FR2718391A1 - Anti=roll bar with lateral restraint for e.g. motor vehicles - Google Patents

Abstract

The hollow centre section (10) of the bar (1) is mounted on the chassis by bearings (3,4), and has extensions (15) joined directly or indirectly to the suspension. Shoulders on the central section (10a, b) abut on the inner surfaces of the bearings to prevent sideways movement. The centre section may be in un-machined steel, or machined to provide a pre-determined stiffness. The thickness of the extensions and the methods of assembly may be varied to include bonding of the extensions to the centre section.

Description

 The present invention relates to an anti-roll device for a motor vehicle.

 The elastic connection between the two wheels of the same train as well as the fixing of the train by means of fixing bearings (3) to the chassis of the vehicle are ensured in particular by anti-roll stabilizer bars which also make it possible to limit the inclinations of the vehicle in the turns.

 The bars have a generally substantially U-shaped profile. In some cases, however, this profile has multiple bends to conform to elements of the engine, chassis or suspension. This profile consists of a substantially horizontal central section made integral with the chassis by means of fixing bearings which extends on either side, via sections bent by two branches substantially perpendicular to said central section. The perpendicular branches are, in the lower part, connected, directly or indirectly to wheels.

 The bars work in torsion and in bending to limit the heeling of the vehicle; the branches of the profile moving vertically in opposite directions.

 The combination of the stresses resulting from this deformation gives a maximum equivalent stress in the immediate vicinity of the bent sections which are precisely the zones where the bearings are fixed.

 In addition, these bars tend to undergo a transverse sliding (called path) oriented laterally on one side or the other of the chassis.

 The stresses generated during the elastic work of these bars are not uniformly distributed but located in the bent areas and in the areas where the bearings are positioned. However, these zones are precisely those where it is necessary to avoid any tracking and the concentration of stresses which reigns there conditions the choice for the whole bar of a given surface condition and of a steel grade.

 In addition, the bar diameters vary depending on the type of vehicle, which requires as many different bearings.

 The present invention aims to solve these technical problems satisfactorily.

This object is achieved by means of an anti-roll device for a motor vehicle comprising a stabilizing bar consisting of a substantially straight central section made integral with the chassis by means of fixing bearings and which is extended on both sides by means of sections bent by two substantially perpendicular branches connected at the bottom, directly or indirectly to wheels, characterized in that at least the zones corresponding to the position of the bearings have a reduced external diameter delimiting with the central section of the shoulders against which the blanks internal lateral bearings come to a stop
According to an advantageous characteristic, the branches of the bar and the bent sections also have a reduced outside diameter over their entire length.

 According to another characteristic, the central section of the bar is of raw steel not machined in the zone located between the bearings.

 According to another characteristic, the zones of reduced diameter are each provided with a rigid ring forming a spacer between the internal lateral blanks of the bearings and the shoulders.

 According to yet another characteristic, said rings are made in two parts assembled by gluing and have, once placed on the bar, an outer diameter greater than that of the central section between the two shoulders to provide the internal blanks of the bearings with faces larger area support.

 According to an alternative embodiment, said rings include a peripheral groove whose dimensions are determined to accommodate a bearing therein, thus forming a support spacer for said bearing opposite said bar.

 According to a particular embodiment, said rings are not fixed on the bar and can rotate freely around said bar.

 According to a particular embodiment, the bar consists of a hollow tube.

 According to another variant, the zones of reduced diameter are preferably produced by machining prior to the bending of the bent sections.

It is also possible to provide for these zones by hammering or shrinking
The shoulders are preferably with straight edges, but according to other variants, provision is made for them with inclined or curved edges.

 The present invention provides a simple and economically advantageous solution. In fact, the bar is only partially machined and the additional cost of machining is largely offset by the gain per kilogram, taking into account the price differences between raw steel and machined steel.

 However, a bar according to the present invention can also be entirely machined but with a varied succession of diameters, for example any diameter constant or not constant in the branches, a reduced diameter in the two landing zones so as to create the two shoulders necessary for the retention of the path and a larger diameter in the central section but, if necessary, variable so as to obtain a specific behavior in torsion.

 In addition, the present invention allows standardization of the bearings whatever the desired stiffness for the anti-roll effect and therefore whatever the diameter of the bar.

 It suffices to effect a reduction in diameter in the area of the bearings always leading to the same single diameter fixed once and for all and by providing various diameters for the free area of the central section.

The invention will be better understood on reading the description which follows, accompanied by the drawings in which:
- Figures la and lb show top views of a bar according to the invention respectively before and after bending;
- Figure 2 shows a top view of an embodiment of the device of the invention with the bar and its fixing bearings;
- Figure 3 shows a cross-sectional view along AA of the device of Figure 3;
- Figure 4 shows a half view in longitudinal section of an alternative embodiment of the bar according to the invention;
- Figure 5 shows a half view in longitudinal section of another embodiment of the device of the invention; and,
- Figure 6 shows a half view in longitudinal section of a third embodiment of the invention.

 The stabilizer bar 1 shown in FIG. 1 in its rough state comprises two end sections 11 and 12 and a central section 10 aligned. It can be in solid or tubular form (Figure 4). The end sections 11 and 12 are machined or produced more generally with a reduced diameter d relative to the diameter D of the central section 10, thereby delimiting symmetrical shoulders 10a, 10b with straight edges. The length of the end sections 11,12 of reduced diameter d, is determined so as to be able to produce by bending the elbow sections 15,16 extending by branches 17,18 substantially perpendicular to the rectilinear central section as shown in Figure lb .

 The areas between the bent sections 15,16, and the central section 10 form the landing areas 13,14, that is to say the areas where the bearings 3,4 for fixing to the chassis C will be positioned. 17,18 are intended to be optionally connected by forged ends 17a, 18a, either directly or indirectly to wheels (not shown).

