Motor-vehicle provided with a multi-link wheel suspension system

Abstract

A motor-vehicle comprising a multi-link wheel suspension system (1), including: - a suspension support frame (2), a wheel support (4) for each wheel of the suspension system, a group of oscillating elements (5) comprising at least one lower oscillating element (6) and at least one upper oscillating element (11, 12), having respective first ends (7, 11', 12') pivotally connected to the wheel support (4), wherein said at least one lower oscillating element (6) comprises a second end (9) connected to said support frame (2), and at least one connecting oscillating lever (10) which connects said at least one upper element (11, 12) to said at least one lower element (6).

Description

[0001] “Motor-vehicle provided with a multi-link wheel suspension system”

[0002] ****

[0003] TEXT OF THE DESCRIPTION

[0004] Field of the invention

[0005] The present invention relates to motor-vehicles of the type comprising a multi-link wheel suspension system including:

[0006] - a suspension support frame, mounted on the body of the motorvehicle, or forming part of said body,

[0007] - a wheel support for each wheel of the suspension system, connected to the support frame by means of a group of oscillating elements,

[0008] - wherein said group of oscillating elements comprises at least one lower oscillating element and at least one upper oscillating element, having respective first ends pivotally connected to the wheel support in correspondence with respective lower and upper connection portions of the wheel support.

[0009] Prior art

[0010] Suspension prototypes of the type indicated above are mainly used for premium type vehicles and for high performance sports vehicles. Such suspension prototypes achieve optimal management of driving performance, comfort and control compared to simpler suspensions.

[0011] Typically, the group of oscillating elements consists of one or more lower oscillating elements (for example a wishbone or two articulated connecting rods) and upper oscillating elements (for example two articulated rods). All oscillating elements (upper and lower) have respective portions of opposite ends connected to the wheel support and the support frame. The latter, depending on the vehicle model, can be arranged to accommodate a differential unit or an electric motor.

[0012] Suspensions as described above, in the final configuration installed on the vehicle, occupy a significant volume since space must be provided for the connection to the support frame of all oscillating elements. Consequently, the side members of the vehicle floor, in their part proximal to the support frame, must have an adequate profile, usually curvilinear rather than straight, to allow the connection of the upper oscillating elements to the support frame. These features of the side members are disadvantageous from the point of view of crash performance, as side members with a curvilinear section have overall energy absorption properties that are significantly less effective than corresponding side members with a totally straight profile.

[0013] Object of the invention

[0014] It is therefore an object of the present invention to provide a multi-link suspension system for motor-vehicles, which satisfies the performance requirements of vehicle dynamics for high-performance vehicles, while having a limited overall size that does not require the modification of other parts of the vehicle, such as the shape of the side members.

[0015] Summary of the invention

[0016] In order to achieve said purpose, the invention has as its object a motor-vehicle comprising a multi-link wheel suspension system, including:

[0017] - a suspension support frame,

[0018] - a wheel support for each wheel of the vehicle axle on which said suspension system is provided, wherein said wheel support is connected to the support frame by means of a group of oscillating elements,

[0019] - wherein said group of oscillating elements comprises at least one lower oscillating element and at least one upper oscillating element, having respective first ends pivotally connected to the wheel support in correspondence with respective lower and upper connection portions,

[0020] - wherein said at least one lower oscillating element comprises a second end connected to said support frame,

[0021] - characterized in that said at least one upper oscillating element is not directly connected to said support frame, and in that the group of oscillating elements includes at least one connecting oscillating lever which connects said at least one upper element to said at least one lower element.

[0022] In a preferred embodiment, said at least one upper oscillating element comprises a pair of upper articulated rods comprising a first upper rod and a second upper rod, and said at least one oscillating lever comprises a rocker lever adapted to connect respective second ends of the two rods to the lower oscillating element (6). Brief description of the figures

[0023] Further features and advantages of the invention will be apparent from the following description with reference to the attached drawings, provided purely by way of non-limiting example, in which:

[0024] - figure 1 is a schematic perspective view of a motor-vehicle suspension system, according to an embodiment of the present invention, and

[0025] - figures 2, 3 are further enlarged scale perspective views illustrating the suspension of Figure 1 .

