Steering column adjustment unit

Abstract

Adjustment unit of a steering column of a vehicle in which a steering spindle is rotatably mounted about a longitudinal axis and has a shell unit which has shell tubes (5) arranged axially relative to each other in a telescopic manner, comprising at least a first shell tube in which at least a second shell tube is received, wherein at least one bearing element (1) is arranged between the shell tubes, characterized in that the bearing element (1) is formed by means of two ramp-shaped elements (2, 4) pre-tensioned to each other, which are axially adjustable in height.

Description

Field of the invention

[0001] The present invention relates to an adjustment unit of a steering column of a vehicle according to the preamble of patent claim 1 and a steer-by-wire steering system with such an adjustment unit. Background of the invention

[0002] In today's steering systems and steering devices, the steering wheel can be adjusted in height and length, i.e., in an axial position. In such adjustment systems, the steering column elements or steering shaft elements are movable relative to each other, for example, designed as a telescopic arrangement. This allows the steering wheel to be adjusted to a position that suits the driver.

[0003] Steer-by-wire steering systems are also known, which dispense with the mechanical connection between the steering wheel and the axle to be steered via the steering column, and the steering of the wheels is controlled via corresponding signals. Two types of steer-by-wire steering systems can be distinguished: steer-by-wire steering systems with a force feedback actuator remote from the steering wheel and steer-by-wire steering systems with a force feedback actuator close to the steering wheel.

[0004] Steer-by-wire steering systems with a force-feedback actuator located away from the steering wheel utilize common crash elements, such as metal strips that plastically deform when a defined force is exceeded. Plastic sleeves on the telescopic steering shaft are also known, which are destroyed by a predetermined force. Steer-by-wire steering systems with a force-feedback actuator located close to the steering wheel can eliminate the need for a telescopic steering shaft.

[0005] Furthermore, in such steering column adjustment systems, the steering column housing parts must be able to move relative to each other. This is achieved by a telescopic arrangement of the housing parts. This allows the steering wheel to be adjusted to a position that is convenient for the driver. A recent requirement has been to retract the steering wheel into a stowed position within the dashboard.

[0006] WO 2022 / 043 533 A1 describes a one-piece extension with a continuous transition and screw connection of the steering wheel connection.

[0007] From EP 3 476 692 A1 a steering column with a one-piece steering column adjustment is known.

[0008] From the generic US 2021 / 0 213 998 A1 an adjusting unit of a steering column of a vehicle is known, in which a steering spindle is mounted rotatably about a longitudinal axis and has a casing unit which has casing tubes arranged axially telescopically relative to one another, comprising at least a first casing tube in which at least a second casing tube is received, wherein at least one bearing element is arranged between the casing tubes. Summary of the invention

[0009] It is therefore an object of the present invention to provide an improved adjustment unit.

[0010] This object is achieved by an adjustment unit having the features of claim 1 and by a steer-by-wire steering system having the features of claim 5.

[0011] According to the invention, the object is achieved by an adjustment unit of a steering column of a vehicle, in which a steering spindle is mounted so as to be rotatable about a longitudinal axis and has a casing unit which has casing tubes arranged so as to be telescopic relative to one another, comprising at least one first casing tube, which is received in at least one second casing tube, wherein at least one bearing element is arranged between the casing tubes, wherein the bearing element is formed by means of two ramp-shaped elements which are prestressed relative to one another and which are axially adjustable in height.

[0012] Preferably, the ramp-shaped elements are rotationally symmetrical. This is necessary so that the two ramp-shaped elements can be adjusted in height axially relative to the rotation by rotating one of them over the other. This creates an axial movement.

[0013] According to one embodiment of the invention, a spring element is arranged between the ramp-shaped elements. The spring element generates the required preload between the two ramp-shaped elements. All types of springs are possible, e.g., torsion springs, compression springs, or elastomers.

[0014] Preferably, the two elements are preloaded against each other in the direction of rotation, so that the rotation is automatically triggered by the preload when the friction is overcome and stops when the axial height adjustment has closed the gap between the casing tubes specified by the installation space.

