Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G17/00—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load
  • B60G17/015—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements
  • B60G17/017—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements characterised by their use when the vehicle is stationary, e.g. during loading, engine start-up or switch-off
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G17/00—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load
  • B60G17/015—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements
  • B60G17/0195—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements characterised by the regulation being combined with other vehicle control systems
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W10/00—Conjoint control of vehicle sub-units of different type or different function
  • B60W10/18—Conjoint control of vehicle sub-units of different type or different function including control of braking systems
  • B60W10/182—Conjoint control of vehicle sub-units of different type or different function including control of braking systems including control of parking brakes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W10/00—Conjoint control of vehicle sub-units of different type or different function
  • B60W10/22—Conjoint control of vehicle sub-units of different type or different function including control of suspension systems
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G2300/00—Indexing codes relating to the type of vehicle
  • B60G2300/38—Low or lowerable bed vehicles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G2400/00—Indexing codes relating to detected, measured or calculated conditions or factors
  • B60G2400/40—Steering conditions
  • B60G2400/41—Steering angle
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G2500/00—Indexing codes relating to the regulated action or device
  • B60G2500/30—Height or ground clearance
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G2800/00—Indexing codes relating to the type of movement or to the condition of the vehicle and to the end result to be achieved by the control action
  • B60G2800/20—Stationary vehicle
  • B60G2800/203—Stationary vehicle lowering the floor for loading/unloading

Definitions

• TITLE IMPROVED PROCESS FOR LOWERING A POSITIONED VEHICLE CHASSIS
• the invention relates to the field of vehicles whose chassis can be controlled so as to be able to be moved between a high rolling position and a low position for supporting this chassis on the ground.
• the invention preferably relates to delivery vehicles having a space for loading goods, and even more preferably to urban delivery trucks.
• the lowerability of the chassis makes it easier to load and unload goods. Indeed, when the chassis adopts its low position of support on the ground, the cargo space is located as close to the ground as possible.
• Such a vehicle comprises several wheels, and, associated with each wheel, a pivoting wheel suspension arm on the chassis. There is also provided, associated with each wheel, a suspension arm actuator arranged between the suspension arm and the frame. The actuator makes it possible to control an angular position of the arm relative to the frame, in order to vary the vertical position of this frame.
• the kinematics of the suspension arms are not necessarily the same at the level of each of these two running gear. Furthermore, it is generally recommended to carry out this lowering with the parking brake activated for each of the wheels of the vehicle, so as to avoid parasitic movement of the latter, in particular when the vehicle is parked on a sloping road.
• the invention relates to a method of lowering a vehicle chassis to a controlled vertical position, the vehicle being designed so that its chassis can be moved between a high position of rolling and a low position of support of this frame on the ground, the vehicle also comprising a plurality of wheels, and, associated with each wheel:
• a suspension arm actuator arranged between the suspension arm and the chassis, the actuator making it possible to control an angular position of the arm relative to the chassis, in order to vary the vertical position of this chassis, the vehicle comprising only two trains running gear, namely a front running gear and a rear running gear, each wheel of the running gear being associated with a parking brake, the method comprising the following successive steps:
• This method specific to the present invention makes it possible to lower the chassis to its lower position of support on the ground, without generating any stress in the running gear, thanks to the sequenced management of the parking brake on the wheels.
• the lowering of the chassis can thus be carried out without constraint, regardless of the kinematics associated with each of the suspension arms, and this with the guarantee that the vehicle remains stationary thanks to the parking brake applied to the wheels of one. of the two running gears during this lowering.
• the invention preferably provides at least one of the following optional characteristics, taken individually or in combination.
• the method comprises a step of detecting a steering angle of the wheels of the front running gear, and said step of lowering the chassis is carried out only if the detected steering angle is less than or equal to a value. safe.
• a step of safely loading the tires is implemented.
• said one of the two running gears corresponds to the rear running gear.
• it could be the front running gear, without departing from the scope of the invention.
