Steering column for a motor vehicle

Abstract

The present invention relates to an adjustment actuator (6) for a power-adjustable steering column (1) of a motor vehicle, the adjustment actuator comprising an externally threaded spindle (62) having an external thread (620) engaging with a spindle nut (63) and an internal thread (621) engaging with an internally threaded spindle (61), wherein the spindle nut (63), the externally threaded spindle (62), and the internally threaded spindle (61) can be driven by a motor drive unit (64) to rotate relative to each other about an axis (G). To improve adjustment behavior, particularly tactile and acoustic adjustment behavior and to increase design freedom, the present invention proposes a blocking device (7) capable of switching between a first position and a second position. In the first position, the externally threaded spindle (62) is locked to the spindle nut (63) in a rotationally fixed manner, and in the second position, the externally threaded spindle (62) is locked to the internally threaded spindle (61) in a rotationally fixed manner.

Description

Technical Field

[0001] This invention relates to an adjustment actuator for a motor-adjustable steering column of a motor vehicle, the adjustment actuator comprising an externally threaded spindle having an external thread engaging with a spindle nut and an internal thread engaging with an internally threaded spindle, wherein the spindle nut, the externally threaded spindle, and the internally threaded spindle can be driven by a motor-type drive unit to rotate relative to each other about an axis. The invention also relates to a steering column for a motor vehicle and a method for operating the adjustment actuator. Background Technology

[0002] The steering column for motor vehicles has a steering shaft with a steering spindle. A steering wheel is attached to the rear end of the steering shaft, viewed in the direction of travel and facing the driver, for inputting steering commands by the driver. The steering spindle is mounted so as to be rotatable about the longitudinal axis of the steering spindle within a housing tube of a positioning unit, which is held to the vehicle body by a support unit. Because the positioning unit has at least one housing tube that can be telescopically moved along the longitudinal axis within a housing unit, also known as a guide box or box arm, connected to the support unit, the steering wheel can be longitudinally adjusted relative to the vehicle body. Vertical adjustment can be achieved by either a positioning unit pivotally mounted on the support unit or by a housing unit that receives the positioning unit. Adjustment of the positioning unit in the longitudinal or vertical direction allows for the setting of an ergonomically comfortable steering wheel position relative to the driver's position in the operating position—also known as the driving control position or operational control position—where manual steering intervention is possible.

[0003] In the case of a motor-adjustable steering column, a motor-type adjustment actuator is known for use in adjustment purposes. This actuator has a drive unit including an electric drive motor that drives the spindle mechanism using a threaded spindle screwed into a spindle nut. The threaded spindle and spindle nut can be driven by the drive unit to rotate relative to each other about their common axis, the threaded spindle axis, or the spindle axis, thereby allowing the threaded spindle and spindle nut to move towards or away from each other in a translational manner along the direction of the threaded spindle axis, depending on the direction of rotation. Due to the fact that the threaded spindle and spindle nut are attached to components of the steering column that are adjustable relative to each other, such as a housing tube that is telescopically adjustable in the axial direction and attached to a housing unit, or attached to a housing unit and a support unit for support in the axial direction, longitudinal or vertical adjustment is possible.

[0004] In an embodiment known as a plunger spindle actuator, a threaded spindle is coupled to a stationary portion of the steering column in a non-rotatable manner relative to its axis of rotation. This portion is, for example, a support unit, housing unit, or housing tube fixed to the vehicle body housing. The spindle nut is supported such that it can be driven to rotate axially on a portion of the steering column that is adjustable relative to the spindle nut. Because the spindle nut is driven to rotate, translational movement relative to the threaded spindle is possible, thereby allowing these portions of the steering column connected via the spindle mechanism to be adjusted relative to each other. For example, a steering column with an adjustment actuator of this type is described in DE 10 2017 207 561 A1.

[0005] Alternatively, in an implementation known as a rotary spindle drive, the threaded spindle can be driven to rotate relative to the steering column, and the spindle nut can remain stationary relative to rotation about the spindle axis.

