FR2935300A1 - Wheel i.e. rear wheel, trajectory active guiding device for vehicle, has actuator arranged between wheel support and vehicle body shell, and adjustable connecting rod displaced by actuator that includes locking device to block rod - Google Patents

Abstract

The device has an actuator comprising a hydraulic or pneumatic adjustment unit (4) and arranged between a wheel support (5) that supports a wheel (9) i.e. rear wheel, of a vehicle, and a vehicle body shell (2). An adjustable connecting rod (10) is displaced by the actuator. The actuator includes a locking device to block the connecting rod. The actuator is arranged on a rear axle of the vehicle for active guiding of the rear wheel of the vehicle.

Description

The present invention relates to a device for actively guiding the trajectory of the wheels of a vehicle. The guidance of the trajectory of a wheel is carried out by a coupling rod connected to a steering or by an elasto-axial rod / lever adjustment of the axle system or by a combination of these two devices or processes. It is also known to equip in particular the rear axles of vehicles with active guidance devices of the trajectory. Such active guidance of the trajectory has been used in series since the end of the 1980s. However, the old systems were not coupled to an electronic control of the driving dynamics, because such electronic systems did not exist at that time. . According to the most recent state of the art, active guidance devices are used for the trajectory of the wheels of the vehicles, in which the trajectory guidance device is replaced by an actuator. Such an actuator may also be arranged in the center and be connected on both sides, via a connecting member, with the path guidance devices. Said actuator then sets the trajectory of the wheels on this axle according to the driving situations of the vehicle.

The disadvantage of these actuators, able to be controlled or adjusted electronically, is the fact that these, even for positioning the wheels in a neutral position, in which the wheels are positioned in a straight path, must be powered by energy to maintain the neutral position.

In addition, the continuous power supply of the actuators, even in the neutral position, leads to greater fuel consumption and a greater clearance of the vehicle. The object of the present invention is to design a device for actively guiding the trajectory of the wheels of a vehicle, which overcomes the aforementioned drawbacks. This objective is solved by an active guide device of the wheel trajectory of a vehicle comprising at least one actuator, which is arranged between a wheel support, carrying a wheel of the vehicle, and a vehicle body, and a connecting rod of setting, which can be moved by the actuator.

Advantageous embodiments of the invention may include the following features taken individually or in combination: the actuator is provided on a rear axle of a vehicle for actively guiding the trajectory of the rear wheels of the vehicle.

the actuator is designed as a control unit that can be actuated hydraulically or actuated pneumatically.

The adjustment unit comprises a) a casing, b) a regulating piston, in active connection with the adjusting rod engaging inside the casing, and c) at least one energy reservoir, 15 said adjusting rod and said adjusting piston (being movable axially with respect to an axle connecting the wheel support and the vehicle body.

- The clamping device comprises a first clamping cone, 20 disposed against the inner face of the housing, and a second clamping cone, disposed against the adjusting rod.

the second clamping cone can slide on the first cone

said at least one energy reservoir is a reservoir of energy

the energy reservoir is in the form of a pressure spring.

the adjusting piston and the adjusting rod can be positioned by the energy reservoir so that the second clamping cone, arranged against the adjusting rod, is engaged with the first clamping cone, arranged against the inner face of the housing, and thereby locks the adjustment rod. Clamping. 25

mechanical. the adjustment unit can be actuated electrically by a pressure generating unit and a control unit. - The control unit can be switched on or off electrically via the control unit.

the actuator is disposed between the wheel support, carrying the vehicle wheel, and an axle support of the vehicle body. - The energy reservoir is disposed between the adjusting piston and an inner wall of the housing, remote from the vehicle wheel and located opposite the adjusting piston in the direction of movement of the adjusting piston.

