Wheel suspension for one vehicle axle

Abstract

Wheel suspension for a vehicle axle (HA) of a two-track vehicle, with a wheel carrier (1) supporting a vehicle wheel (2), which can be articulated to a vehicle body via a multi-link system (3), which multi-link system (3) has a trapezoidal link (L1) designed as a four-point link with two body-side connection points (21, 23) and with two wheel carrier-side connection points (25, 27), characterized in that both wheel carrier-side trapezoidal link connection points (25, 27) are designed with a greater elastic longitudinal compliance, i.e. softer, than the body-side trapezoidal link connection points (21, 23), and that when a longitudinal force is applied to the vehicle wheel (2), the wheel carrier (1) can be displaced with respect to the trapezoidal link (L1) by a longitudinal path (Δx) in the longitudinal direction (x) of the vehicle.

Description

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

[0002] Such a wheel suspension comprises a wheel carrier supporting a vehicle wheel, which is connected to a subframe or axle carrier of the vehicle via a multi-link assembly. The subframe, in turn, is connected to the vehicle body (e.g., the body side members) via subframe bearings.

[0003] When the vehicle drives over an edge or accelerates or brakes, a longitudinal force acts on the vehicle wheel. With a view to longitudinal spring comfort, the subframe mounts, via which the subframe is connected to the body, are designed in the prior art with increased elastic longitudinal compliance in the vehicle's longitudinal direction in order to absorb the longitudinal force acting on the vehicle wheel. In the case of a trapezoidal link vehicle axle, this also results in a twisting of the trapezoidal link and / or a longitudinal displacement of the trapezoidal link by a longitudinal path in the vehicle's longitudinal direction. In the above case, the trapezoidal link's longitudinal travel is limited in particular by stops on the trapezoidal link mounts located inside the vehicle.

[0004] If the above-mentioned vehicle axle, designed for longitudinal suspension comfort, is electrically operated, the following situation arises: An electric motor can be mounted either on the subframe or close to the wheel on the trapezoidal link of the wheel suspension and be connected to the vehicle wheel via a drive shaft. In this case, a longitudinal force acting on the vehicle wheel will result in undesirable vibrations of the electric motor due to the longitudinal displacement of the subframe and / or the trapezoidal link.

[0005] DE 10 2011 055 704 A1 discloses a multi-link rear axle for a motor vehicle with a trapezoidal link. DE 694 12 909 T2 also discloses a wheel suspension with a trapezoidal link.

[0006] DE 10 2005 030 810 A1 discloses a generic wheel suspension for the rear wheels of motor vehicles. DE 10 2005 049 947 A1 discloses a wheel suspension for the driven rear wheels of a motor vehicle. DE 10 2014 225 884 A1 discloses a connecting element between a transverse leaf spring and a wheel carrier of a motor vehicle wheel suspension. US 2009 / 0 184 484 A1 discloses another wheel suspension.

[0007] The object of the invention is to provide a wheel suspension with particularly high longitudinal comfort. Furthermore, the wheel suspension should prevent unwanted vibrations caused by the mass of the electric motor in an electrically driven vehicle axle.

[0008] The object is solved by the features of claim 1. Preferred developments of the invention are disclosed in the subclaims.

[0009] The invention is based on a wheel suspension whose wheel carrier is articulated to the vehicle body via a multi-link assembly. The multi-link assembly has a trapezoidal link designed as a four-point link, which has two connection points on the body side and two connection points on the wheel carrier side. According to the characterizing part, the wheel carrier-side connection points are designed with greater elastic longitudinal compliance, i.e., are softer, than the body-side connection points. When a longitudinal force acts on the vehicle wheel, the wheel carrier is therefore displaced by a longitudinal path in the vehicle's longitudinal direction with respect to the trapezoidal link (which largely does not shift longitudinally). Due to the now greater longitudinal compliance on the wheel carrier side, the subframe bearings can be made stiffer.The following advantage arises, particularly when the vehicle axle is combined with an electric motor: The electric motor can be mounted on the subframe or, if mounted close to the wheel, on the trapezoidal link. According to the invention, when longitudinal forces act on the vehicle wheel, there is no or only minimal longitudinal movement of the subframe or the trapezoidal link due to the now stiffer subframe bearings and / or the trapezoidal link bearings on the body. Accordingly, the electric motor mounted on the subframe or the trapezoidal link is also not subject to any longitudinal movement, thus eliminating or significantly reducing unwanted vibrations during driving.

