FR3055375A1 - HYDRAULIC CONTROL CIRCUIT - Google Patents

Abstract

Multi-control hydraulic circuit formed by the assembly of hydraulic modules each associated with a receiver and having a spool valve (Di) combined with a pressure compensator (CPi) with a pump line (P), a return line ( T) and a control line (LS) controlling the pump (1) by a control pressure depending on the operation of the receivers, the bore (A1) of the distributors having a pair of orifices (EO, SO) connected to the line neutral (LO) of the module and the drawer (T1) of the distributor has a passage (PO) which, in the neutral position of the drawer, connects the orifices (EO, SO).

Description

(74) MULTIPLE CONTROL HYDRAULIC CIRCUIT.

©) Multiple control hydraulic circuit formed by the assembly of hydraulic modules each associated with a receiver and having a slide valve (Di) combined with a pressure compensator (CPi) with a pump line (P), a line of return (T) and a control line (LS) controlling the pump (1) by a control pressure depending on the operation of the receivers, the bore (A1) of the distributors having a pair of orifices (EO, SO) connected to the neutral line (LOi) of the module and the drawer (T1) of the distributor has a passage (PO) which, in the neutral position of the drawer, connects the orifices (EO, SO).

100 / 1-,

i

Field of the invention

The present invention relates to a multiple control hydraulic circuit formed by the assembly of hydraulic modules each associated with a receiver to activate it in a controlled manner via a slide valve (Di) combined with a compensator of pressure (CPi) and having:

a pump line (P) connecting the controlled pump (P) to the input of the module supply (Mi), a return line (T) connecting the output of the receivers (Ri) to the tank (2) of the pump (1), a control line (LS) controlling the pump (1) by a control pressure depending on the operation of the receivers (Ri), each distributor (Di) having a drawer with:

• a pair of orifices (E0, S0) connected to the neutral line (LO) of the module (Mi), • a pair of orifices (El, SI) whose orifice (El) is connected to the pump line (P) at the inlet (10) of the module and the orifice (SI) to the orifice (E5) of the bore (A2) of the pressure compensator (CPi) and to its pressure orifice (PPE), • a pair of orifices (E2S2) one of which (E2) is connected to the orifice (S4) of the bore (A2) with the interposition of a non-return valve (16) opening in the direction from the orifice (S4) towards the orifice (E2), the other orifice (S2) being connected to a chamber (Cl) of the receiver (Ri), • a pair of orifices (E3, S3) one of which (E3) is connected by the output (11) to the return (T) and the other (S3) is connected to the other chamber of the receiver (Ri), and • the pressure compensator has, in its bore, a pair orifices (E5, S4, S5), the orifice (S4) being connected with interposition of the non-return valve (16) to the orifice (E2 ) of the bore (Al) of the distributor and the orifice (S5) being connected to the other pressure bore (EP2) of the pressure compensator (CPi) and to the junction point (17) with the control line ( LS) in the module (Mi) between its connection points (12) and (13), the drawer (Tl) of the distributor (Di) having passages (P0-P3 bis) for communicating the pairs of orifices ( E0, S0-E3, S3) according to the continuously variable position of the slide (Tl) in the bore (Al):

• the passage (PO) connecting the orifices (E0, S0), • the passage (PI) connecting the orifices (El, SI), • the passage (P2) connecting the orifices (E2, S2), • the passage (P3 ) connecting the orifices (E3, S3), • the passages (P2 bis and P3 bis) reversing the communication between the receiver chambers, • the piston valve (T2) of the pressure compensator (CPi) having passages (PCI, PC2, PC3) connecting, according to the translation position of the piston slide (T2) in the bore (A2), the orifice (E5) to the orifice (S4) or to the orifices (S4) and (S5).

State of the art

There are known multiple control hydraulic circuits formed of a combination of hydraulic modules, stacked and each associated with a receiver. These modules are crossed by different lines (lines) for the passage of hydraulic fluid under pressure and the return, for supplying the receiver associated with each module.

The modules each have a distributor controlled from the outside and independent of each other, thereby supplying and actuating the receivers, for example jacks.

