WO2018055298A1

WO2018055298A1 - Hydraulic control system

Info

Publication number: WO2018055298A1
Application number: PCT/FR2017/052541
Authority: WO
Inventors: Louis-Claude Porel
Original assignee: Hydro Leduc
Priority date: 2016-09-22
Filing date: 2017-09-21
Publication date: 2018-03-29
Also published as: FR3056266A1

Abstract

The invention concerns a hydraulic control system (1) comprising a plurality of hydraulic cylinders (A, B) intended to be actuated in a synchronised manner, each hydraulic cylinder comprising a barrel having an internal space and a piston (3a, 3b) dividing the internal space of the barrel into a first chamber (4a, 4b) and a second chamber (5a, 5b), a volume flow rate divider/multiplexer (10) having a common port and a plurality of parallel ports (12a, 12b), a plurality of control lines (6a, 6b) each linking a respective parallel port to the first chamber of a respective hydraulic cylinder, and a hydraulic locking device (30) comprising a first supply-side port (31a) intended to be connected to a pressure source, a connecting channel connecting the first supply-side port to the common port (11), and a non-return member arranged in the connecting channel and having a throughflow direction from the first supply-side port towards the common port.

Description

HYDRAULICALLY CONTROLLED SYSTEM

Technical area

The invention relates to the field of jack systems intended to be actuated synchronously, in particular hydraulically controlled lifting systems.

Technological background

Lifting systems are used in many applications such as transporting luggage to and from the hold of an aircraft or transporting motor vehicles by rail and road on rail cars and carriages. When a platform or a loaded structure must be raised by several jacks in a given orientation, for example horizontal, it is important that the jacks are operated in a synchronized manner regardless of the load they support, including if this load n is not evenly distributed over the cylinders. Otherwise, synchronization faults may lead to jamming or damage to the hoisting system.

US6068064 discloses an agricultural tool comprising two jacks fed by a simple branch connection. This tool does not require a high degree of synchronization of the two cylinders.

summary

An idea underlying the invention is to provide a hydraulically controlled system in which the actuation of several jacks can be synchronized and in which the jacks can be locked in different positions without loss of synchronization, thanks to a locking device common hydraulics. An object of the invention is to obtain a control device of several cylinders which can maintain a good synchronization even in case of leakage of the hydraulic locking device. Another object of the invention is to obtain a device for controlling a plurality of jacks which employs a single locking device.

According to one embodiment, the invention provides an actuation system, for example a hydraulically controlled lifting system, comprising: a plurality of jacks for being actuated synchronously, each cylinder having a cylinder having an interior space and a piston dividing the interior of the cylinder into a first chamber and a second chamber, the piston being movable in the cylinder in a race of displacement, a volumetric flow divider-combiner having a common port and a plurality of parallel ports, the volumetric flow divider-combiner configured to divide a total incoming flow by the common port into a plurality of partial flows out through the parallel ports and, in combinator operation, combining a plurality of partial flows entering by the parallel ports into a total outflow through the common port, the volumetric flow divider-combiner having an associated pressure compensation device at each parallel port to set the ratio volumetric between the partial flow of the parallel port and the total flow rate independently of an operating pressure of said parallel port,

a plurality of control lines each connecting a respective parallel port of the volumetric flow divider-combiner to the first chamber of a respective cylinder, and

a hydraulic locking device having a first supply side port for connection to a pressure source, a second supply side port, a connecting channel connecting the first supply side port to the common port of the volumetric flow divider / combiner, an non-return device arranged in the connecting channel and having a forward direction from the first power-side port to the common port of the volumetric flow divider-combiner and a sense blocking from the common port of the volumetric flow divider-combiner to the first port power supply side, and a pilot device configured to open the non-return member in response to a control pressure applied to the second power-side port.

With these features, the cylinders can be actuated to actuating positions by applying pressure to the first power-side port of the hydraulic lock. Thanks to the volumetric flow divider-combiner, the various cylinders are actuated in proportions well controlled, equal or not, depending on volumetric ratios fixed. In addition, the cylinders can be locked in an actuated position by means of the hydraulic locking device and its non-return device when the first applied pressure on the supply side is removed. Finally, thanks to the volumetric flow divider-combiner interposed between the cylinders and the hydraulic locking device, no loss of synchronization occurs even if the sealing of the hydraulic locking device is defective. In this context, the synchronization between the cylinders designates the fact that the actuators are actuated in well-controlled proportions, these proportions being equal to or different from one another and being programmed by the distribution law of the divider-flow combiners volumetric.

