Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60P—VEHICLES ADAPTED FOR LOAD TRANSPORTATION OR TO TRANSPORT, TO CARRY, OR TO COMPRISE SPECIAL LOADS OR OBJECTS
  • B60P1/00—Vehicles predominantly for transporting loads and modified to facilitate loading, consolidating the load, or unloading
  • B60P1/44—Vehicles predominantly for transporting loads and modified to facilitate loading, consolidating the load, or unloading having a loading platform thereon raising the load to the level of the load-transporting element
  • B60P1/4471—General means for controlling movements of the loading platform, e.g. hydraulic systems

Definitions

• the present invention relates to an improvement for a retractable tail lift for a vehicle and more particularly to its management and control system.
• tailgates consist of a lifting platform, connected to the rear of the truck chassis by a set of delivery arms, constituting connection and lifting means, said set of arms being pivotally movable to allow the ascent and descent from the platform.
• the platform must be retracted to be stored, for example under the vehicle, while a set of actuators actuates the various movements of the elements of the tailgate to allow on the one hand the lifting and lowering of the platform but also the maintenance of the latter in a substantially horizontal position, during the ascent and descent of the platform.
• the tailgates comprise one or more jacks called lifting jacks controlling the lifting and lowering of the platform and one or more jacks called tilt jacks positioning the platform relative to the lifting arms.
• This type of tailgate is for example described by the French patent published under the number FR 2786455.
• the present invention intends to innovate in the field of tail lifts by proposing a management and control system, particularly simple, reliable and economical.
• the tail lift comprises management and control means, making it possible in particular to prevent lifting any mass greater than the nominal capacity of the tailgate, which is particularly advantageous when it is known that the European directives on lifting gear require manufacturer to be able to prohibit any dangerous movement.
• the said means of management and control also make it possible to weigh the on-board load, so as to verify that its weight corresponds well to the declarations made, which is of great interest insofar as the carriers invoice their services on the basis of the weight.
• the means of the invention it also becomes possible, during a delivery tour, to check whether the total permissible laden weight of the vehicle remains respected (loading / unloading with only the tailgate), the processor subtracting and adding both to determine the total load present in the truck, and therefore makes it possible to keep track of any overloads, with a history.
• the vehicle tailgate is of the type consisting of an elevating platform connected to the chassis of the vehicle by a set of linkage and lifting arms, while jacks are provided on the one hand move said link arms and on the other hand hold the horizontal platform, during its rise and fall, namely, at least one lifting cylinder ensuring the pivoting of the link and lifting arms and at least one cylinder inclination ensuring the correct position of the platform relative to the arms, and is characterized in that management and control means are provided.
• the management and control means comprise at least sensors and a computerized control module or unit.
• At least one of the lifting cylinders, and at least one of the tilting cylinders comprise a sensor, such as for example an oil pressure sensor which is connected to a computerized control module or unit , while the latter comprises a microprocessor interpreting the signals received from the sensors and calculating the moment of the torque resulting from the effect of the load on the platform, by combination of the two pressure measurements.
• a sensor such as for example an oil pressure sensor which is connected to a computerized control module or unit
• the latter comprises a microprocessor interpreting the signals received from the sensors and calculating the moment of the torque resulting from the effect of the load on the platform, by combination of the two pressure measurements.
• Figure 1 is a side view of the rear of the truck with its tail lift in its folded storage position, the lifting and tilt cylinders known per se not being shown
• Figure 2 is a rear view of the truck.
• FIGS 3, 4 and 5 are the three diagrams of hydraulic circuits given as an example of execution.
• the tailgate according to the invention bearing the general reference (1) is fixed to the rear part of a vehicle, such as a truck or a trailer (3).