The distributor block supplied by a pump supplies the liquid under pressure. The hydraulic fluid returns from the receiver to the reservoir from which the pump draws.

The distributor drawer has channels for the passage of hydraulic fluid to or from the receiver, depending on the degree of opening of the passages controlling each drawer. These channels are generally distributed over three segments of the drawer:

an intermediate segment which cuts the passage of liquid in both directions, on each side of the intermediate segment, a segment with passages in both directions and another segment alternating the direction of passage of the liquid according to the direction of movement which the receiver (cylinder piston).

In some embodiments, the neutral segment is crossed by a channel so as to communicate the neutral segments when the drawers are in neutral position and form a circulation passage between the pump and the tank. This circulation passage is useful for continuing to filter and cool the hydraulic fluid in the periods of rest between two periods of activity of the hydraulic circuits of the receivers, the pump continuing to flow.

There are also installations with hydraulic distributors operating on the principle of load detection / pressure control LS consisting in detecting the pressure of the maximum load requested by the active receivers, to control the flow rate of the pump with this signal of pressure. In such an installation, when the activity of the receivers is temporarily stopped, the control pressure of the supply pump drops and the pump then only supplies the standby pressure. But the liquid does not circulate and it is neither filtered nor cooled.

In some cases, an outlet valve is provided to allow a minimum flow of liquid to be filtered and cooled.

The development of such installations called pressure control or load detection (under the name LS) has resulted in the LUDV system which allows a better distribution of the flow (flow control) with pressure compensation associated with each distributor.

However, these multiple control hydraulic circuits generate an operating flow rate of the modules or units, associated with each receiver producing transient accelerations which are difficult to manage. LS systems or modes can in principle provide almost instantaneous, high pressures with strong accelerations in the receivers causing the stopping of certain functions and generating vibrations. To avoid this drawback, long and delicate optimizations of the LS system control members are necessary to limit the effect of the hydraulic pulses.

The solutions provided are generally very specific, adapted to specific applications.

Other solutions provide for complementary circuits which considerably complicate distributors.

Purpose of the invention

The object of the present invention is to develop a hydraulic circuit for multiple control of simpler production and operation, avoiding pressure shocks at the start of the activity of a module or at its stop and allowing the circulation of hydraulic liquid out of activity. , for its filtering and cooling.

Presentation and advantages of the invention

To this end, the subject of the invention is a hydraulic multiple control circuit of the type defined above, characterized in that the bore of the distributors has a pair of orifices connected to the neutral line of the module and the distributor drawer has a passage which, in the neutral position of the drawer, connects the orifices.

The hydraulic multiple control circuit according to the invention has the advantage of allowing switching both at the closing of the last module of the distributor and at the opening of the first module avoiding pressure shocks inside the hydraulic circuit supplying the receivers.

The addition of the additional channel allows the establishment of a residual neutral flow useful for cooling and filtering the hydraulic circuit in the standby phase. In addition, the circulation makes it possible to heat the block when starting in cold weather. The additional channel and the passage in the drawer of each of the segments make it possible to modulate the initial pressure rise of each of the functions taken in isolation.

According to another characteristic, the input module has a line derived from the pump line and connected to the neutral line of the modules, the end module having a connection line connecting the neutral line at the output of the last module to the return to The reservoir.

Alternatively, the neutral line ends with an outlet to the tank in the end module.

In addition, the addition of the additional channel allows the establishment of a residual neutral flow useful for cooling and filtering the hydraulic circuit in the standby phase. The circulation makes it possible to warm up the block when starting in cold weather.

According to another advantageous characteristic of the multiple control hydraulic circuit, the neutral line of the module is connected on the one hand to the outlet of the module towards the outlet line and on the other hand, to the orifice of the pressure compensator upstream of the shut-off valve, the inlet module comprising a pump line, a control line and a return line.

This solution allows individual pressure control of each function, one way or the other.

This pressure control intervenes for the need of each segment which is equipped with it, independently of the system pressure; it allows the optimization of pressure control on a clearly identified and dedicated channel or drawer location. This solution is achievable thanks to a few simple additional machining of the body.

