EP1178219B1 - A hydraulic device for controlling a piloting pressure - Google Patents

A hydraulic device for controlling a piloting pressure Download PDF

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Publication number
EP1178219B1
EP1178219B1 EP20000830561 EP00830561A EP1178219B1 EP 1178219 B1 EP1178219 B1 EP 1178219B1 EP 20000830561 EP20000830561 EP 20000830561 EP 00830561 A EP00830561 A EP 00830561A EP 1178219 B1 EP1178219 B1 EP 1178219B1
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EP
European Patent Office
Prior art keywords
pressure
piloting
hydraulic
valve
way valve
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.)
Expired - Lifetime
Application number
EP20000830561
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German (de)
French (fr)
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EP1178219A1 (en
Inventor
Andrea Storci
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OIL CONTROL SpA
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OIL CONTROL SpA
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Publication date
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Priority to EP20000830561 priority Critical patent/EP1178219B1/en
Publication of EP1178219A1 publication Critical patent/EP1178219A1/en
Application granted granted Critical
Publication of EP1178219B1 publication Critical patent/EP1178219B1/en
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B21/00Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
    • F15B21/04Special measures taken in connection with the properties of the fluid
    • F15B21/045Compensating for variations in viscosity or temperature
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/003Systems with load-holding valves
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/30Directional control
    • F15B2211/305Directional control characterised by the type of valves
    • F15B2211/30525Directional control valves, e.g. 4/3-directional control valve
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/30Directional control
    • F15B2211/32Directional control characterised by the type of actuation
    • F15B2211/329Directional control characterised by the type of actuation actuated by fluid pressure
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/30Directional control
    • F15B2211/355Pilot pressure control
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/40Flow control
    • F15B2211/405Flow control characterised by the type of flow control means or valve
    • F15B2211/40515Flow control characterised by the type of flow control means or valve with variable throttles or orifices
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/40Flow control
    • F15B2211/405Flow control characterised by the type of flow control means or valve
    • F15B2211/40576Assemblies of multiple valves
    • F15B2211/40584Assemblies of multiple valves the flow control means arranged in parallel with a check valve
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/40Flow control
    • F15B2211/41Flow control characterised by the positions of the valve element
    • F15B2211/413Flow control characterised by the positions of the valve element the positions being continuously variable, e.g. as realised by proportional valves
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/40Flow control
    • F15B2211/415Flow control characterised by the connections of the flow control means in the circuit
    • F15B2211/41527Flow control characterised by the connections of the flow control means in the circuit being connected to an output member and a directional control valve
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/40Flow control
    • F15B2211/42Flow control characterised by the type of actuation
    • F15B2211/428Flow control characterised by the type of actuation actuated by fluid pressure
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/40Flow control
    • F15B2211/46Control of flow in the return line, i.e. meter-out control
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/40Flow control
    • F15B2211/47Flow control in one direction only
    • F15B2211/473Flow control in one direction only without restriction in the reverse direction
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/50Pressure control
    • F15B2211/505Pressure control characterised by the type of pressure control means
    • F15B2211/50509Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
    • F15B2211/50545Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using braking valves to maintain a back pressure
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/60Circuit components or control therefor
    • F15B2211/635Circuits providing pilot pressure to pilot pressure-controlled fluid circuit elements
    • F15B2211/6355Circuits providing pilot pressure to pilot pressure-controlled fluid circuit elements having valve means
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/60Circuit components or control therefor
    • F15B2211/67Methods for controlling pilot pressure

