EP1381779A1 - Directional control valve comprising an internal pressure regulator - Google Patents

Directional control valve comprising an internal pressure regulator

Info

Publication number
EP1381779A1
EP1381779A1 EP02727817A EP02727817A EP1381779A1 EP 1381779 A1 EP1381779 A1 EP 1381779A1 EP 02727817 A EP02727817 A EP 02727817A EP 02727817 A EP02727817 A EP 02727817A EP 1381779 A1 EP1381779 A1 EP 1381779A1
Authority
EP
European Patent Office
Prior art keywords
piston
pressure
directional control
control valve
pressure compensating
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP02727817A
Other languages
German (de)
French (fr)
Other versions
EP1381779B1 (en
Inventor
Winfried RÜB
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bucher Hydraulics GmbH
Original Assignee
Bucher Hydraulics GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Bucher Hydraulics GmbH filed Critical Bucher Hydraulics GmbH
Publication of EP1381779A1 publication Critical patent/EP1381779A1/en
Application granted granted Critical
Publication of EP1381779B1 publication Critical patent/EP1381779B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
    • F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
    • F15B13/0416—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor with means or adapted for load sensing
    • F15B13/0417—Load sensing elements; Internal fluid connections therefor; Anti-saturation or pressure-compensation valves
    • F15B13/0418—Load sensing elements sliding within a hollow main valve spool
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/8593—Systems
    • Y10T137/86493—Multi-way valve unit
    • Y10T137/86574—Supply and exhaust
    • Y10T137/8667—Reciprocating valve
    • Y10T137/86694—Piston valve
    • Y10T137/86702—With internal flow passage
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/8593—Systems
    • Y10T137/87169—Supply and exhaust

Definitions

  • the invention relates to a directional valve with an internal pressure compensator according to the preamble of claim 1.
  • Such directional valves are advantageously used in mobile hydraulics to control hydraulic consumers in agricultural and construction vehicles.
  • a directional control valve of the type mentioned in the preamble of claim 1 is known from DE-Al-198 55 187.
  • the directional control valve has an internal pressure compensator which is designed as a hollow slide. This has a radial breakthrough that is permanently connected to a radial breakthrough of the valve piston.
  • the valve has a load-sensing ring channel that is continuously connected to a spring chamber of the pressure compensator.
  • a similar directional control valve is also known from DE-Al-198 36 564.
  • a pressure compensator is arranged within the slide piston designed as a hollow piston.
  • the implementation of an additional control edge means additional manufacturing effort.
  • the compensation of flow forces is always imperfect if the flows are different in size.
  • the hydraulic consumer is a differential cylinder
  • the flow rate of the hydraulic medium at the two working ports A and B of the directional control valve is inevitably different.
  • such differential cylinders can in turn have different ratios of the mass flows in the inflow and outflow.
  • the pressure compensator piston In the "neutral" position, the pressure compensator piston should assume a clearly closed position. However, this is often prevented by the build-up of uncontrollable pressures due to leakages. Leakages between those ring channels of the directional valve, which have different pressures, are inevitable and their size cannot be predicted due to manufacturing tolerances.
  • the invention has for its object to provide a directional control valve whose pressure compensator is insensitive to different flow forces caused by different flow rates and at the same time ensures that the hydraulic consumer cannot move in the "neutral" position.
  • FIG. 1 shows a sectional illustration of a directional valve piston with an internal pressure compensator in a valve housing
  • FIG. 3 shows a representation analogous to FIG. 1, but in a working position of the directional valve
  • valve housing 1 part of a valve housing is shown with the reference number 1, which has a longitudinal bore 2.
  • the valve housing 1 and also a directional valve piston 3 which is displaceable in the longitudinal bore 2 are symmetrically constructed in two axes.
  • the directional valve piston 3 is a hollow slide.
  • different annular channels are pierced from the longitudinal bore 2, namely a tank connection ring channel T in the center of symmetry, followed by further vertical channels from the vertical axis of symmetry S s towards the front side of the valve housing 1, namely to the left a working connection ring channel A and to the right is a working connection ring channel B.
  • These two working connection ring channels A, B are connected to the load connections of the directional control valve, which are usually referred to as "A" and "B".
  • the working connection ring channel B is followed by a pump pressure ring channel P, then a load-sensing ring channel LS and finally an end space ring channel E.
  • the same sequence of ring channels is also present to the left, but not in FIG. 1 shown.
  • the directional control valve piston 3 in turn has an axial bore 4, in which a pressure compensating piston 5 can be axially displaced against a pressure compensating spring 6.
  • the illustration in FIG. 1 shows the directional control valve piston 3 in the neutral position, in which there is neither a connection to the tank connection ring channel T nor to the pump pressure ring channel P from the working connection ring channels A and B.
  • the hydraulic consumer connected to the load connections of the directional control valve which are referred to as "A" and "B" as mentioned, is thus stationary.
  • the pressure compensating piston 5 is also a hollow slide, that is, it encloses an interior space 7 that is open against the vertical axis of symmetry S s , but on the other side has a closed end wall 8.
  • the directional valve piston 3 is also closed on the end face, for example by means of a screw-in closure cap 9.
  • the already mentioned pressure balance spring 6 is arranged between the closure cap 9 of the directional valve piston 3 and the end wall 8 of the pressure compensating piston 5.
  • the pressure compensating piston has 5 control ribs 10 on the left open side. These form extensions of the cylindrical part of the pressure compensating piston 5. In order to clarify their shape and position, a section line II-II is drawn in, the corresponding section being shown in FIG. 2. 2, the control ribs 10 are cut, while the end faces of the pressure compensating piston 5 lying in between are shown in a top view. The annular section-shaped spaces between the
  • Control ribs 10 are referred to as fine control notches and are provided with the reference number 11.
  • FIG. 1 Elements essential for the function of the directional control valve are additionally shown in FIG. 1.
  • the reference number 19 designates a control spring which acts on the directional control valve piston 3 from a drive (not shown).
  • Functionally essential are tank control grooves 20, which are milled into the lateral surface of the directional valve piston 3 and which, with a corresponding relative position of the directional valve piston 3, serve to
  • Valve housing 1 to allow the flow of the hydraulic medium from the working connection ring channel B or working connection ring channel A to the tank connection ring channel T, which characterizes the two working positions of the directional control valve. If, for example, the directional valve piston 3 is shifted to the right from the position shown in FIG. 1, then the connection between the working connection ring channel B and the tank connection ring channel T is established via the tank control grooves 20.
  • a first valve piston radial breakthrough 21 and a second valve piston radial breakthrough 22 are also essential in terms of their function, the functional significance of which is still to be discussed.
  • connection bores 23 are also arranged, through which a permanent connection between the load-sensing ring channel LS and the space surrounding the pressure compensator spring 6, which is referred to as the pressure compensator spring chamber 24, is produced. So that this connection exists at all positions of the pressure compensating piston 5 within the directional control valve piston 3, the inside diameter of the valve is, for example
  • Directional valve piston 3 in the area of the pressure compensator spring chamber 24 is larger than the outside diameter of the pressure compensator piston 5.
  • other means such as longitudinal grooves, can also be present in order to guarantee this permanent connection between the load-sensing ring channel LS and the pressure compensator spring chamber 24 .
  • the pressure prevailing in the load-sensing ring channel LS acts in the pressure compensator spring chamber 24, which, in cooperation with the pressure compensator spring 6, guarantees according to the invention that the pressure compensator piston 5 assumes a clear position in which the pressure compensator piston 5 adopts the working connection annular duct B. shuts off safely, which solves that part of the task that in the "neutral" position there can be no movement of the hydraulic consumer.
  • the pressure compensator spring chamber 24 is functionally a control pressure chamber. It is essential to the invention that there is no control edge between the load-sensing ring channel LS and the pressure compensator spring chamber 24, which could adversely affect the pressure in the pressure compensator spring chamber 24.
  • the circumferential line of the pressure compensating piston 5 acts as the first control edge of the pressure compensating piston 5 in the area of the fine control notches 10
  • the control edge is provided with the reference number 30 in FIGS. 1 and 2.
  • Essential to the invention is a feature known per se from the prior art, namely that the pressure compensating piston 5 has at least one radial opening 31 in its cylindrical casing.
