EP0548513B1 - Flow control device for a working fluid - Google Patents

Flow control device for a working fluid Download PDF

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Publication number
EP0548513B1
EP0548513B1 EP92118860A EP92118860A EP0548513B1 EP 0548513 B1 EP0548513 B1 EP 0548513B1 EP 92118860 A EP92118860 A EP 92118860A EP 92118860 A EP92118860 A EP 92118860A EP 0548513 B1 EP0548513 B1 EP 0548513B1
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EP
European Patent Office
Prior art keywords
valve
pilot valve
control device
bore
valve member
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
EP92118860A
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German (de)
French (fr)
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EP0548513A1 (en
Inventor
Hartmut Dipl.-Ing.(Fh) Sandau
Holger Dipl.-Ing. Lueues
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Robert Bosch GmbH
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Robert Bosch GmbH
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Publication of EP0548513A1 publication Critical patent/EP0548513A1/en
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    • 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
    • F15B13/01—Locking-valves or other detent i.e. load-holding devices
    • F15B13/015—Locking-valves or other detent i.e. load-holding devices using an enclosed pilot flow valve

Definitions

  • the invention relates to a control device according to the type specified in the preamble of claim 1.
  • Such a control device is already known from CH-A-543 028, in which, with the aid of a finely controllable shut-off valve, a so-called lowering valve, it is achieved that, for example, the load acting on a hydraulic working cylinder does not lead the assigned volume flow when lowering.
  • This shut-off valve has a seat valve body, which is pressed against a housing-fixed main valve seat by a relatively strong compression spring arranged in a pressure chamber.
  • the seat valve body accommodates in its interior a spherical, spring-loaded pilot valve member, which can be unlocked by an actuating device, which is designed here as a hydraulically actuated unlocking piston with an associated tappet.
  • the release piston When lowering with this check valve, the release piston rests against the poppet valve body, whereby the spherical pilot valve member is opened by the tappet and works as a simple check valve that controls a constant cross-section between the pressure chamber and the outlet.
  • the seat valve body has an axial notch on the outer circumference, which forms an adjustable throttle cross section between a pressure chamber of the working cylinder and the pressure chamber in the check valve.
  • the level of the hydraulic pressure at the unlocking piston is weighed against the force of the compression spring and the pressure in the pressure chamber and determines the stroke of the Check valve, which thus works with pure pilot control. A sequential control between the main control element and pilot control element is not possible.
  • a control device for the volume flow of a hydraulic working device in which a seat valve body cooperates with a pilot valve member arranged in it in the manner of a sequence control.
  • the pilot valve member which is actuated by a proportional magnet against the force of a spring, controls a connection from a pressure chamber on the seat valve body to the tank with its adjustable throttle point.
  • the seat valve body working as the main stage is formed here in the area of the main valve seat as a flat cone, which merges directly into a fine control cone, which can lead to discontinuities in the valve characteristic.
  • a control device is also known in which, with the aid of a finely controllable shut-off valve - a so-called lowering valve - it is achieved that, for example, the load acting on a consumer does not lead the associated pressure medium flow when lowering.
  • This check valve has a seat valve body in which a pilot valve member is guided. This pilot valve member projects into a closing bore with a control pin.
  • Such a check valve has the disadvantage that pressure medium can only drain when the control pin of the pilot valve member emerges from the drain hole.
  • the actuation path over which an actuating device must move the pilot valve member before the pressure medium can flow out is very long.
  • the control device with the characterizing features of the main claim has the advantage that the actuation paths for the check valve (lowering valve) are very short and the required actuation forces are low, so that the requirements for the use of proportional magnets as an actuating device are met.
  • the pressure medium flow can then be finely controlled. This is achieved by a sequential control of the pilot valve member and seat valve body, which is made possible by the shape of the seat valve body and the design of the pilot valve member. This ensures in particular a continuous, finely controllable outflow of the pressure medium from the pressure chamber of the working cylinder. Furthermore, by using seat valves in the closed state, extremely low leakages are achieved, so that loads are held for very long times.
  • FIG. 1 shows a hydraulic control device with a check valve in longitudinal section in FIG. 1, and a modification of the check valve in longitudinal section in FIG.
  • a pump 10 draws in pressure medium from a container 11, which is fed via a 3/2-way valve 12 and a check valve 13 to a single-acting working cylinder 14 and via a line branch 15 between working cylinder 14 and check valve 13 to a check valve 16 becomes.
  • the working cylinder 14 has a pressure chamber 17 in which a piston 18 with a piston rod 19 is guided.
  • a return line 20 leads from the shutoff valve 16 to the container 11.
  • the check valve 16 has a valve housing 21 which is penetrated in the longitudinal direction by a double-stepped bore, the bore sections of which are continuously designated 22a to 22c. This bore starts from a cylindrical recess 23, which in turn is embedded in an end face 24 of the housing 21.
  • annular grooves 25 to 28 are embedded in the central bore section 22b, the annular groove 25 being arranged in the central region of the bore section 22b.
  • the annular groove 28 is located at the transition to the bore section 22a, which is provided with an internal thread.
  • the annular groove 26 extending between the annular grooves 25 and 27 or 28 is wider and deeper and is connected via a pressure medium channel 29 penetrating the housing 21 to the line branch 15 leading to the working cylinder 14 or to the check valve 13.
  • a pressure medium channel 29 penetrating the housing 21 to the line branch 15 leading to the working cylinder 14 or to the check valve 13.
  • an annular groove 30 which is connected via a channel 31 penetrating the housing 21 to the return line 20 leading to the container 11.
  • valve housing 21 is closed on one side by a plug 33. This is inserted into the bore section 22b and, with a shoulder 34 of smaller diameter, lies against the annular shoulder 35 formed by the transition from the bore section 22b to the bore section 22c. To seal this paragraph 34 is surrounded by a sealing ring 36.
  • intermediate rings 37, 38 On the side of the plug 33 facing away from the bore section 22c there are intermediate rings 37, 38 arranged one behind the other, on which a cylindrical valve insert 39 is supported. This is fixed by a clamping screw 40 with a continuous hexagon socket 40a. This is screwed into the bore section 22a and bears against the lower end face 41 of the valve insert 39.
  • An axially extending bore 42 extends from this end face 41 in the valve insert 39 and opens into an axially aligned bore 43 of larger diameter.
  • This bore 43 starts from the end face 44 of the valve insert 39 resting on the intermediate ring 38.
  • the transition of the bores 42, 43 is designed as a main valve seat 45. In the area of this main valve seat 45, an annular groove 46 is arranged in the bore 43, from which a plurality of radially extending bores 47 extend, which penetrate the valve insert 39 and are connected to the annular groove 26 in the valve housing 21.
  • a seat valve body 51 is inserted into the valve insert 39 from the bore 43. This has a tapered section which interacts as a valve cone 52 with the main valve seat 45.
  • a cylindrical extension 53 extends from the valve cone 52 and protrudes into the annular groove 49 and merges there into an increase 54. This rise 54 widens conically to the diameter of the bore 42. The rise 54 is designed such that its largest diameter lies in the area of the bore 42 when the valve cone 52 abuts the main valve seat 45.
  • the rise 54 is followed by a short, cylindrical section 55 which, when the poppet valve body 51 is in the position described above, projects into the section of the bore 42 facing the end face 41.
  • This cylindrical section 55 merges into a tapered fine control cone 56 which projects through the bore 42 into the bore section 22a.
  • a cylindrical recess 59 is embedded in the end face 58 of the seat valve body 51 facing the intermediate rings 37, 38, from which a smaller longitudinal bore 60 extending in the same axis extends.
  • the base of the longitudinal bore 60 is conical towards the end face 63 and serves as a valve seat 61, which merges into an opposing, conical recess 62 which widens up to the opposite end face 63 of the seat valve body 51.
  • Two annular grooves 64, 65 are embedded in the longitudinal bore 60, of which the upper annular groove 64 extends in the region of the annular groove 47 of the valve insert 39.
  • the lower annular groove 65 lies at the transition the longitudinal bore 60 to the valve seat 61.
  • a further longitudinal bore 66 is arranged in the seat valve body, which extends from the end face 58 and extends eccentrically and axially parallel to the longitudinal bore 60.
  • This further longitudinal bore 66 extends into the area of the annular groove 64 and is connected to it.
  • the eccentrically arranged longitudinal bore 66 and the annular groove 47 in the valve insert 39 are connected to one another by a throttle bore 67 penetrating the seat valve body 51. Via the eccentric longitudinal bore 66 there is then a connection to a pressure chamber 68 which is formed in the bore 43 in the valve insert 39 between the plug 33 and the seat valve body 51.
  • a cylindrical pilot valve member 70 is inserted, which has a conically tapering section which interacts as a pilot valve cone 71 with the valve seat 61.
  • a cylinder section 72 of smaller diameter adjoining the pilot valve cone projects into the bore section 22a as far as the vicinity of the recess 23 and abuts there against the tappet 73 of a proportional magnet 69.