• Said tailgate (1) consists of an elevating platform (5) connected to the chassis (4) of the truck by connection and lifting means known per se and consisting of a set of link and lifting arms ( 7) while jacks (8a, 8b- 9a, 9b) are provided to move said link arms and hold the platform horizontal, during its ascent and descent
• lifting cylinders (8a, 8b) ensuring the pivoting of the linkage and lifting arms (7) and tilting cylinders (9a, 9b) ensuring the correct position of the platform (5) by relative to the arms (7).
• At least one of the lifting cylinders (8a, 8b), and at least one of the tilting cylinders (9a, 9b) comprise a sensor, such as for example an oil pressure sensor which is connected to a computerized control module or unit.
• the oil pressure sensors are for example arranged in direct or indirect contact with the oil of each of the corresponding cylinders.
• Each of the sensors therefore sends information to the control module which includes a microprocessor interpreting the signals and calculating the moment of the torque resulting from the effect of the load on the platform, by combining the two pressure measurements. So that, whatever the position of the load on the platform of the tail lift, and taking into account the leverage, the weight of this load is determined.
• the accuracy of the measurement depends of course on the accuracy of the sensors (+/- 5%) and the hysteresis of the cylinders. Accuracy of the “weight and measurement” type can be obtained with more sensitive sensors than those supplied as standard.
• the movements of the tail lift are controlled by an electronic card comprising a microprocessor to which memory has been added (programmable EPROM).
• the memory software controls the opening and closing of the solenoid valves, and therefore the opening and closing of the tilt and lift cylinders, as well as of the retraction or retraction mechanisms of the mechanism.
• control module thanks to its processor and its programming allows:
• the sensors could be of another type than that described above, such as for example a strain gauge or other and / or placed in other places so as to be able to cross the data and thus calculate the moment of the charge.
• FIG 3 is a hydraulic diagram given as a first example of embodiment, according to which one of the lifting cylinders (8) comprises an oil pressure sensor (10).
• Said sensor (10) is for example an all or nothing type sensor, which can have two types of operation. One of the operations being such that it is preset at closing at a pressure of zero bar, and the other operating as it is preset at opening at a determined threshold value corresponding to the maximum authorized pressure.
• two sensors can be used to obtain the two functions mentioned above.
• One of the sensors is for example preset to close at zero bar allowing the detection of the arrival and / or takeoff of the platform relative to the ground and thanks to the module or control unit, controls a relay which switches in operation the action of the tilt cylinders (9) thus ensuring a perfect tilt relative to the ground.
• the other of the sensors is for example preset at the opening to a threshold value or maximum pressure corresponding to the maximum value of the admissible load. As soon as this threshold is reached, the control unit then detects an overload and either triggers an alarm warning the user, or prohibits any movement of the tailgate and for example the raising and / or lowering of the platform.
• FIG. 4 is an illustration of another hydraulic diagram of a second embodiment according to which the sensor (11) disposed on one of the lifting cylinders (8) is a pressure sensor whose electrical signal is proportional with pressure. Said sensor (11) making it possible to obtain the following three functions:
• - weighing that is to say the evaluation and determination of the mass of the load by integrating the value of the pressure measured in a formula taking account of the lever arm, the surfaces of the sections of the jacks and phenomena hysteresis.
• Figure 5 is another embodiment of the hydraulic circuit according to which two sensors are provided, a first pressure sensor (11) on the lifting cylinder (8a) and a second pressure sensor (12) on the cylinder d 'tilt (9a).
• the jacks 21a and 21b are jacks used for the retraction of the entire tailgate on the chassis of the corresponding truck.

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• Engineering & Computer Science (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Fluid-Pressure Circuits (AREA)

Applications Claiming Priority (3)

Publications (1)

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Families Citing this family (7)

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• 2000
  • 2000-08-19 EP EP00958710A patent/EP1121271A1/de not_active Withdrawn
  • 2000-08-19 WO PCT/FR2000/002345 patent/WO2001014167A1/fr not_active Ceased
  • 2000-08-19 AU AU70147/00A patent/AU7014700A/en not_active Abandoned

Non-Patent Citations (1)

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