EP0582498A1 - Control system for a plurality of hydraulic actuators - Google Patents

Control system for a plurality of hydraulic actuators Download PDF

Info

Publication number
EP0582498A1
EP0582498A1 EP19930401787 EP93401787A EP0582498A1 EP 0582498 A1 EP0582498 A1 EP 0582498A1 EP 19930401787 EP19930401787 EP 19930401787 EP 93401787 A EP93401787 A EP 93401787A EP 0582498 A1 EP0582498 A1 EP 0582498A1
Authority
EP
European Patent Office
Prior art keywords
pressure
upstream
throttle
drawer
compensating
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP19930401787
Other languages
German (de)
French (fr)
Other versions
EP0582498B1 (en
Inventor
Jean-Louis Claudinon
André Rousset
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Marrel SA
Original Assignee
Marrel SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Marrel SA filed Critical Marrel SA
Publication of EP0582498A1 publication Critical patent/EP0582498A1/en
Application granted granted Critical
Publication of EP0582498B1 publication Critical patent/EP0582498B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
    • F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
    • F15B13/0416—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor with means or adapted for load sensing
    • F15B13/0417—Load sensing elements; Internal fluid connections therefor; Anti-saturation or pressure-compensation valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F15B11/161—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load
    • F15B11/163—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load for sharing the pump output equally amongst users or groups of users, e.g. using anti-saturation, pressure compensation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F15B11/161—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load
    • F15B11/165—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load for adjusting the pump output or bypass in response to demand
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F15B11/161—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load
    • F15B11/168—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load with an isolator valve (duplicating valve), i.e. at least one load sense [LS] pressure is derived from a work port load sense pressure but is not a work port pressure itself
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205—Systems with pumps
    • F15B2211/2053—Type of pump
    • F15B2211/20546—Type of pump variable capacity
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/25—Pressure control functions
    • F15B2211/253—Pressure margin control, e.g. pump pressure in relation to load pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/30525—Directional control valves, e.g. 4/3-directional control valve
    • F15B2211/3053—In combination with a pressure compensating valve
    • F15B2211/30535—In combination with a pressure compensating valve the pressure compensating valve is arranged between pressure source and directional control valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/31—Directional control characterised by the positions of the valve element
    • F15B2211/3105—Neutral or centre positions
    • F15B2211/3111—Neutral or centre positions the pump port being closed in the centre position, e.g. so-called closed centre
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/31—Directional control characterised by the positions of the valve element
    • F15B2211/3144—Directional control characterised by the positions of the valve element the positions being continuously variable, e.g. as realised by proportional valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/315—Directional control characterised by the connections of the valve or valves in the circuit
    • F15B2211/3157—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source, an output member and a return line
    • F15B2211/31576—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source, an output member and a return line having a single pressure source and a single output member
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/32—Directional control characterised by the type of actuation
    • F15B2211/327—Directional control characterised by the type of actuation electrically or electronically
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/50—Pressure control
    • F15B2211/505—Pressure control characterised by the type of pressure control means
    • F15B2211/50509—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
    • F15B2211/50518—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using pressure relief valves
    • F15B2211/50527—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using pressure relief valves using cross-pressure relief valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/605—Load sensing circuits
    • F15B2211/6051—Load sensing circuits having valve means between output member and the load sensing circuit
    • F15B2211/6054—Load sensing circuits having valve means between output member and the load sensing circuit using shuttle valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/605—Load sensing circuits
    • F15B2211/6058—Load sensing circuits with isolator valves
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/8593—Systems
    • Y10T137/87169—Supply and exhaust

Definitions

  • the invention relates to a control assembly for a plurality of hydraulic receivers, through which the receivers are supplied by the same generation of flow, each being connected thereto by means of a proportional distributor.
  • distributors are devices that are available between a flow generation and a receiver to control the operation of the receiver by adapting the way it is connected to the flow generation.
  • Proportional type distributors include not only a controlled drawer whose position determines the section of a constriction, but also an automatic compensating drawer to maintain constant the pressure difference between the upstream and downstream of this constriction, so that at a given position of the controlled slide corresponds to a given flow of fluid. Consequently, when a receiver is controlled with a proportional distributor, its operating speed is fixed by the position of the controlled drawer, independently of the load that the receiver supports.
  • FR-A-2.339.757 proposes to act on the actuation pressure of the slide controlled in each of the proportional distributors, by providing that the actuation valves are no longer supplied directly from a pilot pump, but with interposition between the pilot pump and the actuation valves of a maneuvering valve which varies the supply pressure of the control valves in the same way as the difference between the pressure of the flow generation and the pressure of load -sensing.
  • the supply pressure of the control valves remains constant, just as if these valves were supplied directly by the pilot pump.
  • FR-A-2.548.290 proposes to achieve the same result in the case where the proportional distributors have a compensating drawer which is located upstream of the controlled drawer, by acting on the actuating means of the compensating drawer: it continues to be used in the direction of closing by the pressure upstream of the controlled drawer and in the direction of opening by the pressure downstream of the controlled drawer, but the conventional spring is replaced by a double pressure stress, respectively in the direction of closing by the load-sensing pressure and in the opening direction by the pressure of the flow generation.
  • the pressure difference between the upstream and downstream of the throttle of the controlled slide is thus controlled by the difference between the pressure of the flow generation and the load-sensing pressure, which leads to the abovementioned result.
  • the invention aims to obtain this same result, but with improved performance.
  • a response time of the compensating drawer is obtained which is particularly rapid, in particular compared to the aforementioned state of the art since the maximum of the pressures upstream of the respective first throttles is higher than the load-sensing pressure.
  • said assembly thus being adapted to be used with a generation of flow producing a working pressure normally equal to a regulating pressure which is applied thereto, called load sensing, increased by a constant.
  • said means for actuating the compensating slide comprise: on the latter, a first active surface subjected to pressure downstream of the first throttle, a second active surface subjected to pressure upstream of the second throttle, a third active surface subjected to the pressure upstream of the first constriction, and a fourth active surface subjected to said maximum of the pressures upstream of the respective first constrictions, said first and second surfaces being opposite to said third and fourth surfaces; as well as a spring urging the compensating drawer in the closing direction.
  • This second embodiment differs from the first by the presence of the auxiliary valve, the pressure produced is applied in place of the pressure upstream of the second throttle. This makes it possible to avoid the difficulties which occur when the pressure upstream of the second throttle is not the same in the respective distributors, as a result of different pressure drops between the flow generation and the respective distributors.
  • this embodiment offers the advantage of being able to provide the desired result even if the flow generation is not regulated as a function of the load supported by the receivers.
  • said means for actuating the compensating slide comprise thereon a first active surface subjected to the pressure downstream of the first throttle, a second active surface subjected to the pressure produced by the auxiliary valve, a third active surface subjected to the pressure upstream of the first constriction, and a fourth active surface subjected to said maximum of the pressures upstream of the respective first constrictions, said first and second surfaces being opposite to said third and fourth surfaces; as well as a spring urging the compensating drawer in the closing direction.
  • said first and third active surfaces of the compensating drawer have a similar dimensioning
  • said second and fourth surfaces of the compensating drawer have a similar dimensioning
  • the assembly comprises for each group a so-called auxiliary valve neighboring the group.
  • each proportional distributor there is no non-return valve between said second throttle and first throttle.
  • the invention makes this check valve provided in all prior proportional distributors unnecessary. This stems from the fact that we are sure that at rest (when all the ordered drawers are neutral), all the compensating drawers are closed: if we make an inventory of the stresses that apply in the direction of closing and those which apply in the opening direction, taking into account that at rest the pressure downstream of each compensating slide is equal to the pressure upstream (even if the compensating slide is closed, at because of the inevitable tiny leaks), it can be seen that the forces which apply in the direction of closing are always greater than those which apply in the direction of opening.
  • said means for detecting the maximum of the pressures upstream of the first respective throttles comprise a common pipe closed at a first end and opening into the tank through a restriction at a second end; and for each proportional distributor a non-return valve arranged passing between the upstream of the first throttle and the common pipe.
  • the distributor 70 illustrated in FIG. 1 is similar to that described in FR-A-2,562,632, with the exception of its pressure compensating device.
  • stator block 1 in the bore 2 of which slides a cylindrical controlled drawer 3.
  • switching of the hydraulic circuits is effected by displacement of the grooves of the drawer 3 in front of the lights of the stator.
  • the drawer 3 is provided with a spring return device of known type, comprising a helical spring 4, compressed between the shoulders 5 and 6 of two rings 7 and 8, trapped between two shoulders of the end 9 of the drawer 3, around which they can slide.
  • a spring return device of known type, comprising a helical spring 4, compressed between the shoulders 5 and 6 of two rings 7 and 8, trapped between two shoulders of the end 9 of the drawer 3, around which they can slide.
  • the drawer 3 is spontaneously returned to a neutral rest position, while it is pushed to the right (FIG. 1) when a pilot pressure is sent into an opening 10 of the fixed cap 61.
  • a pilot pressure is sent opposite, in an opening 11 of the cap 62 at its other end.
  • the three-position slide 3 is used to control a double-acting hydraulic cylinder 12.
  • one of the sections of the cylinder 12 is connected to a first channel use 13 of the stator 1, while the opposite section of the jack 12 is connected to a second use pipe 14 of the stator 1.
  • the distributor receives in an annular chamber 15, the pressure sent by a generation of flow 71.
  • the supply chamber 15 surrounds a compensating drawer 16, also called a balance, which is movable in a bore 80 of the stator 1, and which has a groove 81 which produces, depending on the position of the drawer 16, a more or less constriction. important between the chamber 15 and an annular chamber 27 surrounding the central part of the controlled drawer 3.
  • the controlled slide 3 has an axial internal housing, 28 on the left, 29 on the right.
  • the housing 28 communicates with the outside of the drawer by two radial bores referenced respectively 30 and 31. Likewise, the housing 29 opens onto two radial bores 32 and 33.
  • the bore 30 faces a solid part 34 of the stator which closes it, between two annular chambers 35 and 36.
  • the chamber 35 communicates with the first use pipe 13, while room 36 is connected to the return circuit.
  • the bore 32 is closed at rest, by a solid part 37, located between two annular chambers 38 and 39.
  • the chamber 38 communicates with the second use pipe 14, while the chamber 39 is connected to the return circuit .
  • the stator defines, in the bore, a solid part 40, in front of which is capable of moving a groove 41 of the drawer 3.
  • annular stator chamber 42 Around the drawer 3, in the zone situated around the bore 31 when the drawer 3 is pushed to the right (FIG. 1), there is an annular stator chamber 42.
  • the drawer 3 has a groove 43 movable in front of a solid part 44 of the stator.
  • a solid part 44 of the stator Around the passage 33 when the drawer 3 is pushed to the left, there is an annular stator chamber 45.
  • the two chambers 42 and 45 are connected by a pipe 46 called the load sensing pipe.
  • a first booster valve 52 is mounted in parallel on the first use pipe 13.
  • a booster valve 53 is mounted in parallel on the second user pipe 14. Behind the valves 52 and 53, is finds a chamber 54 connected to the oil return circuit.
  • a pressure relief valve, respectively 55 and 56, is provided on the side of each of the use pipes 13, 14, which can thus flow into the return chambers, respectively 36, 39.
  • the chambers 27, 35 and 38 are closed, so that the jack 12 is immobilized while no flow passes through the distributor.
  • the pipe 46 communicates through the grooves 41 and 43 respectively with the chamber 36 and the chamber 39, that is to say that it is connected to the return circuit.
  • the slide 3 slides to the right with an amplitude determined by the value of the pilot pressure, which is balanced with the opposing thrust of the spring 4, more or less compressed.
  • the supply pressure of the chamber 27 is sent into the line 13 through the groove 49 and the chamber 35, while the line 14 communicates with the return chamber 39 through the groove 51.
  • Each of the grooves 49 and 51 determines a throttle whose section is determined by the position of the slide 3.
  • the pipe 46 communicates on the left with the pipe 13 through the passages 31, 28 and 30, while on the right it is closed. The pressure downstream of the throttle provided by the groove 49 is thus transmitted to the pipe 46.
  • the slide 3 slides to the left to a position determined by the amplitude of the pilot pressure.
  • the supply pressure of the chamber 27 is sent into the line 14 passing through the groove 50 and the chamber 38, while the line 13 communicates with the return chamber 36 through the groove 48.
  • Each of the grooves 48 and 50 determines a constriction, the section of which is determined by the position of the drawer 3.
  • the pipe 46 communicates on the right with the pipe 14 by the holes 33, 29 and 32, while on the left it is closed. The pressure downstream of the throttle provided by the groove 50 is thus transmitted to the pipe 46.
  • the circuit selector 99 (also called OR function) has one of its inputs which communicates with the pipe 46 by a channel 72, and its other input which communicates with a channel 73 connected to the output pipe of the circuit selector d '' a similar distributor.
  • the pressure in the line 46 is the highest, so that the circuit selector 99 adopts the illustrated position where it transmits by its output to the line 74 the operating pressure of the cylinder 12, which is the pressure of highest use of all the receivers supplied by the flow generation 71. More generally, as it can be seen clearly in FIG. 2, it is always the pressure of the most loaded receiver which is applied to the pipe 74, this so-called load sensing pressure being transmitted to the generation of flow 71 which produces an operating pressure normally equal to the load sensing pressure increased by a constant.
  • the compensating slide 16 closes the passage between the chambers 15 and 27, but when it moves to the left it produces, depending on its position, a more or less significant constriction upstream of the throttle provided by the slide 3 on the supply line of the jack 12.
  • the slide 16 has a first active surface 82 subjected to the pressure downstream of the throttle provided by the slide 3, a second active surface 83 subjected to the pressure upstream of the throttle provided by the slide 16, a third active surface 84 subjected to the pressure upstream of the throttle provided by the drawer 3, and a fourth active surface 85 subjected to the pressure prevailing in a chamber 86 located to the left of the drawer 16.
  • the surfaces 82 and 83 look to the right, and are opposed to the surfaces 84 and 85 which look towards the left. Since the drawer 16 closes the constriction which it produces when it moves from the left to the right and vice versa, the pressures to which the surfaces 82 and 83 are subjected urge the drawer 16 in the direction of the opening while the pressures to which the surfaces 84 and 85 are subjected urge it in the closing direction.
  • a spring 87 is provided in the chamber 86 between the bottom of the latter, located on the left, and the surface 85, which means that the slide 16 is also biased in the closing direction by a substantially constant force. To adjust the latter, a screw 88 is provided which forms the bottom of the chamber 86.
  • the surface 82 is subjected to the pressure prevailing downstream of the throttle provided by the slide 3 because it is disposed in a chamber 89 communicating with the pipe 46 by a conduit 90, and the surface 84 is subjected to the prevailing pressure upstream of the constriction provided by the drawer 3 because it is disposed in a chamber 91 communicating with the chamber 27 by a conduit 92.
  • the drawer 16 is provided with a radial bore 93 communicating with a blind axial bore 94 which opens onto a seat capable of being closed off or unmasked by a ball 95 whose return spring 96 is compressed in a chamber 98 which opens out an axial opening 100 in the chamber 86.
  • This communicates via a passage 101 with a pipe 102 closed at one end and opening into the flow generation reservoir through a restriction 104 at the other end, the pipe 102 being common to all distributors, who have their room corresponding to 86 which is connected to it.
  • FIG. 2 shows a control assembly according to the invention, formed of a single group of two contiguous distributors, respectively the distributor 70 illustrated in FIG. 1, and an identical distributor 70 ', all the elements of the latter carrying the same reference as distributor 70, but assigned a prime index.
  • the common pipe 102 is connected upstream of the throttle provided by the drawer 3 by means of a non-return valve whose ball 95 forms the shutter , this non-return valve being passing towards the pipe 102. Consequently, there prevails in the latter the pressures prevailing upstream of the throttles provided by the drawers 3 and 3 ′, the restriction 104 achieving a decompression of the pipe. 102 which allows the continuous adjustment thereof to the maximum of the pressures upstream of the drawers 3 and 3 '. It is therefore this last pressure which prevails in the chamber 86 and in the corresponding chamber of the distributor 70 '.
  • the surfaces 82 and 84 have a similar dimensioning, denoted S 2
  • the surfaces 83 and 85 have a similar dimensioning, denoted S 1 .
  • the pressure difference P - MAX (P) remains constant as long as the flow generation is able to satisfy the total demand for flow, while it is less than this constant when there is excess demand for flow, the decrease being all the greater the excess demand is.
  • the pressure MAX (P) prevailing in the pipe 102 is used to regulate the generation of flow rate, instead of the load-sensing pressure prevailing in the pipe 74.
  • This variant is less interesting than that illustrated, since it is less easy to regulate a flow generation when the difference between the regulating pressure and the operating pressure becomes smaller.
  • the proportional distributor 170 shown in FIG. 3 comprises a compensating drawer 116, the straight part of which is different from that of the drawer 16: it comprises, opposite the active surface 83, an active surface 300 having the same effective value, that is to say say S 1 , another active surface 301 is subjected to the pressure downstream of the throttle provided by the slide 3, and yet another active surface 302 is subjected to the pressure produced by an auxiliary valve 303.
  • the surfaces 301 and 302 look to the right, they are therefore opposed to the surfaces 84 and 85, the pressures to which they are subjected therefore urge the drawer 116 in the direction of opening.
  • the surface 301 is subjected to the pressure prevailing downstream of the throttle provided by the slide 3 because it is disposed in the pipe 146, and the surface 302 is subjected to the pressure produced by the valve 303 because it is disposed in a chamber 304 connected by a pipe 305 to the valve 303.
  • the active surface 301 has an effective value similar to that of the surface 84, i.e. S 2
  • the surface 302 has an effective value similar to that of the surface 85, i.e. S 1 .
  • the auxiliary valve 303 comprises a stator body 306 which defines a supply chamber 307 connected to the discharge orifice of the flow generation 71; a regulation chamber 308 in which MAX (P ; ) prevails; an outlet chamber 309 where said pressure produced prevails; a drawer 310 whose position determines, thanks to a groove 311, the section of a constriction between the chambers 307 and 309; and a spring 312 which acts on the slide 310 in the opening direction, a screw 313 being provided to adjust the force with which the spring acts.
  • MAX (P) prevails in the chamber 308 because this chamber is connected to the pipe 102.
  • the drawer 310 has a first active surface 314 disposed in the chamber 308, and therefore subjected in the direction of opening to MAX (P ) and a second active surface 315 arranged in the chamber 309, so that the pressure produced acts on the surface 315 in the direction of closing.
  • the pressure produced is therefore independent of the pressure supplied by the generation of flow, which makes it possible to avoid the difficulties which one could encounter in the embodiment of FIGS. 1 and 2 due to the fact that one could have in certain proportional distributors of the different pressures upstream of the throttle provided by the compensating slide, in particular in the case where these distributors are located at a different distance from the flow generation, and therefore there are different pressure losses between the discharge pressure thereof and the pressure prevailing in the chamber referenced 15.
  • the proportional distributors of the control unit are divided into several groups of a distributor or of several neighboring distributors, the groups being distant from each other, for example in the case of a public works machine, divided into a first group of two distributors which controls the right and left engines for advancing the vehicle, a second group of a single distributor which controls the rotation of a turret, and a third group of several distributors which controls the different arms of the machine, it is preferable to provide an auxiliary valve for each group, not only to avoid pressure drop problems, but also to avoid having to provide a pipe between a centralized auxiliary valve and the different groups.
  • the auxiliary valve produces a pressure normally equal to the load-sensing pressure increased by a constant, the connection of the chamber 308 with the pipe 102 being replaced by a connection with the line 74.
  • the load-sensing pressure prevail in the chamber 86.11 is also possible, depending on the circumstances, to choose other control pressure than MAX (P) or load-sensing pressure.
  • the advantages of using an auxiliary valve are retained.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fluid-Pressure Circuits (AREA)