Description

  • Specifically, though not exclusively, the invention is usefully applied in an actuator hydraulic transmission circuit, for controlling the piloting pressure of an overcentre valve in turn predisposed for controlling a flow rate in a backline of the circuit during a discharge phase.
  • The prior art includes a hydraulic circuit activator in a hydraulic actuator, for example a winch arm cylinder, in which a first circuit branch connects the hydraulic distributor with the actuator chamber associated to load lifting and a second branch connects the distributor with the lowering chamber. The circuit has an overcentre valve predisposed for controlling the flow rate in the first branch during the load descent phase; a pilot line takes a piloting pressure from the second branch which is used to open the overcentre valve during the load descent phase.
  • This type of circuit is prone to instability and oscillation in the overcentre valve on activation of the cylinder or on reversing its direction. In particular, when the load is lowered, there can be a frequent succession of stops and starts in the actuator before it finally stabilises, causing the load to oscillate dangerously.
  • To solve the problem an adjustable choke on the pilot conduit has been used, which determines a loss of localised load by effect of which the pilot pressure PPIL which opens the overcentre valve becomes gradual and controlled with respect to the increase in pressure PB in the second branch (i.e. the branch which during the load lowering phase is the delivery branch). In the diagram of figure 1 the curve S represents the progress of piloting pressure PPIL in relation to the pressure PB in the second branch.
  • A drawback in the above-described prior art solution is the delay in cylinder activation after the operator has selected it. This is especially evident when the liquid operating in the hydraulic circuit is very viscous (for example when cold). This delay is due to the fact that the piloting pressure Ppil reaches value Pv, the value at which the overcentre valve opens (which value is predetermined by the valve spring calibration) when cylinder delivery pressure PB has already reached a relatively high PS value (see figure 1). This means that the cylinder actuation during the lowering phase starts when the pressure PB reaches value PS. The time necessary for pressure PB to reach value PS (to which value Pv of the piloting pressure Ppil corresponds) can be relatively high, resulting in the above-mentioned delay.
  • A hydraulic device according to preamble of claim 1 is known from EP-A-499 694.
  • The main aim of the present invention is to provide a device for controlling a hydraulic piloting pressure which can overcome the above-described drawback in the prior art, i.e. reduce the delay in response to the hydraulically-piloted organ.
  • An advantage of the invention is that it provides a device for controlling piloting of a hydraulically piloted organ, affording immediate and progressive activation of the organ itself. The activation is immediate inasmuch as the activation of the hydraulically-piloted organ follows the operator's command with a very rapid response time, reducing the delay to a minimum, and is also progressive inasmuch as it proceeds gradually and controlledly subsequent to activation.
  • A further advantage of the present invention is to make available a control device which is particularly useful in a hydraulic activation circuit of a hydraulic actuator for piloting an overcentre valve, being able considerably to reduce the delay in overcentre valve opening and thus prevent occurrence of instability and oscillation phenomena in the valve itself.
  • These aims and advantages and more besides are all attained by the present invention according to the appended claims.
  • Further characteristics and advantages of the present invention will better emerge from the detailed description that follows of some preferred but non-exclusive embodiments of the invention, illustrated purely by way of a nonlimiting example in the accompanying figures of the drawings, in which:
  • figure 1 is a pilot Ppil pressure diagram following pressure PB in the delivery conduit during the load lowering phase, respectively for a known valve (S curve) and for a valve made according to the invention (T curve);
  • figure 2 shows a section of a first embodiment of a device made according to the invention;
  • figure 3 is a symbolic representation of the device of figure 2;
  • figure 4 is a diagram of a control system of a hydraulic actuator, comprising the device of figures 2 and 3;
  • figure 5 is a diagram of a control system of a hydraulic actuator, comprising a second embodiment of the device of the invention;
  • figure 6 is the device of the invention applied on a liquid-delivery hydraulic control organ.
  • With reference to figures 2 and 3, 1 denotes in its entirety a hydraulic device for controlling a piloting pressure.
  • The device 1 comprises a two-way valve 2 destined to operate on a hydraulic pilot conduit operating on at least one hydraulically piloted organ.