According to another advantageous characteristic, the input module comprises a bypass line of the pump line provided with a throttle and downstream of the throttle, a bypass control line connected to a point of the line downstream of the throttle and the pump control, the module control line being cut by the input module and the other end of the control line is connected to the return by means of a throttle in the module end.

This particular embodiment has the advantage of making it possible to control the pressure regulation of the pump without interfering with the line LS of the hydraulic multiple control circuit.

According to another advantageous characteristic of the hydraulic multiple control circuit, the input module comprises a bypass line derived from the pump line and provided with a throttle with, downstream of this throttle, a socket for a pressure line of bypass connected to the pump control, this bypass line being connected to the neutral lines and passing through the modules by the passage of the distributor drawers when the distributors are in neutral position, the neutral line being connected at the end by a connection with the return in the end module which closes the pump and pressure lines, the module pressure line being connected to a pressure line connected in the inlet module to the bypass line downstream of the throttle.

This solution allows pressure control with a through flow restricted by throttling. It continues to operate in regulation when a drawer closes the passage and creates a more vague general dynamic behavior conducive to depreciation because it induces a part of vagueness in the flow sharing.

Drawings

The present invention will be described below, in more detail using different embodiments of a hydraulic multiple control circuit shown in the accompanying drawings in which:

FIG. 1 is a diagram of a first embodiment of a hydraulic multiple control circuit according to the invention, FIGS. 1A-1D are explanatory diagrams extracted from FIGS. 1, 2, 3, 4 and presenting the detail of elements common to the different embodiments:

o figure IA is the diagram of a circuit with a module without the drawers of the distributor and of the pressure compensator, o figure IB is a diagram of the drawer of the distributor, o figure IC is a diagram of the drawer of the pressure compensator , where FIG. ID is a diagram of a variant of the pressure compensator distributor, FIG. 2 shows a second embodiment of the hydraulic multiple control circuit, FIG. 3 is a diagram of a third embodiment of the circuit multiple control hydraulic, Figure 4 is a diagram of the fourth embodiment of the multiple control hydraulic circuit.

Description of embodiments of the invention

The hydraulic multiple control circuit according to the invention will be described below with the aid of four exemplary embodiments 100 / 1-100 / 4 all presented in the case of a hydraulic multiple control circuit composed of two distributor modules. Mi associated with two receivers Ri and supplied with pressurized hydraulic liquid by a pressure-regulated pump 1, the return of liquid T being made to a reservoir 2.

The exemplary embodiments are, according to the technique of the multiple control hydraulic circuits, constituted by modules in the form of wafers provided with bores forming the various pipes and each integrating a distributor Di and a pressure compensator CPi downstream of the distributor Di. The distributor Di is connected to the supply of hydraulic liquid coming from the pump 1 and the output of the distributor Di is connected to the receiver Ri by means of the pressure compensator CPi.

To facilitate the description of the embodiments, the introduction will be made using FIGS. IA, IB, IC, 1D which are extracted from FIG. 1 for detailed explanations using references which are not all repeated in Figures 1 to 4.

According to Figures 1, IA, 2, 3, 4 the hydraulic wafers forming the modules Mi are stacked with, in general, an input module MO and an end module MF at both ends of the stack. The Mi modules (i = l, 2 ...) are all connected in parallel and for this they are provided with holes passing through the edges in identical positions for all the Mi modules so as to form:

a pump line P constituting the pipe coming from pump 1 and supplying each module Mi via its input 10,

a return line T connected to the tank 2 by its outlet 11,

- a LS control line transmitting the control pressure to pump 1 via inputs / outputs 12, 13,

- a neutral LO line between inputs / outputs 20, 21.