Abstract

The hydraulic receivers are fed by one and the same flow rate generator (71), each one being connected thereto through the use of a proportional distributor (170), the system including mean (95, 102, 104), for detecting the maximum of the pressures prevailing upstream of the restriction afforded by the controlled slide valve (3) in the respective proportional distributors, and, in each of these proportional distributors, actuating means cause the compensating slide valve (116) to respond to the maximum of the upstream pressures thus detected. <IMAGE>

Description

L'invention a trait à un ensemble de commande d'une pluralité de récepteurs hydrauliques, à travers lequel les récepteurs sont alimentés par une même génération de débit en y étant chacun relié par l'intermédiaire d'un distributeur proportionnel.The invention relates to a control assembly for a plurality of hydraulic receivers, through which the receivers are supplied by the same generation of flow, each being connected thereto by means of a proportional distributor.

On sait que les distributeurs sont des appareils qu'on dispose entre une génération de débit et un récepteur pour commander le fonctionnement du récepteur en adaptant la façon dont il est connecté à la génération de débit.We know that distributors are devices that are available between a flow generation and a receiver to control the operation of the receiver by adapting the way it is connected to the flow generation.

Les distributeurs du type proportionnel comportent non seulement un tiroir commandé dont la position détermine la section d'un étranglement, mais aussi un tiroir compensateur automatique pour maintenir constante la différence de pression entre l'amont et l'aval de cet étranglement, afin qu'à une position donnée du tiroir commandé corresponde un débit donné de fluide. Par conséquent, lorsqu'un récepteur est commandé avec un distributeur proportionnel, sa vitesse de fonctionnement est fixée par la position du tiroir commandé, indépendamment de la charge que supporte le récepteur.Proportional type distributors include not only a controlled drawer whose position determines the section of a constriction, but also an automatic compensating drawer to maintain constant the pressure difference between the upstream and downstream of this constriction, so that at a given position of the controlled slide corresponds to a given flow of fluid. Consequently, when a receiver is controlled with a proportional distributor, its operating speed is fixed by the position of the controlled drawer, independently of the load that the receiver supports.

Lorsque la génération de débit est utilisée pour alimenter une pluralité de récepteurs à chacun desquels correspond un distributeur proportionnel, il peut arriver que le débit total demandé par les récepteurs excède le débit maximal que la génération de débit est en mesure de fournir. Les tiroirs compensateurs respectifs ne sont alors plus en mesure de maintenir dans chacun des distributeurs la différence de pression entre l'amont et l'aval de l'étranglement à la constante préfixée, de sorte que les récepteurs les plus chargés ralentissent ou s'arrêtent alors que les moins chargés peuvent continuer à fonctionner.When the flow generation is used to supply a plurality of receivers to which each corresponds a proportional distributor, it may happen that the total flow requested by the receivers exceeds the maximum flow that the flow generation is able to supply. The respective compensating drawers are then no longer able to maintain in each of the distributors the pressure difference between the upstream and downstream of the throttling at the prefixed constant, so that the most loaded receivers slow down or stop while the less charged can continue to operate.

Pour éviter ces désordres, on a déjà proposé de tirer parti de la régulation de la génération de débit en fonction de la puissance demandée, qui est à l'heure actuelle prévue sur la plupart des circuits hydrauliques où la génération de débit alimente une pluralité de récepteurs. Cette régulation est réalisée en prévoyant des moyens de détection de charge dits "load-sensing" qui ramènent vers la génération de débit la pression du récepteur le plus chargé, à laquelle pression répond la génération de débit en produisant une pression de service égale à la pression de load-sensing augmentée d'une constante. En réalité, cette constante est rajoutée tant que la demande totale en débit est inférieure à celui capable d'être founi, mais en cas d'excès de la demande, la valeur rajoutée à la pression de load-sensing est plus petite que la constante, et d'autant plus petite que l'excès de demande de débit est important. C'est cette diminution de la valeur rajoutée dont on tire parti pour éviter les désordres précités.To avoid these disorders, it has already been proposed to take advantage of the regulation of the flow generation as a function of the power demanded, which is currently provided on most hydraulic circuits where the flow generation supplies a plurality of receivers. This regulation is carried out by providing load sensing means called "load-sensing" which bring the pressure of the most charged receiver towards the generation of flow, to which pressure responds the generation of flow by producing a working pressure equal to the load-sensing pressure increased by a constant. In reality, this constant is added as long as the total demand for flow is less than that capable of being supplied, but in the event of excess demand, the value added to the load-sensing pressure is smaller than the constant , and the smaller the excess demand for debit is important. It is this reduction in the added value which is used to avoid the abovementioned disorders.

FR-A-2.339.757 propose d'agir sur la pression d'actionnement du tiroir commandé dans chacun des distributeurs proportionnels, en prévoyant que les valves d'actionnement soient alimentées non plus directement à partir d'une pompe pilote, mais avec interposition entre la pompe pilote et les valve d'actionnement d'une soupape de marge de manoeuvre qui fait varier la pression d'alimentation des valves de commande de la même façon que la différence entre la pression de la génération de débit et la pression de load-sensing. Tant que la génération de débit fonctionne normalement, la pression d'alimentation des valves de commande reste constante, de même que si ces valves étaient alimentées directement par la pompe pilote. En cas de demande de débit excessive, la pression d'alimentation des valves de commande va diminuer en fonction de l'importance de l'excès de demande, la pression d'actionnement de tous les tiroirs commandés va diminuer de la même façon, et par conséquent tous les étranglements produits par les tiroirs commandés vont augmenter de la même façon, avec comme résultat que chaque distributeur se verra appliquer le même taux de réduction de débit de sorte que tous les récepteurs vont ralentir avec conservation de leur rapport de vitesse.FR-A-2.339.757 proposes to act on the actuation pressure of the slide controlled in each of the proportional distributors, by providing that the actuation valves are no longer supplied directly from a pilot pump, but with interposition between the pilot pump and the actuation valves of a maneuvering valve which varies the supply pressure of the control valves in the same way as the difference between the pressure of the flow generation and the pressure of load -sensing. As long as the flow generation works normally, the supply pressure of the control valves remains constant, just as if these valves were supplied directly by the pilot pump. In the event of an excessive flow demand, the supply pressure of the control valves will decrease according to the magnitude of the excess demand, the actuation pressure of all the controlled drawers will decrease in the same way, and consequently all the throttles produced by the controlled drawers will increase in the same way, with the result that each distributor will be applied the same rate of reduction of flow so that all the receivers will slow down with conservation of their speed ratio.