  • The two-way valve 2 has a first line 3 connected to a piloting pressure and a second line 4 connected to the organ which is to be hydraulically piloted. The piloting pressure, supplied by the first line 3 of the two-way valve 2, is supplied to the organ to be piloted through the second line 4.
  • The two-way valve 2 can assume an open position in which it enables communication between the first line 3 and the second line 4, and a closed position in which it prevents passage of the operating liquid in the pilot conduit from the first line 3 to the second line 4.
  • The valve 2 is normally open and is predisposed to close by effect of a predetermined pressure on the first line 3. The two-way valve 2 is provided with an obturator, which is a body of revolution, in the illustrated embodiment a sphere, axially mobile inside an internal conduit of the two-way valve 2; the conduit is passed through by the operative liquid of the hydraulic pilot conduit.
  • A first elastic element 6, which is adjustable, can open the obturator 5 by means of an interpositioning of a piston arm 7. The obturator 5 is located between a first end of the piston arm 7 and a second elastic element 8 i.e. a helix spring, opposing the first elastic element 6 but having a considerably lower load than the first elastic element 6. A second end of the piston arm 7, opposite to the first end, is in communication with the outside environment, normally at a pressure (for example atmospheric pressure) which is lower than the pressure internally of the valve 2. The obturator 5 closes automatically when the directional thrust of the piston arm 7 due to the internal pressure of the valve 2 overcomes the thrust due to the load of first elastic element 6 acting in the opposite direction.
  • Between the obturator 5 and the walls of the conduit housing the obturator there is a relatively narrow annular passage (in the shape of a circular crown). The obturator 5 is drawn by the liquid towards the closed position by effect of the thrust following the fall in pressure the liquid passing through the annular passage undergoes. Consequently, the closure of the obturator 5 is abrupt in a case where there is a relatively high liquid flow rate flowing to the first line.
  • Figure 4 shows a control system for a hydraulic actuator 9 which applies the device 1 of figures 2 and 3. The hydraulic actuator 9 has a first chamber 10 and a second chamber 11 associated respectively to the lifting and lowering of a load.
  • The control system comprises: a hydraulic distributor 13; a hydraulic circuit having a first branch 14 which connects the distributor 13 with the first chamber 10 and a second branch 15 which connects the distributor 13 with the second chamber 11; an overcentre valve 16 for controlling the flow rate into the first branch 14 during the load 12 lowering phase; a piloting conduit 17 which takes from the second branch 15 a piloting pressure which opens the flow-rate control, or overcentre valve 16.
  • The flow-rate control valve is an overcentre valve 16 of known type, having a first connection which is connected to the first chamber 10 and a second connection which is connected to the distributor 13. The overcentre valve has an axially-mobile first obturator which operates between the first and the second connection, which is closed by a spring and opened by a piloting pressure provided through a piloting connection. The overcentre valve comprises a single-acting valve predisposed in parallel with the first obturator to allow flow from the second to the first connection. The first obturator is destined to open by effect of the pressure at the piloting connection.
  • The hydraulic control device 1 of figures 2 and 3 is predisposed on the piloting conduit 17; the first line 3 is connected to the second branch 15, i.e. the delivery branch during the discharge phase, and the second line 4 is connected to the overcentre valve 16 for controlling the flow rate.
  • During operation, on initiating the load lowering phase, that is, when the distributor begins sending the pressurised liquid to the second chamber 11 of the actuator through the second branch 15, the pressure PB in the second branch 15 increases, and so does the pressure in the piloting conduit 17. Since the two-way valve 2 is open, the piloting pressure PPIL acting to open the overcentre valve 16 is the same as pressure PB in the second branch 15. The piloting pressure PPIL at the pilot connection of the overcentre valve 16 reaches the predetermined value at which the overcentre valve 16 opens in a relatively short time. This piloting pressure PPIL is limited by the two-way valve 2 which closes the piloting conduit 17 when the pressure PB in the first line 3 exceeds the calibration value of the first elastic element 6 or spring.
  • Figure 5 illustrates a control system for a hydraulic actuator which comprises all of the elements of the system shown in figure 4 (the same elements have the same numbers). In this embodiment, however, the control device 18 comprises, apart from the two-way valve 2, also a choke 19 (or any other device which causes a considerable loss of localised load in the circuit), which is located in parallel with the two-way valve 2 on an auxiliary by-pass conduit 20. The choke 19 can be fixed or adjustable.
