Independent suspension and motor vehicle

Abstract

The present invention relates to an independent wheel suspension (1) for a motor vehicle (2) with a wheel carrier (3) with a wheel axle (4) and with a semi-trailing arm (5). What is essential to the invention is - that the wheel carrier (3) has a first rubber-metal bearing (6), a second rubber-metal bearing (7) and a third rubber-metal bearing (8), via which the wheel carrier (3) is connected to the semi-trailing arm (5), - that the first rubber-metal bearing (6) is arranged in the direction of travel (9) behind the wheel axle (4) of the wheel carrier (3) and the second rubber-metal bearing (7) is arranged in the direction of travel (9) behind and below the wheel axle (4) of the wheel carrier (3), - that the third rubber-metal bearing (8) is arranged in the direction of travel (9) behind and above the wheel axle (4) of the wheel carrier (3), - that the first rubber-metal bearing (6) is softer in the radial direction than the second rubber-metal bearing (7) in the radial direction and the third rubber-metal bearing (8) in the radial direction. This can result in significantly improved driving behavior.

Description

The present invention relates to an independent wheel suspension for a motor vehicle having a wheel carrier with a wheel axle and having a transverse link, according to the preamble of claim 1.From the generic document DE 10 2004 050 624 A1, an inclined steering axle for motor vehicles is known, having a pivotably mounted wheel carrier, the pivot axis of which is inclined in two planes for the purpose of achieving a desired intrinsic steering behavior under load for the wheel to be mounted, and having a track rod connected to the wheel carrier and supported on the subframe of the motor vehicle.DE 10 2009 022 883 A1 discloses an independent wheel suspension for a rear wheel of a passenger vehicle, having a wheel carrier to which a longitudinal link, the free end of which is articulated on the vehicle body via a longitudinal link bearing, which permits a change in track under the action of lateral forces on the wheel, is fixedly connected, and having two links extending in the vehicle transverse direction, which links are articulated on the wheel carrier or longitudinal link and on the vehicle body.DE 10 2015 201 338 A1 discloses an inclined link axle for suspending a wheel on a body of a motor vehicle, having an inclined link which can be connected in an articulated manner to a wheel carrier and having an, in particular active, track rod for pivoting the wheel carrier, which track rod is supported on the inclined link. This is intended to achieve improved driving comfort and reduced noise propagation to the passenger interior.The disadvantage of the independent wheel suspensions known from the prior art is that the used independent wheel suspensions have a driving behavior that is capable of improving.The present invention addresses the problem of specifying an improved or at least one alternative embodiment for an independent wheel suspension of the generic type, which embodiment in particular exhibits an improved driving behavior.This problem is solved according to the invention by the subject matter of independent claim 1. Advantageous embodiments are the subject of the dependent claims.The present invention is based on the general idea of configuring an independent wheel suspension for a motor vehicle for the first time with a wheel carrier separate from an inclined link and of mounting this wheel carrier on the inclined link via three specially configured and arranged rubber-metal bearings, whereby a significantly increased driving comfort and a significantly improved driving dynamics can be achieved. The independent wheel suspension according to the invention for a motor vehicle has the aforementioned wheel carrier with a wheel axle and an oblique link, wherein the wheel carrier according to the invention has a first rubber-metal bearing, a second rubber-metal bearing and a third rubber-metal bearing, via which the wheel carrier is connected to the oblique link. The first rubber-metal bearing is arranged behind the wheel axis of the wheel carrier in the direction of travel, while the second rubber-metal bearing is arranged behind and below the wheel axis of the wheel carrier in the direction of travel. The third rubber-metal bearing is in turn arranged behind and above the wheel axis of the wheel carrier in the direction of travel. All the rubber-metal bearings are thus arranged behind the wheel axle. The first rubber-metal bearing is formed softer in the radial direction than the second rubber-metal bearing in the radial direction and the third rubber-metal bearing in the radial direction. "Softer" in this case is intended to mean that the first rubber-metal bearing has a lower modulus of elasticity than the third rubber-metal bearing and the second rubber-metal bearing. The second and the third bearing are designed to be very stiff radially compared to the first rubber-metal bearing, whereby a good camber stiffness can be ensured. Up to now, the wheel carrier was formed integrally with the wheel axle and the inclined link, so that no relative movement of the wheel carrier with respect to the inclined link was possible, which, however, negatively influenced the driving behavior and also the driving dynamics. By decoupling the wheel carrier from the inclined link by means of the three rubber-metal bearings mentioned and by the selected positions of the individual rubber-metal bearings and by the reduced rigidity of the first rubber-metal bearing in comparison with the second and third rubber-metal bearings, improved driving dynamics can be achieved, in particular understeering behavior during cornering and during braking. Due to the provided positive toe-in change, the motor vehicle can be brought under control more easily even in the event of a break-out by gas removal and steering correction. Due to the increased toe-in at the rear axle of the motor vehicle due to the independent wheel suspension according to the invention, an overall smoother driving behavior of the motor vehicle can be achieved, wherein a rear of the vehicle has more traction during acceleration and during rapid load changes.In an advantageous development of the independent wheel suspension according to the invention, the first rubber-metal bearing is arranged in a closed bearing eye of the inclined link. By virtue