According to advantageous embodiments, such a device may have one or more of the following characteristics.

In one embodiment, the plurality of control lines is a first plurality of control lines, the system further comprising a branch branch branch connector and a second plurality of control lines each connecting a respective branch of the branch connector. to the second chamber of a respective cylinder. Thanks to these characteristics, the second chambers of all the cylinders can be connected economically and simply to a source of high or low pressure, via the branch connection. The use of a second volumetric flow divider-combiner is not necessary.

Preferably in this case, the connecting channel and the non-return member of the hydraulic locking device are a first connecting channel and a first non-return member, the hydraulic locking device further comprising a second connecting channel connecting the second port on the supply side to the branch connection, a second non-return device arranged in the second connecting channel and having a forward direction from the second port on the supply side to the branch connection and a blocking direction from the branch connection to the second power-side port, wherein the pilot device is configured to open the second non-return member in response to a control pressure applied to the first power-side port. Thanks to these characteristics, the hydraulic flows in and out of the second cylinder chambers can also pass through the hydraulic locking device, which facilitates the installation of the system.

In one embodiment, the first non-return member and / or the second non-return member comprises at least two non-return valves arranged in series in the connecting channel. Preferably, the two non-return valves arranged in series are different from each other as to the geometry and / or the material. Thanks to these characteristics, the watertightness can be improved and made reliable by redundancy.

In embodiments, the two non-return valves comprise at least one ball valve and / or at least one valve with frustoconical bearing, preferably made of metal.

Preferably, the upstream valve is associated with a valve seat of synthetic material, the upstream being defined relative to the direction passing.

In one embodiment, the pilot device comprises an intermediate channel having a first end in communication with the first port on the supply side and a second end in communication with the second port on the supply side, and a piston slidably mounted in the intermediate channel to separate the first end and the second end of the intermediate channel, the piston having an actuating rod configured to cooperate with the first non-return member under the effect of a displacement of the piston in the intermediate channel in response to the control pressure applied at the second port on the power supply side.

Preferably, the piston further has a second actuating rod configured to cooperate with the second non-return member under the effect of a displacement of the piston in the intermediate channel in response to the control pressure applied to the first port side food.

According to embodiments, the volumetric flow divider-combiner and the hydraulic lock may be provided separately or, conversely, may be integrated into a common body having the first power-side port, the second power-side port, and the plurality of parallel ports for connecting the first plurality of control lines to the common body.

In one embodiment, the common body has a central portion substantially housing the hydraulic lock and a wider first longitudinal end portion which houses the volumetric divider-combiner. In one embodiment, the common body has two parallel main faces, the first and second power-side ports of the hydraulic locking device being disposed on one of said main faces at the central portion and said parallel ports of the volumetric divider-combiner being disposed on said main face at the first longitudinal end portion. With this arrangement, access to these different ports is facilitated to make the necessary connections.

In one embodiment, two parallel ports of the volumetric divider-combiner are spaced in a lateral direction of the common body and the first and second power-side ports of the hydraulic lock are spaced in a longitudinal direction of the common body.

Preferably in this case, the branch fitting is also integrated in the common body, the common body further having a plurality of ports associated with branches of the branch fitting for connecting the second plurality of control lines to the common body.

In one embodiment, the common body further comprises a second longitudinal end portion which houses the branch connection.

In one embodiment, the ports associated with branches of the branch connection are disposed on two opposite lateral faces of the second longitudinal end portion.

In one embodiment, the system further comprises a hydraulic distributor connected to the first and second ports on the power supply side of the hydraulic locking device, the hydraulic distributor being switchable to a first, for example direct, supply position in which it communicating the first port on the supply side with a pressure source and the second port on the supply side with a tank at atmospheric pressure, and in a second supply position, for example crossed, in which it communicates the second port on the supply side with the pressure source and the first port on the supply side with the tank at atmospheric pressure. Thanks to these characteristics, the cylinders can be actuated in a rising direction in the first position of the distributor and in a downward direction in the second position of the distributor. Preferably, the hydraulic distributor is further switchable to a neutral position in which it puts in communication the first port on the supply side and the second port on the supply side with the tank at atmospheric pressure. Thanks to these characteristics, the cylinders can be locked in position under the effect of the hydraulic locking device.

