Hydraulic actuation device, hitch including it and adjustment kit

Abstract

The invention relates to a hydraulic actuation device (1) comprising at least one hydraulic actuating cylinder (A) for moving a movable assembly (M) to a second end-of-stroke position, and a hydraulic assembly (H) for supplying hydraulic fluid to at least one hydraulic actuating cylinder (A), and comprising at least one hydraulic fluid reservoir (T) mounted on a vehicle to which the reference assembly (R) is connected. According to the invention, the device (1) further comprises at least one hydraulic compensating cylinder (2) mechanically connected to the movable assembly (M) and to a reference assembly (R), such that a movement of the movable assembly (M) to the second end-of-stroke position causes a compensating chamber (25) of the compensating cylinder (2) to expel hydraulic fluid into the reservoir (T). The invention also relates to a coupling comprising the device (1) and a corresponding compensation kit.Figure to be published with the abbreviation: Figure 1.

Description

Title of the invention: Hydraulic actuation device, coupling comprising it and compensation kit

[0001] The present invention relates to the technical field of hydraulic systems, and more particularly to a hydraulic actuation device, a coupling comprising it and a recovery kit.

[0002] Tipping trailers comprising a hydraulic actuating cylinder configured to tilt the trailer bed, for example to allow unloading, have been known for a long time. For such trailers, the hydraulic actuating cylinder can be supplied with hydraulic fluid directly from the towing vehicle.

[0003] However, in some cases, when the trailer's loading capacity is significant, the hydraulic actuating cylinder is large and generally of the telescopic type. It is then necessary to inject a large quantity of hydraulic fluid into the actuating cylinder to allow its full extension. In agricultural applications, for example, it may be necessary to inject 40 to 80 liters of oil into the actuating cylinder to fully tilt the trailer bed. However, a number of tractor units have a smaller oil capacity than the volume of oil required to fully extend the actuating cylinder.

[0004] In the prior art, one proposed solution to this problem consists of installing a "hydraulic compressor" on the trailer, that is, a hydraulic pump associated with a hydraulic fluid reservoir, which is driven by the power take-off of the towing vehicle via a cardan shaft. Utility certificate FR2460801 B3, for example, presents a trailer of this type.

[0005] However, such solutions are not very user-friendly, connecting the cardan joint is tedious and it can be a hindrance during maneuvers.

[0006] Therefore, prior art solutions always have drawbacks and improvements are possible.

[0007] The present invention aims in particular to solve the problems indicated above by proposing a hydraulic actuation device, a coupling including it and a recovery kit.

[0008] Thus, the present invention relates to a hydraulic actuation device intended to be used to move a movable assembly, connected to a reference assembly and movable between a first end position and said second end position, to a second end position. hydraulic actuation system comprising at least one hydraulic actuating cylinder, capable, by means of hydraulic fluid injection therein, of moving the moving assembly towards its second end-of-stroke position; and a hydraulic assembly capable of supplying hydraulic fluid to at least one hydraulic actuating cylinder, and comprising at least one hydraulic fluid reservoir mounted on a vehicle to which the reference assembly is connected and receiving a volume of hydraulic fluid called available, i.e., which can be injected into at least one hydraulic actuating cylinder, characterized in that it further comprises at least one compensating hydraulic cylinder mechanically connected, at a first end, to the moving assembly and, at a second end, to the reference assembly,such that a movement of the moving assembly causes a translational movement of a piston of at least one hydraulic compensating cylinder in a body of at least one hydraulic compensating cylinder, each hydraulic compensating cylinder comprising a compensation chamber, which is one of a chamber on the piston rod side and a chamber on the bottom side of the body, suitable for containing hydraulic fluid and fluidically connected to at least one hydraulic fluid reservoir such that as the moving assembly moves towards its second end-of-stroke position, a volume of at least one compensation chamber is progressively reduced and hydraulic fluid contained in said at least one compensation chamber is delivered to at least one hydraulic fluid reservoir for subsequent injection into the hydraulic actuating cylinder,and that, as the moving assembly moves towards its first end-of-stroke position, the volume of at least one compensation chamber is progressively increased and hydraulic fluid is received into said at least one compensation chamber, such that at any position of the moving assembly, between its first end-of-stroke position and its second end-of-stroke position, the volume of available hydraulic fluid is always greater than or equal to zero and is always less than or equal to a maximum capacity of at least one hydraulic fluid reservoir.

[0009] In a hydraulic actuation device as described above, the hydraulic compensating cylinders can automatically exchange hydraulic fluid, for example oil, with the hydraulic fluid reservoir, by means of a hydraulic linkage assembly, so that the hydraulic fluid requirements of the hydraulic actuation cylinders can be met and an excessive influx of hydraulic fluid, beyond the maximum capacity of the hydraulic fluid reservoir, can be prevented.

