Steering System Having an Electromechanical Steering Actuator and Method for Equipping a Vehicle and Vehicle Therewith

Abstract

A steering system (11) for a vehicle (10) includes an electromechanical steering actuator (46) and a steering linkage (37) movable depending on the steering actuator (46). The linkage (37) includes a steering rod (30) adapted to be connected in an articulated manner to the steering knuckle (22) or an articulated lever (24) of the steering knuckle (22) for moving the steering knuckle (22). The linkage (37) further comprises a bell crank (35) having a first end area (39) connected in an articulated manner to the steering rod (30) and a second end area (40) connected in an articulated manner to a vehicle frame (12) of the vehicle (10) or to the steering actuator (46). A point of application (63) of the steering actuator (46) on the steering linkage (37) is spaced apart from the second end area (40) of the bell crank (38).

Claims

1. A steering system (11) for a vehicle (10), comprising: an electromechanical steering actuator (46); and a steering linkage (37) which can be moved as a function of the steering actuator (46) and comprises a steering rod (30), wherein the steering rod (30) is adapted to be connected in an articulated manner to a steering knuckle (22) or to an articulated lever (24) of the steering knuckle (22) in order to move the steering knuckle (22) of the vehicle (10); a first bell crank (38) which is connected in an articulated manner to the steering rod (30) in a first end area (39) of the first bell crank (38) and is adapted in a second end area (40) of the first bell crank (38) to be connected in an articulated manner to a vehicle frame (12) of the vehicle (10) or to the steering actuator (46), wherein a point of application (63) of the steering actuator (46) on the steering linkage (37) lies spaced apart from the second end area (40) of the first bell crank (38).

2. The steering system (11) according to claim 1, wherein the steering actuator (46) is connected in an articulated manner to the steering rod (30) in a central area (60) of the steering rod (30).

3. The sleeting system (11) according to claim 1, wherein the steering linkage (37) further comprises a coupling rod (74) and a second bell crank (76), wherein the second bell crank (76) is adapted in a first end area (77) of the second bell crank (76) or a central region (79) of the second bell crank (76) to be connected in an articulated manner to the vehicle frame (12) of the vehicle (10) or to the steering actuator (46), the second bell crank (76) is connected in an articulated manner to a first end area (82) of the coupling rod (74) and the coupling rod (74) is connected in an articulated manner in its second end area (88) to the first bell crank (38), wherein the steering actuator (46) is connected in an articulated manner to the coupling rod (74) or to the second bell crank (76).

4. The steering system (11) according to claim 3, wherein the steering actuator (46) is adapted to be connected in an articulated manner to the vehicle frame (12) of the vehicle (10) by means of a first pivot joint (98).

5. The steering system (11) according to claim 3, wherein the first bell crank (38) is adapted to be connected to the vehicle frame (12) of the vehicle (10) or the steering actuator (46) by means of a second pivot joint (44), and the second bell crank (76) is adapted to be connected to the vehicle frame (12) of the vehicle (10) or the steering actuator (46) by means of a third pivot joint (80), and wherein the coupling rod (74) is connected in the first end area (82) of the coupling rod (74) via a fourth pivot joint (86) to the second bell crank (76) and in the second end area (88) of the coupling rod (74) via a fifth pivot joint (92) to the first bell crank (38).

6. The steering system (11) according to claim 1, wherein the steering rod (30) is connected in an articulated manner to the first bell crank (38) via a first ball joint (36) and is adapted to be connected in an articulated manner to the steering knuckle (22) or an articulated lever (24) of the steering knuckle (22) via a second ball joint (28).

7. The steering system (11) according to claim 1, wherein the steering rod (30) has a length (L) which is at least twice as long as a bell crank length (l) of the first bell crank (38).

8. The steering system (11) according to claim 1, wherein the first bell crank (38) is adapted to be connected in an articulated manner to the vehicle frame (12) via a second pivot joint (44).

