Steering column assembly for a motor vehicle

Abstract

A steering column assembly for a motor vehicle, comprising a steering column (12) having a longitudinal axis (A), a holding element (14) for the adjustable mounting of the steering column (12), a gear (16) mounted on the holding element (14) for rotation about a rotational axis (B), and a coupling mechanism (18) for releasing or blocking rotation of the gear (16) about the rotational axis (B), said coupling mechanism being movable between a release position and a blocking position, wherein a toothing (20) is provided on the steering column (12) and engages with the gear (16), so that the gear (16) rotates about the rotational axis (B) upon adjustment of the steering column (12), and the coupling mechanism (18) has a coupling body (32) which, in the blocking position of the coupling mechanism (18), is positively and / or non-positively coupled to the gear (16). and in the release position of the clutch mechanism (18) is decoupled from the gear (16),characterized in that the coupling body (32) is a pawl.,

Description

[0001] The invention relates to a steering column assembly for a motor vehicle having the features of the preamble of claim 1.

[0002] Such a steering column assembly is known from DE 10 2012 209 283 A1 or US 2008 / 0 143 092 A1.

[0003] From DE 10 2014 202 762 A1 a steering column assembly with a clutch mechanism is known which uses a magnetorheological fluid.

[0004] Many vehicles currently feature a steering column that is adjustable for length and / or height to accommodate comfort features such as individual steering wheel position adjustment by the driver. This mounting is typically achieved via a retaining element that either allows adjustment of the steering column or locks it via a clamping mechanism. This clamping mechanism can be manually operated via a lever, allowing the driver to adjust the steering column to their individual preferences and then lock it in the desired position for driving.

[0005] After releasing the clamping mechanism, the steering column is freely movable, at least within certain limits. This creates a degree of free play that allows undefined movements of the steering column and any levers, trim units, or switch units (steering column switches) and can lead to individual components of the steering column assembly becoming jammed or caught. Therefore, smooth and effortless adjustment of the steering column cannot be guaranteed.

[0006] The object of the invention is to provide a steering column assembly in which the steering column does not have an undefined movement play even in the case of a steering column adjustment, but rather ensures a smooth individual adjustment of the steering wheel, which the driver perceives as gentle and supple.

[0007] According to the invention, this object is achieved by a steering column assembly for a motor vehicle having the features of claim 1 and having a steering column which has a longitudinal axis, a holding element for the adjustable mounting of the steering column, a gear which is mounted on the holding element so as to be rotatable about a rotation axis, and a coupling mechanism for releasing or blocking rotation of the gear about the rotation axis, which coupling mechanism is movable between a release position and a blocking position, wherein a toothing is provided on the steering column which engages with the gear so that the gear rotates about the rotation axis when the steering column is adjusted.Since the gear is in constant meshing engagement with the gear teeth, regardless of the release or lock position of the clutch mechanism, a permanent mechanical connection exists between the steering column and the body-mounted retaining element, which is ideally free of play or at least designed with minimal play. Accordingly, when adjusting the steering column, the steering column no longer has any free play, but is limited to mechanically predetermined, defined degrees of freedom of movement for longitudinal and / or vertical adjustment of the steering column. This results in a jam-free and smooth adjustment of the steering wheel or steering column, which the driver perceives as smooth and comfortable.

[0008] According to one embodiment of the steering column assembly, the steering column has a rack on which the gearing is formed. The gear of the steering column assembly thus forms a rack and pinion gear with the gearing of the steering column, in which an adjustment of the steering column is converted into a rotation of the gear.

[0009] In this embodiment, the steering column preferably comprises a steering column casing, with the rack being rigidly connected to the steering column casing. Based on conventional steering column assemblies, no or at most minor structural adjustments to the steering column casing are necessary, so the manufacturing process for the steering column can be largely retained and the manufacturing effort remains essentially unchanged.

[0010] The rack preferably extends in the direction of the longitudinal axis, which makes it easy to adjust the length of the steering column, but also to pivot the steering column to adjust the height of the steering wheel.

[0011] According to a further embodiment of the steering column assembly, the rotational axis of the gear extends essentially in a radial plane of the longitudinal axis of the steering column. This arrangement allows for advantageous longitudinal and vertical adjustment of the steering column with minimal design effort.

[0012] Preferably, the gearing on the steering column is helical, and the gear meshing with the gearing is a helical spur gear. As a result of these helical gearings, both longitudinal and vertical adjustment of the steering column are translated into rotation of the gear about the rotation axis. In other words, by locking the rotation of the gear about the rotation axis, both longitudinal and vertical adjustment of the steering column are reliably prevented, and the steering column is fixed in its position.

[0013] According to the invention, the clutch mechanism comprises a coupling body which, in the locked position of the clutch mechanism, is positively and / or non-positively coupled to the gearwheel and, in the released position of the clutch mechanism, is decoupled from the gearwheel. This clutch mechanism can be actuated manually, for example, to prevent rotation of the gearwheel and thus adjustment of the steering column in a locked position, and to enable individual positioning of the steering wheel by adjusting the steering column in the released position.