[0010] It will be understood that the hydraulic actuating cylinders and the hydraulic compensating cylinders can be connected to the moving assembly and the reference assembly by any means. The moving assembly and the reference assembly can by example include fasteners, for example mounting lugs, to allow the connection of hydraulic cylinders.

[0011] According to a particular embodiment, at least one hydraulic compensating cylinder is dimensioned and arranged with respect to the moving assembly and the reference assembly such that during a movement of the moving assembly towards its second end-of-stroke position, at least one piston of at least one hydraulic compensating cylinder displaces, from at least one compensation chamber, a volume of hydraulic fluid corresponding to a volume of the hydraulic fluid injected, by the hydraulic assembly, into at least one hydraulic actuating cylinder, and during a movement of the moving assembly towards its first end-of-stroke position, at least one piston of at least one hydraulic compensating cylinder allows an entry, into at least one compensation chamber, of a volume of hydraulic fluid corresponding to a volume of the hydraulic fluid exiting from at least one hydraulic actuating cylinder.

[0012] It will be understood that such an embodiment makes it possible to maintain a constant volume of hydraulic fluid in the hydraulic fluid reservoir despite the supply of the hydraulic actuating cylinder(s).

[0013] Advantageously, at least one hydraulic compensation cylinder is arranged and dimensioned in such a way that the sum of the volumes, when the moving assembly is in its first end-of-stroke position, of the compensation chambers of each hydraulic compensation cylinder, and of the volume of hydraulic fluid available from at least one hydraulic fluid reservoir is greater than or equal to the so-called full actuation volume of the hydraulic actuation cylinder, that is to say the volume of hydraulic fluid that must be injected to fully actuate it, from the first end-of-stroke position, to the second end-of-stroke position of the moving assembly.

[0014] According to a particular embodiment, for at least one of the hydraulic compensation cylinders, the chamber opposite the compensation chamber, i.e. the other between the chamber on the piston rod side and the chamber on the bottom of the body side, is open to air.

[0015] It will be understood that this embodiment makes it easier to move the piston in the body of the compensating cylinder.

[0016] According to a particular embodiment, for at least one of the hydraulic compensation cylinders, the compensation chamber is the rod-side chamber of the piston.

[0017] According to a particular embodiment, the at least one hydraulic actuating cylinder is in fluidic connection with the at least one hydraulic compensating cylinder only via the hydraulic fluid reservoir. In this case, the hydraulic fluid received in said at least one compensating chamber as from a movement of the moving assembly towards its first end-of-stroke position, comes from at least one hydraulic fluid reservoir.

[0018] Advantageously, the hydraulic actuation device further comprises at least one controlled one-way bypass valve, placed between at least one hydraulic actuating cylinder and at least one hydraulic compensating cylinder, so as to permit a transfer of hydraulic fluid from at least one hydraulic actuating cylinder directly to at least one compensating chamber only when at least one controlled one-way bypass valve receives a bypass control signal, such that hydraulic fluid received in said at least one compensating chamber, as the moving assembly moves towards its first end-of-stroke position, comes directly from at least one actuating cylinder.

[0019] The invention also relates to a coupling comprising a tractor vehicle and an accessory coupled to the tractor vehicle, characterized in that the coupling includes a hydraulic actuation device as described above, the hydraulic assembly being a hydraulic assembly of the tractor vehicle, the at least one hydraulic actuation cylinder being at least one cylinder of the accessory, the moving assembly being a moving element of the accessory moved by the at least one hydraulic actuation cylinder, and the reference assembly being a chassis of the accessory.

[0020] It will be understood that the accessory can be of any type, such as for example a trailer, an edge trimmer or a hedge trimmer for tractors.

[0021] According to a particular embodiment, at least one hydraulic actuating cylinder is mounted to rotate the moving assembly relative to the reference assembly.

[0022] According to a preferred embodiment, the accessory is a tipping trailer, the at least one hydraulic actuation cylinder being a tipping cylinder of the trailer, the moving assembly being a pivoting tipper of the trailer, the reference assembly being the chassis of the trailer, the first end-of-stroke position being a so-called transport position in which the tipper rests on the chassis, and the second end-of-stroke position being a so-called unloading position in which the tipper is inclined relative to the chassis.

[0023] According to a particular embodiment, at least one hydraulic actuating cylinder is mounted to move the moving assembly in translation relative to the reference assembly.

[0024] The invention also relates to a compensation kit for obtaining a coupling as described above, characterized in that it comprises at least one hydraulic compensation cylinder, fastening elements configured to fix the at least one hydraulic compensation cylinder, at one end, to a chassis of the accessory and, at the other end, to a moving assembly of the accessory, such that a displacement of the moving assembly causes a translational displacement of a piston of at least one hydraulic compensating cylinder in a body of at least one hydraulic compensating cylinder, and a hydraulic linkage assembly configured to fluidically connect a compensation chamber of at least one hydraulic compensating cylinder, which is one of a chamber on the piston rod side and a chamber on the bottom side of the body and which contains hydraulic fluid, to at least one hydraulic fluid reservoir of the tractor vehicle intended to supply at least one actuating cylinder of the accessory with hydraulic fluid, such that as the moving assembly moves towards a second end-of-stroke position,The volume of at least one compensation chamber is progressively reduced, and hydraulic fluid contained in said at least one compensation chamber is delivered to at least one hydraulic fluid reservoir; and as the moving assembly moves towards its first end-of-stroke position, the volume of at least one compensation chamber is progressively increased, and hydraulic fluid is received into said at least one compensation chamber.