  • several such radial openings 31 are present, which are evenly distributed over the circumference of the pressure compensating piston 5.
  • Each of the radial openings 31 has the shape of an elongated slot.
  • the radial openings 31 act as the second control edge of the pressure compensating piston 5. They are in permanent connection with the valve piston radial opening 22. If the pressure in the axial bore 4 of the directional control valve piston 3 and in the interior 7 of the pressure compensating piston 5 increases so high that the pressure force acting on the pressure compensator piston 5 is greater than the sum of the force of the pressure compensator spring 6 and that resulting from the pressure in the pressure compensator spring chamber 24 Pressure compensator piston 5 acting force, the pressure compensator piston 5 moves so far to the right against the pressure compensator spring 6 until the force is balanced again. At a sufficiently high pressure in the axial bore 4 of the directional control valve piston 3 and in the inner space 7 of the pressure compensator piston 5, the pressure compensator piston 5 moves to the right against the pressure compensator spring 6 until the axial bore 4 of the
  • a diameter d Dw is also shown, which denotes the outer diameter of the pressure compensating piston 5. This diameter d Dw determines the hydrostatic force effect, which is due to the
  • the directional control valve piston 3 shows a working position of the directional valve piston 3. Due to a drive present in such directional control valves, which is not shown in all the figures, the directional control valve piston 3 is displaced to the left within the valve housing 1. This means that there is flow from the pump pressure ring channel P to the working connection ring channel B. Hydraulic medium can now flow from the pump pressure ring channel P through the second valve piston radial opening 22 of the directional control valve piston 3 and through the
  • Pressure balance piston 5 within the directional control valve piston 3 adjusts itself in accordance with the difference in the force effects which arise from the pressures in the pump pressure ring channel P and in the load-sensing ring channel LS.
  • the pressure compensating piston 5 opens the connection between the valve piston radial opening 21 and the axial bore 4 of the directional control valve piston 3 via its control ribs 10, so that a certain discharge cross-section results at the valve piston radial opening 21. If the pressure in the working connection ring channel B, corresponding to the pressure at the corresponding load connection of the consumer, is high and the resulting pressure force on the pressure compensator piston 5 overcomes the sum of the pressure in the pressure compensator spring chamber 24 and the force of the pressure compensator spring 6, then the pressure builds up in the interior 7 of the pressure compensator piston 5 to the pressure in the working connection ring channel B and moves the pressure compensator piston 5 against the pressure compensator spring 6 as far to the right as is shown in FIG. 3.
  • the pressure compensator spring chamber 24 is then connected to the interior 7 of the pressure compensator piston 5.
  • the pressure in the load-sensing ring channel LS follows this value because of the connection from the interior 7 of the pressure compensating piston 5 via the connecting bores 23 to the load-sensing ring channel LS.
  • the movement of the consumer now takes place in a known manner through the action of a pump regulator, not shown.
  • the pump regulator raises the pump pressure so much that the throttle cross section of the second valve piston radial opening 22 des
  • a second step of the pressure compensator control takes place when the pressure in the working connection ring channel B, corresponding to the pressure at the corresponding load connection of the consumer, is lower than the pump pressure.
  • Through the draining Hydraulic medium drops the pressure in the interior 7 of the pressure compensator piston 5 so far that the pressure compensator piston 5 moves under the influence of the pressure compensator spring 6 in connection with the pressure in the pressure compensator spring chamber 24 until the control ribs 10 have the discharge cross-section at the valve piston radial breakthrough 21 have reduced until the pressure that has now accumulated again in the interior 7 of the pressure compensating piston 5 is in force equilibrium with the forces which result from the effect of the pressure in the pressure compensating spring chamber 24 and the pressure compensating spring 6.
  • Pressure compensator results when the largest effective opening cross-section for the radial opening 22 is given by the relative position of the second valve piston radial opening 22 of the directional valve piston 3 to the pump pressure ring channel P. If the inside diameter dj of the pressure compensating piston 5 is large, this results in a small axial flow velocity in the interior 7 of the pressure compensating piston 5 with correspondingly low jet forces. It has proven to be advantageous if the inner diameter d] is dimensioned such that the area d ⁇ ' ⁇ / 4 is approximately three to five times the area of the radial opening 22.
  • the pressure compensator spring chamber 24 is fundamentally and continuously connected to the load-sensing ring channel LS.
  • the pressure in the interior 7 of the pressure compensating piston 5 can vary depending on the working position of the directional valve piston 3. In the neutral position shown in FIG. 1, it is indefinite. In order to ensure that the interior 7 of the pressure compensating piston 5 also has a defined pressure in this position, it is advantageous to provide a pressure relief bore 40 through which, in the neutral position of the directional control valve piston 3, the axial bore 4 of the directional control valve piston 3 and thus also the interior 7 of the Pressure compensating piston 5 is connected to the tank connection ring channel T.
  • the interior 7 of the pressure compensating piston 5 can thus be connected to the tank connection ring channel T, but is only connected in the neutral position. Because the pressure in the tank connection ring channel T during operation of the consumer is generally lower than the pressure in the load-sensing ring channel LS, it is achieved that pressure compensating piston 5 assumes the desired unambiguous position not only because of the effect of the pressure compensating spring 6, but also because of the Pressure difference between the load-sensing ring channel LS and the tank connection ring channel T is still supported. Problems caused by leakage pressure losses cannot arise in this way.
  • An alternative way of achieving the desired unique position of the pressure compensating piston 5 in the neutral position by clearly defining the pressure in the interior 7 of the pressure compensating piston 5 is to connect the interior 7 to the load-sensing ring channel LS in the neutral position. Then the pressure compensator spring 6 alone determines the unique position of the pressure compensator piston 5 in the
  • connection of the interior 7 with the load-sensing ring channel LS is achieved according to the invention in that the valve piston radial opening 22 is given a different shape. 1 and 3, an annular groove 41 is shown by dashed lines, which connects directly to the valve piston radial opening 22. From Fig. 1 it can be seen that through this to the valve piston radial opening 22 annular groove 41 there is a connection from the interior 7 to the load-sensing ring channel LS, during which Fig. 3 can be seen that this annular groove 41 in the working position of the directional valve piston 3 is ineffective.
  • This solution according to the invention with the annular groove 41 is advantageous in particular with regard to the production costs.
  • the central part of the end face 12 has the shape of a very flat cone 50 with a tip angle of 150 to 170 degrees.
  • Axis of symmetry S s parallel ring surface 51, which then merges into an ellipsoidal surface 52 which surrounds the cross-sectional widening 13.
  • This particular shape has an advantageous influence on the flow in the axial bore 4 and represents means for deflecting the flow.
  • an inflowing or outflowing jet generates an undesirable resulting axial force component when the inflow and outflow
  • FIG. 5 shows an embodiment variant for that end of the pressure compensating piston 5 at which the control edge 30 is located.
  • Alternative configurations are shown in FIGS. 6 a) to 6 c). These figures show the 360 ° development of the outer surface of the pressure compensating piston 5 in the area of the fine control notches 11. 6 a) corresponds to the embodiment according to FIGS. 1 to 3, while FIGS. 6 b) and 6 c) show alternative embodiments.
  • Fig. 6 b) shows triangular spaces and Fig. 6 c) circular segment-shaped spaces.
  • 5 and 6 a) to 6 c) show means on the control edge 30 of the pressure compensating piston 5, with which the dependence of the effective opening cross section when moving the pressure compensating piston 5 can be influenced in an advantageous manner.
  • the various options can also be combined.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Safety Valves (AREA)
  • Gas Exhaust Devices For Batteries (AREA)

Abstract

A directional control valve includes a pressure regulator piston configured as a hollow slide with a radial passage positioned in such a way that a connection from the internal chamber of the pressure regulator piston to a pump pressure annular channel (P) can be regulated by the radial passage and a second radial passage of a directional control valve piston. The second radial passage constitutes a control edge, which is used to regulate the connection from the internal chamber to a load sensing annular channel (LS). An annular groove, which in the neutral position forms a connection from the internal chamber to the load sensing annular channel (LS), is joined to the second radial passage. The pressure regulator is impervious to different flow forces caused by different mass fluxes and ensures that the hydraulic consumer is prevented from moving in the neutral position.

