to one or more sleeves. Preferably, such bearings, which may include rolling bearings and sliding bearings, are arranged in at least one inner sleeve and / or outer sleeve.

[0028] The steering spindle is preferably designed to be adjustable in length, for example by means of a steering spindle section which is telescopic in the longitudinal direction.

[0029] To adjust the steering column, a motorized adjustment drive can be provided that engages two of the telescopic elements in order to adjust the sleeves relative to each other at least in the longitudinal direction. For example, the adjustment drive can act on the coaxially outer outer sleeve and the coaxially inner inner sleeve of the housing unit to pull them apart or push them together for longitudinal adjustment. The relative movement of the telescopic elements, coaxially arranged telescopically between the inner and outer housings, can be synchronized by the synchronous rotor according to the present invention. It is also conceivable and feasible for the adjustment drive to act on any two synchronously coupled telescopic elements, thereby also enabling adjustment of all synchronously coupled telescopic elements.

[0030] The adjustment drive can include a screw drive having a screw nut arranged on the screw and a drive motor, by which the screw and the screw nut can be driven in rotation relative to each other. Such adjustment drives are in principle known in the prior art and are considered to be reliable and durable. In this case, the screw nut is attached to a telescopic element, such as a sleeve, such as an inner sleeve or an outer sleeve, in a non-displaceable manner in the direction of the longitudinal axis, and the screw is attached to another sleeve, such as an outer sleeve or an inner sleeve, which can be telescoped relative to it. The screw nut or the screw is driven in rotation by an electric drive motor via a suitable transmission device, such as a worm drive or a belt drive, whereby the screw or the screw nut, which is fixed in rotation relative to it, moves in a translational manner in the direction of the longitudinal axis of the mandrel and, depending on the relative direction of rotation, the telescopic element is closed or separated in the longitudinal direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic perspective view of a steering column according to the invention is shown,

[0032] Figure 2 Shown through the Figure 1 A longitudinal section of the steering column,

[0033] Figure 3 Shown through the Figure 2 Cross section AA of the steering column,

[0034] Figure 4 Shown Figure 3 The enlarged part,

[0035] Figure 5 shows a cross section through a steering column in a second embodiment,

[0036] Figure 6 Shown Figure 5 The enlarged part,

[0037] Figure 7 shows a cross section through a steering column in a third embodiment,

[0038] Figure 8 A fourth embodiment of a steering column according to the invention is shown in a schematic perspective view.

[0039] Figure 9 Shown Figure 8 A magnified detail of

[0040] Figure 10 Shown according to Figure 8 A schematic perspective view of a partially disassembled steering column,

[0041] Figure 11 Shown according to Figure 8A separate detail view of the synchronous rotor according to the invention of a steering column,

[0042] Figure 12 Shown according to Figure 8 Cross section of a steering column. DETAILED DESCRIPTION

[0043] In the various figures, identical components are always provided with the same reference symbols and are therefore generally also each named or mentioned only once.

[0044] Figure 1 The steering column 1 according to the present invention is shown in a view obliquely from the rear, relative to the direction of travel, and includes an adjustment unit 2. The adjustment unit 2 comprises a housing unit 3 having an outer sleeve 31, a central or intermediate sleeve 32, and an inner sleeve 33, collectively referred to as sleeves 31, 32, and 33. The outer sleeve 31, the intermediate sleeve 32, and the inner sleeve 33 form a telescopic element within the meaning of the present invention. As indicated by the double arrow, these components are coaxially nested and telescopically movable in the longitudinal direction, which corresponds to the direction of the longitudinal axis L. The intermediate sleeve 32 constitutes an intermediate element within the meaning of the present invention.