Each hydraulic module Mi comprises its hydraulic distributor Di and its pressure compensator CPi, identical or analogous in all the modules Mi. The distributor Di comprises in a generally known manner, a drawer Tl controlled by the operator operating the distributor or by a circuit of ordered. The drawer Tl controls the flow of hydraulic fluid between the supply inlet 10 engaged on the pump line P and the outlets 14, 15 to the receiver Ri. This can be represented schematically in the form of a jack having two chambers C1, C2, one of which is supplied with hydraulic liquid and the other, communicates with the return 11 connected to the return line T, so as to control the movement in one direction or the other following the connection of the two chambers Cl, C2 by the hydraulic distributor Di connected to the inputs / outputs 14, 15.

To allow the direction of supply of chambers C1, C2 to be reversed, the pressure compensator CPi is not connected directly to the receiver Ri but through the distributor Di.

More specifically, according to Figures IA, IB, IC, the distributor Di is assimilated to a bore Al in which the drawer Tl moves; it comprises pairs of orifices (Ei, Si) placed in communication by the drawer Tl. FIG. IA shows the module Mi without the drawer Tl of the distributor Di and without the drawer T2 of the pressure compensator CPi to simplify the presentation.

As in certain cases, the hydraulic fluid can circulate in the two directions, certain orifices are called inlets / outlets.

The drawer T1 of the distributor Di is shown separately in FIG. 1B; the drawer T2 of the pressure compensator CPi is shown separately in Figure IC and the variant T3 of the drawer T2 of the pressure compensator is shown in Figure ID.

In this general description, certain references are assigned the index i (i = 0, 1, ...) to avoid explicit repetitions of all the references designating analogous elements of a set in the same embodiment or Similar elements found in some of the embodiments of Figures 1-4.

The bore A1 of the distributor Di comprises: a pair of orifices E0, S0 connected to the neutral line LO passing through the module Mi and emerging through the inputs / outputs 20, 21, (or 20 / i; 21 / i) a pair orifices El, SI the orifice El of which is connected to the pump line P at point 10 and the orifice SI to the bore A2 of the pressure compensator CPi. This link is divided between a branch connected to the orifice E5 of the bore A2 and a branch connected to the pressure orifice EPI of the compensator CPi, a pair of orifices E2, S2 one of which, E2, is connected to the orifice S4 of the bore A2 with the interposition of a non-return valve 16 opening in the direction going from S4 to E2; the other orifice S2 is connected to the chamber Cl of the receiver Ri by the input / output 14, a pair of orifices E3, S3 one of which, E3, is connected to the return by the output 11 and the other, S3, is connected to the other chamber C2 of the receiver Ri by the input / output 15.

The drawer Tl of the distributor (FIG. 1B) diagrammed here in a conventional manner, really only comprises the passages P0P3bis passing through the drawer Tl. The other elements will be described later.

The different passages of the drawer Tl have the function of bringing the pairs of orifices (E0, S0-E3, S3) into communication according to the continuously variable position of the drawer Tl in the bore Al.

So :

the passage PO connects the orifices E0, S0, the passage PI connects the orifices El, SI, the passage P2 connects the orifices E2, S2, the passage P3 connects the orifices E3, S3.

The passages P2bis and P3bis reverse the communications that the passages P2, P3 carry out with the inputs / outputs 14, 15:

the passage P2bis connects the orifices E3, S2, the passage P3bis connects the orifices E2, S3.

The relative positions of the openings E0-S3 and the passages P0-P3bis are such that all the passages and all the orifices are not put into communication simultaneously (independently of the continueο continuous variation of the communication according to the continuous displacement of the drawer Tl in the bore A1). This is the case only when the drawer Tl is completely positioned opposite the associated orifices (end positions).

Thus, for the end-of-travel positions: the passage PO communicates by EO, SO with the line LO, while none of the other passages Pl-P3bis establishes communication with any of the other orifices E1-S3;

the passages P1-P3 communicate simultaneously with the pairs of orifices (El, S1-E3, S3) while the passage PO is not in communication with the orifices EO, SO;

the passages PI, P2bis, P3bis communicate with the orifices ElS3 simultaneously and the passage PO is not in communication with the orifices EO, SO.