Description

Wegeventil mit innenliegender DruckwaageDirectional control valve with internal pressure compensator
Die Erfindung bezieht sich auf ein Wegeventil mit innenliegender Druckwaage gemäß dem Oberbegriff des Anspruchs 1.The invention relates to a directional valve with an internal pressure compensator according to the preamble of claim 1.
Solche Wegeventile werden vorteilhaft in der Mobilhydraulik zur Ansteuerung von hydraulischen Verbrauchern bei Landwirtschafts- und Baufahrzeugen verwendet.Such directional valves are advantageously used in mobile hydraulics to control hydraulic consumers in agricultural and construction vehicles.
Ein Wegeventil der im Oberbegriff des Anspruchs 1 genannten Art ist aus der DE-Al-198 55 187 bekannt. Das Wegeventil weist eine innenliegende Druckwaage auf, die als Hohlschieber ausgebildet ist. Dieser weist einen Radialdurchbruch auf, der dauernd mit einem Radialdurchbruch des Ventilkolbens in Verbindung steht. Außerdem weist das Ventil einen Load-Sensing-Ringkanal auf, der dauernd mit einem Federraum der Druckwaage in Verbindung steht. Durch die Ausbildung des Wegeventils kann der Druckabfall über einer Meßblende konstant gehalten werden.A directional control valve of the type mentioned in the preamble of claim 1 is known from DE-Al-198 55 187. The directional control valve has an internal pressure compensator which is designed as a hollow slide. This has a radial breakthrough that is permanently connected to a radial breakthrough of the valve piston. In addition, the valve has a load-sensing ring channel that is continuously connected to a spring chamber of the pressure compensator. By designing the directional valve, the pressure drop across a measuring orifice can be kept constant.
Ein ähnliches Wegeventil ist auch aus DE-Al-198 36 564 bekannt. Auch hier ist innerhalb des als Hohlkolben ausgebildeten Schieberkolbens eine Druckwaage angeordnet. Um das bestehende Problem der Wirkung von Strömungskräften auf dasA similar directional control valve is also known from DE-Al-198 36 564. Here, too, a pressure compensator is arranged within the slide piston designed as a hollow piston. To the existing problem of the effect of flow forces on the
Verhalten des Wegeventils zu lösen, wird hier vorgeschlagen, am Druckwaagekolben eine zweite Steuerkante vorzusehen, mit der eine zusätzliche Druckmittelströmung zum Arbeitsanschluß erzeugbar ist. Durch diese Kompensationsströmung sollen die Strömungskräfte auf den Druckwaagekolben und auf den Schieberkolben minimiert werden. Damit soll insbesondere das Ansprechverhalten des Wegeventils, etwa beim Einleiten von Hebe- und Senkvorgängen bei Krafthebern, verbessert werden.To solve the behavior of the directional valve, it is proposed here to provide a second control edge on the pressure compensating piston, with which an additional pressure medium flow to the work connection can be generated. This compensation flow is intended to minimize the flow forces on the pressure compensating piston and on the slide piston. In particular, this is intended to improve the response behavior of the directional control valve, for example when initiating lifting and lowering processes in power jacks.
Grundsätzlich bedeutet die Verwirklichung einer zusätzlichen Steuerkante einen fabrikatorischen Mehraufwand. Die Kompensation von Strömungskräften ist immer dann auch unvollkommen, wenn die Strömungen hinsichtlich ihrer Größe unterschiedlich sind. So ist beispielsweise dann, wenn der hydraulische Verbraucher ein Differentialzylinder ist, zwangsläufig der Mengenstrom des Hydraulikmediums an den beiden Arbeitsanschlüssen A und B des Wegeventils unterschiedlich. Hinzu kommt, daß ihrerseits solche Differentialzylinder unterschiedliche Verhältnisse der Mengenströme im Zu- und Abfluß aufweisen können. Daneben besteht aber noch ein weiteres Problem: In der Stellung "Neutral" soll der Druckwaagekolben eine eindeutige Schließstellung einnehmen. Diese wird aber oftmals dadurch verhindert, daß sich infolge von Leckagen unbeherrschbare Drücke aufbauen. Leckagen zwischen jenen Ringkanälen des Wegeventils, die unterschiedliche Drücke aufweisen, sind unvermeidlich und infolge von Fabrikationstoleranzen in ihrer Größe nicht vorhersehbar. Im schlimmsten Fall kann es folglich zu einer Bewegung des Verbrauchers kommen, obwohl dieser still stehen soll. Der Erfindung liegt die Aufgabe zugrunde, ein Wegeventil zu schaffen, dessen Druckwaage unempfindlich gegen durch unterschiedliche Mengenströme verursachte unterschiedliche Strömungskräfte ist und gleichzeitig sicherstellt, daß es in der Stellung "Neutral" nicht zu einer Bewegung des hydraulischen Verbrauchers kommen kann.Basically, the implementation of an additional control edge means additional manufacturing effort. The compensation of flow forces is always imperfect if the flows are different in size. For example, if the hydraulic consumer is a differential cylinder, the flow rate of the hydraulic medium at the two working ports A and B of the directional control valve is inevitably different. In addition, such differential cylinders can in turn have different ratios of the mass flows in the inflow and outflow. But there is also another problem: In the "neutral" position, the pressure compensator piston should assume a clearly closed position. However, this is often prevented by the build-up of uncontrollable pressures due to leakages. Leakages between those ring channels of the directional valve, which have different pressures, are inevitable and their size cannot be predicted due to manufacturing tolerances. In the worst case, the consumer may move, even though the consumer is supposed to stand still. The invention has for its object to provide a directional control valve whose pressure compensator is insensitive to different flow forces caused by different flow rates and at the same time ensures that the hydraulic consumer cannot move in the "neutral" position.
Die genannte Aufgabe wird erfindungsgemäß durch die Merkmale des Anspruchs 1 gelöst. Vorteilhafte Weiterbildungen ergeben sich aus den abhängigen Ansprüchen.According to the invention, the stated object is achieved by the features of claim 1. Advantageous further developments result from the dependent claims.
Nachfolgend wird ein Ausfuhrungsbeispiel der Erfindung anhand der Zeichnung näher erläutert.An exemplary embodiment of the invention is explained in more detail below with reference to the drawing.
Es zeigen: Fig. 1 eine Schnittdarstellung eines Wegeventilkolbens mit innenliegender Druckwaage in einem Ventilgehäuse,1 shows a sectional illustration of a directional valve piston with an internal pressure compensator in a valve housing,
Fig. 2 eine teilgeschnitte Ansicht eines Druckwaagekolbens,2 is a partial sectional view of a pressure compensating piston,
Fig. 3 eine Darstellung analog der Fig. 1, jedoch in einer Arbeitstellung des Wegeventils,3 shows a representation analogous to FIG. 1, but in a working position of the directional valve,
Fig. 4 ein Detail einer Stirnfläche im Wegeventilkolben,4 shows a detail of an end face in the directional valve piston,
Fig. 5 eine alternative Ausführung eines Endes des Druckwaagekolbens, und5 shows an alternative embodiment of one end of the pressure compensating piston, and
Fig. 6a bis c weitere Ausgestaltungsformen dazu.6a to c further embodiments.