In one embodiment, the pressure compensation devices are configured so that the partial rates of each parallel port are equal. Such a configuration is particularly suitable for the synchronous actuation of all cylinders identical.

In one embodiment, the system is configured as a hoist with the jacks configured as lift cylinders. In one embodiment of the lifting system, each jack comprises a jack rod integral with the piston, said jack rod being directed upwards.

The invention also provides a hydraulic lock device having a body having a first power side port, a second power side port, a first load side port, and a second load side port, a first link channel in the body connecting the first power-side port to the first load side port, a first non-return member arranged in the first link channel and having a forward direction from the first power-side port to the first load-side port and a blocking direction from the first load-side port to the first power-side port,

a second link channel in the body connecting the second power-side port to the second load-side port, a second non-return member arranged in the second link channel and having a forward direction from the second power-side port to the second load-side port and a blocking direction from the second port on the load side to the second port on the supply side,

and a pilot device arranged in the body and configured to open the first non-return member in response to a control pressure applied to the second supply side port and to open the second non-return member in response to a control pressure applied to the first port on the power supply side. The invention also provides a common housing incorporating the hydraulic locking device, the divider-combiner and the branch connection.

Brief description of the figures

The invention will be better understood, and other objects, details, characteristics and advantages thereof will appear more clearly in the course of the following description of several particular embodiments of the invention, given solely for illustrative and non-limiting purposes. with reference to the accompanying drawings.

- Figure 1 is a block diagram showing a lifting system according to one embodiment of the invention, in a mounted state.

- Figure 2 is a diagram similar to Figure 1, showing the lifting system in a locked state.

- Figure 3 is a diagram similar to Figure 1, showing the lifting system in a state of descent.

FIG. 4 is a perspective view of a volumetric flow divider-combiner that can be used in the system of FIG. 1.

FIG. 5 is a view of the volumetric flow divider-combiner of FIG. 4 in section along the axis V-V.

FIG. 6 is a functional diagram of a hydraulic locking device that can be used in the system of FIG.

- Figure 7 is a sectional view of the hydraulic locking device of Figure 6, in a locked state.

- Figure 8 is a view similar to Figure 7, showing the hydraulic locking device in an unlocked state.

- Figure 9 is a perspective view of a common housing incorporating the hydraulic locking device and the divider-combiner.

- Figure 10 is a horizontal sectional view of the common housing along the line X-X of Figure 9.

- Figure 11 is a view similar to Figure 9 showing another embodiment. Detailed description of embodiments

Figures 1 to 3 show a hydraulic lifting system 1 in three different operating states. The lifting system 1 here comprises two actuating cylinders A and B, for example supporting a load plate 100 or other equipment to be moved up or down or up and down. The system which will be described below is adaptable to any number of cylinders.

Each of the cylinders A, B comprises a cylinder 2a, 2b in which slides a piston 3a, 3b which separates the interior space of the cylinder into a first chamber, which will be here called lower chamber 4a, 4b, and a second chamber, which will be here called upper chamber 5a, 5b given the orientation of the cylinder. The piston 3a, 3b is integral with a cylinder rod 9a, 9b. In the cylinders A, B, the lower chamber 4a, 4b is called the chamber that must be kept under pressure when the system is locked in the high position, that is to say the chamber that supports the weight of the load to be lifted. Conversely, the upper chamber 5a, 5b designates the chamber which is pressurized for the downward movement and which therefore does not bear the weight of the load to be lifted. The cylinders 2a and 2b are oriented vertically as schematized by the axis z representing the vertical direction, or obliquely along a non-horizontal axis, or even horizontally if there is a force redirecting device (not shown, for example rocking lever ) coupled to the cylinder rod for converting the displacement of the cylinder rod into a displacement having a vertical component.

A hydraulic line 6a, 6b connects the lower chamber 4a, 4b to a volumetric flow divider-combiner 10. A hydraulic line 7a, 7b connects the upper chamber 5a, 5b to a branch connection 20.