FR-A-2.548.290 propose de parvenir au même résultat dans le cas où les distributeurs proportionnels ont un tiroir compensateur qui se trouve en amont du tiroir commandé, en agissant sur les moyens d'actionnement du tiroir ccompensateur : il continue à être sollicité dans le sens de la fermeture par la pression en amont du tiroir commandé et dans le sens de l'ouverture par la pression en aval du tiroir commandé, mais on substitue au ressort classique une double sollicitation de pression, respectivement dans le sens de la fermeture par la pression de load-sensing et dans le sens de l'ouverture par la pression de la génération de débit. La différence de pression entre l'amont et l'aval de l'étranglement du tiroir commandé est ainsi asservie à la différence entre la pression de la génération de débit et la pression de load-sensing, ce qui conduit au résultat précité.FR-A-2.548.290 proposes to achieve the same result in the case where the proportional distributors have a compensating drawer which is located upstream of the controlled drawer, by acting on the actuating means of the compensating drawer: it continues to be used in the direction of closing by the pressure upstream of the controlled drawer and in the direction of opening by the pressure downstream of the controlled drawer, but the conventional spring is replaced by a double pressure stress, respectively in the direction of closing by the load-sensing pressure and in the opening direction by the pressure of the flow generation. The pressure difference between the upstream and downstream of the throttle of the controlled slide is thus controlled by the difference between the pressure of the flow generation and the load-sensing pressure, which leads to the abovementioned result.

L'invention vise à obtenir ce même résultat, mais avec des performances améliorées.The invention aims to obtain this same result, but with improved performance.

Elle propose à cet effet un ensemble de commande d'une pluralité de récepteurs hydrauliques, à travers lequel les récepteurs sont alimentés par une même génération de débit en y étant chacun reliés par l'intermédiaire d'un distributeur proportionnel comportant :

  • - un tiroir commandé dont la position détermine la section d'un premier étranglement ;
  • - un tiroir compensateur pour réguler la différence de pression entre l'amont et l'aval dudit premier étranglement en produisant à l'amont de celui-ci un deuxième étranglement de section appropriée ; et
  • - des moyens d'actionnement du tiroir compensateur, pour lui faire prendre automatiquement une position où il produit ledit deuxième étranglement de section appropriée, en réponse à plusieurs pressions agissant respectivement dans le sens de l'ouverture et dans le sens de la fermeture ;
    • ensemble caractérisé en ce qu'il comporte des moyens pour détecter le maximum des pressions régnant en amont du premier étranglement dans les distributeurs proportionnels respectifs, et en ce que dans chacun de ceux-ci lesdits moyens d'actionnement du tiroir compensateur lu font répondre au maximum des pressions en amont ainsi détecté.
To this end, it offers a control assembly for a plurality of hydraulic receivers, through which the receivers are supplied by the same generation of flow, each being connected thereto by means of a proportional distributor comprising:
  • - a controlled drawer whose position determines the section of a first constriction;
  • - A compensating slide to regulate the pressure difference between the upstream and downstream of said first throttle by producing upstream thereof a second throttle of appropriate section; and
  • - means for actuating the compensating drawer, to make it automatically assume a position where it produces said second throttle of appropriate section, in response to several pressures acting respectively in the opening direction and in the closing direction;
    • assembly characterized in that it comprises means for detecting the maximum of the pressures prevailing upstream of the first throttling in the respective proportional distributors, and in that in each of these said means for actuating the compensating slide read cause the maximum upstream pressures thus detected.

Grâce à ces caractéristiques, on obtient un temps de réponse du tiroir compensateur particulièrement rapide, notamment par rapport à l'état de la technique précité puisque le maximum des pressions en amont des premiers étranglements respectifs est plus élevé que la pression de load-sensing.Thanks to these characteristics, a response time of the compensating drawer is obtained which is particularly rapid, in particular compared to the aforementioned state of the art since the maximum of the pressures upstream of the respective first throttles is higher than the load-sensing pressure.

Selon une première forme préférée de réalisation de l'invention, dans chaque distributeur, lesdits moyens d'actionnement du tiroir compensateur sont prévus pour qu'il soit sollicité :

  • - dans le sens de l'ouverture par la pression en aval du premier étranglement et par la pression en amont du deuxième étranglement ; et
  • - dans le sens de la fermeture par la pression en amont du premier étranglement, par ledit maximum des pressions en amont des premiers étranglements respectifs, et par une force sensiblement constante ;
According to a first preferred embodiment of the invention, in each dispenser, said means for actuating the compensating drawer are provided so that it is requested:
  • - in the direction of opening by the pressure downstream of the first throttle and by the pressure upstream of the second throttle; and
  • - in the direction of closure by the pressure upstream of the first constriction, by said maximum of the pressures upstream of the respective first constrictions, and by a substantially constant force;

ledit ensemble étant ainsi adapté à être utilisé avec une génération de débit produisant une pression de service normalement égale à une pression de régulation qui lui est appliquée, dite load sensing, augmentée d'une constante.said assembly thus being adapted to be used with a generation of flow producing a working pressure normally equal to a regulating pressure which is applied thereto, called load sensing, increased by a constant.

On notera qu'il est essentiel que dans chaque distributeur une force s'applique sur le tiroir compensateur dans le sens de la fermeture : cette force permet de fermer totalement le tiroir compensateur lorsque l'excès de demande de débit est trop important pour que tous les rapports de vitesse entre les récepteurs soient maintenus, ce qui veut dire qu'on arrête alors tous les récepteurs (il y a absence de débit quand le tiroir compensateur est fermé).It will be noted that it is essential that in each distributor a force is applied to the compensating drawer in the closing direction: this force makes it possible to completely close the compensating drawer when the excess demand for flow is too great for all the speed ratios between the receivers are maintained, which means that all receivers are then stopped (there is no flow when the compensating drawer is closed).

De préférence, lesdits moyens d'actionnement du tiroir compensateur comportent : sur celui-ci, une première surface active soumise à la pression en aval du premier étranglement, une deuxième surface active soumise à la pression en amont du deuxième étranglement, une troisième surface active soumise à la pression en amont du premier étranglement, et une quatrième surface active soumise audit maximum des pressions en amont des premiers étranglements respectifs, lesdites première et deuxième surfaces étant opposées auxdites troisième et quatrième surfaces ; ainsi qu'un ressort sollicitant le tiroir compensateur dans le sens de la fermeture.Preferably, said means for actuating the compensating slide comprise: on the latter, a first active surface subjected to pressure downstream of the first throttle, a second active surface subjected to pressure upstream of the second throttle, a third active surface subjected to the pressure upstream of the first constriction, and a fourth active surface subjected to said maximum of the pressures upstream of the respective first constrictions, said first and second surfaces being opposite to said third and fourth surfaces; as well as a spring urging the compensating drawer in the closing direction.

Selon une deuxième forme préférée de réalisation, l'ensemble comporte en outre au moins une valve auxiliaire alimentée par la génération de débit et produisant une pression normalement égale audit maximum des pressions en amont des premiers étranglements respectifs augmente d'une constante, et dans chaque distributeur proportionnel lesdits moyens d'actionnement du tiroir compensateur sont prévus pour qu'il soit sollicité :

  • - dans le sens de l'ouverture par la pression en aval du premier étranglement et par la pression produite par une dite valve auxiliaire ; et
  • - dans le sens de la fermeture par la pression en amont du premier étranglement, par ledit maximum des pressions en amont des premiers étranglements respectifs, et par une force sensiblement constante.
According to a second preferred embodiment, the assembly further comprises at least one auxiliary valve supplied by the generation of flow and producing a pressure normally equal to said maximum of the pressures upstream of the first respective throttles increases by a constant, and in each proportional distributor, said means for actuating the compensating drawer are provided so that it is requested:
  • - in the direction of opening by the pressure downstream of the first throttle and by the pressure produced by a said auxiliary valve; and
  • - In the direction of closing by the pressure upstream of the first constriction, by said maximum of the pressures upstream of the respective first constrictions, and by a substantially constant force.

Cette deuxième forme de réalisation se distingue de la première par la présence de la valve auxiliaire dont la pression produite est appliquée à la place de la pression en amont du deuxième étranglement. Cela permet d'éviter les difficultés qui se produisent lorsque la pression en amont du deuxième étranglement n'est pas la même dans les distributeurs respectifs, par suite de pertes de charges différentes entre la génération de débit et les distributeurs respectifs.This second embodiment differs from the first by the presence of the auxiliary valve, the pressure produced is applied in place of the pressure upstream of the second throttle. This makes it possible to avoid the difficulties which occur when the pressure upstream of the second throttle is not the same in the respective distributors, as a result of different pressure drops between the flow generation and the respective distributors.

En outre, cette forme de réalisation offre l'avantage de pouvoir fournir le résultat visé même si la génération de débit n'est pas régulée en fonction de la charge supportée par les récepteurs.In addition, this embodiment offers the advantage of being able to provide the desired result even if the flow generation is not regulated as a function of the load supported by the receivers.

De préférence, dans chaque distributeur proportionnel, lesdits moyens d'actionnement du tiroir compensateur comportent sur celui-ci une première surface active soumise à la pression en aval du premier étranglement, une deuxième surface active soumise à la pression produite par la valve auxiliaire, une troisième surface active soumise à la pression en amont du premier étranglement, et une quatrième surface active soumise audit maximum des pressions en amont des premiers étranglements respectifs, lesdites première et deuxième surfaces étant opposées auxdites troisième et quatrième surfaces ; ainsi qu'un ressort sollicitant le tiroir compensateur dans le sens de la fermeture.Preferably, in each proportional distributor, said means for actuating the compensating slide comprise thereon a first active surface subjected to the pressure downstream of the first throttle, a second active surface subjected to the pressure produced by the auxiliary valve, a third active surface subjected to the pressure upstream of the first constriction, and a fourth active surface subjected to said maximum of the pressures upstream of the respective first constrictions, said first and second surfaces being opposite to said third and fourth surfaces; as well as a spring urging the compensating drawer in the closing direction.

De préférence, pour des raisons de simplification, lesdites première et troisième surfaces actives du tiroir compensateur ont un dimensionnement similaire, et lesdites deuxième et quatrième surfaces du tiroir compensateur ont un dimensionnement similaire.Preferably, for reasons of simplification, said first and third active surfaces of the compensating drawer have a similar dimensioning, and said second and fourth surfaces of the compensating drawer have a similar dimensioning.

De préférence, ladite valve auxiliaire comporte :

  • - une chambre d'alimentation reliée à la génération de débit ;
  • - une chambre de régulation dans laquelle règne ledit maximum des pressions en amont des premiers étranglements respectifs ;
  • - une chambre de sortie où règne ladite pression produite ;
  • - un tiroir dont la position détermine la section d'un étranglement entre la chambre d'alimentation et la chambre de sortie, comportant une première surface active disposée dans la chambre de régulation de sorte que ledit maximum des pressions en amont des premiers étranglements respectifs agit dans le sens de l'ouverture, et une deuxième surface active disposée dans la chambre de sortie de sorte que la pression produite agit dans le sens de la fermeture ; et
  • - un ressort, qui agit sur le tiroir dans le sens de l'ouverture.
Preferably, said auxiliary valve comprises:
  • - a supply chamber connected to the flow generation;
  • a regulation chamber in which said maximum of pressures prevails upstream of the first respective throttles;
  • - an outlet chamber where said pressure produced prevails;
  • a drawer, the position of which determines the section of a constriction between the supply chamber and the outlet chamber, comprising a first active surface arranged in the regulation chamber so that said maximum of the pressures upstream of the respective first constrictions acts in the direction of opening, and a second active surface disposed in the outlet chamber so that the pressure produced acts in the direction of closing; and
  • - a spring, which acts on the drawer in the opening direction.

Dans le cas où les distributeurs proportionnels sont répartis en plusieurs groupes d'un distributeur ou de plusieurs distributeurs voisins, les groupes étant distants les uns des autres, il est préférable que l'ensemble comporte pour chaque groupe une dite valve auxiliaire voisine du groupe.In the case where the proportional distributors are divided into several groups of a distributor or of several neighboring distributors, the groups being distant from each other, it is preferable that the assembly comprises for each group a so-called auxiliary valve neighboring the group.