• there is associated with each wheel a safety device capable of limiting the accidental lowering of the chassis, the device being able to adopt on the one hand an active state in which it makes it possible to limit the rotation of the suspension arm, in a first direction.
• the method comprises, before the step of lowering the frame, a step of switching the security devices from the active state to the inactive state.
• each wheel there is associated with each wheel a device for blocking the rotation of its suspension arm, and the method comprises, after the step of lowering the frame, a step for activating the devices for blocking the rotation arms of the suspension arms.
• suspension (28) associated with each of the wheels of the vehicle.
• each safety device comprises a jack of which a cylinder is mounted on the frame and of which a piston is mounted on the suspension arm, or vice versa, the jack defining a first chamber communicating with a first and a second passage for fluid through the cylinder, spaced from each other in a direction of sliding of the piston in the cylinder so that the second passage is located closest to a bottom of the first chamber defined by the cylinder, the second passage communicating with a first fluid line fitted with a safety valve adopting:
• FIG. 1 shows a schematic side view of a vehicle, with its frame in the high rolling position
• FIG. 2 shows a view similar to the previous one, with the frame in the lower position for resting on the ground;
• FIG. 3 is a bottom view of the vehicle shown in Figures 1 and 2;
• FIG. 4 shows a more detailed side view of part of the vehicle according to a first preferred embodiment, with the frame in the high rolling position;
• FIG. 5 shows a safety device to avoid the risks of accidental lowering of the frame to the ground, the safety device being associated with the wheel shown in FIG. 4, and shown in an active state as adopted with the frame in the high position of FIG. 4;
• FIG. 6 shows a view similar to that of Figure 4, with the wheel suspension arm in a safety position
• FIG. 6 ' shows a schematic side view of the vehicle, in the event of failure of the actuator associated with one of the rear wheels of this vehicle;
• FIG. 7 shows a view similar to that of FIG. 5, with the safety device shown in an active state as adopted when the suspension arm occupies its safety position of FIG. 6;
• FIG. 8 shows a view similar to that of Figure 6, with the frame in its lower position for bearing on the ground;
• FIG. 9 shows a view similar to that of Figure 7, with the security device shown in an inactive state as adopted when the frame occupies its lower support position of Figure 8
• FIG. 10 shows a view similar to that of Figure 4, with the vehicle being according to a second preferred embodiment
• FIG. 11 represents the safety device associated with the wheel shown in FIG. 10, and represented in an active state as adopted with the chassis in the high rolling position of FIG. 10;
• FIG. 12 shows a schematic view of another embodiment in which the safety devices, associated with the wheels of the vehicle, cooperate together to provide an anti-roll function
• FIG. 13 is a schematic view similar to that of FIG. 12, with the safety devices also integrating the function of shock absorber;
• FIG. 14 shows a view similar to that of FIG. 4, with the safety device and the actuator integrated within the same assembly, the latter also being able to integrate the damper;
• FIG. 15 shows a perspective view of one of the wheels of the vehicle, according to an improved embodiment
• FIG. 16 represents a view similar to that of FIG. 5, with the safety device incorporating an additional function of locking the wheel suspension arm in rotation;
• FIG. 16a is a view similar to that of FIG. 16, with the security device taking the form of an alternative;
• FIG. 17 shows the vehicle with its frame in the low position of support on a curved ground
• FIG. 18 represents a view similar to that of FIG. 12, with the safety devices incorporating an additional function of locking the wheel suspension arm in rotation;
• FIG. 19 is a schematic side view of the vehicle, with its frame in the high rolling position.
• FIG. 20 is a schematic view showing different steps of a method of lowering the frame shown in the preceding figures, the method being in the form of a preferred embodiment of the invention.
• Vehicle 1 of the type comprising a chassis 2 in a controlled vertical position.
• Vehicle 1 here preferably a truck urban delivery, in fact comprises a frame 2 which can be raised in a high rolling position as shown in Figure 1, and lowered in a low position for bearing on the ground 4, as shown in Figure 2.
• It may nevertheless be other types of vehicles, preferably road transport vehicles.