In der Fig. 1 ist mit der Bezugszahl 1 ein Teil eines Ventilgehäuses gezeigt, das ein Längsbohrung 2 aufweist. Mit einer waagerechten Symmetrieachse Sw und einer senkrechten Symmetrieachse Ss ist angedeutet, daß das Ventilgehäuse 1 und auch ein in der Längsbohrung 2 verschiebbarer Wegeventilkolben 3 zweiachsig symmetrisch aufgebaut sind. Der Wegeventilkolben 3 ist ein Hohlschieber. Im Ventilgehäuse 1 sind von der Längsbohrung 2 her verschiedene Ringkanäle eingestochen, nämlich im Symmetriemittelpunkt ein Tankanschluß-Ringkanal T, dem von der senkrechten Symmetrieachse Ss in Richtung auf die Stirnseite des Ventilgehäuses 1 weitere Ringkanäle folgen, nämlich nach links ein Arbeitsanschluß-Ringkanal A und nach rechts ein Arbeitsanschluß-Ringkanal B. Diese beiden Arbeitsanschluß-Ringkanäle A, B stehen in Verbindung mit den Lastanschlüssen des Wegeventils, die üblicherweise mit " A" und "B" bezeichnet werden.1, part of a valve housing is shown with the reference number 1, which has a longitudinal bore 2. With a horizontal axis of symmetry S w and a vertical axis of symmetry S s, it is indicated that the valve housing 1 and also a directional valve piston 3 which is displaceable in the longitudinal bore 2 are symmetrically constructed in two axes. The directional valve piston 3 is a hollow slide. In the valve housing 1 different annular channels are pierced from the longitudinal bore 2, namely a tank connection ring channel T in the center of symmetry, followed by further vertical channels from the vertical axis of symmetry S s towards the front side of the valve housing 1, namely to the left a working connection ring channel A and to the right is a working connection ring channel B. These two working connection ring channels A, B are connected to the load connections of the directional control valve, which are usually referred to as "A" and "B".
Nach rechts anschließend folgt auf den Arbeitsanschluß-Ringkanal B ein Pumpendruck- Ringkanal P, dann ein Load-Sensing-Ringkanal LS und schließlich ein Endraum- Ringkanal E. Die gleiche Aufeinanderfolge von Ringkanälen ist auch nach links vorhanden, in der Fig. 1 aber nicht dargestellt. Der Wegeventilkolben 3 weist seinerseits eine Axialbohrung 4 auf, in der ein Druckwaagekolben 5 gegen eine Druckwaagefeder 6 axial verschiebbar ist. Die Darstellung der Fig. 1 zeigt den Wegeventilkolben 3 in der Neutralstellung, bei der von den Arbeitsanschluß-Ringkanälen A und B weder eine Verbindung zum Tankanschluß- Ringkanal T noch zum Pumpendruck-Ringkanal P besteht. Der an die Lastanschlüssen des Wegeventils, die wie erwähnt mit "A" und "B" bezeichnet sind, angeschlossene hydraulische Verbraucher steht damit still.To the right, the working connection ring channel B is followed by a pump pressure ring channel P, then a load-sensing ring channel LS and finally an end space ring channel E. The same sequence of ring channels is also present to the left, but not in FIG. 1 shown. The directional control valve piston 3 in turn has an axial bore 4, in which a pressure compensating piston 5 can be axially displaced against a pressure compensating spring 6. The illustration in FIG. 1 shows the directional control valve piston 3 in the neutral position, in which there is neither a connection to the tank connection ring channel T nor to the pump pressure ring channel P from the working connection ring channels A and B. The hydraulic consumer connected to the load connections of the directional control valve, which are referred to as "A" and "B" as mentioned, is thus stationary.
Der Druckwaagekolben 5 ist ebenfalls ein Hohlschieber, umschließt also einen Innenraum 7, der gegen die senkrechte Symmetrieachse Ss offen ist, auf der anderen Seite aber eine geschlossene Stirnwand 8 aufweist.The pressure compensating piston 5 is also a hollow slide, that is, it encloses an interior space 7 that is open against the vertical axis of symmetry S s , but on the other side has a closed end wall 8.
Der Wegeventilkolben 3 ist stirnseitig ebenfalls verschlossen, beispielsweise mittels einer einschraubbaren Verschlußkappe 9. Zwischen der Verschlußkappe 9 des Wegeventilkolbens 3 und der Stirnwand 8 des Druckwaagekolbens 5 ist die schon erwähnte Druckwaagefeder 6 angeordnet.The directional valve piston 3 is also closed on the end face, for example by means of a screw-in closure cap 9. The already mentioned pressure balance spring 6 is arranged between the closure cap 9 of the directional valve piston 3 and the end wall 8 of the pressure compensating piston 5.
Auf der linken offenen Seite weist der Druckwaagekolben 5 Steuerrippen 10 auf. Diese bilden Fortsätze des zylindrischen Teils der Druckwaagekolbens 5. Um deren Form und Lage zu verdeutlichen, ist eine Schnittlinie II-II eingezeichnet, wobei der entsprechende Schnitt in der Fig. 2 dargestellt ist. In der Fig. 2 sind die Steuerrippen 10 geschnitten, während die dazwischen liegenden Stirnflächen des Druckwaagekolbens 5 in der Aufsicht gezeigt sind. Die ringabschschnittsförmigen Zwischenräume zwischen denThe pressure compensating piston has 5 control ribs 10 on the left open side. These form extensions of the cylindrical part of the pressure compensating piston 5. In order to clarify their shape and position, a section line II-II is drawn in, the corresponding section being shown in FIG. 2. 2, the control ribs 10 are cut, while the end faces of the pressure compensating piston 5 lying in between are shown in a top view. The annular section-shaped spaces between the
Steuerrippen 10 werden als Feinsteuerkerben bezeichnet und sind mit der Bezugszahl 11 versehen.Control ribs 10 are referred to as fine control notches and are provided with the reference number 11.
Auf die Bedeutung der Form der Stirnfläche 12 der Axialbohrung 4 mit einer anschließenden Querschnittserweiterung 13 in der Axialbohrung 4 wird später eingegangen werden.The importance of the shape of the end face 12 of the axial bore 4 with a subsequent cross-sectional expansion 13 in the axial bore 4 will be discussed later.
Für die Funktion des Wegeventils wesentliche Elemente sind zusätzlich in der Fig. 1 eingezeichnet. Mit der Bezugszahl 19 ist eine Steuerfeder bezeichnet, die von einem nicht dargestellten Antrieb her auf den Wegeventilkolben 3 einwirkt. Funktionswesentlich sind Tanksteuernuten 20, die in der Mantelfläche des Wegeventilkolbens 3 eingefräst sind und dazu dienen, bei entsprechender relativer Lage des Wegeventilkolbens 3 zumElements essential for the function of the directional control valve are additionally shown in FIG. 1. The reference number 19 designates a control spring which acts on the directional control valve piston 3 from a drive (not shown). Functionally essential are tank control grooves 20, which are milled into the lateral surface of the directional valve piston 3 and which, with a corresponding relative position of the directional valve piston 3, serve to
Ventilgehäuse 1 den Fluß des Hydraulikmediums vom Arbeitsanschluß-Ringkanal B bzw. Arbeitsanschluß-Ringkanal A zum Tankanschluß-Ringkanal T zu ermöglichen, was die beiden Arbeitsstellungen des Wegeventils charakterisiert. Wird beispielsweise der Wegeventilkolben 3 aus der in der Fig. 1 gezeigten Position nach rechts verschoben, so entsteht über die Tanksteuernuten 20 die Verbindung zwischen dem Arbeitsanschluß- Ringkanal B und dem Tankanschluß-Ringkanal T.Valve housing 1 to allow the flow of the hydraulic medium from the working connection ring channel B or working connection ring channel A to the tank connection ring channel T, which characterizes the two working positions of the directional control valve. If, for example, the directional valve piston 3 is shifted to the right from the position shown in FIG. 1, then the connection between the working connection ring channel B and the tank connection ring channel T is established via the tank control grooves 20.
