FR3056266A1 - HYDRAULICALLY CONTROLLED SYSTEM - Google Patents

Abstract

The invention relates to a hydraulically operated system (1) comprising a plurality of jacks (A, B) for synchronized actuation, each cylinder having a cylinder having an interior space and a piston (3a, 3b) dividing the cylinder internal space of the cylinder in a first chamber (4a, 4b) and a second chamber (5a, 5b), a volumetric flow divider-combiner (10) having a common port and a plurality of parallel ports (12a, 12b), a plurality of control lines (6a, 6b) each connecting a respective parallel port to the first chamber of a respective jack, and a hydraulic lock device (30) having a first supply side port (31a) for connection to a respective a source of pressure, a connecting channel connecting the first port on the supply side to the common port (11), and a non-return device arranged in the connection channel and having a forward direction from the first port on the supply side; towards the common port.

Description

Technical area

The invention relates to the field of actuator systems intended to be actuated synchronously, in particular to 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 car platforms. When a loaded platform or structure must be lifted by several jacks while keeping a given orientation, for example horizontal, It is important that Its jacks are actuated in a synchronized manner whatever the load they support, including if this load n is not evenly distributed on His jacks. Otherwise, synchronization faults are likely to lead to jamming or damage to the lifting system.

summary

A basic idea of the invention is to provide a hydraulically controlled system in which the actuation of several cylinders can be synchronized and in which the cylinders 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 for several jacks which can maintain good synchronization even in the event of a leak in the hydraulic locking device. Another object of the invention is to obtain a device for controlling several jacks which employs a single locking device.

According to one embodiment, the invention provides an actuation system, for example a lifting system, with hydraulic control comprising:

a plurality of cylinders intended to be actuated synchronously, each cylinder comprising a cylinder having an interior space and a piston dividing the interior space of the cylinder into a first chamber and a second chamber, the piston being movable in the cylinder according to a stroke displacement, a volumetric flow divider-combiner having a common port and a plurality of parallel ports, the volumetric flow divider-combiner being configured to, in divider operation, dividing a total incoming flow through the common port into a plurality of partial flows leaving through parallel ports and, in combinatorial operation, combining a plurality of partial flows entering through parallel ports into a total flow leaving through the common port, the volumetric flow divider-combiner comprising an associated pressure compensation device to each parallel port to fix the rappor t volumetric between the partial flow of the parallel port and the total flow 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 comprising a first port on the supply side intended to be connected to a pressure source, a second port on the supply side, a connecting channel connecting the first port on the supply side to the common port of the flow divider-combiner volumetric, a non-return device arranged in the connecting channel and having a direction passing from the first port on the supply side to the common port of the volumetric flow divider-combiner and a blocking direction from the common port of the volumetric flow divider-combiner to the first port on the power supply side, and a trusted pilot device curved to open the non-return device in response to a control pressure applied to the second supply side port.

Thanks to these characteristics, the jacks can be actuated to actuation positions by applying pressure to the first port on the supply side of the hydraulic locking device. Thanks to the volumetric flow divider-combiner, the different cylinders are actuated in well-controlled proportions, equal or not, according to the fixed volumetric ratios. In addition, the cylinders can be locked in an actuating position using the hydraulic locking device and its non-return member when the pressure applied to the first port 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.

According to advantageous embodiments, such a device can 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 connection with several branches and a second plurality of control lines each connecting a respective branch of the branch connection to the second chamber of a respective cylinder. Thanks to these characteristics, the second chambers of all the cylinders can be economically and simply connected to a high or low pressure source, via the bypass 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 member arranged in the second connection channel and having a direction passing from the second port on the supply side to the branch connection and a blocking direction from the branch connection to the second port on the supply side, in which the pilot device is configured to open the second non-return member in response to a control pressure applied to the first port on the supply side. Thanks to these characteristics, the hydraulic flows entering and leaving 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 regards the geometry and / or the material. Thanks to these characteristics, sealing can be improved and made more 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 valve located upstream is associated with a valve seat in synthetic material, the upstream being defined with respect to the passing direction.

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 mounted to slide in the intermediate channel to separate the first end and 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 its applied control pressure at the second port on the power supply side.

Preferably, the piston also 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 side port. food.