• the frame 2 also called a “box”, carries or delimits a loading space 6 for the goods.
• this space 6 is delimited downwards by the frame 2, so as to be as close to the ground as possible in the lower support position of the frame.
• this ground clearance G1 of the chassis 2 remains moderate, so as to limit the vertical travel required to reach the low position of support on the ground, adopted for unloading the goods.
• this ground clearance G1 is less than 500 mm, and preferably between 150 and 500 mm.
• the vehicle 1 comprises only two running gears, namely a front running gear 8, and a rear running gear 10.
• Each of the two trains is equipped only with two wheels in simple assembly, each of these wheels being individually articulated on the chassis 2 by a suspension arm, as will be described below.
• the design can be more complex. Indeed, it can for example be provided a front axle where the two wheels are on the same axle, itself articulated by “pushed” or “pulled” suspension arms, generally two in number per wheel and mounted in up and down the axle to create parallelogram kinematics.
• each of the wheels can be individually, or in pairs, articulated on the frame 2 by at least one suspension arm in “pushed” or “pulled” configuration.
• the front axle 8 thus comprises a left front wheel RI and a right front wheel R2, while the rear axle 10 comprises a left rear wheel R3 and a right rear wheel R4.
• the loading space 6 has a large area of rear overhang. In practice, this leads to observe, in view from below as shown in FIG. 3, that the vertical projection of the center of gravity 12 of the loaded vehicle is located at the rear of a crossing 14 between the two diagonals connecting the centers 16 of the treads 20 of the front and rear wheels R1-R4. In other words, the center of gravity 12 of the loaded vehicle is located behind with respect to a center of the wheelbase between the two running gears 8, 10.
• loaded vehicle it is here understood that its loading space 6 is entirely occupied by goods all having the same basis weight.
• the longitudinal distance of the center of gravity 12, relative to the middle of the wheelbase corresponding to the crossing 14 between the diagonals, can be of the order of 50 cm to 1 m, and extend up to 2 m.
• the vehicle 1 has a longitudinal direction referenced "L” in the figures, as well as a transverse direction referenced “T”.
• Figure 4 there is shown an assembly between one of the wheels of the vehicle, and the chassis 2.
• the left rear wheel R3 it is understood that the assembly is identical or similar for each of the four R1-R4 wheels. Also, only the assembly of the wheel R3 will be described below.
• the wheel R3 comprises a rim 22, as well as a tire 24 arranged around the rim. It is the tire 24 which defines the tread 20.
• the rim 22 is articulated along a wheel axis of rotation 26 on a suspension arm 28, of generally rectangular shape. The articulation of the wheel R3 takes place at one of the vertices of the arm 28.
• the latter is pivotally mounted at the level of another of its vertices on the frame 2, along an axis of rotation of the arm 30 parallel. or substantially parallel to the axis of rotation of the wheel 26.
• an actuator 32 of the suspension arm is articulated. This articulation takes place along an axis of rotation of the actuator 34, parallel to the axes 26, 30.
• the actuator 32 is supported on the frame 2, or also articulated on the latter. This actuator 32 makes it possible to control the angular position of the suspension arm 28 relative to the frame 2, in order to vary the vertical position of this frame as desired.
• the actuator 32 is here of the air cushion type. It is the control of its internal pressure which makes it possible to adjust its longitudinal extent between the arm 28 and the frame 2, which extent determines the angular position of this arm 28. This pressure is regulated by a control unit 33 of the vehicle, unit which may be common to all four wheels, while being able to deliver different control signals depending on the wheels.
• the angular position of the suspension arm 28 is such that it forms an angle A1 relative to the frame 2, this angle A1 being determined in side view between the normal to the frame or the vertical, and a fictitious line connecting the two axes 26, 30.
• the angle A1 adopted while the vehicle is running is for example of the order of 90 °, but it can obviously be lower or higher.
• the suspension arm 28 being preferably damped, the value of the angle Al varies during the damping phases encountered during travel.