[0045] A telescopic bearing unit 34 is coaxially arranged between the sleeves 31 and 32, which can be configured as a rolling bearing unit or a sliding bushing. A telescopic bearing unit 35 is coaxially arranged between the sleeves 32 and 33, which can be configured as a rolling bearing unit or a sliding bushing. The bearing unit 34 or 35 configured as a rolling bearing unit can include a tubular profile rolling bearing cage, which, as in Figure 3 and Figure 4 As can be seen in the sectional view of FIG, the rolling element can be coaxially arranged between the sleeves 32 and 33 and can roll longitudinally on the sleeves 32 and 33. The rolling element can be rotatably supported in the rolling bearing cage. Alternatively, a tube-shaped sliding bushing can also be provided without rolling elements.

[0046] The sleeves 31 , 32 , 33 and the support units 34 , 35 are telescopically nested in one another and form telescopic elements within the meaning of the present invention. In the example shown, the telescopic elements 31 , 32 , 33 , 34 , 35 are designed as octagonal tube segments.

[0047] The steering spindle 4 is mounted in the housing unit 3 so as to be rotatable about the longitudinal axis L. At its rear end, it has a connecting section 41 for attaching a steering wheel (not shown). The steering spindle 4 is mounted in the sleeve 33 in a steering spindle bearing unit 42, which can preferably include a rolling bearing. Another similarly designed steering spindle bearing unit, not visible here, can preferably be arranged in the outer sleeve 31.

[0048] The housing unit 3 is held in a two-part carrying unit 5 , which has a fastening means 51 in the form of an opening for mounting on a vehicle body (not shown).

[0049] The adjustment drive 6 includes a spindle drive with a spindle nut 61 and a spindle 62 screwed therein, which can be driven to rotate relative to one another by an electric motor 63. The spindle 62 extends parallel to the longitudinal axis L and is connected to the inner sleeve 33. The spindle nut 61 is supported longitudinally on the outer sleeve 31 by the adjustment drive 6. By rotating the spindle 62 and spindle nut 61 relative to each other by the motor 63, the spindle 62 and spindle nut 61 move toward or away from each other, depending on the direction of rotation. This allows the inner sleeve 33 to be longitudinally moved into or out of the outer sleeve 31, as indicated by the double arrow. This enables longitudinal adjustment, allowing the steering wheel, which is mounted on the connecting section 41, to be moved forward into a stored position, in which the inner sleeve 33 and the intermediate sleeve 32 are moved into the outer sleeve 31 (i.e., retracted forward), or into an operating position in the operating area, in which the sleeves 31, 32, and 33 are moved away from one another.

[0050] Alternatively, the spindle nut 61 may be supported on the inner sleeve 33 , and the screw 62 may be supported on the outer sleeve 31 .

[0051] exist Figure 1 , the adjustment position of the steering column 1 is shown in an operating state, in which the intermediate sleeve 32 and the inner sleeve 33 are at least partially moved out of the outer sleeve 31 in the longitudinal direction relative to the direction of travel of the motor vehicle to the rear - to the right in the drawing - so that the steering wheel attached to the connecting section 41 is located in the operating area for inputting steering commands.

[0052] exist Figure 2 , the housing unit 3 is shown in a longitudinal section along the longitudinal axis L. The coaxial telescopic arrangement of telescopic elements 31 , 32 , 33 , 34 , 35 , which comprises sleeves 31 , 32 , 33 and bearing units 34 , 35 , can be seen therein.

[0053] The steering spindle 4 is also designed to be adjustable in the longitudinal direction and, for this purpose, has an inner shaft 43, which is telescopically inserted into an outer shaft 44. Due to the non-circular contour, the connection is designed to be torque-locking in a manner known per se.

[0054] The positioning device 7 according to the present invention has a synchronous rotor 71 which is supported in the sleeve 32 (intermediate sleeve) in a manner such that it can rotate about the synchronous axis S. Figure 4 Can be seen in.

[0055] The synchronous rotor 71 has a first synchronous gear 72 , which has a first pitch circle diameter d1 and is connected in a rotationally fixed manner to a second synchronous gear 73 , which in this example has a smaller pitch circle diameter d2 .