According to embodiments, the volumetric flow divider-combiner and the hydraulic locking device can be supplied separately or, conversely, can be integrated into a common body having the first port on the supply side, the second port on the supply side and the plurality of parallel ports for connecting the first plurality of control lines to the common body.

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

In one embodiment, the system further comprises a hydraulic distributor connected to the first and second ports on the supply side of the hydraulic locking device, the hydraulic distributor being switchable in a first supply position, for example direct, in which it activates communicates the first supply side port with a pressure source and the second supply side port with an atmospheric pressure tank, and in a second supply position, for example crossed, in which it puts the second supply side port in communication with the pressure source and the first supply side port with the atmospheric pressure tank. Thanks to these characteristics, the jacks can be actuated in an upward 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 also switchable in a neutral position in which it puts the first port on the supply side and the second port on the supply side in communication with the atmospheric pressure tank. Thanks to these characteristics, the jacks 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 flow rates of each parallel port are equal. Such a configuration is particularly suitable for the synchronous actuation of all identical cylinders.

In one embodiment, the system is configured as a lifting system, the jacks being configured as lifting jacks.

The invention also provides a hydraulic locking device comprising a body having a first port on the supply side, a second port on the supply side, a first port on the load side, and a second port on the load side, a first connection channel in the body connecting the first supply side port to the first load side port, a first non-return member arranged in the first connection channel and having a direction passing from Se first supply side port to the first load side port and a blocking direction from Se first load side port to the first port on the supply side, a second connection channel in the body connecting the second port on the supply side to the second port on the load side, a second non-return member arranged in the second connection channel and having a direction passing from the second port on the supply side to the second load side port and a blocking direction from the second port t load side to the second supply side port, 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 port on the supply side and to open the second non-return member in response to a control pressure applied to the first supply side port.

Brief description of the figures

The invention will be better understood, and other objects, details, characteristics and advantages thereof will appear more clearly during the following description of several particular embodiments of the invention, given solely by way of illustration and without limitation. , with reference to the accompanying drawings.

- Figure 1 is a functional 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 lowering state.

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

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

- Figure 6 is a functional diagram of a hydraulic locking device that can be used in the system of Sa Figure 1.

- 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.

Detailed description of embodiments

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

Each of the jacks 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 here be called the lower chamber 4a, 4b, and a second chamber, which will be here called upper chamber 5a, 5b taking into account the orientation of the jack. The piston 3a, 3b is integral with a cylinder rod 9a, 9b. In the cylinders A, B, the lower chamber 4a, 4b is the chamber which must be kept under pressure when the system is locked in the upper position, that is to say the chamber which 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 support the weight of the load to be lifted. The cylinders 2a and 2b are oriented vertically as shown diagrammatically by the axis z representing the vertical direction, or obliquely along a non-horizontal axis, or even horizontally if there is a force return device (not shown, for example rocking lever ) coupled to the cylinder rod to convert 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 sign 7a, 7b connects the upper chamber 5a, 5b to a branch connection 20.

The volumetric flow divider-combiner 10 is a bidirectional device which comprises a common port 11 and two parallel ports 12a and 12b to which the hydraulic lines 6a and 6b are connected respectively. In a divider operation, which corresponds to the operating state of FIG. 1, the total flow entering by the common port 11 is divided into two partial flows leaving by your parallel ports 12a and 12b. The volumetric ratio between each partial flow and the total flow is fixed independently of the pressure prevailing at the parallel port considered, by means of 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 adjustable, depending on the construction of the volumetric flow divider-combiner 10.

In combinatorial operation, which corresponds to the operating state of FIG. 3, the two partial bit rates entering through the parallel ports 12a and 12b are combined into a total bit rate coming out through the common port 11 according to the volumetric ratios mentioned previously, independently of the pressure prevailing at the parallel ports 12a and 12b.

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

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

Each parallel port 112a, 112b is associated with a non-return valve 114a, 114b intended to open in operation as a divider and a non-return valve 115a, 115b intended to open in operation as a combiner. A drawer 116 slidably mounted in the body 113 is subjected to the two pressures prevailing at the parallel ports 112a and 112b and realizes the adjustment of the flow rates 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 ports on the supply side 31a and 31b and two ports on the load side 32a and 32b, as well as two link channels 33a and 33b each connecting a port on the supply side 31a or 31b to a port on the respective load side 32a or 32b. A hydraulic line 25 connects the load side port 32a to the common port 11 of the volumetric flow divider-combiner 10. A hydraulic line 21 connects the bypass fitting 20 to the load side port 32b.