• a damper 36 is provided, of any design known to those skilled in the art. The opposite ends of the shock absorber 36 are articulated on the arm 28 and the frame 2, along axes also parallel to the axes 26, 30, 34.
• This safety device is capable of limiting the accidental lowering of the frame 2 on the ground 4, by adopting an active state in which it limits the rotation of the frame. suspension arm around the axis 30, according to a first direction of rotation SI corresponding to the clockwise direction in FIG. 4. It is indeed in this direction of rotation that the arm 28 leads to the lowering of the frame 2 in the direction of the ground 4.
• the safety device 40 shown only diagrammatically in FIG. 4, is also articulated at its two opposite ends on the frame 2 and on the suspension arm 28, along axes of rotation 42, 44 parallel to the axes 26, 30, 34.
• the security device 40 is distinct from the damper 36, but these two items of equipment can advantageously be merged, as will be described later.
• the safety device 40 in more detail, still in its active state preventing the accidental lowering of the frame to the ground. It comprises a hydraulic cylinder 46, a cylinder 48 of which is mounted articulated on the suspension arm 28 along the axis of rotation 42, and of which a piston 50 is mounted articulated on the frame 2 along the axis 44, or vice versa.
• the piston head 52 defines on either side thereof a first oil chamber 54, and a second oil chamber 56.
• the first chamber 54 is also defined by a first chamber bottom 58
• the second chamber 56 is also defined by a second chamber bottom 60 through which the piston rod 50 passes.
• the first chamber 54 communicates with a first oil passage 62 made laterally through the cylinder 48. It also communicates with a second oil passage 64 made through the cylinder 48, this second passage being close to the bottom of the first chamber. 58, and in any event closer to this bottom 58 than the first passage 62 is.
• the two passages 62, 64 are in fact spaced from one another in a sliding direction 66 of the piston. in the cylinder.
• the second passage 64 communicates with a first oil line 68, while the first passage 62 communicates with a second oil line 70 connected to the end of the first line 68. Upstream of this connection, the first line 68 is equipped with a safety valve 72, this valve being able to be manual, but preferably being a solenoid valve controlled by the control unit 33.
• the second chamber 56 communicates with a third oil passage 74 produced laterally through the cylinder 48, this third passage preferably being arranged near the bottom of the second chamber 60.
• the third passage 74 communicates with the end a third oil line 76, belonging to a fluid circuit 78, which will be described below.
• the first fluid line communicates not only with the second line 70 connected to the first passage 62. , but also with the other end of the third oil pipe 76 belonging to the fluidic circuit 78.
• the latter is completed by a tap on the third pipe 76, between its two ends, a tap which leads to an oil tank 80 leaving in its upper part an air reserve 82.
• the valve 72 In the active state of the security device 40 as shown in FIG. 5, the valve 72 is maintained in the closed position. In this state, the oil cannot pass through the second passage 64, due to the closing of the valve 72. On the other hand, the oil can freely circulate between the two chambers 54, 56 via the first orifice 62, the second pipe 70, the third pipe 76, and the third passage 74. Consequently, the piston 50 can accompany the movements of the damper during travel, by moving its piston head 52 between the first and third passages 62, 74 Above all, in this active state of the safety device 40, the piston 50 is capable of stopping its travel in the direction 66 to avoid too great a lowering of the chassis, and thus to avoid its unwanted impact on the ground during travel.
• the weight of the frame 2 and the load of the vehicle cause a rotation of the suspension arm 28 along the axis 30 in the first direction SI, shown diagrammatically by the arrow in Figure 6.
• the unwanted rotation of the suspension arm 28 causes a displacement of the piston head 52 in the direction of the bottom 58, expelling the oil from the first chamber 54 via the first passage 62, in the direction of the second chamber 56 via lines 70, 76 and the third passage 74.
• This locking of the piston 50 in the safety position advantageously causes the stopping of the accidental rotation of the suspension arm 28 relative to the frame 2, in the SI direction.
• This arm 28 then remains maintained in its safety position shown in FIG. 6, which locally provides a non-zero ground clearance G2 in order to avoid accidental contact with the ground.
