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 four rubber-metal bearings (6, 7, 8, 12) via which the wheel carrier (3) is connected to the semi-trailing arm (5), - that the first rubber-metal bearing (6) is arranged in front of the wheel axle (4) 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), - that the third rubber-metal bearing (8) and the fourth rubber-metal bearing (12) are arranged behind the wheel axle (4) in the direction of travel (9), - that the first rubber-metal bearing (6) and the fourth rubber-metal bearing (12) are 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.DE 23 11 480 A discloses a wheel suspension for non-steered rear wheels of motor vehicles, having wheel guide members held on the body or on the frame and a wheel carrier articulated thereto via elastic elements, wherein the guided wheel is adjustable in the direction of toe-in or toe-out under the action of forces acting thereon about a wheel steering pole provided behind the vertical transverse plane of the wheel in plan view.FR 2 621 277 A1 discloses a generic wheel suspension having four bearing points.EP 0 974 475 A1 discloses an independent wheel suspension of the transverse or torsion beam type with a wheel-guiding transverse or torsion beam mounted at at least two points on the vehicle body, which has a wheel carrier pivotable approximately about a vertical axis, wherein the pivot axis of the wheel carrier lies behind the wheel axis with respect to the direction of travel, while the wheel carrier is elastically supported on the transverse or torsion beam in front of the wheel axis in the transverse direction of the vehicle.DE 103 21 879 A1 discloses an independent wheel suspension with a rear wheel support mounted on an axle component that can be pivoted about an at least approximately horizontal pivot axis, which support has at least one wheel-guiding link that is predominantly aligned in the horizontal direction, by means of which it is supported in an articulated manner on the pivotable axle component.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 claims 1 and 9. 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 four 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 inclined link, wherein the wheel carrier according to the invention has a first rubber-metal bearing, a second rubber-metal bearing, a third rubber-metal bearing and a fourth rubber-metal bearing, via which the wheel carrier is connected to the inclined link. The first rubber-metal bearing is arranged in front of 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, while the fourth rubber-metal bearing is arranged behind the wheel axis of the wheel carrier in the direction of travel. The first rubber-metal bearing and the fourth rubber-metal bearing are thereby 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" is intended in this case to mean that the first and fourth rubber-metal bearings have 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 and fourth rubber-metal bearings, 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 four rubber-metal bearings mentioned and by the selected positions of the individual rubber-metal bearings and by the reduced rigidity of the first and fourth rubber-metal bearings 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 changesIn 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, whereby the vehicle dynamics and generally the driving behavior of a motor vehicle equipped with such an independent wheel suspension can be improved with the softer first and fourth rubber-metal bearings in relation to the second and third rubber-metal bearings, in each case in the radial direction, that is to say transversely to the axis of the respective rubber-metal bearing. 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. A connection of the first, the second and the fourth rubber-metal bearing of the wheel carrier to the inclined link is effected in the direction of travel toward the front, whereby a comparatively simple assembly is made possible. The third rubber-metal bearing is placed on the upper arm from the front or is arranged in a bearing eye thereof. The second rubber-metal bearing is thus placed from behind on the lower portion of the inclined link, while the third rubber-metal bearing is placed from the front on the region at which the free end of the upper arm is located. The closed bearing eye, in which the fourth rubber-metal bearing is arranged, is 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, i.e. displaced in the transverse direction of the vehicle.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 four 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 six times longitudinal compliance results from the longitudinal compliance of the four 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 important 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.According to FIGS. 1-3, 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 and a fourth rubber-metal bearing 12, 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 fourth rubber-metal bearing 12 is likewise arranged behind the wheel axle 4 as viewed in the direction of travel 9. The fourth rubber-metal bearing 12 can then be arranged approximately at the height of the first rubber-metal bearing 6, in particular on a line with the first rubber-metal bearing 6 and the wheel axle 4.On the independent wheel suspensions 1 shown in FIGS. 1 to 3, a brake, not shown, in particular a drum brake or a disc brake, can also be arranged.The elastic rubber-metal bearings 6, 7, 8, 12 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. 1 and 3, 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, the fourth rubber-metal bearing 12 is also arranged in a bearing eye 10', wherein the bearing eye 10' is arranged on a branch 13 of an upper arm 11 of the inclined link 5 and 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.The tilt arm 5 further has the above-mentioned upper arm 11 on which the third rubber-metal bearing 8 is disposed.The rubber-metal bearings 6, 7, 8 and 12 are preferably oriented parallel with respect to their axes, wherein it is also conceivable that the first rubber-metal bearing 6 has a Z-direction inclination. In addition, the individual rubber-metal bearings 6, 7, 8 and 12 are oriented with their respective axis substantially in the vehicle longitudinal direction.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, 8 and 12.Behind the wheel axle 4 in the direction of travel 9, a bearing point 17 is arranged for supporting a helical spring 18, the bearing point 17 likewise being 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 23 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 four rubber-metal bearings 6, 7, 8, 12 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), - wherein the wheel carrier (3) has a first rubber-metal bearing (6), a second rubber-metal bearing (7), a third rubber-metal bearing (8) and a fourth rubber-metal bearing (12), via which the wheel carrier (3) is connected to the inclined link (5), characterized - in that the first rubber-metal bearing (6) is arranged in front of 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 axis (4) of the wheel carrier (3) in the direction of travel (9), the fourth rubber-metal bearing (12) is arranged behind the wheel axis (4) of the wheel carrier (3) in the direction of travel (9), the first rubber-metal bearing (6) and the fourth rubber-metal bearing (12) are 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), on which the third rubber-metal bearing (8) is arranged.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 Claim 3, characterized in that the fourth rubber-metal bearing is arranged in a bearing eye (10') at a branch (13) of the upper arm (11).Independent wheel suspension (1) according to one of the preceding claims, characterized in that the rubber-metal bearings (6, 7, 8, 12) 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).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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