[0025] It will be understood that a kit such as the one described above makes it possible to implement the present invention while retaining an existing tractor vehicle and / or an existing accessory, for example a tipping trailer.

[0026] Advantageously, the recovery kit further includes at least one controlled one-way bypass valve, configured to be placed between at least one hydraulic actuating cylinder and at least one hydraulic compensating cylinder, so as to allow a transfer of hydraulic fluid from at least one hydraulic actuating cylinder directly to at least one compensating chamber only when at least one controlled one-way bypass valve receives a bypass control signal.

[0027] We will now describe particular embodiments of the present invention, with reference to the attached drawings.

[0028] On these drawings:

[0029] [Fig-1] is a schematic representation of a hy actuation device draulique according to a first embodiment of the present invention;

[0030] [Fig.2] is a schematic representation of a hy actuation device draulique according to a second mode of realization;

[0031] [Fig.3] is a schematic representation of a hy actuation device draulique according to a third mode of realization;

[0032] [Fig.4] is a schematic representation of a hy actuation device draulic according to a fourth mode of realization;

[0033] [Fig.5] is a schematic representation of a hy- actuation device draulic according to a fifth mode of embodiment;

[0034] [Fig.6] is a side section view of a tipping trailer of a coupling according to a preferred embodiment of the present invention, with the tipper in its first end-of-travel position, known as the transport position.

[0035] [Fig.7] is a side cross-sectional view of the trailer of [Fig.6], with the tipper in its second end-of-travel position, known as the unloading position.

[0036] Referring first to Figures 1 to 5, one can see that a hydraulic actuation device 1 is schematically represented therein according to five embodiments of the present invention. The hydraulic actuation device 1 is configured for use in combination with a moving assembly M and a reference assembly R, and comprises a hydraulic actuating cylinder A and a hydraulic assembly H. The hydraulic fluid is, for example, oil suitable for use in hydraulic actuation systems.

[0037] The moving assembly M is movable relative to the reference assembly R, between a first end-of-stroke position and a second end-of-stroke position. It will be understood that the reference assembly R can also be movable relative to a fixed frame of reference.

[0038] In the embodiments shown in Figures 1 to 3, the moving assembly M is mobile by pivoting around a pivot axis L. The pivot axis L can, for example, be obtained by a pivot joint or a ball joint.

[0039] In the embodiments shown in Figures 4 and 5, the moving assembly M is mobile by translation relative to the reference assembly R. In the embodiment shown in [Fig.5], the hydraulic actuating cylinder A bears on a support element R'.

[0040] The moving assembly M can be moved to its second end-of-stroke position by the hydraulic actuating cylinder A when hydraulic fluid is injected into the hydraulic actuating cylinder A using the hydraulic assembly H. Movement to the second end-of-stroke position is indicated by arrow IL

[0041] The moving assembly M can be moved to its first end-of-stroke position by an external element, such as the moving assembly M's own weight, an external load applied to the moving assembly M, the action of an external actuator, for example a cylinder, or an elastic force element E, for example a spring as shown in [Fig. 4]. It will be understood that an elastic force element E can be located inside or outside the hydraulic actuating cylinder A. A movement to the first end-of-stroke position is indicated by arrow I.

[0042] The hydraulic actuating cylinder A can be a single-acting hydraulic cylinder. The hydraulic actuating device 1 according to the invention is particularly suitable for use with a telescopic type A hydraulic cylinder.

[0043] According to embodiments, the hydraulic actuating cylinder A can be actuated by the hydraulic assembly H so as to extend towards the second end-of-stroke position, for example as shown in Figures 1 to 3 and 5, or so as to retract towards the second end-of-stroke position, for example as shown in [Fig.4].

[0044] The hydraulic assembly H includes a hydraulic pump P configured to inject hydraulic fluid into the actuating cylinder A, so as to actuate the actuating cylinder A. The hydraulic assembly H also includes a hydraulic fluid reservoir T, receiving an available volume of hydraulic fluid, which is fluidically connected to the hydraulic pump P.

[0045] Available hydraulic fluid volume means a volume of hydraulic fluid that can be injected into the hydraulic actuating cylinder A by the hydraulic pump P, at a given instant.

[0046] It will be understood that the volume of hydraulic fluid available may be limited by the capacity of the hydraulic fluid reservoir T, or by the hydraulic fluid supply requirements of another device supplied with hydraulic fluid by the hydraulic assembly H, for example another hydraulic actuator.