• the latter forms an angle A2 with the normal to the frame 2, this angle A2 obviously being less than the angle A1 described previously with reference to FIG. 4.
• G2 can for example be increased by 10, 40 or 60%, and this increase is thus taken into account in the design of the safety devices associated with the wheels.
• a similar reasoning is carried out to avoid the risks of contact of the cantilevered front part of the vehicle, with the ground, during a failure of an actuator associated with a front wheel.
• the security device 40 can alternatively adopt an inactive state as shown in FIGS. 8 and 9, in which the valve 72 is in the open position.
• this state adopted to voluntarily lower the frame 2 to the ground the oil can be extracted from the first chamber 54 even after the passage of the piston head through the first passage 62, via the second passage 64 located near the bottom 58. This allows an additional stroke of the piston 50 beyond the first passage 62, to accompany an additional rotation of the arm 28 making it possible to bring the frame 2 to the ground 4.
• the arm 28 When the frame 2 reaches the ground, the arm 28 is in an angular position such that it forms an angle A3 with the normal to the frame 2, this angle A3 shown in FIG. 8 being obviously less than the angle A2 described previously. with reference to figure 6.
• FIG. 10 there is shown a second preferred embodiment in which the security device 40 is integrated into the damper 36, or vice versa.
• a single assembly fulfills the two functions of safety and damping, this assembly being articulated at its ends at two points respectively on the suspension arm 28 and the frame 2, along the axes 42, 44.
• the shock absorber cylinder is formed by the cylinder 46 of the safety device 40, or vice versa.
• the second embodiment has the same characteristics as those of the first embodiment, to which are added equipment within the fluidic circuit 78.
• the third pipe 76 of this circuit is in fact equipped with a loop 84 arranged between the tapping of the reservoir 80. , and its connection to the third passage 74.
• This loop 84 incorporates elements to fulfill the function of a damper. To this end, it incorporates within a main duct 90a a first non-return valve 86a, associated with an orifice for passage of fluid in compression 88a. The loop also includes a pipe 90b for bypassing the orifice for the passage of fluid in compression 88a, this pipe 90b being equipped with a second non-return valve 86b associated with an orifice for the passage of fluid in expansion 88b.
• the second check valve 86b allows oil to flow in a direction opposite to that of the first check valve 86a. Consequently, during the damping phase, the oil passes through the main duct 90a, while during the rebound phase, the oil passes through the bypass duct 90b.
• the oil passes through the compression fluid passage orifice 88a, which is calibrated so as to ensure energy dissipation and damping by rolling the oil.
• the damping is determined by the passage of oil through the other passage orifice 88b. Consequently, by providing that the two orifices 88a, 88b have different passage sections, it is advantageously obtained a differentiated damping in compression and in rebound.
• the safety devices 40 of the different wheels of the vehicle can cooperate in pairs to provide an anti-roll function.
• Fig. 12 shows the cooperation of the devices 40 for the two wheels R3, R4 of the rear running gear, but the same or similar cooperation can be adopted for the two wheels of the front running gear.
• the end of the third pipe 76 of the safety device 40 associated with the left rear wheel R3 no longer communicates with the third passage 74 of the cylinder 46 of this device 40, but it communicates with the third passage 74 of the cylinder 46 belonging to to the safety device 40 associated with the right rear wheel R4, transversely opposite to the left rear wheel R3. Consequently, when the piston 50 of the right rear wheel R4 descends into its cylinder 48 following a rotation of the suspension arm of this wheel R4, the oil from the first chamber of the cylinder 54 associated with the wheel R4 is expelled in the direction of the second chamber 56 of the jack associated with the other wheel R3.
• the safety devices 40 also integrate the function of a shock absorber, as has been shown in FIG. 13.
• the actuator 32 in the form of an air cushion is integrated into an assembly incorporating the safety device 40, with the latter also being able to incorporate the damping function in the sense described with reference to FIGS. 10 and 11.