[0006] In the case of a simple rotary drive or spindle drive, the maximum achievable adjustment stroke is limited by the length of the threaded spindle. To enable greater adjustment, such as retracting the steering wheel beyond the range of manual operator control or comfort during autonomous driving operation, a correspondingly long threaded spindle is required. To overcome this limitation, DE10 2018 212 696 B3 proposes a general-purpose multi-stage adjustment drive with two spindle mechanisms arranged in a telescopic nested configuration. Here, the first threaded spindle, or external threaded spindle—hereinafter referred to as the external threaded spindle—is constructed as a hollow spindle with an internal thread coaxial with the external thread, and this internal thread is engaged by an internal threaded spindle supported on the steering column for common rotation. Thus, the first spindle mechanism is formed. The external threaded spindle engages via the external thread of the external threaded spindle with a spindle nut, also referred to as the drive nut, which can be driven to rotate by a drive motor, and this spindle nut is axially supported on the drive unit. Thus, the second spindle mechanism is formed.

[0007] When the drive unit is activated, the spindle nut rotates relative to two threaded spindles arranged in a multi-stage configuration. Due to the fact that only the internal threaded spindle has supports defined for co-rotation, different operating states may occur: the external threaded spindle rotates co-rotating with the spindle nut, where the first spindle mechanism is activated; or the external threaded spindle rotates co-rotating with the internal threaded spindle, activating the second spindle mechanism; or the external threaded spindle rotates partially co-rotating with both the external and internal threaded spindles simultaneously, activating both spindle mechanisms. Here, the actual operating state during adjustment depends on thread friction, which in turn depends on various parameters such as tolerances, temperature, and surface characteristics. A disadvantage of this is the lack of definition regarding which spindle mechanism is activated and when during adjustment. Therefore, adjustment behavior may be impaired tactilely and acoustically, particularly resulting in not every adjustment operation feeling and / or sounding the same, because during the first adjustment operation, one spindle mechanism is activated first, followed by the other, while in subsequent adjustment operations, the order is reversed. It has been found that vehicle drivers, especially those of luxury vehicles, find this unsettling, unpleasant, and of poor quality. Furthermore, design freedom is limited because the two spindle mechanisms must have identical transmission characteristics in converting relative rotation into axial motion.

[0008] In view of the problems discussed above, the object of the present invention is to improve the regulatory behavior, particularly the regulatory behavior in terms of tactile and acoustic aspects, and to increase design freedom. Summary of the Invention

[0009] According to the present invention, the objective is achieved by means of the adjusting drive, steering column, and corresponding method of the present invention.

[0010] In the case of an adjustment drive for a motor-adjustable steering column in a motor vehicle, the adjustment drive includes an externally threaded spindle having an external thread that engages with a spindle nut and an internal thread that engages with an internally threaded spindle. The spindle nut, the externally threaded spindle, and the internally threaded spindle can be driven by a motor-type drive unit to rotate relative to each other about an axis. According to the invention, a blocking device is provided that can switch between a first position and a second position, wherein in the first position, the externally threaded spindle is locked together with the spindle nut for joint rotation, and in the second position, the externally threaded spindle and the internally threaded spindle are locked together for joint rotation.

[0011] With the aid of the blocking device according to the invention, in the case of a multi-stage adjustment drive, the first position or the second position can be selectively employed in a defined manner, thereby clearly and uniquely defining the corresponding operating mode of the multi-stage spindle mechanism.

[0012] In the first position, also known as the outer stop position, corresponding to the first operating mode, the external thread spindle and spindle nut are locked together by means of a stop device to rotate together in both rotational directions, thereby achieving a common rotational connection acting in both rotational directions. This first position can be employed, for example, within the retracted adjustment range—referred to simply as the retracted range—which refers to the adjustment range between the retracted position of the steering column and the comfort or operator control range, and passes through this retracted range in the forward adjustment direction during retraction or conversely in the rearward adjustment direction during unfolding from the retracted position. In both possible rotational directions, and therefore in both possible adjustment directions, the common rotational lock remains as long as the first position is employed; that is, preferably, the common rotational lock remains maintained throughout the entire retracted range.

[0013] In this first position, the spindle nut is driven by a drive unit to rotate together with the externally threaded spindle connected to the spindle nut. In this way, the first spindle mechanism, formed solely by the externally threaded spindle and the internally threaded spindle, is activated.