  • This proportional magnet 69 lies against the end face 24 of the valve housing 21 and closes it.
  • the connection is sealed by a sealing ring 74 inserted into the recess 23.
  • the longitudinal bore 60 of the seat valve body 51 is closed on one side by a plug 75. This is inserted into the recess 59 and projects with a shoulder 76 of smaller diameter into the longitudinal bore 60. In an annular groove 77 arranged in the shoulder 76, a sealing ring 78 is inserted for sealing, which bears against the wall of the longitudinal bore 60.
  • the plug 75 is fixed in place with a retaining ring 80 inserted into a corresponding annular groove 79 in the recess 59. This is designed so that between the paragraph 76 and the pilot valve member 70, a pressure chamber 81 is formed in the longitudinal bore 60 when the pilot valve member 70 bears against the valve seat 61 with its pilot valve cone 71.
  • a longitudinal bore 82 is arranged in the pilot valve member 70, which extends into the cylinder section 72.
  • the longitudinal bore 82 is connected to a transverse throttle bore 83 which penetrates the cylinder section 72.
  • An annular groove 84 is formed on the outer circumference of the pilot valve member 70 and is arranged in the region of the annular groove 65 of the seat valve body 51. Fine control notches 85 with a tapering cross-section extend from this annular groove 84 and extend as far as the annular groove 64. These fine control notches 85 are designed so that they just do not reach the annular groove 64 when the pilot valve cone 71 abuts the valve seat 61.
  • An approximately cup-shaped adjusting screw 87 is inserted into the valve housing 21 by screwing it into the bore section 22a, the bottom 88 of the adjusting screw facing the clamping screw 40 without reaching it.
  • a cylindrical extension 89 extends from the bottom 88 and merges into a truncated cone 90. This protrudes into the conical recess 62 of the seat valve body 51.
  • the cylindrical extension 89 and the truncated cone 90 are penetrated in the axial direction by two merging bores 91, 92 for the passage of the cylinder section 72 of the pilot valve member 70.
  • the bore 91 of smaller diameter runs in the truncated cone 90, its diameter is larger than that of the cylinder section 72.
  • the bore 92 of larger diameter is formed in the cylindrical extension 89 and starts from the interior 93 of the adjusting screw, which is designed as a hexagon socket.
  • the truncated cone 90 is designed such that the throttle bore 83 is located within the recess 62 and outside the bore 91 of the truncated cone 90 when both the pilot valve cone 71 abuts the valve seat 61 and the valve cone 52 on the main valve seat 45.
  • a compression spring 94 is supported, which comprises the cylinder section 72 of the pilot valve member 70 and whose opposite end abuts a pressure ring 95.
  • This pressure ring 95 encompasses the cylinder section 72 in the vicinity of the end face facing the plunger 73 and is secured against being pushed off by a ball segment 96 and a locking ring 97 which is inserted into an annular groove 98 in the cylinder section 72.
  • the check valve 13 prevents a pressure medium flow from the working cylinder 14 to the 3/2-way valve 12 Ring groove 46 build-up pressure acts via the throttle bore 67 and the bore 66 also in the pressure chamber 68 and in the annular groove 64 of the seat valve body 51.
  • This annular groove is sealed against the annular groove 65 by the pilot valve member 70.
  • the annular groove 49 in the valve insert 39 is sealed against the annular groove 30 and thus the return line 20 by the cylindrical section 55 of the fine control cone 56 located in the bore 42.
  • the seat valve body 51 is therefore additionally pressed by the action of the pressure in the pressure chamber 68 against the main valve seat 45 of the valve insert 39. This contact pressure is reduced by the force due to the effect of the pressure in the ring grooves 26 and 46 on the ring surface between the outer circumference of the seat valve body 51 and the effective sealing circumference on the main valve seat 45.
  • the pressure in the return line 20 (pressure in the container 11) prevails through the connection via the channel 31 also in the annular groove 30. From there past the truncated cone 90 via the throttle bore 83 there is a connection to the longitudinal bore 82 in the pilot valve member 70 and thus to the pressure chamber 81 There is still a connection to the interior 93 of the adjusting screw 87 via the annular space between the bore 91 and the cylinder section 72.
  • the pilot valve member 70 is moved upward by the plunger 73 via the cylinder section 72.
  • the pilot valve cone 71 stands out from the valve seat 61 and the fine control notches 85 reach the area of the annular groove 64.
  • the pressure medium under pressure in the pressure chamber 68 can then get into the annular groove 65 via the bore 66, the annular groove 64 and the fine control notches 85.
  • the pressure in the pressure chamber 68 drops as a function of the opening cross section (immersion depth of the fine control notches 85 in the region of the annular groove 64).
  • This pressure is established in accordance with the ratio of the throttle cross section at the throttle 67 and the opening cross section of the fine control notches 85. Falls accordingly far pushed up pilot valve member 70, the pressure in the pressure chamber 68 so far that the compressive forces in the annular groove 46 predominate on the annular surface between the outer circumference of the seat valve body 51 and the sealing circumference on the main valve seat 45, the seat valve body 51 is lifted from the main valve seat 45. Pressure medium from the annular groove 46 then flows past the opened main valve seat 45 into the annular groove 49. From there, there is a connection past the fine control cone 56, which is immersed in the annular groove 49, to the hexagon socket 40a. Pressure medium passes from there to the annular groove 30 and thus via the return line 20 to the container 11.
  • the opening movement of the seat valve body 51 reduces the relative displacement between the latter and the pilot valve member 70, so that the opening cross section at the fine control notches 85 becomes smaller. This allows a higher pressure to build up in the pressure chamber 68 via the throttle 67. Thus, the opening movement of the seat valve body 51 is braked until an equilibrium is reached. Pressure medium from the annular groove 46 or the line branch 15 can now flow out evenly, so that the load to be lowered on the working cylinder 14 does not lead ahead, and buzzing noises and jerking of the working cylinder are prevented.
  • the pilot valve member 70 follows this movement due to the action of the compression spring 94.
  • the opening cross section of the fine control notches 85 thus becomes even smaller or zero, so that the pressure in the pressure chamber 68 increases. Due to this increasing pressure in the pressure chamber 68 and the mechanical guidance of the pilot valve member 70 via the pilot valve cone 71 on the valve seat 61, the seat valve body 51 is also moved downward (sequential control).
  • the force to move the pilot valve member 70 is primarily dependent on the biasing force of the compression spring 94. This biasing force can be varied by a corresponding screwing depth of the adjusting screw 88.
  • the pilot valve member 70 is pressed via the tappet 73 of the proportional magnet 69 up to the shoulder 76 of the plug 75, so that the seat valve body 51 is thus moved.
  • the 3/2-way valve 12 is brought into the switching position II, so that pressure medium flows through the pump 10 via the check valve 13 in the through position to the working cylinder 14.
  • the check valve 16 is characterized - as already described - by the low required actuation forces and by short actuation paths.
  • the hydraulic forces on the pilot valve member 70 are almost equalized and dynamic pressures on the pilot valve member 70 in the region of the valve seat 71 or the adjusting screw 87 are avoided by the respective conical design of the poppet valve body and the adjusting screw 87 in the region of the truncated cone 90.
  • both the pilot control volume flow past the valve seat 71 and the main volume flow past the opened fine control cone 56 are diverted to the annular groove 30 without significant backpressures occurring in the area of the cylinder section 72 in the interior 93 of the adjusting screw 87.
  • valve cone 52 and fine control cone 56 Due to the spatial separation of valve cone 52 and fine control cone 56, these can be manufactured without great manufacturing outlay. If the seat valve body 51 is moved upward, the valve cone 52 lifts off the main valve seat 45. However, pressure medium cannot yet flow out of the annular groove 49, since the short cylindrical section 55 on the fine control cone 56 is still arranged within the bore 42 (gap seal). Only when this short cylindrical section 55 emerges from the bore 42 can the pressure medium flow increase as a function of the depth of immersion of the fine control cone 56. Discontinuities in the volume flow curve when the seat valve body is opened are thus avoided since the sealing point of the valve cone 52 on the main valve seat 45 is followed by the gap seal on the fine control cone 55, 56.
  • FIG. 2 shows a modified embodiment of the check valve, in which the design of the pilot valve member 70a and that of the seat valve body 51a are changed.
  • the pilot valve member 70a differs from that previously described by an elongated longitudinal bore 82a. This also penetrates the cylinder section 72a almost completely, ie it extends to the vicinity of its free end face.
  • a transverse throttle bore 100 opens into the longitudinal bore, which connects it to the interior 93 of the adjusting screw 87.
  • the throttle bore 83a is formed in the latter, which also opens into the longitudinal bore 82a.
  • the cylindrical section 55 on the seat valve body 51a merges into a cylindrical fine control section 56a of the same diameter.
  • triangular fine control notches 101 are arranged, which point towards the cylindrical section 55 and taper towards it.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Magnetically Actuated Valves (AREA)
  • Fluid-Driven Valves (AREA)
  • Lift Valve (AREA)

Description

Stand der TechnikState of the art

Die Erfindung geht aus von einer Steuervorrichtung nach der im Oberbegriff des Anspruchs 1 näher angegebenen Gattung.The invention relates to a control device according to the type specified in the preamble of claim 1.