On évite ainsi les problèmes liés aux pertes de charge en ligne, et surtout d'avoir à prévoir une ligne entre la valve auxiliaire et un groupe de distributeurs éloigné de celle-ci.This avoids the problems associated with line pressure drops, and above all having to provide a line between the auxiliary valve and a group of distributors remote from the latter.

De préférence, dans chaque distributeur proportionnel il y a absence de clapet de non-retour entre lesdits deuxième étranglement et premier étranglement.Preferably, in each proportional distributor there is no non-return valve between said second throttle and first throttle.

En effet, l'invention, au moins dans les deux formes de réalisation exposées précédemment, rend inutile ce clapet de non-retour prévu dans tous les distributeurs proportionnels antérieurs. Cela provient du fait qu'on est sûr qu'au repos (quand tous les tiroirs commandés sont au neutre), tous les tiroirs compensateurs sont fermés : si l'on fait l'inventaire des sollicitations qui s'appliquent dans le sens de la fermeture et de celles qui s'appliquent dans le sens de l'ouverture, en tenant compte du fait qu'au repos la pression en aval de chaque tiroir compensateur est égale à la pression en amont (même si le tiroir compensateur est fermé, à cause des fuites infimes inévitables), on voit que les efforts qui s'appliquent dans le sens de la fermeture sont toujours supérieurs à ceux s'appliquant dans le sens de l'ouverture.Indeed, the invention, at least in the two embodiments described above, makes this check valve provided in all prior proportional distributors unnecessary. This stems from the fact that we are sure that at rest (when all the ordered drawers are neutral), all the compensating drawers are closed: if we make an inventory of the stresses that apply in the direction of closing and those which apply in the opening direction, taking into account that at rest the pressure downstream of each compensating slide is equal to the pressure upstream (even if the compensating slide is closed, at because of the inevitable tiny leaks), it can be seen that the forces which apply in the direction of closing are always greater than those which apply in the direction of opening.

Selon des caractéristiques préférées de l'invention, lesdits moyens pour détecter le maximum des pressions en amont des premiers étranglements respectifs comportent une canalisation commune fermée à une première extrémité et débouchant dans le réservoir à travers une restriction à une deuxième extrémité ; et pour chaque distributeur proportionnel un clapet de non-retour disposé passant entre l'amont du premier étranglement et la conduite commune.According to preferred features of the invention, said means for detecting the maximum of the pressures upstream of the first respective throttles comprise a common pipe closed at a first end and opening into the tank through a restriction at a second end; and for each proportional distributor a non-return valve arranged passing between the upstream of the first throttle and the common pipe.

Ces caractéristiques sont en effet favorables sur le plan de la rapidité de réponse des tiroirs compensateurs.These characteristics are indeed favorable in terms of the speed of response of the compensating drawers.

L'exposé de l'invention sera maintenant poursuivi par la description d'exemples de réalisation, donnée ci-après à titre illustratif et non limitatif, en référence aux dessins annexés, sur lesquels :

  • - la figure 1 est une vue schématique en coupe d'un distributeur proportionnel faisant partie d'un ensemble conforme à l'invention ;
  • - la figure 2 est un schéma d'un circuit hydraulique comprenant cet ensemble de commande, qui comporte deux distributeurs similaires à celui montré sur la figure 1, accollés bout à bout ; et
  • - les figures 3 et 4 sont semblables aux figures 1 et 2 respectivement, mais pour une variante de réalisation.
The description of the invention will now be continued with the description of exemplary embodiments, given below by way of illustration and not limitation, with reference to the appended drawings, in which:
  • - Figure 1 is a schematic sectional view of a proportional distributor forming part of an assembly according to the invention;
  • - Figure 2 is a diagram of a hydraulic circuit comprising this control assembly, which comprises two distributors similar to that shown in Figure 1, joined end to end; and
  • - Figures 3 and 4 are similar to Figures 1 and 2 respectively, but for an alternative embodiment.

Le distributeur 70 illustré sur la figure 1 est similaire à celui décrit dans FR-A-2.562.632, à l'exception de son dispositif compensateur de pression.The distributor 70 illustrated in FIG. 1 is similar to that described in FR-A-2,562,632, with the exception of its pressure compensating device.

Il comporte un bloc statorique 1, dans l'alésage 2 duquel coulisse un tiroir commandé cylindrique 3. A la manière habituelle, la commutation des circuits hydrauliques s'effectue par déplacement des gorges du tiroir 3 devant des lumières du stator.It comprises a stator block 1, in the bore 2 of which slides a cylindrical controlled drawer 3. In the usual way, the switching of the hydraulic circuits is effected by displacement of the grooves of the drawer 3 in front of the lights of the stator.

A son extrémité gauche, par exemple, le tiroir 3 est pourvu d'un dispositif de rappel par ressort de type connu, comprenant un ressort hélicoïdal 4, comprimé entre les épaulements 5 et 6 de deux bagues 7 et 8, prisonnières entre deux épaulements de l'extrémité 9 du tiroir 3, autour de laquelle elles peuvent coulisser. Ainsi, le tiroir 3 est spontanément rappelé à une position neutre de repos, tandis qu'il est poussé à droite (figure 1) lorsqu'on envoie une pression de pilotage dans une ouverture 10 du chapeau fixe 61. Au contraire, il est poussé vers la gauche lorsqu'une pression de pilotage est envoyée à l'opposé, dans une ouverture 11 du chapeau 62 de son autre extrémité. Dans l'exemple illustré, on a supposé que le tiroir à trois positions 3 est utilisé pour assurer la commande d'un vérin hydraulique double effet 12. Pour cela, l'une des sections du vérin 12 est reliée à un premier canal d'utilisation 13 du stator 1, alors que la section opposée du vérin 12 est reliée à une seconde canalisation d'utilisation 14 du stator 1.At its left end, for example, the drawer 3 is provided with a spring return device of known type, comprising a helical spring 4, compressed between the shoulders 5 and 6 of two rings 7 and 8, trapped between two shoulders of the end 9 of the drawer 3, around which they can slide. Thus, the drawer 3 is spontaneously returned to a neutral rest position, while it is pushed to the right (FIG. 1) when a pilot pressure is sent into an opening 10 of the fixed cap 61. On the contrary, it is pushed to the left when a pilot pressure is sent opposite, in an opening 11 of the cap 62 at its other end. In the example illustrated, it has been assumed that the three-position slide 3 is used to control a double-acting hydraulic cylinder 12. For this, one of the sections of the cylinder 12 is connected to a first channel use 13 of the stator 1, while the opposite section of the jack 12 is connected to a second use pipe 14 of the stator 1.

Le distributeur reçoit dans une chambre annulaire 15, la pression envoyée par une génération de débit 71.The distributor receives in an annular chamber 15, the pressure sent by a generation of flow 71.

La chambre d'alimentation 15 entoure un tiroir compensateur 16, dit aussi balance, qui est mobile dans un alésage 80 du stator 1, et qui comporte une gorge 81 qui produit, en fonction de la position du tiroir 16, un étranglement plus ou moins important entre la chambre 15 et une chambre annulaire 27 entourant la partie centrale du tiroir commandé 3.The supply chamber 15 surrounds a compensating drawer 16, also called a balance, which is movable in a bore 80 of the stator 1, and which has a groove 81 which produces, depending on the position of the drawer 16, a more or less constriction. important between the chamber 15 and an annular chamber 27 surrounding the central part of the controlled drawer 3.

A chacune de ses deux extrémités, le tiroir commandé 3 comporte un logement intérieur axial, 28 à gauche, 29 à droite.At each of its two ends, the controlled slide 3 has an axial internal housing, 28 on the left, 29 on the right.

Le logement 28 communique avec l'extérieur du tiroir par deux perçages radiaux référencés respectivement 30 et 31. De même, le logement 29 débouche sur deux perçages radiaux 32 et 33.The housing 28 communicates with the outside of the drawer by two radial bores referenced respectively 30 and 31. Likewise, the housing 29 opens onto two radial bores 32 and 33.

Lorsque le tiroir 3 est à sa position neutre de repos, le perçage 30 fait face à une partie pleine 34 du stator qui l'obture, entre deux chambres annulaires 35 et 36. La chambre 35 communique avec la première canalisation d'utilisation 13, alors que la chambre 36 est raccordée au circuit de retour.When the drawer 3 is in its neutral rest position, the bore 30 faces a solid part 34 of the stator which closes it, between two annular chambers 35 and 36. The chamber 35 communicates with the first use pipe 13, while room 36 is connected to the return circuit.

De même, le perçage 32 est obturé au repos, par une partie pleine 37, située entre deux chambres annulaires 38 et 39. La chambre 38 communique avec la seconde canalisation d'utilisation 14, alors que la chambre 39 est reliée au circuit de retour.Similarly, the bore 32 is closed at rest, by a solid part 37, located between two annular chambers 38 and 39. The chamber 38 communicates with the second use pipe 14, while the chamber 39 is connected to the return circuit .

Entre les perçages 30 et 31, le stator définit, dans l'alésage, une partie pleine 40, devant laquelle est susceptible de se déplacer une gorge 41 du tiroir 3.Between the holes 30 and 31, the stator defines, in the bore, a solid part 40, in front of which is capable of moving a groove 41 of the drawer 3.

Autour du tiroir 3, dans la zone située autour du perçage 31 lorsque le tiroir 3 est poussé à droite (figure 1), se trouve une chambre statorique annulaire 42.Around the drawer 3, in the zone situated around the bore 31 when the drawer 3 is pushed to the right (FIG. 1), there is an annular stator chamber 42.

De même, à son extrémité opposée, le tiroir 3 possède une gorge 43 mobile devant une partie pleine 44 du stator. Autour du passage 33 lorsque le tiroir 3 est repoussé vers la gauche, se trouve une chambre statorique annulaire 45.Similarly, at its opposite end, the drawer 3 has a groove 43 movable in front of a solid part 44 of the stator. Around the passage 33 when the drawer 3 is pushed to the left, there is an annular stator chamber 45.

Les deux chambres 42 et 45 sont reliées par une canalisation 46 dite canalisation de load sensing.The two chambers 42 and 45 are connected by a pipe 46 called the load sensing pipe.

Des encoches de progressivité équipent les différentes gorges du tiroir, comme indiqué par exemple par les références 48, 49, 50, 51.Progressivity notches equip the different grooves of the drawer, as indicated for example by the references 48, 49, 50, 51.

Enfin, un premier clapet de gavage 52 est monté en parallèle sur la première canalisation d'utilisation 13. De même, un clapet de gavage 53 est monté en parallèle sur la seconde canalisation d'utilisation 14. Derrière les clapets 52 et 53, se trouve une chambre 54 reliée au circuit de retour d'huile.Finally, a first booster valve 52 is mounted in parallel on the first use pipe 13. Similarly, a booster valve 53 is mounted in parallel on the second user pipe 14. Behind the valves 52 and 53, is finds a chamber 54 connected to the oil return circuit.

Un clapet de surpression, respectivement 55 et 56, est prévu sur le côté de chacune des canalisations d'utilisation 13,14, qui peuvent ainsi se déverserdans les chambres de retour, respectivement 36, 39.A pressure relief valve, respectively 55 and 56, is provided on the side of each of the use pipes 13, 14, which can thus flow into the return chambers, respectively 36, 39.

Le fonctionnement du tiroir commandé 3 va maintenant être décrit.The operation of the controlled drawer 3 will now be described.

En position neutre, les chambres 27, 35 et 38 sont obturés, de sorte que le vérin 12 est immobilisé alors qu'aucun débit ne passe dans le distributeur. En outre, la canalisation 46 communique par les gorges 41 et 43 respectivement avec la chambre 36 et la chambre 39, c'est-à-dire qu'elle est raccordée au circuit de retour.In the neutral position, the chambers 27, 35 and 38 are closed, so that the jack 12 is immobilized while no flow passes through the distributor. In addition, the pipe 46 communicates through the grooves 41 and 43 respectively with the chamber 36 and the chamber 39, that is to say that it is connected to the return circuit.

Lorsqu'une pression de pilotage est envoyée par l'ouverture 10, comme c'est le cas sur la figure 1, le tiroir 3 coulisse vers la droite avec une amplitude déterminée par la valeur de la pression de pilotage, qui s'équilibre avec la poussée antagoniste du ressort 4, plus ou moins comprimé. La pression d'alimentation de la chambre 27 est envoyée dans la canalisation 13 en passant par la gorge 49 et la chambre 35, alors que la canalisation 14 communique avec la chambre de retour 39 par la gorge 51. Chacune des gorges 49 et 51 détermine un étranglement dont la section est déterminée par la position du tiroir 3. En outre, la canalisation 46 communique à gauche avec la canalisation 13 par les passages 31, 28 et 30, tandis qu'à droite elle est obturée. La pression en aval de l'étranglement procuré par la gorge 49 est ainsi transmise à la canalisation 46.When a pilot pressure is sent through the opening 10, as is the case in FIG. 1, the slide 3 slides to the right with an amplitude determined by the value of the pilot pressure, which is balanced with the opposing thrust of the spring 4, more or less compressed. The supply pressure of the chamber 27 is sent into the line 13 through the groove 49 and the chamber 35, while the line 14 communicates with the return chamber 39 through the groove 51. Each of the grooves 49 and 51 determines a throttle whose section is determined by the position of the slide 3. In addition, the pipe 46 communicates on the left with the pipe 13 through the passages 31, 28 and 30, while on the right it is closed. The pressure downstream of the throttle provided by the groove 49 is thus transmitted to the pipe 46.

