DEVICE FOR ADJUSTING CAMBER AND/OR TOE OF A VEHICLE WHEEL

Abstract

A device for adjusting camber and/or toe of a vehicle wheel of a motor vehicle, includes a wheel carrier including a wheel-side carrier part, an axle-side guide part and rotary parts arranged between the wheel-side carrier part and the axle-side guide part, the rotary parts being supported on a common bearing site for rotation relative to each other about a rotation axis, the wheel-side carrier part being rotatable about said rotation axis about an instantaneous center of rotation for toe or camber adjustment of the vehicle wheel and supporting a brake caliper interacting with a brake disc of the vehicle wheel; and a torque bridge configured as a torque transmission element which supports the wheel-side carrier part on the axle-side guide part when a braking moment acts on the wheel-side carrier part during a braking process, and which when supporting the wheel-side carrier part on the axle-side guide part generates a directed force component with which the wheel-side carrier part is impingable.

Claims

1-13. (canceled)

14. A device for adjusting camber and/or toe of a vehicle wheel of a motor vehicle, comprising: a wheel carrier including a wheel-side carrier part, an axle-side guide part and rotary parts arranged between the wheel-side carrier part and the axle-side guide part, said rotary parts being supported on a common bearing site for rotation relative to each other about a rotation axis, said wheel-side carrier part being rotatable about said rotation axis about an instantaneous center of rotation for toe or camber adjustment of the vehicle wheel and supporting a brake caliper interacting with a brake disc of the vehicle wheel; and a torque bridge configured as a torque transmission element which supports the wheel-side carrier part on the axle-side guide part when a braking moment acts on the wheel-side carrier part during a braking process, and which when supporting the wheel-side carrier part on the axle-side guide part generates a directed force component with which the wheel-side carrier part is impingable.

15. The device of claim 14, wherein the torque transmission element is constructed as at least one coupling rod, which is subjectable to tensile and compressive forces.

16. The device of claim 14, wherein the torque transmission element is constructed for articulate connection on a wheel-side attachment site on the wheel-side carrier part and on an axle-side attachment site on the axle-side guide part.

17. The device of claim 16, wherein the wheel-side attachment and the axle-side attachment site of the torque transmission element are positioned so that the torque transmission element is seizable between the carrier part and the guide part.

18. The device of claim 14, wherein during the braking process the torque transmission element generates a counter moment with which a reaction moment, resulting from a total vehicle wheel moment and being conducted from the vehicle wheel to the rotary parts is reducible.

19. The device of claim 18, wherein the total vehicle wheel moment essentially consists of a longitudinal moment, which is generated by a longitudinal braking force component, which acts on a wheel center and of a vertical moment, which acts on the vehicle wheel and is generated by a brake pitching compensation.

20. The device of claim 14, wherein the torque transmission element includes at least one coupling member, which is solely subjectable to tensile forces but not to compressive force.

21. The device of claim 20, wherein the torque transmission element is constructed as a chain or a pull strap.

22. The device of claim 14, wherein a wheel center of the vehicle wheel and the instantaneous center of rotation are spaced apart from each other by a lever arm.

23. The device of claim 16, wherein the wheel-side attachment site and the axle-side attachment site of the torque transmission element are spaced apart from the instantaneous center of rotation in three spatial directions.

24. The device of claim 16, wherein the wheel-side attachment site and the axle-side attachment site of the torque transmission element when viewed in vehicle transverse direction are offset from the instantaneous center of rotation inwards by respective distances.

25. The device of claim 16, wherein the wheel-side attachment site and the axle-side attachment site when viewed in vehicle longitudinal direction are positioned before or behind the instantaneous center of rotation by respective distances.

26. The device of claim 16, wherein the wheel-side attachment site and the axle-side attachment site are offset from the instantaneous center of rotation (MP) in vehicle vertical direction by respective distances.

27. The device of claim 14, wherein in the wheel-side rotary part a wheel bearing is integrated.

28. The device of claim 14, wherein the carrier part is supported in the wheel-side rotary part via a bearing site.

29. The device of claim 28, wherein in the wheel bearing of the wheel carrier a wheel hub section of a wheel flange which carries the vehicle wheel is rotatably supported.

30. The device of claim 29, wherein the carrier part is arranged radially outside the wheel-side rotary part.

31. The device of claim 30, wherein the carrier part is supported on the wheel-side rotary part via a radially inner bearing site.

