Steering device for steer-by-wire system

Abstract

The invention relates to a steering device (10) for a steering-by-wire system of a motor vehicle, comprising a steering handle (16), a force feedback unit (18), a stationary carrier (12) and a bearing unit (14) by means of which the steering handle (16) is rotatably mounted in a circumferential direction (U). The bearing unit (14) in particular has an inner housing (32) and an outer housing (34), which is rotatably mounted on the inner housing (32) and is coupled to the steering handle (16) in a torque-transmitting manner. The force feedback unit (18) has an electric motor (50) and a pinion (56) which is coupled to the electric motor (50) in a torque-transmitting manner and which is in 10-tooth engagement with the toothing (38) of the bearing unit (14) in order to drive the steering handle (16) in the circumferential direction (U) via the bearing unit (14).

Description

Technical Field

[0001] The invention relates to a steering device for a wire-controlled steering system of a motor vehicle. The steering device comprises a steering handle, a force feedback unit and a fixed carrier. Background Art

[0002] Steering devices for steer-by-wire systems are known.

[0003] Unlike typical steering systems, in which the driver's steering movement is mechanically transmitted via the steering column to the steering actuator coupled to the wheels, in steer-by-wire systems the steering movement is transmitted in the form of signals. A force feedback unit, also called a force feedback unit, is provided here to transmit the road feel lost due to the elimination of the steering column to the driver via the steering handle, depending on the driving situation.

[0004] Such steering devices usually include an airbag module which is arranged in the steering handle or the steering wheel to protect the driver. In particular, in the case of asymmetric, large-area steering wheel airbags, efforts are made to keep the airbag module fixed in space, even if the steering wheel is turned. Thus, whether the motor vehicle is turning or driving straight, the asymmetric airbag is always in its ideal, fixed position in space. In order to achieve this rotation compensation, the airbag module has been decoupled from the rotational movement of the steering handle passively by means of a transmission mechanism or actively by means of a servo motor.

[0005] Known steering devices have the disadvantage that they are very heavy and also consist of many parts, in particular if the steering device additionally has an airbag module with rotation compensation. Summary of the invention

[0006] It is therefore an object of the present invention to provide a steering device for a steer-by-wire system which has a particularly compact and simple design.

[0007] The object is achieved by a steering device for a steer-by-wire system of a motor vehicle, the steering device comprising: a steering handle; a force feedback unit; a fixed carrier, the carrier having a receiving pot for an airbag extending in an axial direction; and a bearing unit, by means of which the steering handle is supported on the receiving pot in a circumferential direction so as to be rotatable about the axial direction. The bearing unit has a toothing and is coupled to the steering handle in a torque-transmitting manner. In addition, the force feedback unit has an electric motor and a pinion coupled to the electric motor in a torque-transmitting manner, the pinion being in toothed engagement with the toothing in order to drive the steering handle in a circumferential direction via the bearing unit. In the sense of the present invention, the term "fixed" or "fixed" carrier refers to a carrier that is arranged in a motor vehicle fixedly to the vehicle, in particular during driving. However, the fixed carrier may be adjustable by means of an adjustment mechanism in order to orient the steering handle relative to the driver and thereby improve comfort. In other words, unlike typical steering devices, the fixed carrier is not a steering column that is rotatably supported in the circumferential direction, even if the fixed carrier may be adjustable in height and / or length in a manner similar to a steering column in order to improve driver comfort.

[0008] According to the invention, it has been recognized that the steering device can be designed in this way with a small number of components and in a particularly space-saving and therefore compact manner. This design also has the advantage that the airbag in the receiving container is arranged fixedly in the motor vehicle and thus asymmetrical and even freely configurable airbags can be provided which always provide the same protective effect regardless of the steering position of the steering handle.

[0009] In one embodiment, the toothing is an internal toothing, so that the steering device can be designed even more compactly, in particular in the radial direction, because the electric motor can be arranged at least partially radially within the bearing unit, in particular radially within a housing of the bearing unit.