Eine derartige Steuervorrichtung ist bereits aus der CH-A-543 028 bekannt, bei der mit Hilfe eines feinsteuerbaren Sperrventils, eines sog. Senkventils, erreicht wird, daß beispielsweise die an einem hydraulischen Arbeitszylinder wirkende Last beim Senken dem zugeordneten Volumenstrom nicht vorauseilt. Dieses Sperrventil weist einen Sitzventilkörper auf, der von einer in einem Druckraum angeordneten, relativ starken Druckfeder gegen einen gehäusefesten Hauptventilsitz gedrückt wird. Der Sitzventilkörper nimmt in seinem Inneren ein kugeliges, federbelastetes Vorsteuerventilglied auf, das von einer Betätigungseinrichtung entsperrbar ist, die hier als hydraulisch beaufschlagter Entsperrkolben mit zugeordnetem Stößel ausgebildet ist. Beim Senken mit diesem Sperrventil legt sich der Entsperrkolben an den Sitzventilkörper an, wobei das kugelige Vorsteuerventilglied vom Stößel geöffnet wird und als einfaches Rückschlagventil arbeitet, das einen konstanten Querschnitt zwischen Druckraum und Ablauf steuert. Der Sitzventilkörper hat am Außenumfang eine axiale Kerbe, die einen verstellbaren Drosselquerschnitt zwischen einem Druckraum des Arbeitszylinders und dem Druckraum im Sperrventil bildet. Die Höhe des hydraulischen Drucks am Entsperrkolben wird gegen die Kraft der Druckfeder und des Drucks im Druckraum aufgewogen und bestimmt den Hub des Sperrventils, das somit mit einer reinen Vorsteuerung arbeitet. Eine Folgesteuerung zwischen Hauptsteuerglied und Vorsteuerglied ist nicht möglich.Such a control device is already known from CH-A-543 028, in which, with the aid of a finely controllable shut-off valve, a so-called lowering valve, it is achieved that, for example, the load acting on a hydraulic working cylinder does not lead the assigned volume flow when lowering. This shut-off valve has a seat valve body, which is pressed against a housing-fixed main valve seat by a relatively strong compression spring arranged in a pressure chamber. The seat valve body accommodates in its interior a spherical, spring-loaded pilot valve member, which can be unlocked by an actuating device, which is designed here as a hydraulically actuated unlocking piston with an associated tappet. When lowering with this check valve, the release piston rests against the poppet valve body, whereby the spherical pilot valve member is opened by the tappet and works as a simple check valve that controls a constant cross-section between the pressure chamber and the outlet. The seat valve body has an axial notch on the outer circumference, which forms an adjustable throttle cross section between a pressure chamber of the working cylinder and the pressure chamber in the check valve. The level of the hydraulic pressure at the unlocking piston is weighed against the force of the compression spring and the pressure in the pressure chamber and determines the stroke of the Check valve, which thus works with pure pilot control. A sequential control between the main control element and pilot control element is not possible.

Ferner wurde nach der prioritätsälteren nicht vorveröffentlichten Anmeldung WO 92/07194 eine Steuereinrichtung für den Volumenstrom einer hydraulischen Arbeitsvorrichtung vorgeschlagen, bei der ein Sitzventilkörper mit einem in ihm angeordneten Vorsteuerventilglied nach Art einer Folgesteuerung zusammenarbeitet. Das Vorsteuerventilglied, das von einem Proportionalmagneten gegen die Kraft einer Feder betätigt wird, steuert dabei mit seiner verstellbaren Drosselstelle eine Verbindung von einem Druckraum am Sitzventilkörper zum Tank. Der als Hauptstufe arbeitende Sitzventilkörper ist hier im Bereich des Hauptventilsitzes als flacher Konus ausgebildet, der unmittelbar in einen Feinsteuerkegel übergeht, was zu Unstetigkeiten in der Ventilkennlinie führen kann.Furthermore, according to the older, not prepublished application WO 92/07194, a control device for the volume flow of a hydraulic working device was proposed, in which a seat valve body cooperates with a pilot valve member arranged in it in the manner of a sequence control. The pilot valve member, which is actuated by a proportional magnet against the force of a spring, controls a connection from a pressure chamber on the seat valve body to the tank with its adjustable throttle point. The seat valve body working as the main stage is formed here in the area of the main valve seat as a flat cone, which merges directly into a fine control cone, which can lead to discontinuities in the valve characteristic.

Nach der DE-OS 30 42 277 ist ferner eine Steuervorrichtung bekannt, bei der mit Hilfe eines feinsteuerbaren Sperrventils - eines sog. Senkventils - erreicht wird, daß beispielsweise die an einem Verbraucher wirkende Last beim Absenken dem zugeordneten Druckmittelstrom nicht vorauseilt. Dieses Sperrventil weist einen Sitzventilkörper auf, in dem ein Vorsteuerventilglied geführt ist. Dieses Vorsteuerventilglied ragt mit einem Steuerzapfen in eine Abschlußbohrung. Ein derartiges Sperrventil hat den Nachteil, daß Druckmittel erst abfließen kann, wenn der Steuerzapfen des Vorsteuerventilgliedes aus der Abflußbohrung austaucht. Der Betätigungsweg, über den eine Betätigungseinrichtung das Vorsteuerventilglied bewegen muß, bevor das Druckmittel abfließen kann, ist dabei sehr lang.According to DE-OS 30 42 277 a control device is also known in which, with the aid of a finely controllable shut-off valve - a so-called lowering valve - it is achieved that, for example, the load acting on a consumer does not lead the associated pressure medium flow when lowering. This check valve has a seat valve body in which a pilot valve member is guided. This pilot valve member projects into a closing bore with a control pin. Such a check valve has the disadvantage that pressure medium can only drain when the control pin of the pilot valve member emerges from the drain hole. The actuation path over which an actuating device must move the pilot valve member before the pressure medium can flow out is very long.

Aus der US-PS 47 41 364 ist darüberhinaus bekannt, eine Last über ein vorgesteuertes, aufwendig aufgebautes Steuerventil zu heben oder zu senken, wobei dieses Steuerventil einen Hauptsteuerschieber und einen Vorsteuerschieber aufweist. Auf den Vorsteuerschieber wirkt ein Proportionalmagnet als Betätigungseinrichtung. Zur Regelung des Ausgangsdruckes des Steuerventils erfolgt bei diesem ein aufwendiger Kraftvergleich zwischen den Kräften aufgrund der Wirkung einer Druckfeder und aufgrund der Wirkung des Druckes. Eine Folgesteuerung zwischen Hauptsteuerschieber und Vorsteuerschieber ist nicht möglich.From US-PS 47 41 364 is also known to raise or lower a load on a pilot-controlled, complex control valve, this control valve having a main control spool and a pilot spool. Acts on the spool a proportional magnet as an actuator. To regulate the output pressure of the control valve, this involves a complex comparison of forces between the forces due to the action of a compression spring and due to the action of the pressure. A sequential control between the main spool and pilot spool is not possible.

Vorteile der ErfindungAdvantages of the invention

Die erfindungsgemäße Steuervorrichtung mit den kennzeichnenden Merkmalen des Hauptanspruchs hat demgegenüber den Vorteil, daß die Betätigungswege für das Sperrventil (Senkventil) sehr kurz und die benötigten Betätigungskräfte gering sind, so daß die Voraussetzungen für den Einsatz von Proportionalmagneten als Stelleinrichtung erfüllt sind. Damit kann dann der Druckmittelstrom feingesteuert werden. Dies wird durch eine Folgesteuerung von Vorsteuerventilglied und Sitzventilkörper erreicht, die durch die Formgebung des Sitzventilkörpers und die Ausbildung des Vorsteuerventilgliedes ermöglicht wird. Dadurch wird insbesondere ein kontinuierliches, feinsteuerbares Abströmen des Druckmittels aus dem Druckraum des Arbeitszylinders gewährleistet. Desweiteren werden durch den Einsatz von Sitzventilen im geschlossenen Zustand äußerst geringe Leckagen erreicht, so daß Lasten über sehr lange Zeiten gehalten werden. Durch das Zusammenwirken der unveränderlichen Drosselstelle mit der variablen Drosselstelle wird darüberhinaus ein stabiler Verlauf der Ventilkennlinie über einen großen Bereich erzielt. Diese hohe Regelstabilität des Sperrventils führt zu einer schwingungsarmen Arbeitsweise, wodurch auch schnarrende und pfeifende Geräusche vermindert werden. Durch die erfindungsgemäße Steuervorrichtung kann insbesondere der von einem Verbraucher (Arbeitszylinder) zurückfließende Druckmittelstrom gedrosselt werden, so daß kein Vorauseilen der Last oder "Ruckeln" erfolgt.The control device according to the invention with the characterizing features of the main claim has the advantage that the actuation paths for the check valve (lowering valve) are very short and the required actuation forces are low, so that the requirements for the use of proportional magnets as an actuating device are met. The pressure medium flow can then be finely controlled. This is achieved by a sequential control of the pilot valve member and seat valve body, which is made possible by the shape of the seat valve body and the design of the pilot valve member. This ensures in particular a continuous, finely controllable outflow of the pressure medium from the pressure chamber of the working cylinder. Furthermore, by using seat valves in the closed state, extremely low leakages are achieved, so that loads are held for very long times. The interaction of the unchangeable throttle point with the variable throttle point also achieves a stable course of the valve characteristic over a large range. This high control stability of the check valve leads to a low-vibration mode of operation, which also reduces the buzzing and whistling noises. By means of the control device according to the invention, in particular the pressure medium flow flowing back from a consumer (working cylinder) can be throttled, so that the load does not advance or "jerky".

Weitere Vorteile und vorteilhafte Weiterbildungen ergeben sich aus den Unteransprüchen und der Beschreibung.Further advantages and advantageous further developments result from the subclaims and the description.

Zeichnungdrawing

Ein Ausführungsbeispiel der Erfingung ist in der nachfolgenden Beschreibung und Zeichnung näher erläutert. Letztere zeigt in Figur 1 eine hydraulische Steuervorrichtung mit einem Sperrventil im Längsschnitt, in Figur 2 eine Abwandlung des Sperrventils im Längsschnitt.An embodiment of the invention is explained in more detail in the following description and drawing. The latter shows a hydraulic control device with a check valve in longitudinal section in FIG. 1, and a modification of the check valve in longitudinal section in FIG.