  • The first elastic element 6 of the two-way valve 2 is calibrated so that the two-way valve 2 closes when the pressure in the first line 3 has a value Px which is slightly lower than that of value Pv of the piloting pressure determining the start of the opening of the overcentre valve 16 for controlling the flow rate (see figure 1).
  • During operation, on starting the load lowering phase the two-way valve 2 is open and the overcentre valve 16 closed. The pilot connection of the overcentre valve 16 is directly connected, through the piloting conduit 17, to the second branch 15 of the circuit.
  • The operator working the control system commands an increase in pressure of delivery PB to the second chamber 11. In figure 1 the curve T indicates the piloting pressure provided to the overcentre valve 16 according to the pressure PB in the second branch 15. When the pressure PB reaches a certain predetermined value Px the two-way valve 2 automatically closes. In this situation the piloting connection of the overcentre valve 16 (still closed at this point) communicates with the second branch 15 through the by-pass conduit 20.
  • On increasing the pressure PB the piloting pressure PPIL also continues to increase, but at a lower gradient than when the two-way valve 2 was open (see curve T of figure 1). This gradient depends on the fall in pressure caused by the stabilising choke 19 located in the by-pass conduit 20. The piloting pressure reaches a predetermined value Pv at which the overcentre valve 16 opens when the pressure PB is at a predetermined value PT.
  • By observing the curve S of figure 1, which indicates the progress of the piloting pressure for a control device of known type, constituted by a choke to stabilise the actuator discharge phase, it can be seen that the piloting pressure reaches value Pv, at which the overcentre valve 16 begins to open when the pressure PB in the delivery branch has reached value PS during the discharge phase.
  • By comparing the two curves, T and S, Pr emerges as considerably lower than PS, so that thanks to the device of the invention the overcentre valve 16 controlling the flow rate opens well before the prior art valves. Thus, thanks to the device of the invention, the start-up of the actuator during the load lowering phase follows the operator's input command very quickly. In other words, the actuator response to the initialising of the descent phase of the load follows the operator's command very promptly.
  • It has been seen that the choke 19, which has the task of stabilising the actuator 9 operation during the load lowering phase, carries out this task effectively even if the passage section of the choke itself is relatively large. In particular, the choke 19 of the device of the invention can be decidedly more "open" with respect to a stabilising choke of known type. This is evidenced in figure 1, from the fact that the gradient of curve S, relative to a choke of known type, is less than the gradient of the second tract (in which PPIL is greater than Px) of the curve T, relative to the choke used in the device of the invention. It has been seen that this confers on the operator a more direct and immediate degree of control of the actuator. The actuator response is even more immediate to any and every variation in position of the command distributor 13, with a consequent enormous facilitation in the guiding of the actuator 9.
  • The control device 18 operatively associated with the system illustrated in figure 5 enables the overcentre valve 16 to be automatically closed when the pressure PB in the second branch 15 falls.
  • The control devices 1 and 18 of the systems illustrated in figures 4 and 5 can be separate from the overcentre valve 16 and arranged on the piloting conduit 17, or can also be incorporated in a single body with the overcentre valve 16.
  • Figure 6 shows a hydraulic distributor 21 with a double pilot, in which each pilot is controlled by a control device 18 as in figure 5. Two piloting conduits 22 and 23 are connected to the distributor 21 and each is also connected to a supply of a piloting pressure. A two-way valve operates on each piloting conduit; the two-way valves are normally open and are closed by effect of the piloting pressure coming from the above-mentioned supply. When a two-way valve 2 is closed, the distributor 21 is connected to the corresponding supply through the choke 19 on the by-pass conduit 20.
  • The control device can be used for piloting any hydraulically piloted organ, with the aim of obtaining a very rapid activation of the piloted organ in response to an external command supplied through the supply of piloting pressure. The device prevents delays in the activation of the hydraulically-piloted organ and at the same time prevents instability phenomena in the operation of the piloted organ after activation.