9. The steering system (11) according to claim 1, wherein the electromechanical steering actuator (46) is an electrical linear actuator (48) with a spindle drive (50).

10. A vehicle (10), comprising: a steering knuckle (22); and, a steeling system (11) including an electromechanical steering actuator (46); and a steering linkage (37) which can be moved as a function of the steering actuator (46) and comprises a steering rod (30), wherein the steering rod (30) is adapted to be connected in an articulated manner to a steering knuckle (22) or to an articulated lever (24) of the steering knuckle (22) in order to move the steering knuckle (22) of the vehicle (10), a first bell crank (38) which is connected in an articulated manner to the steering rod (30) in a first end area (39) of the first bell crank (38) and is adapted in a second end area (40) of the first bell crank (38) to be connected in an articulated manner to a vehicle frame (12) of the vehicle (10) or to the steering actuator (46), wherein a point of application (63) of the steering actuator (46) on the steering linkage (37) lies spaced apart from the second end area (40) of the first bell crank (38).

11. The vehicle according to claim 10, wherein the vehicle frame (12) of the vehicle (10) has a mounting position (45) for a steering gear (160) or a steering column lever (156) of a hydraulic steering system (152) and the first bell crank (38) on the vehicle (10) is connected in an articulated manner to the vehicle frame (12) of the vehicle (10) or the steering actuator (46) at or in the region of the mounting position (45) of the vehicle frame (12).

12. The vehicle according to claim 10 wherein the steering actuator (46) is connected to the vehicle frame (10) of the vehicle by means of the first pivot joint (98).

13. The vehicle (10) according to claim 10 wherein the vehicle frame (12) of the vehicle (10) has a mounting position (45) for a steering gear (160) or a steering column lever (156) of a hydraulic steering system (152) and the steering actuator (46) is arranged in the longitudinal direction (13) of a vehicle frame (12) pf the vehicle (10) in the direction of a vehicle front side (67) in front of the mounting position (45) for a steering gear (160) or a steering column lever (156) of a hydraulic steering system (152).

14. A method for equipping a vehicle (10) with a steering system (11) including an electromechanical steering actuator (46) and a steering linkage (37) which can be moved as a function of the steering actuator (46), the steering linkage (37) comprising a steering rod (30), wherein the steering rod (30) is adapted to be connected in an articulated manner to a steering knuckle (22) or to an articulated lever (24) of the steering knuckle (22) in order to move the steering knuckle (22) of the vehicle (10), and a first bell crank (38) which is connected in an articulated manner to the steering rod (30) in a first end area (39) of the first bell crank (38), the method comprising the steps of: identifying (20) a mounting position (45) on the vehicle frame (12) of the vehicle (10) for a steering gear (160) or a steering column lever (156) of a hydraulic steering system (152); and connecting (202), at the mounting position (45) or in the area of the mounting position (45), a second end area (40) of the first bell crank (38) in an articulated manner to the vehicle frame (12) of the vehicle (10) or to the steering actuator (46) wherein a point of application (63) of the steering actuator (46) on the steering linkage (37) lies spaced apart from the second end area (40) of the first bell crank (38).

15. The method according to claim 14 wherein the steering actuator (46) is connected (204) in an articulated manner in the longitudinal direction (13) of the vehicle frame (12) in the direction of a vehicle front side (67) in front of the mounting position (45).

16. The method according to claim 14 wherein the steering linkage (37) further comprises a coupling rod (74) and a second bell crank (76), the second bell crank (76) adapted in a first end area (77) of the second bell crank (76) or a central region (79) of the second bell crank (76) to be connected in an articulated manner to the vehicle frame (12) of the vehicle (10) or to the steering actuator (46), the second bell crank (76) connected in an articulated manner to a first end area (82) of the coupling rod (74) and the coupling rod (74) connected in an articulated manner in its second end area (88) to the first bell crank (38) and further comprising the step of connecting (204) the steering actuator (46) in an articulated manner by means of a sixth pivot joint (96) to the second bell crank (76) or the coupling rod (74),

17. The method according, to claim 14, further comprising the step of connecting (206) the steering actuator (46) in an articulated manner with a thud ball joint (57) to the steering rod (30).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Further embodiments result from the exemplary embodiments explained in detail in the figures.

