Electrically adjustable steering column with safety circuit and method for operating the electrically adjustable steering column.

Abstract

The present invention relates to an electrically adjustable steering column for a motor vehicle, the steering column comprising: an actuation unit on which a steering wheel may be disposed; a support unit on which the actuation unit is held in an adjustable manner by means of the support unit; and an adjustment device designed to adjust the actuation unit relative to the support unit, the adjustment device comprising an electric motor (55) for adjusting the actuation unit. The steering column also has a control unit (8) designed to start the electric motor (55). The control unit (8) is also designed to generate a first signal (S1) and a second signal (S2) to start the electric motor (55), wherein starting the electric motor (55) requires the application of the first signal (S1) and the second signal (S2), specifically the application of the first signal (S1) and the second signal (S2) to a first switching unit (12) and a second switching unit (13) of the control unit (8), the switching units being connected in series with the electric motor (55). The invention also relates to a method for operating such a steering column.

Description

Technical Field

[0001] This invention relates to an electrically adjustable steering column for a motor vehicle, the steering column comprising: a positioning unit on which a steering control element may be arranged; a support unit on which the positioning unit is adjustablely held; an adjustment device configured to adjust the positioning unit relative to the support unit, the adjustment device including at least one electric motor for adjusting the positioning unit; and a control unit configured to activate the at least one electric motor. The invention also relates to a method for operating the steering column, wherein, in order to adjust the positioning unit from a retracted position to an operating position by means of the steering column adjustment device, the steering column control unit activates at least one electric motor of the adjustment device. Background Technology

[0002] An electrically adjustable steering column is known from publication DE 10 2019 108 466A1, configured for adjustment between a retracted position and an operating position. In the operating position, corresponding to the extended position within the adjustment range, the vehicle can be controlled by the driver in a manual driving mode. In the retracted position, corresponding to the retracted position within the adjustment range, the vehicle can be automatically controlled in an automatic driving mode, particularly without driver intervention. To improve safety, the position of the steering column positioning unit relative to the support unit is determined. This determined position is particularly taken into account when vehicle restraint systems, such as airbags, are deployed.

[0003] Publication DE 10 2019 120 543A1 also discloses an adjustable steering column, wherein the actuation position of the positioning unit is detected. The detected actuation position is then evaluated to allow adjustment at a specific position within a specified range of allowable adjustment.

[0004] The possibility of adjusting the steering column between the retracted and operating positions, and thus the steering control elements arranged on the steering column, introduces new risks to the operation of the motor vehicle, as unintentional changes between the retracted and operating positions must be prevented in particular. This is because driver intervention is not possible in the retracted position, or driver intervention is limited to a certain range.

[0005] In this context, the object of the present invention is to provide an improved steering column that enables safer operation of the steering column. In particular, it aims to reduce the risk of unintentional retraction. Summary of the Invention

[0006] To achieve this objective, a steering column as claimed in the independent claims and a method for operating the steering column are proposed. Other advantageous embodiments of the invention are described in the dependent claims and the specification, and illustrated in the accompanying drawings.

[0007] The proposed solution provides an electrically adjustable steering column for a motor vehicle, wherein the steering column has: a positioning unit on which steering control elements, particularly a steering wheel, can be arranged; a support unit on which the positioning unit is adjustablely held; an adjustment device; and a control unit. The adjustment device is configured to adjust the positioning unit relative to the support unit, and includes at least one electric motor for adjusting the positioning unit. The control unit of the steering column is configured to start the at least one electric motor of the adjustment device and generate a first signal and a second signal for starting the at least one electric motor. The starting of the at least one electric motor requires the presence of the first and second signals. Therefore, advantageously, if only one of the signals is present, that is, for example, if only the first signal or only the second signal is present, the at least one electric motor is not started. Thus, in the event that one of the signals is unintentionally present, redundancy is advantageously created, which prevents the at least one electric motor from being unintentionally started, and thus prevents unintentional adjustment of the positioning unit. Such unintentional presence of the signal may be caused, for example, by a hardware failure, particularly by a hardware failure in the power electronics of the steering column, and especially by a hardware failure in the inverter of the steering column. For example, a permanently conductive MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) might unintentionally energize at least one electric motor. With the present invention, such unintentional energization is advantageously prevented because at least one other signal must be present for at least one electric motor to be energized.

[0008] Specifically, the first signal is configured to be a signal different from the second signal. Advantageously, the first signal and the second signal are two independent signals. Specifically, at least the first signal is generated independently of the second signal, or at least the second signal is generated independently of the first signal. Preferably, the first signal and / or the second signal are electrical signals.

