Steering column for a motor vehicle

Abstract

The invention relates to a steering column (1) for a motor vehicle, having two parts (3, 4) which are adjustable relative to one another in two non-parallel adjustment directions (L, H) and a position detection device (7) having a sensor which is connected to one part (3) and comprises at least one sensor unit (72) and having a sensor target which is connected to the other part (4) and comprises at least one target unit (71), the sensor being configured to detect the relative position of the sensor target. In order to be able to carry out the position detection in both adjustment directions with less effort, it is proposed that the target unit (71) has a measuring portion which extends in both adjustment directions (L, H) and has a local measuring quantity which varies in each of the two adjustment directions (L, H) and which can be detected locally by the sensor unit (72).

Description

Technical Field

[0001] This invention relates to a steering column for a motor vehicle, the steering column having two components adjustable relative to each other in two non-parallel adjustment directions, and a position detection device having a sensor connected to one component and including at least one sensor unit, and a sensor target connected to the other component and including at least one target unit, the sensor being configured to detect the relative position of the sensor target. The invention also relates to a method for operating such a steering column. Background Technology

[0002] This type of steering column has a manual steering handle, such as a steering wheel, that can rotate about a longitudinal axis in a setting unit at its rear end facing the driver relative to the vehicle's direction of travel. At a distance from the side end of this steering wheel, the steering column is typically secured to the vehicle body in the side region via a support unit.

[0003] To adapt the steering wheel position to the driver's position in a user-friendly manner, the steering handle is configured to be positioned relative to the vehicle body in a longitudinal direction defined by the longitudinal axis for longitudinal adjustment, and the steering handle can be positioned laterally to the longitudinal direction in a height direction for height adjustment. To achieve longitudinal adjustment, a setting unit carrying the steering handle can be retractably housed in a housing unit, also referred to as a guide box or box rocker, in the longitudinal direction, which defines a first adjustment direction. Height adjustment is possible because the housing unit is mounted on a support unit in the front region to be pivotable or displaceable about a horizontal axis, allowing the steering handle to pivot in the height direction, which defines a second adjustment direction of the setting unit relative to the support unit, a second adjustment direction that is not parallel to the longitudinal direction.

[0004] To automatically set individual steering wheel positions for optimal activation of steering column-related safety systems, or to adjust the steering column from its operating position to a retracted position outside its operating range during autonomous driving operations of an automated vehicle, it is necessary to detect the corresponding current adjustment position in two adjustment directions. For this purpose, in the prior art, for example from DE 10 2020 202 536 A1, a steering column with a position detection device is known, having a sensor and a sensor target interacting with the sensor for detecting the position of components movable relative to each other. For this purpose, a sensor unit is provided for each of the two adjustment directions, connected to a component, such as a housing unit or support unit, and interacting with a target unit fixed to another component, such as a housing unit or support unit, which can be adjusted relative to said component. For each of the two adjustment directions, a sensor pair formed by the sensor unit and the corresponding target unit is provided, each sensor pair having a one-dimensional measuring portion extending linearly in the corresponding adjustment direction. Therefore, in each case, the relative positioning of the two adjustable components in the adjustment direction can be detected by the sensor unit and the associated target unit, and can be transmitted as an electrical measurement signal to the electronic control unit. The electronic control unit can then generate an electrical control signal and control the electric actuator to automatically adjust the steering column in both adjustment directions, for example, to the folded-back position or the safe position.

[0005] Because known position detection devices require a sensor unit and a corresponding target unit for each of the two adjustment directions in every case, this results in relatively high manufacturing and assembly costs as well as high installation space requirements.

[0006] In view of the above problems, the object of the present invention is to enable position detection in two adjustment directions at a lower cost. Summary of the Invention

[0007] According to the present invention, this objective is achieved by the steering system of the present invention.