The adjusting piston and the adjustment rod can be positioned by the energy reservoir so that the second clamping cone, arranged against the adjusting rod, is engaged with the first clamping cone, arranged against the inner face of the housing, and thus blocks the adjustment rod. The adjusting piston and the adjusting rod can be positioned by the energy reservoir so that the second clamping cone, arranged against the adjusting rod, is engaged with the first clamping cone, arranged against the inner face of the housing, and thereby blocks the adjustment rod in a predefined return position.

the preset return position of the adjustment unit induces a right-angle orientation of the wheels on the axle provided with the adjustment unit. the actuator comprises a partition between the adjusting piston and the clamping device. the energy reservoir is disposed between the partition and the clamping cone located closest to said partition. The clamping device can be positioned by the energy reservoir in such a way that the second clamping cone, arranged against the adjusting rod, is engaged with the first clamping cone, arranged against the inner face of the housing, and thereby blocks the adjustment rod.

Thanks to the design of the actuators with a clamping device for locking the adjustment rod, the invention realizes an active guidance of the simple and safe trajectory which, even in case of failure of the adjustment unit, allows a behavior of safe and controlled driving of the vehicle. In addition, by blocking the adjustment rod, it is possible to inject energy into the actuator only during active service thereof. In the rest position or deactivated position, said actuator does not consume energy and, as a result, reduces the fuel consumption of the vehicle. Preferably, the adjustment unit comprises a casing, a regulating piston in active connection with the control rod engaging inside the casing, and at least one energy reservoir, the adjusting rod and the piston. adjustment being axially movable relative to an axle connecting the wheel support and the vehicle body. By the use of an energy reservoir, in particular in the form of a pressure spring, it is ensured that, even in the event of failure of the control unit, the energy required for the blockage of the Tuning link is available. In a preferred embodiment, a partition is arranged between the adjusting piston and the clamping device. In this case, the energy reservoir is arranged between the partition and the clamping cone closest to the partition, so that the clamping device can be positioned by the energy reservoir so that the second clamping cone, arranged on the adjusting rod, engages with the first clamping cone arranged against the inner face of the housing and blocks in this case the adjustment rod. As a result, the adjustment linkage, upon voluntary deactivation of the actuator, can be adjusted first of all so that the wheels of the vehicle are oriented for a straight path and are subsequently locked so that, during the entire duration of driving in a straight line, no energy is required for the operation of the actuator. According to a particular variant, the adjustment unit comprises an energy reservoir in active connection with the adjusting piston, said energy reservoir being prestressed by the axial movement of the adjusting piston. In this case, the adjustment unit can be immobilized in a neutral position under the effect of the force of the energy reservoir, so that the adjustment unit behaves in this immobilized position as a conventional device of trajectory guidance. The principle of such a control unit is known from EP 1 448 900 B1. In said document, it is a hydraulic cylinder with automatic locking in case of pressure drop. A cone on the piston rod of the hydraulic cylinder is moved by a spring on a cone in the opposite direction, arranged against the wall of the cylinder, whereby the piston rod is blocked. Said hydraulic cylinder has been developed in particular for injection molding machines and presses. In this sector of the art, such a blocking function is essential to not endanger the health of the user of such a control unit in the presence of a pressure drop. An application of such a cylinder in the field of automotive technology has not been made yet.

The adjustment unit is preferably provided with an energy reservoir in the form of a pressure spring. In this embodiment, it is possible, by the choice of the spring constant, to determine the neutral position of the adjustment unit, in particular of the piston rod of the adjustment unit.