These different states of end of travel of the drawer Tl are shown diagrammatically on the drawer Tl of FIG. 1B in the form of segments SO, SI, S2. This conventional representation is imperfect, even misleading because it does not allow to reflect the continuity of the movement between the three end-of-travel states represented by the S0-S2 segments. The movement of the Tl drawer is indicated by the double arrow (FL).

The principle of the representation of the pressure compensator is due to the same difficulties in presenting the continuous movement of its drawer (which is here a piston-drawer) T2 in the bore A2.

The bore A2 has on one side an orifice E5 connected to the orifice SI of the bore Al and on the other side, two orifices S4 and S5. The orifice S4 is connected to the orifice E2 of the bore Al as has already been described. Port S5 is connected to line LS by junction 17.

The bore A2 forms at each of its ends, a chamber, one of which has a pressure port EPI connected to the port SI of the bore Al and the other, a pressure port EP2 connected to the line LS. The drawer T2 has two faces F1, F2, one of which, F1, is located in the chamber of the bore A2 into which the pressure orifice EPI opens and the other, F2, is in the chamber in which the opening l orifice EP2.

The T2 piston drawer has two PCI, PC2 passages. The relative positions of the openings E5, S4, S5 and the passages PCI, PC2 are such that all the passages and the orifices are not put in communication simultaneously and the displacement of the piston drawer T2 pushed by the difference of the pressures applied on the two sides F1, F2, can take the following end positions, separated by continuous transitions:

a cut-off position when no PCI passage, PC2 is opposite the orifice E5 and one of the orifices S4, S5, a first end-of-travel position when the PCI passage places the orifice E5 in communication with the orifice S4, a second end-of-travel position when the passage PCI places the orifice E5 in communication with the orifice S4, and the passage PC2 places the orifice E5 in communication with the orifice S5.

These three states are shown diagrammatically by the three segments SSO, SS1, SS2 according to the traditional principle of the representation of a hydraulic distributor drawer.

It should be noted in this representation that the segment SS2 represents both the passage PC2 and the passage PCI. This actually means that when the drawer T2 is moved from its position SS1, the PCI passage remains in complete communication with the orifices E5, S4 (without throttling of the communication openings) and gradually the PC2 passage also puts the orifice E5 in communication with port S5.

According to FIG. 1, for the first embodiment of the hydraulic multiple control circuit 100/1 in each module Mi (i = 1.2 ...), the neutral line LOi (i = 1.2) of each module Mi is connected to the inputs / outputs 20, 21 so that the neutral lines LOi of all the modules Mi are connected.

In the MF end module (i = l), the neutral line LOi is connected by the LOF link to the return line T. In the input module MOi (i = 1), the pump line P is subdivided into a branch PLO which is connected to the input / output 20 of the first module M1 of the stack of modules Mi.

When the drawers Ti of all the distributors Di (i = 1.2 ...) are in neutral position, the complete and continuous neutral line LO, formed by the neutral lines LOi of the modules Mi and the passages PO of the distributors Di, thus connects the PLO branch at return T via the LOF branch.

In this neutral position of all the distributors Di of 100/1, the inputs 10 and the outputs 11 with the pump line P and the return T are cut off so that the pump 1 will only supply in the neutral line LO. Hydraulic fluid can therefore circulate, be filtered and cooled. This neutral state is a waiting state between two periods of activity of the Ri receptor (s).

When one of the receivers must be controlled, for example the receiver RI, its distributor DI of the module Ml is actuated to gradually drive the segment S1 to the active position (see FIGS. IA, IB). The drawer Tl gradually communicates the pairs of orifices (El, SI; E2, S2; E3, S3) and conversely reduces the communication between the orifices E0 and S0.

The hydraulic fluid continues to pass through the neutral line LO (the operating hypothesis assumes that the other modules Mi are always at rest) and in parallel, the pump line P supplies the receiver RI through the distributor DI (the passage PI opposite the orifices El, SI) then through the pressure compensator CPI which connects the orifices E5, S4 to conduct the hydraulic fluid through the orifices E2, S2 towards the inlet / outlet 14 and supply the chamber Cl while the chamber C2 is connected with the output 11 and the return T by the input / output 15, the connection between the orifices S3, E3 and the passage P3.