Beschreibung des AusführungsbeispielsDescription of the embodiment

Bei der in Figur 1 dargestellten Steuervorrichtung saugt eine Pumpe 10 aus einem Behälter 11 Druckmittel an, das über ein 3/2-Wegeventil 12 und ein Rückschlagventil 13 einem einfachwirkenden Arbeitszylinder 14 und über einen Leitungsabzweig 15 zwischen Arbeitszylinder 14 und Rückschlagventil 13 einem Sperrventil 16 zugeführt wird. Der Arbeitszylinder 14 hat einen Druckraum 17, in dem ein Kolben 18 mit Kolbenstange 19 geführt ist. Vom Sperrventil 16 führt eine Rücklaufleitung 20 zum Behälter 11.In the control device shown in FIG. 1, a pump 10 draws in pressure medium from a container 11, which is fed via a 3/2-way valve 12 and a check valve 13 to a single-acting working cylinder 14 and via a line branch 15 between working cylinder 14 and check valve 13 to a check valve 16 becomes. The working cylinder 14 has a pressure chamber 17 in which a piston 18 with a piston rod 19 is guided. A return line 20 leads from the shutoff valve 16 to the container 11.

Das Sperrventil 16 hat ein Ventilgehäuse 21, das in Längsrichtung von einer zweifach abgestuften Bohrung durchdrungen ist, deren Bohrungsabschnitte fortlaufend mit 22a bis 22c bezeichnet sind. Diese Bohrung geht von einer zylindrischen Vertiefung 23 aus, die wiederum in eine Stirnseite 24 des Gehäuses 21 eingelassen ist.The check valve 16 has a valve housing 21 which is penetrated in the longitudinal direction by a double-stepped bore, the bore sections of which are continuously designated 22a to 22c. This bore starts from a cylindrical recess 23, which in turn is embedded in an end face 24 of the housing 21.

In den mittleren Bohrungsabschnitt 22b sind vier Ringnuten 25 bis 28 eingelassen, wobei die Ringnut 25 im mittleren Bereich des Bohrungsabschnittes 22b angeordnet ist. Die Ringnut 28 befindet sich am Übergang zum Bohrungsabschnitt 22a, der mit einem Innengewinde versehen ist.Four annular grooves 25 to 28 are embedded in the central bore section 22b, the annular groove 25 being arranged in the central region of the bore section 22b. The annular groove 28 is located at the transition to the bore section 22a, which is provided with an internal thread.

Die zwischen den Ringnuten 25 und 27 bzw. 28 verlaufende Ringnut 26 ist breiter und tiefer ausgebildet und steht über einen das Gehäuse 21 durchdringenden Druckmittelkanal 29 mit dem zum Arbeitszylinder 14 bzw. zum Rückschlagventil 13 führenden Leitungsabzweig 15 in Verbindung. In den unteren Bohrungsabschnitt 22a ist ebenfalls eine Ringnut 30 eingelassen, die über einen das Gehäuse 21 durchdringenden Kanal 31 mit der zum Behälter 11 führenden Rücklaufleitung 20 verbunden ist.The annular groove 26 extending between the annular grooves 25 and 27 or 28 is wider and deeper and is connected via a pressure medium channel 29 penetrating the housing 21 to the line branch 15 leading to the working cylinder 14 or to the check valve 13. In the lower bore section 22a there is also an annular groove 30, which is connected via a channel 31 penetrating the housing 21 to the return line 20 leading to the container 11.

Das Ventilgehäuse 21 ist durch einen Stopfen 33 einseitig verschlossen. Dieser ist in den Bohrungsabschnitt 22b eingesetzt und liegt mit einem Absatz 34 geringeren Durchmessers an der durch den Übergang vom Bohrungsabschnitt 22b zum Bohrungsabschnitt 22c gebildeten Ringschulter 35 an. Zur Abdichtung ist dieser Absatz 34 mit einem Dichtring 36 umgeben.The valve housing 21 is closed on one side by a plug 33. This is inserted into the bore section 22b and, with a shoulder 34 of smaller diameter, lies against the annular shoulder 35 formed by the transition from the bore section 22b to the bore section 22c. To seal this paragraph 34 is surrounded by a sealing ring 36.

An der dem Bohrungsabschnitt 22c abgewandten Seite des Stopfens 33 liegen hintereinander angeordnete Zwischenringe 37, 38 an, an denen sich ein zylindrischer Ventileinsatz 39 abstützt. Dieser wird durch eine Einspannschraube 40 mit durchgehendem Innensechskant 40a festgesetzt. Diese ist in den Bohrungsabschnitt 22a eingeschraubt und liegt an der unteren Stirnseite 41 des Ventileinsatzes 39 an. Von dieser Stirnseite 41 geht im Ventileinsatz 39 eine axial verlaufende Bohrung 42 aus, die in eine achsgleich verlaufende Bohrung 43 größeren Durchmessers mündet. Diese Bohrung 43 geht von der am Zwischenring 38 anliegenden Stirnseite 44 des Ventileinsatzes 39 aus. Der Übergang der Bohrungen 42, 43 ist als Hauptventilsitz 45 ausgebildet. Im Bereich dieses Hauptventilsitzes 45 ist in der Bohrung 43 eine Ringnut 46 angeordnet, von der mehrere radial verlaufende Bohrungen 47 ausgehen, die den Ventileinsatz 39 durchdringen und mit der Ringnut 26 im Ventilgehäuse 21 in Verbindung stehen.On the side of the plug 33 facing away from the bore section 22c there are intermediate rings 37, 38 arranged one behind the other, on which a cylindrical valve insert 39 is supported. This is fixed by a clamping screw 40 with a continuous hexagon socket 40a. This is screwed into the bore section 22a and bears against the lower end face 41 of the valve insert 39. An axially extending bore 42 extends from this end face 41 in the valve insert 39 and opens into an axially aligned bore 43 of larger diameter. This bore 43 starts from the end face 44 of the valve insert 39 resting on the intermediate ring 38. The transition of the bores 42, 43 is designed as a main valve seat 45. In the area of this main valve seat 45, an annular groove 46 is arranged in the bore 43, from which a plurality of radially extending bores 47 extend, which penetrate the valve insert 39 and are connected to the annular groove 26 in the valve housing 21.

In die Wandung der Bohrung 42 ist ebenfalls eine Ringnut 49 eingelassen, deren dem Ventilsitz zugewandter Abschnitt 50 sich kegelförmig zur Bohrung 43 hin verjüngt, ohne bis an den Hauptventilsitz 45 heranzureichen.In the wall of the bore 42 is also an annular groove 49, the portion 50 facing the valve seat tapers conically towards the bore 43 without reaching to the main valve seat 45.

In den Ventileinsatz 39 ist von der Bohrung 43 aus ein Sitzventilkörper 51 eingesetzt. Dieser hat einen sich verjüngenden Abschnitt, der als Ventilkegel 52 mit dem Hauptventilsitz 45 zusammenwirkt. Von dem Ventilkegel 52 geht ein zylindrischer Fortsatz 53 aus, der in die Ringnut 49 ragt und dort in einen Anstieg 54 übergeht. Dieser Anstieg 54 weitet sich kegelförmig bis auf den Durchmesser der Bohrung 42 aus. Der Anstieg 54 ist so ausgebildet, daß sein größter Durchmesser im Bereich der Bohrung 42 liegt, wenn der Ventilkegel 52 am Hauptventilsitz 45 anliegt.A seat valve body 51 is inserted into the valve insert 39 from the bore 43. This has a tapered section which interacts as a valve cone 52 with the main valve seat 45. A cylindrical extension 53 extends from the valve cone 52 and protrudes into the annular groove 49 and merges there into an increase 54. This rise 54 widens conically to the diameter of the bore 42. The rise 54 is designed such that its largest diameter lies in the area of the bore 42 when the valve cone 52 abuts the main valve seat 45.

An den Anstieg 54 schließt sich ein kurzer, zylindrischer Abschnitt 55 an, der bei vorbeschriebener Lage des Sitzventilkörpers 51 in den der Stirnseite 41 zugewandten Abschnitt der Bohrung 42 ragt. Dieser zylindrische Abschnitt 55 geht in einen sich verjüngenden Feinsteuerkegel 56 über, der durch die Bohrung 42 bis in den Bohrungsabschnitt 22a ragt.The rise 54 is followed by a short, cylindrical section 55 which, when the poppet valve body 51 is in the position described above, projects into the section of the bore 42 facing the end face 41. This cylindrical section 55 merges into a tapered fine control cone 56 which projects through the bore 42 into the bore section 22a.

In die den Zwischenringen 37, 38 zugewandte Stirnseite 58 des Sitzventilkörpers 51 ist eine zylindrische Vertiefung 59 eingelassen, von der eine achsgleich verlaufende kleinere Längsbohrung 60 ausgeht. Der Grund der Längsbohrung 60 ist zur Stirnseite 63 hin kegelförmig ausgebildet und dient als Ventilsitz 61, der in eine gegenläufige, kegelförmige Vertiefung 62 übergeht, die sich bis zur gegenüberliegenden Stirnseite 63 des Sitzventilkörpers 51 aufweitet.A cylindrical recess 59 is embedded in the end face 58 of the seat valve body 51 facing the intermediate rings 37, 38, from which a smaller longitudinal bore 60 extending in the same axis extends. The base of the longitudinal bore 60 is conical towards the end face 63 and serves as a valve seat 61, which merges into an opposing, conical recess 62 which widens up to the opposite end face 63 of the seat valve body 51.