[0040] FIG. 1 shows a first exemplary embodiment of the steering system integrated in a vehicle.

[0041] FIG. 2 shows another exemplary embodiment of the steering system.

[0042] FIG. 3 shows another exemplary embodiment of the steering system.

[0043] FIG. 4 shows a top view of an exemplary embodiment of the steering system.

[0044] FIG. 5 shows a hydraulic steering system according to the prior art.

[0045] FIG. 6 shows the steering system from FIG. 5 in top view.

[0046] FIG. 7 shows the steps of the method according to an exemplary embodiment.

DETAILED DESCRIPTION OF THE INVENTION

[0047] FIG. 1 shows a vehicle 10 in a side view, which has a steering system 11 and a vehicle frame 12, from which other components of the vehicle are suspended in addition to the components shown and which represents the basic structure of the vehicle. The vehicle frame 12 is also known as the chassis. The vehicle frame 12 extends along a longitudinal direction 13 of the vehicle 10.

[0048] On vehicle frame 12, an axle 14 is connected at one end to vehicle frame 12 via a joint not shown. The end 15 of the axle 14, visible here in side view, is thus mounted so that it can move in a vertical direction 16 relative to the vehicle frame 12. The shown end 15 of the axle 14 is supported by a leaf spring 18 or an air spring 20. On the axle 14, a steering knuckle 22 is connected to a pivot bearing, which can be rotated around an axle that runs in the vertical direction 16. A wheel (not shown) of a front axle of the vehicle 10 can be attached to the steering knuckle 22. An articulated lever 24 is firmly connected to the steering knuckle 22.

[0049] The articulated lever 24 is connected to an end area 29 of a steering rod 30 via a joint 26, which is a second ball joint 28. In its opposite end area 32, the steering rod 30 is connected to a fist bell crank 38 via a further joint 34, Which is a first ball joint 36 in an articulated manner. The steering rod 30 has a length L that is more than twice as long as a bell crank length l of bell crank 38. Steering rod 30 and first bell crank 38 are part of a steering linkage 37.

[0050] The first bell crank 38 is connected to the vehicle frame 12 opposite the end area 39 of the bell crank, which is also called first end area 39 of the bell crank 38 and at which the bell crank 38 is connected to the steering rod 30, in another end area 40 of the bell crank 38, which is also called second end area 40 of the bell crank 38, via another joint 42, which is a second pivot joint 44. The position at which the bell crank 38 is articulated to the vehicle triune corresponds to a mounting position 45 for a steering gear or steering column lever of a hydraulic steering system which, however, is not used here in particular.

[0051] Furthermore, an electromechanical steering actuator 46 is pro died, which is a linear actuator 48, in particular a spindle drive 50. The steering actuator 46 comprises an electric motor 52, which drives a spindle 54, which is connected to a piston 56 and moves it along an actuation direction 58. A coupling point 62 is provided on the steering rod 30 in a central area 60, to which the piston 56 is connected via a third ball joint 57. The coupling point 62 corresponds to a point of application 63 of the steering actuator 46 on the steering rod 30 of the steering linkage 37, i.e. a point at which the steering actuator 46 transmits a force to the steering linkage 37. The point of application 63 is therefore spaced from the second end area 40 of the bell crank 38. Furthermore, the steering actuator 46 is connected at the other end to a mounting plate 66 on the vehicle frame 12 via a joint 64, which is a fourth ball joint 65. The mounting plate 66 is located further to the front of the vehicle 67 than mounting position 45.

[0052] Furthermore, a steering column 68 and a steering wheel 70 are also provided. A rotational movement of the steering wheel 70 is transmitted to the actuator 46 via the steering column 68 and this rotational movement is converted into a movement in the actuation direction 58. This moves the steering rod 30 so that steering the steering knuckle 22 is possible.