32. The device of claim 29, wherein the wheel bearing is configured demountable and includes a radially inner bearing housing and a demountable radially outer bearing housing, said demountable outer bearing housing being mounted on an outer circumference of the wheel hub or an inner circumference of the rotary part.

33. The device of claim 32, wherein the for example by press fit or by screwing

34. The device of claim 29, wherein the wheel-side rotary part directly forms the radially outer bearing housing of the wheel bearing, and wherein radially inward of the rotary part, which forms the outer bearing housing a wheel hub section of a wheel flange, which carries the vehicle wheel is rotatably supported.

Description

[0021] It is shown in:

[0022] FIG. 1 a schematic representation of the device for adjusting toe and camber angle of a motor vehicle wheel;

[0023] FIG. 2 in a halve section the upper half of the device in a present embodiment;

[0024] FIG. 3 a full sectional view of the device with mounted vehicle wheel;

[0025] FIG. 4 a sectional view along the sectional plane I-I of FIG. 3;

[0026] FIGS. 5a and 5b the wheel carrier respectively in a view from above and in a view from behind; and

[0027] FIGS. 6 to 9 respectively schematic representations of different coupling arrangements between the wheel-side carrier part and the axle-side guide part of the wheel carrier.

[0028] In order to facilitate understanding of the invention FIG. 1 shows a strongly schematic representation of a wheel carrier 1 of a vehicle wheel 13 known from the state of the art, which is not part of the invention.

[0029] The wheel carrier 1 has a carrier part 3 in which a wheel flange 5 is rotatably supported with its hub section 7 in a wheel bearing 12. On the wheel flange 5 a brake disc 11 and a vehicle wheel 13 is mounted with its wheel rim. The brake disc 11 together with a brake caliper 15 mounted on the carrier part 3 is a part of the brake system. Extending through the wheel carrier 1 is an articulated shaft which drives the vehicle wheel 13 and on whose constant velocity joint (only shown in FIGS. 2 to 4 with reference numeral 9) an also not shown central screw is screwed, with which the wheel bearing 12 is clamped via the wheel hub 5 and the cons.sub.tant velocity joint 9.

[0030] The wheel carrier 1 also has a guide part 17 on which in FIG. 1 exemplarily a control arm 19 of the wheel suspension is articulately connected. Between the carrier part 3 and the guide part 17 two rotary parts 21, 23 are provided as actuating elements. The rotary part 21 is rotatably connected with the carrier part 3 at a bearing site 32 so as to define a rotary part axis 20. The rotary part 23 is connected with the guide part 17 at a bearing site 35 and defines a rotation axis 22. In FIG. 1 the two rotary parts 21, 23 are connected with each other via even, slanted surfaces 25, 27 in a sliding bearing and are rotatable relative to each other via a rotation axis 24. The rotation axis 24 in FIG. 1 is oriented perpendicular to the slanted surfaces 25, 27 and is oriented inclined at a defined angle relative to the rotation axis 22 of the axle-side rotary part 23.

[0031] In FIG. 1 the rotary part axis 20 coincides with the wheel axis. However, thereto the rotary part 21 may alternatively not be arranged coaxial to the wheel axle as shown in FIG. 1 but the rotary part axis 20 and the wheel axle can be arranged inclined relative to each other.

[0032] On the carrier part 3 as well as on the guide part 17 a respective electric actuating motor 29 is provided, which is drivingly connected with the rotary parts 21, 23 via gear drives 30. By means of the actuating motors the two rotary parts 21, 23 can be rotated in the same direction or opposite directions in both directions of rotation, whereby the carrier part 3 performs a pivot movement or tumbling movement relative to the guide part 17 about an instantaneous center of rotation MP (FIGS. 2 to 5) and thus correspondingly changes the toe angle and/or the camber angle of the vehicle wheel 13.

[0033] In FIG. 1 thus the bearing site 32 is formed between the wheel-side carrier part 3 and the wheel-side rotary part 21, the bearing site 31, consisting of the two slanted surfaces 25, 27 between the two rotary parts 21, 23 and a further bearing site 35 is formed between the axle-side rotary part 23 and the guide part 17.

[0034] FIG. 2 shows the wheel carrier 1 according to the invention. In contrast to FIG. 1 the two rotary parts 21, 23 are not in contact with each other via even, slanted surfaces 25, 27 to define the slanted rotation axis 24 but are supported on a rotary bearing site 31.