In die Längsbohrung 60 sind zwei Ringnuten 64, 65 eingelassen, von denen die obere Ringnut 64 im Bereich der Ringnut 47 des Ventileinsatzes 39 verläuft. Die untere Ringnut 65 liegt am Übergang der Längsbohrung 60 zum Ventilsitz 61.Two annular grooves 64, 65 are embedded in the longitudinal bore 60, of which the upper annular groove 64 extends in the region of the annular groove 47 of the valve insert 39. The lower annular groove 65 lies at the transition the longitudinal bore 60 to the valve seat 61.

Im Sitzventilkörper ist eine weitere Längsbohrung 66 angeordnet, die von der Stirnseite 58 ausgeht und exzentrisch und achsparallel zur Längsbohrung 60 verläuft. Diese weitere Längsbohrung 66 ragt bis in den Bereich der Ringnut 64 und ist mit dieser verbunden. Durch eine den Sitzventilkörper 51 durchdringende Drosselbohrung 67 sind die exzentrisch angeordnete Längsbohrung 66 und die Ringnut 47 im Ventileinsatz 39 miteinander verbunden. Über die exzentrische Längsbohrung 66 besteht dann eine Verbindung zu einem Druckraum 68, der in der Bohrung 43 im Ventileinsatz 39 zwischen dem Stopfen 33 und dem Sitzventilkörper 51 ausgebildet ist.A further longitudinal bore 66 is arranged in the seat valve body, which extends from the end face 58 and extends eccentrically and axially parallel to the longitudinal bore 60. This further longitudinal bore 66 extends into the area of the annular groove 64 and is connected to it. The eccentrically arranged longitudinal bore 66 and the annular groove 47 in the valve insert 39 are connected to one another by a throttle bore 67 penetrating the seat valve body 51. Via the eccentric longitudinal bore 66 there is then a connection to a pressure chamber 68 which is formed in the bore 43 in the valve insert 39 between the plug 33 and the seat valve body 51.

In die Längsbohrung 60 des Sitzventilkörpers 51 ist ein zylindrisches Vorsteuerventilglied 70 eingesetzt, das einen sich kegelförmig verjüngenden Abschnitt hat, der als Vorsteuerventilkegel 71 mit dem Ventilsitz 61 zusammenwirkt. Ein an den Vorsteuerventilkegel anschließender Zylinderabschnitt 72 geringeren Druchmessers ragt in den Bohrungsabschnitt 22a bis in die Nähe der Vertiefung 23 und stößt dort gegen den Stößel 73 eines Proportionalmagneten 69. Dieser Proportionalmagnet 69 liegt an der Stirnseite 24 des Ventilgehäuses 21 an und verschließt dieses. Durch einen in die Vertiefung 23 eingelegten Dichtring 74 wird die Verbindung abgedichtet.In the longitudinal bore 60 of the seat valve body 51, a cylindrical pilot valve member 70 is inserted, which has a conically tapering section which interacts as a pilot valve cone 71 with the valve seat 61. A cylinder section 72 of smaller diameter adjoining the pilot valve cone projects into the bore section 22a as far as the vicinity of the recess 23 and abuts there against the tappet 73 of a proportional magnet 69. This proportional magnet 69 lies against the end face 24 of the valve housing 21 and closes it. The connection is sealed by a sealing ring 74 inserted into the recess 23.

Die Längsbohrung 60 des Sitzventilkörpers 51 ist durch einen Stopfen 75 einseitig verschlossen. Dieser ist in die Vertiefung 59 eingesetzt und ragt mit einem Absatz 76 geringeren Durchmessers in die Längsbohrung 60. In eine im Absatz 76 angeordnete Ringnut 77 ist zur Abdichtung ein Dichtring 78 eingelegt, der an der Wandung der Langsbohrung 60 anliegt. Mit einem in eine entsprechende Ringnut 79 in der Vertiefung 59 eingesetzten Sicherungsring 80 wird der Stopfen 75 festgesetzt. Dieser ist so ausgebildet, daß zwischen dem Absatz 76 und dem Vorsteuerventilglied 70 ein Druckraum 81 in der Längsbohrung 60 entsteht, wenn das Vorsteuerventilglied 70 mit seinem Vorsteuerventilkegel 71 am Ventilsitz 61 anliegt.The longitudinal bore 60 of the seat valve body 51 is closed on one side by a plug 75. This is inserted into the recess 59 and projects with a shoulder 76 of smaller diameter into the longitudinal bore 60. In an annular groove 77 arranged in the shoulder 76, a sealing ring 78 is inserted for sealing, which bears against the wall of the longitudinal bore 60. The plug 75 is fixed in place with a retaining ring 80 inserted into a corresponding annular groove 79 in the recess 59. This is designed so that between the paragraph 76 and the pilot valve member 70, a pressure chamber 81 is formed in the longitudinal bore 60 when the pilot valve member 70 bears against the valve seat 61 with its pilot valve cone 71.

Von diesem Druckraum 81 ausgehend ist in dem Vorsteuerventilglied 70 eine Längsbohrung 82 angeordnet, die bis in den Zylinderabschnitt 72 ragt. Im Bereich der Vertiefung 62 des Sitzventilkörpers 51 ist die Längsbohrung 82 mit einer den Zylinderabschnitt 72 durchdringenden, querverlaufenden Drosselbohrung 83 verbunden.Starting from this pressure chamber 81, a longitudinal bore 82 is arranged in the pilot valve member 70, which extends into the cylinder section 72. In the region of the recess 62 of the seat valve body 51, the longitudinal bore 82 is connected to a transverse throttle bore 83 which penetrates the cylinder section 72.

Am Außenumfang des Vorsteuerventilgliedes 70 ist eine Ringnut 84 ausgebildet, die im Bereich der Ringnut 65 des Sitzventilkörpers 51 angeordnet ist. Von dieser Ringnut 84 gehen Feinsteuerkerben 85 mit sich verjüngendem Querschnitt aus, die sich bis zur Ringnut 64 hin erstrecken. Diese Feinsteuerkerben 85 sind so ausgebildet daß sie die Ringnut 64 gerade noch nicht erreichen, wenn der Vorsteuerventilkegel 71 am Ventilsitz 61 anliegt.An annular groove 84 is formed on the outer circumference of the pilot valve member 70 and is arranged in the region of the annular groove 65 of the seat valve body 51. Fine control notches 85 with a tapering cross-section extend from this annular groove 84 and extend as far as the annular groove 64. These fine control notches 85 are designed so that they just do not reach the annular groove 64 when the pilot valve cone 71 abuts the valve seat 61.

In das Ventilgehäuse 21 ist durch Einschrauben in den Bohrungsabschnitt 22a eine etwa becherförmige Einstellschraube 87 eingesetzt, deren Boden 88 der Einspannschraube 40 zugewandt ist, ohne diese zu erreichen. Vom Boden 88 geht ein zylindrischer Fortsatz 89 aus, der in einen Kegelstumpf 90 übergeht. Dieser ragt bis in die kegelförmige Vertiefung 62 des Sitzventilkörpers 51. Der zylindrische Fortsatz 89 und der Kegelstumpf 90 sind zur Durchführung des Zylinderabschnittes 72 des Vorsteuerventilgliedes 70 in axialer Richtung von zwei ineinander übergehenden Bohrungen 91, 92 durchdrungen. Die Bohrung 91 kleineren Durchmessers verläuft im Kegelstumpf 90, ihr Durchmesser ist größer als der des Zylinderabschnittes 72. Die Bohrung 92 größeren Durchmessers ist im zylindrischen Fortsatz 89 ausgebildet und geht von dem als Innensechskant ausgebildeten Innenraum 93 der Einstellschraube aus.An approximately cup-shaped adjusting screw 87 is inserted into the valve housing 21 by screwing it into the bore section 22a, the bottom 88 of the adjusting screw facing the clamping screw 40 without reaching it. A cylindrical extension 89 extends from the bottom 88 and merges into a truncated cone 90. This protrudes into the conical recess 62 of the seat valve body 51. The cylindrical extension 89 and the truncated cone 90 are penetrated in the axial direction by two merging bores 91, 92 for the passage of the cylinder section 72 of the pilot valve member 70. The bore 91 of smaller diameter runs in the truncated cone 90, its diameter is larger than that of the cylinder section 72. The bore 92 of larger diameter is formed in the cylindrical extension 89 and starts from the interior 93 of the adjusting screw, which is designed as a hexagon socket.

Der Kegelstumpf 90 ist so ausgebildet, daß sich die Drosselbohrung 83 innerhalb der Vertiefung 62 und außerhalb der Bohrung 91 des Kegelstumpfes 90 befindet, wenn sowohl der Vorsteuerventilkegel 71 am Ventilsitz 61 als auch der Ventilkegel 52 am Hauptventilsitz 45 anliegen.The truncated cone 90 is designed such that the throttle bore 83 is located within the recess 62 and outside the bore 91 of the truncated cone 90 when both the pilot valve cone 71 abuts the valve seat 61 and the valve cone 52 on the main valve seat 45.