[0053] FIG. 2 shows an alternative exemplary embodiment where the steering actuator 46 is not directly connected to the steering rod 30. Rather, a coupling rod 74 and a second bell crank 76 are provided in addition tri the first bell crank 38. The second bell crank 76 and the coupling rod 74 are also part of the steering linkage 37. The electric actuator 46 is here connected to the second bell crank 76.

[0054] In detail, the second bell crank 76 is connected to the vehicle frame 12 at a first end area 77 via a joint 78, which is a third pivot joint 80. Furthermore, the coupling rod 74 is connected in a first end area 82 of the coupling rod 74 via a joint 84, which is a fourth pivot joint 86, to the second bell crank 76 in the second end area 85 of the second bell crank 76. On the other hand, the coupling rod 74 is connected to the first bell crank 38 in a second end area 88 of the coupling rod 74 via a joint 90, which is a fifth pivot joint 92. The remaining connections between the first bell crank 38 and the steering rod 30 and the steering rod 30 with the articulated lever 24 are identical to FIG. 1.

[0055] However, the steering actuator 46 is non connected here via a joint 94, which is a sixth on joint 96, to the second end area 85 of the second bell crank 76. This decouples movements of the axle 14 from the actuator 46 to such an extent that the joint 64, by means of which the actuator 46 is connected to the vehicle frame 12, is designed here as the first pivot joint 98. Essentially, the piston 56 thus moves along the actuation direction 58 almost parallel to the vehicle frame 12.

[0056] FIG. 3 shows another alternative exemplary embodiment, in which the steering actuator 46 is also not directly connected to the steering rod 30 as in the exemplary embodiment of FIG. 1. Here, as in FIG. 2, the steering linkage 37 comprises the first bell crank 38, the second bell crank 76, the coupling rod 74 and the steering rod 30. The electric drive 46 is connected to the second bell crank 76. Accordingly, the exemplary embodiment in FIG. 3 is similar to the exemplary embodiment in FIG. 2.

[0057] In contrast to FIG. 2, however, in FIG. 3 the second bell crank 76 is connected to the vehicle frame 12 in a central area 79 of the second bell crank 76 via a joint which corresponds to the third pivot joint 80. Furthermore, in FIG. 3, the steering actuator 46 is now connected to the first end area 77 of the second bell crank 76 via a joint 94 corresponding to the sixth pivot joint 96.

[0058] Steering actuator 46 and the first end area 77 of the second bell crank 46 now lie in or above a plane described by the vehicle frame 12. The second bell crank 76 non exerts a force on the second bell crank is the point of application 63, depending on a force applied by the steeling actuator 46, so that the second bell crank rotates around the pivot point of the third pivot joint 80 and transmits its movement via the coupling rod 74 to the first bell crank 38 and then to the steering rod 30. Here, too, the point of application 63 is therefore at a distance from the second end area 40 of the first bell crank 38.

[0059] As in FIG. 2, also in FIG. 3 the coupling rod 74 in the first end area 82 of the coupling rod 74 is connected to the second bell crank 76 in the second end area 85 of the second bell crank 76 via a joint 84, which corresponds to the fourth pivot joint 86. Furthermore, the coupling rod 74 is connected in the end area 88 of the coupling rod 74 to the first bell crank 38 via a joint 90, which is a fifth pivot joint 92. The remaining connections between the first bell crank 38 and the steering rod 30 as well as the steering rod 30 and the articulated lever 24 are identical to FIGS. 1 and 2.

[0060] FIG. 4 shows a top view of the vehicle 10 with the steering system 11 according to the exemplary embodiment of FIG. 1. Identical reference numerals correspond to identical features. Accordingly the steering actuator 46 can be recognized, which is connected to the steering rod 30 in a central area 60 of the steering rod 30 in a coupling point 62. Furthermore, the steering rod 30 is connected to the first bell crank 38 in an articulated manner and at a distance from the vehicle frame 12. The steering rod 30 is connected to an articulated lever 24 in order to steer one wheel 100. The steering movement of one wheel 100 is transmitted to another wheel 100 of the same axle via knuckle arm 102 and a track rod 104.