The volumetric flow divider-combiner 10 is a bidirectional device which has a common port 11 and two parallel ports 12a and 12b to which the hydraulic lines 6a and 6b are respectively connected. In a divider operation, which corresponds to the operating state of FIG. 1, the total flow rate entering through the common port 11 is divided into two partial flows leaving by the parallel ports 12a and 12b. The volumetric ratio between each partial flow rate and the total flow rate is set independently of the pressure prevailing at the level of parallel port considered, thanks to pressure compensation devices associated with each parallel port, according to the known technique. This volumetric ratio can be fixed, for example 50% at each of the parallel ports 12a and 12b or an unequal or adjustable ratio, depending on the construction of the volumetric flow divider-combiner 10.

In a combiner operation, which corresponds to the operating state of FIG. 3, the two partial flows entering through the parallel ports 12a and 12b are combined into a total output flow through the common port 11 according to the volumetric ratios mentioned above, independently pressure at the parallel ports 12a and 12b.

An exemplary embodiment of the volumetric flow divider-combiner is shown in FIGS. 4 and 5 as 110. The elements similar or identical to those of FIG. 1 are designated by the same reference number increased by 100.

The divider-combiner 110 comprises the common port 111 and the two parallel ports 112a and 112b on two opposite sides of a parallelepipedal metal body 113 hollowed out with multiple channels whose machining holes are closed by plugs 119.

Each parallel port 1 12a, 112b is associated with a check valve 114a, 114b for opening in operation as a divider and a check valve 115a, 115b for opening in operation as a combiner. A slide 116 slidably mounted in the body 113 is subjected to the two pressures at the parallel ports 112a and 112b and performs the flow control by reacting to these pressures.

Returning to FIG. 1, a hydraulic locking device 30 is shown below the volumetric flow divider-combiner 10. The hydraulic locking device 30 has two supply-side ports 31a and 31b and two load-side ports 32a and 32b and two link channels 33a and 33b each connecting a supply side port 31a or 31b to a respective load side port 32a or 32b. A hydraulic line 25 connects the load side port 32a to the common port 1 1 of the volumetric flow divider-combiner 10. A hydraulic line 21 connects the branch connection 20 to the load side port 32b. Each connecting channel 33a, 33b is provided with one or more check valves, which have a forward direction from the power side port to the load side port and a blocking direction from the load side port to the power side port.

A pilot device 35 allows each time to control the opening of the non-return valves of a connecting channel 33a or 33b in response to the application of a sufficiently high opening pressure to the supply side port 31b or 31a from the other link channel. In other words, the application of a sufficiently high opening pressure to the supply-side port 31a causes both the check valve 33a to open at the same time because of the pressure difference positive between the supply side port 31a and the load side port 32a, and the opening of the nonreturn valves of the other connecting channel 33b under the effect of the pilot device 35 due to the positive pressure force difference between the supply side port 31a and the load side port 32b. In this context, the term "sufficiently high opening pressure" therefore means a pressure generating, on the valves, a force greater than the force generated by the pressure at the load side port 32a and load side port 32b.

Conversely, the application of a sufficiently high opening pressure to the supply-side port 31b causes both the non-return valves of the connecting channel 33b to be opened due to the positive pressure force difference between the port on the supply side 31b and the load side port 32b, and the opening of the nonreturn valves of the other connecting channel 33a under the effect of the pilot device 35 due to the positive pressure force difference between the power port port 31b and load side port 32a.

An exemplary embodiment of the hydraulic locking device is shown in Figures 6 to 8 under the number 130. The elements similar or identical to those of Figure 1 are designated by the same reference numeral increased by 100.

The hydraulic locking device 130 comprises an elongate metal body 34, for example cylindrical, having the supply-side ports 131a and 131b drilled laterally. An axial bore 36 passes through the metal body 34 end-to-end and is closed at both ends by two plugs 37 and 38. The plug 38 is pierced with a channel forming the load-side port 132b. The plug 37 is full. A hollow rod 39 is engaged transversely in the metal body 34 between the plug 37 and the supply-side port 131a and has an internal channel which communicates with the bore 36 and whose outer end forms the load-side port 132a.

