WO2012175844A1

WO2012175844A1 - Vehicle suspension arm

Info

Publication number: WO2012175844A1
Application number: PCT/FR2012/051324
Authority: WO
Inventors: Philippe Minaud
Original assignee: Renault S.A.S.
Priority date: 2011-06-20
Filing date: 2012-06-13
Publication date: 2012-12-27
Also published as: FR2976519A1; FR2976519B1

Abstract

The invention relates to a device for connecting a wheel to a motor vehicle structure including an axle (2), comprising at least two arms (2a) that are substantially longitudinal relative to the vehicle, one end (2b) of each of which is to be connected to the vehicle structure, and a steering knuckle holder (3) supporting a steering knuckle (4) along a first substantially transverse axis (Y1), wherein the wheel and two means (5, 6) for connecting to the longitudinal arm (2a) are rotatably mounted onto said steering knuckle about second and third substantially transverse axes (Y2, Y3), respectively, said first, second, and third transverse axes (Y1, Y2, Y3) being located in a single plane (YZ). The connecting device includes means (3d, 12b) for limiting the rotation of the steering knuckle (3) about the second substantially transverse axis (Y2) in the event the first connecting means (5) breaks.

Description

VEHICLE SUSPENSION ARM

The present invention relates to the field of motor vehicles and, in particular the devices for connecting a wheel to the structure of the vehicle.

More particularly, the invention relates to connecting devices comprising an axle and a rocket door.

The term "axle" means any part arranged transversely under a vehicle to bear the weight, and whose ends cooperate with the wheel hub.

Generally, a motor vehicle comprises a body, wheels resting on the ground and an axle linking the body to the wheels. This axle comprises for each wheel a wheel spindle on which said wheel is rotatably mounted about a transverse axis having a threaded end, called "wheel rocket". The axle also comprises a substantially longitudinal arm connected to the body by a first end and means for connecting the rocket door to a second end of the arm opposite the first end, and a substantially transverse deformable cross member of the respective longitudinal arms of the two wheels .

When the wheel encounters an obstacle on the ground, this wheel undergoes a force having a vertical component and a longitudinal component. This obstacle may be an irregularity of the ground, a stone, a hole or any other object or formation protruding or recessed from the ground. The vertical component is damped by the suspension of the vehicle before being transmitted to the box and is therefore not felt by the passengers. The longitudinal component is however not depreciated by the suspension and is felt as a shock by the passengers of the vehicle.

It is known to provide that the axle allows a substantially longitudinal displacement of the wheel center when the wheel meets an obstacle, so as to improve the comfort of passengers. For this purpose, we choose an axle whose kinematics imposes the wheel center, in case of obstacle, a rotational movement about a transverse axis located near the point of contact between the wheel and the ground. Reference can be made to document FR 2875742, which describes a motor vehicle provided with means for guiding each rocket door in displacement on a longitudinal trajectory comprising a guiding member disposed on the arm and cooperating with oblong holes located on the wheel axle door. . However, such a system is difficult to implement and requires a modification of the vehicle structure. In addition, although the longitudinal displacement of the wheel center, called "wheel recoil", is guided, the guide means do not allow to properly dampen the longitudinal component.

Furthermore, in case of rupture of the guide means, the wheel axle, under the effect, for example braking, will no longer be locked in rotation about the transverse axis located near the point of contact. Rotation of the wheel axle could damage the braking system, eg tearing off the brake hose, in which case the wheel would become out of control with the vehicle.

An object of the invention is therefore to overcome these disadvantages and to provide a device for connecting a wheel to the structure of a motor vehicle to improve the damping of the longitudinal component, easy to implement.

Another object of the invention is to secure the rotation of the wheel axle door in case of breakage of one of the guide means.

According to one embodiment, the object of the invention is a device for connecting a wheel to a motor vehicle structure comprising an axle comprising at least two substantially longitudinal arms relative to the vehicle, one end of which is intended to be connected to the vehicle structure and a rocket bearing wheel support, with a first substantially transverse axis, on which is rotatably mounted the wheel and two connecting means to the longitudinal arm, with respectively a second and third substantially transverse axes. Said first, second and third transverse axes are arranged in the same plane.

The connecting device comprises means for limiting the rotation of the rocket door around the second substantially transverse axis, in case of breakage of the first connecting means.

Thus, during the breaking of the first connecting means, the rotation of the rocket door about the third transverse axis is limited and avoids damage to the parts. According to one embodiment, the rocket door comprises a bore in which is mounted the first connecting means, the bore extending transversely to the longitudinal arm of the axle beyond the first connecting means, forming a stop.