Each link channel 33a, 33b is provided with one or more non-return valves, which have a direction passing from the port on the supply side to the port on the load side and a blocking direction from the port on the load side to the port on the supply side.

A pilot device 35 makes it possible each time to control the opening of the non-return valves of a connection channel 33a or 33b in response to the application of a high pressure to the port on the supply side 31b or 31a of the other channel. link. In other words, the application of a high pressure to the port on the supply side 31a causes both the opening of the non-return valves of the connecting channel 33a due to the positive pressure difference between the port on the supply side 31a and the load side port 32a, and the opening of the non-return valves of the other connecting channel 33b under the effect of the pilot device 35 due to the positive pressure difference between the supply side port 31a and the power side port 31b. In this context, the expression "high pressure" therefore means a pressure greater than its pressure prevailing at the load side port 32a and at the supply side port 31b.

Conversely, applying high pressure to the supply side port

31b causes ia both the opening of the non-return valves of the connecting channel 33b due to the positive pressure difference between the port on the supply side 31b and Se port on the load side 32b, and the opening of the non-return valves of the other connecting channel 33a under the effect of the pilot device 35 due to the positive pressure difference between Se port supply side 31 b and the port supply side 31a.

An exemplary embodiment of the hydraulic locking device is shown in FIGS. 6 to 8 under the number 130. Elements similar or identical to those of FIG. 1 are designated by the same reference number increased by 100.

The hydraulic locking device 130 comprises an elongated metal body, for example cylindrical, having the supply side ports 131a and 131b pierced laterally. An axial bore 36 passes through the metal body 34 from 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 port on the supply side 131a and has an internal channel which communicates with the bore 36 and the external end of which forms the port on the load side 132a.

The pilot device here is 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 from a left portion of the bore 36 forming the connecting channel 133a. Each connecting channel 133a and 133b successively comprises a valve with a frustoconical bearing 40a, 40b and a ball valve 41a,

41b mounted in series between the supply side port 131a, 131b and the load side port 132a, 132b and returned by springs 42a, 43a, 42b, 43b to valve seats formed in a valve body 45a, 45b. The valve bodies 45a, 45b are fixed by screwing in the left and right portions of the bore 36.

Preferably, the valve bodies 45a and 45b, the ball valves 41a and 41b and the frusto-conical valves 40a and 40b are metallic. However, opposite the valve with a frustoconical bearing 40a, 40b, the valve body 45a, 45b carries a washer 49a, 49b made 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 hammer and receive more impurities in operation. It is made for this in a more robust material. The valve with a frustoconical bearing 40a or 40b located on the supply side is more protected and is produced with a higher level of tightness, thanks to the valve seat in synthetic material, but possibly less robustness.

The non-return valves, namely ball valves 41a and 41b and frusto-conical valves 40a and 40b, are each passing in the direction from the port on the supply side 131a, 131b towards the port on the load side 132a, 132b, c ' i.e. open spontaneously in response to a negative pressure gradient in this direction.

The operation of the pilot device consisting of 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 131a and 131b. It then does not interact with any valve.

In Figure 8, high pressure is applied to the supply side port

131b. In this context, the expression "high pressure" therefore means a pressure higher than the pressure prevailing at the load side port 132b and at the supply side port 131a. The piston 135 is therefore pushed towards the connecting channel 133a in response to the pressure differential. A rod 46a carried by the piston 135 then pushes the valve with frustoconical bearing 40a in the open position. Simultaneously, a rod 47a carried by the frustoconical bearing valve 40a also pushes the ball valve

41a in the open position, even if the pressure at the load side port 132a is higher than at the supply side port 131a.

Operation is symmetrical when high pressure is applied to the supply side port 131a.

Returning to FIG. 1, the operation of the lifting system in an upward movement will now be described. To cause the upward movement of the cylinders A and B, Se on the supply side 31a is connected to a pressure source while the port on the supply side 31b is connected to an atmospheric pressure tank. 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 flows in its hydraulic lines 6a and 6b according to its volumetric ratios fixed by the divider-combiner 10, namely 50% and 50% in the case of two identical jacks to be actuated in a synchronized manner.