• the longitudinal axis 92 of the air cushion coincides with an axis of the cylinder 46 of the safety device 40.
• a longitudinal end of the air cushion 32 is integral with the cylinder 48, while its longitudinal end opposite is mounted to pivot on the frame 2, along the axis of rotation 44.
• the piston 50 has its rod pivotally mounted on the suspension arm 28, along the axis of rotation 42.
• This wheel R3 comprises, in addition to the rim 22 and the tire 24 defining the tread 20, a reinforcement 96 arranged radially around the rim.
• the reinforcement 96 is intended to be contacted by an inner part of the tread 20 of the tire, in the event of a loss of pressure, thus avoiding direct contact between the tire 24 and the rim 22. It is designed rigid so as not to sag. 'sag under the weight of the vehicle, thus helping to avoid the risk of accidental lowering of the chassis to the ground, in the event of loss of tire pressure, for example following a puncture.
• the ground clearance G2 provided locally at the level of the wheel by its safety device is preferably greater than the maximum amplitude of the wheel sag, following a loss of pressure in its tire which may result from deflation or of a burst.
• the principles set out above with reference to FIG. 6 ′ are also applicable to a situation of cumulative failure of an actuator associated with one of the wheels, and a loss of pressure in this wheel leading to rolling on the reinforcement 96.
• each wheel is associated with a device for locking the wheel suspension arm in rotation, this locking device being here integrated into the safety device 40.
• a shut-off valve 98 preferably a solenoid valve controlled by the control unit.
• a manually operated shut-off valve can also be envisaged, without departing from the scope of the invention.
• the stop valve 98 is arranged within the fluid circuit 78, on the third pipe 76 near the connection with the first and second pipes 68, 70.
• shut-off valves 98 preferably fitted to the safety device 40 of each of the wheels, such risks are avoided for people located near the vehicle.
• the shut-off valve 98 may be arranged at another location on the third line 76, for example near the third oil passage 74 through the cylinder 48, as has been shown in Fig. 16a.
• this principle of implantation of the stop valve 98 for locking the suspension arm in rotation also applies to cases where the safety device 40 integrates the shock absorber function described with reference to FIG. 11.
• the stop valve 98 can be installed upstream or downstream of the loop 84, without departing from the scope of the invention.
• the safety device associated with each wheel integrates several of the additional functions described above, or even all of them, namely the shock absorber function, the function. anti-roll, the actuator integration function, and the function of locking the suspension arm in rotation by locking the piston in translation.
• the safety device presented above remains optional, and in addition, when such a safety device is provided. for one or more wheels of the vehicle, its design may be different from that shown in the various modes described above.
• the safety device does not necessarily integrate a jack.
• Other preferred characteristics will be described below, and they can of course be combined with those described above.
• the vehicle 1 is shown in the running configuration, that is to say with its frame 2 in the high running position defining the ground clearance G1.
• the particularity of the vehicle lies in the fact that the kinematics associated with each of the four wheels are identical. More precisely, these identical kinematics make it possible to generate an identical or substantially identical longitudinal offset of the frame 2 with respect to the ground 4, when this frame is lowered. Thanks to this design, the lowering of the chassis to its lower position of support on the ground does not generate any stress in the running gear 8, 10, even when all the wheels are blocked by a parking brake during this lowering. .
• the suspension arm 28 has an arm length "LB" defined between the two axes of rotation 26, 30;
• the axis of rotation of the arm 30 has a first vertical distance to the ground "DV1";
• the wheel axis of rotation 26 has a second vertical distance to the ground "DV2" less than the first;
• the wheel comprises a tread 20 having a wheel diameter "D".
• the axis of rotation of the arm 30 is offset longitudinally from the axis of rotation of the wheel 26 in the same direction, here towards the rear leading to a configuration with "pushed” arm, even if a reverse configuration with "pulled” arm Is also conceivable, without departing from the scope of the invention;
• the arm length LB is the same or substantially the same
• the first vertical distance on the ground DV1 is the same or more or less the same;
• the second vertical distance to the ground DV2 is the same or more or less the same.