[0010] Additionally or alternatively, it can be provided that at least the stator and the rotor of the electric motor are arranged outside the bearing unit, preferably outside the housing of the bearing unit, in particular outside the steering handle in the axial direction. In this way, the housing can be designed to be more compact, because no space has to be provided in the housing to accommodate the electric motor. Since a journal is fixed to the rotor, on which the pinion is located or on which the pinion is machined, the journal is not part of the rotor as the name implies. Therefore, the end of the journal on which the pinion is fixed can extend into the space defined by the steering handle, that is, into its hollow interior.

[0011] In another embodiment, the force feedback unit has a secondary motor, which has a second pinion coupled to the secondary motor in a torque-transmitting manner, and the second pinion is in toothed engagement with the toothing so as to drive the steering handle in the circumferential direction via the bearing unit, in particular the housing of the bearing unit. The secondary motor is designed here to be similar to the main motor and in particular can provide the same functions. This has the advantage that, compared with the use of a single motor, the two motors can each be designed to be smaller, so that the steering device can be designed to be more compact. In addition, the steering device can be designed in such a way that when one of the two motors fails, the steering device can continue to operate safely with the help of the other motor. By this redundancy, a particularly high functional safety of the steering device and thus the wire control steering system is ensured.

[0012] Preferably, the supporting unit comprises an inner shell fixed to a carrier in a non-rotatable manner and an outer shell with a toothed portion, the outer shell being supported on the inner shell and rotatably supported on the receiving pot and coupled to the steering handle in a torque-transmitting manner, the pinion being in tooth engagement with the toothed portion so as to drive the steering handle in a circumferential direction via the outer shell of the supporting unit.

[0013] With regard to the secondary motor, similar to the main motor, it is provided that at least the stator and the rotor of the secondary motor are arranged outside the housing in the axial direction, in particular outside the steering handle. Here, it also applies that the end of the journal on which the pinion is fixed can extend into the space defined by the steering handle, i.e., into the hollow interior of the steering handle, because the journal is fixed to the rotor but is not assigned to the rotor.

[0014] Furthermore, the inner shell can be fastened to the receiving cup in order to configure the connection of the support unit to the carrier in a particularly compact manner.

[0015] According to one embodiment, the outer shell is rotatably supported on the inner shell by means of bearings. The bearings are needle bearings, ball bearings and / or plain bearings, which are particularly reliable and cost-effective and can also be designed to be very compact.

[0016] According to another embodiment, the steering device has a gas generator for inflating the airbag. The gas generator is arranged outside the receiving tank, in particular in the carrier. In this way, the receiving tank can be designed to be smaller, because no structural space needs to be reserved for the gas generator.

[0017] In addition, the steering device can have a steering angle sensor unit. In particular, the electric motor and / or the secondary motor here form the sensor of the steering angle sensor unit, so that the electric motor and / or the secondary motor can have multiple functions and the steering device can thus be composed of fewer components.

[0018] Furthermore, it can be provided that the steering handle is fastened to the housing by means of a quick-acting closure which can be operated in particular without tools. This design has the advantage that the steering handle can be replaced with little effort and in a short time. By fastening the steering handle to the housing, the steering device can also be designed to be particularly compact.

[0019] In one embodiment, the steering device has a functional element that matches the steering handle and is connected to the inner housing or the carrier in a rotationally fixed manner. Here, the functional element has a display and / or one or more switches, which are fixedly arranged in the motor vehicle in this way and therefore always have the same orientation regardless of the position of the steering handle. As a result, the display content of the display can always be easily accessed and the switches are always arranged at the same position, so that incorrect operation is avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Further advantages and features emerge from the following description and from the drawings. In these drawings:

[0021] Figure 1 A schematic exploded view showing a steering device for a steer-by-wire system according to the present invention, and

[0022] Figure 2 Show Figure 1 Schematic diagram of the steering device in. DETAILED DESCRIPTION

[0023] Figure 1 A steering device 10 for a steer-by-wire system of a motor vehicle is shown, which has a stationary carrier 12 , a bearing unit 14 , a steering handle 16 and a force feedback unit 18 .

[0024] Furthermore, the steering device 10 has an airbag module 20 with an airbag 22 and a gas generator 24 which is provided for inflating the airbag 22 in the event of a restraint.

