Wheel suspension for a vehicle wheel of a two-track vehicle

Abstract

The invention relates to a wheel suspension for a vehicle wheel (HR) of a two-track vehicle, with a multi-link assembly which, with reference to a wheel center of the vehicle wheel (HR), has upper and lower control arms (7, 9, 11, 13) and a tie rod (15) which are articulated to the vehicle body via body-side bearings (16, 17) and to the wheel carrier (21) of the vehicle wheel (HR) via wheel carrier-side bearings (18, 19), wherein one of the control arms (7, 9, 11, 13) is provided with a camber adjustment, wherein one of the control arm bearings (17, 19) of a control arm (7) is assigned a camber adjustment actuating unit (27), by means of which the control arm (7) is adjustable by an actuating travel in the transverse direction (y) of the vehicle, whereby camber adjustment of the vehicle wheel (HR). According to the invention, one of the control arms (7, 9, 11, 13) of the multi-link assembly is a front upper control arm (7) equipped with camber adjustment.

Description

[0001] The invention relates to a wheel suspension for a vehicle wheel of a two-track vehicle according to the preamble of claim 1.

[0002] Such a wheel suspension has a multi-link system which, with reference to a wheel center of the vehicle wheel, consists of upper and lower control arms as well as a tie rod, which are articulated to the vehicle body via body-side bearings and to the wheel carrier of the vehicle wheel via wheel carrier-side bearings.

[0003] Precise positioning of the vehicle wheels relative to the road is essential for safe and comfortable vehicle handling. The positions of the kinematic points of the suspension, located at the body-side and wheel carrier-side control arm bearings, play a crucial role in this. These kinematic points allow direct influence on the wheel position parameters and their changes over the suspension travel. The two most important wheel position parameters are the toe and camber angles. To ensure the correct wheel position parameters in a real-world suspension setup, these must be adjusted using actuators. These actuators are also necessary to achieve different vehicle ride heights with identical wheel position parameters. Furthermore, they compensate for manufacturing tolerances.

[0004] However, there is a risk that the adjustment units may negatively affect the wheel alignment parameters via the wheel path. For five-link axles or partially separated double wishbone axles with a front tie rod, which have toe and camber adjustment, the toe angle is often adjusted via the tie rod and the camber angle via the rear lower control arm.

[0005] With a five-link axle or a partially separated double wishbone axle with a front-mounted tie rod (i.e., the tie rod is in front of the wheel center in the direction of travel), which features toe and camber adjustment and where the toe angle is adjusted via the tie rod and the camber angle via the rear lower control arm, adjustments to the static toe and camber values, in the current state of the art, also lead to an undesirable change in the toe gradient. This is due to kinematic relationships. Thus, in unfavorable cases, the toe angle can change during compression or rebound in such a way that the handling tends towards oversteer and therefore becomes unstable. Furthermore, tire wear can be negatively affected. Another disadvantage arises as soon as the axle adjustments are made asymmetrically.In this situation, the wheels steer in the same direction when the suspension compresses on the same side, resulting in a yaw movement (steering motion) in the vehicle when driving over an obstacle. This can occur when tolerances in the axle components are compensated for, or when the vehicle is slightly tilted relative to the road surface and the static toe and camber values ​​are set relative to the road surface.

[0006] Furthermore, the toe angle can increase significantly over the suspension travel when the axle alignment is adjusted, so that uneven suspension compression can also result in a steering effect of the axle. With active suspension systems, this can lead to significant deviations in handling characteristics.

[0007] Another disadvantage is that in special events, such as a sideways slide against a curb, the lower rear of the handlebars is subjected to very high forces. The camber adjustment at this point, which uses an elastic screw system to allow for the reuse of the axle adjusting screw, must therefore be robustly designed. This results in increased weight and higher torque requirements for customer service and production.

[0008] From US Patent 5,398,411 A, a wheel suspension is known in which a wheel guidance element comprises a first mounting section that is pivotably connected to either a vehicle body or an axle by a connecting element, and a second mounting section that is integrally connected to the first mounting section and to the other of the vehicle body and axle. The first mounting section is provided on its outer surface with a pair of parallel cam guides for adjusting the relative mounting position between the first mounting section and an axle.

[0009] From WO 2016 / 041 706 A1, a track rod or steering rod for a vehicle is known, comprising a tube which, in an axially extending tube end region, has an internal thread that is open in a first direction of rotation and at least one axially extending slot, as well as an adjusting sleeve screwed into the tube end region and extending out of it with an actuation area. By rotating the adjusting sleeve, an axial adjustment movement of the tube is effected relative to a joint.

[0010] From EP 2 783 947 B1, an adjustment device for adjusting a wheel control arm or a tie rod on a motor vehicle is known. From DE 10 2014 226 536 A1, a control arm for a wheel suspension of a motor vehicle is known. The control arm comprises a base element, an attachment element, and at least one fastening element. In the event of a mechanical load on the control arm, the base element and the attachment element move relative to each other. From DE 10 2015 101 438 A1, a spacer assembly adjustable by a cam is known, which has a bushing. The spacer assembly adjustable by the cam further comprises a screw which is arranged at least partially in the cam bore along a first cam axis. The screw engages with the cam bore in such a way that a rotation of the screw about the first cam axis causes the cam in the bushing to rotate about the bushing axis.

