FR3055878A1 - REAR TRAIN OF A VEHICLE, IN PARTICULAR A MOTOR VEHICLE - Google Patents

Abstract

The invention relates to a rear axle of a vehicle, in particular an automobile. According to the invention, the steering axis of the wheel (2) of each half-train (1) passing through the two articulated links (8, 10) of the corresponding ends of the lower arm (4) and upper (5) to wheel pivot (3) forms with an axis perpendicular to the ground a flush angle between 0 and 15 °. The invention finds its application in the field of the automotive industry.

Description

Holder (s): PEUGEOT CITROEN AUTOMOBILES SA Société anonyme.

Extension request (s)

Agent (s): PEUGEOT CITROEN AUTOMOBILES SA Public limited company.

105 / REAR TRAIN OF A VEHICLE, ESPECIALLY A MOTOR VEHICLE.

FR 3 055 878 - A1

The invention relates to a rear axle of a vehicle, in particular an automobile.

According to the invention, the turning axis of the wheel (2) of each half-train (1) passing through the two articulated connections (8, 10) of the corresponding ends of the lower (4) and upper (5) arms at wheel pivot (3) forms an angle between 0 and 15 ° with an axis perpendicular to the ground.

The invention finds its application in the field of the automobile industry.

REAR TRAIN OF A VEHICLE, PARTICULARLY A MOTOR VEHICLE [001] The invention relates to a rear axle of a vehicle, especially a motor vehicle.

In a manner known per se, many vehicles, in particular motor vehicles, are fitted with a multi-link rear axle, which makes it possible to finely adjust the parameters linked to the wheels of the train, such as parallelism, camber or even the hunt.

EP 1609631 discloses a multi-link rear axle for a motor vehicle. Each half-train of this rear axle comprises in particular two lower and upper arms arranged transversely on either side of the axis of rotation of the corresponding wheel, the upper arm being disposed above this wheel axis. This particular configuration of the rear axle makes it possible to integrate a transmission making the train powered.

[004] However, such a rear axle is not intended to be a train of steered wheels. Indeed, the turning axis of each wheel of such a train is positioned so that the turning of the wheels harms the bodywork of the vehicle.

The present invention aims to overcome the above drawbacks of the prior art.

To achieve this object, the invention relates to a rear axle of a vehicle, in particular a motor vehicle, each half of which comprises a wheel assembly fixed to a wheel pivot, a lower arm and an upper arm arranged transversely by relative to the longitudinal direction of the vehicle and the opposite ends of which are connected in an articulated manner respectively to the chassis of the vehicle and to the wheel pivot, the two lower and upper arms being arranged on either side of the axis of rotation of the wheel, a turning axis of the wheel passing through the two articulated connections of the corresponding ends of the lower and upper arms to the wheel pivot forming, with an axis perpendicular to the ground, a hunting angle of between zero and fifteen degrees.

In another feature, the lower arm of each half-train is generally triangular in shape, one top of the lower arm being connected to the wheel pivot and the other two tops being connected to the chassis of the vehicle.

In another feature, each half-train comprises a shock absorber and a suspension spring, the free ends of the spring being supported respectively against the vehicle chassis and the lower arm, the ends of the shock absorber being connected so articulated respectively to the chassis of the vehicle and to the lower arm.

In another feature, each half-train comprises a third arm arranged transversely to the longitudinal direction of the vehicle and forming a clamp link, the ends of which are connected in an articulated manner respectively to the chassis of the vehicle and to the wheel pivot to allow to carry out the sketch of parallelism of the corresponding wheel during deflections of the latter.

In another feature, the clamp link of each half-train is positioned in front of the axis of rotation of the wheel relative to the direction of movement in forward motion of the vehicle, and in that the distance separating the articulated connection between the corresponding end of the clamp link and the wheel pivot and the axis of rotation of the corresponding wheel is between sixty and one hundred and fifty mm.

In another feature, each half-train comprises a fourth arm of generally triangular shape intended to limit the travel of the corresponding wheel and disposed longitudinally to the vehicle, a top of the longitudinal arm being connected to the chassis of the vehicle and the two ends opposite the top being connected to the wheel pivot.