[0009] According to an advantageous embodiment of the invention, a control unit having logic units is provided. The logic units are configured to generate a first signal and a second signal. Specifically, the logic units are configured to generate the first signal independently of the second signal. Specifically, the logic units are configured such that conditions that could lead to the generation of the first signal and the generation of the second signal are respectively tested for the generation of the first signal and the generation of the second signal. Advantageously, the corresponding logic components are redundantly present. Specifically, it is configured that a condition different from the condition for generating the first signal must be met for the generation of the second signal, and / or another condition must be met for the generation of the second signal.

[0010] Another particularly preferred embodiment involves at least one electric motor connected in series, wherein the at least one electric motor can be electrically connected in series to a voltage source. Specifically, when the steering column is constructed according to the invention and installed in a motor vehicle, at least one electric motor is electrically connected to a voltage source of the motor vehicle, particularly to a voltage source of the vehicle's onboard power supply.

[0011] More advantageously, the control unit of the steering column includes a first switching unit and a second switching unit. Advantageously, the first switching unit switches due to the presence of a first signal, and the second switching unit switches due to the presence of a second signal. That is, the first switching unit is specifically configured to switch when the first signal is present at the first switching unit, and the second switching unit is specifically configured to switch when the second signal is present at the second switching unit. In the positions of the switching units due to the presence of the first and second signals, it is advantageous to enable the starting of at least one electric motor. In particular, the logic unit is configured to start the first switching unit independently of the second switching unit.

[0012] According to another advantageous embodiment, the first and second switching units are connected in series with at least one electric motor. Therefore, it is specifically configured that the at least one electric motor can only be energized when the first and second switching units are each in a switching state in which a conductive connection is established between the first and second switching units and the voltage source, particularly the on-board power supply of the motor vehicle, and the at least one electric motor. Advantageously, the unintentional closing of only one switching unit will not result in the unintentional energization of the at least one electric motor.

[0013] Another advantageous embodiment involves a first switching unit comprising an inverter. Specifically, the first switching unit is an inverter. The inverter is advantageously configured to generate a motor start signal, particularly a motor start signal for at least one electric motor, based on a first signal. Specifically, the motor start signal is a voltage that can vary in level and / or frequency, particularly a voltage that varies according to the first signal.

[0014] According to another advantageous embodiment, the second switching unit includes a transistor, preferably a MOSFET. Specifically, the second switching unit is configured to be a transistor, preferably a MOSFET. The second signal here is specifically a switching voltage for switching the transistor.

[0015] Advantageously, the second switching unit is circuitally open when the second signal is absent, and circuitally closed when the second signal is present. Therefore, this means that in this embodiment, a conductive connection can only be established when the second signal is present. Specifically, for this purpose, the second switching unit is configured to include a self-turn-off MOSFET. Thus, an advantageous embodiment of the invention provides a series circuit comprising an inverter as a first switching unit, a MOSFET as a second switching unit, and an electric motor, wherein the inverter is controlled by means of the first signal, and the MOSFET is controlled by means of the second signal. Therefore, starting of the electric motor is possible only when both signals are present.

[0016] According to another advantageous embodiment variant, the second switching unit is configured to close (i.e., conduct electricity) when the second signal is present, and open (i.e., not conduct electricity) when the second signal is absent. In normal operation, the second signal advantageously exists permanently at the second switching unit. In this embodiment variant, the control unit includes a diagnostic unit configured to detect faults related to the starting of at least one electric motor. The control unit is further configured to interrupt the existing second generated signal if the diagnostic unit has detected a fault related to the starting of at least one electric motor, thus deviating from normal operation. In this case, the second signal may in particular be a no-voltage signal, and the second switching unit may be a self-conducting MOSFET. Here, interruption of the second signal means that a voltage is applied to the self-conducting MOSFET, causing the MOSFET to turn off.

[0017] The proposed advantageous improvement to the steering column involves a steering column control unit further configured to generate a second signal upon receiving a request signal for adjusting the positioning unit and an activation signal via the steering column interface. This activation signal is generated by the driver of the vehicle, or by the vehicle itself. Specifically, the request signal can be triggered by actuation of an operating element, which the vehicle user can use to adjust the steering column. A request signal can be additionally triggered, particularly when the driver wishes to switch between manual and automatic driving modes. Furthermore, the request signal can be triggered, particularly when the vehicle has detected a specific state associated with steering column adjustment, such as adjustments to reduce the risk of injury in the event of a vehicle accident, or adjustments to facilitate the driver's entry into or exit from the vehicle.

[0018] According to another advantageous embodiment, the steering column includes an interface, particularly a first interface, for connecting the steering column to the vehicle's on-board power supply. Advantageously, through this interface, the connection between the steering column and the on-board power supply, and advantageously, the connection of at least one electric motor of the steering column adjustment device, particularly as proposed, can be readily achieved when the steering column is installed in the vehicle. More advantageously, the steering column includes an interface, particularly a second interface, for connecting the steering column to the vehicle's central control unit. Advantageously, through this interface, signal transmission between the steering column control unit and the vehicle's central control unit becomes possible.

