WO2011110788A1

WO2011110788A1 - Steering device for the rear axle of a motor vehicle

Info

Publication number: WO2011110788A1
Application number: PCT/FR2011/050484
Authority: WO
Inventors: Eric Palpacuer; Sébastien Lefranc; Christophe Monteil
Original assignee: Peugeot Citroën Automobiles SA
Priority date: 2010-03-11
Filing date: 2011-03-10
Publication date: 2011-09-15

Abstract

The invention relates to a rear axle which includes a crossmember (1), two longitudinal control arms (2) connected by the crossmember, hinged by the front end thereof to the bodywork of the vehicle and connected by the rear end thereof to the pivot (3) of the corresponding wheel by means of a pivot plate (23) and, for each control arm, at least one steering actuator (4) capable of rotating said wheel pivot (3) about a substantially vertical axis. The steering actuators (4) are installed inside the control arms (2), such that the presence of said steering actuators (4) does not affect the space available between the control arms (2). The invention can be used in the field of automobiles. The invention also relates to steering rear axles of automobiles. The invention further relates to methods for controlling the swivelling of motor vehicle wheels.

Description

STEERING DEVICE FOR THE REAR TRAIN OF A VEHICLE

MOTOR

The present invention relates to a steering rear axle for a motor vehicle equipped with a steering wheel control. Motor vehicles include a rear wheel steering control, also called rear wheel steering control, which acts in cooperation with the driver-controlled front wheel steering control.

A steered rear axle has two longitudinal swingarms known as "suspension arms", each of which carries a wheel at one of their ends and which are articulated at their other end to the vehicle bodywork, resilient means and dampers, which support the body, an anti-roll transverse cross member, which is elastically deformable in torsion and which is rigidly connected by its ends to the two suspension arms, and a device for controlling the turning of the rear wheels in a bend in order to improve the stability of the vehicle.

Such a rear axle structure is known, for example, from document FR 2 855 459, which describes a rear axle for a motor vehicle comprising two longitudinal oscillating arms each articulated to a wheel support at their end facing towards the rear of the vehicle. , and whose other end is articulated to the body of the vehicle. Both arms are connected by a crossbar. Each longitudinal arm is connected to the adjacent wheel support by a steering actuator extending in a direction substantially perpendicular to the corresponding longitudinal arm, the actuators being adapted to rotate each wheel support relative to a substantially vertical axis.

However, in this rear axle architecture, the location of the steering actuators on the suspension arms is an obstacle to obtaining an angular stroke of sufficient amplitude of the wheels. The object of the present invention is to provide a steerable rear axle for a motor vehicle equipped with a steering wheel control, the architecture of which leaves more availability in the space between the suspension arms so as to allow implantation in this space of various components, such as, for example, an electric powertrain, exhaust means, an auxiliary reservoir, etc.

Another object of the present invention is to provide such a steering rear axle, which is simple in design, easy to manufacture and mount, and is mechanically efficient. Finally, it is also an object of the present invention to provide such a steering rear axle, which is economical, in particular by having a reduced mass and a smaller number of constituent components for a relatively complex director function.

To achieve these aims, the present invention relates to a steering rear axle for a motor vehicle equipped with a steering wheel, comprising a cross member, two longitudinal suspension arms connected by the cross member, articulated by their front end to the vehicle body and connected, at their rear end, to the pivot of the corresponding wheel via a pivot door, and, for each suspension arm, at least one steering actuator, which is adapted to drive in rotation said pivot of the corresponding wheel with respect to a substantially vertical axis. According to the principle of the present invention, the steering actuators are located inside the suspension arms, so that the presence of said steering actuators does not affect the available volume between the suspension arms.

According to the preferred embodiment of the invention, the steering actuators are located in the portion of the suspension arms between the cross member and the end of said suspension arms directed towards the rear of the vehicle, and in that extend in directions substantially parallel - or very slightly inclined relative - to the longitudinal axis of the cross. According to the preferred embodiment of the invention also, the steering actuators are located in orifices passing through the width of the suspension arms.

Each steering actuator comprises a body and a rod displaceable along the longitudinal axis of the body and the rod of the actuator is connected to the corresponding wheel pivot via a steering rod, so that the translation of the rod of the actuator makes it possible to steer the wheel.