[0025] Furthermore, the steering device 10 has a functional element 26 which is associated with the steering handle 16 and is therefore arranged together with the steering handle 16 in the motor vehicle opposite the driver. Figure 2 Not visible or shown.

[0026] The carrier body 12 has a receiving container 28 which extends in the axial direction A and is open at an axial end 30 facing the vehicle interior.

[0027] The airbag 22 is accommodated in the accommodation tank 28, and the gas generator 24 is arranged outside the accommodation tank 28 on the carrier 12 (see Figure 2 ).

[0028] In an alternative embodiment, the gas generator 24 may be accommodated outside of the receiving tank 28 in a recess in the carrier 12 .

[0029] In this regard, the airbag 22 is a driver airbag or a front airbag.

[0030] The bearing unit 14 has a cylindrical inner shell 32 and a cylindrical outer shell 34 as well as a bearing 36 , by means of which the outer shell 34 is supported on the inner shell 32 so as to be rotatable in a circumferential direction U about an axial direction A.

[0031] The bearing 36 here is a needle roller bearing which is particularly compact in the radial direction.

[0032] In an alternative embodiment, the bearing 36 may be any bearing, in particular a ball bearing or a sliding bearing.

[0033] In the present embodiment, the inner shell 32 is mounted on the containing tank 28 .

[0034] Furthermore, the bearing unit 14 has a toothing 38 in the form of an internal toothing which is arranged in the axial direction A opposite the axial end 30 .

[0035] The housing 34 here forms a hub for the steering handle 16 , to which the steering handle 16 is fixed in a rotationally fixed manner by means of a quick-release closure 40 .

[0036] For this purpose, the steering handle 16 has an axial continuation 42 which engages in a complementarily designed recess 44 in the housing 34 and thus couples the steering handle 16 to the housing 34 in a rotationally fixed manner.

[0037] In this case, the receiving cup 28 , the inner shell 32 , the outer shell 34 and the steering handle 16 or the quick-release lock 40 are arranged coaxially and radially adjacent to each other in at least one section.

[0038] The quick-release closure 40 is operable in particular without tools and has, for this purpose, for example, a quick-release tensioning element (not shown).

[0039] In this respect, the functional element 26 is fastened via a correspondingly designed carrier element (not shown) to the carrier 12 , for example to the axial end 30 of the inner shell 32 , and is thus arranged fixedly in the motor vehicle, decoupled from the steering handle 16 .

[0040] In the embodiment shown, the functional element 26 has a display 46 and four buttons or switches 48 .

[0041] In order not to hinder the inflation of the airbag 22 in the case of a restraint, the functional element 26 can be fixed in a known manner so as to be removable from the expansion path of the airbag 22 , for example by means of a flap which can be folded open or ejected.

[0042] The force feedback unit 18 has a primary motor 50 and a secondary motor 52 as well as a control unit 54 which is connected to the motors 50 , 52 in a signal-transmitting manner.

[0043] The primary motor 50 and the secondary motor 52 are designed identically here.

[0044] In order to couple the electric motors 50, 52 to the steering handle 16 in a torque-transmitting manner, the force feedback unit 18 has a first pinion 56 and a second pinion 58, wherein the first pinion meshes with the tooth portion 38 and is connected to the primary electric motor 50 in a torque-transmitting manner, and the second pinion meshes with the tooth portion 38 and is connected to the secondary electric motor 52 in a torque-transmitting manner.

[0045] In this regard, the electric motors 50 , 52 are arranged axially opposite the axial end 30 relative to the receiving pot 28 , and more precisely, such that at least the stator and the rotor (not shown) of each electric motor 50 , 52 are arranged outside the bearing unit 14 and the steering handle 16 in the axial direction A.

[0046] In addition, the steering device 10 is designed so that the electric motors 50, 52 do not extend beyond the housing 34 in the radial direction (see Figure 2 ).

[0047] like Figure 2 As shown, in the present embodiment, the electric motors 50 , 52 are arranged radially within, in particular completely within, the housing 34 .

[0048] The control unit 54 may be part of an onboard computer of the motor vehicle or may be formed by the onboard computer.

[0049] In the present embodiment, the control unit 54 and the electric motors 50 , 52 are further part of a steering angle sensor unit 60 of the steering device 10 , which is provided for detecting a steering movement of the steering handle 16 .