[0047] It will also be understood that, alternatively, the hydraulic assembly H can include several hydraulic fluid reservoirs T, and that in this case the available hydraulic fluid volume can be distributed in several hydraulic fluid reservoirs T.

[0048] Preferably, the available hydraulic fluid volume of the hydraulic assembly H is less than a full actuation volume, i.e. a volume of hydraulic fluid that must be injected into the hydraulic actuating cylinder A to fully actuate the hydraulic actuating cylinder A towards the second end-of-stroke position of the moving assembly M.

[0049] It will be understood that, alternatively, there may be several actuating cylinders A, and that in this case the complete actuating volume is that of all the actuating cylinders A.

[0050] In the embodiments shown in Figures 1 to 5, the hydraulic actuation device 1 further comprises a hydraulic compensating cylinder 2, comprising a body 21 in which a piston 22 moves in translation. The body 21 and the piston 22 may have circular cross-sections, as for a conventional hydraulic cylinder, but their shape is not limited by the present invention and may, for example, be square.

[0051] The hydraulic compensation cylinder 2 is configured to be mechanically connected, at one end, to the moving assembly M and, at the other end, to the reference assembly R, such that a displacement of the moving assembly M causes a displacement The piston 22 of the hydraulic compensating cylinder 2 moves within the body 21 of the hydraulic compensating cylinder 2. The mechanical connections between the hydraulic compensating cylinder 2 and the moving assembly M, and between the hydraulic compensating cylinder 2 and the reference assembly R, can be achieved, for example, using pivot joints or ball joints. Furthermore, the moving assembly M and the reference assembly R can, for example, include fastening elements, such as mounting lugs, to allow the connection of the hydraulic compensating cylinder 2. As shown in Figures 1 to 5, a head of the piston 22 of the hydraulic compensating cylinder 2 defines, within its body 21, a chamber 23 on the piston rod side and a chamber 24 on the bottom side of the body 21, the respective volumes of which vary according to the displacements of the piston 22 within the body 21.

[0052] In addition, the hydraulic compensation cylinder 2 includes a so-called compensation chamber 25 which can correspond either to the rod-side chamber 23 or to the bottom-side chamber 24, depending on the embodiment.

[0053] The compensation chamber 25 corresponds to the chamber 23, 24 whose volume decreases when the moving assembly M is moved towards its second end-of-stroke position, and whose volume increases when the moving assembly M is moved towards its first end-of-stroke position.

[0054] For example, the compensation chamber 25 corresponds to the stem-side chamber 23 for the embodiments shown in Figures 1 and 2, and the compensation chamber 25 corresponds to the bottom-side chamber 24 for the embodiments shown in Figures 3 to 5.

[0055] The compensation chamber 25 is configured to receive hydraulic fluid, and to be fluidically connected to the hydraulic fluid reservoir T of the hydraulic assembly H, in order to be able to exchange hydraulic fluid with the hydraulic fluid reservoir T. The compensation chamber 25 can be directly connected to the hydraulic fluid reservoir T, for example as shown in Figures 1 to 4, or can be connected to the hydraulic fluid reservoir T via the hydraulic pump P, for example as shown in [Fig.5], for example to assist a movement of hydraulic fluid.

[0056] Thus, when the actuating cylinder A is actuated by the hydraulic assembly H, the moving assembly M is moved to its second end-of-stroke position, consequently the piston 22 of the hydraulic compensation cylinder 2 is driven in translation in the body 21, the volume of the compensation chamber 25 is progressively reduced, and hydraulic fluid contained in the compensation chamber 25 is expelled from the compensation chamber 25 and delivered to the hydraulic fluid reservoir T to then be available, if needed, for injection into the actuating cylinder A.

[0057] Conversely, when the moving assembly M is moved towards its first end-of-stroke position, the piston 22 of the hydraulic compensation cylinder 2 is driven in translation in the body 21, the volume of the compensation chamber 25 is progressively increased, and hydraulic fluid contained in the hydraulic fluid reservoir T is admitted into the compensation chamber 25.

[0058] Consequently, the compensation cylinder 2 automatically exchanges hydraulic fluid with the hydraulic fluid reservoir T as a function of a displacement of the moving assembly M.

[0059] According to variants, and as shown in dotted lines in Figures 1 to 5, the hydraulic actuation device 1 may further include a one-way controlled bypass valve C connected on one side to the hydraulic actuating cylinder A and on the other side to the compensation chamber 25 of the hydraulic compensation cylinder 2. The one-way controlled bypass valve C is arranged to allow hydraulic fluid to flow directly from the hydraulic actuating cylinder A to the compensation chamber 25 when the one-way controlled bypass valve C receives a bypass control signal, and to prevent any passage of hydraulic fluid in the absence of a bypass control signal.

[0060] The bypass control signal can, for example, be a hydraulic signal, an electrical signal, or a manual control exercised directly by a user.

