Operating arrangement for a steer-by-wire steering system of a motor vehicle

Abstract

Operating arrangement for a steer-by-wire steering system of a motor vehicle, comprising a mechanical control element (1) arranged in a passenger compartment of the motor vehicle for inputting a steering request by the hand of a driver of the motor vehicle, wherein the control element (1) is rotatably mounted about a predetermined axis of rotation, comprising a feedback device for generating haptic feedback to the driver of the motor vehicle, wherein the feedback device comprises an electric motor (3) which transmits the rotary motion to the control element via a traction gear (2), wherein the traction gear (2) comprises two discs (8, 9) which are arranged on the shaft (10) of the electric motor (3), wherein the traction gear (2) comprises two discs (4, 5) which are arranged on the control element (1), wherein the traction gear (2) comprises a first traction element (6) which is rigidly connected at its ends to the disc (4) and to the disc (8),wherein the traction element drive (2) comprises a second traction element (7) which is rigidly connected at its ends to the disk (5) and to the disk (9), wherein the traction elements (6, 7) are arranged in opposite directions, so that when the electric motor (3) rotates, one traction element (6, 7) is wound onto the disk (8, 9) and one traction element (6, 7) is unwound onto the disk.

Description

[0001] The present invention relates to an operating arrangement for a steer-by-wire steering system of a motor vehicle. State of the art

[0002] To implement the driver's steering input, steering wheels are currently used in passenger cars. By specifying an angle on the steering wheel, the driver can determine the rack position and thus the direction in which the vehicle steers. In conventional vehicles, the steering wheel and wheels are mechanically connected. The rotational movement is transmitted from the steering wheel via the steering column and intermediate steering shaft to a gear, which converts the rotational movement into a translational movement of the rack. This, in turn, rotates the wheels to the desired position.

[0003] An example of an alternative control element is a joystick, which originates from the gaming industry. Areas where steering vehicles with a joystick is used include aviation and commercial vehicles.

[0004] The automotive industry's move toward highly automated driving is leading to new demands regarding the steering system. For example, many automakers desire that the steering wheel not turn when the autopilot takes over control of the vehicle. This desire can be realized by eliminating the mechanical connection between the steering wheel and the wheels and instead communicating steering inputs via cable (steer-by-wire). Another assumption is that the steering wheel, in its current position, is in the driver's way when driving with autopilot.

[0005] If the driver no longer has to drive, they could, for example, work on a laptop or read a newspaper while driving. For this purpose, the steering wheel is more likely to be in the driver's way; a storage compartment, for example, would be more useful.

[0006] To meet these requirements for future vehicles, a new vehicle interior concept is required, including an alternative operating concept. Furthermore, it is desirable to provide the driver with feedback related to the current driving situation, similar to a conventional steering system with a mechanical through-drive.

[0007] DE 10 2017 211 253 A1 discloses an operating arrangement for a steer-by-wire steering system, wherein the operating element is rotated by rotating the driver's forearm when the driver's hand is placed on the steering wheel. A feedback device is also provided, which can generate haptic feedback from the operating element to the driver depending on the driving situation.

[0008] In such feedback devices, an electric motor is mounted on the control panel, which transmits torque to the control panel via a gear. Belt drives are suitable for transmitting the motor's rotary motion.

[0009] However, belt drives can be disadvantageous due to torque ripple and backlash. Furthermore, slippage can occur, especially under high forces.

[0010] It is therefore an object of the invention to provide a gear for the feedback device of an operating arrangement which is smooth-running, has a high degree of reaction, almost no torque ripple and almost no backlash.

[0011] The invention is achieved with an operating arrangement for a steer-by-wire steering system of a motor vehicle having the features of patent claim 1. Disclosure of the invention

[0012] The present invention provides an operating arrangement for a steer-by-wire steering system of a motor vehicle, comprising a mechanical operating element arranged in a passenger compartment of the motor vehicle for inputting a steering request from a driver of the motor vehicle, wherein the operating element is mounted rotatably about a predetermined axis of rotation and comprising a feedback device for generating haptic feedback to the driver of the motor vehicle, wherein the feedback device has an electric motor which transmits the rotary movement to the operating element via a traction mechanism transmission.The traction mechanism comprises two pulleys arranged on the shaft of the electric motor, two pulleys arranged on an axis on the control element, a first traction mechanism whose ends are connected to the pulley on the motor and to the pulley on the control element, and a second traction mechanism whose ends are connected to the pulley on the motor and to the pulley on the control element. The traction mechanisms are arranged in opposite directions, so that when the electric motor rotates, one traction mechanism is wound onto the pulley and the other is unwound from the pulley. This advantageously ensures that both belts are always under tension, resulting in a backlash-free transmission.

[0013] Another idea of ​​the present invention is that the diameter of the pulleys on the control element changes continuously, so that the same gear ratio between the transmission input and output is achieved at every angular position. The effective diameter of the pulleys on the control element changes as the traction mechanism is wound and unwound. The variable diameter of the pulleys compensates for the change in the effective diameter.