[0010] In one technical implementation, the multi-link assembly is connected to a subframe via body-side connection points. The subframe, in turn, is connected to the vehicle body (e.g., body side members) via subframe mounts. The subframe or the trapezoidal link can support an electric motor, which is drivingly connected to the vehicle wheel via a drive shaft. According to the invention, the subframe mounts and the body-side connection points of the multi-link assembly are designed in the vehicle's longitudinal direction compared to the wheel-carrier-side trapezoidal link connection points in such a way that the majority of the longitudinal compliance results from the wheel-carrier-side connection.

[0011] In addition to the trapezoidal link, the multi-link assembly can have exactly three additional check arms. These can be provided, in particular, as two-point control arms, each with a body-side connection point and a wheel-carrier-side connection point. The three additional check arms can preferably be implemented as wishbones that extend in line with the vehicle's transverse direction. All body-side and wheel-carrier-side connection points of the multi-link assembly can be implemented as pivot bearings with a pivot axis aligned with the vehicle's longitudinal direction.

[0012] The three additional check valves can dictate the wheel carrier movement when a longitudinal force acts on the vehicle wheel. This primarily involves a longitudinal displacement of the wheel carrier, superimposed on a slight toe-in or toe-out rotation of the wheel carrier.

[0013] In a specific design variant, the trapezoidal control arm can be arranged together with a lower wheel control arm on the vehicle's lower control arm in a lower control arm plane. In the lower control arm plane, the lower wheel control arm can be positioned below the trapezoidal control arm by a free vertical offset. The wheel carrier-side connection point of the lower wheel control arm can thus be positioned below the wheel carrier-side trapezoidal control arm connection points by a vertical offset.

[0014] A front upper check rail and a rear upper check rail can be arranged in an upper control rail level. The wheel carrier-side connection point of the front upper check rail and the front trapezoidal control rail connection points can be arranged in front of a vehicle wheel pivot axis in the direction of travel. In contrast, the wheel carrier-side connection points of the lower check rail and the rear upper check rail, as well as the rear trapezoidal control rail connection points, can be arranged behind the vehicle wheel pivot axis.

[0015] In a further development of the invention, the wheel carrier-side connection point of the front, upper check arm can be arranged in front of the wheel carrier-side, front trapezoidal control arm connection point by a longitudinal offset. Alternatively and / or additionally, the wheel carrier-side connection point of the front, upper check arm can be arranged vertically offset above the wheel carrier-side, front trapezoidal control arm connection point.

[0016] The wheel carrier-side connection point of the rear upper check arm can be positioned vertically above the rear wheel carrier-side trapezoidal link connection point. Alternatively and / or additionally, the wheel carrier-side connection point of the rear upper check arm can be positioned longitudinally in front of the rear wheel carrier-side trapezoidal link connection point.

[0017] In a first embodiment, the wheel-carrier-side trapezoidal link connection points can be implemented as rubber-metal sleeve bearings. To limit the wheel-carrier's longitudinal travel (when longitudinal forces act on the vehicle wheel), axially acting longitudinal stops can be provided in the respective rubber-metal sleeve bearing. Each of the rubber-metal sleeve bearings can have an inner bearing sleeve through which a bearing pin defining the pivot axis is guided, an outer bearing sleeve connected to the trapezoidal bearing, and an elastomer body. The elastomer body can connect the inner and outer bearing sleeves. The bearing pin can be mounted in opposing wheel-carrier bracket wings.

[0018] In a second design variant, the wheel-carrier-side trapezoidal link connection points can be implemented not as rubber-metal sleeve bearings, but rather with coupling rods, via which the trapezoidal link is suspended from the wheel carrier. Each of the coupling rods can be pivoted at a lower pivot point on the trapezoidal link and at an upper pivot point on the wheel carrier. The pivot points can be implemented as pivot bearings with pivot axes aligned with the vehicle's transverse direction. To limit the wheel carrier's longitudinal travel, a spring-damper element can be interposed between the trapezoidal link and the wheel carrier.

[0019] An embodiment of the invention is described below with reference to the attached figures.