In another feature, each half-train comprises a rack-shaped actuator, one end of which is secured to the chassis of the vehicle and the other end of which is hingedly connected to one of the ends of the clamp link, the other end of the clamp rod being connected in an articulated manner to the wheel pivot, the actuator being able to move the clamp rod transversely so that the corresponding wheel has a rotational movement around the turning axis.

In another feature, the wheel steering angle of each half-train is between zero and five degrees.

In another feature, each half-train comprises a transverse transmission intended to drive the corresponding wheel.

The invention also relates to a motor vehicle comprising a rear axle as described above.

The invention will be better understood, and other objects, characteristics, details and advantages thereof will appear more clearly in the explanatory description which follows, made with reference to the appended drawings given solely by way of example illustrating a embodiment of the invention and in which:

- Figure 1 shows a perspective view of a rear undercarriage of the invention;

- Figure 2 shows a top view of the half-train of Figure 1;

- Figure 3 shows a side view of the half-train of Figure 1.

With reference to the figures, the rear axle of a motor vehicle will now be described.

Each half-train 1 of the rear axle of the vehicle comprises a wheel assembly mounted on a wheel pivot 3. More specifically, the wheel assembly comprises the wheel 2, the tire and the disc, capable of being driven in rotation via a bearing of the wheel pivot 3. In addition, the wheel assembly comprises a brake caliper (not shown) surrounding the wheel disc, positioned behind the wheel axle with respect to the direction of movement forward of the vehicle. In the following description, the terms in front and behind are to be understood relative to the direction of movement of the vehicle in forward gear.

Each half-train 1 also comprises at least two arms 4, 5, 16, 19 ensuring the connection between the wheel pivot 3 and the chassis 11 of the vehicle. The opposite ends of these arms 4, 5, 16, 19 are connected in an articulated manner respectively to the wheel pivot 3 and to the chassis 11 of the vehicle, preferably to a cross member of the chassis

11. These articulated connections 6, 7, 8, 9, 10, 17, 18, 20, 21 ensure the mobility of the arms 4, 5, 16, 19 relative to the chassis 11 of the vehicle and to the corresponding wheel pivot 3.

The first arm 4 of the half-train 1, said lower arm 4, is positioned transversely relative to the longitudinal direction of the vehicle, below the axis of rotation of the corresponding wheel 2, that is to say say that this lower arm 4 is positioned between the ground S on which the vehicle rests and the wheel axle. Preferably, the lower arm 4 is of generally triangular shape, a vertex of the lower arm 4 being connected to the wheel pivot 3 while the other two vertices of the lower arm are respectively connected to the chassis 11 of the vehicle and to one end of a link force recovery 24, the other end of which is hingedly connected to the chassis 11 of the vehicle, for example by means of ball or rubber joints 6, 7, 8, 25. In addition, the top of the lower arm 4 linked to the force recovery link 24 is positioned furthest back relative to the other two vertices of the lower arm 4, the straight line passing through these two other vertices being transverse to the vehicle. The function of this force recovery link 24, arranged in a direction substantially perpendicular to the plane in which the chassis 11 of the vehicle extends, will be described below.

Each half-train 1 also comprises a damper 14, the ends of which are connected in an articulated manner respectively to the body of the vehicle and on one face of the lower arm 4 opposite the chassis 11, for example by the intermediate of ball or rubber joints. In addition, each half-train 1 comprises a suspension spring 15, preferably a helical spring, the free ends of which bear respectively against the body of the vehicle and the face of the lower arm 4 located opposite the body of the vehicle. . The shock absorber 14 and the suspension spring 15 are also positioned behind the wheel axle.

In an alternative embodiment and not shown, only the front axle of the vehicle is motorized. In the embodiment shown in the figures and in the context of a rear-wheel drive or four-wheel drive vehicle, the rear axle is motorized, and each half-axle 1 comprises a transverse transmission 23 intended to drive the corresponding wheel 2 This electrical or mechanical transmission 23 is positioned in front of the damper 14 and the suspension spring 15.