The inflow of liquid with a strictly 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 generally 1 to 2%, which is perfectly acceptable for a typical lifting application.

Simultaneously, the liquid expelled from the upper chambers 5a and 5b flowed back by the hydraulic signs 7a and 7b, is gathered at the level of the bypass fitting 20 and flows through the hydraulic sign 21 and the right branch (channel 33b) of the device. hydraulic locking 30 to the supply side port 31 b, from where it can reach the tank.

The passage of the liquid in the hydraulic locking device 30 between the upper chambers 5a and 5b and the reservoir is not essential since its upper chambers 5a and 5b never support the load in a lifting system. In a variant not shown, a separate circuit is used for this connection.

Figure 2 shows the lifting system 1 in a locked state, in which the two supply side ports 31a and 31b are connected to atmospheric pressure. In this state, the position of the cylinders A and B is maintained by the action of the non-return valves of the left branch (channel 33a) of the hydraulic locking device 30, which prevents the liquid from flowing back 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 FIG. 2, a slight uncontrolled movement of descent of the cylinders A and B can be observed, in particular over a long period . However, thanks to the repair of the partial flow rates imposed by the divider-combiner 10, its jacks 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 of the cylinders, which is here expressly avoided.

Figure 3 shows the lifting system 1 in a lowering state.

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 connector 20 in the hydraulic lines 7a and 7b towards the , upper chambers 5a and 5b. Simultaneously, the liquid expelled from the lower chambers 4a and 4b flowed back by the hydraulic signs 7a and 7b, is combined at the level of the divider-combiner 10 according to the fixed volumetric ratios and flows through its hydraulic line 25 and the left branch ( channel 33a) of the hydraulic locking device 30 to the supply side port 31a, from where it can join the reservoir.

It will be noted that, in the absence of leakage flow at the pistons 3a and 3b, the control of the flows leaving the low chambers 4a and 4b by the divider-combiner 10 simultaneously imposes an equivalent distribution of the flows entering its high chambers 5a and 5b . The lowering movement of the two cylinders remains well synchronized.

To supply the lifting system 1 with hydraulic pressure in the different operating states, the hydraulic distributor 50 shown in Figures 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 tarpaulin. On the distribution side, the hydraulic distributor 50 is connected to the supply side ports 31a and 31b. In the direct switching state shown in FIG. 1, the hydraulic distributor 50 communicates the supply side port 31a 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 places 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 places the supply side port 31a and the supply side port 31b in communication with the atmospheric pressure tank 52.

As illustrated, oil filters 55 can be provided at different locations of the circuit to avoid pollution of the mechanical components by impurities and dust, in particular 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 locking device 30 and the divider-combiner 10 can be produced separately. As sketched in FIGS. 1 to 3, a common box 60 integrating these two components can also be made, for compactness. In this case, the common body comprises the ports 31a, 31b, 12a and 12b, as well as two ports 17a and 17b associated with the two branches of the branch connection 20 for connecting the hydraulic lines 7a and 7b.

The lifting system 1 described above can be easily 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, in particular when the number of jacks to be actuated is a whole power of the number 2, is to mount in series several stages of dividers25 combiners 10 having two parallel ports 12 each. These two options can also be combined, in particular when the number of jacks 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.

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

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

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

Claims (5)