[0019] According to another advantageous embodiment, the control unit is configured to actuate at least one electric motor of the steering column adjustment device, causing the steering column positioning unit to move from the retracted position to the operating position or from the operating position to the retracted position. The control unit is also specifically configured here to receive a confirmation signal from the vehicle's central control unit via an interface of the steering column, particularly via a second interface. This confirmation signal is advantageously sent by the vehicle's central control unit when the vehicle is in automatic driving operation or when the vehicle is stationary. In automatic driving operation and when the vehicle is stationary, manual steering intervention by the driver is unnecessary, allowing adjustments between the operating and retracted positions to be made generally without risk when the vehicle is in these states. In other vehicle states, movement from the operating position to the retracted position is advantageously prevented.

[0020] Similarly, the method for operating the steering column proposed to achieve the fundamental object of the invention is specifically configured such that the steering column is used in a motor vehicle as intended. Specifically, the steering column is constructed according to the invention, having the aforementioned features individually or in combination. The proposed method is configured such that, in order to adjust the positioning unit by means of an adjusting device of the steering column, particularly to adjust the positioning unit from the retracted position of the steering column to the operating position of the steering column, the control unit of the steering column activates at least one electric motor of the adjusting device. To activate at least one electric motor, the control unit generates a first signal and a second signal, wherein the first signal is applied to a first switching unit and the second signal is applied to a second switching unit. The first and second switching units are preferably connected in series with at least one electric motor. When the first signal is present at the first switching unit and the second signal is also present at the second switching unit, at least one electric motor advantageously adjusts the positioning unit. That is, the first and second signals must, in particular, be present simultaneously at the respective switching units in order to brake the electric motor of the adjusting device and thus adjust the positioning unit.

[0021] Advantageously, the method further includes a configuration whereby an adjustment request is received by the steering column control unit, wherein a first signal is generated upon receiving the adjustment request. Advantageously, the control unit also receives an activation signal from driver input or from the vehicle controller, wherein a second signal is generated upon receiving the activation signal. Specifically, the method is configured such that, upon transitioning from manual to automatic driving operation, the vehicle's central control unit sends an adjustment request, wherein, in this example, the adjustment request specifically provides for adjustment of the steering column from the operating position to the retracted position. However, for the adjustment process from the operating position to the retracted position to be actually performed, it is advantageous that an activation signal has been received and that the second signal is present. Specifically, the method is configured such that the driver is required to confirm that the adjustment process has been performed. This driver confirmation is advantageously achieved through actuation of an input element, wherein, upon actuation of the input element, the steering column control unit receives the activation signal and generates the second signal. Without driver confirmation, the positioning unit is advantageously not adjusted. As a particularly advantageous alternative, the configuration involves the central control unit of the vehicle confirming, specifically by evaluating signals from at least one sensor, that a transition from manual to automatic driving has occurred, and generating an activation signal upon confirmation. Upon receiving the activation signal again, the control unit generates a second signal and can then execute the adjustment process. Without confirmation, the control unit does not receive the activation signal and advantageously does not execute the adjustment process. Attached Figure Description

[0022] Other advantageous details, features, and design details of the invention will be explained in more detail with reference to the exemplary embodiments shown in the accompanying drawings (Figure: Figures), in which:

[0023] Figure 1 An exemplary embodiment of a steering system having a steering column constructed according to the present invention is shown in a simplified perspective view;

[0024] Figure 2 An exemplary embodiment of a steering column constructed according to the present invention is shown in a simplified perspective view;

[0025] Figure 3 A simplified 3D diagram is shown based on... Figure 2 Exemplary implementations;

[0026] Figure 4 illustrates, in a highly simplified schematic diagram, an exemplary embodiment of an installed steering column constructed according to the present invention, having a retracted position. Figure 4a ) and in the operating position ( Figure 4b Steering control elements;

[0027] Figure 5 An exemplary embodiment of a steering column control unit constructed according to the present invention is illustrated in schematic diagram. This control unit activates an electric motor connected to an onboard power source; and

[0028] Figure 6 Another exemplary embodiment of a control unit for a steering column constructed according to the present invention is illustrated in schematic diagram. This control unit activates an electric motor connected to an onboard power source.