The pilot device is here a piston 135 arranged sliding in a central portion of the bore 36 and sealingly separating a straight portion of the bore 36 forming the connecting channel 133b of a left portion of the bore 36 forming the link channel 133a. Each connecting channel 133a and 133b successively comprises a frustoconical flap valve 40a, 40b and a ball valve 41a, 41b connected in series between the supply-side port 131a, 131b and the load-side port 132a, 132b and recalled by springs 42a, 43a, 42b, 43b to valve seats formed in a valve body 45a, 45b. The valve bodies 45a, 45b are screwed into the left and right portions of the bore 36.

Preferably, the valve bodies 45a and 45b, the ball valves 41a and 41b and the frustoconical flaps 40a and 40b are metallic. However, vis-à-vis the frustoconical valve 40a, 40b, the valve body 45a, 45b carries a washer 49a, 49b of synthetic material, for example elastomers, forming the valve seat. This arrangement makes it possible to confer different functions on the two valves: the ball valve 41a or 41b is located on the load side and can withstand water hammers and receive more impurities in operation. It is made for this in a more robust material. The frustoconical flap valve 40a or 40b located on the supply side is more protected and is made with a higher level of sealing, thanks to the valve seat made of synthetic material, but possibly lower strength.

The non-return valves, namely ball valves 41a and 41b and frustoconical flap valves 40a and 40b, are in each case passing in the direction from the supply-side port 131a, 131b to the load-side port 132a, 132b, that is, open spontaneously in response to a negative pressure gradient in that direction.

The operation of the pilot device constituted by the piston 135 will now be explained with reference to FIGS. 7 and 8. In FIG. 7, the piston 135 is shown in the neutral position in the absence of a pressure differential between the ports on the supply side 131 a and 131 b. It does not interact with any flappers. In Fig. 8, a sufficiently high opening pressure is applied to the power-side port 131b. In this context, the term "sufficiently high opening pressure" therefore means a pressure generating a force greater than the force caused by the pressure at the load side port 132b and the load side port 132a. The piston 135 is thus pushed towards the connecting channel 133a in response to the differential pressure force. A rod 46a carried by the piston 135 then pushes the frustoconical valve 40a in the open position. Simultaneously, a rod 47a carried by the frustoconical flap valve 40a also pushes the ball valve 41a open, even if the pressure force at the load side port 132a is higher than the supply side port 131a.

The operation is symmetrical when a sufficiently high opening pressure is applied to the supply side port 131a.

Returning to FIG. 1, the operation of the hoisting system in a climbing movement will now be described. To cause the upward movement of the cylinders A and B, the supply side port 31a is connected to a source of pressure while the supply side port 31b is connected to a tank at atmospheric pressure. The flow of liquid, for example a hydraulic oil, supplied by the pressure source passes through the left branch (channel 33a) of the hydraulic locking device 30, in the hydraulic line 25 and is divided into two flow rates in the hydraulic lines 6a. and 6b according to the volumetric ratios fixed by the divider-combiner 10, namely 50% and 50% in the case of two identical cylinders to be actuated synchronously in equal proportions.

The influx of liquid with a rigorously equal flow rate in the lower chambers 4a and 4b of the two cylinders A and B causes a synchronized displacement of the two pistons 3a and 3b, indicated by the arrows 18. The level of precision of the divider-combiner 10 is typically 1 to 2%, which is quite acceptable for a typical lifting application.

Simultaneously, the liquid expelled from the upper chambers 5a and 5b refluxed by the hydraulic lines 7a and 7b, is joined at the branch connection 20 and flows through the hydraulic line 21 and the right branch (channel 33b) of the device. hydraulic lock 30 to the supply side port 31b, from where it can reach the tank. Figure 2 shows the lifting system 1 in a locked state, in which the two power-side ports 31a and 31b are connected to the atmospheric pressure. In this state, the position of the cylinders A and B is maintained by the action of the check valves of the left branch (channel 33a) of the hydraulic locking device 30, which prevents the liquid from refluxing under the effect of the load applied to the cylinder rods 9a and 9b, symbolized by the arrow 19.

