Steer-by-wire steering system

Abstract

The invention relates to a steer-by-wire steering system for a motor vehicle, comprising an axially adjustable steering column, wherein the steering column has a force-feedback assembly with a controller (1), and the force-feedback assembly together with the controller (1) is displaced when the steering column is adjusted. The steering system also comprises a vehicle interface (3) which provides an electric current and control data for the force-feedback assembly. The steering column is equipped with at least two rails (5) which are fixed to the housing and which are electrically connected to the vehicle interface (3), and a contacting module (2) is connected to the controller (1) via a cable (4). The contacting module (2) is moved on the rails (5), and the force-feedback assembly is supplied with a current via the contacting module (2).

Description

[0001]

[0002] Description

[0003] title

[0004] Steer-by-wire steering system

[0005] The present invention relates to a steer-by-wire steering system for a motor vehicle.

[0006] State of the art

[0007] Steer-by-wire steering systems eliminate the mechanical connection between the steering wheel and the steered wheels. The steering angle set on the steering wheel is detected by a sensor and transmitted electronically to the steering actuator, which then adjusts the front wheels accordingly.

[0008] The upper module, also called the steering wheel actuator, includes the steering column adjustment, an end stop to limit the steering wheel rotation, sensors to determine the steering angle and steering torque, and a force feedback unit to simulate steering forces for the driver.

[0009] The steering wheel can be stowed when stationary or for autonomous ferry operation, meaning it retracts very far to give the driver plenty of room. This is achieved by means of large adjustment ranges for the steering column. The steering sensors and the force feedback unit must also be moved across the adjustment ranges.

[0010] The sensors and the force feedback unit must be supplied with power. They also communicate with the vehicle, meaning that the acquired sensor data must be forwarded and the force feedback unit must be controlled.

[0011] The necessary cable connections must be designed in such a way that they can follow thousands of adjustment movements over their lifetime with high adjustment ranges in axial and vertical directions without causing damage.

[0012] Protective devices are used to compensate for, for example, the elongation and compression of the cables during the telescopic movement of the steering column. Furthermore, the telescopic movement must not be obstructed.

[0013] In the prior art, it is also known to route the cables in a cable duct depending on the steering wheel position and to accommodate a cable that is too long in a type of cable drum.

[0014] The routing of the cables is particularly problematic with the new, stowable steering columns with high adjustment ranges.

[0015] The invention is therefore based on the object of providing a device which simplifies the cable routing, in particular in the case of large adjustment ranges of the steering column.

[0016] This problem is solved by the subject matter of claim 1.

[0017] The inventive device comprises a movable contact module that moves along a rail in a sliding or rolling motion. The cables of the force feedback unit are connected to the contact module. This keeps the cables short, and the distance between the contact module and the force feedback unit remains essentially constant, meaning there is no long cable that needs to be routed or accommodated.

[0018] The movable contact module is preferably used for the power supply of the force feedback unit. The power supply cables are thicker and therefore more problematic for large steering column adjustment ranges. In this case, the contact module is moved on at least two rails.

[0019] The cables for data lines are thinner and therefore less problematic. The data lines can also be connected via the contact module. In this case, four or more rails can be used. Alternatively, a rail can be made wide enough to accommodate multiple contact tracks.

[0020] The contact module can have sliding contacts to electrically contact the rails. It then slides over the rails.

[0021] Alternatively, the contact module can have rollers to electrically contact the rails. It then rolls along the rails.

[0022] For example, the steering column can be mechanically connected to the contact module via the axially movable steering column. When the steering column is adjusted axially, the contact module is also moved via the mechanical connection.

[0023] The rails are each firmly fixed at both ends within the vehicle, for example, at one end to the dashboard, where they are also electrically connected to a vehicle interface. The vehicle interface provides the electrical power for the force feedback device and the corresponding data lines.

[0024] For the height adjustment of the steering column, standard cable protection devices can be provided to prevent, for example, excessive bending of the cables.

[0025] Advantageous further training is specified in the dependent claims.

[0026] An embodiment of the invention is explained with reference to the following figures.

[0027] It shows:

[0028] Fig. 1 the steering column according to the invention in the retracted state

[0029] Fig. 2 the steering column according to the invention in the partially extended state

[0030] Figure 1 shows the steering column according to the invention in the retracted state. Steering forces can be simulated on the steering wheel 6 using a force feedback device. The force feedback device has a control unit 1 into which a cable 4 is plugged. Rails 5 are contacted at a vehicle interface 3. The rails 5 are fixed to the body, i.e., the rails 5 can be fixed to the vehicle interface 3 or to the non-movable housing of the steering column (not shown). The housing serves to attach the steering column to the body of the vehicle. A contacting module 2 is moved axially on the rails 5. The contacting module 2 can be moved in a sliding or rolling manner on the rails 5. The cable 4 is electrically connected to the contacting module 2. The rails 5 are made of metal. Electrical current, which is provided at the vehicle interface 3, is conducted to the control unit 1 via the rails 5, the contact module 2 and the cables 4.

[0031] In Figure 2, the steering column according to the invention is partially extended.

[0032] Contacting module 2 is now located in the middle of the rails 5. The length of the cable 4 remains essentially the same.

Claims

Claims 1. Steer-by-wire steering system for a motor vehicle, with an axially adjustable steering column; wherein the steering column has a force feedback unit with a control unit (1), wherein the force feedback unit is moved together with the control unit (1) during the steering column adjustment; with a vehicle interface (3) which provides electrical power and control data for the force feedback unit; characterized in that at least two rails (5) are arranged on the steering column in a housing-fixed manner and are electrically connected to the vehicle interface (3); that a contacting module (2) is connected to the control unit (1) via a cable (4); wherein the contacting module (2) is moved on the rails (5); that the force feedback unit is supplied with power via the contacting module (2).

2. Steer-by-wire steering system according to claim 1, characterized in that the contacting module (2) is moved slidingly over the rails (5).

3. Steer-by-wire steering system according to claim 1, characterized in that the contacting module (2) is moved rolling over the rails (5).

4. Steer-by-wire steering system according to one of claims 1 to 3, characterized in that the contacting module (2) is mechanically connected to the force feedback unit or to a casing tube of the steering column, whereby the contacting module (2) is displaced during the steering column adjustment.

5. Steer-by-wire steering system according to one of claims 1 to 4, characterized in that the rails are made of metal or have a metallic coating.

6. Steer-by-wire steering system according to one of the preceding claims, characterized in that the force feedback unit receives electrical control signals via the contact module (2).

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