The clamping device of the adjusting unit is preferably in the form of a first and a second clamping cone, which are arranged against the inner face of a housing of the unit. and the other against the control rod of the control unit. Because the two cones are engaged with each other in the neutral position, the diameter of the first clamping cone is decreased, so that it is supported on the side face of the control rod . Thus, the adjustment rod is blocked in a simple and safe way and maintains this position without additional energy consumption. The engagement of the two cones in one another is obtained here only under the effect of the restoring force of the pressure spring. The invention is explained below in more detail with reference to exemplary embodiments with reference to the drawings, in which: FIG. 1 is an elevational view of an axle zone, represented diagrammatically, of a vehicle ; Figure 2 is a detailed enlargement showing elements of the device according to Figure 1, to explain the function of the invention; FIG. 3 is a detailed enlargement showing a variant embodiment of the elements of the device according to FIG. 1. In the following description of the figures, the terms, such as top, bottom, left, right, front, rear, etc., are refer only to the representation and the position, chosen as an example in the figures concerned, of the device and parts thereof. These terms should therefore not be understood in a limiting sense, that is to say that these concepts vary according to the different working positions or by a symmetrical design or the like. Figure 1 shows an embodiment of a device for actively guiding the trajectory of the wheels 9 of a vehicle. The wheels 9 of the vehicle (only one of which is shown in FIG. 1) are mounted on an axle, in particular a rear axle, which is fixed to the body 2 of the vehicle, in particular to an axle support. The wheel is fixed on a wheel support 5 by means of a connecting element 8. The assembly of the wheel support 5 with the body 2 of the vehicle is ensured, on the one hand, by means of an arm suspension 3 which, by means of connecting elements 6, 7, preferably silentblocs, is attached to the wheel support 5 and the body 2 of the vehicle. On the other hand, the second assembly between the body 2 of the vehicle and the wheel support 5 is formed by a control unit 4, which is also attached to the wheel support 5 and the body 2 of the vehicle via connecting elements 6, 7, preferably silentblocs. The details of the adjustment unit are shown diagrammatically in FIGS. 2 and 3. The control unit 4, shown in FIG. 2, preferably made in the form of a hydraulic or pneumatic adjustment unit 4, comprises a housing 11, preferably cylindrical, a control rod 10, a clamping device 14 for locking the adjusting rod 10, and an adjusting piston 13 in operative connection with the adjusting rod 10. A partition 20, parallel to the adjusting piston 13, separates the adjustment unit 4 into two zones. A clamping zone, in which the clamping device 14 is arranged, is situated on the drawing to the left of the partition 20. To the right of the partition 20 is located an adjustment zone, in which the piston of adjustment 13 connected to the adjustment rod 10.

