ACTUATOR OF A STEERING SYSTEM OF A MOTOR VEHICLE

Abstract

An actuator of a steering system of a motor vehicle, having a connecting rod which is longitudinally movable in a housing along an actuating path between axial stops and which penetrates the housing and is connectable at one end to a toe link for the articulation of wheels, the stops of which are arranged axially one behind the other and face each other axially. The stops and a stopper interacting with the two stops are located inside the housing.

Claims

1. An actuator of a steering system of a motor vehicle, the actuator comprising a connecting rod longitudinally movable in a housing along an actuating path between two axial stops, the connecting rod penetrating the housing and configured for articulation of wheels, and the two axial stops are arranged axially behind one another and facing each other axially, and a stopper interacting with the two axial stops is located inside the housing.

2. The actuator according to claim 1, wherein the connecting rod includes: a threaded spindle of a screw drive, and a first connecting rod part non-rotatably connected to the threaded spindle, the first connecting rod part having the stopper engaging between the two axial stops arranged on the housing.

3. The actuator according to claim 1, wherein the connecting rod includes: a threaded spindle of a screw drive, and a first connecting rod part non-rotatably connected to the threaded spindle, and the first connecting rod part provided with the stopper.

4. The actuator according to claim 2, wherein the first connecting rod part is configured as an anti-rotation device for the connecting rod.

5. The actuator according to claim 2, wherein the housing further comprises a housing opening covered by a cover, the housing opening provided on its axially opposite sides with the two axial stops.

6. The actuator according to claim 5, wherein the two axial stops are formed on at least one insert inserted in the housing opening.

7. The actuator according to claim 5, wherein the cover is provided with the two axial stops.

8. The actuator according to claim 2, further comprising a linear displacement sensor configured for detecting an axial position of the connecting rod, and a signal transmitter of the linear displacement sensor is arranged on the connecting rod and a signal receiver of the linear displacement sensor, covering the actuating path, is associated with the housing.

9. The actuator according to claim 8, wherein the linear displacement sensor is a non-contact linear displacement sensor, and includes an electrically conductive signal transmitter configured to form the stopper.

10. The actuator according to claim 1, further comprising: a screw drive, a motor configured to drive the screw drive, and a threaded spindle non-rotatably arranged within the housing, the threaded spindle to move axially within the housing.

11. The actuator according to claim 1, wherein the stopper is configured as a signal transmitter for a linear displacement sensor.

12. An actuator for a steering system of a motor vehicle, the actuator comprising: a housing having two axial stops, the two axial stops facing each other, a connecting rod longitudinally movable within the housing along an actuating path defined by the two axial stops, and longitudinal movement of the connecting rod is configured to move at least one wheel of the motor vehicle, a stopper mounted on the connecting rod, the stopper configured to abut with each of the two axial stops.

13. The actuator according to claim 12, wherein the connecting rod is configured as part of a screw drive.

14. The actuator according to claim 12, wherein the connecting rod is configured as part of a planetary roller screw drive.

15. The actuator according to claim 12, wherein the connecting rod is configured to non-rotatably engage the housing such that rotation of the connecting rod relative to the housing is prevented.

16. The actuator according to claim 12, wherein the stopper is configured to be axially adjustably mounted to the connecting rod.

17. The actuator according to claim 12, wherein the stopper is configured as a signal transmitter for a linear displacement sensor.

18. The actuator according to claim 17, wherein the stopper moves axially within an opening of the housing, and a cover for the opening is configured as a signal receiver for the linear displacement sensor.

19. An actuator for a steering system of a motor vehicle, the actuator comprising: a housing, a connecting rod longitudinally movable within the housing along an actuating path defined by two axial stops arranged axially behind one another and facing each other axially, and longitudinal movement of the connecting rod is configured to move at least one wheel of the motor vehicle, a linear displacement sensor arranged within the housing, the linear displacement sensor configured for detecting an axial position of the connecting rod, the linear displacement sensor having: a signal transmitter arranged within the housing, the signal transmitter configured to abut with each of the two axial stops such that the signal transmitter and a first of the two axial stops define a first end of the actuating path and the signal transmitter and a second of the two axial stops define a second end of the actuating path, and a signal receiver arranged within the housing, the signal receiver configured to cooperate with the signal transmitter to detect the axial position of the connecting rod within the actuating path, the signal receiver arranged within the housing.

20. The actuator according to claim 19, further comprising a planetary roller screw drive configured to cooperate with threads of the connecting rod to move the connecting rod along the actuating path.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The disclosure is explained in more detail below with reference to two exemplary embodiments shown in five figures altogether. In the drawings:

[0019] FIG. 1 shows an actuator in one view;

[0020] FIG. 2 shows a detail of the actuator from FIG. 1 in a longitudinal sectional view;

[0021] FIG. 3 shows an enlargement of the detail from FIG. 2;

[0022] FIG. 4 shows a variant of the actuator in an enlarged detail view as in FIG. 3;

[0023] FIG. 5 shows a cross-sectional view of the detail of the actuator from FIG. 2.

