Motor-vehicle suspension equipped with an adjustment unit to vary the camber angle

Abstract

A motor-vehicle suspension (1) comprising: - a lower transversal oscillating arm (3), - an upper transversal oscillating arm (4), - a wheel upright (5) coupled above and below to said arms (3, 4), - wherein said upper arm (4) comprises a first end (4') pivotally connected to an upper portion (5') of the wheel upright (5) by means of a ball joint (7), and a second end (4") pivotally connected to a portion of the vehicle frame, - wherein said upper portion (5') comprises a hollow portion defining a seat (8) within which an adjustment unit (9) adapted to vary the camber angle of said wheel (2) is mounted.

Description

[0001] “Motor-vehicle suspension equipped with an adjustment unit to vary the camber angle”

[0002] ****

[0003] TEXT OF THE DESCRIPTION

[0004] Field of the invention

[0005] The present invention generally refers to motor-vehicles and more particularly concerns a motor-vehicle suspension comprising, in association with a corresponding wheel:

[0006] - a lower transversal oscillating arm,

[0007] - an upper transversal oscillating arm,

[0008] - a wheel upright coupled above and below to said arms,

[0009] - wherein said upper arm comprises a first end pivotally connected to an upper portion of the wheel upright by means of a ball joint, and a second end pivotally connected to a portion of the vehicle frame,

[0010] - an adjustment unit adapted to vary the camber angle of said wheel.

[0011] Prior art

[0012] As is widely known to the expert technician in the field, the camber of a motor-vehicle wheel is the angle formed between a vertical plane orthogonal to the road surface and a plane passing through the center line of the wheel, i.e. the inclination of the wheels. This angle is established during the vehicle design phase, to allow the tires to have an optimal contact surface. The camber is positive when the upper part of the wheel tends to position itself outwards with respect said vertical plane, while it is negative when the upper part of the wheel tends to position itself towards the inside. Incorrect camber values (for example too positive) inevitably cause premature tire wear.

[0013] Document US 6 557 872 B1 describes a solution having the features indicated at the beginning of this description.

[0014] According to a technique known per se, the adjustment of the camber angle is carried out during the assembly of the vehicle, by activating specific adjustments of the suspension arms. For example, in the case of a double wishbone suspension, the lower arm can be provided with an eccentric screw adjustment element connected to an element of the frame, adapted to vary the wheel camber. However, this solution presents some drawbacks, including that of modifying relevant kinematic points of the suspension following the adjustment of the camber, thus varying the dynamic behavior of the vehicle independently of the applied camber angle adjustment.

[0015] The need is therefore felt to propose an improving solution that can overcome said drawbacks.

[0016] Object of the invention

[0017] The object of the present invention is to overcome the technical problems previously described.

[0018] In particular, an object of the present invention is to provide a motorvehicle suspension and a related camber angle change unit which allows effective adjustment to be carried out without changing the position of further kinematic points of the vehicle suspension.

[0019] A further object of the invention is to implement this solution with relatively simple and low-cost means.

[0020] Summary of the invention

[0021] The object of the present invention is achieved by a suspension having the features forming the subject of one or more of the following claims, which form an integral part of the technical teaching provided here in relation to the invention.

[0022] In particular, the object of the invention is achieved by a motorvehicle suspension comprising, in association with a corresponding wheel:

[0023] - a lower transversal oscillating arm,

[0024] - an upper transversal oscillating arm,

[0025] - a wheel upright coupled above and below to said arms,

[0026] - wherein said upper arm comprises a first end pivotally connected to an upper portion of the wheel upright by means of a ball joint, and a second end pivotally connected to a portion of the vehicle frame,

[0027] - wherein said upper portion comprises a hollow portion defining a seat within which an adjustment unit adapted to vary the camber angle of said wheel is mounted,

[0028] - said adjustment unit comprising a main body having a hole receiving said ball joint and a fastening element integrated with said main body, - said fastening element comprising a screw oriented transversally with respect to the axis of said hole, and a washer associated with a head portion of the screw, the center of the washer being not aligned with the axis of the screw,

[0029] - wherein, following the rotation of the screw, the camber angle is adjusted solely through an oscillation of the upper portion of the wheel upright towards the inside or outside of the vehicle with respect to a vertical plane, by maintaining a stationary position of the ball joint, the upper arm and the lower arm.