Between the partition 20 and the clamping device 14 is arranged an energy reservoir 12, which pushes the clamping device 14 into a locking position for locking the adjusting rod 10. The adjusting rod 10 and the adjusting piston 13 are axially movable relative to an axle connecting the wheels 9 of the vehicle. The control rod 10 is connected at one end firmly to the adjusting piston 13, disposed in the housing 11, passes through an opening in the partition 20 and engages with its other end out of the housing 11 of the control unit 4. At the end of the adjustment rod 10, coming out of the housing 11, there is provided a connecting element 7, through which the adjusting rod 10 is fixed against the wheel support 5. On the on the inner side of the clamping zone, located in front of the partition 20 in the casing 11, is disposed a first clamping cone 15 which, in cooperation with a second clamping cone 16 arranged so as to slide on the adjustment rod 10, is able to lock the adjusting rod 10. The locking is obtained in this case by a fitting of the second clamping cone 16 on the first clamping cone 15, knowing that under the effect of the fitting, the inside diameter of the father The first clamping cone 15 is reduced and thereby the latter rests on the outer lateral surface of the adjusting rod 10 and blocks it by force. The force to press the second clamping cone 16 on the first clamping cone 15 is provided by an energy reservoir 12, more precisely two in the embodiment shown. Said energy reservoir 12 is preferably in the form of a pressure spring, in particular in the form of a helical spring. Furthermore, in the particular embodiment in the form of a hydraulic or pneumatic control unit, the housing 11 of the control unit 4 comprises three inputs / outputs 17, 18, 19, namely one in each of the three chambers of the housing 11 of the control unit 4, formed by the partition 20 and the adjusting piston 13, which inputs / outputs are intended for a fluid under pressure, in particular a hydraulic fluid or compressed air. The first inlet / outlet 17 serves in this case to release the clamping device 14, knowing that, under the effect of the introduction of a fluid under pressure via the first inlet / outlet 17, a totally uniform force is exerted on the clamping cone 16 and the latter pushes back the energy reservoir (s) 12. As a result, the clamping cone 16 is no longer engaged with the clamping cone 15, which confers a free Mobility to the adjustment rod 10. In the event of pressure being relieved of the pressure medium exerted on the clamping cone 16, the energy reservoir 12 pushes the clamping cone 16 onto the clamping cone 15 and from this The second input / output 18 and the third input / output 19 serve to position the adjusting piston 13 and thus the adjustment link 10. As a function of the distribution of the pressure on the two Inlets / outlets 18, 19, the fluid under pressure pushes the pisto n adjustment to the wheel support (to the left in the figure) or to the axle support (to the right in the figure). The inputs / outputs 17, 18, 19 are electrically actuated via a pressure generating unit (not shown). Said pressure generating unit controls, in the operating position, the release pressure for unlocking the adjusting rod via the clamping device 14, and the position of the adjusting piston 13 or the position of the adjustment rod 10 and therefore also the trajectory of the vehicle wheels 9 mounted on said axle of the vehicle. During operation, the control unit 4 is actuated by a control unit (not shown) and a pressure generating unit, connected thereto, which first analyzes all the vehicle data relating to the driving dynamics and safety (eg, speed, yaw rate, steering angle, wheel speeds) and calculates the optimum trajectory of the wheel 9. To vary the position of the wheel with a control unit 4 made in the form of a hydraulic adjustment unit 4, the adjusting link 10 must be released under the effect of the separation of the clamping device 14. Under the effect of the introduction of a hydraulic fluid via the inlet 18, the adjusting piston 13 is moved out of its neutral position. This triggers, via the adjusting rod 10, connected to the adjusting piston 13, a guide wheel 9 which is connected to the adjusting rod 10 via the wheel support 5. The recall of the wheel in the right trajectory position, namely the return of the adjustment unit 4 in the neutral position, occurs firstly via the inputs / outputs 18, 19. Once the neutral position is reached, the inlet / outlet 17 opens, so that the hydraulic pressure applied to the clamping device 14 is eliminated and that, therefore, only under the effect of the force applied by the pressure spring 12 on the second clamping cone, the adjusting rod 10 is locked in its neutral position. In the variant embodiment, shown in FIG. 3, for the actuator 4 or the adjustment unit 4, the interior of the casing of the actuator 4 is divided into two chambers by the adjustment piston 13, knowing that in the chamber facing the vehicle wheel 9 (the left chamber in Figure 2), the adjusting rod 10 is disposed perpendicularly on the adjusting piston 13 and engages out of the housing 11 to the wheel 9 of the vehicle. In this case, the adjusting piston is in active connection with the energy reservoir 12, said energy reservoir 12 being prestressed by the axial movement of the adjusting piston 13. The actuator 4 can be immobilized here in a position neutral by the force applied by the energy reservoir 12 on the adjusting piston 13, so that the actuator 4, in this immobilized position, behaves as a conventional path guidance device. During operation, said adjustment unit 4 is actuated via the control device (not shown) of the pressure generating unit. To vary the position of the wheel with a control unit 4 made in the form of a hydraulic adjustment unit 4, it is necessary to bring the adjustment piston 13 out of the neutral position under the effect of the introduction of a hydraulic fluid via the inlet 17. Thus, via the adjusting rod 10, connected to the adjusting piston 13, there is a guide wheel 9 which is connected to the adjustment rod 10 by the intermediate wheel support 5. The return of the wheel in the position in the right path, namely the return of the adjustment unit 4 in the neutral position, occurs under the effect of the opening of the two inputs / outputs 17, 18. As a result, the hydraulic pressure applied to the adjusting piston 13 is eliminated and the adjusting piston 13 is returned to its neutral position only under the influence of the pressure spring 12.

In the neutral position of the adjusting unit 4, the adjusting rod 10 is locked, as explained above, by the clamping device 14 in the adjusting unit 4. As a result, the unit 4 in its neutral position behaves like a conventional path guidance device. In this position, it is unnecessary to route energy from the outside to the control unit, since this position, more precisely the locking position of the adjusting rod 10, is maintained solely by the rigidity of the spring 12. If the right trajectory is relatively long, the adjustment unit 4 in a preferred embodiment can be manually deactivated via the control unit, for example by means of a manual operation of a control element. , disposed in the dashboard of the vehicle and electrically connected to the control unit, and subsequently said adjustment unit can be put into operation again. The adjustment unit is always brought automatically to its neutral position when, apart from the force of the energy reservoir 12, no other force is exerted on the adjusting piston 13, in particular any force generated by the hydraulic or pneumatic system. Thus, the adjustment unit 4 is brought into or remains in this neutral position even in the event of failure, for example, of the pressure generating unit intended to supply the hydraulic or pneumatic system of the control unit 4.