[0029] In various accompanying drawings, the same parts are usually given the same reference numerals, and therefore sometimes only one of the accompanying drawings will be used for interpretation. Detailed Implementation

[0030] Figure 1An exemplary embodiment of a steering system 10 is shown, which, as an example, takes the form of a steer-by-wire system. The steering system 10 includes a steering column 1 having a positioning unit 2 on which a steering wheel, serving as a steering control element 20, is arranged. The steering column 1 also includes a support unit 4, by which the positioning unit 2 is held in an adjustable manner. A rotation angle sensor (not shown) is mounted on the steering shaft of the positioning unit 2, which detects the driver's steering torque applied by the rotation of the steering control element 20. A feedback actuator 25 is also arranged on the steering shaft, which transmits feedback from the road 70 to the steering control element 20, and thus provides feedback to the driver regarding the vehicle's steering and driving behavior. The driver's steering intention is transmitted via a signal line to the control unit (in...) through the rotation angle of the steering shaft measured by the rotation angle sensor. Figure 1 (Not explicitly shown). The control unit activates the electric steering actuator 26 based on signals from the rotation angle sensor and other input variables, particularly vehicle speed or yaw rate. The steering actuator 26 controls the position of the steering wheel 27. The steering actuator 26 achieves axial displacement of the rack by means of a screw driver 28. The steering wheel 27 is connected to the rack via a tie rod 29.

[0031] The following will refer to Figure 2 and Figure 3 An exemplary embodiment of the steering column 1 for such a steering system 10 will be explained in more detail.

[0032] Figure 2 A schematic perspective view, taken from the upper left of the rear end portion based on the vehicle's direction of travel (not shown), illustrates an exemplary embodiment of a steering column 1 constructed according to the invention, wherein a steering wheel (not shown) remains within the operating range. Figure 3 The steering column 1 is shown in a view taken from the opposite side, i.e., from the upper right.

[0033] The steering column 1 includes a positioning unit 2, wherein a steering control element may be arranged on the steering shaft 37 of the positioning unit 2. The positioning unit 2 is held in an adjustable manner by a support unit 4. In order to adjust the positioning unit 2 relative to the support unit 4, the steering column includes an adjustment device 7, which in this exemplary embodiment includes two adjustment devices 5 and 6, each having an electric motor 55 and 65, respectively.

[0034] In this exemplary embodiment, the steering column 1 further includes a housing unit 3 having an outer housing tube 31, an intermediate housing tube 32, and an inner housing tube 33. The housing tubes 31, 32, and 33 are axially arranged along the axial direction of the longitudinal axis L so as to be coaxially adjustable within each other in a nested telescoping manner, as indicated by the double arrows.

[0035] A stop 34 is installed at the rear end of the outer shell tube 31, protruding inward at its open end into the gap between the outer shell tube 31 and the intermediate shell tube 32. During extension, the intermediate shell tube 32 axially abuts against the stop 34 and is secured to prevent separation from the outer shell tube 31. A stop 35 is installed at the rear end of the intermediate shell tube 32, protruding inward into the gap between the intermediate shell tube 32 and the inner shell tube 33 and securing the inner shell tube 33 to prevent it from being pulled out of the intermediate shell tube 32.

[0036] The steering spindle 37 is mounted in the housing unit 3 to be rotatable about the longitudinal axis L, and has a connecting portion 38 at its rear end for attaching a steering control element (in... Figure 2 and Figure 3 (Not shown in the diagram). Similar to housing unit 3, steering spindle 37 is also configured to telescop and extend in the longitudinal direction. The positioning unit 2 of steering column 1 includes inner housing tube 33 and steering spindle 37 mounted in inner housing tube 33. To achieve longitudinal adjustment relative to housing unit 3, positioning unit 2 is held in outer housing tube 31 so that it can be displaced in the direction of longitudinal axis L in a telescoping manner, allowing steering control elements that can be connected to steering spindle 37 to be positioned forward and backward relative to support unit 4 in the longitudinal direction, as indicated by the double arrows parallel to longitudinal axis L.

[0037] The housing unit 3 is held in the two-piece support unit 4, which has fastening devices 41 (not shown) for connecting to the vehicle body.

[0038] In the front region of housing unit 3, housing unit 3 is mounted to pivot relative to the vehicle body about a horizontal pivot axis S, schematically oriented transversely to the longitudinal axis L. For this purpose, a pivot bearing (not shown) is arranged in support unit 4 or between support unit 4 and the vehicle body. In the rear region, housing unit 3 is connected to support unit 2 via an actuating rod 42. Figure 3 As shown, the housing unit 3 can be adjusted and pivoted together with the positioning unit 2 relative to the support unit 4 about the pivot axis S which is horizontally positioned in the installed state, by means of the adjustment unit 6 of the adjustment device 7 of the steering column 1 via the actuating rod 42. In particular, the steering control element that can be attached to the fastening part 38 can be adjusted in the vertical direction H indicated by the double arrows.