[0026] Detailed description of the invention

[0027] In the following description, various specific details are illustrated aimed at a thorough understanding of examples of one or more embodiments. The embodiments may be realized without one or more of the specific details, or with other methods, components, materials, etc. In other cases, known structures, materials or operations are not shown or described in detail to avoid obscuring various aspects of the embodiments. Reference to “an / one embodiment” in this specification means that a particular configuration, structure or feature described in connection with the embodiment is included in at least one embodiment. Thus, phrases such as “in an / one embodiment,” which may appear in several places in this specification, do not necessarily refer to the same embodiment. Furthermore, particular configurations, structures or features may be appropriately combined in one or more embodiments and / or associated with embodiments in a manner other than as illustrated herein, so that for example a feature exemplified herein in connection with one figure may be applied to one or more embodiments exemplified in a different figure.

[0028] The references illustrated herein are for convenience only and therefore do not delimit the extent or the scope of the embodiments.

[0029] In figure 1 , the reference number 1 designates as a whole a multilink wheel suspension system, including a suspension support frame 2 mounted on the body of the motor-vehicle, or forming part of said body.

[0030] Figure 1 illustrates a rear suspension system for a motor-vehicle with rear-wheel drive. However, the specific suspension configuration illustrated is provided purely as a non-limiting example, since the invention described here is also applicable to other types of suspension.

[0031] In one or more embodiments, the support frame 2 is formed by two horizontal crosspieces, substantially orthogonal to the longitudinal direction X of the motor-vehicle, connected to each other by two longitudinal beams.

[0032] In one or more embodiments, the support frame defines a central compartment designed for the assembly of a rear differential unit or an electric motor.

[0033] Each rear wheel of the motor-vehicle is designed to be mounted on a wheel hub 3 rotatably supported by a wheel support 4 (commonly called upright knuckle). Each wheel support 4 is connected to the support frame 2 by means of a group of oscillating elements 5. The group of oscillating elements 5 comprises at least one lower oscillating element and at least one upper oscillating element having a respective first end pivotally connected to the wheel support 2, at its respective connecting portions, by means of elastic connection elements, such as elastic bushings. The terms “upper” and “lower” refer to a vertical direction of the final assembled vehicle, orthogonal to the longitudinal direction X.

[0034] According to the present invention, whatever the configuration of said at least one lower oscillating element, it comprises a second end pivotally connected to the support frame 2.

[0035] With reference to the embodiment illustrated in figures 1 -3, said at least one lower oscillating element comprises a single lower oscillating arm 6. The lower oscillating arm 6 may comprise a seat 6' for receiving an elastic air spring device (not illustrated) of the suspension.

[0036] With reference to the illustrated example, the lower oscillating arm 6 has a first end 7 connected to a lower connecting portion 4’ of the wheel support 4. According to a non-limiting preferred feature, the first end 7 is also connected to a further portion of the wheel support 4” by means of an additional connecting rod 8.

[0037] Still with reference to the embodiment illustrated in figures 1 -3, the arm 6 comprises a second end 9 defining a pair of connection points with axes substantially coinciding, provided for connection to a respective portion of the support frame 2 by means of respective elastic bushings.

[0038] As previously indicated, the suspension system 1 comprises a group of oscillating elements 5 comprising at least one upper oscillating element, wherein said at least one upper oscillating element has a first end connected to the wheel support 4.

[0039] According to an essential feature of the present invention, said at least one upper element is not directly connected to the support frame 2, since said at least one upper element comprises a second end connected to said at least one lower oscillating element by means of at least one connecting oscillating lever 10. Therefore, it will be appreciated that the suspension 1 according to the present invention has a group of oscillating elements in which only the lower oscillating elements are directly connected to the support frame 2, while the upper oscillating elements are indirectly connected to the support frame by means of at least one oscillating lever 10 directly connected to a lower oscillating element.