[0056] The outer periphery of the synchronous wheel 72 rolls on a raceway 310 formed inside the sleeve 31 (outer sleeve) and on a raceway 330 formed outside the sleeve 33 (inner sleeve). The outer periphery of the synchronous wheel 73 rolls on a raceway 340 formed inside the bearing unit 34, such as a rolling bearing cage, and on a raceway 350 formed outside the bearing unit 35.

[0057] The synchronization wheels 72 and 73 can be designed as gears with spur teeth running around the outside, which mesh with raceways 310, 330, 340, 350 designed as corresponding racks. As a result, the synchronization wheels 72, 73 roll in the longitudinal direction on the telescopic elements 31, 33, 34, 35 without slipping during adjustment.

[0058] The telescopic elements 31, 32, 33, 34, 35 are positively coupled with respect to their relative movement in the longitudinal direction by means of the synchronous rotor 71 and are thus synchronized. Figure 4 When pulled toward the observer, or when Figure 2 When the sleeve 32 is pulled out toward the right, the synchronous wheel 72 rolls between them and moves the sleeve 32 halfway through its adjustment stroke, w / 2, so that the sleeve 32 is always centered between the sleeves 31 and 33. The synchronous wheel 73 moves the support unit 35 relative to the sleeve 32 in the direction of the sleeve 33, but the stroke is less than that of the sleeve 33 by a fraction d2 / d1 of the ratio of the pitch diameter. For example, if d2 / d1 is 0.5, the support unit is moved halfway and is always centered between the sleeves 33 and 32. Similarly, the support unit 34, which is also meshed with the synchronous wheel 73, moves in the opposite direction, so that it is always centered between the sleeves 31 and 32.

[0059] In this way, all telescopic elements 31 , 32 , 33 , 34 , 35 can be synchronized by means of a single synchronous rotor 71 according to the invention.

[0060] exist Figure 5 China and Israel Figure 3 The embodiment shown in the same figure in Figure 6 Zhong Ruzai Figure 4 The characteristic feature of the synchronous rotor 71 is that it has a total of four synchronous wheels 72, 73, 74, 75 which are connected to each other in a rotationally fixed manner.

[0061] The synchronous rotor 71 is supported on the sleeve 32 (intermediate sleeve) so as to be rotatable about the synchronous axis S.

[0062] The synchronous wheel 72 has a pitch circle diameter d1 and rolls only on the sleeve 33 (inner sleeve), on the raceway 330 .

[0063] The synchronization wheel 73 has a pitch circle diameter d2 and rolls exclusively on the bearing unit 35 arranged between the sleeves 32 and 33 , for example on the rolling element cage of the rolling element unit, on the raceway 350 .

[0064] The synchronous wheel 74 has a pitch circle diameter d3 and rolls only on the sleeve 31 (outer sleeve), on the raceway 310 .

[0065] The synchronous gear 75 has a pitch circle diameter d4 and rolls exclusively on the bearing unit 34 arranged between the sleeves 32 and 31 , for example on a rolling element cage, on the raceway 340 .

[0066] By means of the ratio d1 : d2 : d3 : d4 of the pitch circle diameters, which can all be different as in the example shown, the ratio of the relative movements of the telescopic elements 31 , 32 , 33 , 34 , 35 can be predefined in a positively coupled manner during adjustment and thus synchronized.

[0067] The synchronization wheels 72 , 73 , 74 , 75 can also be designed as friction wheels, which roll with their outer circumference in a friction-locking manner on the telescopic elements 31 , 33 , 34 , 35 in the longitudinal direction.

[0068] The synchronous wheels 72, 73, 74, 75 can be coupled in a rotationally fixed manner on a common shaft. It is also conceivable and feasible that all synchronous wheels 72, 73, 74, 75 are formed in one piece, for example as plastic injection moldings or as metal castings.