[0061] FIGS. 5 and 6 show the prior art in each case with a vehicle 150, which has a hydraulic steering system 152. On one axle 14 of the vehicle 150, a steering knuckle 22 is connected to a pivot bearing, which can be rotated about an axis extending in the vertical direction 16. An articulated lever 24 is firmly connected to the steering knuckle 22. The hydraulic steering system 152 has a steering linkage 154 which comprises a steering rod 30. The articulated lever 24 is connected to the steering rod 30 via a joint 26. The steering rod 30 is in turn connected to a steering column lever 156 which is connected to a steering actuator 158. The steering actuator 158 comprises a sleeting gear 160, wherein the steering gear 160 is connected to the vehicle frame 12 of the vehicle 150 at a mounting position 45. A rotary motion of the steering wheel 70 is transmitted to the steering actuator 158 via the steering column 68 and this rotary motion is converted into a rotary motion about an axis 162 extending perpendicularly to the image plane. A force of the steering actuator 158 is thus transmitted to the steering linkage 154 in or at a point of application 164, with the point of application 164 being located at the end 166 of the steering column lever 156, so that the latter pivots about the axis 162 by the force of the steering actuator 158 and thus moves the steering column 30.

[0062] FIG. 7 shows the steps of the method for equipping a vehicle 10 with the steering system 11. In a step 200, a mounting position 45 for a steeling, gear or a steering column lever on the vehicle frame 12 is identified. In step 202, the first bell crank 38 is then connected to the vehicle frame 12 at mounting position 45 or in the area of mounting position 45 in an articulated manner.

[0063] In step 204, a steering actuator 46 is articulated to the vehicle frame 12, wherein preferably this connection is carried out further towards a vehicle front 67 than the mounting position 45. In a step 206, the steering actuator 46 is then connected in an articulated manner, in particular by means of a sixth pivot joint 96, to the second bell crank 76 or the coupling rod 74, or in an articulated manner, in particular by means of a third ball joint 57, to the steering rod 30.

LIST OF REFERENCE NUMERALS (PART OF THE DESCRIPTION)

10 Vehicle

[0064] 11 Steering system
12 Vehicle frame
13 Longitudinal direction

14 Axle

[0065] 15 End of the axle
16 Vertical direction
18 Leaf spring

20 Air Spring

[0066] 22 Steering knuckle
24 Articulated lever

26 Joint

[0067] 28 Second ball joint
32 End area

30 Steering rod

[0068] 32 End area
34 Further joint
36 First ball joint
37 Steering linkage
38 First bell crank
39 End area
40 End area
42 Further joint
44 Second pivot joint
45 Mounting position
46 Electromechanical steering actuator
48 Linear actuator
50 Spindle drive

52 Motor

54 Spindle

56 Piston

[0069] 57 Third ball joint
58 Actuation direction
60 Central area
62 Coupling point

64 Joint

[0070] 65 Fourth ball joint
66 Mounting plate
67 Front side of vehicle
68 Steering column
70 Steering wheel

74 Coupling rod

[0071] 76 Second bell crank
77 First end area

78 Joint

[0072] 79 Central area
80 Third pivot joint
82 First end area

84 Joint

[0073] 85 Second end area
86 Fourth pivot joint

88 Second end

90 Joint

[0074] 92 Fifth pivot joint

94 Joint

[0075] 96 Sixth pivot joint
98 First pivot joint

100 Wheel

102 Knuckle arm

104 Track rod

150 Vehicle

[0076] 152 Hydraulic steering system
154 Steering linkage
156 Steering column lever
158 Steering actuator
160 Steering gear

162 Axis

[0077] 164 Point of application
166 End of the steering column lever

200 Step

202 Step

204 Step

206 Step