The addition of material on the wheel stub axle coming beyond the first connecting means acts as a stop in case of breakage of the fastening screw of the first connecting means.

In the case where the rocket door is mounted directly on the longitudinal arm of the axle, the longitudinal arm comprises an annular portion, projecting towards the rocket door, of diameter substantially smaller than the diameter of the bore of the rocket door, in order to cooperate with the abutment of the wheel axle door and to reinforce the rotational locking of the wheel stub axle around the third transverse axis in case of rupture of the first connecting means.

The annular portion may comprise two stops arranged symmetrically with respect to a substantially vertical axis perpendicular to the transverse axes.

The rocket door can be mounted on the longitudinal arm by means of a rocket plate, the rocket plate comprises a stop on each side cooperating with the annular rim of the rocket door, to enhance the limitation in rotation of the rocket door wheel around the third transverse axis in case of rupture of the first connecting means.

Advantageously, the first connecting means is disposed between the wheel spindle and the second connecting means.

The wheel axle, the wheel spindle and the connecting means form, for example, a single subassembly mounted on the longitudinal arm of the axle. Such a subset allows a reduction in the mass and dimensioning of the connecting device. The rocket board can be part of this subset.

The first connecting means may comprise an elastic or hydro-elastic articulation mounted on the wheel axle door and a fastening screw to the axle arm via or not the rocket plate. A hydroelastic joint may comprise, for example, an inner ring, an outer ring, a resilient member disposed between said rings and a damping liquid. The elastic or hydro elastic joint is mounted on the screw of fastening connected to the vehicle structure via the axle.

Advantageously, the second connecting means comprises a pivot joint with a third transverse axis parallel to the first and second transverse axes so as to pivot the wheel axle door about said third transverse axis and to guide it in displacement on a substantially longitudinal curved trajectory .

According to a second aspect, the invention relates to a motor vehicle comprising a body, at least two wheels resting on the ground and a connecting device as described above.

Other objects, features and advantages of the invention will become apparent on reading the following description, given solely by way of nonlimiting example, and with reference to the appended drawings in which:

- Figure 1 is a schematic perspective view of a connecting device according to one embodiment;

- Figure 2 is a sectional view of a connecting device according to Figure 1;

- Figure 3 is a sectional view of a connecting device according to another embodiment.

As illustrated in Figure 1, a device for connecting a wheel to a motor vehicle (not shown), referenced 1 as a whole, comprises an axle 2 connected to the vehicle structure and a wheel flap door 3 The axle 2 comprises substantially longitudinal arms 2a connected to the body of the vehicle (not shown) by a first end 2b, a deformable cross member 2c substantially transverse solidarity of two respective longitudinal arms 2a of the two wheels (not shown). The axle 1 is fixed, at one end 2d opposite the first end 2b, to the wheel spindle 3 supporting a wheel spindle 4, with a first substantially transverse axis Y1 and two connecting means 5, 6 to the longitudinal arm 2a . The first connecting means 5 has a second substantially transverse axis Y ₂ and the second connecting means 6 has a second substantially transverse axis Y ₃ . The wheel spindle 4 and the connecting means 5, 6 are arranged on a same substantially vertical axis Z, perpendicular to the longitudinal axis X of the vehicle. In other words, the first, second and third transverse axes Y ₁ , Y ₂ , Y 3 are mutually parallel and arranged in the same plane YZ comprising the substantially vertical axis Z. The plane YZ corresponds to the section plane of the connecting device of FIG. 2 .

As illustrated in FIG. 2, the connecting device 1 is intended to connect a wheel (not shown) via a wheel hub 7 to a structure of a motor vehicle, such as a chassis. . The wheel spindle 3 also includes fins 3a located in the upper part of the wheel spindle 3 for fixing the brake calipers (not shown).

The wheel spindle 4, of transverse axis Y _ls is a tapered shaft, inserted into a bore 3b of the wheel spindle door 3. The wheel spindle 4 and the wheel spindle 3 can also be combined into one. room.

Wheel spindle 4 supports tapered roller bearings

8 of the wheel hub 7 and has a threaded end 4a cooperating with an adjusting nut 9 for adjusting the tapered roller bearing 8. The wheel spindle 4 is thus inserted into the bore 7a of the wheel hub 7 and the wheel (not shown) is thus rotatably mounted on the wheel spindle 4. A protective cover 10 may be arranged at one end of the bore 7a of the wheel hub 7 in order to prevent the entry of pollutants into the wheel hub. bore 7a and in the tapered roller bearing 8.