[0069] Figure 7 As Figure 4 or Figure 5 The cross-sectional view of FIG. 1 shows an improved solution, in which the synchronous rotor 71 can be connected to, for example, Figure 4 or Figure 6The embodiment described in [ 1 ] is constructed identically. In this embodiment, the raceway on which the synchronous rotor 71 and the synchronous wheel 72 roll on the sleeve 33 (inner sleeve) is configured as the crash element 8. This crash element 8 can include, for example, a gear rack connected to the sleeve 33 via an energy absorber, or the gear rack itself can be designed as part of the energy absorber. For example, the crash element 8 can include an element or material that, in the event of a crash, when a large force peak is applied longitudinally to the housing unit 3 by a person or object striking the steering column 1, plastically deforms during the relative longitudinal movement of the synchronous rotor 71 relative to the telescopic elements 31, 32, 33, 34, 35, thereby absorbing the kinetic energy of the collision and converting it into deformation and heat. For example, the crash element 8 can include a toothed section made of a soft material that is plastically torn or compressed by the abrupt, unsynchronized sliding of the synchronous wheel 72 in the event of a crash.

[0070] One or more crash elements 8 can also be arranged or formed on other or additional telescopic elements 31, 32, 33, 34, 35. Energy absorption elements known per se can also be arranged between the crash element 8 and one or more telescopic elements 31, 32, 33, 34, 35, such as expansion elements, bending elements, compression elements and / or tearing elements that plastically deform during energy absorption when relative movements occur only in the longitudinal direction in the event of a crash.

[0071] Figure 8 Another possible embodiment of the steering column 1 is shown in an overall perspective view, and Figure 9 An enlarged view of a positioning device 7 according to the invention is shown in an alternative embodiment. The same reference numerals are used for components having the same effect.

[0072] An electric adjusting drive 60 , which can be designed similarly to the adjusting drive 6 , is arranged between the housing unit 3 and the carrying unit 5 and enables a height adjustment of the housing unit 3 in the height direction H.

[0073] The positioning device 7 has a synchronous rotor 71, which is Figure 11 The synchronous rotor has a total of four synchronous gears 72 , 73 , 74 , 75 which are connected to one another in a rotationally fixed manner and are mounted rotatably about their common synchronous axis S in a synchronous carrier 76 .

[0074] The synchronous rotor 71 extends with the synchronous axis S through the radial opening 36 through the telescopic elements 31, 32, 33, 34, 35. A raceway 310, 330, 340, 350 is provided on the longitudinal edges of the opening 36. In this embodiment, the raceway is designed as a toothed rack, the teeth of which are integrally formed in the telescopic elements 31, 32, 33, 34, 35 in the circumferential direction relative to the longitudinal axis L.

[0075] The synchronization carrier 76 is guided longitudinally in the opening 76, with the synchronization wheels 72, 73, 74, 75 engaging with the raceways 310, 330, 340, 350. This achieves a positive relative positioning of the telescopic elements 31, 32, 33, 34, 35 in the longitudinal direction, i.e., synchronization. The synchronization axis S moves along with the synchronization carrier 76, which is not fixedly connected to any of the telescopic elements 31, 32, 33, 34, 35 but is coupled thereto solely via the synchronization wheels 72, 73, 74, 75.

[0076] exist Figure 12 The radial arrangement of the synchronous rotor 71 , which passes radially through the telescopic elements 31 , 32 , 33 , 34 , 35 via openings 76 , can be clearly seen in the cross section of FIG.

[0077] Figure 10 A partially opened view of the housing unit 3 is shown, in which the radial arrangement of the synchronous rotor 71 in the opening 76 is illustrated. This figure also shows how the rolling bodies 37 are rotatably arranged in the bearing unit 35 designed as a rolling body unit, which can roll on the sleeves 32 and 33 during adjustment.

[0078] In an embodiment (not shown), provision can be made for a gear wheel and a friction wheel to be used in combination with one another as a synchronous wheel in a single embodiment.