These combined openings / closings avoid any pressure shock (water hammer) when the Ml module is activated.

FIG. 2 shows a second embodiment of the hydraulic multiple control circuit 100/2 to which the same basic considerations apply as those developed in preliminary above.

In this 100/2 embodiment, the neutral line LO2 is specific to each module Mi and these neutral lines LO2 do not communicate with each other. The description will be made for the Ml module. In principle, the explanations will be limited to this module since the object of the invention is to avoid pressure shocks when the dispenser passes from its active state to its neutral state or vice versa.

Each of the segments is autonomous and can regulate the rise in pressure towards the receiver attached to it.

According to Figure 2, the structures of the two modules Ml, M2 are the same, so the description will be limited to the module Ml. The module Ml has its neutral line LO2 connected by the junction 20/2 to the orifice E3 or at point 11 since it is connected to the connection between these two orifices; the neutral line is connected by junction 21/2 to port S4 upstream of the non-return valve 16.

In this embodiment of the 100/2 multiple control hydraulic circuit, there is no return to the tank T when all the modules Mi are neutral and the end module MF2 is limited to plugging the pipes P, LS , T. The pressure is checked individually in each module Mi. When the distributor Di approaches its neutral position, the pump 1 controlled by pressure by the line LS in which the pressure gradually decreases, cancels its flow rate and maintains its waiting pressure as in LS load detection mode.

Conversely, when the module M1 becomes active again, at the beginning, part of the flow rate of pump 1 through the pump line P and the pressure compensator CP2 is derived by the junction 21/2 towards the neutral line LO2 and the passage PO to '' at junction 20/2 and therefore towards the return T.

This branch link, important for avoiding the pressure shock on resumption of activity, is gradually closed by the drawer Tl so that an increasingly large part of the flow rate of the pump 1 arrives at the receiver RI and at the end of movement of the drawer Tl, the passage PO is cut and all the flow feeds the receiver RI associated with the module Ml.

The reverse movement occurs at the time of closing since then an increasing part of the flow will be taken at the outlet of the pressure compensator CPi to pass through the passage PO towards the junction 20/2 and the return T; this also has the parallel consequence of reducing the control pressure in the line LS, the pressure supplied by the passage PC2 of the drawer T2 and the connection 17 gradually decreases, depending on the pressure arriving from the pump line P through the distributor DI to port E5. The pressure then arrives at the standby pressure when the passage through PO is open, the drawer Tl arriving towards its neutral position.

Thus, both when the first active module (Mi) is started and when the last active module (Mi) is stopped, there will be no pressure shock in the 100/2 multiple control hydraulic circuit.

FIG. 3 shows a third embodiment of the hydraulic multiple control circuit 100/3 showing the basic elements described with the aid of FIGS. IA, IB, IC. The neutral line LO3 crosses the input module MO3 from the PLO bypass of the pump line P and in the end module MF3 it is connected by the LOF link to the return T.

In the input module MO3, the line PLO is provided with a throttle 40 and beyond this, a bypass LSx constitutes the control line connected to the pump 1.

The command line LS crosses the modules Mi and is connected to the pressure compensators CPi by the junctions 17 and to the return T by a throttle 41 in the end module MF3. But this LS line is not connected to pump 1.

Switching to the neutral position of the last active module Μ1 establishes communication via the neutral line LO3 connecting the pump line P to the return T through the throttle 40. When the drawer Tl of the distributor DI begins to reach the neutral position, the passage PO opens the neutral line LO3 (the other distributors are by hypothesis already or still in neutral position) and the hydraulic fluid is withdrawn from the pump line P so that the pressure downstream of the throttle 40 decreases. However, this pressure is the control pressure of pump 1 by the line LSx. The pressure downstream of the throttle 40 gradually approaches the pressure of the return T so that the pump 1 will only deliver a very low flow to circulate the hydraulic fluid, filter and cool it.