Claims (19)

REVENDICATIONS1. Active device for guiding the trajectory of the wheels (9) of a vehicle, comprising a) at least one actuator (4), which is arranged between a wheel support (5) carrying a wheel (9) of the vehicle, and a box (2) of the vehicle, and b) a control rod (10), displaceable by the actuator, characterized in that c) said at least one actuator (4) comprises a clamping device (14) for to lock the adjusting rod (10). 2. Device according to claim 1, characterized in that the actuator (4) is formed on a rear axle of a vehicle for the active guidance of the trajectory of the rear wheels (9) of the vehicle. 3. Device according to claim 1 or 2, characterized in that the actuator (4) is formed as a control unit (4) operable hydraulically or actuated pneumatically. 20 4. Device according to any one of claims 1 to 3, characterized in that the adjusting unit (4) comprises a) a housing (11), b) a control piston (13), in active connection with the adjusting rod (10) engaging inside the housing (11), and c) at least one energy reservoir (12), said adjusting rod (10) and said adjusting piston (13) being movable axially relative to an axle connecting the wheel support (5) and the body (2) of the vehicle. 30 5. Device according to claim 4, characterized in that the clamping device (14) comprises a first clamping cone (15), arranged against the inner face of the housing (11), and a second clamping cone (16), arranged against the adjustment rod (10). 35 6. Device according to claim 5, characterized in that the second clamping cone (16) is slidable on the first clamping cone (15). 7. Device according to claim 4 or 5, characterized in that said at least one energy reservoir (12) is a mechanical energy reservoir. 8. Device according to claim 6, characterized in that the energy reservoir (12) is in the form of a pressure spring (12). 10 9. Device according to one of claims 5 to 8, characterized in that the adjusting piston (13) and the adjusting rod (10) can be positioned by the energy reservoir (12) so that the second the clamping cone (16), which is arranged against the adjusting rod (10), is engaged with the first clamping cone (15), arranged against the inner face of the casing (11), and thereby blocks the adjusting link (10). 10. Device according to any one of the preceding claims, characterized in that the control unit (4) can be actuated electrically by a pressure generating unit and a control unit. Device according to claim 10, characterized in that the control unit (4) can be switched on or off electrically via the control unit. 12. Device according to any one of the preceding claims, characterized in that the actuator (4) is disposed between the wheel support (5), carrying the vehicle wheel (9), and an axle support of the 30 body (2) of the vehicle. 13. Device according to one of claims 4 to 12, characterized in that the energy reservoir (12) is disposed between the adjusting piston (13) and an inner wall of the casing (11), away from the 35 roue of vehicle and located in front of the adjusting piston (13) in the direction of movement of the adjusting piston (13). Device according to Claim 13, characterized in that the adjusting piston (13) and the adjusting rod (10) can be positioned by the energy reservoir (12) in such a way that the second clamping cone (16) ), arranged against the adjusting rod (10), is engaged with the first clamping cone (15), arranged against the inner face of the housing (11), and thereby blocks the adjustment rod (10). 15. Device according to claim 14, characterized in that the adjusting piston (13) and the adjusting rod (10) can be positioned by the energy reservoir (12) so that the second clamping cone (16) ), arranged against the adjusting rod (10), is engaged with the first clamping cone (15), arranged against the inner face of the housing (11), and thereby locks the adjusting rod (10) in a preset recall position. Device according to claim 15, characterized in that the predetermined return position of the adjusting unit (4) induces a right-hand orientation of the wheels (9) on the axle provided with the adjusting unit ( 4). 17. Device according to any one of claims 4 4 to 12, characterized in that the actuator (2) comprises a partition (20) between the adjusting piston (13) and the clamping device (14). 18. Device according to claim 17, characterized in that the energy reservoir (12) is disposed between the partition (20) and the clamping cone (15, 16) located closest to said partition. 30 19. Device according to claim 18 in combination with claims 4 and 5, characterized in that the clamping device (14) can be positioned by the energy reservoir (12) so that the second clamping cone (16) ), arranged against the adjusting rod (10), engages with the first clamping cone (15), arranged against the inner face of the housing (11), and thereby blocks the adjustment rod (10). 25