[0039] like Figure 2As shown, another adjustment unit 5 of the steering column 1 adjustment device 7 is specifically configured for longitudinal adjustment of the positioning unit 2 relative to the housing unit 3 in the direction of the longitudinal axis L. In this exemplary embodiment, the other adjustment unit 5 has a spindle driver with a spindle nut 51 having an internal thread 74 extending along the spindle axis G. A threaded spindle 52 engages in this internal thread 74, that is, the threaded spindle 52 is screwed into the corresponding internal thread 74 of the spindle nut 51 via its external thread. In this exemplary embodiment, the threaded spindle axis of the threaded spindle 52 is the same as the spindle axis G and extends substantially parallel to the longitudinal axis L.

[0040] The spindle nut 51 is mounted in a bearing housing 53 to be rotatable about the spindle axis G, and the bearing housing 53 is fixedly connected to the outer casing tube 31 of the housing unit 4. In the direction of the spindle axis G, the spindle nut 51 is axially supported on the housing unit 4 by the bearing housing 53. In this exemplary embodiment, the adjusting unit 5 corresponds to a so-called plunger-type spindle drive.

[0041] The threaded spindle 52 is connected to the inner housing tube 33 at its free end by being rotatably and axially fixed to the arm 36, and the spindle nut 51 is axially, i.e., longitudinally, supported on the outer housing tube 31 by the drive unit 53. This longitudinal direction corresponds to the direction of the longitudinal axis L. By means of relative rotation of the adjusting device 7 by means of the electric motor 55, the threaded spindle 52 and the spindle nut 51 move together or separately according to the direction of rotation, thereby moving the inner housing tube 33 into or out of the intermediate housing tube 32, and the intermediate housing tube into or out of the outer housing tube 31, as indicated by the double arrows. A steering wheel, which can be attached to the connecting part 38, can thus be moved forward as follows: Figure 4a The collapse position is outlined in section 200, or you can move it to, for example... Figure 4b The operating positions 204, 205, and 206 within the operating range are outlined below. In the retracted position 200, the inner shell tube 33 and the intermediate shell tube 32 have been moved into the outer shell tube 31, i.e., pushed forward. In the operating positions 204, 205, and 206, the shell tubes 31, 32, and 33 have been moved out of each other in a nested telescopic manner.

[0042] From the location Figure 2 A perspective view of the steering column 1 is shown on one side of the rear section. Figure 3The diagram shows how the adjustment unit 6 of the adjustment device 7 is attached to the steering column 1 for adjustment in the vertical direction H. The adjustment unit 6 is constructed in principle in the same manner as the other adjustment unit 5 of the adjustment device 7. The adjustment unit 6 also includes a spindle nut 61, and a threaded spindle 62 engages in the internal thread of the spindle nut 61 along the spindle axis G. The threaded spindle 62 is mounted in a bearing housing 63 so as to be rotatable about the axis G. The bearing housing 63 is fastened to the housing unit 3 and axially supported on the housing unit 3 along the axis G, and can be driven in a rotational manner in both rotational directions about the axis G by an electric motor 65.

[0043] In the illustrated embodiment, the adjustment units 5 and 6 of the steering column 1 are so-called plunger-type spindle drives. Alternatively, particularly, a rotary spindle drive can also be formed, in which the spindle nut 51 is held on the steering column 1 in terms of rotation, and the threaded spindle 52 can be driven in a rotary manner by a motor 55.

[0044] The adjusting unit 6 engages the end of the double-arm actuator 42, which is mounted on the support unit 4 to be able to rotate about the pivot bearing 43, and the other arm of the double-arm actuator 42 is connected to the housing unit 3 at the other end in another pivot bearing 44.

[0045] In order to regulate the starting of the electric motors 55 and 65 of the regulating device 7, the steering column 1 includes a control unit 8, which... Figure 2 and Figure 3 It is only symbolically shown in the text. (Through...) Figure 2 and Figure 3 Lines Z1 and Z2, also shown only symbolically, connect control unit 8 to electric motors 55 and 65. Control unit 8 is configured to generate a first signal S1 for starting the electric motors and a second signal S2 independent of the first signal. Control unit 8 includes a first switching unit 12 and a second switching unit 13, wherein the first switching unit 12 switches due to the presence of the first signal S1, and the second switching unit 13 switches due to the presence of the second signal S2. Starting electric motors 55 and 65 requires the presence of both the first signal S1 and the second signal S2. (Refer to...) Figure 5 and Figure 6 Further details regarding the possible configuration of control unit 8 are explained.