[0008] In the case of a steering column for a motor vehicle, the steering column has a position detection device and two components adjustable relative to each other in two non-parallel adjustment directions. The position detection device has a sensor connected to one component and including at least one sensor unit, and a sensor target connected to the other component and including at least one target unit. The sensor is configured to detect the relative position of the sensor target. According to the invention, the position detection device is configured such that the target unit has a measuring portion extending in the two adjustment directions, the measuring portion having a local measurement quantity varying in each of the two adjustment directions, the local measurement quantity being locally detectable by the sensor unit.

[0009] In the following text, the two adjustment directions are also referred to as the two adjustment directions. The operational combination of the sensor unit and the associated target unit can also be referred to as a sensor pair.

[0010] The difference in the target unit configured according to the present invention lies in that the target unit has a two-dimensional effective measuring portion, which is adapted to achieve position measurement in two non-parallel measuring directions. The target unit preferably extends parallel to the measuring plane traversed by the two adjustment directions. The surface of the measuring portion that can be used for position measurement forms a two-dimensional measuring surface, which may be identical to the total surface area of ​​the measuring portion.

[0011] In each defined surface portion of the measuring section, or at each point corresponding to the defined surface coordinates within the measuring section, the measuring section has a locally defined measurement quantity that varies, for example, by a gradient, within a range in each of two possible adjustment directions. For example, at any point in the longitudinal range, the measurement quantity may increase in the longitudinal direction and increase in the height direction transverse to that longitudinal direction. In this case, viewed in the adjustment direction, the trace of the measurement quantity may be linear, nonlinear, continuous, or discontinuous.

[0012] One advantage is that local measurements can be detected using a single sensor unit. In this case, the determined local measurement can be simultaneously associated with the longitudinal and height positions of the adjustable components relative to each other. This measurement can be referred to as a two-dimensional measurement compared to two separate one-dimensional measurements in the prior art. Accordingly, the sensor according to the invention (and thus can be referred to as a two-dimensional sensor) can advantageously achieve detection of two adjustment directions via a single target unit cooperating with the sensor unit (preferably a single sensor unit). As an advantage, lower manufacturing and assembly costs and a smaller size can be achieved.

[0013] Another advantage of the integrated two-dimensional sensor according to the present invention is that it can improve functionality and operational reliability while having a lower cost compared to two separate sensors and target units in the prior art.

[0014] Preferably, the target unit can be configured to extend planarly in both adjustment directions. At least the measuring portion can extend planarly in a measuring plane parallel to both the longitudinal and vertical directions. In this case, each point or defined surface portion of the measuring plane within the measuring portion can preferably be associated with a clearly defined measurement quantity. One advantage is that the surface of the measuring portion—which represents a measuring surface that can be used to determine the position in both adjustment directions—can be adapted to different designs and types of steering columns with minimal construction work in terms of its dimensions and the traces of the measurement quantities.

[0015] It may be advantageous to construct the target unit as a single component. As an advantageous improvement, the target unit can be constructed as a single piece. Therefore, production and installation can be simplified. Furthermore, the required installation space and weight can be advantageously reduced.

[0016] Preferably, the sensor unit can be configured to sense and detect the sensor target, and the target unit has a target element that has locally varying magnetic properties. The target unit can be constructed as a target element, or it can have a target element having a variable permeability on its measuring surface as a local measurement. For this purpose, the sensor unit can include an inductive sensor. It induces a local magnetic field in the target element and, as a local measurement, detects the change in magnetic flux through the target element, which is determined by the two-dimensionally varying permeability in the measuring surface. In this way, a two-dimensional measurement representing the position in two adjustment directions can be generated by the local measurement of the magnetic flux.

[0017] Preferably, the target unit or at least the target element may be made of a metallic material, such as iron or other ferromagnetic or ferrimagnetic materials, such as ferrite or ferrite embedded in a plastic matrix. It is conceivable and possible to configure the target element or target unit as a whole by means of, for example, a metal plate portion made of steel, a formed metal plate part, a molded part, etc. Alternatively, the target element may be provided with, for example, a thermoplastic material filled with a magnetic material, preferably as a plastic injection molded part. In any case, it is advantageous that the inductive measurement is non-contact and relatively robust and insensitive to interference, and that the target element can be set effortlessly.