[0061] The hydraulic actuation device 1 can thus be configured so that, when the user decides to move the moving assembly M towards its first end-of-stroke position, a bypass control signal is transmitted to the controlled one-way bypass valve C. The hydraulic actuation cylinder A then empties directly into the compensation chamber 25 under the effect of the own weight of the moving assembly M displacing hydraulic fluid from the hydraulic actuation cylinder A and under the effect of a suction of hydraulic fluid towards the compensation chamber 25 caused by the movement of the piston 22 in the body 21 of the hydraulic compensation cylinder 2, which is driven by the movement of the moving assembly M.

[0062] It will be understood, however, that preferably the hydraulic actuation device 1 is configured such that if no bypass control signal is sent to the controlled one-way bypass valve C when movement to the first end-of-stroke position is desired, or if the compensation chamber 25 becomes filled, hydraulic fluid present in the hydraulic actuating cylinder A can be emptied into the hydraulic fluid reservoir T in the same way as in embodiments without a one-way valve. controlled bypass C.

[0063] Furthermore, during a movement of the moving assembly M towards its second end-of-stroke position, the operation of the hydraulic actuation device 1 is identical to that of the embodiments without a one-way controlled bypass valve C, that is to say that hydraulic fluid is expelled from the compensation chamber 25 towards the hydraulic fluid reservoir T, is drawn in by the hydraulic pump P and is injected into the hydraulic actuation cylinder A.

[0064] Preferably, the chamber 23, 24 of the hydraulic compensation cylinder 2 opposite the compensation chamber 25, i.e. the chamber 23, 24 which is not the compensation chamber 25, is open to air, for example to facilitate a movement of the piston 22 in the body 21.

[0065] According to a particular embodiment of the present invention, the compensation chamber 25 is dimensioned and the hydraulic compensation cylinder 2 is arranged with respect to the moving assembly M and the reference assembly R, such that in use, a volume of hydraulic fluid exiting the hydraulic compensation cylinder 2, respectively entering the hydraulic compensation cylinder 2, corresponds to a volume of hydraulic fluid entering the hydraulic actuating cylinder A, respectively exiting the hydraulic actuating cylinder A. In this way, the volume of hydraulic fluid available in the hydraulic fluid reservoir T is not modified due to the use of the hydraulic actuating cylinder A.

[0066] According to another particular embodiment of the invention, the compensating hydraulic cylinder 2 can be sized and arranged such that, in use, a volume of hydraulic fluid exiting the compensating hydraulic cylinder 2 is less than a volume of hydraulic fluid entering the actuating hydraulic cylinder A. It will also be understood that in this case, the compensating hydraulic cylinder 2 is sized and arranged such that, over the range of movement of the moving assembly M between its first end-of-stroke position and its second end-of-stroke position, a difference between a volume of hydraulic fluid exiting the compensating hydraulic cylinder 2 and a volume of hydraulic fluid entering the actuating hydraulic cylinder A is less than the volume of available hydraulic fluid received in the hydraulic fluid reservoir T.

[0067] According to a particular embodiment of the invention, the hydraulic compensating cylinder 2 is arranged with respect to the moving assembly M and the reference assembly R such that the compensating chamber 25 is empty when the moving assembly M is in its second end-of-stroke position. The hydraulic compensating cylinder 2 is then preferably designed and dimensioned such that the sum of the volume of the compensating chamber 25 of the hydraulic compensating cylinder 2, When the moving assembly is in its first end-of-stroke position, and the available hydraulic fluid volume in the hydraulic fluid reservoir T of the hydraulic assembly H is greater than or equal to the full actuation volume, then, if we denote VA as the full actuation volume, VD as the available hydraulic fluid volume, and V25 as the volume of the compensation chamber 25 when the moving assembly is in its first end-of-stroke position, then the following equation is satisfied:

[0068] VA <VD+V25

[0069] It will be understood that the volume of hydraulic fluid exchanged by the compensating hydraulic cylinder 2 with the hydraulic fluid reservoir T, over the range of movement of the moving assembly between the first and second end-of-stroke positions, depends directly on the cross-section of the body 21 and the stroke of the piston 21. It will therefore be understood that it is possible to adjust the volume of hydraulic fluid exchanged by the compensating hydraulic cylinder 2, with the hydraulic fluid reservoir T, by selecting dimensions of the cross-section of the body 21 and a positioning of the compensating hydraulic cylinder 2 with respect to the moving assembly M and the reference assembly R.

[0070] It will also be understood that, alternatively, the hydraulic actuation device 1 could comprise several hydraulic compensating cylinders 2 instead of the single hydraulic compensating cylinder 2 shown for each embodiment of Figures 1 to 5, or several hydraulic compensating cylinders 2 arranged according to combinations of the embodiments shown in Figures 1 to 5. In this case, the total volume of the compensating chamber 25 of the compensating cylinder 2 corresponds to the sum of the compensating chambers 25 of each hydraulic compensating cylinder 2 of the hydraulic actuation device 1.