Am Grund der Bohrung 92 stützt sich das eine Ende einer Druckfeder 94 ab, die den Zylinderabschnitt 72 des Vorsteuerventilgliedes 70 umfasst und deren entgegengesetztes Ende an einem Druckring 95 anliegt. Dieser Druckring 95 umfaßt den Zylinderabschnitt 72 in der Nähe der dem Stößel 73 zugewandten Stirnseite und wird durch ein Kugelsegment 96 und einen Sicherungsring 97, der in eine Ringnut 98 im Zylinderabschnitt 72 eingelegt ist, gegen Abschieben gesichert.At the bottom of the bore 92, one end of a compression spring 94 is supported, which comprises the cylinder section 72 of the pilot valve member 70 and whose opposite end abuts a pressure ring 95. This pressure ring 95 encompasses the cylinder section 72 in the vicinity of the end face facing the plunger 73 and is secured against being pushed off by a ball segment 96 and a locking ring 97 which is inserted into an annular groove 98 in the cylinder section 72.

Wenn sich das 3/2-Wege-Ventil 12 in seiner in Figur 1 dargestellten Neutralstellung I befindet, ist das Sperrventil 16 bei nicht erregtem Proportionalmagneten 69 geschlossen. Durch die Wirkung der Druckfeder 94 wird der Zylinderabschnitt 72 und damit das Vorsteuerventilglied 70 nach unten gezogen, so daß der Vorsteuerventilkegel 71 am Ventilsitz 61 anliegt. Damit wird auch der Sitzventilkörper 51 nach unten gezogen, so daß dessen Ventilkegel 52 am Hauptventilsitz 45 anliegt. Damit ist die Ringnut 46 bzw. die Bohrung 43 gegen die Bohrung 42 bzw. die Ringnut 49 abgedichtet. Druckmittel aus dem Druckraum 17 des Arbeitszylinders 14 gelangt dann über den Leitungsabzweig 15 und den Druckmittelkanal 29 über die Bohrungen 47 in die Ringnut 46. Das Rückschlagventil 13 verhindert einen Druckmittelstrom vom Arbeitszylinder 14 zum 3/2-Wege-Ventil 12. Der sich in der Ringnut 46 aufbauende Druck wirkt über die Drosselbohrung 67 und die Bohrung 66 auch im Druckraum 68 sowie in der Ringnut 64 des Sitzventilkörpers 51. Diese Ringnut ist durch das Vorsteuerventilglied 70 gegen die Ringnut 65 abgedichtet. Weiterhin ist die Ringnut 49 im Ventileinsatz 39 durch den in der Bohrung 42 befindlichen zylindrischen Abschnitt 55 des Feinsteuerkegels 56 gegen die Ringnut 30 und damit die Rücklaufleitung 20 abgedichtet.When the 3/2-way valve 12 is in its neutral position I shown in FIG. 1, the check valve 16 is closed when the proportional magnet 69 is not energized. The action of the compression spring 94 causes the cylinder section 72 and thus the pilot valve member 70 to be pulled down, so that the pilot valve cone 71 bears against the valve seat 61. This also pulls the seat valve body 51 downward, so that its valve cone 52 abuts the main valve seat 45. The annular groove 46 or the bore 43 is thus sealed against the bore 42 or the annular groove 49. Pressure medium from the pressure chamber 17 of the working cylinder 14 then passes through the line branch 15 and the pressure medium channel 29 through the bores 47 into the annular groove 46. The check valve 13 prevents a pressure medium flow from the working cylinder 14 to the 3/2-way valve 12 Ring groove 46 build-up pressure acts via the throttle bore 67 and the bore 66 also in the pressure chamber 68 and in the annular groove 64 of the seat valve body 51. This annular groove is sealed against the annular groove 65 by the pilot valve member 70. Furthermore, the annular groove 49 in the valve insert 39 is sealed against the annular groove 30 and thus the return line 20 by the cylindrical section 55 of the fine control cone 56 located in the bore 42.

Der Sitzventilkörper 51 wird demzufolge zusätzlich durch die Wirkung des Druckes im Druckraum 68 gegen den Hauptventilsitz 45 des Ventileinsatzes 39 gepreßt. Diese Anpreßkraft wird vermindert durch die Kraft aufgrund der Wirkung des Druckes in den Ringnuten 26 und 46 auf die Ringfläche zwischen Außenumfang des Sitzventilkörpers 51 und dem wirksamen Dichtumfang am Hauptventilsitz 45.The seat valve body 51 is therefore additionally pressed by the action of the pressure in the pressure chamber 68 against the main valve seat 45 of the valve insert 39. This contact pressure is reduced by the force due to the effect of the pressure in the ring grooves 26 and 46 on the ring surface between the outer circumference of the seat valve body 51 and the effective sealing circumference on the main valve seat 45.

Der Druck in der Rücklaufleitung 20 (Druck im Behälter 11) herrscht durch die Verbindung über den Kanal 31 auch in der Ringnut 30. Von dort besteht am Kegelstumpf 90 vorbei über die Drosselbohrung 83 eine Verbindung zur Längsbohrung 82 im Vorsteuerventilglied 70 und damit zum Druckraum 81. Über den Ringraum zwischen Bohrung 91 und Zylinderabschnitt 72 besteht weiterhin eine Verbindung zum Innenraum 93 der Einstellschraube 87.The pressure in the return line 20 (pressure in the container 11) prevails through the connection via the channel 31 also in the annular groove 30. From there past the truncated cone 90 via the throttle bore 83 there is a connection to the longitudinal bore 82 in the pilot valve member 70 and thus to the pressure chamber 81 There is still a connection to the interior 93 of the adjusting screw 87 via the annular space between the bore 91 and the cylinder section 72.

Die Leckverluste in Schließstellung des Sperrventils 16 vom Bereich hohen Druckes (Arbeitsdruck im Druckraum 17) gegen den Bereich geringen Druckes (Rücklaufleitung 20, Rücklaufdruck) sind aufgrund der mehrfachen Dichtstellen und wegen der Sitzventilbauweise sehr gering.The leakage losses in the closed position of the shut-off valve 16 from the area of high pressure (working pressure in the pressure chamber 17) to the area of low pressure (return line 20, return pressure) are very low due to the multiple sealing points and the seat valve design.

Wird der Proportionalmagnet 69 erregt, wird das Vorsteuerventilglied 70 über den Zylinderabschnitt 72 vom Stößel 73 nach oben bewegt. Der Vorsteuerventilkegel 71 hebt sich vom Ventilsitz 61 ab und die Feinsteuerkerben 85 gelangen in den Bereich der Ringnut 64. Das im Druckraum 68 unter Druck stehende Druckmittel kann dann über die Bohrung 66, die Ringnut 64 und die Feinsteuerkerben 85 in die Ringnut 65 gelangen. Von dort besteht am geöffneten Ventilsitz 61 und dem Vorsteuerventilkegel 71 vorbei eine Verbindung zur Vertiefung 62, die am Kegelstumpf 90 vorbei mit der Ringnut 30 verbunden ist. In Abhängigkeit vom Öffnungsquerschnitt (Eintauchtiefe der Feinsteuerkerben 85 in den Bereich der Ringnut 64) fällt der Druck im Druckraum 68. Dieser Druck stellt sich entsprechend dem Verhältnis des Drosselquerschnittes an der Drossel 67 und dem Öffnungsquerschnitt der Feinsteuerkerben 85 ein. Fällt bei entsprechend weit nach oben geschobenem Vorsteuerventilglied 70 der Druck im Druckraum 68 so weit, daß die Druckkräfte in der Ringnut 46 auf die Ringfläche zwischen Außenumfang des Sitzventilkörpers 51 und dem Dichtumfang am Hauptventilsitz 45 überwiegen, wird der Sitzventilkörper 51 vom Hauptventilsitz 45 abgehoben. Druckmittel aus der Ringnut 46 fließt dann am geöffneten Hauptventilsitz 45 vorbei in die Ringnut 49. Von dort besteht eine Verbindung am Feinsteuerkegel 56, der in die Ringnut 49 eintaucht, vorbei zum Innensechskant 40a. Druckmittel gelangt von dort zur Ringnut 30 und damit über die Rücklaufleitung 20 zum Behälter 11. Durch die Öffnungsbewegung des Sitzventilkörpers 51 verringert sich die relative Verschiebung zwischen diesem und dem Vorsteuerventilglied 70, so daß der Öffnungsquerschnitt an den Feinsteuerkerben 85 kleiner wird. Damit kann sich im Druckraum 68 über die Drossel 67 ein höherer Druck aufbauen. So wird die Öffnungsbewegung des Sitzventilkörpers 51 gebremst, bis sich ein Gleichgewichtszustand einstellt. Druckmittel aus der Ringnut 46 bzw. dem Leitungsabzweig 15 kann nun gleichmäßig abfließen, so daß die zu senkende Last am Arbeitszylinder 14 nicht vorauseilt, sowie schnarrende Geräusche und Ruckeln des Arbeitszylinders verhindert werden.If the proportional magnet 69 is excited, the pilot valve member 70 is moved upward by the plunger 73 via the cylinder section 72. The pilot valve cone 71 stands out from the valve seat 61 and the fine control notches 85 reach the area of the annular groove 64. The pressure medium under pressure in the pressure chamber 68 can then get into the annular groove 65 via the bore 66, the annular groove 64 and the fine control notches 85. From there, past the opened valve seat 61 and the pilot valve cone 71, there is a connection to the depression 62, which is connected to the annular groove 30 past the truncated cone 90. The pressure in the pressure chamber 68 drops as a function of the opening cross section (immersion depth of the fine control notches 85 in the region of the annular groove 64). This pressure is established in accordance with the ratio of the throttle cross section at the throttle 67 and the opening cross section of the fine control notches 85. Falls accordingly far pushed up pilot valve member 70, the pressure in the pressure chamber 68 so far that the compressive forces in the annular groove 46 predominate on the annular surface between the outer circumference of the seat valve body 51 and the sealing circumference on the main valve seat 45, the seat valve body 51 is lifted from the main valve seat 45. Pressure medium from the annular groove 46 then flows past the opened main valve seat 45 into the annular groove 49. From there, there is a connection past the fine control cone 56, which is immersed in the annular groove 49, to the hexagon socket 40a. Pressure medium passes from there to the annular groove 30 and thus via the return line 20 to the container 11. The opening movement of the seat valve body 51 reduces the relative displacement between the latter and the pilot valve member 70, so that the opening cross section at the fine control notches 85 becomes smaller. This allows a higher pressure to build up in the pressure chamber 68 via the throttle 67. Thus, the opening movement of the seat valve body 51 is braked until an equilibrium is reached. Pressure medium from the annular groove 46 or the line branch 15 can now flow out evenly, so that the load to be lowered on the working cylinder 14 does not lead ahead, and buzzing noises and jerking of the working cylinder are prevented.