Conversely, when resuming activity, when the first module (for example Ml) begins to be active again, its drawer Tl gradually opens the passage Po which thus progressively cuts the neutral line LO3 and increases the pressure downstream of the throttle 40 via the LSx command line, until the LO3 line is completely closed and completely cut off.

This 100/3 multiple control hydraulic circuit avoids pressure shocks when the last active Mi module is closed (stopped) and when one of the modules starts operating again.

FIG. 4 shows another embodiment of the multiple control hydraulic circuit 100/4 which takes up the elements described with the aid of FIGS. 1A-1D.

In this multiple control hydraulic circuit 100/4, the neutral lines LO4 of the modules Mi communicate as in the embodiment 100/3 with the bypass PLO of the pump line P of the input block MO4 which has a throttle 40 with downstream, the control line LSx of pump 1. The line LS cut off from the control of pump 1, is not connected to the tank T by the end module MF4. It is connected to the PLO line downstream of the throttle 40 in the MO4 input module.

The LO4 neutral line is connected to the T feedback in the MF4 module by the LOF link.

The drawer T3 of the pressure compensator CPi has a passage PC3 with a throttle (FIG. 1D) so that the drawer T3 establishes a choked communication with the orifice S5, which makes it possible to simply combine a hydraulic pressure control system with a LUDV debit sharing system.

The 100/1 embodiment involves the flow of a large flow of fluid in standby mode, flow determined by the pressure drop of the set LOI, LOF, T and the pressure difference of pump regulation.

The 100/3 embodiment involves the flow of the restricted flow of fluid in the standby phase, flow determined by the section of the nozzle 40 and the difference in pressure of the pump.

The 100/4 embodiment combines the advantages of the two embodiments 100/1 and 100/3. The known problem of disappearance of the pressure difference at the closure of the flow in line L04 is resolved by the continuation through the compensators to the receivers.

The various embodiments 100/1, 100/3, 100/4 of the hydraulic multiple control circuit are distinguished only by the input module MO and the end module MF while the embodiment 100/2 comprises two additional bores, îo Thus, and as explained above, very simple and small modifications make it possible to have very different operating characteristics from one embodiment to another.

100 / 1-100 / 4

12, 13 14, 15 16 17

20, 20 / i

21, 21 / i 40, 41 Al

A2

Cl, C2

CPi

Sun

Ei, Si EPI, EP2

Fl, F2

FL

LS

LSx

LO

Mid

Mo

MF

P

PO, PI, P2, P3, PCI, PC2, PC3 Ri

S1-S5

NOMENCLATURE

Multiple control hydraulic circuits

Pump

Tank

Module power input

Module output to return T

LS command line inputs / outputs

Input / output to Ri receiver

Non-return valve

Junction

Neutral line input / output Neutral line input / output Chokes

Distributor bore

Pressure compensator bore

Receiver chambers

Pressure compensator Distributor

Pair of dispenser ports

Pressure ports of the pressure compensator bore Piston drawer faces T2 Drawer movement direction Tl Command line Bypass control line Neutral line

Current module / module Input module End module Pump line

P3bis Passages of the Tl drawer

Piston-drawer passages Receiver

Drawer segments T1

SS0-SS2

T

Tl

T2

T3

Piston drawer T2 or T3 Return line Distributor drawer

Pressure compensator drawer / piston Pressure compensator drawer variant

Claims (5)