The second arm 5 of the half-train 1, said upper arm, is positioned transversely relative to the longitudinal direction of the vehicle, above the axis of rotation of the corresponding wheel 2, that is to say say that the lower 4 and upper 5 arms are positioned on either side of the wheel axle. The upper arm 5 is rectilinear, or curved according to the body and the elements of the nearby train, and its opposite ends are connected in an articulated manner respectively to the wheel pivot 3 and to the chassis 11 of the vehicle, for example by pivot joints or rubber 9, 10. In addition, the upper arm 5 is positioned in front of the axis of rotation of the corresponding wheel

2.

Preferably, each half-train 1 comprises a third arm 16 arranged transversely to the vehicle and which will be described below, as well as a fourth arm 19 disposed longitudinally of the vehicle.

This fourth longitudinal arm 19 is of generally triangular shape. The first vertex of this fourth arm 19 is hingedly connected to the chassis 11 of the vehicle, while the other two vertices are hingedly connected to the wheel pivot 3, by means of links of the ball or rubber joint type 20, 21. Preferably, the connection 20 between the first vertex and the chassis of the vehicle is a rubber joint.

The fourth arm 19 is intended to limit the deflections of the corresponding wheel 2. However, during the deflection of the wheel 2, the longitudinal arm 19 also gives movement to the wheel 2 in the longitudinal direction of the vehicle, it i.e. forward or backward. This longitudinal movement of the wheel 2 of the half-train 1 consequently causes the displacement in the same direction on the one hand of the connection 8 of the lower arm 4 to the wheel pivot 3, and on the other hand of the connection 7 of the arm lower 4 than the effort recovery link 24 by means of the latter 7. The presence of the effort recovery link 24 therefore makes it possible to avoid the generation of efforts at the connections 6, 25 between the lower arm 4 and the chassis 11 of the vehicle, and also makes it possible not to affect the kinematics of the half-train 1 during the deflections of the corresponding wheel 2.

The third transverse arm 16 of each half-train 1 forms a clamp link, and its opposite ends are connected in an articulated manner, for example using ball or rubber joints 17, 18, respectively to the frame 11 of the vehicle and to the wheel pivot 3 in order to allow the sketch of parallelism of the corresponding wheel 2 to be produced during the deflections of the latter. In addition, the clamp link 16 is positioned in front of the axis of rotation of the corresponding wheel 2.

In an alternative embodiment and not shown, one of the ends of the clamp link 16 is directly connected to the chassis 11 of the vehicle, and the clamp link 16 has the sole function that described above. In the embodiment shown in the figures, the rear axle is with steered wheels, and the wheel 2 of each half-axle 1 is capable of pivoting around a turning axis 12 passing through the two articulated connections 8, 10 of the corresponding ends of the lower 4 and upper 5 arms of the wheel pivot 3. This turning axis 12 is also called the pivot axis and is located in the plane of the corresponding wheel 2.

The deflection of the wheel 2 of each half-train 1 is provided by the clamp link 16, one end of which is connected in an articulated manner, for example by a ball or rubber joint 17, at one end of a actuator 22 in the form of a rack. The other end of the actuator 22 is in turn connected to the chassis 11 of the vehicle, and the other end of the clamp link 16 is connected to the wheel pivot 3. The actuator 22 is thus able to transversely move the clamp link 16, so that the corresponding wheel 2 of the half-train 1 rotates around the turning axis 12. In addition, the distance separating the link 18 between the end of the clamp link 16 and the wheel pivot 3 and the axis of rotation of the wheel is between sixty millimeters and one hundred and fifty millimeters. This distance is fixed once and for all during the mounting of the train on the vehicle, and depends on the reduction and the travel of the actuator 22 forming a rack. Furthermore, the stroke of the actuator 22 is adjusted so that the steering angle is between zero and five degrees.

According to the invention, the hunting angle formed by the turning axis 12 and a perpendicular axis 13 on the ground is between zero and fifteen degrees. Under these conditions, the straight line passing through the turning axis intersects the ground at a point X located at a distance from the wheel 2 of between ten and forty centimeters. The slight inclination of the turning axis 12 with respect to the perpendicular axis 13 to the ground S makes it possible to turn the corresponding wheel 2 with a small variation in camber, that is to say a small variation in the 'angle formed between the perpendicular axis 13 to the ground S and the wheel plane.