If there is a leak in the hydraulic locking device 30, as symbolized by the leakage rate 26 in Figure 2, a slight uncontrolled downward movement of the cylinders A and B can be observed, especially over a long period of time. . However, thanks to the partial flow compensation imposed by the divider-combiner 10, the cylinders A and B remain synchronized even during this uncontrolled descent. The situation would be different if there was a separate hydraulic locking device for each cylinder, which is here expressly avoided.

Figure 3 shows the lifting system 1 in a state of descent.

To cause the downward movement of the cylinders A and B, the supply side port 31b is connected to the pressure source while the supply side port 31a is connected to the atmospheric pressure tank. The flow of liquid supplied by the pressure source passes through the right branch (channel 33b) of the hydraulic locking device 30, in the hydraulic line 21 and is divided by the branch connection 20 in the hydraulic lines 7a and 7b to the high rooms 5a and 5b. Simultaneously, the liquid expelled from the lower chambers 4a and 4b refluxed by the hydraulic lines 7a and 7b, is combined at the level of the divider-combiner 10 according to the fixed volumetric ratios and flows through the hydraulic line 25 and the branch on the left ( channel 33a) of the hydraulic locking device 30 to the supply side port 31a, where it can join the tank.

It will be noted that, in the absence of a leakage rate at the pistons 3a and 3b, the control of the outflows of the lower chambers 4a and 4b by the divider-combiner 10 simultaneously imposes an equivalent distribution of the flow rates entering the upper chambers 5a. and 5b. The descent movement of the two cylinders remains well synchronized. In order to supply the lifting system 1 with hydraulic pressure in the various operating states, the hydraulic distributor 50 shown in FIGS. 1 to 3 can be used.

On the source side, the hydraulic distributor 50 is connected to a pump 51 and to a tank of liquid at atmospheric pressure 52, or tank. On the distribution side, the hydraulic distributor 50 is connected to the ports on the supply side 31a and 31b. In the direct switching state shown in FIG. 1, the hydraulic distributor 50 places the supply-side port 31a in communication with the pump 51 and the supply-side port 31b with the atmospheric pressure tank 52. In the crossed switching state shown in FIG. 3, the hydraulic distributor 50 puts the supply side port 31b in communication with the pump 51 and the supply side port 31a with the atmospheric pressure tank 52.

In the neutral switching state shown in FIG. 3, the hydraulic distributor 50 puts the supply side port 31a and the supply side port 31b in communication with the atmospheric pressure tank 52.

As illustrated, oil filters 55 may be provided at different locations of the circuit to prevent pollution of the mechanical components by impurities and dust, especially at the inlet of the supply side ports 31a and 31b and on the hydraulic lines 6a, 6b and 25.

As described above, the hydraulic lock 30 and the divider-combiner 10 can be made separately. As sketched in Figures 1 to 3, a common housing 60 incorporating these two components can also be realized, for compactness. In this case, the common body comprises the ports 31a, 31b, 12a and 12b, and two ports 17a and 17b associated with the two branches of the branch connection 20 for connecting the hydraulic lines 7a and 7b.

Figures 9 and 10 illustrate an embodiment of the common housing incorporating the hydraulic locking device, the divider-combiner and the branch connection and designed to drive two cylinders. Elements similar or identical to those of Figure 1 are designated by the same reference numeral increased by 200.

In the common housing 260 are integrated a hydraulic locking device 230, a volumetric divider-combiner 210 and a coupling of 220. The common housing can have different shapes. The common housing 260 shown in Figure 9 has an advantageous compactness. It consists of a flattened body having two parallel main faces, of which only the upper face 61 is visible. The thickness is for example between 50 and 100 mm. This body has a central portion 63 in the form of narrow bar with rectangular section and two end portions 64 and 65 arranged on either side of the central portion 63 in the longitudinal direction.

The central portion 63 essentially houses the hydraulic locking device 230, which is constructed similarly to the hydraulic locking device 130 described above. The two power-side ports 231a and 231b of the hydraulic locking device 230 are disposed on the upper face 61 at the central portion 63 and spaced in the longitudinal direction.

The end portion 64 is the widest and houses the volumetric divider-combiner 210. The two parallel ports 212a and 212b of the volumetric divider-combiner 210 are disposed on the upper face 61 at the end portion 64 and spaced apart. in the lateral direction.