[0020] They show: Fig. 1 to 4 show different views of a wheel suspension for a vehicle axle of a two-track vehicle according to a first embodiment; and Fig. 5 and Fig. 6 further views of a second embodiment of the wheel suspension.

[0021] In the Fig. Figure 1 shows the left wheel suspension of an electrically operated rear axle HA of a two-track vehicle. The right-side wheel suspension, not shown in the figures, is mirrored with respect to a vehicle's longitudinal center plane. Fig. 1, the wheel suspension has a wheel carrier 1 carrying a vehicle wheel 2, which is connected via a multi-link assembly 3 (only in Fig. 2) is hinged to a body-side subframe 5. The subframe 5 has in the Fig. 1 has two lateral subframe longitudinal members 7, of which in the Fig. 1 or Fig. 2 only one is shown. The two subframe longitudinal members 7 are connected to each other via front and rear subframe cross members 9. The subframe 5 carries in the Fig. 2 an electric machine 11, which is only roughly schematically indicated by a dashed line. The electric machine 11 is connected to the vehicle wheel 2 via a drive shaft 13. The subframe longitudinal member 7 is in the Fig. 1 or Fig. 2 connected to the indicated front and rear subframe bearings 15 on the vehicle body.

[0022] As can be seen from the figures, the multi-link assembly 3 has a trapezoidal link L1 designed as a four-point link. This is connected to a vertical offset z3 ( Fig. 4) The lower control arm L3 is arranged below the trapezoidal control arm L1 in a lower control arm plane. A front, upper control arm L2 and a rear, upper control arm L4 are arranged in an upper control arm plane of the wheel suspension. The trapezoidal control arm L1 has a flat, plate-shaped base body on which a suspension spring 17 and a telescopic shock absorber 19 are supported. The trapezoidal control arm L1 is implemented as a four-point control arm, which is articulated at two body-side connection points 21, 23 on the subframe 5 and at two wheel carrier-side connection points 25, 27 on the wheel carrier 1. The other control arms L2, L3 and L4 are arranged in the Fig. 1 is designed as a two-point link, each with a body-side connection point and a wheel-carrier-side connection point 29, 31, 33. The three wheel check arms L2, L3, L4 are wishbones that extend in line with the vehicle's transverse direction y. All body- and wheel-carrier-side connection points of the multi-link assembly 3 are shown in the figures as pivot bearings with a pivot axis S aligned with the vehicle's longitudinal direction x. x realized.

[0023] The control arm arrangement is described in detail below: Accordingly, the wheel carrier-side connection point 29 of the front upper wheel control arm L2 and the two vehicle-front trapezoidal control arm connection points 21, 25 are in the direction of travel FR in front of a vehicle wheel rotation axis D ( Fig. 3). The wheel carrier-side connection point 31 of the lower check rail L3 and the wheel carrier-side connection point 33 of the rear, upper check rail L4 are arranged in the Fig. 2 or 3 arranged behind the vehicle wheel rotation axis D.

[0024] In the Fig. 2, the wheel carrier-side connection point 29 of the front, upper wheel guide L2 is offset by a longitudinal offset x2 ( Fig. 3) is arranged in front of the wheel carrier-side, front trapezoidal link connection point 25. In addition, the wheel carrier-side connection point 29 of the front, upper wheel guide L2 is offset by a vertical offset z2 ( Fig. 3) positioned above the wheel carrier-side, front trapezoidal link connection point 25.

[0025] The wheel carrier-side connection point 33 of the rear, upper wheel control arm L4 is positioned by a vertical offset z4 above the rear wheel carrier-side trapezoidal control arm connection point 27. Furthermore, the wheel carrier-side connection point 33 is positioned by a longitudinal offset in front of the rear wheel carrier-side trapezoidal control arm connection point 27.

[0026] The front body-side and wheel-carrier-side trapezoidal link connection points 21, 25 are positioned next to each other approximately in alignment with the vehicle's transverse direction y. Similarly, the rear body-side and wheel-carrier-side trapezoidal link connection points 23, 27 are positioned transversely to each other.

[0027] In the first embodiment of the Fig. 1 to 4, the wheel carrier-side trapezoidal link connection points 25, 27 are implemented as rubber-metal sleeve bearings. Each of the rubber-metal sleeve bearings has Fig. 4 has an inner bearing sleeve 35 through which a bearing pin 37 defining the pivot axis S is guided. The bearing pin 37 is provided with wheel carrier bracket wings 39 ( Fig. 2). The rubber-metal sleeve bearing is pressed into an eyelet 41 on the outside of the trapezoidal link.