[0014] If the blocking device switches from the first position to the second position, which can also be referred to as the inner blocking position, the common rotational connection between the spindle nut and the external thread spindle is released, and the internal thread spindle and the external thread spindle are locked together to rotate together in both rotational directions; that is, the internal thread spindle is connected to the external thread spindle so that the internal thread spindle cannot rotate relative to the external thread spindle. In this way, the first spindle mechanism is deactivated, and the second spindle mechanism formed by the spindle nut and the external thread spindle is activated. When the spindle nut is driven to rotate, the external thread spindle, together with the internal thread spindle fixed therein, moves linearly and axially in either the forward or backward adjustment direction, depending on the direction of rotation. Within the entire adjustment range covered by the second spindle mechanism, such as the comfort adjustment range for adapting the operator's control position to the steering wheel within the operator control range, the first spindle mechanism is blocked by the blocking device and is inactive.

[0015] In the case of multi-stage spindle mechanisms, for adjustment purposes, the present invention first allows controlled activation of only the first spindle mechanism or only the second spindle mechanism. This results in the absence of undefined mixed operating modes as in the prior art, leading to a significant improvement in tactile and acoustic characteristics in adjustment behavior compared to the prior art. This function is defined and independent of thread friction. Another major advantage stems from the fact that the transmission ratio, which defines the ratio between the rotational and axial linear movements of the two spindle mechanisms, can be specified independently of each other. This is possible because, in the operating modes defined by the first or second position, it is not possible to superimpose undefined movements as in the prior art. This allows for greater design freedom, and therefore, for example, for a given drive rotational speed, faster adjustment can be specified in the retraction range than in the comfort range via a larger thread pitch.

[0016] The external thread of the external thread spindle and the internal thread of the external thread spindle are preferably coaxial with respect to each other.

[0017] In an advantageous improvement, the blocking device can be configured to interact with the spindle nut, the external thread spindle, and the internal thread spindle to switch from a second position to a first position at a predetermined relative position according to the forward adjustment direction, and to switch from the first position to the second position in the opposite direction of the forward adjustment direction at a relative position according to the rearward adjustment direction. The predetermined relative position for switching is also called the switching position. In this embodiment, the switching of the blocking device can occur automatically in each case, whether when the steering column retracts from the comfort range to the retracted range in the forward adjustment direction or conversely when the steering column extends from the retracted range to the comfort range in the rearward adjustment direction, upon reaching the switching position or during adjustment through the switching position. Then, due to the relative movement of the spindle nut and the external thread spindle, and the relative movement of the external thread spindle and the internal thread spindle, the blocking device is actuated in each case. For actuation purposes, a suitable actuation device can be provided, which may have, for example, a mechanical form-fitting guide. These features can be designed and configured such that during adjustment within the comfort range or the retracted range, the blocking device remains in the associated first or second position in each case and cannot be switched. When reaching or exceeding the predetermined switching position of the threaded spindle at the transition between the comfort range and the retracted range along one adjustment direction or the opposite adjustment direction, switching to one or the other position can be controlled in a form-fitting manner. The advantage is that, in this way, one of the two spindle mechanisms is always assigned to an adjustment range in a defined manner, and thus a unique and defined activation sequence of the spindle mechanisms is established automatically.

[0018] For example, the blocking device can have a locking element capable of moving between a first position and a second position. This locking element can selectively move mechanically between the positions, and thus switch between them. In the first position, the locking element connects the externally threaded spindle to the spindle nut for common rotation, and in the second position, the locking element connects the externally threaded spindle to the internally threaded spindle for common rotation. The movable locking element can be implemented at low cost in a functionally reliable manner.

[0019] The locking element preferably has a control surface that interacts with a corresponding control surface, and the locking element forms a control mechanism similar in nature to a cam follower. One or more corresponding control surfaces may be provided. The corresponding control surfaces may preferably be located on an internally threaded spindle and / or a spindle nut. The control mechanism, similar in nature to a cam follower, moves the locking element from a first position to a second position, or from a second position to a first position.