[0018] In the above embodiments, it may be advantageous for the target element to have perforations and / or thickness-changing portions that vary across and are perpendicular to the surface area of ​​the target element. Local magnetic properties can be predetermined in a defined manner by means of the varying material thickness; for example, the varying material thickness can be formed in the measuring portion in a partially or continuously increasing manner along two adjustment directions, and can be additional or alternative perforations in the form of openings.

[0019] For example, a shaped sheet metal part made of steel may have patterns of perforation, material thinning, and / or material thickening, configured to measure the properties of the surface. Preferably, such a target element may be configured as a component or a single piece. In either case, low manufacturing costs and robust structures can be achieved.

[0020] The sensor unit can be configured to perform capacitance measurement on a target unit with a locally varying capacitance on its surface, and the target unit can have a locally varying capacitance. The sensor can be configured as a capacitance sensor, and the target unit can have a dielectric material at least in the measurement portion. This capacitance measurement method is based on a localized change in the internally coupled electric field of the target element, which can be detected simply and non-contactly by means of capacitance measurement. It is also robust and can be implemented effortlessly.

[0021] As an alternative, the sensor unit can be configured to perform a transmissive cross-sectional measurement of one of the cross-sectional measurements of a locally varying cross-section on the surface of the target unit, and the target unit has a locally varying transmissive cross-sectional measurement. By means of transmissive cross-sectional measurement, the local permeability of the measured portion can be used as the measurement quantity. For example, the target element may have a thickness that increases along two adjustment directions on the measured surface. To detect the local cross-section, methods such as optical measurement, ultrasonic measurement, etc., can be used, which can detect locally varying dimensions and / or material changes, etc.

[0022] Preferably, the position detection device is configured to have an electronic control unit. The control unit can be connected to the sensor unit for analyzing measurement signals and outputting control signals, such as those for controlling an electric adjustment actuator for adjusting the steering column.

[0023] Preferably, a motorized adjustment actuator is provided for adjusting the components. Preferably, one adjustment actuator is provided for each adjustment direction, and thus at least two adjustment actuators are provided. These adjustment actuators may have spindle drives, for example, in a manner known per se, each driven by an electric motor. In each case, the adjustment actuator is integrated between two adjustable components of the steering column, for example, integrated between a setting unit and a housing unit for longitudinal adjustment in the longitudinal direction, and integrated between a housing unit and a support unit for height adjustment in the height direction. Such adjustment actuators are known in themselves and can be reliably and flexibly adapted.

[0024] The components may include a setting unit, a housing unit, and a support unit. The setting unit, to which a steering handle is attached, is preferably adjustable relative to the housing unit in a longitudinal direction, forming a first adjustment direction, and the housing unit is preferably adjustable relative to the support unit in a height direction, forming a second adjustment direction transverse to the longitudinal direction. The position detection device according to the invention can be operatively arranged between the support unit and the setting unit, which can be adjusted two-dimensionally relative to the support unit in the aforementioned two adjustment directions. With the aid of the invention, in each case, complete two-dimensional position detection can be achieved by means of a single sensor and target unit, in each case, the single sensor and target unit being connected to the setting unit and the support unit, or vice versa.

[0025] The sensor can be an absolute sensor and / or a relative sensor. An absolute sensor can be implemented using the aforementioned inductive measurement methods and other measurement methods, where a unique absolute measurement value is assigned to each two-dimensional adjustment position. The advantage of this is that no calibration is required at startup. However, alternatively, a relative sensor, such as an incremental transducer, can also be used, where an incremental pattern, for example, changing on the measurement surface of the measurement section, is evaluated as the measured quantity. However, in this type of measurement method, calibration is typically required at startup.

[0026] Advantageous embodiments may provide a sensor unit having at least two sensor elements. In this case, according to the invention, each of these sensor elements is configured to detect a local measurement. By comparing the measurements supplied by two or more sensor elements, measurement accuracy can be improved, and redundant configuration of the position detection device can be achieved effortlessly.