1. Hydraulic actuation system (1) comprising: a plurality of cylinders (A, B) intended to be actuated synchronously, each cylinder comprising a cylinder (2a, 2b) having an interior space and a piston (3a, 3b) dividing the interior space of the cylinder into a first bedroom (4a, 4b) and a second chamber (5a, 5b), the piston being movable in the cylinder according to a displacement stroke, a volumetric flow divider-combiner (10, 110) having a port 10 common (11) and a plurality of parallel ports (12a, 12b), the volumetric flow divider-combiner being configured to, in divider operation, divide a total flow entering by the common port into a plurality of partial flows leaving by Its parallel ports and, in a combinatorial operation, combine a plurality of partial flows entering through the parallel ports into a total outgoing flow 15 by the common port, the volumetric flow divider-combiner comprising a pressure compensation device associated with each parallel port to fix the volumetric ratio between the partial flow of the parallel port and Se total flow independently of an operating pressure of said port parallel, a plurality of control lines (6a, 6b) each connecting a parallel port 20 respective of the volumetric flow divider-combiner to the first chamber of a respective jack (A, B), and a hydraulic locking device (30) comprising a first port on the supply side (31a) intended to be connected to a source of pressure, a second supply side port (31b), a connecting channel (33a) connecting the first side port 25 supply to the common port (11) of the volumetric flow divider-combiner (10), a non-return member arranged in the connection channel and having a direction passing from the first port on the supply side to the common port of the volumetric flow divider and combiner and a blocking direction from the common port of the volumetric flow divider-combiner to the first port on the supply side, and 30 a pilot device (35) configured to open the non-return member in response to a control pressure applied to the second supply side port (31b). 2. The system as claimed in claim 1, in which the plurality of control signs (6a, 6b) is a first number of control lines, the i system further comprising a branch connection (20) with several branches and a second plurality of control lines (7a, 7b) each connecting a respective branch of the branch connection (20) to the second chamber (5a, 5b) of a respective cylinder. 5 3. The system of claim 2, wherein the connecting channel and the non-return member of the hydraulic locking device are a first connecting channel (33a) and a first non-return member, Se hydraulic locking device (30 ) further comprising a second connecting channel (33b) connecting the second supply side port (31b) to the bypass fitting (20), a second 10 non-return member arranged in the second connection channel and having a direction passing from the second port on the supply side towards the branch connection and a blocking direction from the branch connection towards the second port on the supply side, in which the pilot device is configured to open Se second check member in response to control pressure applied to the first 15 power supply port (31A). 4. System according to any one of claims 1 to 3, in which 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 Se connecting channel (33a, 33b). 5. System according to claim 4, in which the two non-return valves (40a, 41a; 40b, 41b) arranged in series are different from each other as regards the geometry and / or the material. 6. System according to any one of claims 4 to 5, in which the two non-return valves comprise at least one ball valve (41a, 41b) 25 and / or at least one valve with frustoconical bearing (40a, 40b), preferably made of metal. 7. System according to any one of claims 4 to 6, in which the non-return valve located upstream is associated with a valve seat in synthetic material, the upstream being defined relative to the passing direction. 8. System according to any one of claims 1 to 7, in which the pilot device (35) comprises an intermediate channel (36) having a first end in communication with the first port on the supply side (131a) and a second end in communication with the second supply side port (131b), and a piston (135) slidably mounted in the intermediate channel to separate the first end and the second end of the intermediate channel, piston having an actuating rod (46a) configured to cooperate with the first non-return member (40a, 41a) under the effect of a displacement of the piston in the intermediate channel in response to the control pressure applied to the second port on the supply side (131b). 9. The system of claim 8 taken in combination with claim 3, 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 of the piston in the intermediate channel in response to the control pressure applied to the first port on the supply side (131a). 10. System according to any one of claims 1 to 9, in which the volumetric flow divider-combiner (10) and the hydraulic locking device (30) are integrated in a common body (60) having the first port on the supply side. (31a), the second supply side port (31b) and the plurality of parallel ports (12a, 12b) for connecting the first plurality of control lines (6a, 6b) to the common body (60). 11. The system of claim 10 taken in combination with claim 3, wherein the bypass fitting (20) is also integrated in the common body (60), the common body further having a plurality of ports (17a, 17b) associated with branches of the bypass connector for connecting the second plurality of control lines (7a, 7b) to the common body. 12. The system of claim 3, further comprising a hydraulic distributor (50) connected to the first and second supply side ports (31a, 31b) of the hydraulic locking device (30), the hydraulic distributor being switchable in a first position of supply in which it communicates the first port on the supply side with a pressure source (51) and the second port on the supply side with an atmospheric pressure tank (52), and in a second supply position in which it puts in communication the second supply side port with the pressure source and the first supply side port with the atmospheric pressure tank. 13. System according to claim 12, in which the hydraulic distributor (50) is also switchable in a neutral position in which it puts the first port on the supply side and the second port on the supply side into communication with the atmospheric pressure tank. 5 14. System according to any one of claims 1 to 13, wherein the pressure compensation devices (116) are configured so that the partial flow rates of each parallel port (12a, 12b) are equal. 15. System according to any one of claims 1 to 14, configured as a lifting system, its jacks being configured as jacks of 10 lifting.