Steering column for a motor vehicle

Abstract

Steering column (1) for a motor vehicle, comprising an outer casing (4) in which an actuating unit (3) with a steering spindle (31) rotatably mounted about a longitudinal axis (L) is accommodated and which is held by a support unit (2), wherein at least one motorized adjustment drive (5, 6) is supported on the outer casing (4), which has an adjustable transmission element (54, 64) which engages the actuating unit (3) or the support unit (2), and wherein a stop device is provided for limiting the adjustment path of the actuating unit (3) and / or the support unit (2) relative to the outer casing (4), wherein the stop device has at least one stop element (41, 42, 42, 44) formed on the outer casing (4), against which the transmission element (54, 64) can be struck, wherein the transmission element (64) is pivotally mounted on the outer casing (4), characterized by that the outer casing (4) comprises a cast part, and a stop element (41, 42, 42, 44) is formed integrally with the outer casing (4).

Description

State of the art

[0001] The invention relates to a steering column for a motor vehicle, comprising an outer casing in which an actuating unit with a steering spindle mounted so as to be rotatable about a longitudinal axis is accommodated and which is held by a support unit, wherein at least one motorized adjustment drive is supported on the outer casing, which has an adjustable transmission element which engages the actuating unit or the support unit, and wherein a stop device is provided for limiting the adjustment path of the actuating unit and / or the support unit relative to the outer casing, wherein the stop device has at least one stop element formed on the outer casing, against which the transmission element can be struck, wherein the transmission element is pivotally mounted on the outer casing.

[0002] A motor-adjustable steering column has an actuating unit in which a steering spindle is mounted for rotation about its longitudinal axis. At the rear end of the spindle, facing the driver's position and in relation to the direction of travel, a steering wheel is mounted for inputting manual steering commands. The actuating unit is housed in the outer casing of a casing unit, also known as a guide box, outer casing tube, or box-type rocker arm. This, in turn, is held by the support unit that can be connected to the body of the vehicle.

[0003] To adjust the steering wheel position, longitudinal adjustment can be achieved by telescopically adjusting the actuating unit in the longitudinal direction relative to the outer casing. Additionally or alternatively, height adjustment can be achieved by vertically adjusting the outer casing relative to the support unit.

[0004] To adjust the steering column, a motorized adjustment drive can be provided for each adjustment direction, preferably for both adjustment directions, as described, for example, in EP 3 341 262 B1. For longitudinal adjustment, an adjustment drive designed as a motorized spindle drive can be integrated between the outer casing and the actuating unit. This adjustment drive is supported by its drive unit on the outer casing, and a threaded spindle or spindle nut that is motor-adjustable relative to it in the longitudinal direction is connected to the actuating unit via a transmission element. For height adjustment, an adjustment drive can be provided which also has a drive unit supported on the outer casing and engages the support unit via an actuating lever hinged to the outer casing.

[0005] To define the adjustment range, the known steering column features a stop device that limits the adjustment range of the actuator relative to the outer casing in the longitudinal direction and, additionally or alternatively, limits the adjustment range of the outer casing relative to the support unit in the vertical direction. For this purpose, a stop device is integrated into the adjustment drive to limit the possible displacement of the transmission element relative to the drive unit, for example, by causing the threaded spindle to strike the spindle nut.

[0006] While this allows for limiting the adjustment range, it is possible that dimensional tolerances in the mounting of the adjustment drive and the integrated stop limiter may add up to unfavorable results. Furthermore, the integrated stop limiter may result in a more complex design of the adjustment drive.

[0007] A steering column of the type mentioned above is described in DE 10 2021 003 660 A1, or in similar versions in DE 10 2018 202 157 A1 or DE 10 2021 212 039 A1.

[0008] In view of the problems explained above, it is an object of the present invention to enable an improved limitation of the adjustment path. Description of the invention

[0009] This object is achieved according to the invention by the steering system having the features of claim 1. Advantageous further developments emerge from the subclaims.

[0010] In a steering column for a motor vehicle, comprising an outer casing in which an actuating unit with a steering spindle mounted so as to be rotatable about a longitudinal axis is accommodated and which is held by a support unit, wherein at least one motorized adjustment drive is supported on the outer casing, which motorized adjustment drive has an adjustable transmission element which engages the actuating unit or the support unit, and wherein a stop device is provided for limiting the adjustment path of the actuating unit and / or the support unit relative to the outer casing, wherein the stop device has at least one stop element formed on the outer casing, against which the transmission element can be struck, wherein the transmission element is pivotally mounted on the outer casing, the invention provides that the outer casing has a cast part, and a stop element is formed integrally with the outer casing.