The end portion 65 has an intermediate width and houses the branch connection 220. The two ports 217a and 217b associated with the two branches of the branch connection 220 are disposed on two opposite lateral faces 66 and 67 of the end portion 65 and spaced in the lateral direction.

Multiple machining holes are closed by plugs 219.

The lifting system 1 described above can easily be adapted to any number of actuators actuated simultaneously. For this, a first option is to modify the number of parallel ports 12 of the divider-combiner 10. A second option, especially when the number of actuators to be actuated is an integer power of the number 2, is to mount in series several stages of dividers combiners 10 having two parallel ports 12 each. These two options can also be combined, especially when the number of actuators to be actuated is an integer power of an integer greater than 2. In all cases, the number of branches of the branch connection 20 can be adapted to the total number of actuators. actuating cylinders.

Thus, FIG. 11 illustrates a common housing 360 incorporating the hydraulic locking device, the divider-combiner and the bypass connection and designed to drive four cylinders. The structure is the same as that of the common housing 260 described above, except:

- The number of branches of the branch connection which is increased to four, which are associated with the ports 317a to 317d (not visible). the number of branches of the divider-combiner which is increased to four, with which the parallel ports 312a to 312d are associated.

Finally, other hydraulic actuation and displacement systems can be manufactured according to the same principles, in other applications than lifting, for example to move horizontally mechanical elements such as doors, drawers, tools, etc. In all cases, the use of a single hydraulic locking device pooled for all cylinders is a factor in reducing the cost of acquisition of the system.

The use of the verb "to include", "to understand" or "to include" and its conjugated forms does not exclude the presence of other elements or steps other than those set out in a claim.

In the claims, any reference sign in parentheses can not be interpreted as a limitation of the claim.

Claims

Hydraulically operated actuating system (1) comprising:

a plurality of jacks (A, B) to be synchronously actuated, each jack having a cylinder (2a, 2b) having an interior space and a piston (3a, 3b) dividing the interior of the cylinder into a first chamber (4a, 4b) and a second chamber (5a, 5b), the piston being movable in the cylinder in a displacement stroke,

a flow divider-combiner having a common port (11) and a plurality of parallel ports (12a, 12b),

a first plurality of control lines (6a, 6b) each connecting a respective parallel port of the flow divider-combiner to the first chamber of a respective cylinder (A, B),

a branch connection (20) with several branches,

a second plurality of control lines (7a, 7b) each connecting a respective branch of the branch fitting (20) to the second chamber (5a, 5b) of a respective jack, and

a hydraulic locking device (30) having a first supply side port (31a) for connection to a pressure source, a second supply side port (31b), a first connection channel (33a) connecting the first side port supply to the common port (11) of the flow divider-combiner, a first non-return member arranged in the first link channel and having a forward direction from the first power-side port to the common port of the flow divider-combiner and a blocking direction from the common port of the divider-flow combiner to the first port on the supply side, and a pilot device (35) configured to open the first non-return member in response to a control pressure applied to the second port on the supply side (31b )

the hydraulic locking device (30) further comprising a second connecting channel (33b) connecting the second supply side port (31b) to the branch connection (20), a second non-return member arranged in the second connecting channel and having a forward direction from the second power-side port to the bypass fitting and a blocking direction from the bypass connection to the second power-side port, wherein the pilot device is configured to open the second anti-return member in response to a pressure of command applied to the first port on the supply side (31 a)

and wherein the flow divider-combiner is a volumetric flow divider-combiner (10, 210) configured for, in a divider operation, divide a total incoming flow rate by the common port into a plurality of partial throughput rates through the parallel ports and, in a combiner operation, combining a plurality of partial flows entering through the parallel ports into a total outflow through the common port, the volumetric flow divider-combiner (10, 210) having a pressure compensation device associated with each parallel port for setting the volumetric ratio between the partial flow of the parallel port and the total flow rate independently of an operating pressure of said parallel port.

2. System according to claim 1, wherein at least one of the first non-return member and the second non-return member comprises two non-return valves (40a, 41a, 40b, 41b) arranged in series in the connecting channel (33a, 33b).

3. System according to claim 2, wherein the two check valves (40a, 41a, 40b, 41b) arranged in series are different from each other as to the geometry and / or the material.