Lorsqu'une pression de pilotage est envoyée par l'ouverture 11, le tiroir 3 coulisse vers la gauche jusqu'à une position déterminée par l'amplitude de la pression de pilotage. La pression d'alimentation de la chambre 27 est envoyée dans la canalisation 14 en passant par la gorge 50 et la chambre 38, alors que la canalisation 13 communique avec la chambre de retour 36 en passant par la gorge 48. Chacune des gorges 48 et 50 détermine un étranglement dont la section est déterminée par la position du tiroir 3. En outre, la canalisation 46 communique à droite avec la canalisation 14 par les perçages 33, 29 et 32, tandis qu'à gauche elle est obturée. La pression en aval de l'étranglement procurée par la gorge 50 est ainsi transmise à la canalisation 46.When a pilot pressure is sent through the opening 11, the slide 3 slides to the left to a position determined by the amplitude of the pilot pressure. The supply pressure of the chamber 27 is sent into the line 14 passing through the groove 50 and the chamber 38, while the line 13 communicates with the return chamber 36 through the groove 48. Each of the grooves 48 and 50 determines a constriction, the section of which is determined by the position of the drawer 3. In addition, the pipe 46 communicates on the right with the pipe 14 by the holes 33, 29 and 32, while on the left it is closed. The pressure downstream of the throttle provided by the groove 50 is thus transmitted to the pipe 46.

On voit ainsi qu'en position neutre, la canalisation 46 est mise à la pression du circuit de retour, tandis que dans chacune des positions de travail, elle est portée à la pression en aval de l'étranglement procuré par le tiroir 3 sur la ligne d'alimentation du vérin 12, c'est-à-dire à la pression d'utilisation de celui-ci.It can thus be seen that in the neutral position, the pipe 46 is put under the pressure of the return circuit, while in each of the working positions, it is brought to the pressure downstream of the throttle provided by the slide 3 on the cylinder 12 supply line, that is to say the operating pressure thereof.

Le sélecteur de circuit 99 (dit aussi fonction OU) a l'une de ses entrées qui communique avec la canalisation 46 par un canal 72, et son autre entrée qui communique avec un canal 73 relié à la canalisation de sortie du sélecteur de circuit d'un distributeur similaire. Ici, la pression dans la canalisation 46 est la plus forte, de sorte que le sélecteur de circuit 99 adopte la position illustrée où il transmet par sa sortie à la canalisation 74 la pression d'utilisation du vérin 12, qui est la pression d'utilisation la plus élevée de l'ensemble des récepteurs qu'alimente la génération de débit 71. Plus généralement, comme cela apparaît clairement sur la figure 2, c'est toujours la pression du récepteur le plus chargé qui est appliquée à la canalisation 74, cette pression dite de load sensing étant transmise à la génération de débit 71 qui produit une pression de service normalement égale à la pression de load sensing augmentée d'une constante.The circuit selector 99 (also called OR function) has one of its inputs which communicates with the pipe 46 by a channel 72, and its other input which communicates with a channel 73 connected to the output pipe of the circuit selector d '' a similar distributor. Here, the pressure in the line 46 is the highest, so that the circuit selector 99 adopts the illustrated position where it transmits by its output to the line 74 the operating pressure of the cylinder 12, which is the pressure of highest use of all the receivers supplied by the flow generation 71. More generally, as it can be seen clearly in FIG. 2, it is always the pressure of the most loaded receiver which is applied to the pipe 74, this so-called load sensing pressure being transmitted to the generation of flow 71 which produces an operating pressure normally equal to the load sensing pressure increased by a constant.

Dans la position illustrée sur la figure 1, le tiroir compensateur 16 ferme le passage entre les chambres 15 et 27, mais lorsqu'il se déplace vers la gauche il produit, en fonction de sa position, un étranglement plus ou moins important en amont de l'étranglement procuré par le tiroir 3 sur la ligne d'alimentation du vérin 12.In the position illustrated in FIG. 1, the compensating slide 16 closes the passage between the chambers 15 and 27, but when it moves to the left it produces, depending on its position, a more or less significant constriction upstream of the throttle provided by the slide 3 on the supply line of the jack 12.

Le tiroir 16 comporte une première surface active 82 soumise à la pression en aval de l'étranglement procuré par le tiroir 3, une deuxième surface active 83 soumise à la pression en amont de l'étranglement procuré par le tiroir 16, une troisième surface active 84 soumise à la pression en amont de l'étranglement procuré par le tiroir 3, et une quatrième surface active 85 soumise à la pression régnant dans une chambre 86 située à gauche du tiroir 16.The slide 16 has a first active surface 82 subjected to the pressure downstream of the throttle provided by the slide 3, a second active surface 83 subjected to the pressure upstream of the throttle provided by the slide 16, a third active surface 84 subjected to the pressure upstream of the throttle provided by the drawer 3, and a fourth active surface 85 subjected to the pressure prevailing in a chamber 86 located to the left of the drawer 16.

Les surfaces 82 et 83 regardent vers la droite, et sont opposés aux surfaces 84 et 85 qui regardent vers la gauche. Etant donné que le tiroir 16 ferme l'étranglement qu'il procure lorsqu'il se déplace de la gauche vers la droite et vice-versa, les pressions auxquelles sont soumises les surfaces 82 et 83 sollicitent le tiroir 16 dans le sens de l'ouverture tandis que les pressions auxquelles sont soumises les surfaces 84 et 85 le sollicitent dans le sens de la fermeture. Un ressort 87 est prévu dans la chambre 86 entre le fond de celle-ci, situé à gauche, et la surface 85, ce qui fait que le tiroir 16 est également sollicité dans le sens de la fermeture par une force sensiblement constante. Pour régler celle-ci, il est prévu une vis 88 qui forme le fond de la chambre 86.The surfaces 82 and 83 look to the right, and are opposed to the surfaces 84 and 85 which look towards the left. Since the drawer 16 closes the constriction which it produces when it moves from the left to the right and vice versa, the pressures to which the surfaces 82 and 83 are subjected urge the drawer 16 in the direction of the opening while the pressures to which the surfaces 84 and 85 are subjected urge it in the closing direction. A spring 87 is provided in the chamber 86 between the bottom of the latter, located on the left, and the surface 85, which means that the slide 16 is also biased in the closing direction by a substantially constant force. To adjust the latter, a screw 88 is provided which forms the bottom of the chamber 86.

La surface 82 est soumise à la pression régnant en aval de l'étranglement procuré par le tiroir 3 parce qu'elle est disposée dans une chambre 89 communiquant avec la canalisation 46 par un conduit 90, et la surface 84 est soumise à la pression régnant en amont de l'étranglement procuré par le tiroir 3 parce qu'elle est disposée dans une chambre 91 communiquant avec la chambre 27 par un conduit 92.The surface 82 is subjected to the pressure prevailing downstream of the throttle provided by the slide 3 because it is disposed in a chamber 89 communicating with the pipe 46 by a conduit 90, and the surface 84 is subjected to the prevailing pressure upstream of the constriction provided by the drawer 3 because it is disposed in a chamber 91 communicating with the chamber 27 by a conduit 92.

Le tiroir 16 est pourvu d'un perçage radial 93 communiquant avec un perçage axial borgne 94 qui débouche sur un siège susceptible d'être obturé ou démasqué par une bille 95 dont le ressort de rappel 96 se trouve comprimé dans une chambre 98 qui débouche par une ouverture axiale 100 dans la chambre 86. Celle-ci communique par un passage 101 avec une canalisation 102 fermée à une extrémité et débouchant dans le réservoir de la génération de débit à travers une restriction 104 à l'autre extrémité, la canalisation 102 étant commune à tous les distributeurs, qui ont leur chambre correspondant à 86 qui y est reliée.The drawer 16 is provided with a radial bore 93 communicating with a blind axial bore 94 which opens onto a seat capable of being closed off or unmasked by a ball 95 whose return spring 96 is compressed in a chamber 98 which opens out an axial opening 100 in the chamber 86. This communicates via a passage 101 with a pipe 102 closed at one end and opening into the flow generation reservoir through a restriction 104 at the other end, the pipe 102 being common to all distributors, who have their room corresponding to 86 which is connected to it.

La figure 2 montre un ensemble de commande conforme à l'invention, formé d'un seul groupe de deux distributeurs accolés, respectivement le distributeur 70 illustré sur la figure 1, et un distributeur identique 70', tous les éléments de ce dernier portant la même référence que le distributeur 70, mais affectée d'un indice prime.FIG. 2 shows a control assembly according to the invention, formed of a single group of two contiguous distributors, respectively the distributor 70 illustrated in FIG. 1, and an identical distributor 70 ', all the elements of the latter carrying the same reference as distributor 70, but assigned a prime index.

On voit que pour chaque distributeur 70 et 70', la canalisation commune 102 est reliée à l'amont de l'étranglement procuré par le tiroir 3 par l'intermédiaire d'un clapet de non-retour dont la bille 95 forme l'obturateur, ce clapet de non-retour étant passant vers la canalisation 102. Il règne par conséquent dans celle-ci la plus haute des pressions régnant en amont des étranglements procurés par les tiroirs 3 et 3', la restriction 104 réalisant une décompression de la conduite 102 qui permet l'ajustement continu de celle-ci au maximum des pressions en amont des tiroirs 3 et 3'. C'est donc cette dernière pression qui règne dans la chambre 86 et dans la chambre correspondante du distributeur 70'.We see that for each distributor 70 and 70 ', the common pipe 102 is connected upstream of the throttle provided by the drawer 3 by means of a non-return valve whose ball 95 forms the shutter , this non-return valve being passing towards the pipe 102. Consequently, there prevails in the latter the pressures prevailing upstream of the throttles provided by the drawers 3 and 3 ′, the restriction 104 achieving a decompression of the pipe. 102 which allows the continuous adjustment thereof to the maximum of the pressures upstream of the drawers 3 and 3 '. It is therefore this last pressure which prevails in the chamber 86 and in the corresponding chamber of the distributor 70 '.

Dans l'exemple illustré, les surfaces 82 et 84 ont un dimensionnement similaire, noté S2, et les surfaces 83 et 85 ont un dimensionnement similaire, noté S1. Si l'on note en outre F la force appliquée par le ressort 87, P la pression régnant en amont de l'étranglement procuré par le tiroir commandé 3, MAX(P) le maximum des pressions régnant en amont de l'étranglement procuré par les tiroirs commandés, PU la pression régnant en aval de l'étranglement procuré par le tiroir commandé 3, et P la pression régnant en amont de l'étranglement procuré par le tiroir compensateur 16, on démontre qu'à l'équilibre :In the example illustrated, the surfaces 82 and 84 have a similar dimensioning, denoted S 2 , and the surfaces 83 and 85 have a similar dimensioning, denoted S 1 . If we also note F the force applied by the spring 87, P the pressure prevailing upstream of the throttle provided by the controlled slide 3, MAX (P) the maximum of the pressures prevailing upstream of the throttle provided by the controlled drawers, PU the pressure prevailing downstream of the throttle provided by the controlled slide 3, and P the pressure prevailing upstream of the throttle provided by the compensating slide 16, it is shown that at equilibrium:

Figure imgb0001
Figure imgb0001

On voit que la différence de pression Pl- PU dépend de la différence de pression P - MAX(P) suivant une fonction linéaire à coefficient strictement positif et à constante strictement négative.We see that the pressure difference P l - PU depends on the pressure difference P - MAX (P) according to a linear function with strictly positive coefficient and strictly negative constant.

Compte tenu de la façon dont est régulée la génération de débit, la différence de pression P - MAX(P) reste constante tant que la génération de débit est en mesure de satisfaire à la demande totale en débit, tandis qu'elle est inférieure à cette constante lorsqu'il y a excès de demande en débit, la diminution étant d'autant plus forte que l'excès de demande l'est.Given the way the flow generation is regulated, the pressure difference P - MAX (P) remains constant as long as the flow generation is able to satisfy the total demand for flow, while it is less than this constant when there is excess demand for flow, the decrease being all the greater the excess demand is.