[0011] For longitudinal adjustment, the adjustment drive is operatively arranged between the outer casing and the adjustment unit, and is coupled to the adjustment unit via the transmission element, allowing the adjustment relative to the outer casing. For vertical adjustment, the adjustment drive is operatively arranged between the outer casing and the support unit, and is coupled to the support unit via the transmission element, allowing the outer casing to be adjusted relative to the support unit.

[0012] The transmission element can strike against a stop element of the outer casing, i.e., come into direct, positive mechanical contact with it. Because the stop element is preferably coupled in the adjustment direction to the actuating or supporting unit, which is adjustable relative to the support unit, the adjustment movement is stopped upon reaching the stop element. An advantage of this arrangement is that only the dimensional tolerances between the transmission element and the support unit can influence the adjustment path, whereas in the prior art, the tolerances of the stop integrated into the adjustment drive must also be taken into account. This allows the dimensional accuracy of the limitation of the adjustment path to be increased with little effort.

[0013] One advantage is that it's not necessary to integrate a stop device into the adjustment drive, which eliminates the need for machining a threaded spindle, for example. Accordingly, the adjustment drive can be designed more simply, reducing manufacturing costs.

[0014] According to the invention, a stop element is formed integrally with the outer casing. This allows one or preferably several stop elements to be integrated with the outer casing. This is advantageous in terms of reduced manufacturing and assembly costs.

[0015] The outer shell is provided with a cast part. The outer shell can be formed partially or entirely as a cast part. A metal injection-molded part, for example made of an aluminum or magnesium alloy, can be used as the cast part. This can have a complex shape and, for example, have integrated holding, bearing, and guide elements and the like, for example for telescopically guiding the actuating unit or for movable mounting on the support unit. One or more stop elements can preferably be integrally formed on the outer shell using a casting process. This enables efficient production. Alternatively, one or more stop elements can be formed from a different material and connected to the cast part.

[0016] A preferred embodiment provides that two stop elements are assigned to one transmission element. The two, i.e. the two stop elements, form a pair of opposing end stops between which the transmission element can be moved back and forth during adjustment, and which accordingly limit the possible movement path of the transmission element and thus the maximum adjustment path of the actuating unit or the support unit relative to the outer casing in the two opposite adjustment directions. An advantage of this arrangement is that the two stop elements of a pair can be positioned flexibly and with little design and manufacturing effort relative to one another and to the transmission element on the outer casing. The permissible adjustment path can be easily adjusted by changing the distance between the stop elements.A further advantage is that a standardized adjustment drive can be used without structural changes on different types of steering columns, which differ in the arrangement and spacing of the stop elements on the outer casing to achieve different adjustment paths.

[0017] Preferably, it is possible to provide at least one stop element that interacts with the actuating unit, and at least one stop element that interacts with the support unit. Preferably, two stop elements are provided for each of the transmission elements coupled to the actuating unit and the transmission element coupled to the support unit. This limits the adjustment path of the longitudinal adjustment of the actuating unit relative to the outer casing in the longitudinal direction, and limits the adjustment path of the height adjustment of the outer casing relative to the support unit in the height direction. The advantage is that the adjustment paths in both adjustment directions can be flexibly specified with little effort through the arrangement of the stop elements.

[0018] It is possible for the stop element to have a projection protruding from the outer casing. The projection is positioned and configured to have a stop or contact surface arranged transversely in the movement path of the transmission element.

[0019] The transmission element, which moves relative to the outer casing during adjustment, can mechanically strike the projection. This allows for a simple, low-effort, end stop to be implemented.

[0020] It is possible for the outer shell to comprise a formed sheet metal part. Such a formed sheet metal part can be provided, for example, as a preferably cold-formed part, preferably by pressing, punching, bending, or the like from sheet steel. The outer shell can comprise a one-piece formed sheet metal part or be joined from several formed sheet metal parts, for example by welding or other joining methods. The formed sheet metal part can be complexly shaped and, for example, comprise holding, bearing, and guide elements and the like, for example for telescopically guiding the actuating unit or for movable mounting on the support unit. The stop elements according to the invention can preferably be formed by forming the sheet metal part, for example by local bending, pressing, or the like. This enables efficient production.

[0021] Additionally or alternatively, the outer shell may comprise a composite material. The outer shell may, for example, be formed entirely or at least partially from a composite material, preferably from a fiber composite material such as a glass fiber reinforced plastic (GRP) or a carbon fiber reinforced plastic (CFRP). One or more stop elements may be formed from the composite material and integrally molded, or formed from a different material and bonded to the composite material. In this way, a highly resilient and particularly lightweight design can be realized.

[0022] It is advantageous that the adjustment drive has a spindle drive.