of such an arrangement of the first rubber-metal bearing in an associated bearing eye, particularly exact mounting of the first rubber-metal bearing can be achieved, wherein an axis of the first rubber-metal bearing or of the bearing eye can also be oriented deviating from a horizontal and thus has a Z-position. As a result, a slightly oblique placement about a vertical and transverse axis is conceivable, which offers the possibility of selecting an optimum position of the layer with regard to assembly and functionality. In addition, the first rubber-metal bearing can be pressed into the bearing eye and thereby fixed.In a particularly preferred embodiment of the independent wheel suspension according to the invention, the inclined link has an upper arm on which the third rubber-metal bearing is arranged. As a result, it is possible according to the invention to arrange the third rubber-metal bearing behind and above the wheel axis of the wheel carrier, as a result of which the softer first rubber-metal bearing can be used with respect to the second and third rubber-metal bearings-in each case as viewed in the radial direction-to improve the driving dynamics and generally the driving behavior of a motor vehicle equipped with such an individual wheel suspension. The upper arm is formed integrally with the inclined link, for example cast.Expediently, the second rubber-metal bearing is arranged at a lower portion of the inclined link. The first and the second rubber-metal bearing of the wheel carrier are connected to the inclined link in the direction of travel toward the front, thereby making comparatively simple assembly possible. The second rubber-metal bearing is mounted from behind on the lower portion of the inclined link, while the third rubber-metal bearing is mounted from the front on the region at which the free end of the upper arm is located. The closed bearing eye, in which the first rubber-metal bearing is arranged, can be arranged at a branch from the upper arm. The closed bearing eye, i.e. its border, is also formed integrally with the inclined guide arm. Alternatively, the closed bearing eye can also be arranged in the upper arm.In a particularly preferred embodiment of the independent wheel suspension according to the invention, the rubber-metal bearings are oriented with their respective axis substantially in the longitudinal direction of the vehicle. The axial stiffnesses of all three rubber-metal bearings are selected such that this results in a longitudinal flexibility of the wheel carrier with respect to the inclined link, which was not possible in this way in the case of an inclined link and wheel carrier formed in one piece up to now. This additional, soft decoupling brings great advantages in driving comfort, in particular when driving over obstacles and rough roads. The individual rubber-metal bearings can additionally allow a relative movement between the wheel carrier and the inclined link that differs from the respective bearing axis, whereby the driving behavior can be additionally improved.In a further advantageous embodiment, two further rubber-metal bearings are arranged on the inclined link in front of the wheel axle in the direction of travel, which can be connected to a vehicle body of a motor vehicle, wherein a bearing point for supporting a helical spring is also arranged behind the wheel axle in the direction of travel. The two further rubber-metal bearings situated in front of the wheel axle in the direction of travel likewise permit an at least slight relative movement of the inclined link with respect to the vehicle body, while the helical spring permits the vehicle body to be sprung in the vertical direction with respect to the inclined link.The present invention is further based on the general idea of specifying a motor vehicle having an independent wheel suspension described in the preceding paragraphs, as a result of which the advantages described with respect to the independent wheel suspension according to the invention can be transferred to the motor vehicle. Specifically, these advantages lie in a significantly improved driving dynamics and a significantly improved driving comfort, since the independent wheel suspension according to the invention has a multiple longitudinal flexibility compared to the conventional inclined control arm in the case of longitudinal forces occurring in the direction of travel. The five times the longitudinal compliance results from the longitudinal compliance of the three rubber-metal bearings between the wheel carrier and the inclined link and the two further rubber-metal bearings between the inclined link and the vehicle body.In a further advantageous embodiment of the motor vehicle according to the invention, a shock absorber is provided which is connected on the one hand to the inclined link and on the other hand to a vehicle body and engages in a recess on the inclined link. This allows a construction space-optimized and at the same time protected arrangement of the shock absorber.Further features and advantages of the invention are evident from the dependent claims, from the drawings and from the associated description of the figures with reference to the drawings.It is understood that the features mentioned above and those still to be explained below can be used not only in the respectively specified combination, but also in other combinations or alone, without departing from the scope of the invention as defined by the claims. The above-mentioned components of a superordinate unit, such as a device, a device or an arrangement, which are designated separately, can form separate components or components of this unit or can be integral regions or sections of this unit, even if this is illustrated differently in the drawings.Preferred exemplary embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description, wherein the same reference numerals refer to the same or similar or functionally the same components.They show, in each case schematically, FIG. 1 is a top view of an independent wheel suspension according to the invention, FIG. 2 shows a rear view of the independent wheel suspension according to the invention, FIG. 3 is a side view of the independent wheel suspension according to the invention, FIG. 4 is a view as in FIG. 3, but without a disc brake, FIG. 5 shows a top view of a further embodiment of the independent wheel suspension according to the invention