Les valeurs S1, S2 et F sont choisies notamment en fonction des impératifs suivants :

  • - le tiroir 16 doit assurer en service normal, où P
  • - MAX(Pi) = a, une valeur b à Pi- PU de sorte que :
    Figure imgb0002
  • - le tiroir 16 doit se fermer pour une certaine valeur minimum c de P - MAX(Pi), en deçà de laquelle on estime que la surcharge est trop importante pour que les rapports de vitesse entre les récepteurs puissent être maintenus, de sorte que :
    Figure imgb0003
The values S 1 , S 2 and F are chosen in particular according to the following requirements:
  • - the drawer 16 must ensure in normal service, where P
  • - MAX (P i ) = a, a value b to P i - PU so that:
    Figure imgb0002
  • - the slide 16 must close for a certain minimum value c of P - MAX (P i ), below which it is estimated that the overload is too great for the speed ratios between the receivers to be maintained, so that :
    Figure imgb0003

On notera qu'il n'y a pas de clapet de non-retour dans le distributeur 70 entre les chambres 15 et 27, contrairement aux distributeurs proportionnels classiques où il est toujours prévu un clapet de non-retour disposé passant entre l'étranglement procuré par le tiroir compensateur et celui procuré par le tiroir commandé.Note that there is no non-return valve in the distributor 70 between the chambers 15 and 27, unlike conventional proportional distributors where there is always a non-return valve arranged passing between the throttle provided by the compensating drawer and that provided by the ordered drawer.

En effet, dans l'ensemble de commande, on est sûr qu'au repos, quand tous les tiroirs commandés 3 sont au neutre, que tous les tiroirs compensateurs 16 sont dans la position de fermeture illustrée : si l'on garde les mêmes notations que précédemment, en observant qu'au repos P = P dans tous les distributeurs, même si le tiroir 16 est fermé compte tenu des fuites infimes entre l'amont et l'aval de celui-ci qui sont inévitables, on voit que le tiroir 16 est sollicité dans le sens de la fermeture par :

Figure imgb0004

et dans le sens de l'ouverture par :
Figure imgb0005
 Indeed, in the control assembly, it is certain that at rest, when all the controlled drawers 3 are neutral, that all the compensating drawers 16 are in the closed position illustrated: if the same notations are kept as before, by observing that at rest P = P in all the distributors, even if the drawer 16 is closed taking into account the minute leaks between the upstream and the downstream thereof which are inevitable, we see that the drawer 16 is requested in the closing direction by:
Figure imgb0004
and in the direction of opening by:
Figure imgb0005

Etant donné que F + P.S2 est strictement positif, on est sûr que les forces agissant dans le sens de la fermeture seront toujours supérieures à celles agissant dans le sens de l'ouverture.Since F + PS 2 is strictly positive, it is certain that the forces acting in the direction of closing will always be greater than those acting in the direction of opening.

Dans une variante non illustrée de l'invention, on se sert de la pression MAX(P) régnant dans la canalisation 102 pour réguler la génération de débit, au lieu de la pression de load-sensing régnant dans la canalisation 74. Cette variante est moins intéressante que celle illustrée, étant donné qu'il est moins facile de réguler une génération de débit lorsque la différence entre la pression de régulation et la pression de service devient plus petite.In a variant not illustrated of the invention, the pressure MAX (P) prevailing in the pipe 102 is used to regulate the generation of flow rate, instead of the load-sensing pressure prevailing in the pipe 74. This variant is less interesting than that illustrated, since it is less easy to regulate a flow generation when the difference between the regulating pressure and the operating pressure becomes smaller.

Dans d'autres variantes non illustrées, on remplace la détection de la pression de load-sensing avec des sélecteurs de circuit par une détection avec des clapets de non-retour, ou la détection de MAX(P) avec des clapets de non-retour par une détection avec des sélecteurs de circuit.In other variants not illustrated, we replace the detection of the load-sensing pressure with circuit selectors by a detection with non-return valves, or the detection of MAX (P) with non-return valves by detection with circuit selectors.

Il apparaît toutefois que la solution illustrée où la détection de la pression de load-sensing se fait par des sélecteurs de circuit tandis que celle de MAX(P) se fait par des clapets de non-retour est préférable, étant donné qu'il est souhaitable d'avoir des temps de réponse rapides pour le tiroir compensateur 16 (pour réagir rapidement à toutes variations de charge), tandis qu'il vaut mieux avoir des temps de réponse plus lents pour la régulation de la génération de débit (afin d'éviter de changer sans arrêt le régime de celle-ci).It appears however that the illustrated solution where the detection of the load-sensing pressure is done by circuit selectors while that of MAX (P) is done by non-return valves is preferable, since it is desirable to have quick response times for the compensating slide 16 (to react quickly to any load variations), while it is better to have slower response times for regulating the flow generation (in order to avoid constantly changing the diet).

On notera que les canalisations 73 et 74 forment avec le sélecteur 99 un ensemble qui traverse tout le distributeur 70, et qu'il en est de même pour la canalisation 102, de sorte qu'on a la possibilité d'effectuer les raccordements entre distributeurs, en accolant simplement ces derniers bout à bout, ce qui est d'ailleurs illustré de façon complète sur la figure 2.It will be noted that the pipes 73 and 74 form with the selector 99 an assembly which crosses the entire distributor 70, and that it is the same for the pipe 102, so that it is possible to make the connections between distributors , by simply joining the latter end to end, which is moreover illustrated completely in FIG. 2.

Dans la variante de l'ensemble de commande selon l'invention montrée sur les figures 3 et 4, on a gardé les mêmes références numériques pour les éléments identiques tandis qu'on leur a additionné le chiffre 100 pour les éléments similaires.In the variant of the control assembly according to the invention shown in FIGS. 3 and 4, the same reference numbers have been kept for the identical elements while the number 100 has been added to them for similar elements.

Le distributeur proportionnel 170 montré sur la figure 3 comporte un tiroir compensateur 116 dont la partie droite est différente de celle du tiroir 16 : elle comporte en regard de la surface active 83 une surface active 300 ayant la même valeur efficace, c'est-à-dire S1, une autre surface active 301 est soumise à la pression en aval de l'étranglement procuré par le tiroir 3, et encore une autre surface active 302 est soumise à la pression produite par une valve auxiliaire 303.The proportional distributor 170 shown in FIG. 3 comprises a compensating drawer 116, the straight part of which is different from that of the drawer 16: it comprises, opposite the active surface 83, an active surface 300 having the same effective value, that is to say say S 1 , another active surface 301 is subjected to the pressure downstream of the throttle provided by the slide 3, and yet another active surface 302 is subjected to the pressure produced by an auxiliary valve 303.

Les surfaces 301 et 302 regardent vers la droite, elles sont donc opposées aux surfaces 84 et 85, les pressions auxquelles elles sont soumises sollicitant donc le tiroir 116 dans le sens de l'ouverture.The surfaces 301 and 302 look to the right, they are therefore opposed to the surfaces 84 and 85, the pressures to which they are subjected therefore urge the drawer 116 in the direction of opening.

La surface 301 est soumise à la pression régnant en aval de l'étranglement procuré par le tiroir 3 parce qu'elle est disposée dans la canalisation 146, et la surface 302 est soumise à la pression produite par la valve 303 parce qu'elle est disposée dans une chambre 304 reliée par une canalisation 305 à la valve 303.The surface 301 is subjected to the pressure prevailing downstream of the throttle provided by the slide 3 because it is disposed in the pipe 146, and the surface 302 is subjected to the pressure produced by the valve 303 because it is disposed in a chamber 304 connected by a pipe 305 to the valve 303.

La surface active 301 a une valeur efficace similaire à celle de la surface 84, c'est-à-dire S2, et la surface 302 a une valeur efficace similaire à celle de la surface 85, c'est-à-dire S1.The active surface 301 has an effective value similar to that of the surface 84, i.e. S 2 , and the surface 302 has an effective value similar to that of the surface 85, i.e. S 1 .

Etant donné que les surfaces 83 et 300 ont également un dimensionnement similaire, la pression régnant dans la chambre 15 n'a pas d'influence sur la position qu'adopte le tiroir 116.Since the surfaces 83 and 300 also have a similar dimensioning, the pressure prevailing in the chamber 15 has no influence on the position adopted by the drawer 116.

Compte tenu de la disposition et du dimensionnement des surfaces 301 et 302, on a en fait remplacé l'action de la pression en amont de l'étranglement procuré par le tiroir compensateur par l'action de la pression produite par la valve annexe 303.Given the arrangement and dimensioning of surfaces 301 and 302, the action of the pressure upstream of the throttle provided by the compensating slide has in fact been replaced by the action of the pressure produced by the annex valve 303.

A condition d'opérer le changement de notation correspondant, les équations données précédemment s'appliquent donc à la variante montrée sur les figures 3 et 4.Provided the corresponding notation is changed, the equations given above therefore apply to the variant shown in Figures 3 and 4.

La valve auxiliaire 303 comporte un corps statorique 306 qui définit une chambre d'alimentation 307 reliée à l'orifice de refoulement de la génération de débit 71 ; une chambre de régulation 308 dans laquelle règne MAX(P;) ; une chambre de sortie 309 où règne ladite pression produite ; un tiroir 310 dont la position détermine grâce à une gorge 311 la section d'un étranglement entre les chambres 307 et 309 ; et un ressort 312 qui agit sur le tiroir 310 dans le sens de l'ouverture, une vis 313 étant prévue pour régler la force avec laquelle agit le ressort.The auxiliary valve 303 comprises a stator body 306 which defines a supply chamber 307 connected to the discharge orifice of the flow generation 71; a regulation chamber 308 in which MAX (P ; ) prevails; an outlet chamber 309 where said pressure produced prevails; a drawer 310 whose position determines, thanks to a groove 311, the section of a constriction between the chambers 307 and 309; and a spring 312 which acts on the slide 310 in the opening direction, a screw 313 being provided to adjust the force with which the spring acts.

Il règne MAX(P) dans la chambre 308 parce que cette chambre est reliée à la canalisation 102. Le tiroir 310 comporte une première surface active 314 disposée dans la chambre 308, et donc soumise dans le sens de l'ouverture à MAX(P) et une deuxième surface active 315 disposée dans la chambre 309, ce qui fait que la pression produite agit sur la surface 315 dans le sens de la fermeture.MAX (P) prevails in the chamber 308 because this chamber is connected to the pipe 102. The drawer 310 has a first active surface 314 disposed in the chamber 308, and therefore subjected in the direction of opening to MAX (P ) and a second active surface 315 arranged in the chamber 309, so that the pressure produced acts on the surface 315 in the direction of closing.

On démontre, au cas où la valeur efficace des surfaces 314 et 315 est similaire, et si l'on note S cette valeur, Pp la pression produite et F la force exercée par le ressort, que l'on obtient :

Figure imgb0006
We prove, if the effective value of surfaces 314 and 315 is similar, and if we write S this value, Pp the pressure produced and F the force exerted by the spring, that we obtain:
Figure imgb0006

La pression produite est donc indépendante de la pression fournie par la génération de débit, ce qui permet d'éviter les difficultés que l'on pourrait rencontrer dans le mode de réalisation des figures 1 et 2 dûes au fait qu'on pourrait avoir dans certains distributeurs proportionnels des pressions différentes en amont de l'étranglement procuré par le tiroir compensateur, notamment dans le cas où ces distributeurs sont situés à une distance différente de la génération de débit, et qu'il y a donc des pertes de charge différentes entre la pression de refoulement de celle-ci et la pression régnant dans la chambre référencée 15.The pressure produced is therefore independent of the pressure supplied by the generation of flow, which makes it possible to avoid the difficulties which one could encounter in the embodiment of FIGS. 1 and 2 due to the fact that one could have in certain proportional distributors of the different pressures upstream of the throttle provided by the compensating slide, in particular in the case where these distributors are located at a different distance from the flow generation, and therefore there are different pressure losses between the discharge pressure thereof and the pressure prevailing in the chamber referenced 15.

Dans le cas où les distributeurs proportionnels de l'ensemble de commande sont répartis en plusieurs groupes d'un distributeurou de plusieurs distributeurs voisins, les groupes étant distants les uns des autres, par exemple dans le cas d'un engin de travaux publics, répartis en un premier groupe de deux distributeurs qui commande les moteurs droit et gauche d'avancement du véhicule, un deuxième groupe d'un seul distributeur qui commande la rotation d'une tourelle, et un troisième groupe de plusieurs distributeurs qui commande les différents bras de l'engin, il est préférable de prévoir une valve auxiliaire pour chacun des groupes, non seulement pour éviter les problèmes de perte de charge, mais aussi pour éviter d'avoir à prévoir une canalisation entre une valve auxiliaire centralisée et les différents groupes.In the event that the proportional distributors of the control unit are divided into several groups of a distributor or of several neighboring distributors, the groups being distant from each other, for example in the case of a public works machine, divided into a first group of two distributors which controls the right and left engines for advancing the vehicle, a second group of a single distributor which controls the rotation of a turret, and a third group of several distributors which controls the different arms of the machine, it is preferable to provide an auxiliary valve for each group, not only to avoid pressure drop problems, but also to avoid having to provide a pipe between a centralized auxiliary valve and the different groups.