As illustrated in FIGS. 1 and 2, a sensor support 1 1, of axis Y 1, is arranged on the wheel axle 3. The sensor support 1 1, of generally circular shape, comprises a notch 11 for to cooperate with a sensor 1 1b rotation of the wheel.

In the example shown, the wheel spindle 3 directly attached to the longitudinal arm 2a of the axle 1. The longitudinal arm 2a comprises at one end 2d a first attachment portion 12 of the first connection means 5 and a second attachment portion 13 of the second connection means 6.

The first connecting means 5 having a transverse axis Y ₂ parallel to the axis Y ₁ comprises a hydroelastic articulation comprising an inner ring 5a, an outer ring 5b and an elastic element 5c, for example rubber, disposed between the inner ring 5a and outer 5b. The hydro-elastic joint is tightly mounted in a bore 3c located on the wheel spindle door 3. The bore 3c extends transversely to the longitudinal arm 2a beyond the first connecting means 5 by an annular flange 3d. A screw assembly 14 and washer 15 maintains the translation along the transverse axis Y ₂ of the hydro-elastic joint. Indeed, the cylindrical portion 14a of the screw 14 is inserted into the bore 5d of the inner ring 5a and the threaded portion 14b of the screw 14 is screwed into a tapping 12a formed in the first fastening portion 12 of the longitudinal arm 2a . Alternatively, one could provide to fix the rocket door 3 on the arm 2a via a rocket plate (not shown). The hydro-elastic connection makes it possible to control and limit the deflection of the wheel axle 3. However, the use of an elastic or hydro-elastic articulation different from that described could be envisaged insofar as the effect is similar.

The second connecting means 6, of transverse axis Y ₃ parallel to the axes Y ₁ and Y ₂ , comprises a pivot connection made by a bearing 16, such as for example a tapered roller bearing supported by a transverse shaft 17 having a threaded end. 17a and an end 17b having an annular flange. The tapered roller bearing 16 comprises an inner ring 16a, an outer ring 16b and one or two rows of tapered rollers 16c disposed between the rings 16a, 16b. The outer ring 16b is mounted tightly in a bore 3e, of axis Y ₃ , of the wheel spindle 3, so that the wheel spindle 3 pivots around the axis Y ₃ . The threaded end 17a of the transverse shaft 17 cooperates with a nut 17c and the flanged end 17b cooperates with the second attachment portion 13 of the arm 2a in order to ensure the connection between the wheel axle 3 and the arm longitudinal 2a. A protective cover 18 may be arranged at one end of the bore 3 of the rocket door 3 to prevent pollutants from entering the tapered roller bearing 16.

Alternatively, one could consider the use of a double-row ball bearing. Alternatively, one could fix the second connecting means 6 on the arm 2a via a rocket plate (not shown).

The rocket door 3, the wheel flare 4 and the two connecting means 5, 6 form a single subassembly intended to be mounted on the vehicle structure via the longitudinal arm 2a. The rocket plate could alternatively be part of this subassembly.

The first connecting means 5 is disposed between the wheel spindle 4 and the second connecting means 6 so as to pivot the wheel spindle 3 around the transverse axis Y ₃ and to guide it in displacement on a trajectory. substantially longitudinal curve substantially along the X axis, in case of presence of an obstacle on the ground. Indeed, when the wheel encounters an obstacle on the ground, this wheel undergoes a force having a longitudinal component and a vertical component. The longitudinal component, along the X axis, applies directly to the wheel spindle, and causes a displacement of the wheel. This displacement of the wheel is called "wheel recoil". The wheel recoil, in the event of an obstacle makes it possible to reduce the forces transmitted to the wheel train of the vehicle.

The rotation of the rocket door 3 along the Y axis ₃ is authorized by the pivot connection 6 but its travel is limited by the hydro-elastic connection 5, for example of an amplitude of about 5 mm, which makes it possible to control the wheel recoil.

The first attachment portion 12 of the arm 2a further comprises an annular portion 12b projecting towards the wheel spindle door 3. The annular portion 12b is in contact with the hydro-elastic connection 5 and is surrounded by the annular flange 3 of the 3. The annular portion 12b has an outside diameter slightly smaller than the diameter of the bore 3c of the annular flange 3d. The distance between the two diameters is in a range of 5 to 7 mm depending on the characteristics of the hydro-elastic connection.