[0028] The core of the invention relates to the fact that the wheel carrier-side trapezoidal link connection points 25, 27, which are implemented as rubber-metal sleeve bearings, are designed with a greater elastic longitudinal flexibility, i.e. softer, than the body-side trapezoidal link connection points 21, 23 and the subframe bearings 15. When a longitudinal force acts on the vehicle wheel 2 during driving, the wheel carrier 1 is therefore moved with respect to the trapezoidal link L1 by a longitudinal path Δx ( Fig. 2) in the vehicle's longitudinal direction x. The trapezoidal control arm L1 and the subframe 5, however, are not displaced or are displaced only slightly in the vehicle's longitudinal direction x. To limit the wheel carrier's longitudinal travel Δx, the rubber-metal sleeve bearings have axially acting longitudinal stops.

[0029] The longitudinal displacement over the longitudinal path Δx of wheel carrier 1 is determined by the three check valves L2, L3, and L4. A slight toe-in or toe-out rotation can be superimposed on the longitudinal displacement of wheel carrier 1.

[0030] In the Fig. 5 or Fig. 6 shows a wheel suspension according to a second embodiment. The basic structure and the functioning of the Fig. 5 or Fig. The wheel suspension shown in Figure 6 is essentially identical to the structure / function of the first embodiment. In contrast to the Fig. 1, in the second embodiment, the wheel carrier-side trapezoidal link connection points 25, 27 are not realized as rubber-metal sleeve bearings, but rather with a coupling rod 47, 49 each.

[0031] In the Fig. 5 or Fig. 6, the two coupling rods 47, 49 are aligned approximately vertically. Each of the coupling rods 47, 49 is pivoted at a lower pivot point 51 on the trapezoidal link L1 and pivoted at an upper pivot point 53 on the wheel carrier 1. The upper and lower pivot points 51, 53 are designed as pivot bearings with pivot axes S aligned in alignment with the vehicle's transverse direction y. y To limit the wheel carrier's longitudinal travel Δx, a spring-damper element 57 is arranged between a front support arm 55 of the trapezoidal link L1 and the wheel carrier 1.

[0032] In the Fig. 6, the electric motor 11 is not supported on the subframe 5, but is supported in a wheel-near bearing directly on the trapezoidal control arm L1, namely between the front upper control arm L2 and the rear upper control arm L4. LIST OF REFERENCE SYMBOLS: 1 wheel carrier 2 vehicle wheel 3 Multi-link association 5 subframes 7 subframe longitudinal members 9 subframe cross members 11 Electric machine 13 Drive shaft 15 subframe bearings 17 Suspension spring 19 shock absorbers 21 front body-side trapezoidal link connection point 23 rear body-side trapezoidal link connection point 25 front wheel carrier-side trapezoidal link connection point 27 rear wheel carrier-side trapezoidal link connection point 29, 31, 33 wheel carrier connection points of the control arms L2, L3, L4 35 Bearing inner sleeve 37 bearing bolts 39 Console wing of the wheel carrier 41 Bearing mount in the trapezoidal link 45 elastomer bodies 47, 49 coupling rod 51 lower pivot point 53 upper pivot point S x , S y Swivel axes 55 trapezoidal link support arm 57 Spring-damper element L1 trapezoidal handlebar L2, L3, L4 wishbones HA vehicle axle D Vehicle wheel rotation axis FR direction of travel Δx longitudinal path S x , S y Swivel axes