Wird der Stößel 73 des Proportionalmagneten 69 nach unten bewegt, folgt das Vorsteuerventilglied 70 aufgrund der Wirkung der Druckfeder 94 dieser Bewegung. Der Öffnungsquerschnitt der Feinsteuerkerben 85 wird damit noch kleiner bzw. Null, so daß der Druck im Druckraum 68 ansteigt. Aufgrund dieses ansteigenden Druckes im Druckraum 68 und der mechanischen Führung des Vorsteuerventilgliedes 70 über den Vorsteuerventilkegel 71 am Ventilsitz 61 wird der Sitzventilkörper 51 ebenfalls nach unten bewegt (Folgesteuerung). Die Kraft, um das Vorsteuerventilglied 70 zu bewegen, ist in erster Linie abhängig von der Vorspannkraft der Druckfeder 94. Diese Vorspannkraft kann durch entsprechende Einschraubtiefe der Einstellschraube 88 variiert werden. Da die Drücke auf das Vorsteuerventilglied 70 über die Längsbohrung 82 und die Quer- bzw. Drosselbohrung 83 nahezu ausgeglichen sind, sind die hydraulischen Kräfte auf das Vorsteuerventilglied 70 entsprechend gering. Betätigungsweg und Betätigungskraft für das Vorsteuerventilglied 70 und damit für das Sperrventil 16 sind gering.If the plunger 73 of the proportional magnet 69 is moved downward, the pilot valve member 70 follows this movement due to the action of the compression spring 94. The opening cross section of the fine control notches 85 thus becomes even smaller or zero, so that the pressure in the pressure chamber 68 increases. Due to this increasing pressure in the pressure chamber 68 and the mechanical guidance of the pilot valve member 70 via the pilot valve cone 71 on the valve seat 61, the seat valve body 51 is also moved downward (sequential control). The force to move the pilot valve member 70 is primarily dependent on the biasing force of the compression spring 94. This biasing force can be varied by a corresponding screwing depth of the adjusting screw 88. Because the pressures on the pilot valve member 70 are almost balanced via the longitudinal bore 82 and the transverse or throttle bore 83, the hydraulic forces on the pilot valve member 70 are correspondingly low. Actuating travel and actuating force for the pilot valve member 70 and thus for the check valve 16 are small.

Ist der Druck im Druckraum 17 des Arbeitszylinders und damit in der Ringnut 46 zu gering, um das Sitzventilglied 51 in Öffnungsrichtung zu bewegen, kann dieses über das Vorsteuerventilglied aufgestoßen werden. Das Vorsteuerventilglied 70 wird dazu über den Stößel 73 des Proportionalmagneten 69 bis an den Absatz 76 des Stopfens 75 herangedrückt, so daß damit der Sitzventilkörper 51 bewegt wird.If the pressure in the pressure chamber 17 of the working cylinder and thus in the annular groove 46 is too low to move the seat valve member 51 in the opening direction, this can be pushed open via the pilot valve member. For this purpose, the pilot valve member 70 is pressed via the tappet 73 of the proportional magnet 69 up to the shoulder 76 of the plug 75, so that the seat valve body 51 is thus moved.

Zum Heben einer Last durch den Arbeitszylinder 14 wird das 3/2-Wege-Ventil 12 in die Schaltstellung II gebracht, so daß Druckmittel durch die Pumpe 10 über das in Durchgangsstellung befindliche Rückschlagventil 13 zum Arbeitszylinder 14 fließt.To lift a load through the working cylinder 14, the 3/2-way valve 12 is brought into the switching position II, so that pressure medium flows through the pump 10 via the check valve 13 in the through position to the working cylinder 14.

Das Sperrventil 16 zeichnet sich - wie bereits beschrieben - durch geringe erforderliche Betätigungskräfte und durch kurze Betätigungswege aus. Die hydraulischen Kräfte auf das Vorsteuerventilglied 70 sind nahezu ausgeglichen und Staudrücke auf das Vorsteuerventilglied 70 im Bereich des Ventilsitzes 71 bzw. der Einstellschraube 87 werden durch die jeweils kegelförmige Ausbildung des Sitzventilkörpers und der Einstellschraube 87 im Bereich des Kegelstumpfes 90 vermieden. Durch diese Umlenkung wird sowohl der Vorsteuervolumenstrom am Ventilsitz 71 vorbei als auch der Hauptvolumenstrom am geöffneten Feinsteuerkegel 56 vorbei zur Ringnut 30 umgelenkt, ohne daß es zu wesentlichen Staudrücken im Bereich des Zylinderabschnittes 72 im Innenraum 93 der Einstellschraube 87 kommt.The check valve 16 is characterized - as already described - by the low required actuation forces and by short actuation paths. The hydraulic forces on the pilot valve member 70 are almost equalized and dynamic pressures on the pilot valve member 70 in the region of the valve seat 71 or the adjusting screw 87 are avoided by the respective conical design of the poppet valve body and the adjusting screw 87 in the region of the truncated cone 90. As a result of this deflection, both the pilot control volume flow past the valve seat 71 and the main volume flow past the opened fine control cone 56 are diverted to the annular groove 30 without significant backpressures occurring in the area of the cylinder section 72 in the interior 93 of the adjusting screw 87.

Durch die räumliche Trennung von Ventilkegel 52 und Feinsteuerkegel 56 lassen sich diese ohne großen fertigungstechnischen Aufwand herstellen. Wird der Sitzventilkörper 51 nach oben bewegt, hebt der Ventilkegel 52 vom Hauptventilsitz 45 ab. Druckmittel aus der Ringnut 49 kann jedoch noch nicht abfließen, da der kurze zylindrische Abschnitt 55 am Feinsteuerkegel 56 noch innerhalb der Bohrung 42 angeordnet ist (Spaltdichtung). Erst wenn dieser kurze zylindrische Abschnitt 55 aus der Bohrung 42 austaucht, kann der Druckmittelstrom in Abhängigkeit von der Austauchtiefe des Feinsteuerkegels 56 zunehmen. Unstetigkeiten des Volumenstromverlaufes beim Öffnen des Sitzventilkörpers werden damit vermieden, da der Dichtstelle des Ventilkegels 52 am Hauptventilsitz 45 die Spaltdichtung am Feinsteuerkegel 55, 56 nachgeschaltet ist. Diese räumlich getrennten Ausbildungen von Hauptsteuerkegel (Ventilkegel 45) und Feinsteuerkegel 56 sind fertigungstechnisch günstiger als der direkte Übergang von Hauptsteuerkegel 45 zum Feinsteuerkegel in Zusammenhang mit nur einer Dichtstelle. Um Unstetigkeiten der Druchflußkennlinie zu vermeiden, sollten darüberhinaus der Durchmesser (wirksamer Durchmesser) am Hauptventilsitz 45 und am zylindrischen Abschnitt 55 gleich sein.Due to the spatial separation of valve cone 52 and fine control cone 56, these can be manufactured without great manufacturing outlay. If the seat valve body 51 is moved upward, the valve cone 52 lifts off the main valve seat 45. However, pressure medium cannot yet flow out of the annular groove 49, since the short cylindrical section 55 on the fine control cone 56 is still arranged within the bore 42 (gap seal). Only when this short cylindrical section 55 emerges from the bore 42 can the pressure medium flow increase as a function of the depth of immersion of the fine control cone 56. Discontinuities in the volume flow curve when the seat valve body is opened are thus avoided since the sealing point of the valve cone 52 on the main valve seat 45 is followed by the gap seal on the fine control cone 55, 56. These spatially separate designs of the main control cone (valve cone 45) and fine control cone 56 are cheaper in terms of production technology than the direct transition from the main control cone 45 to the fine control cone in connection with only one sealing point. In order to avoid discontinuities in the flow characteristic, the diameter (effective diameter) at the main valve seat 45 and at the cylindrical section 55 should also be the same.