Funktionswesentlich sind weiter ein erster Ventilkolben-Radialdurchbruch 21 und ein zweiter Ventilkolben-Radialdurchbruch 22, auf deren funktionelle Bedeutung noch eingegangen wird. Im zylindrischen Mantel des Wegeventilkolbens 3 sind außerdem Verbindungsbohrungen 23 angeordnet, durch die eine dauernde Verbindung zwischen dem Load-Sensing-Ringkanal LS und dem die Druckwaagefeder 6 umgebenden Raum, der als Druckwaagen-Federraum 24 bezeichnet ist, hergestellt ist. Damit diese Verbindung bei allen Stellungen des Druckwaagekolbens 5 innerhalb des Wegeventilkolben 3 besteht, ist beispielsweise der Innendurchmesser desA first valve piston radial breakthrough 21 and a second valve piston radial breakthrough 22 are also essential in terms of their function, the functional significance of which is still to be discussed. In the cylindrical casing of the directional control valve piston 3, connection bores 23 are also arranged, through which a permanent connection between the load-sensing ring channel LS and the space surrounding the pressure compensator spring 6, which is referred to as the pressure compensator spring chamber 24, is produced. So that this connection exists at all positions of the pressure compensating piston 5 within the directional control valve piston 3, the inside diameter of the valve is, for example
Wegeventilkolbens 3 im Bereich des Druckwaagen-Federraum 24 größer als der Außendurchmesser des Druckwaagekolbens 5. Es können aber auch andere Mittel, etwa Längsnuten, vorhanden sein, um diese dauernde Verbindung zwischen dem Load- Sensing-Ringkanal LS und dem Druckwaagen-Federraum 24 zu garantieren. Dadurch wirkt im Druckwaagen-Federraum 24 unter allen Umständen der im Load-Sensing- Ringkanal LS herrschende Druck, was im Zusammenwirken mit der Druckwaagefeder 6 erfindungsgemäß garantiert, daß der Druckwaagekolben 5 eine eindeutige Lage einnimmt, bei der der Druckwaagekolben 5 den Arbeitsanschluß-Ringkanal B sicher absperrt, womit jener Teil der Aufgabe gelöst wird, daß es in der Stellung "Neutral" nicht zu einer Bewegung des hydraulischen Verbrauchers kommen kann. Der Druckwaagen- Federraum 24 ist funktioneil ein Steuerdruckraum. Erfindungswesentlich ist, daß zwischen dem Load-Sensing-Ringkanal LS und dem Druckwaagen-Federraum 24 keine Steuerkante liegt, die den Druck im Druckwaagen-Federraum 24 in ungünstiger Weise beeinflussen könnte. Als erste Steuerkante des Druckwaagekolben 5 wirkt die Umfangslinie des Druckwaagekolbens 5 im Bereich der Feinsteuerkerben 10. DieseDirectional valve piston 3 in the area of the pressure compensator spring chamber 24 is larger than the outside diameter of the pressure compensator piston 5. However, other means, such as longitudinal grooves, can also be present in order to guarantee this permanent connection between the load-sensing ring channel LS and the pressure compensator spring chamber 24 , As a result, the pressure prevailing in the load-sensing ring channel LS acts in the pressure compensator spring chamber 24, which, in cooperation with the pressure compensator spring 6, guarantees according to the invention that the pressure compensator piston 5 assumes a clear position in which the pressure compensator piston 5 adopts the working connection annular duct B. shuts off safely, which solves that part of the task that in the "neutral" position there can be no movement of the hydraulic consumer. The pressure compensator spring chamber 24 is functionally a control pressure chamber. It is essential to the invention that there is no control edge between the load-sensing ring channel LS and the pressure compensator spring chamber 24, which could adversely affect the pressure in the pressure compensator spring chamber 24. The circumferential line of the pressure compensating piston 5 acts as the first control edge of the pressure compensating piston 5 in the area of the fine control notches 10
Steuerkante ist in den Fig. 1 und 2 mit der Bezugszahl 30 versehen. Erfindungswesentlich ist ein an sich aus dem Stand der Technik bekanntes Merkmal, nämlich, daß der Druckwaagekolben 5 in seinem zylindrischen Mantel mindestens einen Radialdurchbruch 31 aufweist. Vorteilhaft jedoch mehrere solcher Radialdurchbrüche 31 vorhanden, die gleichmäßig über den Umfang des Druckwaagekolbens 5 verteilt sind. Jeder der Radialdurchbrüche 31 hat die Gestalt eines länglichen Schlitzes.The control edge is provided with the reference number 30 in FIGS. 1 and 2. Essential to the invention is a feature known per se from the prior art, namely that the pressure compensating piston 5 has at least one radial opening 31 in its cylindrical casing. Advantageously, however, several such radial openings 31 are present, which are evenly distributed over the circumference of the pressure compensating piston 5. Each of the radial openings 31 has the shape of an elongated slot.
Als zweite Steuerkante des Druckwaagekolben 5 wirken die Radialdurchbrüche 31. Sie stehen in dauernder Verbindung mit dem Ventilkolben-Radialdurchbruch 22. Steigt der Druck in der Axialbohrung 4 des Wegeventilkolbens 3 und im Innenraum 7 des Druckwaagekolbens 5 so hoch, daß die durch diesen Druck entstehende, auf den Druckwaagekolben 5 wirkende Kraft größer wird als die Summe der Kraft der Druckwaagefeder 6 und der aus dem Druck im Druckwaagen-Federraum 24 auf den Druckwaagekolben 5 wirkenden Kraft, so bewegt sich der Druckwaagekolben 5 so weit nach rechts gegen die Druckwaagefeder 6, bis wieder Kraftgleichgewicht besteht. Bei genügend hohem Druck in der Axialbohrung 4 des Wegeventilkolbens 3 und im rnnenraum 7 des Druckwaagekolbens 5 bewegt sich der Druckwaagekolben 5 so weit nach rechts gegen die Druckwaagefeder 6, bis die Axialbohrung 4 desThe radial openings 31 act as the second control edge of the pressure compensating piston 5. They are in permanent connection with the valve piston radial opening 22. If the pressure in the axial bore 4 of the directional control valve piston 3 and in the interior 7 of the pressure compensating piston 5 increases so high that the pressure force acting on the pressure compensator piston 5 is greater than the sum of the force of the pressure compensator spring 6 and that resulting from the pressure in the pressure compensator spring chamber 24 Pressure compensator piston 5 acting force, the pressure compensator piston 5 moves so far to the right against the pressure compensator spring 6 until the force is balanced again. At a sufficiently high pressure in the axial bore 4 of the directional control valve piston 3 and in the inner space 7 of the pressure compensator piston 5, the pressure compensator piston 5 moves to the right against the pressure compensator spring 6 until the axial bore 4 of the
Wegeventilkolbens 3 und der Innenraum 7 des Druckwaagekolbens 5 mit dem Druckwaagen-Federraum 24 verbunden sind, was noch gezeigt werden wird.Directional valve piston 3 and the interior 7 of the pressure compensator piston 5 are connected to the pressure compensator spring chamber 24, which will be shown later.
In den Fig. 1 und 2 ist zudem noch ein Durchmesser dDw eingezeichnet, der den Außendurchmesser des Druckwaagekolbens 5 bezeichnet. Dieser Durchmesser dDw bestimmt die hydrostatische Kraftwirkung, die aufgrund des im Druckwaagen-1 and 2, a diameter d Dw is also shown, which denotes the outer diameter of the pressure compensating piston 5. This diameter d Dw determines the hydrostatic force effect, which is due to the
Federraum 24 herrschenden Druckes aufgrund der Fläche dDw ' π/4 entsteht, denn diese Fläche ist die wirksame Steuerdruckfläche. In der Fig. 2 ist zudem der Innendurchmesser des Druckwaagekolbens 5 eingezeichnet und mit dr bezeichnet. Inwieweit dieser Innendurchmesser di bedeutsam ist, wird noch erläutert werden.Spring chamber 24 prevailing pressure due to the area d Dw ' π / 4, because this area is the effective control pressure area. In Fig. 2, the inner diameter of the pressure compensating piston 5 is also shown and denoted by d r . The extent to which this inner diameter di is important will be explained later.