The configuration as described is not limited to the embodiment described in the text and shown in the figures. It has been given only as a non-limiting example. Multiple modifications can be made without departing from the scope of the invention. So we could imagine installing the shock absorber 14 and the suspension spring 15 in front of the upper arm 5 and the wheel axle. We could also imagine installing the brake caliper at the front of the wheel disc. It is also possible to integrate the fourth transverse arm 16 forming a gripper link behind the axis of the corresponding wheel 2. It is also possible to position the triangular lower arm 4 so that the force recovery link 24 is disposed on the top of the lower arm 4 foremost with respect to its two other vertices. Alternatively, it is also possible to replace the force recovery link 24 with a rubber joint directly connecting a top of the lower arm 4 to the chassis 11 of the vehicle. The helical suspension spring can also be replaced by a transverse leaf spring fixed to the vehicle body by means of two bearings and fixed to the lower arms of the corresponding half-train by means of two links. Finally, the train according to the invention may include an anti-roll bar whose ends are connected to the wheels of the train.

Claims (10)

1. Rear axle of a vehicle, in particular an automobile, each half-axle of which (1) comprises a wheel assembly (2) fixed to a wheel pivot (3), a lower arm (4) and an upper arm (5 ) arranged transversely to the longitudinal direction of the vehicle and the opposite ends of which are hingedly connected respectively to the chassis (11) of the vehicle and to the wheel pivot (3), the two lower (4) and upper (5) arms being arranged on either side of the axis of rotation of the wheel, characterized in that a turning axis (12) of the wheel passing through the two articulated connections (8, 10) of the corresponding ends of the lower arms (4) and higher (5) to the wheel pivot (3) forms with a perpendicular axis (13) on the ground a hunting angle (") between zero and fifteen degrees. 2. Train according to claim 1, characterized in that the lower arm (4) of each half-train (1) is of generally triangular shape, a top of the lower arm (4) being connected to the wheel pivot (3) and the other two vertices being connected to the chassis (11) of the vehicle. 3. Train according to claim 2, characterized in that each half-train (1) comprises a damper (14) and a suspension spring (15), the free ends of the spring (15) being supported respectively against the body of the vehicle and the lower arm (4), the ends of the shock absorber (14) being connected in an articulated manner respectively to the vehicle body and to the lower arm (4). 4. Train according to any one of claims 1 to 3, characterized in that each half-train (1) comprises a third arm (16) disposed transversely to the longitudinal direction of the vehicle and forming a clamp rod whose ends are connected in an articulated manner respectively to the chassis (11) of the vehicle and to the wheel pivot (3) to allow the sketch of parallelism of the corresponding wheel (2) to be produced during the deflections of the latter. 5. Train according to claim 4, characterized in that the clamp link (16) of each half-train (1) is positioned in front of the axis of rotation of the wheel relative to the direction of movement in forward motion of the vehicle, and in that the distance separating the articulated connection (18) between the corresponding end of the clamp link (16) and the wheel pivot (3) and the axis of rotation of the corresponding wheel (2) is between sixty and one hundred and fifty mm. 6. Train according to any one of claims 1 to 5, characterized in that each half-train (1) comprises a fourth arm (19) of generally triangular shape intended to limit the travel of the corresponding wheel and disposed longitudinally to the vehicle , a top of the longitudinal arm (19) being connected to the chassis (11) of the vehicle and the two 5 ends opposite the apex being connected to the wheel pivot (3). 7. Train according to any one of claims 4 to 6, characterized in that each half-train (1) comprises an actuator in the form of a rack (22), one end of which is integral with the chassis (11) of the vehicle and the other end is hingedly connected to one end of the clamp link (16), the other end of the clamp link 10 (16) being hingedly connected to the wheel pivot (3), the actuator (16) being capable of transversely moving the clamp link (16) so that the corresponding wheel has a rotational movement around the turning axis (12). 8. Train according to claim 7, characterized in that the wheel turning angle of each half-train (1) is between zero and five degrees. 15 9. Train according to any one of claims 1 to 8, characterized in that each half-train (1) comprises a transverse transmission (23) intended to drive the corresponding wheel (2). 10. Motor vehicle comprising a rear axle according to any one of claims 1 to 9. 1/3 ο CN 2/3 3/3 ο ω