[0035] In addition in FIG. 2 the wheel bearing 12 is no longer directly integrated in the wheel-side carrier part 3 but rather indirectly in the wheel-side rotary part 21. In FIG. 2 the bearing outer paths and the bearing inner paths of the wheel bearing 12 are purely exemplarily shown in the inner circumference of the wheel-side rotary part 21 and directly in the outer circumference of the hub section 7 of the wheel flange 5. Correspondingly in FIG. 2 the wheel-side rotary part 21 has the additional function of an outer bearing housing of the wheel bearing 12. On the outer circumference of the wheel-side rotary pat 21 the carrier part 3 is supported in vehicle transverse direction y outside on the wheel-side rotary part 21 via a bearing site 43 radially outward. The bearing site 43 has to be configured so that tilting moments can be absorbed.

[0036] In contrast to FIG. 2 in a technical implementation the wheel bearing 12 can be configured demountable, i.e., with a radially outer bearing housing, which is demountable, i.e., it is for example mounted on the outer circumference of the rotary part 21 in press fit or by screwing, and/or with a radially inner bearing housing, which can be mounted on the outer circumference of the wheel hub 5.

[0037] As can be further seen from FIG. 2 the bearing site 43 and the rotary bearing site 31 are purely exemplarily formed on axially opposing sides of the rotary part 21, wherein there between a gearwheel section 47 is positioned which is a component of the gear drive 30 (FIG. 1).

[0038] In analogy to the wheel-side carrier part 3 the axle-side guide part 17 is supported in a rotary bearing 51 radially outward on the axle-side rotary part 23. Further inwards in vehicle transverse direction y a further gearwheel section 55 is exemplarily formed on the outer circumference of the axle-side rotary part 23, which further gearwheel section is also a part of the gear drive 30. The gearwheel section 55 of the axle-side rotary part 23 is positioned in an annular space 57, which is delimited outward in vehicle transverse direction y by the rotary bearing 51 and inward by a ring gasket 59, which is arranged between the guide part 17 and the axle-side rotary part 23.

[0039] According to the invention the wheel-side carrier part 3 carries—beside for example an electronic parking brake—only the brake caliper 15 and the drive motor 29 of the wheel-side rotary part 21, but no longer the wheel bearing 12. As a result the rotary bearing 43, which is arranged between the carrier part 3 and the wheel-side rotary part 21, is removed from the force flux. As a result with regard to the occurring forces only three bearing sites are still connected in series, i.e., the wheel bearing 12, the rotary bearing 31 and the support bearing 51, but not the bearing site 43 on which the carrier part 3 is supported on the wheels-side rotary part 21. Therefore the bearing site 43 seated on the wheel-side rotary part 21 can be configured smaller because the wheel forces and moments acting at this location are much smaller. As a result of the absence of the bearing site 43 from the force flux also the camber stiffness of the bearing group increases, which makes it possible that the remaining bearings, i.e., the wheel bearing 12, the rotary bearing 31 and the support bearing 51, can be configured smaller compared to the state of the art while retaining the same camber stiffness.

[0040] In FIG. 2 a coupling rod 61 is mounted between the carrier part 3 and the guide part 17. The coupling rod acts as torque transmission element via which moments, in particular a braking moment and/or motor moments of the outer rotary drive 29, can be transmitted from the carrier part 3 to the guide part 17, i.e., while bridging the axle-side and wheel-side rotary arts 21, 23. The coupling rod 61 is for example arranged radially outside a circumferential rubber sleeve 63, which seals the rotary parts 21, 23 and their bearing sites against dirt.

[0041] The coupling rod 61 is positioned with its attachment sites K1 and K2 on the wheel-side carrier part 3 and on the axle-side guide part 17 so that in a braking process a directed force component F (FIG. 3 or 4) results with which the wheel-side carrier part 3 can be impinged.

[0042] During the braking process forces and moments act on the vehicle wheel 13, of which in FIG. 4 exemplarily a longitudinal braking force component F.sub.a,x is highlighted. The braking longitudinal force component F.sub.B,X acts on the wheel center RM, which in FIG. 4 is spaced apart from the instantaneous center of rotation MP by a lever arm, whereby a longitudinal moment M.sub.B,x is generated which pushes the vehicle wheel 13 in the direction of the toe-out. The longitudinal moment M.sub.B,X is transmitted to the wheel-side rotary part 21 via the hub section 7 of the wheel flange 5 and via the wheel bearing 12.

[0043] In addition during the braking process an upward oriented vertical braking force component F.sub.B,Z acts on the vehicle wheel 13 (rear wheel) due to the pitching compensation, by which a vertical moment M.sub.B,Z is generated, which leads to a change of the camber moment on the actuator.