[0046] Steering column 1 also includes interface 9, interface 9 in Figure 2 and Figure 3The image is also shown only symbolically. Through interface 9, the steering column can be connected to the vehicle's onboard power supply, specifically to provide the electrical energy required to regulate the electric motors 55 and 65. The steering column 1 can also be connected to the vehicle's central control unit via interface 9. In this way, the steering column's control unit 8 can advantageously exchange data with the central control unit. In particular, the vehicle's autonomous driving operation can be communicated to the control unit 8 via interface 9, which may be a requirement to adjust the positioning unit 2 from operating positions 204, 205, 206 to the retracted position 200.

[0047] Reference Figure 4a and Figure 4b The embodiments of the present invention will be further explained, and in particular the operation of the steering column 1 as provided in the present invention will be explained. Figure 4a and Figure 4b Details of a motor vehicle 48, including a steering column 1 constructed according to the invention, are shown in a highly simplified form, particularly as shown in reference 1. Figure 2 and Figure 3 The steering column as described.

[0048] Here, the steering wheel, which serves as the steering control element 20, is positioned on the positioning unit 2 of the steering column 1. Figure 4a In this configuration, the steering control element 20 is arranged in a retracted position 200, which provides the driver with maximum room for maneuver. In particular, the retracted position 200 can be assumed to be in the automatic driving mode of the motor vehicle 48, in which no steering intervention from the driver is required.

[0049] On the other hand, Figure 4b In this configuration, the steering control element 20 is arranged in operating positions 204, 205, and 206, in which the driver can manually steer the vehicle 48 via the steering control element 20. Operating positions 204, 205, and 206 are preferably individually assigned to each driver, or preset by the driver before first use of the vehicle. The actual operating positions 204, 205, and 206 particularly depend on the driver's height and personal preference. That is, the operating positions are not absolute positions, but rather located within an operating range, which can specifically be located between a first position and a second position, for example, anywhere between operating positions 204 and 206.

[0050] In order to utilize the adjustment device 7 of the steering column 1 (in Figure 4a and Figure 4b(Not explicitly shown) To adjust the positioning unit 2 from operating positions 204, 205, 206 to the retracted position 200, the control unit 8 of the steering column 1 must activate the motor of the adjustment device 7. For this purpose, the control unit generates a first signal S1 and a second signal S2, specifically by means of a logic unit constructed accordingly for this purpose. The first signal S1 is applied to the first switching unit 12, and the second signal S2 is applied to the second switching unit 13. Here, when the first signal S1 is present at the first switching unit 12 and the second signal S2 is present at the second switching unit 13, the motor of the adjustment device 7 adjusts the positioning unit 2.

[0051] Specifically, the driver of the motor vehicle 48 can send an adjustment request to move the steering control element 20 from the operating positions 204, 205, 206 to the retracted position 200. For example, the adjustment request can be sent by pressing switch 14. The adjustment request is then received by the control unit 8, whereby a first signal S1 is generated upon receipt. The adjustment request can also be received by the central control unit of the motor vehicle 48. The central control unit checks whether a state can be authorized for activation exists. Such a state is, in particular, automatic driving operation without detected abnormalities. If such a state exists, the central control unit sends an activation signal to the control unit 8 of the steering column 1. This activation signal is received by the control unit 8, whereby a second signal S2 is generated upon receipt. Therefore, the first signal S1 and the second signal S2 are present simultaneously, and the motor of the steering column 1 adjustment device 7 is activated by the control unit 8, causing the positioning unit 2, and thus the steering control element 20, to move from the operating positions 204, 205, 206 to the retracted position 200. However, if the central control unit determines that there is no automatic driving operation or that the automatic driving operation must be terminated due to a dangerous situation, the activation signal will not be sent to the control unit 8 of the steering column 1, and the second signal S2 will not be generated. Therefore, despite the presence of the request signal, the motor of the adjustment device 7 is not started in this case, and the positioning unit 2 and therefore the steering control element 20 remain in the operating positions 204, 205, 206.

[0052] The following will refer to Figure 5 An advantageous exemplary embodiment of the steering column control unit 8 constructed according to the present invention is explained. (As in conjunction with...) Figure 2 , Figure 3 , Figure 4a and Figure 4b As described, a control unit 8 specifically configured for use with the steering column 1 can be provided. Figure 5A control unit 8, specifically in the form of an ECU (Electronic Control Unit) and a steering column, is schematically shown. The control unit 8 includes a first switching unit 12, a second switching unit 13, and a logic unit 81. The logic unit 81 is configured to switch between the first switching unit 12 and the second switching unit 13. Specifically, the first switching unit 12 is an inverter. Also specifically, the second switching unit 13 is a field-effect transistor, preferably a self-turn-off MOSFET.

[0053] The electric motor 55 of the steering column adjustment device is connected to the vehicle's on-board power supply 87 via a first switching unit 12 and a second switching unit 13. The electric motor 55, the first switching unit 12, and the second switching unit 13 are electrically connected in series with the voltage source of the on-board power supply 87.