[0030] The invention is also directed to a method for varying the camber angle of a motor-vehicle wheel as indicated in the attached claim 5.

[0031] Brief description of the figures

[0032] Further features and advantages of the invention will emerge from the following description with reference to the attached drawings, provided purely by way of non-limiting example, in which:

[0033] - figure 1 is a schematic front view of a wheel suspension, according to a preferred embodiment of the present invention,

[0034] - figure 2 is an enlarged scale view of some components illustrated in the previous figure, and

[0035] - figures 3 and 4 are further enlarged scale views illustrating the suspension of the previous figures with different camber angles.

[0036] Detailed description of multiple embodiments

[0037] The following description illustrates various specific details aimed at an in-depth understanding of examples of one or more embodiments. The embodiments can be achieved 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. The reference to “an / one embodiment” in this description is to indicate that a particular configuration, structure or feature described in connection with the embodiment is included in at least one embodiment. Therefore, phrases such as “in an / one embodiment”, possibly present in different points in this description, do not necessarily refer to the same embodiment. Furthermore, particular conformations, structures or features can be combined appropriately in one or more embodiments and / or associated with the embodiments in a different way from how illustrated here, so for example a feature exemplified here in relation to a figure may be applied to one or more embodiments exemplified in a different figure.

[0038] The references illustrated here are for convenience only and therefore do not delimit the extent of protection or the scope of the embodiments.

[0039] It is specified that in the remainder of this description only the elements useful for understanding the invention are described, taking it for granted - for example - that the wheel suspensions of a motor-vehicle, which include the components illustrated in the attached drawings, include all the elements themselves known to function.

[0040] In figure 1 , reference 1 indicates a motor-vehicle suspension according to the present invention. Note that the terms upper, lower, vertical and transversal refer to the assembled suspension configuration as shown in figure 1.

[0041] The suspension 1 comprises - in association with a corresponding motor-vehicle wheel 2 - a lower transversal oscillating arm 3, an upper transversal oscillating arm 4, a wheel upright 5 arranged for connection to a wheel 2 and an elastic-damping unit 6.

[0042] The lower transversal arm 3 comprises a first end pivotally connected to the wheel upright 5 at a lower portion thereof, and a second end pivotally connected to a portion of the vehicle frame (not shown).

[0043] The upper transversal arm 4 comprises a first end 4’ pivotally connected to an upper portion 5’ of the wheel upright 5, and a second end 4” pivotally connected to a portion of the vehicle frame (not shown). In accordance with the suspension architecture illustrated in figure 1 , the upper transversal arm 4 has a general triangular shape, including a pair of rods which diverge from the first end 4’ and extend horizontally towards the inside of the vehicle for connection with the frame. The upper part of the elasticdamping unit 6 is spaced in the space created between the rods that form said upper transversal arm 4.

[0044] The first end 4’ of the upper arm 4’ comprises a pivot element in the form of a ball joint 7 for the pivotal connection with the upper portion 5’ of the wheel upright 5. According to the illustrated embodiment, the ball joint 7 has an axis oriented substantially along the vertical direction of the vehicle.

[0045] Figure 2 is an enlarged scale view illustrating the end part of the upper portion 5’ of the wheel upright 5, which can be connected to the pivot element 7.

[0046] According to the present invention, at the end part of the upper portion 5’ there is a seat 8 in which an adjustment unit 9 adapted to vary the camber angle of the wheel 2 is mounted. The adjustment unit 9 comprises a main body 9’ engaged within said seat 8, on which a hole 10 is made to receive the pivot element 7. The adjustment unit 9 also comprises a fastening element 11 integrated into the main body 9’. The fastening element 11 comprises a screw oriented transversally with respect to the axis of said hole 10, and a washer 1 T associated with a head portion of the screw, the center of the washer being not aligned with the axis of the screw.