[0071] The hydraulic actuation device 1 according to the invention therefore makes it possible to compensate for variations in the volume of hydraulic fluid in the hydraulic fluid reservoir T during operation of the hydraulic actuating cylinder A, so that the hydraulic assembly H is able to fully actuate the hydraulic actuating cylinder A even if the volume of hydraulic fluid available is less than the full actuation volume.

[0072] The hydraulic actuation device 1 according to the invention can be used in many applications, such as tipping trailers or tractor edgers or hedge trimmers.

[0073] It can be specified that the hydraulic actuation device 1 as shown in [Fig. 1], with or without a controlled one-way bypass valve C, is particularly suitable for a tipper trailer type application 3, as shown in Figures 6 and 7, comprising a chassis 31, coupled to a vehicle tractor V. Preferably, the hydraulic assembly H is a hydraulic assembly H of the tractor vehicle V, the hydraulic actuating cylinder A is a tipping cylinder 33 of the trailer 3, the moving assembly M is a pivoting tipper 32 of the trailer 3 mounted pivotally at one end of the chassis 31, the reference assembly R is the chassis 31 of the trailer, the first end-of-stroke position is a so-called transport position in which the tipper 32 rests on the chassis 31, and the second end-of-stroke position is a so-called unloading position in which the tipper 32 is inclined relative to the chassis 31.

[0074] The tipper 32 is preferably mounted pivotally using pivot links, but could also be mounted on the chassis using ball joints.

[0075] According to the embodiment shown in Figures 6 and 7, the chassis 31 comprises three axles 311 each equipped with two wheels, one on each side of the trailer 3. It will be understood, however, that alternatively the chassis 31 may comprise a different number of axles 311, for example one or two, and that each axle may comprise a different number of wheels, for example two wheels on each side of the trailer 3.

[0076] The chassis 31 also includes a coupling device 312 mounted on the chassis 31 at the opposite end from the end to which the tipper body 32 is pivotally mounted. The coupling device 312 is configured to couple the trailer 3 to a tractor vehicle V. The hydraulic assembly H includes a hydraulic fluid reservoir T and a hydraulic pump P fluidically connected to the hydraulic fluid reservoir T.

[0077] The tipping cylinder 33 is a hydraulic and telescopic cylinder, which is mounted on one side body to a central part of the chassis 31 and on one side rod to a central part of the tipper 32, oriented towards the chassis, using pivot links or ball joints.

[0078] The tipping cylinder 33 is supplied with fluid by means of the pump P of the hydraulic assembly H so that it can be deployed. The hydraulic fluid reservoir T receives a volume of available hydraulic fluid, that is to say, a volume of hydraulic fluid that can be injected into the tipping cylinder 33 by the hydraulic pump P. The volume of available hydraulic fluid is limited by the capacity of the hydraulic fluid reservoir T, and by the hydraulic fluid supply requirements of the other devices of the tractor vehicle V supplied with hydraulic fluid by the hydraulic assembly H, for example other hydraulic actuators.

[0079] The tipping cylinder 33 is configured to pivot the tipper 32 from a first end-of-stroke position, known as the transport position, in which the tipper 32 rests on the chassis 31 and the tipping cylinder 33 is retracted, to a second end-of-stroke position, known as the unloading position, in which the tipper 32 is inclined relative to the chassis 31 and the tipping cylinder 33 is extended. Once in its second position At the end of its travel, the skip 32 can return to its first end-of-travel position under the effect of its own weight.

[0080] The hydraulic compensation cylinder 2 is mounted on one side body 21 to the chassis 31 and on one side piston rod 22 to the tipper 32, between the tipping cylinder 33 and the end of the chassis 31 to which the tipper 32 is pivotally mounted, using pivot links or ball joints.

[0081] The compensation chamber 25 is the chamber on the rod side 23 and is configured to receive hydraulic fluid. It will therefore be understood that a volume of the compensation chamber 25 is progressively reduced when the bucket 32 ​​is moved towards its second end-of-stroke position, and is progressively increased when the bucket 32 ​​is moved towards its first end-of-stroke position.

[0082] The compensation chamber 25 is also fluidically connected to the hydraulic fluid reservoir T, in order to be able to exchange hydraulic fluid with the hydraulic fluid reservoir T.

[0083] Thus, in use, when the tipping cylinder 33 is supplied with fluid by the hydraulic assembly H, the telescopic tipping cylinder 33 extends, the tipper 32 is moved to its second end-of-stroke position, the piston 22 of the compensating hydraulic cylinder 2 is made to slide in the body 22 such that the piston 22 expels hydraulic fluid from the compensation chamber 25, which fluid is delivered to the hydraulic fluid reservoir T. Thus, a volume of hydraulic fluid injected into the tipping cylinder 33 is compensated by a volume of fluid exiting the compensating cylinder 2.