[0014] Advantageous embodiments and further developments emerge from the subclaims and from the description with reference to the figures.

[0015] According to a preferred embodiment, the traction mechanism is a flat belt. The use of a flat belt results in a transmission without torque ripple. In contrast to toothed belt drives, very small diameters can be used at the transmission input to achieve higher gear ratios without risking slippage. Alternatively, the traction mechanism can also be a cable.

[0016] According to a further development, the traction mechanism has at least one tensioning pulley for tensioning the traction mechanism. Such tensioning pulleys are typically pre-tensioned against the traction mechanism by a spring.

[0017] The control arrangement is preferably located on the vehicle's center console. The control arrangement can be aligned horizontally along the vehicle's length. The driver grasps the control element and can steer the vehicle, for example, by twisting their forearm. However, the control arrangement can also be aligned vertically. This means that the control element protrudes upwards, allowing the driver to steer the vehicle by swiveling their wrist.

[0018] An embodiment is described using the figures. They show: Fig. 1 the operating arrangement according to the invention Fig. 2 the traction mechanism in a view from the front Fig. 3 the traction mechanism in a side view

[0019] In the Fig. Figure 1 shows the operating arrangement according to the invention with the feedback device. Two pulleys 8, 9 are arranged on the shaft 10 of an electric motor 3. The pulleys 8, 9 have a drum-like shape so that they can guide a belt.

[0020] The operating arrangement also includes the operating element 1, which is shaped so that it can be grasped by the driver's hand. The discs 4, 5 are arranged on the operating element 1. The discs 4, 5 are significantly larger than the discs 8, 9. The tensioning devices 6, 7 are tensioned between the discs 4, 5, 8, and 9. The operation is illustrated in the following figures.

[0021] In the Fig. 2 and Fig. Figure 3 shows the traction drive in detail. The smaller pulleys 8, 9 are connected to the motor shaft 10. The larger pulleys 4, 5 are connected to an axle of the control element 1.

[0022] A first traction element 6 is firmly connected to pulley 4 and pulley 8. A second traction element 7 is firmly connected to pulley 5 and pulley 9. The second traction element 7 is arranged in the opposite direction. When the electric motor 3 rotates counterclockwise, the traction element 6 is wound onto pulley 8 and unwound from pulley 4. At the same time, the traction element 7 is unwound from pulley 9 and wound onto pulley 5.

[0023] When the electric motor 3 rotates clockwise, the traction element 7 is wound onto the pulley 9 and unwound from the pulley 5. At the same time, the traction element 6 is unwound from the pulley 8 and wound onto the pulley 4.

[0024] In the embodiment, the two traction means 6, 7 are designed as flat belts.

[0025] The two pulleys 4 and 5 have a continuously changing diameter. The effective diameter of the pulleys 4 and 5 changes as the belt is wound and unwound. The variable diameter of the pulleys 4 and 5 compensates for the change in the effective diameter. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2017 211 253 A1

[0007]

Claims

[1] Operating arrangement for a steer-by-wire steering system of a motor vehicle, with a mechanical operating element (1) arranged in a passenger compartment of the motor vehicle for inputting a steering command by the hand of a driver of the motor vehicle, wherein the operating element (1) is mounted rotatably about a predetermined axis of rotation; and with a feedback device for generating haptic feedback to the driver of the motor vehicle, wherein the feedback device has an electric motor (3) which transmits the rotary movement to the operating element via a traction mechanism (2), characterized by , that the traction mechanism (2) comprises two discs (8, 9) which are arranged on the shaft (10) of the electric motor (3), that the traction mechanism (2) comprises two discs (4, 5) which are arranged on the operating element (1), wherein the traction mechanism (2) comprises a first traction means (6) which is firmly connected by its ends to the disc (4) and to the disc (8), wherein the traction mechanism (2) comprises a second traction means (7) which is firmly connected by its ends to the disc (5) and to the disc (9), wherein the traction means (6, 7) are arranged in opposite directions, so that during rotation of the electric motor (3) a traction means (6, 7) is wound up on the disc (8, 9) and a traction means (6, 7) is unwound on the disc. [2] Operating arrangement according to claim 1, characterized by that the diameter of the discs (4, 5) changes continuously, so that the same gear ratio between the gearbox input and the gearbox output results at every angular position. [3] Operating arrangement according to claim 1 or 2, characterized by that the traction means (6, 7) is a flat belt. [4] Operating arrangement according to claim 1 or 2, characterized bythat the traction means (6, 7) is a rope. [5] Operating arrangement according to one of the preceding claims, characterized by that the traction mechanism (2) has at least one tensioning roller for tensioning the traction means (6, 7). [6] Operating arrangement according to one of the preceding claims, characterized by that the operating arrangement is arranged horizontally or vertically on a center console of the motor vehicle.

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