[0020] An advantageous improvement could be that the locking element is movably mounted on an externally threaded spindle and can be selectively positioned to engage with a locking reception of either the spindle nut or the locking reception of an internally threaded spindle. Here, the locking element is mounted and axially supported on the externally threaded spindle. The locking element moves with the externally threaded spindle during relative movement and, in each case, can engage with one of the locking receptions at a relative position configured as a switching position for the purpose of creating an axial form fit. For example, in a first position, the locking element can protrude radially outward from the inside of the spindle nut to engage in a form fit with a locking reception referred to as the outer locking reception. To move to a second position, the locking element moves radially inward laterally relative to the axis to engage in a form fit with a locking reception located on the outside of the internally threaded spindle, referred to as the inner locking reception. The locking element can be formed in a simple and reliable manner as a mechanical blocking member of the type described above, wherein the form fit connection can be achieved mechanically simply and has a stable blocking effect. Another advantage is that the locking element can be accommodated in a space-saving and protected manner between the internally threaded spindle and the spindle nut.

[0021] For example, the locking receiving portion may have a recess formed in the spindle nut and / or the internally threaded spindle. This recess can be simply formed by a cut, opening, groove, etc., defined in the axial direction, and the locking element can be introduced radially into said cut, opening, groove, etc., to form a form-fit connection acting in the axial direction. This recess can be formed at low cost, for example, radially from the inside in the internal thread region of the spindle nut, or radially from the outside in the external thread region of the internally threaded spindle. The recess preferably has one or more corresponding control surfaces.

[0022] In an advantageous embodiment, the locking element can be arranged in the orifice of an externally threaded spindle. This orifice extends radially through the externally threaded spindle and forms an opening that passes radially between the internally threaded spindle and the spindle nut. The locking element is mounted in the orifice in an axially supported and radially movable manner. For example, the locking element can have a spherical member serving as the locking body, sized such that the spherical member protrudes radially inward or outward from the externally threaded spindle in each operating mode. Therefore, the locking element can only be in two operating positions, wherein in a first position, the locking element engages with the outer locking reception from the inside, and in a second position, the locking element engages with the inner locking reception from the outside. Due to the fact that the locking body has a relatively small size relative to the cross-section of the orifice, and for example, the spherical member has a relatively small diameter, the spherical member can easily move back and forth within the orifice for the purpose of switching between the first and second positions. The blocking device of this embodiment can be implemented in a very simple, reliable, and space-saving form.

[0023] To enable automatic switching of the blocking device during adjustment, the spindle nut can be configured to have a first actuation device that switches the locking element from a first position to a second position, and the internal thread spindle can have a second actuation device that switches the locking element from the second position to the first position. At a specified relative position during the axial relative movement of the spindle nut relative to the external thread spindle, i.e., the switching position, the first actuation device performs radial movement for switching the locking element, and at a specified relative position during the axial relative movement of the external thread spindle relative to the internal thread spindle, the second actuation device performs radial movement for switching the locking element in the opposite direction. For example, the actuation device may include a switching ramp inclined axially relative to the axis, and due to a wedge effect, the axial relative movement, by means of the switching ramp, causes radial movement for switching the locking element, for example, causing radial movement of a spherical element arranged in the bore of the external thread spindle.

[0024] The external threaded spindle may have a defining device that abuts against the spindle nut in the axial direction. The defining device may have an axial stop, such as a protrusion or an annular collar, that protrudes radially outward beyond the external thread and, as an end stop, abuts against the spindle nut axially when the maximum possible adjustment is achieved. Specifically, the stop position may coincide with the aforementioned relative position in which the blocking device is located in a second position, in which the internal threaded spindle and the external threaded spindle are locked together by means of a locking element in a form-fitting manner to rotate together in both rotational directions and be connected to each other.

[0025] This invention advantageously allows the external thread of an external threaded spindle and its internal thread to have different pitches. For example, the internal thread can be configured to have a larger pitch than the external thread. In this way, the first spindle mechanism has a relatively high transmission ratio, enabling rapid adjustment movements within a narrow range for a given actuator rotational speed, as described above. For this purpose, the internal threaded spindle can have, for example, a multi-turn steep lead angle thread. In contrast, the relatively smaller pitch of the external thread on the external threaded spindle allows for slower and more precise adjustments within a comfortable range. This significantly increases the design freedom to adapt the adjustment actuator to individual needs.