[0027] The steering column can be configured as a conventional steering column, where the steering handle (e.g., a steering wheel) has a mechanical connection to the wheel to be steered. The use of this invention is particularly advantageous in the case of a steering column with steer-by-wire. In a steering system with steer-by-wire, the actuation of a steering input device—which is not mechanically connected to the wheel to be steered, for example, the steering shaft rotates by means of a steering wheel—is detected by means of electronic sensors and converted into an electrical control signal for controlling the electric steering actuator, resulting in the steering angle of the steerable wheel. Steering-by-wire systems can be preferably used in autonomous vehicles, where, during autonomous driving operation, the steering column is automatically adjusted to a retracted position outside the operating position. In this case, the position detection device according to the invention is particularly suitable for position detection in situations where a relatively large adjustment path occurs.

[0028] The invention also includes a method for operating the aforementioned steering column, the steering column having two components adjustable relative to each other in two non-parallel adjustment directions and a position detection device, the position detection device having a sensor connected to one component and including at least one sensor unit, and a sensor target connected to the other component and including at least one target unit, the sensor being configured to detect the relative position of the sensor target in the two adjustment directions, the detection device according to the invention being configured such that the target unit has a measuring portion extending in the two adjustment directions, the measuring portion having a local measurement quantity varying in each of the two adjustment directions, the local measurement quantity being detected by the sensor unit as a two-dimensional position measurement value.

[0029] By means of the method according to the invention, the functions explained above in conjunction with the steering column can be implemented in an advantageous manner, and these functions can represent all the methodological features within the scope of the invention. In this case, the advantage is that two-dimensional measurements can be obtained by means of a single target unit, which allows for simplified adjustment control. Attached Figure Description

[0030] Advantageous embodiments of the invention will now be explained in more detail with reference to the accompanying drawings, wherein in particular:

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

[0032] Figure 2 Another 3D diagram shows the results based on Figure 1 The steering column,

[0033] Figure 3 It shows according to Figure 1 and Figure 2 Side view of the steering column.

[0034] Figure 4 Showing from Figure 3 A magnified view of the details.

[0035] Figure 5 The invention is illustrated in a separate schematic diagram. Figures 1 to 4 The target element of the steering column. Detailed Implementation

[0036] In different accompanying drawings, the same parts are always given the same reference numerals, and therefore are usually specified or mentioned only once in each case.

[0037] Figure 1 A steering column 1 according to the invention is shown, which is part of the steering system of a motor vehicle not shown herein.

[0038] The steering column 1 includes a housing unit 2, in which a steering spindle 3 is mounted so as to be rotatable about a longitudinal axis L. The steering wheel 32 is fastened to a fastening portion 31 at its rear end portion facing the driver's position relative to the direction of travel.

[0039] like Figure 1 As shown, the steering column 1 can be constructed as a conventional steering column, wherein the steering spindle 3 is mechanically connected to the steering wheel via an intermediate shaft 33. Alternatively, the steering column 1 can be constructed as a steer-by-wire steering column, wherein the steering spindle 3 is not mechanically connected to the wheel to be steered and protrudes only at the rear on the driver's side for attaching the steering wheel 32. In this case, the intermediate shaft 33 is absent.

[0040] The housing unit 2 is held in the support unit 4, which can be attached to the vehicle body. For this purpose, the support unit 4 may have a fastening device 41, such as a fastening hole.

[0041] The steering wheel 32 is adjustable relative to the support unit 4, which is fixed to the vehicle body in the installed state, along the longitudinal direction given by the longitudinal axis L, as indicated by the double arrows. For height adjustment, the steering wheel 32 can be adjusted upward or downward relative to the support unit 4 in the height direction H transverse to the longitudinal axis L, also as indicated by the double arrows.

[0042] The longitudinal axis L defines the first adjustment direction, and the height direction H defines the second adjustment direction; these two directions together are referred to as the two adjustment directions.

[0043] Figure 2 The steering column 1 is shown in an enlarged perspective view with a side tilt.