• the wheel diameter D is the same or more or less the same.
• the tolerated deviations are such that when they are combined, the difference in longitudinal offset induced on the chassis between the smallest offset among the four wheels, and the highest offset, n 'not exceed 5 cm, or even 2 or 3 cm.
• This small offset deviation can in fact be absorbed by moderate sliding of the tires on the ground during lowering, without causing harmful stresses on the running gear, even with all four wheels blocked by the parking brake.
• the invention proposes a method for lowering the chassis, applicable to all of the vehicles described above.
• FIG. 20 shows diagrammatically the different steps of such a method for lowering the chassis 2 of the vehicle, particularly suitable when all the wheels do not have the same kinematics of movement during the lowering, unlike the mode described with reference to FIG. 19.
• the method is also applicable in this mode, without departing from the scope of the invention.
• the method begins with a step E1 of waiting for receipt of an order to lower the frame.
• This order can be triggered by an operator, for example via a dedicated button on the dashboard, or any other button connected to the control unit 33 of the vehicle.
• step E2 consists in checking that the wheels of the front axle do not have a steering angle that is too high, because otherwise this could lead to the vehicle being rotated during lowering of the chassis. Thus, if the steering angle is greater than a safe value, a step E'2 is implemented to restore the steering until a suitable steering angle is obtained.
• This step E'2 can be carried out automatically using a motorized steering system, or else manually by the operator, by acting directly on the steering wheel of the vehicle.
• step E3 can be implemented, consisting of actuating the parking brake only for the wheels R3, R4 of the rear running gear.
• the parking brake is not illustrated, but that it adopts any conventional form known to those skilled in the art.
• step E4 resides in the tilting of all the safety valves 72 from their closed position to their open position, so as to place them. security devices 40 in the inactive state.
• Step E5 then consists of lowering the frame 2, by controlling the actuators 32, again via the unit 33 of the vehicle. Moreover, this unit 33 can be programmed to successively implement all of the steps of this method, automatically, that is to say without operator intervention.
• the lowering step E5 is continued until the frame 2 rests on the ground 4, in its lower support position.
• a step E6 can be carried out for the safe loading of the tires of the wheels.
• This optional step aims to ensure that the tires are not completely unloaded following the support of the chassis on the ground. It is for example implemented by operating a command for lifting the frame 2 via the actuators 32, so as to cause a small vertical relative displacement between this frame and the axis of rotation of each wheel. This vertical displacement does not normally exceed more than a few millimeters, in order to avoid a loss of contact between the chassis 2 and the ground 4.
• loading the tires on the ground strengthens the overall grip of the vehicle in position. bass sound support frame. The risks of the vehicle slipping are thereby reduced, which remains particularly advantageous when the vehicle is lowered on sloping ground.
• step E7 can be implemented, consisting in actuating the parking brake for the wheels RI, R2 of the front running gear, with the parking brake kept activated for the wheels of the rear axle. .
• step E8 lies in the activation of the devices 98 for blocking the rotation of the arms 28 of the wheel suspension, in order to avoid the risk of parasitic movements of the chassis during unloading / loading of goods.
• step E7 for actuating the parking brake for the wheels RI, R2 of the front running gear could be carried out after step E8 for activating the devices 98 for blocking the rotation of the arms 28 of the wheels. , without departing from the scope of the invention.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Automation & Control Theory (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Transportation (AREA)
• Vehicle Body Suspensions (AREA)
• Regulating Braking Force (AREA)

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• 2020
  • 2020-01-08 FR FR2000125A patent/FR3105955B1/fr active Active
• 2021
  • 2021-01-05 JP JP2022542017A patent/JP7673072B2/ja active Active
  • 2021-01-05 US US17/791,394 patent/US12005754B2/en active Active
  • 2021-01-05 WO PCT/FR2021/050006 patent/WO2021140293A1/fr not_active Ceased
  • 2021-01-05 EP EP21705234.9A patent/EP4087744A1/de active Pending

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