 The device of the invention as shown in Figures 2 and 3 comprises a stabilizer bar 1 of the type of that of Figure lb on which are fitted or assembled bearings 3,4 for fixing to the chassis C of the vehicle.

 To this end, the reduced diameter d of the bearing zones 13,14 is adapted to the internal diameter of the bearings 3,4.

 The shoulders 10a, 10b located at the junction between the central section 10 and the landing zones 13, 14 have here a slight curvature.

 The bearings 3,4 are mounted on either side of the central section 10 and their internal lateral blanks 30,40 abut by pressing against the shoulders 10a, 10b in particular when the bar 1 is caused to slide laterally in the direction Y + or Y-.

 The central body 10 of the bar 1 is either remained in raw steel not machined, or machined itself to a constant or variable diameter D according to a profile defined as a function of the torsional stiffness sought by the bar 1. In FIG. 2 , there is shown in dotted lines a possible machining variant, in double cone, which has the distinction of retaining at each of the two ends 10a and 10b a diameter D greater than the diameter d of the respective bearing zones 13 and 14 '.

 As illustrated in section in FIG. 3, the bearing 3 consists of a central sleeve 31 of rubber or plastic which is split longitudinally to be fitted by fitting on the bearing zone 13 in lateral support against the shoulder 10a of the section central 10.

 The sleeve 31 is capped by a metal collar 32 which is fixed by its flanges 32a, 32b on the chassis C. The fixing of the flanges 32a, 32b on the chassis allows the elastically deformable sleeve 31 to be tightened in contact with the bar 1.

 The device shown in FIG. 5 further comprises, on each side of the central section 10, a rigid ring 2.

 The rings 2 are mounted by fitting onto the zones 13, 14 of reduced diameter between the internal lateral blanks 30, 40 of the bearings 3, and the shoulders 10a, 10b, thus ensuring the role of spacers.

 The outer diameter of the rings 2 is greater than that of the central section 10 between the shoulders 10a, 10b so as to provide the internal blanks 30, 40 of the bearings 3.4 with bearing surfaces of greater surface area than that of the shoulders.

 The outside diameter of the rings 2 may possibly be greater than the outside diameter of the cylindrical part of the sleeve 31 of the bearings.

 In FIG. 6, the rigid ring 2 has a peripheral groove 20, the dimensions of which are determined to accommodate the bearing 3 therein and thus form a support spacer between the bearing 3 and the bearing zone 13 of the bar 1. Under these conditions, the bearing 3 has no direct contact either with the landing zones 13, 14 or with the shoulders 10a, 10b.

 In this configuration, one can choose either to have the spacer ring 2 both bonded to the bearing 3 and to the bar 1 in its bearing zone 13, or to have bonding only between the ring 2 and the level 3.

In the first case, there is no relative rotational movement possible between the ring 2 and the bearing zone 13. In the second case, a rotational movement by sliding is possible. However, in both cases, the movement along Y + or Y- is prohibited thanks to the shoulders 10a (and 10b not shown).

Claims (14)

 1. Anti-roll device for a motor vehicle comprising a stabilizing bar (1) consisting of a central section (10) substantially rectilinear made integral with the chassis (C) by means of fixing bearings (3,4) and which extends from on both sides via bent sections (15,16) by two branches (17,18) substantially perpendicular connected in the lower part, directly or indirectly to wheels, characterized in that at least the zones (13,14) corresponding to the position of the bearings (3,4) have a reduced external diameter (d) delimiting with the central section (10) the shoulders (îOa, 10b) against which the internal lateral blanks (30,40) of the bearings (3, 4) come into abutment.  2. Device according to claim 1, characterized in that the branches (17,18) and the bent sections (15,16) also have an outer diameter reduced over their entire length.  3. Device according to claim 1 or 2, characterized in that the central section (10) of the bar (1) is made of unworked raw steel.  4. Device according to claim 1 or 2, characterized in that the central section (10) of the bar (1) is machined to a diameter or according to a profile corresponding to a torsional stiffness determined for said bar (1).  5. Device according to claim 3 or 4, characterized in that the zones (13,14) of reduced diameter are each provided with a rigid ring (2) forming a spacer between the internal lateral blanks (30) of the bearings (3) and the shoulders (lOa, îOb).  6. Device according to claim 5, characterized in that said rings (2) are made in two parts assembled by gluing and have after installation an outer diameter greater than that of the central section (10) between the two shoulders (10a, 10b) to offer the internal blanks (30,40) of the bearings (3,4) of the bearing surfaces of larger area.  7. Device according to claim 5 or 6, characterized in that said rings (2) have a peripheral groove (20) whose dimensions are determined to accommodate a bearing (3,4) thereby forming a support spacer for said bearing opposite said bar (1).  8. Device according to claim 7, characterized in that the ring (2) is glued to the landing zone (13,14) thereby preventing any relative rotational movement between said ring (2) and said zone (13,14) .  9. Device according to claim 7, characterized in that the ring (2) is simply fitted on the landing zone (13,14) allowing a relative rotational movement between said ring (2) and said zone (13,14) .  10. Device according to one of the preceding claims, characterized in that said bar (1) consists of a hollow tube.  11. Device according to one of the preceding claims, characterized in that the zones (13,14) of reduced diameter are produced by machining prior to the bending of the bent sections (15,16).  12. Device according to one of the preceding claims, characterized in that said shoulders (10a, îOb) are with straight edges.  13. Device according to one of claims 1 to 11, characterized in that said shoulders (10a, 10b) are with inclined edges.  14. Device according to one of claims 1 to 11, characterized in that said shoulders (10a, 10b) are with curved edges.