The steering rod is advantageously connected to the wheel pivot by means of a ball joint, and is advantageously connected in the same way to the actuator rod by a ball joint.

Preferably, the body of each steering actuator is fixed to the corresponding suspension arm by two bolts.

The two bolts extend, preferably, in a substantially vertical median plane of the corresponding suspension arm.

According to a second embodiment of the invention, each suspension arm is constituted by two half-arms, namely a front half-arm hinged to the vehicle body and a rear half-arm connected to the pivot of the corresponding wheel by via a wheel pivot door, and the steering actuator of the arm serves as a connection between the two half-arms so that the steering actuator fully participates in the mechanical strength of the rear axle.

According to the second embodiment of the invention, each half-arm is constituted by two substantially plate-shaped parts, namely an upper part and a lower part, and in that means are provided on the one and the other part, at their end facing the steering actuator, for fixing the steering actuator with the two half-arms between the lower parts and the upper parts of the half-arms. According to the second embodiment of the invention also, the fastening means between the two half-arms and the steering actuator are fastening means by screwing.

Preferably, the fixing means comprise fixing bolts, orifices on the upper part and the lower part of each of the two half-arms for the passage of said fixing bolts, said orifices being situated in the vicinity of the end facing towards the steering actuator of the upper part and the lower part of the half-arms, and corresponding orifices in the steering actuator or in a part integral with said actuator for the passage of said fixing bolts.

Also preferably, the fixing bolts are four in number, two bolts ensuring the attachment of the front half-arm on the steering actuator and two bolts for fixing the rear half-arm on the steering actuator. For each half-arm, the fixing bolts securing the half-arm to the steering actuator extend in a substantially vertical plane parallel to the longitudinal axis of the steering actuator.

The steering actuator comprises a body and a rod displaceable along the longitudinal axis of the body, and the rod is connected to the corresponding wheel pivot via a steering rod so that the translation of the rod of the actuator makes it possible to steer the wheel.

The steering link is connected to the wheel pivot via a ball joint, and is connected to the actuator stem by a ball joint, too. According to the invention, each suspension arm comprises a single steering actuator.

According to the invention also, the cross is a deformable cross. The present invention also relates to a motor vehicle with wheel steering control, which comprises a steering rear train consistent with that described above in outline.

Other objects, advantages and features of the invention will appear in the following description of a preferred embodiment, not limiting the object and scope of the present patent application, accompanied by drawings in which;

FIG. 1 is a perspective view of a motor vehicle rear half axle according to the principle of the present invention; FIG. 2 is a view from above of the rear half suspension of FIG. 1;

FIG. 3 is a front view, in section, of a steering actuator according to the principle of the present invention,

FIG. 4 is a cross sectional view along the line IV-IV of FIG. 3 of the steering actuator of FIG. 3; FIG. 5 is a top view of the rear axle architecture; director according to the present invention,

FIG. 6 schematically represents a rear half-axle of a motor vehicle equipped with a steering wheel control, according to a second embodiment of the present invention, and FIG. 7 is a perspective view. enlarged, exploded components of the suspension arm and the steering actuator of the half-rear axle of Figure 6.

Referring to the drawings of Figures 1 and 2, there is shown a rear axle director of a motor vehicle equipped with a steering wheel control. In these figures, only the right part of the rear axle - or right rear axle - is shown, the other part being symmetrical with respect to a substantially vertical plane, median of the crossbar 1 of the train and perpendicular to that- this. The X, Y and Z axes respectively represent the transverse, longitudinal and vertical directions of the vehicle.

The rear axle comprises two suspension arms, of general reference 2, oscillating, which extend substantially in the longitudinal direction Y of the vehicle. Each suspension arm 2 is connected, in a conventional manner, by its end 2A (FIG. 2) directed toward the rear of the vehicle to a pivoting door 23 (FIG. 1) on which the pivot 3 of the corresponding wheel is mounted, while the other end 2B of the suspension arm 2, facing the front of the vehicle, is articulated, in a conventional manner also to the vehicle body (not shown).

The crossbar 1, which extends in the transverse direction X of the vehicle, is an elastically deformable cross member and is rigidly connected at both ends to the two suspension arms 2.