[0044] The steering spindle 3 is rotatably mounted in the inner housing 21 about the longitudinal axis L. For longitudinal adjustment, the inner housing 21 is telescopingly accommodated in the outer housing 22 of the housing unit 2 in the direction of the longitudinal axis L.

[0045] For height adjustment, housing unit 2, specifically housing 22, is mounted such that it can pivot about a pivot axis 42, which is transverse to the longitudinal axis L and horizontally located in a forward region near the vehicle body relative to the direction of travel. By pivoting about this pivot axis 42, the steering wheel 32, attached to the steering spindle 3 and located at the rear end of the steering wheel on the driver's side away from the vehicle body, can be adjusted in the height direction H.

[0046] For motorized longitudinal adjustment, a first adjustment driver 5 is provided, which can be configured as a spindle driver, for example in a manner known per se, and is operatively inserted between the inner housing 21 and the outer housing 22.

[0047] For the purpose of adjusting the height for motorization, a second adjustment driver 6 is provided. The second adjustment driver 6 can be configured as a spindle driver in a manner known per se and is operatively inserted between the housing unit 2 and the support unit 4.

[0048] Figure 4 A side view of the steering column 1 transverse to the longitudinal axis L is shown.

[0049] exist Figure 4 The figure shown Figure 3 The position detection device 7 according to the invention, shown in the details at an enlarged scale, in the example shown includes a target unit having a single target element 71, which interacts with a sensor unit including a sensor element 72, the sensor element 72 in... Figure 4 The target element 71 is shown in dashed lines. In this embodiment, the target element 71 forms the target unit according to the present invention.

[0050] The target element 71 is fixed to the inner housing 21 via a connecting device—here, an elongated fixing element 73 in the exit area of ​​the steering spindle 3. The target element 71 is displaceable relative to the outer housing 22 in the longitudinal direction, for example, by being movably guided on the outer housing 22 by a linear guide or the like.

[0051] In the case of longitudinal adjustment, the target element 71 moves accordingly relative to the support unit 4 in the adjustment direction given by the longitudinal axis L, that is, it moves forward or backward relative to the support unit 4 in the first adjustment direction, such as... Figure 4 As shown by the double arrows in the image.

[0052] With height adjustment, the target element 71, together with the housing unit 2, moves upward or downward relative to the support unit 4 in the height direction H, such as... Figure 4 As shown by the double arrows in the image.

[0053] The sensor element 72 is fixed to the support unit 4 in a position relative to the housing unit 2, for example, fixed to the side wall 43 of the support unit 4. Therefore, the target element 71 moves relative to the sensor element 72 parallel to the measurement plane (the so-called LH measurement plane) traversed by the longitudinal axis L and the height direction. This relative movement can occur accordingly in two dimensions in the two adjustment directions defined by the longitudinal axis L and the vertical direction H.

[0054] According to the invention, the target element 71 and the sensor element 72 together are in Figure 5 The sensor element 72 is shown schematically again with dashed lines, and is represented separately in the middle. It can be clearly seen how the target element 71 extends in a planar manner parallel to the LH measurement plane.

[0055] The target element 71 can preferably be constructed as a single piece of a metallic material, such as a cold-formed part made of steel or the like. The target element 71 can also have a ferromagnetic or ferrimagnetic material, which can be embedded in, for example, a plastic matrix. The target element 71 can then be constructed, for example, preferably as a one-piece plastic injection-molded part or a part having such a component.

[0056] In order to form a measurement quantity that varies on the LH measurement plane according to the present invention, the target element 71 may have, for example, one or more perforations 710 in the measurement portion, and additionally or alternatively, a thickness-changing portion 711, such as local thickening and / or thinning, for example, a groove-shaped recess or indentation, and / or a bead-shaped or web-shaped protrusion, the measurement portion extending in a planar manner and may extend on part or the entire surface of the target element 71.

[0057] The perforation 710 or the thickness variation section 711 generates a local permeability that varies in the two adjustment directions L and H. This can be locally measured by means of a sensor element 72 having at least one sensing sensor, and is output to the control unit as a two-dimensional measurement value.