4. System according to any one of claims 2 to 3, wherein the two check valves comprise at least one ball valve (41a, 41b) and / or at least one frustoconical flap (40a, 40b ), preferably of metal.

5. System according to any one of claims 2 to 4, wherein the upstream check valve is associated with a valve seat of synthetic material, the upstream being defined relative to the direction.

The system of any one of claims 1 to 5, wherein the pilot device (35,235) includes an intermediate channel (36) having a first end in communication with the first power-side port (131a, 231a). and a second end in communication with the second supply side port (131b, 231b), and a piston (135) slidably mounted in the intermediate channel to separate the first end and the second end of the intermediate channel, the piston having a rod actuator (46a) configured to cooperate with the first non-return member (40a, 41a) by moving the piston in the intermediate channel in response to the control pressure applied to the second power-side port ( 131 b, 231 b).

7. System according to claim 6, wherein the piston (135) further has a second actuating rod (46b) configured to cooperate with the second non-return member (40b, 41b) under the effect of a displacement piston in the intermediate channel in response to the control pressure applied to the first supply side port (131a, 231a).

The system of any one of claims 1 to 7, further comprising a hydraulic distributor (50) connected to the first and second power-side ports (31a, 31b) of the hydraulic lock (30, 230), the hydraulic distributor being switchable in a first supply position in which it places the first supply-side port in communication with a pressure source (51) and the second supply-side port with an atmospheric pressure tank (52), and in a second feeding position in which it communicates the second port on the supply side with the pressure source and the first port on the supply side with the tank at atmospheric pressure.

9. System according to claim 8, wherein the hydraulic distributor (50) is further switchable to a neutral position in which it puts in communication the first port on the supply side and the second port on the supply side with the tank at atmospheric pressure.

The system of any one of claims 1 to 9, wherein the pressure compensation devices (116) are configured such that the partial flow rates of each parallel port (12a, 12b; 212a, 212b) are equal.

The system of any one of claims 1 to 9, wherein the pressure compensation devices (116) are configured such that the partial flow rates of each parallel port (12a, 12b; 212a, 212b) are unequal.

12. System according to any one of claims 1 to 1 1, configured as a lifting system, the cylinders being configured as lifting cylinders.

13. The system of claim 12, wherein each jack comprises a cylinder rod (9a, 9b) integral with the piston (3a, 3b), said cylinder rod

(9a, 9b) being upwardly oriented.

System according to any one of claims 1 to 13, wherein the volumetric flow divider-combiner (10, 210) and the hydraulic locking device (30, 230) are integrated in a common body (60, 260). having the first power-side port (31a, 231a), the second power-side port (31b, 231b) and the plurality of parallel ports (12a, 12b; 212a, 212b) for connecting the first plurality of control lines (6a, 6b) to the body

The system of claim 14, wherein the bypass fitting (20, 220) is also integrated into the common body (60, 260), the common body further having a plurality of ports (17a, 17b; 217a, 217b). ) associated with branches of the branch fitting for connecting the second plurality of control lines (7a, 7b) to the common body.

The system of any one of claims 14 to 15, wherein the common body (260) has a central portion (63) substantially housing the hydraulic lock (230) and a first longitudinal end portion (64). wider which houses the volumetric divider-combiner (210).

The system of claim 16, wherein the common body has two parallel major faces, the first and second power-side ports (231a, 231b) of the hydraulic lock (230) being disposed on a said major face (61). ) at the central portion (63) and said parallel ports (212a, 212b) of the volumetric divider-combiner (210) being disposed on said main face (61) at the first longitudinal end portion (64).

The system of claim 17, wherein two parallel ports (212a, 212b) of the volumetric divider-combiner (210) are spaced in a lateral direction of the common body (260) and the first and second power-side ports (231 a, 231 b) of the hydraulic lock (230) are spaced in a longitudinal direction of the common body (260).

The system of any one of claims 16 to 18, wherein the common body (260) further includes a second longitudinal end portion (65) which houses the branch fitting (220).

The system of claim 19, wherein the ports (217a,

217b) associated with branches of the branch fitting (220) are disposed on two opposite side faces (66, 67) of the second longitudinal end portion (65).