On obtient un maintien des rapports de vitesse entre récepteurs semblable à celui de l'ensemble montré sur les figures 1 et 2, parce qu'en cas d'excès de la demande en débit, la chambre 307 n'est pas alimentée à une pression suffisante pour que F/S soit rajouté à MAX(P), c'est seulement une valeur inférieure qui est rajoutée, d'autant plus petite que l'excès de demande en débit est grand.Maintaining the speed ratios between receivers similar to that of the assembly shown in FIGS. 1 and 2 is obtained, because in the event of excess demand for flow rate, the chamber 307 is not supplied with a pressure sufficient for F / S to be added to MAX (P), only a lower value is added, the smaller the greater the excess demand for flow.

On notera que les diverses remarques formulées à propos de la forme de réalisation des figures 1 et 2, et notamment celle relative aux variantes possibles, s'appliquent également au mode de réalisation des figures 3 et 4.It will be noted that the various remarks made with regard to the embodiment of FIGS. 1 and 2, and in particular that relating to the possible variants, also apply to the embodiment of FIGS. 3 and 4.

Dans une variante non illustrée de cette dernière forme de réalisation, la valve auxiliaire produit une pression normalement égale à la pression de load-sensing augmentée d'une constante, la liaison de la chambre 308 avec la canalisation 102 étant remplacée par une liaison avec la canalisation 74. On peut dans ce cas supprimer la détection du maximum des pressions en amont de l'étranglement du tiroir commandé, et faire régner la pression de load-sensing dans la chambre 86.11 est également possible, en fonction des circonstances, de choisir une autre pression de régulation que MAX(P) ou la pression de load-sensing. Dans ces variantes, on conserve les avantages de l'utilisation d'une valve auxiliaire.In a variant not illustrated of this latter embodiment, the auxiliary valve produces a pressure normally equal to the load-sensing pressure increased by a constant, the connection of the chamber 308 with the pipe 102 being replaced by a connection with the line 74. In this case, it is possible to suppress the detection of the maximum of the pressures upstream of the throttle of the controlled slide, and to make the load-sensing pressure prevail in the chamber 86.11 is also possible, depending on the circumstances, to choose other control pressure than MAX (P) or load-sensing pressure. In these variants, the advantages of using an auxiliary valve are retained.

Plus généralement, de nombreuses variantes peuvent être apportées aux exemples décrits. A cet égard, on rappelle que l'invention ne se limite pas à ces derniers.More generally, many variations can be made to the examples described. In this regard, it is recalled that the invention is not limited to the latter.

Claims (14)

1. Ensemble de commande d'une pluralité de récepteurs hydrauliques (12, 12'), à travers lequel les récepteurs sont alimentés par une même génération de débit (71) en y étant chacun reliés par l'intermédiaire d'un distributeur proportionnel comportant : - un tiroir commandé (3) dont la position détermine la section d'un premier étranglement ; - un tiroir compensateur pour réguler la différence de pression entre l'amont et l'aval dudit premier étranglement en produisant à l'amont de celui-ci un deuxième étranglement de section appropriée ; et - des moyens d'actionnement du tiroir compensateur, pour lui faire prendre automatiquement une position où il produit ledit deuxième étranglement de section appropriée, en réponse à plusieurs pressions agissant respectivement dans le sens de l'ouverture et dans le sens de la fermeture ; ensemble caractérisé en ce qu'il comporte des moyens (95, 95', 102, 104) pour détecter le maximum des pressions régnant en amont du premier étranglement dans les distributeurs proportionnels respectifs (70, 70' ; 170, 170'), et en ce que dans chacun de ceux-ci lesdits moyens d'actionnement du tiroir compensateur (16, 116) lui font répondre au maximum des pressions en amont ainsi détecté. 1. Control assembly for a plurality of hydraulic receivers (12, 12 '), through which the receivers are supplied by the same generation of flow (71), each being connected thereto by means of a proportional distributor comprising : - a controlled drawer (3) whose position determines the section of a first constriction; - A compensating slide to regulate the pressure difference between the upstream and downstream of said first throttle by producing upstream thereof a second throttle of appropriate section; and - Actuating means of the compensating drawer, to make it automatically take a position where it produces said second throttle of appropriate section, in response to several pressures acting respectively in the direction of opening and in the direction of closing; assembly characterized in that it comprises means (95, 95 ', 102, 104) for detecting the maximum of the pressures prevailing upstream of the first throttle in the respective proportional distributors (70, 70'; 170, 170 '), and in that in each of these said means for actuating the compensating slide (16, 116) make it respond to the maximum of the upstream pressures thus detected. 2. Ensemble selon la revendication 1, caractérisé en ce que dans chaque distributeur proportionnel (70, 70') lesdits moyens d'actionnement du tiroir compensateur (16) sont prévus pour qu'il soit sollicité : - dans le sens de l'ouverture par la pression en aval du premier étranglement et par la pression en amont du deuxième étranglement ; et - dans le sens de la fermeture par la pression en amont du premier étranglement, par ledit maximum des pressions en amont des premiers étranglements respectifs, et par une force sensiblement constante ; ledit ensemble étant ainsi adapté à être utilisé avec une génération de débit (71) produisant une pression de service normalement égale à une pression de régulation qui lui est appliquée, dite load sensing, augmentée d'une constante. 2. Assembly according to claim 1, characterized in that in each proportional distributor (70, 70 ') said means for actuating the compensating drawer (16) are provided so that it is acted upon: - in the direction of opening by the pressure downstream of the first throttle and by the pressure upstream of the second throttle; and - in the direction of closure by the pressure upstream of the first constriction, by said maximum of the pressures upstream of the respective first constrictions, and by a substantially constant force; said assembly thus being adapted to be used with a generation of flow (71) producing a working pressure normally equal to a regulating pressure which is applied thereto, called load sensing, increased by a constant. 3. Ensemble selon la revendication 2, caractérisé en ce que dans chaque distributeur proportionnel, lesdits moyens d'actionnement du tiroir compensateur comportent : sur celui-ci, une première surface active (82) soumise à la pression en aval du premier étranglement, une deuxième surface active (83) soumise à la pression en amont du deuxième étranglement, une troisième surface active (84) soumise à la pression en amont du premier étranglement, et une quatrième surface active (85) soumise audit maximum des pressions en amont des premiers étranglements respectifs, lesdites première et deuxième surfaces (82, 83) étant opposées auxdites troisième et quatrième surfaces (84, 85) ; ainsi qu'un ressort (87) sollicitant le tiroir compensateur (16) dans le sens de la fermeture.3. An assembly according to claim 2, characterized in that in each proportional distributor, said means for actuating the compensating slide comprise: on the latter, a first active surface (82) subjected to the pressure downstream of the first throttle, a second active surface (83) subjected to pressure upstream of the second throttle, a third active surface (84) subjected to pressure upstream of the first throttle, and a fourth active surface (85) subjected to said maximum of pressures upstream of the first respective bottlenecks, said first and second surfaces (82, 83) being opposite said third and fourth surfaces (84, 85); as well as a spring (87) urging the compensating slide (16) in the closing direction. 4. Ensemble selon la revendication 1, caractérisé en ce qu'il comporte en outre au moins une valve auxiliaire (303) alimentée par la génération de débit (71) et produisant une pression normalement égale audit maximum des pressions en amont des premiers étranglements respectifs augmenté d'une constante, et en ce que dans chaque distributeur proportionnel (170, 170') lesdits moyens d'actionnement du tiroir compensateur sont prévus pour qu'il soit sollicité : - dans le sens de l'ouverture par la pression en aval du premier étranglement et par la pression produite par une dite valve auxiliaire (303) ; et - dans le sens de la fermeture par la pression en amont du premier étranglement, par ledit maximum des pressions en amont des premiers étranglements respectifs, et par une force sensiblement constante. 4. The assembly of claim 1, characterized in that it further comprises at least one auxiliary valve (303) supplied by the generation of flow (71) and producing a pressure normally equal to said maximum pressures upstream of the first respective throttles increased by a constant, and in that in each proportional distributor (170, 170 ') said means for actuating the compensating drawer are provided so that it is requested: - in the direction of opening by the pressure downstream of the first throttle and by the pressure produced by a said auxiliary valve (303); and - In the direction of closing by the pressure upstream of the first constriction, by said maximum of the pressures upstream of the respective first constrictions, and by a substantially constant force. 5. Ensemble selon la revendication 4, caractérisé en ce que dans chaque distributeur proportionnel, lesdits moyens d'actionnement du tiroir compensateur comportent sur celui-ci une première surface active (301) soumise à la pression en aval du premier étranglement, une deuxième surface active (302) soumise à la pression produite par la valve auxiliaire, une troisième surface active (84) soumise à la pression en amont du premier étranglement, et une quatrième surface active (85) soumise audit maximum des pressions en amont des premiers étranglements respectifs, lesdites première et deuxième surfaces (301, 302) étant opposées auxdites troisième et quatrième surfaces (84, 85) ; ainsi qu'un ressort (87) sollicitant le tiroir compensateur (116) dans le sens de la fermeture.5. An assembly according to claim 4, characterized in that in each proportional distributor, said actuating means of the compensating slide comprise thereon a first active surface (301) subjected to the pressure downstream of the first throttle, a second surface active (302) subjected to the pressure produced by the auxiliary valve, a third active surface (84) subjected to the pressure upstream of the first constriction, and a fourth active surface (85) subjected to said maximum of the pressures upstream of the respective first constrictions , said first and second surfaces (301, 302) being opposite said third and fourth surfaces (84, 85); as well as a spring (87) urging the compensating slide (116) in the closing direction. 6. Ensemble selon l'une quelconque des revendications 3 ou 5, caractérisé en ce que lesdites première et troisième surfaces actives (82, 84 ; 301, 84) du tiroir compensateur (16, 116) ont un dimensionnement similaire, et en ce que lesdites deuxième et quatrième surfaces (83, 85 ; 302, 85) du tiroir compensateur ont un dimensionnement similaire.6. An assembly according to any one of claims 3 or 5, characterized in that said first and third active surfaces (82, 84; 301, 84) of the compensating slide (16, 116) have a similar dimensioning, and in that said second and fourth surfaces (83, 85; 302, 85) of the compensating drawer have a similar dimensioning. 7. Ensemble selon l'une quelconque des revendications 4 à 6, caractérisé en ce que ladite valve auxiliaire (303) comporte : - une chambre d'alimentation (307) reliée à la génération de débit (71) ; - une chambre de régulation (308) dans laquelle règne ledit maximum des pressions en amont des premiers étranglements respectifs ; - une chambre de sortie (309) où règne ladite pression produite ; - un tiroir (310) dont la position détermine la section d'un étranglement entre la chambre d'alimentation (307) et la chambre de sortie (309), comportant une première surface active disposée dans la chambre de régulation (308) de sorte que ledit maximum des pressions en amont des premiers étranglements respectifs agit dans le sens de l'ouverture, et une deuxième surface active (315) disposée dans la chambre de sortie (309) de sorte que la pression produite agit dans le sens de la fermeture ; et - un ressort (312), qui agit sur le tiroir (310) dans le sens de l'ouverture. 7. Assembly according to any one of claims 4 to 6, characterized in that said auxiliary valve (303) comprises: - a supply chamber (307) connected to the flow generation (71); - A regulation chamber (308) in which said maximum pressures prevails upstream of the first respective throttles; - an outlet chamber (309) where said pressure produced prevails; - a drawer (310), the position of which determines the cross section of a throttle between the supply chamber (307) and the outlet chamber (309), comprising a first active surface disposed in the regulation chamber (308) so that said maximum of the pressures upstream of the respective first constrictions acts in the direction of opening, and a second active surface (315) disposed in the outlet chamber (309) so that the pressure produced acts in the direction of closing ; and - A spring (312), which acts on the slide (310) in the direction of opening. 8. Ensemble selon l'une quelconque des revendications 4 à 7, caractérisé, les distributeurs proportionnels étant répartis en plusieurs groupes d'un distributeur ou de plusieurs distributeurs voisins, les groupes étant distants les uns des autres, en ce qu'il comporte pour chaque groupe une dite valve auxiliaire voisine du groupe.8. An assembly according to any one of claims 4 to 7, characterized, the proportional distributors being distributed in several groups of a distributor or of several neighboring distributors, the groups being distant from each other, in that it comprises for each group a so-called auxiliary valve adjacent to the group. 9. Ensemble selon l'une quelconque des revendications 2 à 8, caractérisé en ce que dans chaque distributeur proportionnel (70, 70' ; 170, 170') il y a absence de clapet de non-retour entre lesdits deuxième étranglement et premier étranglement.9. An assembly according to any one of claims 2 to 8, characterized in that in each proportional distributor (70, 70 '; 170, 170') there is no check valve between said second constriction and first constriction . 10. Ensemble selon l'une quelconque des revendications 1 à 9, caractérisé en ce que lesdits moyens pour détecter le maximum des pressions en amont des premiers étranglements respectifs comportent une canalisation commune (102) fermée à une première extrémité et débouchant dans le réservoir à travers une restriction (104) à une deuxième extrémité ; et pour chaque distributeur proportionnel un clapet de non-retour (95, 95') disposé passant entre l'amont du premier étranglement et la conduite commune.10. An assembly according to any one of claims 1 to 9, characterized in that said means for detecting the maximum of the pressures upstream of the first respective throttles comprise a common pipe (102) closed at a first end and opening into the reservoir at through a restriction (104) at a second end; and for each proportional distributor a non-return valve (95, 95 ') arranged passing between the upstream of the first throttle and the common pipe. 11. Ensemble selon l'une quelconque des revendications 1 à 10, caractérisé en ce qu'il comporte des moyens (73, 74, 99, 99') de détection de charge dits "load-sensing" qui ramènent vers la génération de débit (71) la pression du récepteur le plus chargé.11. An assembly according to any one of claims 1 to 10, characterized in that it comprises means (73, 74, 99, 99 ') of load detection called "load-sensing" which lead to the generation of flow (71) the pressure of the most loaded receiver. 12. Ensemble selon la revendication 11, caractérisé en ce que les moyens de détection de charge comportent pour chaque distributeur proportionnel une canalisation qui relie l'aval du premier étranglement un sélecteurde circuit (99, 99'), et en ce que dans le cas où il y en a plusieurs les sélecteurs de circuit sont disposés en cascade.12. The assembly of claim 11, characterized in that the load detection means comprise for each proportional distributor a pipe which connects the downstream of the first throttle a circuit selector (99, 99 '), and in that in the case where there are several the circuit selectors are arranged in cascade. 13. Ensemble selon l'une quelconque des revendications 1 à 12, caractérisé en ce que chaque distributeur proportionnel comporte un corps statorique (1) comportant des canalisations (73, 74, 102) qui le traverse entièrement, de sorte qu'on a la possibilité d'effectuer des raccordements entre distributeurs, en accolant simplement ces derniers bout à bout.13. An assembly according to any one of claims 1 to 12, characterized in that each proportional distributor comprises a stator body (1) comprising pipes (73, 74, 102) which passes entirely through it, so that there is the possibility of making connections between distributors, by simply joining these end to end. 14. Ensemble selon la revendication 10 combinée à la revendication 3 ou à la revendication 5, caractérisé en ce que chaque distributeur proportionnel comporte un corps statorique (1) comportant des canalisations (73, 74, 102) qui le traverse entièrement, de sorte qu'on a la possibilité d'effectuer des raccordements entre distributeurs, en accolant simplement ces derniers bout à bout ; et en ce que ledit clapet de non-retour disposé passant entre l'amont du premier étranglement et la conduite commune, est ménagé dans le tiroir compensateur (16), entre lesdites troisième surface (84) et quatrième surface (85).14. The assembly of claim 10 combined with claim 3 or claim 5, characterized in that each proportional distributor comprises a stator body (1) having pipes (73, 74, 102) which passes entirely through it, so that 'we have the possibility of making connections between distributors, by simply joining the latter end to end; and in that said non-return valve disposed passing between the upstream of the first throttle and the common pipe, is formed in the compensating slide (16), between said third surface (84) and fourth surface (85).
EP19930401787 1992-08-04 1993-07-08 Control system for a plurality of hydraulic actuators Expired - Lifetime EP0582498B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9209659 1992-08-04
FR9209659A FR2694606B1 (en) 1992-08-04 1992-08-04 Control assembly for a plurality of hydraulic receivers.