[0084] Conversely, when the tipper 32 is moved towards its first end-of-stroke position, for example under the effect of its own weight, the piston 22 of the hydraulic compensation cylinder 2 is made to slide in the body 22 in such a way that the piston 22 allows an admission of hydraulic fluid into the compensation chamber 25, from the hydraulic fluid reservoir T and / or directly from the tipping cylinder 33 for the variant with controlled one-way bypass valve C.

[0085] The compensation cylinder 2 is designed and arranged on the trailer 3 so that the compensation chamber 25 is empty when the tipper 32 is in its second end-of-stroke position.

[0086] The chamber opposite the compensation chamber 25, here the bottom-side chamber 24, is open to air to facilitate sliding of the piston 22 in the body 21.

[0087] Furthermore, the cross-section of the body 21 is chosen such that, over the range of motion of the bucket 32 ​​between its first end-of-stroke position and its second end-of-stroke position, a volume of hydraulic fluid exiting the compensation chamber 25 is equal to a full actuation volume, i.e. a volume of hydraulic fluid to be injected into the tipping cylinder 33 to fully deploy it in order to bring the tipper 32 into its second end-of-stroke position.

[0088] It will be understood that, if the volume of hydraulic fluid available in the tractor vehicle V to which the trailer will be attached is known in advance, it is possible to use a smaller compensating hydraulic cylinder 2. The compensating hydraulic cylinder 2 must then be sized and positioned on the trailer 3, ensuring that, in operation, the sum of the volume of hydraulic fluid exiting the compensating hydraulic cylinder 2 and the volume of hydraulic fluid available in the tractor vehicle V is greater than the full actuation volume.

[0089] A tipping trailer 3 according to the invention therefore has, in particular, the advantage of being able to be directly operated by the hydraulic assembly H of the tractor vehicle V, even when the volume of hydraulic fluid available, received in the hydraulic fluid reservoir T, is less than the full actuation volume of the tipping cylinder 33.

[0090] It is understood that the embodiments which have just been described have been given by way of indication and not limitation and that embodiments may be added to them without departing from the scope of the present invention.

Claims

1. Demands Hydraulic actuation device (1) intended to be used to move a movable assembly (M), connected to a reference assembly (R) and movable between a first end position and said second end position, to a second end position, the hydraulic actuation device comprising: - at least one hydraulic actuation cylinder (A), at least capable, by means of an injection of hydraulic fluid into it, of moving the moving assembly (M) towards its second end-of-stroke position; - a hydraulic assembly (H) capable of supplying hydraulic fluid to at least one hydraulic actuating cylinder (A), and comprising at least one hydraulic fluid reservoir (T) mounted on a vehicle to which the reference assembly (R) is connected and receiving a volume of hydraulic fluid said to be available, i.e. that can be injected into at least one hydraulic actuating cylinder (A), characterized in that it further comprises at least one hydraulic compensating cylinder (2) mechanically connected, at a first end, to the moving assembly (M) and, at a second end, to the reference assembly (R), such that a displacement of the moving assembly (M) causes a translational displacement of a piston (22) of at least one hydraulic compensating cylinder (2) in a body (21) of at least one hydraulic compensating cylinder (2), each hydraulic compensating cylinder (2) comprising a compensation chamber (25), which is one of a chamber (23) on the piston rod side (22) and a chamber (24) on the bottom side of the body (21), suitable for containing hydraulic fluid and fluidically connected to at least one hydraulic fluid reservoir (T) such that: - that as the moving assembly (M) moves towards its second end-of-stroke position, a volume of at least one compensation chamber (25) is progressively reduced and hydraulic fluid contained in said at least one compensation chamber (25) is delivered to at least one hydraulic fluid reservoir (T) in order to then be

2. injected into the hydraulic actuating cylinder (1), and - that as the moving assembly (M) moves towards its first end-of-stroke position, the volume of at least one compensation chamber (25) is progressively increased and hydraulic fluid is received into said at least one compensation chamber (25), such that at any position of the moving assembly (M), between its first end-of-stroke position and its second end-of-stroke position, the volume of available hydraulic fluid is always greater than or equal to zero and is always less than or equal to a maximum capacity of at least one hydraulic fluid reservoir (T), the hydraulic actuation device (1) further comprising at least one controlled one-way bypass valve (C), placed between at least one hydraulic actuating cylinder (A) and at least one hydraulic compensating cylinder (2), so as to permit a transfer of hydraulic fluid from at least one hydraulic actuating cylinder (A) directly to at least one compensating chamber (25) only when at least one controlled one-way bypass valve (C) receives a bypass control signal, such that hydraulic fluid received in said at least one compensating chamber (25), as the moving assembly (M) moves towards its first end-of-stroke position, comes directly from at least one actuating cylinder (A). Device (1) according to claim 1, characterized in that at least one hydraulic compensating cylinder (2) is dimensioned and arranged with respect to the moving assembly (M) and the reference assembly (R) such that: - during a movement of the moving assembly (M) towards its second end-of-stroke position, at least one piston (22) of at least one hydraulic compensation cylinder (2) displaces, from at least one compensation chamber (25), a volume of hydraulic fluid corresponding to a volume of hydraulic fluid injected, by the hydraulic assembly (H), into at least one hydraulic actuating cylinder (A), and - during a movement of the moving assembly (M) towards its first end-of-stroke position, at least one piston (22) of at least one hydraulic compensation cylinder (2) allows an entry, into at least one compensation chamber (25), of a volume of hydraulic fluid corresponding to a volume of hydraulic fluid exiting at least one hydraulic actuating cylinder (A).