with a first rubber-metal bearing displaced in the transverse direction of the vehicle, FIG. 6 shows a rear view of the independent wheel suspension according to the invention corresponding to FIG. 5, FIG. 7 is a side view of the independent wheel suspension according to the invention corresponding to FIG. 5, FIG. 8 shows an illustration as in FIG. 7, but without a disc brake.According to FIGS. 1-8, an independent wheel suspension system 1 according to the invention for a motor vehicle 2 has a wheel carrier 3 with a wheel axle 4 and an inclined link 5. In independent wheel suspensions known hitherto from the prior art, the wheel carrier 3 and the inclined link 5 were configured integrally with one another. This is solved differently in the independent wheel suspension 1 according to the invention, wherein the wheel carrier 3 has a first rubber-metal bearing 6, a second rubber-metal bearing 7 and a third rubber-metal bearing 8, via which the wheel carrier 3 is connected to the inclined link 5.The first rubber-metal bearing 6 is arranged behind the wheel axle 4 of the wheel carrier 3 in the direction of travel 9, while the second rubber-metal bearing 7 is arranged behind and below the wheel axle 4 of the wheel carrier 3 in the direction of travel 9. The third rubber-metal bearing 8 is in turn arranged behind and at the same time above the wheel axle 4 of the wheel carrier 3 in the direction of travel 9. The first rubber-metal bearing 6 is at the same time formed softer in the radial direction, i.e. with lower rigidity, than the third rubber-metal bearing 8 and the second rubber-metal bearing 7.The independent wheel suspensions 1 shown on the one hand in FIGS. 1 to 4 and on the other hand in FIGS. 5 to 8 differ in the arrangement of a brake caliper 13 of a disc brake 12 which, in the case of the independent wheel suspensions 1 according to FIGS. 1 to 4, is arranged in front of the wheel axle 4 in the direction of travel 9 and, in the case of the independent wheel suspensions 1 according to FIGS. 5 to 8, is arranged behind the wheel axle 4 in the direction of travel 9.The elastic rubber-metal bearings 6, 7, 8 can have two concentric sleeves or a sleeve and a bolt, in which an elastomer body is non-detachably integrated at least in regions.This allows a considerably improved driving dynamics and a positive toe-in change to be achieved, which leads to an under-steering behavior during cornering and during braking. The increased toe-in overall allows achieving a smoother driving behavior, wherein a rear of the motor vehicle 2 has more traction during acceleration and also during rapid load changes. The independent wheel suspension 1 is arranged on the rear wheels of the motor vehicle 2.The first rubber-metal bearing 6, as can be seen from FIGS. 2 and 6, is arranged, in particular pressed, in a closed bearing eye 10 of the inclined link 5. This allows the first bearing 6 to be radially fixed in the bearing eye 10. As can be clearly seen in FIG. 2 in particular, the bearing eye 10 is arranged on a branch 23 of an upper arm 11 of the inclined link 5, wherein the second rubber-metal bearing 7 is connected at the same time to a lower section 14. The entire inclined link 5 is preferably formed in one piece. As can be seen in particular from FIG. 6, there is no branch 23, so that the bearing eye 10 is arranged directly in the upper arm 11 of the inclined link 5. The first rubber-metal bearing 6 is thus displaced in the vehicle transverse direction. On the upper arm 11, the third rubber-metal bearing 8 is also disposed.The rubber-metal bearings 6, 7 and 8 are preferably oriented parallel with respect to their axes, it also being conceivable for the first rubber-metal bearing 6 to have a Z-direction inclination. In addition, the individual rubber-metal bearings 6, 7 and 8 are oriented with their respective axis substantially in the vehicle longitudinal direction. An axial direction usually runs parallel to an axial direction of an associated bearing eye 10 or of a connection point at which the respective rubber-metal bearing 6, 7, 8 is connected to the inclined link 5.If the inclined link 5 is viewed further, it can be seen that two further rubber-metal bearings 15, 16 are arranged in front of the wheel axle 4 and also in front of the first rubber-metal bearing 6 in the direction of travel 9, via which the inclined link 5 can be connected to a vehicle body, which is not shown in more detail. The axes of the further rubber-metal bearings 15, 16 are oriented obliquely to the axes of the rubber-metal bearings 6, 7 and 8.Behind the wheel axle 4 in the direction of travel 9 is a bearing point 17 for supporting a helical spring 18 (compare FIGS. 2 to 4 and 6 to 8), wherein the bearing point 17 is likewise formed integrally with the inclined link 5. In addition, a shock absorber 19 is provided which is connected on the one hand to the inclined link 5 and on the other hand to a body of the motor vehicle 2, which body is not designated in any more detail. The shock absorber 19 engages in a recess 24 on the inclined link 5, whereby an installation space-optimized and at the same time protected arrangement of the shock absorber 19 is made possible.Furthermore, a connection point 20 for connecting a stabilizer 21 is arranged on the inclined link 5, wherein the stabilizer 21 is connected to the connection point 20 of the inclined link 5 via a pendulum support 22 and as a result cannot transmit any moments to the inclined link 5.All in all, a significantly improved driving behavior can be achieved with the independent wheel suspension 1 according to the invention, wherein the connection points for connecting the independent wheel suspension 1 according to the invention to the motor vehicle 2 or its vehicle body are unchanged from previous independent wheel suspensions from the prior art, in which the wheel carrier 3 and the inclined link 5 were formed in one piece. In particular, due to the multiple longitudinal flexibility in the independent wheel suspension 1 according to the invention in the case of longitudinal forces occurring in the direction of travel 9, the driving behavior can be significantly improved. The multiple longitudinal compliance results from the longitudinal compliance of the three rubber-metal bearings 6, 7, 8 between the wheel carrier 3 and the inclined link 5 and the two further rubber-metal bearings 15, 16 between the inclined link 5 and the vehicle body.