[0026] In an advantageous improvement, the spindle nut and / or externally threaded spindle and / or internally threaded spindle may be configured to contain or be formed of plastic.

[0027] Advantageously, at least one of the threads can have a self-locking design. For example, since the external thread of the external threaded spindle is self-locking within a comfortable range due to its relatively small thread pitch, it can be ensured that even high axial forces acting on the adjustment drive will not cause the steering wheel position to be adjusted.

[0028] The invention also includes a steering column for a motor vehicle, comprising an adjustment actuator having one or more of the features described above, and the adjustment actuator being arranged between housings or housing tubes of a housing unit, the housings or housing tubes being axially adjustable in a telescoping manner relative to each other and rotatably supporting the steering spindle, and / or the adjustment actuator being arranged between a support unit capable of connecting to a body shell of the motor vehicle and a housing unit rotatably receiving the steering spindle. Longitudinal adjustment in the longitudinal axis direction of the steering spindle can be achieved by means of the telescoping adjustment of the housing tube, and vertical adjustment can be achieved by means of the arrangement between the support unit and the housing unit. Longitudinal and vertical adjustments can be provided individually or in combination. The advantage of using the adjustment actuator according to the invention is that improved, defined adjustments can be achieved, for example, adjustments with different adjustment characteristics within a comfort range or operator control range and retractable range, and greater design freedom can be achieved during the design process.

[0029] The present invention also relates to a method according to the invention for operating an adjustment drive according to the above-described embodiment, the adjustment drive comprising an externally threaded spindle having an external thread engaging with a spindle nut and an internal thread engaging with an internally threaded spindle, wherein the spindle nut, the externally threaded spindle, and the internally threaded spindle can be driven by a motor-type drive unit to rotate relative to each other about an axis. In this method, according to the invention, in a first adjustment range, i.e., a so-called retraction range, the externally threaded spindle and the spindle nut are locked together for common rotation, and the externally threaded spindle is driven to rotate relative to the internally threaded spindle; and in a second adjustment range, i.e., a comfort adjustment range, the externally threaded spindle and the internally threaded spindle are locked together for common rotation, and the spindle nut is driven to rotate relative to the externally threaded spindle.

[0030] The above-described embodiments and method steps regarding the adjustment actuator and the steering column according to the invention can be applied individually or in combination to the method according to the invention. By means of selective locking of the main shaft nut and the external threaded main shaft, or selective locking of the external threaded main shaft and the internal threaded main shaft, better defined adjustment characteristics than those of the prior art can be achieved. Other advantages include greater design freedom and improved ease of operator control and user-friendliness. Furthermore, due to better definition of the sequence of movements during adjustment, the level of certainty for vehicle occupants can be improved.

[0031] This method can preferably be implemented in such a way that, in order to switch between a first adjustment range and a second adjustment range, the blocking device is switched between a first position and a second position, and the blocking device is switched between the second position and the first position. For example, the adjustment driver can be improved as described above.

[0032] Methods for adjusting one or more adjustment actuators can be advantageously used for adjusting the steering column, for example for longitudinal and / or vertical adjustment of the steering column. Attached Figure Description

[0033] Advantageous embodiments of the invention will now be described in more detail with reference to the accompanying drawings. In the various drawings:

[0034] Figure 1 A schematic perspective view of the steering column according to the invention is shown.

[0035] Figure 2 A schematic 3D diagram is shown based on Figure 1 The adjusting drive of the steering column according to the present invention,

[0036] Figure 3 It shows the passage along the axis (main axis) according to Figure 2 The longitudinal cross-section of the adjusting drive,

[0037] Figure 4 It shows Figure 3 A magnified detail image in the first position.

[0038] Figure 5 As shown in Figure 4 The view during the switch to the second position.

[0039] Figure 6 It shows the relationship with Figure 5 A similar view in the second position. Detailed Implementation

[0040] In the various figures, the same parts are always represented by the same reference numerals, and therefore will usually be identified or mentioned only once.