The wheel pivot 3 is mounted, in a conventional manner also, on its pivot door 23 by means of two elastic wedges (only the upper wedge 3B is shown). The reference 3A designates the wheel bearing and the reference 12 is the brake disc.

A stop 15 and a damper 16 are mounted on the suspension arm 2. Due to the symmetry of the rear axle, only the right part of the text is described here, the left part of the train comprising the same assembled elements of the same way.

The suspension arm 2 comprises a steering actuator 4, which depends on the steering control of the front axle controlled by the driver and which, according to predetermined control laws, makes the steering of the rear wheels by moving along an axis xx ', substantially transverse or slightly inclined relative to the transverse direction X of the vehicle, a steering rod 7. According to the principle of the present invention, the steering actuator 4 is implanted inside the suspension arm 2, in an orifice 5 crossing the width of said arm, so that the presence of the steering actuator 4 n does not affect the volume available between the suspension arms 2. The steering actuator 4 is located in the portion of the suspension arm 2 between the cross member 1 and the end 2A of the arm facing the rear of the vehicle.

Referring also to Figures 3 and 4, the steering actuator 4 comprises, in a conventional manner, a main body 41 and a rod 42 extending substantially transversely to the suspension arm 2 and axially movable along an axis designated "xx '". The rod 42 can be moved by means of an electric motor, or by a hydraulic device. The free end 42a (FIG. 3) of the rod 42 is connected to an end 7a of the aforementioned steering rod 7 via a ball-and-socket joint 8. The other end 7b of the rod 7 is connected to the wheel pivot 3 via another ball joint, referenced 9.

The rod 42 of the actuator can be moved inwardly or outwardly of the vehicle according to the arrows FI and FE, respectively. These displacements cause rotation of the wheel pivot 3, therefore of the corresponding wheel. The body 41 of the steering actuator 4 is fixed to the suspension arm

2 corresponding by two bolts 10 and 1 1 (Figures 1, 2 and 4).

The two bolts 10 and 1 1 extend in a substantially vertical vertical plane of the suspension arm 2.

In this example, each suspension arm 2 comprises a single steering actuator 4. In a variant, it is possible, within the scope of the present invention, to implant a plurality of steering actuators in each suspension arm.

As shown in the drawing of FIG. 5, the present invention essentially consists in placing the steering actuators 4 inside the suspension arm 2, has the advantage of leaving available for the implantation of other components the space between the two suspension arms 2, that is to say the zones referenced Z _A v and Z _A R of the Figure 5, which are adjacent to the cross 1 and respectively located towards the front and rear of the vehicle. Referring to the drawings of Figures 6 and 7, there is shown a rear axle director of a motor vehicle according to a second embodiment of the invention. In these figures, only the right part of the rear axle - or right rear axle - is shown, the other part being symmetrical with respect to a substantially vertical plane, median of the crossbar 1 of the train and perpendicular thereto. The X, Y and Z axes respectively represent the transverse, longitudinal and vertical directions of the vehicle.

In a manner similar to the first embodiment, the rear axle comprises two generally oscillating suspension arms 20, which extend substantially in the longitudinal direction Y of the vehicle. Each suspension arm 20 is connected, in a conventional manner, by its end facing the rear of the vehicle to a wheel pivot 3 via a wheel pivot door 23, while the other end of the arm of suspension 20, directed towards the front of the vehicle, is articulated, also conventionally, to the body of the vehicle (not shown). Also conventionally, the wheel pivot 3 is mounted on the pivot door 23 by means of two elastic shims, lower and upper, collectively referenced 3B. Reference 3A designates the wheel bearing, integral with the wheel pivot 3.

The cross member 1, which extends in the transverse direction X of the vehicle, is advantageously an elastically deformable cross member and is rigidly connected at its ends 1A to the suspension arms 20.

Each suspension arm 20 comprises a steering actuator 50, which depends on the direction control of the front axle controlled by the driver and which performs, according to predetermined control laws, the steering of the rear wheels by moving along a transverse axis a steering rod 7 disposed transversely.

The steering actuator 50 comprises a main body 51 and a rod 52 extending substantially perpendicularly to the suspension arm 20 and axially displaceable relative to the body 51 along the axis designated "xx '". The rod 52 (see more particularly Figure 7) can be moved by means of an electric motor, or by a hydraulic device. The free end of the rod 52 is connected to one end of the steering rod 7 via a ball 8. The other end of the link 7 controls the rotation of the wheel pivot 3 via another ball, referenced 9.