[0014] According to the invention, the coupling body is a pawl. To prevent rotation of the gear about the rotational axis, the pawl can, for example, positively engage with a toothing of the gear or with recesses of an axial gear extension. According to an alternative not according to the invention, the coupling body can be a friction element, wherein the friction element is pressed, for example, radially against the gear or an axial gear extension to prevent rotation of the gear about the rotational axis by frictional engagement. Furthermore, a combination of a frictional connection and a positive connection is also conceivable on the axial gear extension.

[0015] In a further embodiment of the steering column assembly, at least one spring element is provided, which acts to counteract the gear and the toothing of the steering column. In this way, any existing play in the rack and pinion mechanism formed by the gear and the toothing can be minimized or even largely eliminated with little effort. As a result of this low-play and constantly present mechanical coupling between the steering column and the body-mounted holding element, no uncontrolled, free movement of the steering column relative to the holding element is possible, even in the release position of the coupling mechanism, so that the components of the steering column assembly cannot jam or catch. The preload of the rack and pinion mechanism thus contributes to particularly smooth and effortless adjustment of the steering column.

[0016] In this embodiment, the gear is mounted on the holding element with radial play, for example, and is radially loaded against the toothing by a spring element.

[0017] Alternatively or additionally, the steering column can be mounted on the retaining element with radial play relative to its longitudinal axis and radially biased against the gear by a spring element. Due to the preload of the rack and pinion gear formed by the gear and the toothing, the play present in the rack and pinion gear is minimized with little effort.

[0018] According to yet another embodiment of the steering column assembly, an electric drive is provided for rotating the gear about its rotational axis. This drive comprises, for example, a drive pinion that meshes with the gear or an axial toothed extension of the gear. Preferably, in this case, a drive control and steering column guide means are also provided to implement a desired longitudinal and / or vertical adjustment of the steering column via the electric drive. Thus, a preferred steering wheel position previously stored by the driver can be automatically adjusted via the electric drive. Manual adjustment of the desired steering wheel position by the driver is no longer necessary.

[0019] Examples of embodiments of the invention will become apparent from the following description of a preferred embodiment with reference to the drawings, in which: Fig. 1 a schematic diagram of the steering column assembly according to the invention; and Fig. 2 a plan view of a special embodiment of the steering column assembly according to Fig. 1.

[0020] The Fig. 1 and Fig. 2 show a steering column assembly 10 for a motor vehicle, wherein the Fig. 1 schematically shows the general operating principle and in Fig. 2 a concrete technical implementation is indicated.

[0021] The steering column assembly 10 comprises a steering column 12 having a longitudinal axis A, a body-mounted holding element 14 for longitudinally and / or vertically adjustable mounting of the steering column 12, a gear 16 which is rotatably mounted on the holding element 14 about a rotation axis B, and a coupling mechanism 18 for releasing or blocking rotation of the gear 16 about the rotation axis B, which coupling mechanism is movable between a release position and a blocking position.

[0022] A linear toothing 20 is provided on the steering column 12, which is in meshing engagement with the gear 16, so that the gear 16 rotates about the rotation axis B when the steering column 12 is adjusted.

[0023] In the case of a rack and pinion steering system of the motor vehicle, the steering column 12 extends from a steering wheel to a pinion, which engages with a rack of the motor vehicle steering system. As in Fig. 2, the steering column 12 comprises, among other things, a steering shaft 22 which extends in the axial direction 24 and is mounted in a casing tube 26 of the steering column 12 so as to be rotatable about the longitudinal axis A.

[0024] According to Fig. 2, the toothing 20 provided on the steering column 12 is specifically formed on a rack 28, wherein the rack 28 is fixedly connected to the casing tube 26 of the steering column 12.

[0025] In addition, the Fig. 2 clearly shows that the rack 28 extends in the direction of the longitudinal axis A and the rotation axis B extends essentially in a radial plane of the longitudinal axis A.

[0026] Furthermore, the toothing 20 is a helical toothing and the gear 16 meshing with the linear toothing 20 is a helical spur gear or pinion. Due to these helical toothings, both a longitudinal and a vertical adjustment of the steering column 12 leads to a rotation of the gear 16 about the rotation axis B. In this case, an axial displacement with respect to the longitudinal axis A is referred to as the longitudinal adjustment of the steering column 12, and a pivoting of the steering column 12 is referred to as the vertical adjustment of the steering column 12, as it is described in the Fig. 1 and Fig. 2 is indicated by an arrow 30.

[0027] In other words, the gear 16 and the linear gearing 20 provided on the steering column 12 form a rack and pinion gear, which converts any adjustment of the steering column 12 into a rotation of the gear 16. Accordingly, by simply locking the gear rotation, steering column adjustment can be prevented, thus fixing the steering column 12 in its position.

[0028] To enable or block rotation of the gear 16 about the rotation axis B, the coupling mechanism 18 is provided, which comprises a coupling body 32 fixed to the vehicle body. This coupling body 32 is positively and / or non-positively coupled to the gear 16 in the locked position of the coupling mechanism 18 and decoupled from the gear 16 in the released position of the coupling mechanism 18.