[0054] To switch the first switching unit 12, the logic unit 81 must generate a first signal S1, and to switch the second switching unit 13, the logic unit 81 must generate a second signal S2. In this exemplary embodiment, it is configured such that if the first signal S1 is absent at the first switching unit 12 and the second signal S2 is absent at the second switching unit 13, the conductive connection between the voltage source of the vehicle power supply 87 and the electric motor 55 will be disconnected by both the first switching unit 12 and the second switching unit 13. Therefore, in order for the electric motor 55 to be started for adjusting the positioning unit of the steering column, and thus also for adjusting the steering control element, the first signal S1 must be present at the first switching unit 12 and the second signal S2 must be present at the second switching unit 13, and therefore a motor start signal SM must be generated. The first signal S1 is generated by the logic unit 81 independently of the second signal S2. In particular, it can be configured such that when changing from a manual driving mode in which the steering control element is in the operating position to an automatic driving mode in which the steering control element can be in the retracted position, the first signal S1 is automatically generated by the logic unit 81. The conditions for generating the second signal S2 can be, in particular, that the first signal S1 has already been generated, and that a confirmation signal indicating that the vehicle is in autonomous driving mode is received by the logic unit 81. For example, the second signal S2 can be generated by an AND gate fed by the first signal S1 and the confirmation signal.

[0055] Figure 6 It shows that according to Figure 5 Variations of the exemplary implementation. In accordance with... Figure 6In a variant of the implementation, the control unit 8 is further configured to include a diagnostic unit 82, which may in particular be part of the logic unit 81. Here, the second signal S2 is controlled by the diagnostic unit 82, wherein the second signal S2 is normally always present. The diagnostic unit 82 monitors for malfunctions in the starting of the electric motor 55. Such a malfunction could be, for example, a command to move the steering control element to a retracted position to allow easy access to the driver's seat, the so-called easy-access function, even while the vehicle is moving. In the event of such a malfunction, the diagnostic unit 82 interrupts the second signal S2, thereby disconnecting the conductive connection between the vehicle power supply 87 and the electric motor 55, and the steering control element does not move to the retracted position. For diagnostic purposes, the second switching unit 13 may be briefly connected. In this case, the diagnostics specifically include at least one current and / or voltage measurement of at least one first signal S1 present at the first switching unit 12 and / or the second signal S2 present at the second switching unit 13.

[0056] The exemplary embodiments shown in the accompanying drawings and described in conjunction with the drawings are used to illustrate the present invention and are not intended to limit the invention.

[0057] List of reference numerals

[0058] 1. Steering column

[0059] 2 Positioning Unit

[0060] 3 shell units

[0061] 31 Outer casing tube

[0062] 32 Intermediate shell tube

[0063] 33 Inner shell tube

[0064] 34, 35 Stop pieces

[0065] 36 arms

[0066] 37 Steering spindle

[0067] 38 Connection Part

[0068] 4 Support Units

[0069] 41 Fastening devices

[0070] 42 Actuating rod

[0071] 43, 44 Pivot bearings

[0072] 48 Motor vehicles

[0073] Adjustment units 5 and 6

[0074] 51, 61 Spindle Nuts

[0075] 52 and 62 threaded spindles

[0076] 53, 63 bearing housings

[0077] 542 Fastening Bolt

[0078] 55 and 65 electric motors

[0079] 7. Adjustment device

[0080] 8 Control Unit

[0081] 81 Logic Units

[0082] 82 Diagnostic Units

[0083] 87 Vehicle Power Supply

[0084] 89 Voltage Source

[0085] 9 Interfaces

[0086] 91 Interface for connecting to vehicle power supply

[0087] 92 Interface for connecting to the central control unit of a motor vehicle

[0088] 10. Steering System

[0089] 12 First Switching Unit

[0090] 13 Second Switching Unit

[0091] 20 Steering control elements

[0092] 25 Feedback actuator

[0093] 26 Steering actuator

[0094] 27 rounds

[0095] 28 Screw Driver

[0096] 29. Pull rod

[0097] 70 Ground

[0098] 74 Internal Thread

[0099] L longitudinal axis

[0100] S Pivot axis

[0101] G. Spindle axis (threaded spindle axis)