[0040] With reference to the embodiment illustrated in figures 1 -3, said at least one upper oscillating element comprises a pair of upper articulated rods, comprising a first upper rod 11 and a second upper rod 12 both extending substantially along a horizontal direction perpendicular to the longitudinal direction X of the motor-vehicle. The rods 11 comprise a respective first end 11 ’, 12’ connected to a respective upper connecting portion 4” of the wheel support 4.

[0041] Still with reference to the embodiment illustrated, said at least one oscillating lever 10 that connects the upper oscillating elements to the lower ones comprises a rocker lever adapted for connecting respective second ends 11 ”, 12” of the two rods 11 , 12 to the lower oscillating element.

[0042] The rocker lever comprises a first lever 10’ connected at its opposite ends to the second end 1 T of the first upper rod 11 and to the second end 12’ of the second upper rod 12. The rocker lever also comprises a second lever 10” connected at its opposite ends to the second end 12’ of the second upper rod 12 (together with the first lever 10’) and to an articulated connecting portion 13 of the lower oscillating element.

[0043] According to a further feature illustrated in particular in figure 3, the rocker lever comprises a third lever 10’” connected at its opposite ends to the articulated connection portion 13 of the lower oscillating element (together with the second lever 10”), and to a further lower connection rod 14. At an opposite end with respect to the third lever 10’”, said further lower connection rod 14 is connected to the support frame 2.

[0044] Of course, notwithstanding the principle of the invention, the construction details and the embodiments may vary widely with respect to what is described and illustrated purely by way of example, without thereby departing from the scope of the present invention as defined in the attached claims.

Claims

CLAIMS1. Motor-vehicle comprising a multi-link wheel suspension system (1 ), including:- a suspension support frame (2),- a wheel support (4) for each wheel of the vehicle axle on which said suspension system (1 ) is provided, wherein said wheel support (4) is connected to the support frame (2) by means of a group of oscillating elements (5),- wherein said group of oscillating elements (5) comprises at least one lower oscillating element (6) and at least one upper oscillating element (11 , 12), having respective first ends (7, 11’, 12’) pivotally connected to the wheel support (4) in correspondence with respective lower and upper connection portions (4’, 4”),- wherein said at least one lower oscillating element (6) comprises a second end (9) connected to said support frame (2),- characterized in that said at least one upper oscillating element (11 , 12) is not directly connected to said support frame (2), and in that the group of oscillating elements includes at least one connecting oscillating lever (10) which connects said at least one upper element (11 , 12) to said at least one lower oscillating element (6).

2. Motor-vehicle according to claim 1 , characterized in that said at least one upper oscillating element (11 , 12) comprises a pair of upper articulated rods, comprising a first upper rod (11 ) and a second upper rod (12).

3. Motor-vehicle according to claim 2, characterized in that said at least one oscillating lever (10) comprises a rocker lever adapted for connecting respective second ends (11 ”, 12”) of the two rods (11 , 12) to the lower oscillating element (6).

4. Motor-vehicle according to claim 3, characterized in that the rocker lever comprises:- a first lever (10’) connected at its opposite ends to the second end (11’) of the first upper rod (11 ) and to the second end (12’) of the second upper rod (12),- a second lever (10”) connected at its opposite ends to the secondend (12’) of the second upper rod (12) and to an articulated connection portion (13) of the lower oscillating element (6).

5. Motor-vehicle according to claim 4, characterized in that the rocker lever comprises a third lever (10”’) connected at its opposite ends to the articulated connection portion (13) of the lower oscillating element (6), and to a further lower connection rod (14) connected to the support frame (2).

6. Motor-vehicle according to any of the preceding claims, characterized in that said at least one lower oscillating element (6) comprises a single lower oscillating arm having a second end (9) defining a pair of connection points with axes substantially coinciding, provided for connection to a respective portion of the support frame (2) by means of respective elastic bushings.

7. Motor-vehicle according to claim 6, characterized in that the first end (7) of the lower oscillating element (6) is also connected to a further connection portion (4”) of the wheel support (4) by means of an additional connection rod (8).

8. Motor-vehicle according to claim 6 or 7, characterized in that the suspension (1 ) comprises an elastic air spring device, and the lower oscillating arm comprises a seat (6’) for receiving a base portion of said elastic air spring device.

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