[0050] The steering movement of the steering handle 16 is transmitted to the electric motors 50, 52 by means of the housing 34 via the toothing 38 and detected by means of the control unit 54. Here, the electric motors 50, 52 each form a steering angle sensor of the steering angle sensor unit 60.

[0051] In an alternative specific embodiment, the steering device 10 can have a steering angle sensor unit 60 with a separate control unit and / or at least one separate steering angle sensor which is provided for detecting a steering movement of the steering handle 16 .

[0052] In this way, a steering device 10 for a steer-by-wire system of a motor vehicle is provided which has a particularly compact design.

[0053] Furthermore, the airbag 22 and the functional element 26 are stationary and are therefore arranged independently of a steering movement or an angular position of the steering handle 16 in the circumferential direction U.

[0054] The invention is not limited to the embodiments shown. In particular, individual features of one embodiment can be combined as desired with features of other embodiments, in particular independently of other features of the respective embodiment.

Claims

1. A steering device (10) for a steer-by-wire system of a motor vehicle, comprising: Steering handle (16); Force feedback unit (18); a fixed carrier (12) having a receiving tank (28) for an airbag (22) extending in an axial direction (A); and A support unit (14), by means of which the steering handle (16) is supported on the receiving tank (28) so as to be rotatable in a circumferential direction (U) about an axial direction (A); The bearing unit (14) has a toothing (38) and is coupled to the steering handle (16) in a torque-transmitting manner. The force feedback unit (18) has an electric motor (50) and a pinion (56) coupled to the electric motor (50) in a torque-transmitting manner and in toothed engagement with a toothed arrangement (38) in order to drive a steering handle (16) via a bearing unit (14) in a circumferential direction (U).

2. The steering device (10) according to claim 1, characterized in that: The toothing (38) is an internal toothing.

3. The steering device (10) according to claim 1 or 2, characterized in that At least a stator and a rotor of the electric motor (50) are arranged outside the bearing unit (14) in an axial direction (A), in particular outside the steering handle (16).

4. Steering device (10) according to one of the preceding claims, characterized in that The force feedback unit (18) has a secondary motor (52) having a second pinion (58) coupled to the secondary motor (52) in a torque-transmitting manner and in toothed engagement with the toothing (38) in order to drive a steering handle (16) via a bearing unit (14) in a circumferential direction (U).

5. Steering device (10) according to one of the preceding claims, characterized in that The bearing unit (14) comprises an inner shell (32) fixed to a carrier (12) in a rotationally fixed manner and an outer shell (34) with a toothing (38); the outer shell (34) is supported on the inner shell (32) and rotatably supported on a receiving pot (28) and is coupled to a steering handle (16) in a torque-transmitting manner; a pinion (56, 58) is in toothed engagement with the toothing (38) so as to drive the steering handle (16) in a circumferential direction (U) via the outer shell (34) of the bearing unit (14).

6. The steering device (10) according to claim 5, characterized in that The inner shell (32) is fixed on the containing tank (28).

7. The steering device (10) according to claim 5 or 6, characterized in that: The outer housing (34) is rotatably supported on the inner housing (32) by means of a bearing (36), which is a needle bearing, a ball bearing and / or a plain bearing.

8. Steering device (10) according to one of the preceding claims, characterized in that The steering device (10) has a gas generator (24) for inflating an airbag (22), the gas generator (24) being arranged outside a receiving tank (28), in particular in a carrier (12).

9. Steering device (10) according to one of the preceding claims, characterized in that The steering device (10) has a steering angle sensor unit (60), in particular the electric motor (50) and / or the secondary electric motor (52) form a sensor of the steering angle sensor unit (60).

10. Steering device (10) according to one of the preceding claims, characterized in that The steering handle (16) is fastened to the housing (34) by means of a quick-acting closure (40) which can be operated, in particular without tools.

11. Steering device (10) according to one of the preceding claims, characterized in that The steering device (10) has a functional element (26) matched to the steering handle (16), which is connected to the inner housing (32) in a rotationally fixed manner, and has a display (46) and / or one or more switches (48).

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