[0011] Further wheel suspensions are known from DE 10 2014 201 876 A1, from DE 44 37 661 A1, from DE 41 15 110 A1 and from EP 1 932 692 A1.

[0012] The object of the invention is to provide a wheel suspension for a vehicle wheel of a two-track vehicle in which camber adjustment can be carried out without negatively influencing the driving behavior of the vehicle.

[0013] The problem is solved by the features of claim 1. Preferred embodiments of the invention are disclosed in the dependent claims.

[0014] The invention relates to a wheel suspension for a vehicle wheel of a two-track vehicle with a multi-link system. The multi-link system comprises upper and lower control arms and a tie rod with respect to the wheel center of the vehicle wheel. These are articulated to the vehicle body via body-side bearings and to the wheel carrier of the vehicle wheel via wheel carrier-side bearings. One of the control arms is equipped with a camber adjustment mechanism, in which a bearing of the control arm has a camber adjustment actuator. With the aid of the camber adjustment actuator, the control arm can be adjusted at the factory during axle alignment by a certain amount of travel in the transverse direction of the vehicle, thereby adjusting the camber of the vehicle wheel.According to the characterizing part of claim 1, the following measure is taken to avoid a negative influence on the vehicle's handling due to the camber adjustment: A front upper link of the multi-link suspension is provided with camber adjustment.

[0015] The camber adjustment according to the invention is therefore transferred to the front upper control arm. This control arm has a high sensitivity with regard to the static camber value. Furthermore, during axle alignment, the control arm is preferably moved not only horizontally, but also at a very specific angle, since the vertical position of the kinematic points of this control arm also results in a high sensitivity to the toe gradient. The tie rod adjustment point for setting the toe angle is also moved at a defined angle.

[0016] By applying the invention, an additional adjustment to correct the toe gradient (for example, height-adjustable toe gradient adjustment or a second camber adjustment) can be dispensed with. Furthermore, an almost complete compensation of the effects on the toe curve (symmetrical driving behavior) can be achieved. Additionally, reduced tire wear and lower forces on the actuating unit result.

[0017] In a preferred embodiment, the tie rod of the multi-link suspension, in particular its wheel carrier-side tie rod bearing, can be arranged in front of the wheel center in the direction of travel. The tie rod can be provided with a toe adjustment mechanism in which an actuating unit is assigned to one of the tie rod bearings, by means of which the tie rod can be adjusted by a tie rod adjustment path in the transverse direction of the vehicle, thereby adjusting the toe of the vehicle wheel.

[0018] In a specific embodiment, the multi-link suspension can have a rear upper link in addition to the front upper link in an upper link plane. Preferably, the multi-link suspension is part of a five-link axle in which a lower front wishbone, acting as a support link for a suspension spring, and a lower rear wishbone are arranged in a lower link plane. Alternatively, the multi-link suspension can be part of a double wishbone axle with a split upper link plane, in which a support link for a suspension spring is designed as a triangular link in the lower link plane, and no other lower link is present. The adjusting unit can have a cam track, particularly a linear one, for camber adjustment and / or toe adjustment. The respective control arm bearing and tie rod bearing can be adjusted along the cam track.The cam track of the actuating unit is preferably not aligned with a horizontal plane, but rather forms an angle of inclination with the horizontal plane. The exact angles for the best possible reduction of the effects on the track curve must be determined depending on the specific kinematics.

[0019] For camber adjustment, it is preferred that the cam track of the camber adjustment unit extends obliquely upwards inwards in the transverse direction of the vehicle at an angle of inclination between 0° and 45° with the horizontal plane. For toe adjustment, on the other hand, it is preferred that the cam track of the toe adjustment unit extends obliquely upwards inwards in the transverse direction of the vehicle at an angle of inclination between 0° and 30° with the horizontal plane.

[0020] Examples of implementation are described below with reference to the attached figures.

[0021] They show: Fig. Figures 1 to 5 show different views of a five-link axle of a two-track vehicle.

[0022] In Fig. Figure 1 shows the right side of a five-link axle of a two-track vehicle. The left side of the five-link axle, not shown, is a mirror image with respect to a longitudinal center plane of the vehicle. The Fig. The five-link axle shown in Figure 1 is simplified for ease of understanding of the invention by omitting chassis components that are not essential for its operation. Accordingly, the five-link axle comprises a subframe 1, which is constructed in a frame-like manner from longitudinal members 3 and transverse members 5. Furthermore, the wheel suspension has a five-link assembly, which includes two control arms 7, 9 in an upper link plane and two control arms 11, 13 in a lower link plane. The five-link assembly also includes a tie rod 15, which is articulated in the direction of travel FR in front of the wheel center of the vehicle wheel. The control arms 7, 9, 11, 13 and the tie rod 15 are articulated to the vehicle body via body-side control arm bearings 17 and tie rod bearings 16, and to a wheel carrier 21 of the vehicle wheel HR via wheel carrier-side control arm bearings 19 and a wheel carrier-side tie rod bearing 18. The rear lower control arm 13 forms in the Fig. 1 a support arm on which a suspension spring 23 supporting the vehicle body is supported.