Claims

[1] Wheel suspension for a vehicle axle (HA) of a two-track vehicle, with a wheel carrier (1) carrying a vehicle wheel (2) which can be linked to a vehicle body via a multi-link assembly (3), which multi-link assembly (3) has a trapezoidal link (L1) designed as a four-point link with two body-side connection points (21, 23) and with two wheel carrier-side connection points (25, 27), characterized by that both wheel carrier-side trapezoidal link connection points (25, 27) are designed with a greater elastic longitudinal flexibility, i.e. softer, than the body-side trapezoidal link connection points (21, 23), and that when a longitudinal force acts on the vehicle wheel (2), the wheel carrier (1) can be displaced with respect to the trapezoidal link (L1) by a longitudinal path (Δx) in the vehicle's longitudinal direction (x). [2] Wheel suspension according to claim 1, characterized bythat the multi-link assembly (3) is articulated to a subframe (5) via the body-side connection points (21, 23), and that the subframe (5) is connected to the vehicle body via subframe bearings (15), and that the subframe (5) or the trapezoidal link (L1) carries an electric machine (11) which is drivingly connected to the vehicle wheel (2) via a drive shaft (13). [3] Wheel suspension according to claim 2, characterized by that the subframe bearings (15) and the body-side connection points (21, 23) of the trapezoidal control arm (L1) in the vehicle longitudinal direction (x) are designed with a reduced elastic longitudinal flexibility, i.e. harder, than the wheel carrier-side trapezoidal control arm connection points (25, 27). [4] Wheel suspension according to claim 1, 2 or 3, characterized bythat the multi-link assembly (3) has, in addition to the trapezoidal link (L1), exactly three further wheel check arms (L2, L3, L4), which are provided as two-point links, each with a body-side connection point and a wheel carrier-side connection point (29, 31, 33), and that the three wheel check arms (L2, L3, L4) are implemented as wishbones which extend in alignment with the vehicle transverse direction (y), and / or that the body-side and wheel carrier-side connection points of the multi-link assembly (3) are designed as pivot bearings with a pivot axis (S x ) are realized. [5] Wheel suspension according to claim 4, characterized bythat the trapezoidal control arm (L1) is arranged together with a vehicle's lower wheel control arm (L3) in a lower control arm plane, in which the vehicle's lower wheel control arm (L3) is positioned by a vertical offset (z3) below the trapezoidal control arm (L1), and that a front, upper wheel control arm (L2) and a rear upper wheel control arm (L4) are arranged in an upper control arm plane, and / or that the wheel carrier-side connection point (29) of the front upper wheel control arm (L2) and the front trapezoidal control arm connection point (25) are arranged in front of a vehicle wheel rotation axis (D) in the direction of travel (FR), and that the wheel carrier-side connection points (31, 33) of the lower wheel control arm (L3) and of the rear upper wheel control arm (L4) and the vehicle-rear trapezoidal control arm connection point (27) are arranged behind the vehicle wheel rotation axis (D) are. [6] Wheel suspension according to claim 5, characterized bythat the wheel carrier-side connection point (29) of the front, upper wheel control arm (L2) is arranged by a longitudinal offset (x2) in front of and / or by a vertical offset (z2) above the wheel carrier-side, front trapezoidal control arm connection point (25), and / or that the wheel carrier-side connection point (33) of the rear, upper wheel control arm (L4) is arranged by a vertical offset (z4) above and / or by a longitudinal offset in front of the rear wheel carrier-side trapezoidal control arm connection point (27). [7] Wheel suspension according to one of claims 4 to 6, characterized bythat the wheel carrier-side trapezoidal control arm connection points (25, 27) are realized as rubber-metal sleeve bearings, and that axially acting longitudinal stops are provided in the rubber-metal sleeve bearings to limit the wheel carrier longitudinal travel (Δx), and / or that each of the rubber-metal sleeve bearings is pressed into the bearing receptacles (41) in the trapezoidal control arm (L1) on the wheel carrier side and has an inner bearing sleeve (35) through which a pivot axis (S x ) defining bearing pin (37) and has an elastomer body (45), wherein the bearing pin (37) is mounted in console wings (39) of the wheel carrier (1). [8] Wheel suspension according to one of claims 1 to 3, characterized bythat each of the wheel carrier-side trapezoidal link connection points (25, 27) is realized with a coupling rod (47, 49), and that the coupling rod (47, 49) is articulated at a lower articulation point (51) on the trapezoidal link (L1) and is articulated at an upper articulation point (53) on the wheel carrier (1), and that the articulation points (51, 53) are pivot bearings with pivot axes (S y ), and that a spring-damper element (57) acts between the trapezoidal link (L1) and the wheel carrier (1) to limit the wheel carrier longitudinal travel (Δx). [9] Wheel suspension according to claim 2, characterized by that the electric machine (11) is supported on the trapezoidal link (L1), between a front upper link (L2) and a rear upper link (L4).

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