[0041] Figure 1A perspective view, tilted rearward relative to the direction of travel, shows the steering column 1 according to the invention. The steering column includes a positioning unit 2 for inputting steering commands, the positioning unit having a housing unit 3 with three housing tubes 31, 32, and 33, specifically an outer housing tube 31, a middle housing tube 32, and an inner tube 33. The housing tubes 31, 32, and 33 are arranged coaxially within each other and are arranged to be telescopingly movable in a longitudinal direction corresponding to the axial direction of the longitudinal axis L, as indicated by the double arrows. Here, an adjustment direction is referred to as the retraction direction E, which is also synonymously referred to as the forward adjustment direction E, along which the housing tubes 31, 32, and 33 move forward relative to the direction of travel and overlap each other, i.e., are retracted, so as to shorten the positioning unit 2 to a stowed position. Correspondingly, the adjustment direction opposite to the retraction direction E is the unfolding direction A or the rearward adjustment direction A as indicated by the corresponding arrow. The shell tubes 31, 32, and 33 move away from the retracted position in the direction of the operator's control position along this adjustment direction, that is, they are unfolded.

[0042] The steering spindle 4 is mounted in the housing unit 3 and is rotatable about the longitudinal axis L. The steering spindle has an attachment portion 41 at its rear end for attaching a steering wheel (not shown). The steering spindle 4 is also designed to extend and retract in the axial direction for longitudinal adjustment purposes.

[0043] The shell unit 3 is held in a two-piece support unit 5, which has a fastening device 51 for attaching to the vehicle body shell (not shown).

[0044] exist Figure 2 The adjustment actuator 6 shown separately is used for relative longitudinal adjustment of the shell tubes 31, 32 and 33, and the adjustment actuator 6 has an internally threaded spindle 61 and an externally threaded spindle 62 extending coaxially along the axis G and the direction of the spindle axis, and has a spindle nut 63. Figure 3 A longitudinal section along the axis G is shown, and Figure 4 , Figure 5 and Figure 6 It shows Figure 3 A magnified view of details.

[0045] The external thread spindle 62 is designed as a tubular hollow spindle and has an external thread 620 and an internal thread 621 coaxial with the external thread. The internal thread spindle 61 has an external thread 611, through which the internal thread spindle engages with the internal thread 621, and thus together with the external thread spindle 62, forms a first spindle mechanism.

[0046] The external thread spindle 62 is screwed into the internal thread 630 of the spindle nut 63 via its external thread 620, and together with the spindle nut 63 forms a second spindle mechanism, which is operatively nested with the first spindle mechanism and arranged in axial series.

[0047] The spindle nut 63 is rotatably mounted in the housing of the drive unit 64, enabling it to rotate about axis G, and is fixedly connected to a gear 65, for example, as in the illustrated example, which has a gear ring coaxially and fixedly connected to the spindle nut 63. The gear 65, together with the spindle nut 63, can be driven by an electric motor 66 to rotate about axis G to achieve the purpose of a motor-driven actuator for the spindle mechanism.

[0048] The internal thread spindle 61 is connected to the housing 33 in a manner that is fixed relative to rotation about axis G—that is, in a manner that is not rotatable relative to the adjustment drive 6.

[0049] The blocking device 7 according to the invention has a locking element constructed as a spherical member 71, which is received in a radial aperture 72 of the external threaded spindle 62 with clearance, and is held to be able to move laterally relative to the axis G, but is simultaneously axially supported. The aperture 72 may be constructed as a circular hole with an inner diameter larger than the diameter of the spherical member 71. The diameter of the spherical member 71 is sized such that the spherical member 71 protrudes radially inward or radially outward beyond the external threaded spindle 62.

[0050] The internally threaded spindle 61 has a radial recess 74 on its outer side, which forms an inner locking receiving portion. The spherical member 71 can engage with this inner locking receiving portion by inward displacement, as in... Figure 4 As can be seen in the image. Then, the recess 74 is connected to the orifice 72 in a form-fit manner by means of the spherical member 71. The blocking device 7 is thus in a second position, in which the internal thread spindle 61 is locked together with the external thread spindle 62 by a form fit for common rotation and is connected to the external thread spindle 62 for common rotation. The blocking device 7 is thus in a second position ( Figure 4 ).