Claims (5)

  1. A hydraulic device for controlling a piloting pressure (1, 18) comprising: a pilot pressure delivery; a two-way valve (2), operating in a hydraulic piloting conduit (17, 22, 23) connected to at least one valve (16, 21) to be hydraulically piloted, which two-way valve (2) is provided with at least a first line (3) which receives the piloting pressure (1, 18) from said pilot pressure delivery and a second line (4) through which the piloting pressure is supplied to the at least one valve (16, 21); the two-way valve (2) being able to assume an open position in which it enables a communication between the first line (3) and the second line (4), and a closed position, in which it prevents flow in the hydraulic piloting conduit (17, 22, 23) from the first line (3) to the second line (4); a choke (19) arranged in parallel with the two-way valve (2) on an auxiliary by-pass conduit (20);
    characterised in that the two-way valve (2) is normally open at the pilot delivery pressure and is predisposed to stay open until the pressure in the first line (3) exceeds a calibration value of the first elastic element (6) or spring, said pressure exceeding the calibration value of the first elastic element (6) or spring being slightly lower than the value of the piloting pressure which determines the start of the opening of said at least one valve (16, 21), so that the two-way valve (2) remains open along a major portion of the curve (Fig.1) representing pilot pressure increase vs. delivery pressure increase, and closes only at a piloting pressure slightly lower than the opening pressure of said at least one valve (16, 21).
  2. The device of claim 1, characterised in that the choke (19) can be calibrated.
  3. The device of any one of the preceding claims, characterised in that the two-way valve (2) comprises at least one obturator (5) thrust into an open position by at least one elastic element (6) through an interpositioning of a piston arm (7), through which piston arm (7) a difference in pressure between an inside of the two-way valve (2) and an external environment acts antagonistically against the elastic element (6).
  4. The device of any one of the preceding claims, characterised in that the two-way valve (2) is provided with at least one obturator (5) having a shape of a body of revolution, which at least one obturator (5) is axially mobile inside a conduit crossed by a liquid of the hydraulic piloting conduit (17, 22, 23), the at least one obturator (5) being drawn by the liquid towards the closed position by effect of a thrust due to a fall in pressure in the liquid crossing an annular passage afforded between the obturator (5) and a wall of the hydraulic piloting conduit (17, 22, 23).
  5. A control system of a hydraulic actuator (9), in which:
    the hydraulic actuator (9) has a first chamber (10) and a second chamber (11) respectively associated to a lifting and a lowering of a load (12);
    the control system comprises at least one distributor (13), at least one hydraulic circuit having a first branch (14) which connects the distributor (13) with the first chamber (10) and a second branch (15) which connects the distributor (13) with the second chamber (11); at least one valve (16) for controlling a flow rate in the first branch (14) during a load lowering phase; at least one hydraulic piloting conduit (17) which takes from the second branch (15) a piloting pressure which is used to open the valve (16) controlling the flow rate;
    characterised in that it further comprises a hydraulic device (1, 18), predisposed on the hydraulic piloting conduit (17) for controlling the piloting pressure, made according to any one of the preceding claims.
EP20000830561 2000-08-04 2000-08-04 A hydraulic device for controlling a piloting pressure Expired - Lifetime EP1178219B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP20000830561 EP1178219B1 (en) 2000-08-04 2000-08-04 A hydraulic device for controlling a piloting pressure

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE2000619743 DE60019743T2 (en) 2000-08-04 2000-08-04 Hydraulic device for controlling a pilot pressure
EP20000830561 EP1178219B1 (en) 2000-08-04 2000-08-04 A hydraulic device for controlling a piloting pressure
AT00830561T AT294332T (en) 2000-08-04 2000-08-04 Hydraulic device for controlling a pressure pressure

Publications (2)

Publication Number Publication Date
EP1178219A1 EP1178219A1 (en) 2002-02-06
EP1178219B1 true EP1178219B1 (en) 2005-04-27

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP20000830561 Expired - Lifetime EP1178219B1 (en) 2000-08-04 2000-08-04 A hydraulic device for controlling a piloting pressure

Country Status (3)

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EP (1) EP1178219B1 (en)
AT (1) AT294332T (en)
DE (1) DE60019743T2 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2341253A1 (en) * 2010-01-05 2011-07-06 Nem S.P.A. Device for piloting by means of a substantially incompressible fluid
EP2372167A1 (en) * 2010-03-30 2011-10-05 Bosch Rexroth Oil Control S.p.A. A device for controlling a piloting pressure, in particular of a balance valve.

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102006024183A1 (en) * 2006-05-23 2007-11-29 Robert Bosch Gmbh Pilot operated valve
ITPR20090100A1 (en) 2009-11-30 2011-06-01 Walvoil Spa Pilot pressure signal control device
ITMO20120042A1 (en) 2012-02-22 2013-08-23 Atlantic Fluid Tech S R L LOAD DISPLACEMENT VALVE
IT201700062799A1 (en) * 2017-06-08 2018-12-08 Vbr S R L Control device of a hydraulic cylinder

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4105459C2 (en) * 1991-02-21 1993-03-18 Heilmeier & Weinlein Fabrik Fuer Oel-Hydraulik Gmbh & Co Kg, 8000 Muenchen, De
DE29808295U1 (en) * 1998-05-07 1998-08-13 Heilmeier & Weinlein Seat valve

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2341253A1 (en) * 2010-01-05 2011-07-06 Nem S.P.A. Device for piloting by means of a substantially incompressible fluid
EP2372167A1 (en) * 2010-03-30 2011-10-05 Bosch Rexroth Oil Control S.p.A. A device for controlling a piloting pressure, in particular of a balance valve.

Also Published As

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DE60019743D1 (en) 2005-06-02
EP1178219A1 (en) 2002-02-06
DE60019743T2 (en) 2006-03-02
AT294332T (en) 2005-05-15

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