Claims

Independent wheel suspension (1) for a motor vehicle (2), - with a wheel carrier (3) with a wheel axle (4), - with an inclined link (5), characterized - in that the wheel carrier (3) has a first rubber-metal bearing (6), a second rubber-metal bearing (7) and a third rubber-metal bearing (8), via which the wheel carrier (3) is connected to the inclined link (5), - in that the first rubber-metal bearing (6) is arranged behind the wheel axle (4) of the wheel carrier (3) in the direction of travel (9) and the second rubber-metal bearing (7) is arranged behind and below the wheel axle (4) of the wheel carrier (3) in the direction of travel (9), the third rubber-metal bearing (8) is arranged behind and above the wheel axle (4) of the wheel carrier (3) in the direction of travel (9), the first rubber-metal bearing (6) is designed to be softer in the radial direction than the second rubber-metal bearing (7) in the radial direction and the third rubber-metal bearing (8) in the radial direction.Independent wheel suspension (1) according to Claim 1, characterized in that the first rubber-metal bearing (6) is arranged in a closed bearing eye (10) of the inclined link (5).Independent wheel suspension (1) according to Claim 1 or 2, characterized in that the inclined link (5) has an upper arm (11), in which the third rubber-metal bearing (8) is arranged.Independent wheel suspension (1) according to Claim 2 and Claim 3, characterized in that the bearing eye (10) is arranged at a branch (23) of the upper arm (11) or in the same.Independent wheel suspension (1) according to one of the preceding claims, characterized in that the second rubber-metal bearing (7) is arranged on a lower section (14) of the inclined link (5).Independent wheel suspension (1) according to one of the preceding claims, characterized in that the rubber-metal bearings (6, 7, 8) are oriented with their respective axis substantially in the vehicle longitudinal direction.Independent wheel suspension (1) according to one of the preceding claims, characterized in that two further rubber-metal bearings (15, 16) are arranged on the inclined link (5) in front of the wheel axle (4) in the direction of travel (9), which can be connected to a vehicle body.Independent wheel suspension (1) according to one of the preceding claims, characterized - in that a bearing point (17) for supporting a helical spring (18) is arranged on the inclined link (5) behind the wheel axle (4) in the direction of travel (9), and / or - in that a disc brake (12) is provided, the brake caliper (13) of which is arranged in front of or behind the wheel axle (4).Motor vehicle (2) having an independent wheel suspension (1) according to one of the preceding claims.Motor vehicle (2) according to Claim 9, characterized in that a shock absorber (19) is provided, which is connected on the one hand to the inclined link (5) and on the other hand to a vehicle body.

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