[0044] These moments M.sub.B,X and M.sub.B,Z, exemplarily highlighted in FIG. 3 or 4, add up (potentially with other moments occurring during the braking process) to a total vehicle wheel moment M.sub.Tire, which acts on the rotary parts 21, 23 as reactive moment. The total vehicle wheel moment M.sub.Tire can be, but does not have to be, identical with the reaction moment, which directly acts on the rotary drive of the rotary parts 21, 23. Rather the reaction moment can be different from the total vehicle wheel moment M.sub.Tire. This depends for example on the actual rotary positions of the rotary parts, on the actual position of the slanted, even plane formed between the rotary parts and/or the actuator transmission ratio.

[0045] In order to prevent the reaction moment acting on the rotary parts 21, 23 from leading to an inadvertent rotary movement of the rotary parts 21, 23 in the state of the art a corresponding counter control of the gear rive 30 of the wheel-side and/or the axle-side rotary part 21, 23 is performed.

[0046] In contrast thereto according to the invention the total vehicle wheel moment M.sub.Tire is converted in the braking process into the directed force component F by means of the coupling rod 61, with which force component the coupling rod 61 acts on the wheel-side carrier part 3 during the braking process, i.e., the wheel-side carrier part 3 is impinged on the wheel-side attachment site K2 of the coupling rod 61 with the directed force component F, whereby a total counter holding moment M.sub.couple is generated, which counteracts the total vehicle wheel moment M.sub.Tire so as to minimize the reaction moments on the rotary parts 21, 23.

[0047] The exact position of the attachment sites K1, K2 of the coupling rod 61 depends on the geometric conditions of the wheel carrier and can be calculated by using the technical literature (for example the textbook “joints and universal shafts” by Schmelz, Seherr-Thoss, Aucktor). For example the positions of the attachment sites K1, K2 of the coupling rod 61 can be determined so that in the complete movement space of the vehicle wheel 13, i.e., for example in a tow angular range of +/−6.5 and a camber angular range between −5 and +2.5 the remaining moment that acts during the bring process in the rotary parts 21, 23 is as small as possible. The remaining moment is calculated from the difference between the counter moment M.sub.couple exerted by the coupling rod 61 and the above-mentioned total vehicle wheel moment M.sub.Tire, i.e., while taking an actuator transmission ratio in the operating point of the respective force component into account.

[0048] Important for the position of the coupling rod attachment sites K1, K2 are their distances to the instantaneous center of rotation MP in the spatial directions x, y, z as illustrated in FIGS. 5a and 5b. Accordingly when viewed in vehicle transverse direction y the attachment sites K1, K2 are positioned at distances □y.sub.1, □y.sub.2 within the instantaneous center of rotation MP. In addition the attachment sites K1, K2 are when viewed in vehicle longitudinal direction x positioned in front of and behind the instantaneous center of rotation MP by distances □y.sub.1, □y.sub.2. In the vehicle vertical direction z the attachment sites K1, K2 are positioned outside (i.e., in FIG. 5b above) the instantaneous center of rotation MP. As can be further seen from FIGS. 5a and 5b the attachment sites K1 and K2 of the coupling rod 61 are when viewed in vehicle transverse direction y, not oriented aligned with each other but are spaced part form each other in vehicle longitudinal direction x by a distance.

[0049] The following FIGS. 6 to 9 show very schematic representations, which illustrate further variants of the torque transmission element 61. Accordingly according to FIG. 6 not only a single coupling rod may be provided but rather overall up to four coupling rods which are arranged distributed over the circumference of the wheel axle and are attached on wheel-side and axle-side coupling sites K1, K2. The coupling sites K1 and K2 are all arranged when viewed in vehicle transverse direction y on a circular line 65 which for example represents exemplarily the outer contour of a gimbal of a universal joint which requires significantly more mounting space compared to the coupling rods, as it is for example arranged in DE 10 2009 058 489 A1 between the wheel-side carrier part and the axle-side guide part 17.

[0050] In FIG. 7 exemplarily overall three coupling rods 61 are provided, two of which extend straight, while the third coupling rod 61 for example has an S-bend due to mounting space conditions. In FIG. 8 only one coupling rod 61 is shown whose position substantially corresponds to the coupling rod position in FIGS. 2 to 5. In FIG. 9 the torque transmission element 61 is not formed by a coupling rod but rather by coupling members, for example chains or pull straps, which can only be subjected to tensile stress.