[0023] The body-side and wheel carrier-side bearings 16 to 19 of the tie rod 15 and the control arms 7 to 13 are each designed as rubber-metal sleeve bearings, consisting of a sleeve-shaped bearing core, a coaxial outer sleeve, and an intermediate elastomer body. A bearing bolt 25 extends through the sleeve-shaped bearing core. This bolt projects axially from both sides of the sleeve-shaped bearing core with its bolt ends, each of which is screwed to a body-side / wheel carrier-side bracket.

[0024] The bearing bolt 25 of the tie rod and control arm bearing defines a pivot axis about which the control arms 7 to 13 and the tie rod 15 can pivot.

[0025] In the Fig. 2 shows the five-link suspension in a front view. As seen from the Fig. As shown in Figure 2, a camber adjustment unit 27 is associated with the body-side bearing 17 of the front upper control arm 7. This unit has a cam track 29 designed as an elongated slot. With the bearing bolt loosened, the bearing pin 25 of the body-side control arm bearing 17 is adjustably guided in the cam track 29. The cam track 29 of the camber adjustment unit 27 is oriented obliquely upwards in the transverse direction y towards the vehicle's interior, with the cam track 29 forming an angle of inclination α with a horizontal plane, which can be between 0° and 45°.

[0026] Furthermore, in the Fig. 2. A track adjustment unit 31 is assigned to the body-side tie rod bearing 16, which has a cam track 33 designed as an elongated hole. In the cam track 33, the bearing bolt 25 of the body-side tie rod bearing 16 is movably guided (with the bearing screw connection loosened). The cam track 33 of the track adjustment unit 31 is oriented obliquely upwards in the transverse direction y towards the outside of the vehicle, with the cam track 33 forming an angle of inclination β with a horizontal plane, which can be between 0° and 30°.

[0027] In the Fig. 3 is in a view according to the Fig. 2 A second embodiment is shown. Its basic structure and function are identical to those of the preceding first embodiment. Therefore, reference is made to the preliminary description. In contrast to the preceding embodiment, in the Fig. 3. The camber adjustment unit 27 is no longer formed on the body-side control arm bearing 17 of the front upper control arm 7, but rather on the wheel carrier-side control arm bearing 19. The alignment of the camber track 29 of the camber adjustment unit 27 is identical to that in the first embodiment of the Fig. 2. The one in the Fig. 3. The indicated implementation of camber adjustment on the wheel carrier side makes particular sense if the longitudinal member 3 of the subframe 1 runs above a drive shaft.

[0028] Similarly, in the Fig. 3. The track adjustment unit 31 is no longer arranged on the body-side tie rod bearing 16, but rather on the wheel carrier-side tie rod bearing 18. The alignment of the cam track 33 of the track adjustment unit 31 is identical to that in the first embodiment of the Fig. 2.

[0029] In the Fig. Figure 4 shows a further embodiment in which the camber adjustment unit 27 with its cam track 29 is formed on the wheel carrier-side control arm bearing 19 of the front upper control arm 7, while the toe adjustment unit 31 is formed on the body-side tie rod bearing 18. The body-side tie rod bearing 18 is located in the Fig. 4 at a rack end of a steering gear 35.

[0030] In the exemplary embodiment of the Fig. 5 is the track adjustment unit 27 - as in the Fig. 4 - formed on the body-side control arm bearing 18 of the front upper control arm 7, while the track adjustment actuating unit 31 is formed on the body-side tie rod bearing 16.

[0031] The one in Fig. The indicated implementation of camber adjustment on the vehicle body side is particularly suitable if the longitudinal member 3 of the subframe 1 runs above a drive shaft. REFERENCE MARK LIST: 1 Subframe 3 longitudinal beams 5 crossbeams 7 upper front handlebar 9 upper rear handlebar 11 lower front handlebar 13 lower rear handlebar 15 tie rod 16 body-side tie rod bearings 17. Body-side handlebar bearing 18 wheel carrier-side tie rod bearing 19 Wheel carrier-side handlebar bearing 21 bike carriers 23 Support spring 25 bearing bolts 27 Camber adjustment unit 29 Scenery Railway 31 Track adjustment unit 33 Scenery Railway 35 Steering gear FR direction of travel HR vehicle wheel QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] US 5 398 411 A

[0008] WO 2016 / 041 706 A1

[0009] EP 2 783 947 B1

[0010] DE 10 2014 226 536 A1

[0010] DE 10 2015 101 438 A1

[0010] DE 10 2014 201 876 A1

[0011] DE 44 37 661 A1

[0011] DE 41 15 110 A1

[0011] EP 1 932 692 A1

[0011]

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