The rod 52 of the actuator 4 can be moved inwardly or outwardly of the vehicle according to the arrows FI and FE, respectively. These displacements cause rotation of the wheel pivot 3, therefore the steering of the corresponding wheel. Because of the symmetry of the rear train, it is described in the following text only its right part, the left part of the train comprising the same elements assembled in the same way.

According to the principle of the present invention, the suspension arm 2 is constituted by two half-arms 21 and 22, namely a front half-arm 21 hinged to the vehicle body and a rear half-arm 22 rigidly connected, by welding for example, the pivot door 23 of the corresponding wheel. The steering actuator 50 serves as a link between the two half-arms 21 and 22 so that it fully participates in the mechanical strength of the rear axle.

Each half-arm 21, 22 is constituted by two substantially plate-shaped parts, namely an upper portion 21 A, respectively 22A, and a lower portion 21 B, respectively 22B. Means are provided on both sides, at their end facing the steering actuator 50, for fixing the steering actuator 50 with the two half-arms 21 and 22 between the lower parts 21 B, 22B and the upper portions 21A, 22A of the half-arms 21 and 22. These fixing means between the half-arms 21, 22 and the steering actuator 50 are fastening means by screwing. They comprise fixing bolts 60, 61, 62 and 63 and holes for the passage of said bolts in the half-arms 21, 22 and the steering actuator 50. These orifices comprise the orifices 60A, 61A of the upper part. 21A of the half-arm 21, the orifices 60B, 61B of the lower part 21B of the half-arm 21, the orifices 62A, 63A of the upper part 22A of the half-arm 22, the orifices 62B, 63B of the part lower 22B of the half-arm 22, and the corresponding orifices 60C, 61C, 62C, 63C which pass through the body of the steering actuator 50 or a part integral with said actuator.

The orifices 60A, 60B, 61A, 61B, 62A, 62B, 63A, 63B are located near the opposite ends of the half-arms 21, 22.

The two attachment bolts 60, 61 secure the front half-arm 21 to the steering actuator 50 and the two attachment bolts 62, 63 secure the rear half-arm 22 to the steering actuator 50.

For each half-arm 21, respectively 22, the bolts 60 and 61, respectively 62 and 63, ensuring the fixing of said half-arm on the steering actuator 50, extend in a substantially vertical plane parallel to the longitudinal axis "Xx" of the steering actuator 50. The suspension arm is mounted by placing the steering actuator 50 between the upper parts 21A, 22A and the lower parts 21B, 22B of the half-arms, and positioning the orifices 60A, 60B, 61A, 61B, 62A, 62B, 63A, 63B of the half-arm portions in alignment with the corresponding through-holes 60C, 61C, 62C and 63C of the actuator body. direction so as to allow the insertion of the fixing bolts 60 to 63 through the half-arms and the actuator before locking the latter on the half-arm by screwing the nuts on the threaded rods of the fixing bolts.

The present invention, which essentially consists of integrating the steering actuators 50 inside the suspension arms 20, presents the advantage of leaving more space available in the area surrounding the suspension arms so as to allow the implantation of other components.

There are other advantages to the various steering rear axle architectures described above, among which the following advantages: they make it possible to protect the steering actuators from external aggressions, such as shocks, gravelings, etc.

they are economical, because they are simple, with a reduced number of mechanical components,

they allow a gain in mass, the steering actuators themselves participating in the mechanical strength of the suspension arms,

they are of easy assembly, fast, the adjustment of the train clamp being integrated in the operation of fixing the actuators,

they are effective because the kinematic chain is simpler than that of the existing wheel control systems known from the prior art.

Of course, the present invention is not limited to the embodiments described and represented above by way of examples; other embodiments may be devised by those skilled in the art without departing from the scope and scope of the present invention.