In Figur 2 ist eine abgewandelte Ausführungsform des Sperrventils dargestellt, bei dem die Ausbildung des Vorsteuerventilgliedes 70a und die des Sitzventilkörpers 51a verändert sind. Das Vorsteuerventilglied 70a unterscheidet sich von dem zuvor beschriebenen durch eine verlängerte Längsbohrung 82a. Diese durchdringt auch den Zylinderabschnitt 72a fast vollständig, d.h. sie reicht bis in die Nähe seiner freien Stirnseite. Im Bereich des Bohrgrundes mündet in die Längsbohrung eine quer verlaufende Drosselbohrung 100, die diese mit dem Innenraum 93 der Einstellschraube 87 verbindet. In der Nähe des Überganges vom Vorsteuerventilkegel 71a zum Zylinderabschnitt 72a ist in letzterem die Drosselbohrung 83a ausgebildet, die ebenfalls in die Längsbohrung 82a mündet.FIG. 2 shows a modified embodiment of the check valve, in which the design of the pilot valve member 70a and that of the seat valve body 51a are changed. The pilot valve member 70a differs from that previously described by an elongated longitudinal bore 82a. This also penetrates the cylinder section 72a almost completely, ie it extends to the vicinity of its free end face. In the area of the drill base, a transverse throttle bore 100 opens into the longitudinal bore, which connects it to the interior 93 of the adjusting screw 87. In the vicinity of the transition from the pilot valve cone 71a to the cylinder section 72a, the throttle bore 83a is formed in the latter, which also opens into the longitudinal bore 82a.

Im Gegensatz zum zuvor beschriebenen Ausführungsbeispiel geht der zylindrische Abschnitt 55 am Sitzventilkörper 51a in einen zylindrischen Feinsteuerabschnitt 56a gleichen Durchmessers über. An dessen Außenumfang sind von der freien Stirnseite 63 ausgehend dreieckförmige Feinsteuerkerben 101 angeordnet, die zum zylindrischen Abschnitt 55 weisen und sich zu diesem hin verjüngen.In contrast to the exemplary embodiment described above, the cylindrical section 55 on the seat valve body 51a merges into a cylindrical fine control section 56a of the same diameter. On its outer circumference, starting from the free end face 63, triangular fine control notches 101 are arranged, which point towards the cylindrical section 55 and taper towards it.

Ein solcher Feinsteuerabschnitt ist fertigungstechnisch einfach zu handhaben und die Stetigkeit der Ventilkennlinie wird noch einmal verbessert. Beim Abheben des Ventilkegels 52 vom Hauptventilsitz 45 ist die Spaltlänge am Feinsteuerabschnitt erheblich größer als beim zylindrisch ausgebildeten Feinsteuerkegel nach Figur 1. Damit sind die Leckverluste über den Spalt wesentlich geringer.Such a fine control section is easy to handle in terms of production technology and the continuity of the valve characteristic is improved again. When the valve cone 52 is lifted off the main valve seat 45, the gap length at the fine control section is considerably larger than with the cylindrical fine control cone according to FIG. 1. The leakage losses through the gap are thus considerably less.

Durch die vorbeschriebene Ausbildung des Vorsteuerventilgliedes 70 bzw. 70a können sich Druckunterschiede auswirken, wodurch Unstetigkeiten in der Ventilkennlinie erzeugt werden. Durch den geringeren Durchmesser des Zylinderabschnittes 72 kann auf die Ringschulter im Bereich des Vorsteuerventilkegels 71 bzw. 71a eine Kraft wirken, die abhängig ist vom dort vorherrschenden Druck. Unterscheidet sich aufgrund der Strömungsdynamik der Druck an dieser Ringfläche von dem Druck an den beiden Stirnseiten, so sind die hydrostatischen Kräfte am Vorsteuerventilglied nicht ausgeglichen. Durch die Drosselbohrungen 83a und 100 nach Figur 2 können diese Kräfte ausgeglichen werden. Diese Drosselbohrungen sind dabei so dimensioniert, daß der Druck in der Längsbohrung 82 und damit im Druckraum 81 immer so groß ist, daß die hydrostatischen Kräfte auf das Vorsteuerventilglied 70 ausgeglichen sind. Der Druck in der Längsbohrung 82 ist ein Druck, der zwischen den Drücken im Bereich des Innenraums 93 und im Bereich der Vertiefung 62 liegt.Due to the above-described design of the pilot valve member 70 or 70a, pressure differences can have an effect, whereby discontinuities in the valve characteristic curve are generated. Due to the smaller diameter of the cylinder section 72, a force can act on the annular shoulder in the area of the pilot valve cone 71 or 71a, which is dependent on the pressure prevailing there. If, due to the flow dynamics, the pressure on this annular surface differs from the pressure on the two end faces, the hydrostatic forces on the pilot valve member are not balanced. These forces can be compensated for by the throttle bores 83a and 100 according to FIG. These throttle bores are dimensioned so that the pressure in the longitudinal bore 82 and thus in the pressure chamber 81 is always so great that the hydrostatic forces on the pilot valve member 70 are balanced. The pressure in the longitudinal bore 82 is a pressure that lies between the pressures in the area of the interior 93 and in the area of the depression 62.

Claims (11)

  1. Control device for the volumetric flow of a hydraulic working device, preferably of a power cylinder, having a shutoff valve (16) which has a seated valve body (51, 52a) which cooperates with a main valve seat (45), which is fixed to the housing, and in which there is arranged a pilot valve member (70, 70a) which is operationally connected to an operating device (69, 73) and cooperates under the force of a spring (94) with a valve seat (61) arranged in the seated valve body and controls the pressure in a pressure chamber (68) formed between the seated valve body and the valve housing (21, 33), the seated valve body being pressed by the action of this pressure against the main valve seat (45), characterized in that the pressure chamber (68) is permanently connected via a throttle point (67) with a constant cross-section to a pressure chamber (17) of the working device (14) and can be connected via a variable throttle point (64, 85) to a container (11) whose cross-section can be varied by the pilot valve member (70, 70a), in that the operating device cooperating with the pilot valve member (70, 70a) is a proportional magnet (69) built onto the shutoff valve, in that the seated valve body (51, 51a) has a fine-control spool (55, 56, 56a) which is spatially separated from the main valve seat (45), and in that the spring (94) acting on the pilot valve member (70, 70a) is supported fixed in the housing and loads the pilot valve member (70, 70a) and seated valve body (51, 51a) in the direction of their valve seats (61, 45).
  2. Control device according to Claim 1, characterized in that the throttle point (67) is constructed with a constant cross-section in the seated valve body (51, 51a).
  3. Control device according to Claim 1 or 2, characterized in that the cross-section of the variable throttle point (64, 85) is changed by a relative displacement of the pilot valve member (70, 70a) with respect to the seated valve body (51, 51a).
  4. Control device according to one of Claims 1 to 3, characterized in that the pilot valve member (70, 70a) can be displaced against the action of a compression spring (94) by the proportional magnet (69).
  5. Control device according to one of Claims 1 to 4, characterized in that the main valve seat (45) cooperating with the seated valve body (51, 51a) is arranged in a valve insert (39) fixed in the housing.
  6. Control device according to Claim 5, characterized in that the fine-control spool (55, 56, 56a) of the seated valve body (51, 51a) cooperates with a bore (42) in the valve insert (39) fixed in the housing.
  7. Control device according to one of Claims 1 to 6, characterized in that there are provided in the shutoff valve (16) means (90) for directing the volumetric flow which largely prevent dynamic pressures when the shutoff valve (16) is open.
  8. Control device according to one of Claims 1 to 7, characterized in that the spring (94) loading the pilot valve member (70, 70a) is arranged outside the seated valve body (51) and acts in a pulling fashion on the pilot valve member (70, 70a).
  9. Control device according to one of Claims 1 to 8, characterized in that the effective diameters of main valve seat (45) and fine-control spool (55) are of equal size.
  10. Control device according to Claim 9, characterized in that the effective diameters of the valve seat (71) and fine-control notches (85) on the pilot valve member (70, 70a) are of equal size.
  11. Control device according to Claims 1 to 10, characterized in that the pilot valve member (70a) merges downstream from the pilot valve cone (71a) via an annular shoulder into a cylindrical section (72a) of smaller diameter which projects through a bore (91) into the interior (93) of an adjusting screw (87) in which the spring (94) loading the pilot valve cone (71a) is arranged, and in that the pilot valve member (70a) has a longitudinal bore (82a) which opens into a pressure chamber (81) situated at the end face of the pilot valve member (70a) and which is connected via a first throttle bore (83a) to the flow channel in the region of the annular shoulder and, via a second throttle bore (100), to the interior (93) of the adjusting screw (87).
EP92118860A 1991-12-10 1992-11-04 Flow control device for a working fluid Expired - Lifetime EP0548513B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4140604 1991-12-10
DE4140604A DE4140604A1 (en) 1991-12-10 1991-12-10 CONTROL DEVICE FOR THE VOLUME FLOW OF A HYDRAULIC WORKING AGENT

Publications (2)

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EP0548513A1 EP0548513A1 (en) 1993-06-30
EP0548513B1 true EP0548513B1 (en) 1996-04-10

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EP92118860A Expired - Lifetime EP0548513B1 (en) 1991-12-10 1992-11-04 Flow control device for a working fluid

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US (1) US5290007A (en)
EP (1) EP0548513B1 (en)
DE (2) DE4140604A1 (en)
RU (1) RU2102635C1 (en)

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EP0548513A1 (en) 1993-06-30
RU2102635C1 (en) 1998-01-20
US5290007A (en) 1994-03-01
DE59205959D1 (en) 1996-05-15
DE4140604A1 (en) 1993-06-17

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