In der Fig. 3 ist eine Arbeitsstellung des Wegeventilkolbens 3 gezeigt. Durch einen bei solchen Wegeventilen vorhandenen Antrieb, der in allen Figuren nicht gezeigt ist, ist der Wegeventilkolben 3 innerhalb des Ventilgehäuses 1 nach links verschoben. Damit besteht Durchfluß vom Pumpendruck-Ringkanal P zum Arbeitsanschluß-Ringkanal B. Hydraulikmedium kann nun vom Pumpendruck-Ringkanal P durch den zweiten Ventilkolben-Radialdurchbruch 22 des Wegeventilkolbens 3 und durch den3 shows a working position of the directional valve piston 3. Due to a drive present in such directional control valves, which is not shown in all the figures, the directional control valve piston 3 is displaced to the left within the valve housing 1. This means that there is flow from the pump pressure ring channel P to the working connection ring channel B. Hydraulic medium can now flow from the pump pressure ring channel P through the second valve piston radial opening 22 of the directional control valve piston 3 and through the
Radialdurchbruch 31 des Druckwaagekolbens 5 in Innenraum 7 des Druckwaagekolbens 5 strömen und von dort weiter in die Axialbohrung 4 des Wegeventilkolbens 3 und weiter durch den ersten Ventilkolben-Radialdurchbruch 21 in den Arbeitsanschluß-Ringkanal B. Der mögliche Fluß des Hydraulikmediums ist durch drei punktierte Linien gekennzeichnet, woraus ersichtlich wird, daß der Fluß des Hydraulikmediums sich über den ganzen freien Querschnitt im Innenraum 7 des Druckwaagekolbens 5 und in der Axialbohrung 4 des Wegeventilkolbens 3 verteilt. Der Übersichtlichkeit wegen sind in diesem Schnittbild nur die vom unten gezeigten Teil des Pumpendruck-Ringkanals P ausgehenden Flußlinien gezeigt. Da es sich aber bei den im Ventilgehäuse 1 vorhandenen Kanälen immer um umlaufende Ringkanäle handelt, verteilt sich der Fluß desRadial breakthrough 31 of the pressure compensating piston 5 flow into the interior 7 of the pressure compensating piston 5 and from there further into the axial bore 4 of the directional control valve piston 3 and further through the first valve piston radial breakthrough 21 into the working connection annular duct B. The possible flow of the hydraulic medium is indicated by three dotted lines , from which it can be seen that the flow of the hydraulic medium is distributed over the entire free cross section in the interior 7 of the pressure compensating piston 5 and in the axial bore 4 of the directional control valve piston 3. For the sake of clarity, only the flow lines emanating from the part of the pump pressure ring channel P shown below are shown in this sectional view. However, since the channels in the valve housing 1 are always circumferential ring channels, the flow of the
Hydraulikmediums auf die ganzen Ringflächen. Hier ist nun bedeutungsvoll, daß der innere Durchmesser Oι des Druckwaagekolbens 5 relativ groß ist, was zur Folge hat, daß die Strömungsgeschwindigkeit im Innenraum 7 des Druckwaagekolbens 5 relativ klein ist. Das gilt auch für den Fluß in der Axialbohrung 4 des Wegeventilkolbens 3. Wegen der kleinen Strömungsgeschwindigkeit sind die hydrodynamischen Kräfte klein. Dies bewirkt in Übereinstimmung mit der gestellten Aufgabe, daß die Druckwaage unempfindlich gegen durch unterschiedliche Mengenströme verursachte unterschiedliche Strömungskräfte ist.Hydraulic medium on the entire ring surfaces. Here it is important that the inner diameter Oι of the pressure compensating piston 5 is relatively large, which means that the flow velocity in the interior 7 of the pressure compensating piston 5 is relatively small. This also applies to the flow in the axial bore 4 of the directional valve piston 3. Because of the low flow velocity, the hydrodynamic forces are small. In accordance with the task, this causes the pressure compensator to be insensitive against different flow forces caused by different flow rates.
Durch das Öffnen des zweiten Ventilkolben-Radialdurchbruch 22 des Wegeventilkolbens 3 zum Pumpendruck-Ringkanals P entsteht im Innenraum 7 des Druckwaagekolbens 5 ein Druck, der etwa dem Pumpendruck entspricht. Dieser Druck wirkt nun gegen den im Druckwaagen-Federraum 24 herrschenden Druck, der mit dem Druck im Load-Sensing-Ringkanal LS korreliert. Entsprechend wird der Druckwaagekolben 5 gegen die Druckwaagefeder 6 bewegt, so daß sich die in der Fig. 3 gezeigte Position des Druckwaagekolbens 5 innerhalb des Wegeventilkolbens 3 ergibt, wie dies zuvor schon angedeutet worden ist. Die tatsächliche Position desBy opening the second valve piston radial opening 22 of the directional valve piston 3 to the pump pressure ring channel P, a pressure is generated in the interior 7 of the pressure compensating piston 5, which corresponds approximately to the pump pressure. This pressure now acts against the pressure prevailing in the pressure compensator spring chamber 24, which pressure correlates with the pressure in the load-sensing ring channel LS. Accordingly, the pressure compensator piston 5 is moved against the pressure compensator spring 6, so that the position of the pressure compensator piston 5 shown in FIG. 3 results within the directional control valve piston 3, as has already been indicated. The actual position of the
Druckwaagekolbens 5 innerhalb des Wegeventilkolbens 3 regelt sich ein entsprechend der Differenz der Kraftwirkungen, die aus den Drücken im Pumpendruck-Ringkanal P und im Load-Sensing-Ringkanal LS entstehen.Pressure balance piston 5 within the directional control valve piston 3 adjusts itself in accordance with the difference in the force effects which arise from the pressures in the pump pressure ring channel P and in the load-sensing ring channel LS.
Im ersten Schritt öffnet der Druckwaagekolben 5 über seine Steuerrippen 10 die Verbindung zwischen dem Ventilkolben-Radialdurchbruch 21 und der Axialbohrung 4 des Wegeventilkolbens 3, so daß sich am Ventilkolben-Radialdurchbruch 21 ein bestimmter Abflußquerschnitt ergibt. Wenn der Druck im Arbeitsanschluß-Ringkanal B, entsprechend dem Druck am entsprechenden Lastanschluß des Verbrauchers, hoch ist und die resultierende Druckkraft am Druckwaagekolben 5 die Summe aus dem Druck im Druckwaagen-Federraum 24 und der Kraft der Druckwaagefeder 6 überwindet, dann staut sich der Druck im Innenraum 7 des Druckwaagekolbens 5 auf den Druck im Arbeitsanschluß-Ringkanal B an und bewegt den Druckwaagekolben 5 gegen die Druckwaagefeder 6 so weit nach rechts, wie dies in der Fig. 3 gezeigt ist. Dabei ist dann der Druckwaagen-Federraum 24 mit dem Innenraum 7 des Druckwaagekolbens 5 verbunden. Der Druck im Load-Sensing-Ringkanal LS folgt diesem Wert wegen der Verbindung vom Innenraum 7 des Druckwaagekolbens 5 über die Verbindungsbohrungen 23 zum Load-Sensing-Ringkanal LS. Die Bewegung des Verbrauchers erfolgt nun in bekannter Weise durch die Wirkung eines nicht dargestellten Pumpenreglers. Der Pumpenregler hebt den Pumpendruck genau so viel an, daß über den eingestellten Drosselquerschnitt des zweiten Ventilkolben-Radialdurchbruch 22 desIn the first step, the pressure compensating piston 5 opens the connection between the valve piston radial opening 21 and the axial bore 4 of the directional control valve piston 3 via its control ribs 10, so that a certain discharge cross-section results at the valve piston radial opening 21. If the pressure in the working connection ring channel B, corresponding to the pressure at the corresponding load connection of the consumer, is high and the resulting pressure force on the pressure compensator piston 5 overcomes the sum of the pressure in the pressure compensator spring chamber 24 and the force of the pressure compensator spring 6, then the pressure builds up in the interior 7 of the pressure compensator piston 5 to the pressure in the working connection ring channel B and moves the pressure compensator piston 5 against the pressure compensator spring 6 as far to the right as is shown in FIG. 3. The pressure compensator spring chamber 24 is then connected to the interior 7 of the pressure compensator piston 5. The pressure in the load-sensing ring channel LS follows this value because of the connection from the interior 7 of the pressure compensating piston 5 via the connecting bores 23 to the load-sensing ring channel LS. The movement of the consumer now takes place in a known manner through the action of a pump regulator, not shown. The pump regulator raises the pump pressure so much that the throttle cross section of the second valve piston radial opening 22 des
Wegeventilkolbens 3 wegen der bestimmten Durchflußmenge des Hydraulikmediums der Druckabfall genau so hoch ist wie die am Pumpenregler vorgegebene Differenz "Pumpendruck minus Steuerdruck".Directional valve piston 3 due to the determined flow rate of the hydraulic medium, the pressure drop is exactly as high as the difference "pump pressure minus control pressure" specified on the pump controller.