Claims

1. Steering rear axle for a motor vehicle equipped with a steering wheel control, comprising a crossbar (1), two longitudinal suspension arms (2, 20) connected by the crossbar (1), articulated by their front end to the bodywork of the vehicle and connected by their rear end to the pivot (3) of the corresponding wheel via a pivot door (23), and for each suspension arm, at least one steering actuator (4, 50 ), which is adapted to rotate said wheel pin (3) with respect to a substantially vertical axis, said rear axle being characterized in that the steering actuators (4, 50) are located inside the steering arms. suspension (2, 20), so that the presence of said steering actuators (4, 50) does not affect the available volume between the suspension arms (2, 20).

2. Rear axle according to claim 1, characterized in that the steering actuators (4, 50) are located in the portion of the suspension arms (2, 20) between the cross member (1) and the end of said arms suspension (2) directed towards the rear of the vehicle, and in that they extend in directions substantially parallel - or very slightly inclined relative - to the longitudinal axis (Y) of the crossbar (1).

3. Rear axle according to any one of claims 1 and 2, characterized in that the steering actuators (4, 50) are located in orifices (5) extending through the width of the suspension arms (2, 20).

4. Rear axle according to any one of claims 1 to 3, characterized in that each steering actuator (4, 50) comprises a body

(41, 51) and a rod (42, 52) movable along the longitudinal axis of the body (41, 51), and in that the rod (42, 52) of the steering actuator (4, 50) is connected to the corresponding wheel pivot (3) via a steering rod (7) of such that the translation of the rod (42, 52) of the steering actuator (4, 50) makes it possible to steer the wheel.

Steering rear axle according to claim 4, characterized in that the steering rod (7) is connected to the wheel pivot (3) via a ball joint (9) and is connected to the rod the actuator (42, 52) also via a ball joint (8).

Rear axle according to one of claims 1 to 5, characterized in that the body (41) of each steering actuator (4) is fixed to the corresponding suspension arm (3) by two bolts (10, 1 1 ).

7. Rear axle according to any one of claims 1 to 5, characterized in that each suspension arm (20) is constituted by two half-arms, namely a front half-arm (21) articulated to the vehicle body and a rear half-arm (22) connected to the wheel pivot via a pivot door (23) of the corresponding wheel, and in that the steering actuator (4) of the arm serves as a connection between the two half-arms (21, 22), so that the steering actuator (4) participates in the mechanical strength of the rear axle.

8. Rear train according to the preceding claim, characterized in that each half-arm (21; 22) consists of two substantially plate-shaped parts, namely an upper part (21A; 22A) and a lower part (21A; B; 22B), and that means are provided on either side, at their end facing the steering actuator (50), for fixing the steering actuator (50) with the two half-arms (21, 22) between the lower parts (21 B, 22B) and the upper parts (21 A, 22A) of the half-arms (21, 22).

9. Rear train according to claim 8, characterized in that said fixing means between the two half-arms (21, 22) and the steering actuator (50) are fastening means by screwing.

10. Rear train according to claim 9, characterized in that said fixing means comprise fixing bolts (60 to 63), orifices (60A, 60B, 61A, 61B, 62A, 62B, 63A, 63B) on the upper part (21A, 22A) and the lower part (21B, 22B) of each of the two half-arms (21, 22 ) for the passage of said fixing bolts (60 to 63), said orifices (60A, 60B, 61A, 61B, 62A, 62B, 63A, 63B) being located in the vicinity of the end facing the steering actuator (50) of the upper part (21A, 22A) and the lower part (21B, 22B) of the half-arms (21, 22), and corresponding orifices (60C, 61C, 62C, 63C) in the steering actuator (50) or in a part secured to said actuator (50) for the passage of said fixing bolts (60 to 63).

1 1. Rear axle according to claim 10, characterized in that the fixing bolts (60 to 63) are four in number, two bolts ensuring

(60, 61) attaching the front half-arm (21) to the steering actuator (50) and two bolts (62, 63) securing the rear half-arm (22) to the steering actuator ( 50).

Rear axle according to claim 6 or 11, characterized in that the bolts (10, 11, 60, 61, 62, 63, 64) extend in a substantially vertical median plane of the suspension arm (2, 20) corresponding.

13. Rear axle according to any one of the preceding claims, characterized in that each suspension arm (2, 20) comprises a single steering actuator (4, 50).

14. Rear train according to any one of the preceding claims, characterized in that the crossbar (1) is a deformable cross.

15. A motor vehicle with wheel steering, characterized in that it comprises a steering rear train according to any one of the preceding claims.