Publications (2)

Publication Number Publication Date
EP0582498A1 true EP0582498A1 (en) 1994-02-09
EP0582498B1 EP0582498B1 (en) 1996-05-01

Family

ID=9432601

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19930401787 Expired - Lifetime EP0582498B1 (en) 1992-08-04 1993-07-08 Control system for a plurality of hydraulic actuators

Country Status (5)

Country Link
US (1) US5415199A (en)
EP (1) EP0582498B1 (en)
JP (1) JPH06159311A (en)
DE (1) DE69302443T2 (en)
FR (1) FR2694606B1 (en)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4341244C2 (en) * 1993-12-03 1997-08-14 Orenstein & Koppel Ag Control for dividing the flow rate made available by at least one pump in hydraulic systems among several consumers
US5579642A (en) * 1995-05-26 1996-12-03 Husco International, Inc. Pressure compensating hydraulic control system
US5664417A (en) * 1996-03-20 1997-09-09 Husco International, Inc. Control valve for prime mover speed control in hydraulic systems
US5791142A (en) * 1997-03-27 1998-08-11 Husco International, Inc. Hydraulic control valve system with split pressure compensator
US7182097B2 (en) * 2004-08-17 2007-02-27 Walvoil S.P.A. Anti-saturation directional control valve composed of two or more sections with pressure selector compensators
US7854115B2 (en) * 2008-04-25 2010-12-21 Husco International, Inc. Post-pressure compensated hydraulic control valve with load sense pressure limiting
JP6314903B2 (en) * 2015-05-08 2018-04-25 Smc株式会社 Flow path unit and switching valve
US11598353B1 (en) * 2022-02-01 2023-03-07 Sun Hydraulics, Llc Pressure compensation valve with load-sense fluid signal generation and a reverse free flow configuration integrated therewith

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2350380A1 (en) * 1973-10-08 1975-04-17 Hydraulic Industries Control plunger for hydraulic motors - has piston with two operating positions with pressure compensation and reducing valves
FR2339757A1 (en) * 1976-02-02 1977-08-26 Caterpillar Tractor Co IMPROVEMENTS IN HYDRAULIC SYSTEMS WITH SEVERAL WORKING ORGANS OR RECEIVERS IN PARALLEL
FR2548290A1 (en) * 1983-06-14 1985-01-04 Linde Ag HYDRAULIC INSTALLATION COMPRISING A PUMP AND AT LEAST TWO HYDRAULIC POWER UTILIZATION EQUIPMENT POWERED BY THIS PUMP
FR2562632A1 (en) * 1984-04-18 1985-10-11 Bennes Marrel PROPORTIONAL TYPE HYDRAULIC DISTRIBUTOR WITH INFORMATION RECEIVING THE HIGHEST PRESSURES IN USE CIRCUITS
FR2587419A1 (en) * 1985-09-13 1987-03-20 Rexroth Mannesmann Gmbh CONTROL DEVICE FOR AT LEAST TWO HYDRAULIC FLUID CONSUMERS SUPPLIED BY AT LEAST ONE PUMP
EP0427865A1 (en) * 1989-05-02 1991-05-22 Hitachi Construction Machinery Co., Ltd. Hydraulic driving device of construction equipment

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE8801058U1 (en) * 1988-01-29 1988-03-10 Danfoss A/S, Nordborg Hydraulic control valve with pressure sensing device
US5152140A (en) * 1989-10-11 1992-10-06 Hitachi Construction Machinery Co., Ltd. Pressure compensating valve spool positioned by difference in pressure receiving areas for load and inlet pressures
KR940008823B1 (en) * 1990-07-05 1994-09-26 히다찌 겐끼 가부시기가이샤 Hydraulic drive system and valve device
FR2672944A1 (en) * 1991-02-15 1992-08-21 Bennes Marrel PROPORTIONAL DISTRIBUTOR AND CONTROL ARRANGEMENT OF A PLURALITY OF HYDRAULIC RECEIVERS COMPRISING FOR EACH RECEIVER SUCH A DISTRIBUTOR.

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2350380A1 (en) * 1973-10-08 1975-04-17 Hydraulic Industries Control plunger for hydraulic motors - has piston with two operating positions with pressure compensation and reducing valves
FR2339757A1 (en) * 1976-02-02 1977-08-26 Caterpillar Tractor Co IMPROVEMENTS IN HYDRAULIC SYSTEMS WITH SEVERAL WORKING ORGANS OR RECEIVERS IN PARALLEL
FR2548290A1 (en) * 1983-06-14 1985-01-04 Linde Ag HYDRAULIC INSTALLATION COMPRISING A PUMP AND AT LEAST TWO HYDRAULIC POWER UTILIZATION EQUIPMENT POWERED BY THIS PUMP
FR2562632A1 (en) * 1984-04-18 1985-10-11 Bennes Marrel PROPORTIONAL TYPE HYDRAULIC DISTRIBUTOR WITH INFORMATION RECEIVING THE HIGHEST PRESSURES IN USE CIRCUITS
FR2587419A1 (en) * 1985-09-13 1987-03-20 Rexroth Mannesmann Gmbh CONTROL DEVICE FOR AT LEAST TWO HYDRAULIC FLUID CONSUMERS SUPPLIED BY AT LEAST ONE PUMP
EP0427865A1 (en) * 1989-05-02 1991-05-22 Hitachi Construction Machinery Co., Ltd. Hydraulic driving device of construction equipment

Also Published As

Publication number Publication date
US5415199A (en) 1995-05-16
DE69302443T2 (en) 1997-01-16
FR2694606B1 (en) 1994-11-04
EP0582498B1 (en) 1996-05-01
JPH06159311A (en) 1994-06-07
FR2694606A1 (en) 1994-02-11
DE69302443D1 (en) 1996-06-05

Similar Documents

Publication Publication Date Title
EP0566449B1 (en) Hydraulic maximum load and pressure compensating valve
EP2376770B1 (en) Hydraulic motor with radial pistons and control by cylinder
FR2548290A1 (en) HYDRAULIC INSTALLATION COMPRISING A PUMP AND AT LEAST TWO HYDRAULIC POWER UTILIZATION EQUIPMENT POWERED BY THIS PUMP
FR2511736A1 (en) ELECTROHYDRAULIC ADJUSTMENT DEVICE FOR A HYDROSTATIC MACHINE
EP0582498B1 (en) Control system for a plurality of hydraulic actuators
FR2609119A1 (en) DEVICE FOR CONTROLLING AT LEAST TWO HYDRAULIC CONSUMERS WITH PUMP SUPPLY
EP0500419B1 (en) Proportional valve and control system with a plurality of actuators having each such a valve
EP0284460B1 (en) Pressurised fluid mechanism, pump or engine, with several displacement volumes
WO2011048327A1 (en) Hydrostatic transmission device enabling improved braking
FR2813377A1 (en) SYSTEM FOR OPTIMIZING THE YIELD OF AN OIL SUPPLY
EP0582497B1 (en) Control system for a plurality of hydraulic actuators
EP1072791B1 (en) Hydraulic radial piston engine with unique decoupling selector
FR2488332A1 (en) HYDRAULIC SYSTEM FOR DYNAMOMETRIC BRAKING AND FOR ENERGY RECOVERY OF HEAT ENGINES DURING TESTS WITH AC PRODUCTION
EP1097321B1 (en) Valve device for hydraulic engine for driving a large flywheel mass
FR2794496A1 (en) CYLINDER SELECTOR FOR A HYDRAULIC MOTOR AVOIDING BRUTAL BRAKING WHEN CHANGING FROM SMALL CYLINDER TO LARGE CYLINDER
FR2553487A1 (en) DIRECT COUPLING CONTROL DEVICE FOR HYDRAULIC GEAR FOR AUTOMATIC AUTOMOTIVE TRANSMISSION
FR2651541A1 (en) CONTROL CIRCUIT FOR A HYDRAULIC CYLINDER WORKING WITH A VARIABLE FLOW PUMP.
FR2736124A1 (en) HYDROSTATIC ASSEMBLY WITH CONTROLLED SKATING
EP0223686B1 (en) Braking circuit for at least one hydraulic motor
EP0015169B1 (en) Auxiliary propulsion circuit comprising at least one hydraulic motor
FR2510699A1 (en) CONTROL AND CONTROL INSTALLATION FOR AN ADJUSTABLE HYDRAULIC ASSEMBLY
EP0192899B1 (en) Stalling control for a hydraulic system
EP1890900B1 (en) Device for selecting a hydraulic circuit overall capacity
EP1387776A1 (en) Vehicle hydrostatic transmission circuit
FR2467284A1 (en) Hydraulic motor control circuit - has distributor valve combined with brake applied when in neutral

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): BE CH DE DK FR GB IT LI NL SE

17P Request for examination filed

Effective date: 19940310

17Q First examination report despatched

Effective date: 19950914

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): BE CH DE DK FR GB IT LI NL SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 19960501

Ref country code: DK

Effective date: 19960501

REF Corresponds to:

Ref document number: 69302443

Country of ref document: DE

Date of ref document: 19960605

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 19960610

ITF It: translation for a ep patent filed

Owner name: JACOBACCI & PERANI S.P.A.

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Effective date: 19960731

Ref country code: CH

Effective date: 19960731

Ref country code: BE

Effective date: 19960731

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19960801

NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
BERE Be: lapsed

Owner name: MARREL

Effective date: 19960731

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19980629

Year of fee payment: 6

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19990708

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19990708

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20020726

Year of fee payment: 10

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20020816

Year of fee payment: 10

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20040203

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20040331

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20050708