Ein zweiter Schritt der Druckwaagen-Regelung findet dann statt, wenn der Druck im Arbeitsanschluß-Ringkanal B, entsprechend dem Druck am entsprechenden Lastanschluß des Verbrauchers, kleiner als der Pumpendruck ist. Durch das abfließende Hydraulikmedium sinkt der Druck im Innenraum 7 des Druckwaagekolbens 5 so weit, daß sich der Druckwaagekolben 5 unter dem Einfluß der Druckwaagefeder 6 in Verbindung mit dem Druck im Druckwaagen-Federraum 24 so lange nach links bewegt, bis die Steuerrippen 10 den Abflußquerschnitt am Ventilkolben-Radialdurchbruch 21 so weit verringert haben, bis sich der jetzt wieder aufgestaute Druck im Innenraum 7 des Druckwaagekolbens 5 im Kraftgleichgewicht befindet mit den Kräften, die aus der Wirkung des Druckes im Druckwaagen-Federraum 24 und der Druckwaagefeder 6 resultieren.A second step of the pressure compensator control takes place when the pressure in the working connection ring channel B, corresponding to the pressure at the corresponding load connection of the consumer, is lower than the pump pressure. Through the draining Hydraulic medium drops the pressure in the interior 7 of the pressure compensator piston 5 so far that the pressure compensator piston 5 moves under the influence of the pressure compensator spring 6 in connection with the pressure in the pressure compensator spring chamber 24 until the control ribs 10 have the discharge cross-section at the valve piston radial breakthrough 21 have reduced until the pressure that has now accumulated again in the interior 7 of the pressure compensating piston 5 is in force equilibrium with the forces which result from the effect of the pressure in the pressure compensating spring chamber 24 and the pressure compensating spring 6.
Es wurde schon erwähnt, daß der Innendurchmesser di des Druckwaagekolbens 5 bedeutungsvoll ist. Der maximale Durchfluß des Hydraulikmediums durch dieIt has already been mentioned that the inside diameter di of the pressure compensating piston 5 is significant. The maximum flow of the hydraulic medium through the
Druckwaage ergibt sich dann, wenn durch die relative Lage des zweiten Ventilkolben- Radialdurchbruchs 22 des Wegeventilkolbens 3 zum Pumpendruck-Ringkanal P der größte wirksame Öffhungsquerschnitt für den Radialdurchbruch 22 gegeben ist. Ist der Innendurchmesser dj des Druckwaagekolbens 5 groß, ergibt sich dabei eine kleine axiale Strömungsgeschwindigkeit im Innenraum 7 des Druckwaagekolbens 5 mit entsprechend geringen Strahlkräften. Es hat sich als vorteilhaft erwiesen, wenn der Innendurchmesser d] so bemessen ist, daß die Fläche dϊ ' π/4 etwa das Drei- bis Fünffache der Fläche des Radialdurchbruchs 22 beträgt.Pressure compensator results when the largest effective opening cross-section for the radial opening 22 is given by the relative position of the second valve piston radial opening 22 of the directional valve piston 3 to the pump pressure ring channel P. If the inside diameter dj of the pressure compensating piston 5 is large, this results in a small axial flow velocity in the interior 7 of the pressure compensating piston 5 with correspondingly low jet forces. It has proven to be advantageous if the inner diameter d] is dimensioned such that the area d ϊ ' π / 4 is approximately three to five times the area of the radial opening 22.
Erfindungsgemäß steht der Druckwaagen-Federraum 24 grundsätzlich und immerwährend mit dem Load-Sensing-Ringkanal LS in Verbindung. Der Druck im Innenraum 7 des Druckwaagekolbens 5 kann je nach Arbeitsstellung des Wegeventilkolbens 3 unterschiedlich sein. Bei der in der Fig. 1 gezeigten Neutralstellung ist er unbestimmt. Um zu erreichen, daß auch in dieser Stellung der Innenraum 7 des Druckwaagekolbens 5 einen definierten Druck aufweist, ist es vorteilhaft, eine Drackentlastungsbohrung 40 vorzusehen, durch die in der Neutralstellung des Wegeventilkolbens 3 die Axialbohrung 4 des Wegeventilkolbens 3 und somit auch der Innenraum 7 des Druckwaagekolbens 5 mit dem Tankanschluß-Ringkanal T verbunden ist. Durch die Druckentlastungsbohrung 40 ist der Innenraum 7 des Druckwaagekolbens 5 also mit dem Tankanschluß-Ringkanal T verbindbar, aber nur in der Neutralstellung verbunden. Weil der Druck im Tankanschluß- Ringkanal T beim Betrieb des Verbrauchers grundsätzlich kleiner ist als der Druck im Load-Sensing-Ringkanal LS, wird also erreicht, daß Druckwaagekolben 5 nicht allein aufgrund der Wirkung der Druckwaagefeder 6 die gewünschte eindeutige Lage einnimmt, sondern durch die Druckdifferenz zwischen Load-Sensing-Ringkanal LS und Tankanschluß-Ringkanal T noch unterstützt wird. Probleme durch Leckage-Druckverluste können so nicht entstehen. Eine alternative Möglichkeit, in der Neutralstellung die gewünschte eindeutige Lage des Druckwaagekolbens 5 durch eindeutige Festlegung des Druckes im Innenraum 7 des Druckwaagekolbens 5 zu erreichen, besteht darin, in der Neutralstellung den Innenraum 7 mit dem Load-Sensing-Ringkanal LS zu verbinden. Dann bestimmt die Druckwaagefeder 6 allein die eindeutige Lage des Druckwaagekolbens 5 in derAccording to the invention, the pressure compensator spring chamber 24 is fundamentally and continuously connected to the load-sensing ring channel LS. The pressure in the interior 7 of the pressure compensating piston 5 can vary depending on the working position of the directional valve piston 3. In the neutral position shown in FIG. 1, it is indefinite. In order to ensure that the interior 7 of the pressure compensating piston 5 also has a defined pressure in this position, it is advantageous to provide a pressure relief bore 40 through which, in the neutral position of the directional control valve piston 3, the axial bore 4 of the directional control valve piston 3 and thus also the interior 7 of the Pressure compensating piston 5 is connected to the tank connection ring channel T. Through the pressure relief bore 40, the interior 7 of the pressure compensating piston 5 can thus be connected to the tank connection ring channel T, but is only connected in the neutral position. Because the pressure in the tank connection ring channel T during operation of the consumer is generally lower than the pressure in the load-sensing ring channel LS, it is achieved that pressure compensating piston 5 assumes the desired unambiguous position not only because of the effect of the pressure compensating spring 6, but also because of the Pressure difference between the load-sensing ring channel LS and the tank connection ring channel T is still supported. Problems caused by leakage pressure losses cannot arise in this way. An alternative way of achieving the desired unique position of the pressure compensating piston 5 in the neutral position by clearly defining the pressure in the interior 7 of the pressure compensating piston 5 is to connect the interior 7 to the load-sensing ring channel LS in the neutral position. Then the pressure compensator spring 6 alone determines the unique position of the pressure compensator piston 5 in the
Neutralstellung. Probleme durch Leckage-Druckverluste können auch so nicht entstehen. Die Verbindung des Innenraums 7 mit dem Load-Sensing-Ringkanal LS wird erfindungsgemäß dadurch erreicht, daß dem Ventilkolben-Radialdurchbruch 22 eine andere Gestalt gegeben wird. In den Fig. 1 und 3 ist durch gestrichelte Linien eine Ringnut 41 gezeigt, die unmittelbar an den Ventilkolben-Radialdurchbruch 22 anschließt. Aus der Fig. 1 ist erkennbar, daß durch diese an den Ventilkolben-Radialdurchbruch 22 anschließende Ringnut 41 eine Verbindung vom Innenraum 7 zum Load-Sensing- Ringkanal LS besteht, während der der Fig. 3 erkennbar ist, daß diese Ringnut 41 in der Arbeitsstellung des Wegeventilkolbens 3 wirkungslos ist. Vorteilhaft ist diese erfindungsgemäße Lösung mit der Ringnut 41 insbesondere hinsichtlich der Herstellungskosten.Neutral. Problems caused by leakage pressure losses cannot arise in this way either. The connection of the interior 7 with the load-sensing ring channel LS is achieved according to the invention in that the valve piston radial opening 22 is given a different shape. 1 and 3, an annular groove 41 is shown by dashed lines, which connects directly to the valve piston radial opening 22. From Fig. 1 it can be seen that through this to the valve piston radial opening 22 annular groove 41 there is a connection from the interior 7 to the load-sensing ring channel LS, during which Fig. 3 can be seen that this annular groove 41 in the working position of the directional valve piston 3 is ineffective. This solution according to the invention with the annular groove 41 is advantageous in particular with regard to the production costs.