[0047] In other words, the fastening element 11 is provided with an eccentric member suitable for allowing a translational movement of the upper portion 5’ of the upright 5 following the rotation of the screw itself. It will therefore be appreciated that following the rotation of the screw, the camber angle undergoes a variation solely through the oscillation of the upper portion 5’ of the wheel upright 5 towards the inside or outside with respect to the vertical. The ball joint and the main body 9’ of the adjustment unit 9 remain stationary during the rotation of the screw, while the end part of the wheel upright 5 with the seat 8 carries out a translation movement 8. The seat 8 is therefore shaped to enable this translation movement, comprising two opposite abutment end surfaces against which the main body 9’ can selectively come into contact, following the rotation of the screw in a respective direction.

[0048] Thanks to these characteristics, the variation of the camber angle can advantageously be carried out without changing the position of further characteristic points of the suspension, such as for example the position of the ball joint 7, the position of the upper arm 4 and the position of the lower arm 3.

[0049] From this perspective, figures 3, 4 illustrate respective camber angles obtained following the operation of the adjustment unit 9: in figure 3 there is a negative camber angle (vertical axis indicated with I and axis II passing through the center line of the wheel 2) with the upper part of wheel 2 inclined inwards with respect to the vertical axis I; in figure 4 there is a positive camber angle with the upper part of wheel 2 inclined outwards with respect to the vertical. According to a further feature of the invention, the adjustment unit 9 can comprise an electromechanical actuator which, suitably activated following a control signal imparted by an electronic control unit, adjusts the wheel camber during vehicle dynamics, depending on the maneuvers performed, the driver’s driving choices and the road profile. Of course, notwithstanding the principle of the invention, the construction details and the embodiments may vary widely with respect to what has been described and illustrated purely by way of example, without thereby departing from the scope of the present invention.

Claims

CLAIMS1. A motor-vehicle suspension (1 ) comprising, in association with a corresponding wheel (2):- a lower transversal oscillating arm (3),- an upper transversal oscillating arm (4),- a wheel upright (5) coupled above and below to said arms (3, 4),- wherein said upper arm (4) comprises a first end (4’) pivotally connected to an upper portion (5’) of the wheel upright (5) by means of a ball joint (7), and a second end (4”) pivotally connected to a portion of the vehicle frame,- wherein said upper portion (5’) comprises an adjustment unit (9) adapted to vary the camber angle of said wheel (2),- wherein said upper portion (5’) comprises a hollow portion defining a seat (8) within which said adjustment unit (9) is mounted,- wherein said adjustment unit (9) comprises a main body (9’) having a hole (10) receiving said ball joint (7) and a fastening element (11 ) integrated with said main body (9’),- wherein said fastening element (11 ) comprises a screw oriented transversally with respect to the axis of said hole (10), and a washer (11 ’) associated with a head portion of the screw, the center of the washer being not aligned with the axis of the screw,- wherein, following the rotation of the screw, the camber angle is adjusted solely through an oscillation of the upper portion (5’) of the wheel upright (5) towards the inside or outside of the vehicle with respect to a vertical plane, by maintaining a stationary position of the ball joint (7), the upper arm (4) and the lower arm (3).

2. The suspension (1 ) according to claim 1 , wherein the seat (8) is shaped to enable said oscillating movement, comprising two opposite abutment end surfaces against which the main body (9’) can selectively come into contact, following the rotation of the screw in a respective direction.

3. The suspension (1 ) according to claim 1 , wherein the upper transversal arm (4) has a general triangular shape, including a pair of rodsthat diverge from the first end (4’) and extend horizontally towards the inside of the vehicle for connection to the frame.

4. The suspension (1 ) according to claim 1 , wherein the adjustment unit (9) comprises an electromechanical actuator operatively connected with the fastening element (11 ), for adjusting the wheel camber during vehicle dynamics.

5. A method for varying the camber angle of a motor-vehicle wheel (2) including:- providing a suspension (1 ) according to any of the preceding claims, - actuating said adjustment unit (9) to vary the camber angle solely through an oscillation of the upper portion (5’) of the wheel upright (5).

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