[0079] Description of Reference Numerals

[0080] 1st steering column

[0081] 2 adjustment units

[0082] 3 Shell elements

[0083] 31 outer sleeve

[0084] 32 intermediate casing

[0085] 33 inner casing

[0086] 34, 35 support units

[0087] 36 openings

[0088] 37 rolling elements

[0089] 310, 330, 340, 350 raceways

[0090] 4 steering spindles

[0091] 41 connecting sections

[0092] 42 Steering shaft support unit

[0093] 43 inner shaft

[0094] 44 external shaft

[0095] 5 load-bearing units

[0096] 51 fixed mechanism

[0097] 6. 60 adjustable drive

[0098] 61 screw nut

[0099] 62 screw

[0100] 63 motor

[0101] 7 Positioning device

[0102] 71 Synchronous Rotor

[0103] 72, 73, 74, 75 synchronous wheels

[0104] 76 Synchronous Carrier

[0105] 8 collision elements

[0106] L longitudinal axis

[0107] H height direction

[0108] S Synchronous Axis

[0109] d1, d2, d3, d4 pitch circle diameters

Claims

1. A steering column (1) for a motor vehicle, comprising a housing unit (3) in which a steering spindle (4) is mounted so as to be rotatable about a longitudinal axis (L) extending in the longitudinal direction, wherein: The housing unit (3) has at least three telescopic elements which are adjustable relative to one another in the longitudinal direction and are guided in a telescopic manner. It is characterized by: A positioning device (7) for the relative movement of synchronous telescopic elements comprises a synchronous rotor (71) which is mounted rotatably about a synchronous axis (S) transverse to the longitudinal axis and can roll with its outer circumference in the longitudinal direction on at least one telescopic element; The synchronous rotor (71) has at least one first synchronous wheel (72) and a second synchronous wheel (73), which are connected to each other in a rotationally fixed manner, wherein the first synchronous wheel (72) has a first pitch circle diameter (d1) and can roll on a first telescopic element (33), and the second synchronous wheel (73) has a second pitch circle diameter (d2) and can roll on a second telescopic element (35), wherein the first pitch circle diameter (d1) is different from the second pitch circle diameter (d2).

2. Steering column (1) according to the preceding claim 1, characterized in that At least one synchronous gear is designed as a gear wheel.

3. Steering column (1) according to the preceding claim 1, characterized in that At least one synchronous gear is designed as a friction gear.

4. Steering column (1) according to any one of the preceding claims 1-3, characterized in that The synchronous rotor (71) is rotatably supported on a synchronous carrier, which is formed by a telescopic element.

5. Steering column (1) according to any one of the preceding claims 1-3, characterized in that The synchronous rotor (71) is rotatably mounted on a synchronous carrier (76), which is arranged so as to be movable relative to the telescopic element.

6. Steering column (1) according to any one of the preceding claims 1-3, characterized in that The common synchronization axis of the synchronization wheels of the synchronization rotor (71) can be moved in the longitudinal direction relative to the telescopic element.

7. Steering column (1) according to any one of the preceding claims 1-3, characterized in that The synchronization axis (S) is arranged tangentially between the two telescopic elements.

8. Steering column (1) according to any one of the preceding claims 1 to 3, characterized in that The synchronization axis (S) passes radially through the at least three telescopic elements.

9. Steering column (1) according to any one of the preceding claims 1-3, characterized in that The synchronous rotor (71) extends radially through at least one telescopic element.

10. Steering column (1) according to any one of the preceding claims 1-3, characterized in that The telescopic element includes a sleeve.

11. Steering column (1) according to any one of the preceding claims 1-3, characterized in that The telescopic element comprises a rolling bearing unit or a sliding unit which is arranged between two sleeves.

12. Steering column (1) according to any one of the preceding claims 1-3, characterized in that The housing unit (3) has a steering spindle bearing unit (42).

13. Steering column (1) according to any one of the preceding claims 1-3, characterized in that At least one synchronization wheel can roll on both telescopic elements.

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