[0102] S1 First Signal

[0103] S2 Second Signal

[0104] SM, SM1, SM2 motor start signals

[0105] Z1 and Z2 lines

Claims

1. An electrically adjustable steering column (1) for a motor vehicle, the steering column (1) comprising: The positioning unit (2) is provided with a steering control element (20); The support unit (4) holds the positioning unit (2) in an adjustable manner; an adjustment device (7) configured to adjust the positioning unit (2) relative to the support unit (4), and the adjustment device (7) includes at least one electric motor (55, 65) for adjusting the positioning unit (2); and a control unit (8) configured to start the at least one electric motor (55, 65), characterized in that the control unit (8) is further configured to generate a first signal for starting the at least one electric motor (55, 65). (S1) and the second signal (S2), wherein the start-up of the at least one electric motor (55, 65) requires the presence of the first signal (S1) and the second signal (S2); the control unit (8) includes a first switch unit (12) and a second switch unit (13), wherein the first switch unit (12) is switched due to the presence of the first signal (S1), and the second switch unit (13) is switched due to the presence of the second signal (S2); the first switch unit (12) and the second switch unit (13) are connected in series with the at least one electric motor (55, 65).

2. The steering column (1) according to claim 1, characterized in that, The control unit (8) has a logic unit (81) for generating the first signal (S1) and the second signal (S2).

3. The steering column (1) according to claim 1 or 2, characterized in that, The at least one electric motor (55, 65) is connected in series, wherein the at least one electric motor (55, 65) can be electrically connected in series to a voltage source (89) through the series connection.

4. The steering column (1) according to claim 1 or 2, characterized in that, The first switching unit (12) includes an inverter, wherein the inverter is configured to generate motor start signals (SM, SM1, SM2) according to the first signal (S1).

5. The steering column (1) according to any one of claims 1 to 2, characterized in that, The second switching unit (13) includes a transistor, wherein the second signal (S2) is a switching voltage for switching the transistor.

6. The steering column (1) according to any one of claims 1 to 2, characterized in that, When the second signal (S2) is not present, the second switch unit (13) is open, and when the second signal (S2) is present, the second switch unit (13) is closed.

7. The steering column (1) according to any one of claims 1 to 2, characterized in that, The control unit (8) includes a diagnostic unit (82) configured to detect a fault in the starting of the at least one electric motor (55, 65), wherein the control unit (8) is further configured to interrupt a present second signal (S2) if the diagnostic unit (82) has detected a fault in the starting of the at least one electric motor (55, 65), and the second switch unit (13) is closed when the second signal (S2) is present, and is open when the second signal (S2) is absent.

8. The steering column (1) according to any one of claims 1 to 2, characterized in that, The control unit (8) is further configured to generate the second signal (S2) when the control unit (8) receives a request signal for adjusting the positioning unit (2) and the control unit (8) receives an activation signal through the interface of the steering column (1), wherein the activation signal is a signal generated by the driver of the motor vehicle or a signal generated by the motor vehicle.

9. The steering column (1) according to claim 2, characterized in that, The logic unit (81) is configured to activate the first switch unit (12) independently of the second switch unit (13).

10. The steering column (1) according to any one of claims 1-2, characterized in that, The first interface (91) is used to connect the steering column (1) to the vehicle's on-board power supply and / or the second interface (92) is used to connect the steering column (1) to the vehicle's central control unit.

11. The steering column (1) according to any one of claims 1-2, characterized in that, The control unit (8) is further configured to activate at least one electric motor (55, 65) of the adjustment device (7) to move the positioning unit (2) from the retracted position (200) to the operating position (204, 205, 206) or from the operating position (204, 205, 206) to the retracted position (200), wherein the control unit (8) is further configured to receive an acknowledgment signal from the control unit of the motor vehicle via an interface of the steering column (1), wherein the acknowledgment signal is sent by the control unit of the motor vehicle when the motor vehicle is in automatic driving operation or when the motor vehicle is stationary.

12. A method for operating a steering column according to any one of claims 1 to 11, wherein, In order to adjust the positioning unit (2), the control unit (8) of the steering column (1) activates at least one electric motor (55, 65) of the adjustment device (7), characterized in that, in order to activate the at least one electric motor (55, 65), the control unit (8) generates a first signal (S1) and the control unit (8) generates a second signal (S2), wherein the first signal (S1) is applied to a first switching unit (12) and the second signal (S2) is applied to a second switching unit (13), wherein when the first signal (S1) is present at the first switching unit (12) and the second signal (S2) is present at the second switching unit (13), the at least one electric motor (55, 65) adjusts the positioning unit (2).

13. The method according to claim 12, characterized in that, The control unit (8) receives an adjustment request, wherein upon receiving the adjustment request, the first signal (S1) is generated, and the control unit (8) receives an enable signal from the driver input or the vehicle controller, wherein upon receiving the enable signal, the second signal (S2) is generated.

14. The method according to claim 12, characterized in that, In order to adjust the positioning unit (2) between the retracted position (200) and the operating position (204, 205, 206) by means of the adjustment device (7) of the steering column (1), the control unit (8) of the steering column (1) activates at least one electric motor (55, 65) of the adjustment device (7).

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