[0051] The spindle nut 63 has a radial recess 73 on its inner side, in the region of its internal thread 630. This recess 73 forms an outer locking receiving portion, and the spherical member 71 can engage with this outer locking receiving portion in a form-fit manner by displacing it outward, as in... Figure 4 As can be seen, the recess 73 is connected to the orifice 72 in a form-fit manner by means of a spherical member 71. The blocking device 7 is thus in a first position, in which the externally threaded spindle 62 is locked together with and connected to the spindle nut 63 by a form fit for joint rotation. Figure 6 ).

[0052] The external threaded spindle 62 has a stop portion 622 at one end, which is in the form of a protrusion or collar. This stop portion 622 protrudes radially outward beyond the external thread, and when the external threaded spindle 62 has been retracted to its maximum extent in the retraction adjustment direction E (forward adjustment direction), the stop portion 622 can axially abut against the spindle nut 63. (See also...) Figure 6 .

[0053] Figure 3 and Figure 4 An example illustrates the adjustment of the steering column within either the comfort control range or the operator control range, where the housing tubes 31, 32, and 33 are extended longitudinally. If the spindle nut 63 is driven to rotate, the external thread spindle 62 is linearly driven along the forward adjustment direction E. The adjustment speed is determined by the pitch of the internal thread 630 and the corresponding external thread 620. Here, as... Figure 4 As shown, the internal thread spindle 61 is locked by means of the blocking device 7 to rotate together, so that the internal thread spindle and the external thread spindle 62 move and adjust linearly together.

[0054] At the end of the comfort range, the stop 622 axially abuts against the spindle nut 63, stopping the linear movement of the external thread spindle 62 relative to the spindle nut 63. Here, the... Figure 5 The switching position shown is in which the two recesses 73 and 74 are positioned radially opposite each other in the region of the orifice 72.

[0055] Therefore, during the position change, the spherical part 71 can be moved out of the recess 74, and as in Figure 5 As indicated by the arrow, the spherical member 71 moves outward in the orifice 72 until it engages with the outer recess 73 in a form-fit manner, as shown in the image. Figure 6 As illustrated in the figure. Therefore, the lock for the common rotation between the internal thread spindle 61 and the external thread spindle 62 is released, and the blocking device 7 switches to a first position in which the external thread spindle 62 is subsequently locked together with the spindle nut 63 for common rotation.

[0056] If the spindle nut 63 is driven to rotate further, the external thread spindle 62 rotates together with the spindle nut, and the internal thread spindle 61 adjusts linearly relative to the external thread spindle. Here, the adjustment speed is determined by the pitch of the internal thread 621 and the corresponding external thread 611. Since this pitch can be greater than the pitch of the thread between the external thread spindle 62 and the spindle nut 63, for a given rotational speed of the drive unit 64, faster adjustment can be achieved within the retracted range until the front retracted position is reached.

[0057] The recesses 73 and 74 may have actuating ramps that are inclined in the axial direction, so that the spherical member 71 passes through Figure 5 The switching position shown automatically moves inward or outward to switch between the first and second positions, or between the second and first positions, depending on the adjustment direction.

[0058] List of reference numerals

[0059] 1 Steering column

[0060] 2 positioning units

[0061] 3-shell unit

[0062] 31 Outer Tube

[0063] 32 intermediate shell tube

[0064] 33 Inner Shell Tube

[0065] 4 steering spindles

[0066] 41 Attachment

[0067] 5 support units

[0068] 51 Fastening device

[0069] 6 Adjustable Driver

[0070] 61 Internal Thread Spindle

[0071] 610 external thread

[0072] 62 External Thread Spindle

[0073] 620 external thread

[0074] 621 internal thread

[0075] 622 stop section

[0076] 63 spindle nut

[0077] 630 internal thread

[0078] 64 drive units

[0079] 65 gears

[0080] 66 motors

[0081] 7 blocking devices

[0082] 71 Spherical component (locking element)

[0083] 72-hole opening

[0084] 73, 74 Depression

[0085] L longitudinal axis

[0086] G-axis (main spindle axis)

[0087] E adjusts the direction forward (retracts the direction).