[0029] According to Fig. 2, the coupling body 32 is a friction element which is pressed radially against an axial extension 36 of the gear 16 with respect to the rotation axis B by manual actuation of an adjusting lever 34 of the coupling mechanism 18 in order to prevent rotation of the gear 16 about the rotation axis B by means of frictional engagement.

[0030] Alternatively, it is also conceivable that the coupling body 32 is a pawl which can engage in a toothing of the gear 16 or in recesses of an axial gear extension in order to prevent rotation of the gear 16 about the rotation axis B by means of positive locking.

[0031] The adjusting lever 34 of the clutch mechanism 18 is connected to a Fig. 2, the mounting element 38 is firmly connected to a vehicle body, so that the coupling mechanism 18 can be moved between its release position and its locking position by manually actuating the actuating lever 34. In the present embodiment, the coupling mechanism 18 is actuated by pivoting the actuating lever 34, as shown in Fig. 2 is illustrated by arrows 40.

[0032] In order to minimize the play of the rack and pinion gear in the steering column assembly 10, Fig. 1 at least one spring element 42, 44 is provided, which acts on the gear 16 and the linear toothing 20 of the steering column 12 against each other.

[0033] The gear 16 can, for example, be mounted on the holding element 14 with radial play with respect to the rotation axis B and be radially loaded against the toothing 20 by the spring element 42.

[0034] Alternatively or additionally, the steering column 12 can be mounted with radial play on the holding element 14 with respect to the longitudinal axis A and perpendicular to the direction 30 of a height adjustment of the steering column 12 and can be radially loaded against the gear 16 by the spring element 44. The spring element 44 is supported on the one hand on the holding element 14 and on the other hand on the casing tube 26 of the steering column 12, wherein one end of the spring element 44 can be guided displaceably in the direction of the longitudinal axis A and / or in the direction 30 of the height adjustment in order to maintain a radial alignment of the spring force of the spring element 44 even when the steering column 12 is adjusted.

[0035] As in Fig.1 is indicated by dashed lines, according to a special embodiment of the steering column assembly 10, an electric drive 46 can additionally be provided for rotating the gear 16 about the rotation axis B. This electric drive 46, which is preferably designed as a rotary drive, has a drive pinion 48 which meshes with the gear 16 or an axial toothed extension of the gear 16.

[0036] Preferably, this embodiment also includes a drive control and steering column guide means to implement a desired longitudinal and / or vertical adjustment of the steering column 12. The electric drive 46 can then automatically adjust a desired position of the steering column 12 or the steering wheel, for example, a previously stored position. Manual adjustment of the steering column 12 by the driver is no longer necessary. The clutch mechanism 18 can be actuated either automatically via the drive control or manually by the driver.

Claims

[1] Steering column assembly for a motor vehicle, comprising a steering column (12) having a longitudinal axis (A), a holding element (14) for the adjustable mounting of the steering column (12), a gear (16) which is rotatably mounted on the holding element (14) about a rotational axis (B), and a coupling mechanism (18) for releasing or blocking rotation of the gear (16) about the rotational axis (B), which is movable between a release position and a blocking position, wherein a toothing (20) is provided on the steering column (12) which engages with the gear (16) so that the gear (16) rotates about the rotational axis (B) when the steering column (12) is adjusted, and the coupling mechanism (18) has a coupling body (32) which, in the blocking position of the coupling mechanism (18), is positively and / or non-positively connected to the gear (16). coupled and decoupled from the gear (16) in the release position of the coupling mechanism (18), characterized bythat the coupling body (32) is a pawl. [2] Steering column assembly according to claim 1, characterized by that the steering column (12) has a rack (28) on which the toothing (20) is formed. [3] Steering column assembly according to claim 2, characterized by that the steering column (12) comprises a casing tube (26) and the rack (28) is firmly connected to the casing tube (26). [4] Steering column assembly according to claim 2 or 3, characterized by that the rack (28) extends in the direction of the longitudinal axis (A). [5] Steering column assembly according to one of the preceding claims, characterized by that the axis of rotation (B) of the gear (16) extends substantially in a radial plane of the longitudinal axis (A) of the steering column (12). [6] Steering column assembly according to one of the preceding claims, characterized bythat the toothing (20) is a helical toothing and the gear (16) meshing with the toothing (20) is a helical spur gear. [7] Steering column assembly according to one of the preceding claims, characterized by that at least one spring element (42, 44) is provided which acts on the gear wheel (16) and the toothing (20) of the steering column (12) against each other. [8] Steering column assembly according to claim 7, characterized by that the gear (16) is mounted with radial play on the holding element (14) and is radially loaded against the toothing (20) by a spring element (42). [9] Steering column assembly according to claim 7 or 8, characterized by that the steering column (12) is mounted with radial play on the holding element (14) and is radially loaded against the gear (16) by a spring element (44). [10] Steering column assembly according to one of the preceding claims, characterized bythat an electric drive (46) is provided for rotating the gear (16) about its axis of rotation (B).

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