[0015] According to the invention, the ramp-shaped elements have a ramp angle that is designed to be self-locking. This prevents reverse rotation due to axial pressure. This mechanism adjusts the height of the sliding shoe system to the gap size, but cannot be reduced again. The maximum possible angle for self-locking is defined by the coefficient of friction. The following condition applies: tan (Alpha)<=mue, where mue defines the coefficient of friction. The following can be considered an example: For example, the maximum angle can be assumed to be: arctan (0.2) = 0.2 rad.

[0016] The angle can be used to calculate the maximum gradient of the ramp.

[0017] Preferably, the ramp-shaped elements have multiple ramps. This allows for a larger working area in an axial direction.

[0018] Preferably, a steer-by-wire steering system of a vehicle is provided, comprising a spindle, a steering element which is coupled to the spindle in an axially fixed and torque-transmitting manner, and an adjustment unit, wherein the spindle is arranged within the extension support and is coupled to the inner extension element in an axially fixed manner. Short description of the drawing

[0019] An exemplary embodiment of the invention is illustrated below with reference to five figures. They show: Fig. 1 an exploded view of a bearing element of an adjustment unit according to the invention, Fig. 2 a longitudinal section through the wedge element, and Fig. 3 to 5 an exploded view of a bearing element of an adjustment unit according to the invention Detailed description of the drawings

[0020] For the explanations of the figures, reference is made to the Fig. 1 to 5, each of which shows a bearing element 1 of an adjustment unit (not shown in detail) of a steering column of a vehicle.

[0021] The bearing element 1 consists of three main parts: a first ramp-shaped element 2, a spring element 3, and a second ramp-shaped element 4, which serves as a friction element. By means of this bearing element 1, a gap S between a casing tube 5 and the second ramp-shaped element 4 is to be adjusted by rotating the first ramp-shaped element 4 against the second ramp-shaped element 4 via ramps. The rotational movement is caused by the spring element 3. All types of spring elements are possible, e.g., torsion springs, compression springs, or elastomers. One of the ramp-shaped elements 2, 4 must be pre-rotated to a maximum spring force in order to obtain the minimum center distance of the bearing element 1.

[0022] This can be done externally by rotating the first ramp-shaped element 2. The two ramp-shaped elements 2, 4 rotate until their axial distance reaches the desired distance or the possible spring travel is at its limit. Since the two ramp-shaped elements 2, 4 are self-locking, they do not return to their original position.

[0023] Furthermore, Fig. 4 that a rotation stop 6 is provided, which prevents rotation by moving ramp-shaped elements 2, 4. This rotation stop 6 is designed such that it allows axial movement between the ramp-shaped elements 2, 4 and the casing tube 5. List of reference symbols 1 bearing element 2 first ramp-shaped element 3 spring element 4 second ramp-shaped element 5 jacket pipe 6 Rotation stop S gap

Claims

[1] Adjustment unit of a steering column of a vehicle, in which a steering spindle is mounted so as to be rotatable about a longitudinal axis and has a casing unit which has casing tubes (5) arranged so as to be telescopic relative to one another, comprising at least one first casing tube in which at least a second casing tube is accommodated, wherein at least one bearing element (1) is arranged between the casing tubes, the bearing element (1) being formed by means of two ramp-shaped elements (2, 4) which are prestressed relative to one another and are axially adjustable in height, characterized by that the ramp-shaped elements (2,4) have a ramp angle which is self-locking. [2] Adjustment unit according to claim 1, wherein the ramp-shaped elements (2, 4) are rotationally symmetrical. [3] Adjustment unit according to one of the preceding claims, wherein a spring element (3) is arranged between the ramp-shaped elements (2, 4). [4] Adjustment unit according to one of the preceding claims, wherein the two ramp-shaped elements (2, 4) are prestressed against each other in a direction of rotation. [5] Steer-by-wire steering system comprising an adjusting unit according to one of the preceding claims.

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