DETAILED DESCRIPTION

[0024] FIGS. 1 and 2 show an actuator of a rear-axle steering system of a motor vehicle, comprising a multi-part connecting rod 3 which is arranged in a housing 1 in a manner longitudinally displaceable along an actuating path and which penetrates the housing 1 and is provided at the end with fork heads 4 which are screwed to the ends of the connecting rod 3. The fork heads 4 are connected to toe links, not shown, which in turn articulate wheels, not shown, of the rear axle. Such actuators can also be referred to as central actuators.

[0025] The housing 1 is divided into two housing parts 5, 6 transversely with respect to the connecting rod axis. An electric motor 7 is screwed to the housing 1 and drives a planetary roller screw drive 8 (rotation-translation gear) via a toothed belt drive (rotation-rotation gear), not shown, the planetary rollers 9 of said planetary roller screw drive meshing with a thread 10 of a threaded spindle 11, which is part of the connecting rod 3. Under the rotary drive of a planetary roller carrier 12, the planetary rollers 9 rotate about their axes and around the non-rotatable threaded spindle 11. A full revolution of the planetary roller carrier 12 forces an axial advancement of the connecting rod 3 by the amount of the pitch of the thread 10 of the threaded spindle 11.

[0026] The connecting rod 3 is composed of a plurality of components that are rigidly connected to one another. It comprises the threaded spindle 11 and further connecting rod parts, of which the first connecting rod part 13 screwed together with the threaded spindle 11 is designed as an anti-rotation device 14 of the connecting rod 3. This anti-rotation device 14 has a dihedron 15 which is mounted on counter surfaces 16 on the housing (FIG. 5).

[0027] Starting from the neutral position shown in FIG. 1—where both wheels are set for straight-ahead travel—the axial actuating path of the connecting rod 3 is interlockingly delimited in both axial directions by an actuating path delimiter 17.

[0028] FIG. 3 shows a detail of the actuating path delimiter 17, which has a pin-like stopper 18 which is screwed to the anti-rotation device 14. The stopper 18 engages between two stops 19 on the housing which are arranged axially one behind the other and face each other. When the connecting rod 3 is moved axially in one direction, the stopper 18 strikes against one of the stops 19 at the end of the actuating path. When the connecting rod is moved axially in the other direction, the stopper 18 strikes against the other stop 19 at the end of the actuating path.

[0029] The housing 1 has a housing opening 20 which is covered by a cover 21. Housing walls 22 of the housing opening 20 lying axially opposite one another form the stops 19 in this exemplary embodiment.

[0030] FIG. 4 shows a variant with inserts 23, which are inserted in the housing opening 20 and form stops 24 between which the stopper 18 can move. The axial extension of the inserts 23 is matched to the desired actuating path.

[0031] The actuator is provided with a non-contact linear displacement sensor 25, specifically with a capacitive linear displacement sensor 25 for detecting an axial position of the connecting rod 3. An electrically conductive signal transmitter 26—also referred to as a target—is screwed onto the anti-rotation device 14 of the connecting rod 3. The cover 21 includes a signal receiver 27, which is provided with a large number of coils, not shown in any further detail, and which extends over the length of the actuating path of the connecting rod 3.

[0032] In the exemplary embodiment, the stopper 18 is formed by the pin-like signal transmitter 26. This component therefore has a dual function, on the one hand functioning as a signal transmitter for the linear displacement sensor and on the other hand functioning as a stopper for the actuating path delimiter. For calibration purposes, the signal receiver 27, which is screwed tight with a screw 28, is provided with an elongated hole 29, such that when the screw 28 is loosened, the signal receiver 27 can be displaced axially on the anti-rotation device 14 for calibration.

LIST OF REFERENCE SYMBOLS

[0033] 1 Housing [0034] 3 Connecting rod [0035] 4 Fork head [0036] 5 Housing part [0037] 6 Housing part [0038] 7 Electric motor [0039] 8 Planetary roller screw drive [0040] 9 Planetary roller [0041] 10 Thread [0042] 11 Threaded spindle [0043] 12 Planetary roller carrier [0044] 13 First connecting rod part [0045] 14 Anti-rotation device [0046] 15 Dihedron [0047] 16 Counter surfaces [0048] 17 Actuating path delimiter [0049] 18 Stopper [0050] 19 Stop [0051] 20 Housing opening [0052] 21 Cover [0053] 22 Housing wall [0054] 23 Insert [0055] 24 Stop [0056] 25 Linear displacement sensor [0057] 26 Signal transmitter [0058] 27 Signal receiver [0059] 28 Screw [0060] 29 Elongated hole