[0023] It is possible for the spindle drive to have a motor drive unit and a spindle nut or threaded spindle that is adjustable relative thereto and is connected to a transmission element. A spindle drive comprises a threaded spindle that engages a spindle nut. Because the threaded spindle and the spindle nut can be driven to rotate relative to one another about the spindle axis, they can be moved translationally towards or away from one another in the direction of the spindle axis, depending on the direction of rotation. In one embodiment, the so-called rotary spindle drive, the threaded spindle can be driven to rotate about its spindle axis by a motor drive unit, which can preferably be fixedly connected to the support unit, and engages the spindle nut, which is fixedly attached to a transmission element with respect to rotation about the spindle axis. Axial, i.e.In the direction of the spindle axis, the threaded spindle is supported on the support unit, and the spindle nut on the transmission element, so that a rotary drive of the threaded spindle causes a translational adjustment of the transmission element relative to the support unit. In an alternative embodiment, referred to as a plunger spindle drive, the threaded spindle is non-rotatably connected to the transmission element with respect to rotation about the spindle axis and is axially supported, and the spindle nut can be driven in rotation via the drive unit supported on the support unit. Such spindle drives are robust and reliable. The stop elements arranged according to the invention allow the spindle drives to be simpler and lighter in construction.

[0024] It can be provided that the transmission element is translationally displaceable relative to the outer casing. The transmission element can comprise, for example, a spindle nut or a threaded spindle of a spindle drive, and / or a coupling element connected thereto, which can be translationally displaced by the spindle drive, for example, linearly in the direction of the spindle axis. Accordingly, the linear movement path can be limited by at least one stop element on the outer casing.

[0025] Alternatively, it is possible for the transmission element to be pivotably mounted on the outer casing. The transmission element can have an adjusting lever mounted on the outer casing so as to be rotatable about a lever axis. This can be designed, for example, as a two-armed lever, one lever arm of which is acted upon by an adjustment drive designed as a linear drive, for example a spindle drive, and the other lever arm of which is articulated to the adjusting unit or support unit that is adjustable relative to the outer casing. The adjusting lever can, for example, be mounted externally on the outer casing so as to be rotatable about its lever axis, and preferably a pair of two stop elements can be arranged on the outer casing so as to project outwards such that the adjusting lever can be abutted against it to limit the possible angle of rotation.

[0026] The transmission element can be guided in a guide device on the outer casing. For example, a linear guide can be implemented. The transmission element can be guided along a predetermined path relative to the outer casing, for example, on a guide profile. The transmission element can be slidably mounted thereon, for example, in a linear plain bearing. Alternatively, a rotary guide can be implemented, for example, by rotatably mounting the transmission element relative to the outer casing, for example, in a pivot bearing. The guide device can preferably extend between the stop elements. Description of the drawings

[0027] Advantageous embodiments of the invention are explained in more detail below with reference to the drawings. In detail: Fig. 1 a steering column according to the invention in a schematic perspective view, Fig. 2 the steering column according to Fig. 1 in another perspective view. Embodiments of the invention

[0028] In the various figures, identical parts are always provided with the same reference symbols and are therefore usually named or mentioned only once.

[0029] Fig. 1 shows a steering column 1 according to the invention as a whole in a perspective view diagonally from the left to the front in the direction of travel, and Fig. 2 a view from below, with the direction of travel pointing to the right.

[0030] The steering column 1 comprises a support unit 2 which can be fixed to a vehicle body not shown here.

[0031] The support unit holds an actuating unit 3 in which a steering spindle 31 is mounted so as to be rotatable about the longitudinal axis L. In the rear end region, the steering spindle 31 has an attachment section 32 to which a steering wheel (not shown here) can be mounted.

[0032] The actuating unit 3 has an inner casing 33 in which the steering spindle 31 is rotatably mounted. The inner casing 33 extends telescopically into an outer casing 4 in the longitudinal direction defined by the longitudinal axis L. By inserting or withdrawing the actuating unit 3, a longitudinal adjustment of the steering wheel position is possible, as indicated by the double arrow.

[0033] The outer casing 4 is pivotably mounted in its front region about a height adjustment axis 21 lying transversely to the longitudinal axis L, so that a height adjustment of the steering spindle 31 in the height direction H is possible, as indicated by the double arrow.

[0034] For longitudinal adjustment, a first adjustment drive 5 is provided, which is designed as a spindle drive and has a motor drive unit 51 mounted on the outer shell 4 and supported in the longitudinal direction. This motor drive unit 51 rotates a threaded spindle 52, arranged with its spindle axis parallel to the longitudinal axis L. The threaded spindle 52 engages a spindle nut 53, which is fixed to a transmission element 54 in a rotationally fixed manner with respect to the spindle axis and supported in the longitudinal direction. The transmission element 54 is connected to the adjustment unit 3, specifically to the inner shell 33.