1 °) Multiple control hydraulic circuit formed by the assembly of hydraulic modules each associated with a receiver to activate it in a controlled manner via a slide valve (Di) combined with a pressure compensator (CPi) and having : a pump line (P) connecting the controlled pump (P) to the input of the module supply (Mi), a return line (T) connecting the output of the receivers (Ri) to the tank (2) of the pump (1), a control line (LS) controlling the pump (1) by a control pressure depending on the operation of the receivers (Ri), each distributor (Di) having a drawer with: • a pair of orifices (E0, S0) connected to the neutral line (LO) of the module (Mi), • a pair of orifices (El, SI) whose orifice (El) is connected to the pump line (P) at the inlet (10) of the module and the orifice (SI) to the orifice (E5) of the bore (A2) of the pressure compensator (CPi) and to its pressure orifice (PPE), • a pair of orifices (E2S2) one of which (E2) is connected to the orifice (S4) of the bore (A2) with the interposition of a non-return valve (16) opening in the direction from the orifice (S4) towards the orifice (E2), the other orifice (S2) being connected to a chamber (Cl) of the receiver (Ri), • a pair of orifices (E3, S3) one of which (E3) is connected by the output (11) to the return (T) and the other (S3) is connected to the other chamber of the receiver (Ri), and • the pressure compensator has, in its bore, a pair orifices (E5, S4, S5), the orifice (S4) being connected with interposition of the non-return valve (16) to the orifice (E2 ) of the bore (Al) of the distributor and the orifice (S5) being connected to the other pressure bore (EP2) of the pressure compensator (CPi) and to the junction point (17) with the control line ( LS) in the module (Mi) between its connection points (12) and (13), the drawer (Tl) of the distributor (Di) having passages (P0-P3 bis) for communicating the pairs of orifices ( EO, S0-E3 bis, S3 bis) depending on the continuously variable position of the slide (Tl) in the bore (Al): • the passage (PO) connecting the orifices (EO, SO), • the passage (PI) connecting the orifices (El, SI), • the passage (P2) connecting the orifices (E2, S2), • the passage (P3 ) connecting the orifices (E3, S3), • the passages (P2 bis and P3 bis) reversing the communication between the receiver chambers, • the piston valve (T2) of the pressure compensator (CPi) having passages (PCI, PC2, PC3) connecting, according to the translation position of the piston slide (T2) in the bore (A2), the orifice (E5) to the orifice (S4) or to the orifices (S4) and (S5), hydraulic circuit of control characterized in that the bore (Al) of the distributors (Di) has a pair of orifices (EO, SO) connected to the neutral line (LOi) of the module and the spool (Tl) of the distributor (Di) has a passage (PO) which, in the neutral position of the drawer, connects the orifices (EO, SO). 2) hydraulic multiple control circuit according to claim 1, characterized in that the input module (MOI) has a line (PLO) derived from the pump line (P) and connected to the neutral line (LOi) of modules (Mi), the end module (MF) having a connection line (LOF) connecting the neutral line (LO) at the output of the last module (Mi) to the return (T) to the tank (2). 3 °) multiple control hydraulic circuit according to claim 1, characterized in that the neutral line (LO2) of the module (Mi) is connected on the one hand to the output (20/2, 11) of the module to the line of outlet (T) and on the other hand, at the orifice (S4) of the pressure compensator upstream of the shut-off valve (16), the inlet module (MO) comprising a pump line (P), a control line (LS) and a return line (T), while the end module (FM2) closes the pump (P), pressure (LS) and return (T) lines. 4 °) multiple control hydraulic circuit according to claim 1, characterized in that the input module (MO3) comprises a bypass line (PLO) of the pump line (P) provided with a throttle (40) and downstream of the throttle, a bypass control line (LSX) connected to a point on the line (PLO) downstream of the throttle (40) and at the pump control (1), the control line (LS) modules being cut by the input module (MO3) and the other end of the control line (LS) is connected to the return (LOF, T) via a throttle (41) in the end module (MF3). 5 °) multiple control hydraulic circuit according to claim 1, characterized in that the input module (MO4) comprises a bypass line (PLO) derived from the pump line (P) and provided with a throttle (40 ) with, downstream of this throttle (40), a socket for a bypass pressure line (LSx) connected to the pump control (1), this bypass line (PLO) being connected to neutral lines (LO4) and crossing the modules the passage (PO) of the distributor drawers (Tl) when the distributors (Di) are in neutral position, the neutral line (LO4) being connected at the end by a link (LOF) with the return (T) in the end module (MF4) which closes the pump (P) and pressure (LS) lines, the pressure line (LS) of the modules (Mi) being connected to a pressure line (LS) connected in the module inlet (MO4) to the bypass line (PLO) downstream of the throttle (40). 1/5 100/1 LL CM