[0088] A. Adjust the direction backward (unfold adjustment direction)

Claims

1. An adjustment actuator (6) for a motor-adjustable steering column (1) of a motor vehicle, the adjustment actuator (6) comprising an externally threaded spindle (62) having an external thread (620) engaging with a spindle nut (63), and the externally threaded spindle having an internal thread (621) engaging with an internally threaded spindle (61), wherein, The main spindle nut (63), the external thread spindle (62), and the internal thread spindle (61) can be driven by a motor-type drive unit (64) to rotate relative to each other about an axis (G). Its features are, A blocking device (7) is provided that can switch between a first position and a second position, wherein in the first position, the external thread spindle (62) and the spindle nut (63) are locked together for joint rotation, and in the second position, the external thread spindle (62) and the internal thread spindle (61) are locked together for joint rotation.

2. The regulating driver (6) according to claim 1, characterized in that, The blocking device (7) interacts with the spindle nut (63), the external thread spindle (62) and the internal thread spindle (61) to switch from the second position to the first position in a forward adjustment direction (E) at a predetermined relative position, and to switch from the first position to the second position in a backward adjustment direction (A) opposite to the forward adjustment direction (E) at a relative position.

3. The regulating actuator (6) according to any one of claims 1-2, characterized in that, The blocking device (7) has a locking element (71) that can move between the first position and the second position.

4. The regulating actuator (6) according to claim 3, characterized in that, The locking element (71) is movably mounted on the external thread spindle (62) and can be selectively engaged with the locking reception (73) of the spindle nut (63) or with the locking reception (74) of the internal thread spindle (61).

5. The regulating driver (6) according to claim 4, characterized in that, The locking receiving portion (73, 74) has a recess (73, 74) formed in the spindle nut (63) and / or the internally threaded spindle (61).

6. The regulating driver (6) according to claim 3, characterized in that, The locking element (71) is arranged in the orifice (72) of the external thread spindle (62).

7. The regulating driver (6) according to claim 3, characterized in that, The spindle nut (63) has a first actuation device configured to switch the locking element (71) from the first position to the second position, and the internal thread spindle (61) has a second actuation device configured to switch the locking element (71) from the second position to the first position.

8. The regulating actuator (6) according to any one of claims 1-2, characterized in that, The external thread spindle (62) has a defining device (622) that allows the defining device (622) to abut against the spindle nut (63) in the axial direction.

9. The regulating actuator (6) according to any one of claims 1-2, characterized in that, The external thread (620) of the external thread spindle (62) and the internal thread (621) of the external thread spindle (62) have different pitches.

10. The regulating driver (6) according to claim 9, characterized in that, The internal thread (621) has a larger pitch than the external thread (620).

11. The regulating driver (6) according to claim 9, characterized in that, At least one of the internal thread (621) and the external thread (620) has a self-locking design.

12. A steering column (1) for a motor vehicle, the steering column (1) comprising an adjustment actuator (6) according to any one of claims 1 to 11, the adjustment actuator being disposed between housing tubes (31, 32, 33) of a housing unit (3) which are axially adjustable in a telescopic manner relative to each other and rotatably support a steering spindle (4), and / or the adjustment actuator being disposed between a support unit (5) capable of being connected to a body shell of the motor vehicle and the housing unit (3) rotatably receiving the steering spindle (4).

13. A method for operating the regulating actuator (6) according to any one of claims 1 to 11, Its features are, Within a first adjustment range, the external thread spindle (62) and the spindle nut (63) are locked together for joint rotation, and the external thread spindle (62) is driven to rotate relative to the internal thread spindle (61). Within a second adjustment range, the external thread spindle (62) and the internal thread spindle (61) are locked together for joint rotation, and the spindle nut (63) is driven to rotate relative to the external thread spindle (62).

14. The method according to claim 13, characterized in that, In order to switch between the first adjustment range and the second adjustment range, the blocking device (7) is switched between the first position and the second position, and the blocking device (7) is switched between the second position and the first position.

15. A method for adjusting a steering column (1) for a motor vehicle according to claim 12, wherein, The regulating driver (6) is operated according to the method of claim 13.

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