[0035] A stop device according to the invention has two stop elements 41 and 42 attached to the outer casing 4. They are arranged in the movement path in the adjustment direction of the adjustment drive 5, i.e., in the longitudinal direction, in front of and behind the transmission element 54, such that the latter can strike against them. Thus, the stop elements 41 and 42 form end stops for limiting the adjustment path of the adjustment unit 3 relative to the support unit 2.

[0036] The transmission element 54 can be guided in the adjustment direction in a guide device on the support unit 2, for example, on a guide profile 55. The transmission element 54 is slidably mounted thereon, for example, in a linear plain bearing. The guide device can extend between the stop elements 41 and 42.

[0037] For height adjustment, a second adjustment drive 6 is provided, which also has a spindle drive, with a motor drive unit 61 fixed to the outer casing 4. A threaded spindle 62, which engages a spindle nut 63, can be driven in rotation by the drive unit 61.

[0038] The spindle nut 63 is secured against rotation about the spindle axis by being articulated to a transmission element designed as an adjusting lever 64. This adjusting lever 64 is designed as a two-armed lever mounted on the outer casing 4 so as to be rotatable about a rotation axis 65. The adjustment drive 6 engages one lever arm, and the other lever arm is articulated to the support unit 2.

[0039] By actuating the adjustment drive 6, the adjusting lever 64 can be pivoted, ie rotated, about the rotation axis 65, whereby the outer casing 4 is adjusted in the height direction H relative to the support unit 2.

[0040] Stop elements 43 and 44 are attached to the outer casing 4, which protrude outward into the movement path of the pivot lever 64 such that the lever can strike against them during adjustment. In other words, the stop elements 43 and 44 form end stops that limit the adjustment path of the outer casing 4 relative to the support unit 2.

[0041] The rotatable mounting around the rotation axis 65 forms a guide device for the adjusting lever 64, namely a rotation guide for this transmission element.

[0042] The support unit 2 can comprise a cast part, for example, a metal die-cast part made of an aluminum or magnesium alloy. The stop elements 41 and 42, as well as 43 and 44, can preferably be integrally formed on the cast part. List of reference symbols 1 steering column 2 carrying unit 21 Height adjustment axis 3 Actuator 31 Steering spindle 32 Attachment section 33 inner jacket 4 Outer jacket 41, 42 Stop elements 43, 44 Stop elements 5, 6 Adjustment drive 51, 61 drive unit 52, 62 threaded spindle 53, 63 spindle nut 54, 64 transmission element 55 Leadership profile 65 axis of rotation L Longitudinal axis H Altitude direction

Claims

[1] Steering column (1) for a motor vehicle, comprising an outer casing (4) in which an actuating unit (3) with a steering spindle (31) rotatably mounted about a longitudinal axis (L) is accommodated and which is held by a support unit (2), wherein at least one motorized adjustment drive (5, 6) is supported on the outer casing (4), which has an adjustable transmission element (54, 64) which engages the actuating unit (3) or the support unit (2), and wherein a stop device is provided for limiting the adjustment path of the actuating unit (3) and / or the support unit (2) relative to the outer casing (4), wherein the stop device has at least one stop element (41, 42, 42, 44) formed on the outer casing (4), against which the transmission element (54, 64) can be struck, wherein the transmission element (64) is pivotally mounted on the outer casing (4), characterized by , that the outer casing (4) comprises a cast part, and a stop element (41, 42, 42, 44) is formed integrally with the outer casing (4). [2] Steering column according to claim 1, characterized by that two stop elements (41, 42, 42, 44) are assigned to a transmission element (54, 64). [3] Steering column according to one of the preceding claims, characterized by that at least one stop element (41, 42) cooperating with the actuating unit (3) is provided, and at least one stop element (43, 44) cooperating with the support unit (2) is provided. [4] Steering column according to one of the preceding claims, characterized by that the stop element (41, 42, 42, 44) has a projection protruding from the outer casing (4). [5] Steering column according to one of the preceding claims, characterized by that the outer shell (4) has a sheet metal part. [6] Steering column according to one of the preceding claims, characterized bythat the outer shell (4) comprises a composite material. [7] Steering column according to one of the preceding claims, characterized by that the adjustment drive (5, 6) has a spindle drive. [8] Steering column according to claim 7, characterized by that the spindle drive has a motor drive unit (51, 61) and a spindle nut (53, 63) or threaded spindle (52, 62) which is adjustable relative thereto and is connected to a transmission element (54, 64). [9] Steering column according to one of the preceding claims, characterized by that the transmission element (54) is translationally displaceable relative to the outer casing (4). [10] Steering column according to one of the preceding claims, characterized by that the transmission element (54, 64) is guided in a guide device (55, 65) on the outer casing (4).

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