In case of breakage of the fastening screw 14 of the first connecting means 5, the annular flange 3 d associated with the addition of material 12b of the first fastening portion 12 of the longitudinal arm 2a form a means for limiting the rotation of the door wheel spindle 3 around the third transverse axis Y ₃ .

In the embodiment illustrated in FIG. 3, in which the same elements have the same references, the longitudinal arm 2a also comprises two stops 19 of generally parallelepipedal shape arranged on either side of the annular portion 12b in order to form a stop in rotation with the annular flange 3 d of the rocket door 3. The stops 1 9 are arranged symmetrically relative to the substantially vertical axis Z. As a variant, such stops could be provided on a rocket plate.

The annular flange 3 d associated with the abutments 19 of the longitudinal arm 2a form a rotation limiting means of the wheel spindle 3 around the third transverse axis Y ₃ in the event of rupture of the first connecting means 5 and in particular of the fastening screw 14.

Thanks to the pivot connection, which allows the wheel spindle to be rotated along the Y axis ₃ , the movement of the wheel spindle presents an oscillatory movement whose trajectory is an arc of a circle centered on the transverse axis Y _3. second connecting means. The more the transverse axis Y ₃ is close to the point of contact of the wheel on the ground, the more this trajectory will be longitudinal along the X axis. The bearing of the pivot link makes it possible to block the translations following all the X, Y axes. , Z, as well as the rotations along the X and Z axes, thus making it possible to adjust the camber of the wheels. The camber is the angle between the wheel and the plane perpendicular to the ground, along the Z axis. Adjusting the camber results in even tire wear.

Thanks to the invention, the damping of the longitudinal component is improved by the two connecting means arranged on the same vertical axis.

Moreover, the means of limitation in rotation make it possible to secure the rotation of the wheel axle door in case of rupture of the oscillating axis, in order to avoid damaging the structure of the vehicle.

In addition, the connecting device is easy to implement insofar as it is a pre-assembled subassembly.

Claims

1. Device for connecting a wheel to a motor vehicle structure comprising an axle (2) comprising at least two substantially longitudinal arms (2a) with respect to the vehicle, one end (2b) of which is intended to be connected to the structure of the vehicle and a spindle carrier (3) supporting a wheel spindle (4), with a first substantially transverse axis (Yi), on which is rotatably mounted the wheel and two connecting means (5, 6) to the longitudinal arm (2a ), respectively with second and third substantially transverse axes (Y ₂ , Y ₃ ), said first, second and third transverse axes (Y ₁ , Y ₂ , Y ₃ ) being arranged in the same plane (YZ), characterized in that it comprises means for limiting rotation (3d, 12b, 19) of the wheel axle holder (3) around the second substantially transverse axis (Y ₂ ), in case of breakage of the first connecting means (5).

2. Connecting device according to claim 1, wherein the rocket door (3) comprises a bore (3 c) in which is mounted the first connecting means (5), and an annular flange (3 d) extending transversely. to the arm (2a) of the axle (2) beyond the first connecting means (5), forming a radial abutment.

3. Connecting device according to claim 2, wherein the rocket door (3) is mounted directly on the longitudinal arm (2a) of the axle (2), the longitudinal arm (2a) comprising an annular portion (12b) in protruding towards the rocket door (3), of diameter substantially smaller than the diameter of the bore (3c) of the rocket door (3).

4. Connecting device according to claim 3, wherein the annular portion (12b) comprises two stops (19) arranged symmetrically with respect to a substantially vertical axis (Z) perpendicular to the transverse axes (Yi, Y ₂ , Y ₃ ).

5. Connecting device according to any one of the preceding claims, wherein the first connecting means (5) is disposed between the wheel spindle (4) and the second connecting means (6).

6. Connecting device according to any one of the preceding claims, wherein the wheel stub axle (3), the wheel spindle (4) and the connecting means (5, 6) form a single subassembly mounted on the longitudinal arm (2a) of the axle (2).

7. Connecting device according to any one of the preceding claims, wherein the first connecting means

(5) comprises an elastic or hydro-elastic articulation mounted on the wheel axle carrier (3) and a fastening screw (14) to the axle arm (2a) (2).

8. Connecting device according to any one of the preceding claims, wherein the second connecting means

(6) comprises a pivot joint with a third transverse axis (Y ₃ ) parallel to the first and second transverse axes (Y ₁ , Y ₂ ) so as to pivot the wheel axle (3) about said third transverse axis (Y ₃ ).

9. A motor vehicle comprising a body, at least two wheels resting on the ground and a connecting device (1) according to any one of the preceding claims.