[0058] Other two-dimensional measurement methods, not explicitly described herein, can also be used to achieve the measurement between the planar target element 71 and the corresponding sensor element 72, such as local capacitance or optical measurement in the region, measurement by means of devices such as ultrasound, or other position-sensitive measurement methods.

[0059] List of reference numerals in the attached diagram:

[0060] 1 Steering column

[0061] 2 shell units

[0062] 21 Inner shell

[0063] 22 outer shell

[0064] 3 steering spindles

[0065] 31 Fastening parts

[0066] 32 steering wheel

[0067] 4 support units

[0068] 41 Fastening device

[0069] 42 Pivot axis

[0070] 43 sidewalls

[0071] 5 Adjustment Driver

[0072] 6 Adjustable Driver

[0073] 7 Position Detection Device

[0074] 71 Target Components (=Target Units)

[0075] 710 perforation

[0076] 711 Thickness Change Section

[0077] 72 sensor elements

[0078] 73 Fixed Components

[0079] L longitudinal axis

[0080] H-height direction

Claims

1. A steering column (1) for a motor vehicle, the steering column (1) having a position detection device (7) and two components (3, 4) adjustable relative to each other in two non-parallel adjustment directions (L, H), the position detection device (7) having a sensor connected to one component (3) and including at least one sensor unit (72), and a sensor target connected to the other component (4) and including at least one target unit (71), the sensor being configured to detect the relative position of the sensor target. Its features are, The target unit (71) has a measuring portion extending along the two adjustment directions (L, H), the measuring portion having a local measurement quantity that varies in each of the two adjustment directions (L, H), the local measurement quantity being locally detectable by the sensor unit (72); the sensor unit (72) is configured to sense and detect the sensor target, and the target unit (71) has a target element (71) having locally varying magnetic properties; the target element (71) has a perforation (710) and / or a thickness variation portion (711), the perforation (710) and / or the thickness variation portion (711) varying within the surface range of the target element (71) and perpendicular to the surface range of the target element (71).

2. The steering column according to claim 1, characterized in that, The target unit (71) extends in a planar manner in the two adjustment directions (L, H).

3. The steering column according to any one of claims 1-2, characterized in that, The target unit (71) is constructed as a component.

4. The steering column according to any one of claims 1-2, characterized in that, The target unit (71) is constructed as one piece.

5. The steering column according to any one of claims 1-2, characterized in that, The sensor unit (72) is configured to perform capacitance measurement on the target unit, which has a locally varying capacitance measurement on the surface, and the target unit has a locally varying capacitance measurement.

6. The steering column according to any one of claims 1-2, characterized in that, The sensor unit (72) is configured to perform a transmissive cross-sectional measurement on one of the local cross-sectional measurements of the target unit that varies on the surface, and the target unit has a locally varying transmissive cross-sectional measurement.

7. The steering column according to any one of claims 1-2, characterized in that, The position detection device (7) has an electronic control unit.

8. The steering column according to any one of claims 1-2, characterized in that, An automated adjustment driver (5, 6) is provided for adjusting the component.

9. The steering column according to any one of claims 1-2, characterized in that, The components include a setting unit (3, 21), a housing unit (2), and a support unit (4).

10. The steering column according to any one of claims 1-2, characterized in that, The sensor has an absolute value sensor and / or a relative value sensor.

11. The steering column according to any one of claims 1-2, characterized in that, The steering column is configured as a steer-by-wire type steering column.

12. A method for operating a steering column according to any one of claims 1 to 11, the steering column having a position detection device (7) and two components (3, 4) adjustable relative to each other in two non-parallel adjustment directions (L, H), the position detection device (7) having a sensor connected to one component (3) and including at least one sensor unit (72), and a sensor target connected to the other component and including at least one target unit (71), the sensor being configured to detect the relative position of the sensor target in the two adjustment directions (L, H). Its features are, The target unit (71) has a measuring portion extending along the two adjustment directions (L, H), the measuring portion having a local measurement quantity that varies in each of the two adjustment directions (L, H), the local measurement quantity being detected by the sensor unit (72) as a two-dimensional position measurement value.

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