3. Device (1) according to any one of claims 1 or 2, characterized in that at least one hydraulic compensation cylinder (2) is arranged and dimensioned in such a way that the sum of the volumes, when the moving assembly (M) is in its first end-of-stroke position, of the compensation chambers (25) of each hydraulic compensation cylinder (2), and of the available hydraulic fluid volume of at least one hydraulic fluid reservoir (T) is greater than or equal to the so-called full actuation volume of the hydraulic actuating cylinder (A), that is to say the volume of hydraulic fluid that must be injected to fully actuate it, from the first end-of-stroke position, to the second end-of-stroke position of the moving assembly (M).

4. Device (1) according to any one of claims 1 to 3, characterized in that, for at least one of the hydraulic compensation cylinders (2), the chamber opposite the compensation chamber (25), i.e. the other among the chamber (23) on the piston rod side (22) and the chamber (24) on the bottom side of the body (21), is open to air.

5. Device (1) according to any one of claims 1 to 4, characterized in that, for at least one of the hydraulic compensation cylinders (2), the compensation chamber (25) is the chamber (23) on the rod side of the piston (22).

6. A coupling comprising a towing vehicle (V) and an attachment coupled to the towing vehicle (V), characterized in that the coupling comprises a device (1) according to any one of claims 1 to 5, the hydraulic assembly (H) being a hydraulic assembly (H) of the towing vehicle (V), the at least one hydraulic actuating cylinder (A) being at least one cylinder of the attachment, the moving assembly (M) being a moving element of the attachment moved by the at least one hydraulic actuating cylinder (A), and the reference assembly (R) being a accessory chassis.

7. Coupling according to claim 6, characterized in that at least one hydraulic actuating cylinder (A) is mounted to pivot the moving assembly (M) relative to the reference assembly (R).

8. Coupling according to claim 7, characterized in that the accessory is a tipping trailer (3), at least one hydraulic actuating cylinder (A) being a tipping cylinder (33) of the trailer (3), the moving assembly (M) being a pivoting tipper (32) of the trailer (3), the reference assembly (R) being the chassis (31) of the trailer (3), the first end-of-stroke position being a so-called transport position in which the tipper (32) rests on the chassis (31), and the second end-of-stroke position being a so-called unloading position in which the tipper (32) is inclined relative to the chassis (31).

9. Coupling according to claim 6, characterized in that at least one hydraulic actuating cylinder (A) is mounted to move the moving assembly (M) in translation relative to the reference assembly (R).

10. A compensation kit for achieving a coupling according to any one of claims 6 to 9, characterized in that it comprises: - at least one hydraulic compensating cylinder (2), - fastening elements configured to fix the at least one hydraulic compensating cylinder (2), at one end, to a frame (31) of the attachment and, at the other end, to a moving assembly (M) of the attachment, such that a displacement of the moving assembly (M) causes a translational displacement of a piston (22) of the at least one hydraulic compensating cylinder (2) within a body (21) of the at least one hydraulic compensating cylinder (2), and - a hydraulic linkage assembly configured to fluidly connect a compensating chamber (25) of the at least one hydraulic compensating cylinder (2), which is one of a chamber (23) on the piston rod side (22) and a chamber (24) on the bottom side of the body (21) and which contains hydraulic fluid,to at least one hydraulic fluid reservoir (T) of the tractor vehicle (V) intended to supply at least one actuating cylinder (A) of the accessory with hydraulic fluid, such that as the moving assembly (M) moves towards a second end-of-stroke position, the volume of at least one compensation chamber (25) is progressively reduced and hydraulic fluid contained in said at least one compensation chamber (25) is delivered to at least one hydraulic fluid reservoir (T), and that as the moving assembly (M) moves towards its first end-of-stroke position, the volume of at least one compensation chamber (25) is progressively increased and hydraulic fluid is received into said at least one compensation chamber (25), and - at least one controlled one-way bypass valve (C), configured to be placed between at least one hydraulic actuating cylinder (A) and at least one hydraulic compensating cylinder (2), so as to permit a transfer of hydraulic fluid from at least one hydraulic actuating cylinder (A) directly to at least one compensating chamber (25) only when at least one controlled one-way bypass valve (C) receives a bypass control signal.

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