In der Fig. 4 ist eine besondere Form der Stirnfläche 12 mit der Querschnittserweiterung 13 der Axialbohrung 4 im Wegeventilkolben 3 gezeigt. Der zentrische Teil der Stirnfläche 12 hat die Form eines sehr flachen Kegels 50 mit einem Spitzenwinkel von 150 bis 170 Grad. An den kegeligen Teil schließt eine zur4 shows a special shape of the end face 12 with the cross-sectional widening 13 of the axial bore 4 in the directional control valve piston 3. The central part of the end face 12 has the shape of a very flat cone 50 with a tip angle of 150 to 170 degrees. One closes to the conical part
Symmetrieachse Ss parallele Ringfläche 51 an, die dann in eine Rotationsellipsoid- Fläche 52 übergeht, die die Querschnittserweiterung 13 umgibt. Diese besondere Form hat vorteilhaften Einfluß auf die Strömung in der Axialbohrung 4 und stellt Mittel zur Umlenkung der Strömung dar. Bekanntermaßen erzeugt ein ein- bzw. ausströmender Strahl eine unerwünschte resultierende axiale Kraftkomponente, wenn die Ein- undAxis of symmetry S s parallel ring surface 51, which then merges into an ellipsoidal surface 52 which surrounds the cross-sectional widening 13. This particular shape has an advantageous influence on the flow in the axial bore 4 and represents means for deflecting the flow. As is known, an inflowing or outflowing jet generates an undesirable resulting axial force component when the inflow and outflow
Ausstrittsrichtungen verschiedenen sind. Wegen der je nach Öffnungsquerschnitten an der Druckwaage und am Wegeventilkolben 3 unterschiedlich großen Mengenströme ist der ein- bzw. ausströmender Strahl unterschiedlich stark. Durch die dargestellte und zuvor beschriebene Form wird eine Minimierung der unerwünschten Kraftkomponente erreicht.Exit directions are different. Because of the different flow rates depending on the opening cross sections on the pressure compensator and on the directional valve piston 3, the incoming and outgoing jet is of different strengths. The illustrated and previously described shape minimizes the undesired force component.
In der Fig. 5 ist eine Ausfuhrungsvariante für jenes Ende des Druckwaagekolbens 5 gezeigt, an dem sich die Steuerkante 30 befindet. Hier sind keine Steuerrippen 10 (Fig. 2) und Feinsteuerkerben 11 vorhanden. Stattdessen ist das das Ende des Druckwaagekolbens 5 kegelig angefast. Von der Steuerkante 30 her nimmt also der Außendurchmesser des Druckwaagekolbens 5 stetig ab. Es entsteht also ein Steuerspalt, der bei zunehmender Verschiebung des Druckwaagekolbens 5 aus der Neutralstellung immer größer wird. Alternative Ausgestaltungen sind in den Fig. 6 a) bis 6 c) gezeigt. In diesen Figuren ist die 360°- Abwicklung der Mantelfläche des Druckwaagekolbens 5 im Bereich der Feinsteuerkerben 11 gezeigt. Dabei entspricht die Fig. 6 a) der Ausfuhrungsform nach den Fig. 1 bis 3, während die Fig. 6 b) und 6 c) alternative Ausfuhrungsformen zeigen. Die Fig. 6 b) zeigt dreieckförmige Zwischenräume und die Fig. 6 c) kreissegmentformige Zwischenräume. Die Ausfuhrungsformen nach den Fig. 5 und 6 a) bis 6 c) zeigen also Mittel an der Steuerkante 30 des Druckwaagekolbens 5, mit denen sich die Abhängigkeit des wirksamen Öffhungsquerschnitts beim Verschieben des Druckwaagekolbens 5 in vorteilhafter Weise beeinflussen läßt. Um besondere Öffhungs-Charakteristika zu erreichen, lassen sich die verschiedenen Möglichkeiten auch kombinieren.5 shows an embodiment variant for that end of the pressure compensating piston 5 at which the control edge 30 is located. There are no control ribs 10 (FIG. 2) and fine control notches 11 here. Instead, the end of the pressure compensating piston 5 is chamfered. From the control edge 30, the outer diameter of the pressure compensating piston 5 is steadily decreasing. A control gap thus arises, which becomes larger and larger with increasing displacement of the pressure compensating piston 5 from the neutral position. Alternative configurations are shown in FIGS. 6 a) to 6 c). These figures show the 360 ° development of the outer surface of the pressure compensating piston 5 in the area of the fine control notches 11. 6 a) corresponds to the embodiment according to FIGS. 1 to 3, while FIGS. 6 b) and 6 c) show alternative embodiments. Fig. 6 b) shows triangular spaces and Fig. 6 c) circular segment-shaped spaces. 5 and 6 a) to 6 c) show means on the control edge 30 of the pressure compensating piston 5, with which the dependence of the effective opening cross section when moving the pressure compensating piston 5 can be influenced in an advantageous manner. In order to achieve special opening characteristics, the various options can also be combined.
In den Fig. 1 und 3 ist jeweils nur die eine Hälfte des Ventilgehäuses 1 und des Wegeventilkolbens 3 gezeigt. Aus der Symmetrie hinsichtlich der senkrechten Symmetrieachse Ss ergibt sich, daß auch in der nicht dargestelten zweiten Hälfte des Wegeventilkolbens 3 ein Druckwaagekolben 5 genau gleicher Bauart enthalten ist. Daraus folgt, daß beim hydraulischen Verbraucher mit zwei Arbeitsanschlüssen j edem der Arbeitsanschlüsse eine individuelle Druckwaage zugeordnet ist. 1 and 3, only one half of the valve housing 1 and the directional valve piston 3 is shown. From the symmetry with respect to the vertical axis of symmetry S s it follows that a pressure compensating piston 5 of exactly the same type is also contained in the second half of the directional control valve piston 3, which is not shown. It follows that in the hydraulic consumer with two work connections, an individual pressure compensator is assigned to each of the work connections.

Claims

Patentansprüche claims
1. Wegeventil mit innenliegender Druckwaage, dessen Ventilgehäuse (1) eine Längsbohrung (2) aufweist, in die Ringkanäle (A, T, B, P, LS, E) eingestochen sind, bei dem in dieser Längsbohrung (2) ein Wegeventilkolben (3) axial verschiebbar ist, wobei dieser Wegeventilkolben (3) als mit einem ersten und einem zweiten Ventilkolben- Radialdurchbruch (21, 22) ausgestatteter Hohlschieber ausgebildet ist und eine Axialbohrung (4) aufweist, in der ein mit einer Steuerkante (30) ausgestatteter Druckwaagekolben (5) gegen eine Druckwaagefeder (6) axial verschiebbar ist, wobei der Druckwaagekolben (5) als Hohlschieber mit einem einen Innendurchmesser D aufweisenden Innenraum (7) ausgebildet ist und wenigstens einen Radialdurchbruch (31) aufweist, der so angeordnet ist, daß er dauernd mit dem zweiten Ventilkolben- Radialdurchbruch (22) in Verbindung steht, und außerdem Mittel vorhanden sind, durch die ein Druckwaagen-Federraum (24) dauernd mit dem Load-Sensing-Ringkanal (LS) verbunden ist, dadurch gekennzeichnet,1. Directional control valve with internal pressure compensator, the valve housing (1) of which has a longitudinal bore (2) into which ring channels (A, T, B, P, LS, E) are inserted, in which a directional control valve piston (3 ) is axially displaceable, whereby this directional valve piston (3) is designed as a hollow slide valve equipped with a first and a second valve piston radial opening (21, 22) and has an axial bore (4) in which a pressure compensating piston equipped with a control edge (30) 5) against a pressure compensator spring (6) is axially displaceable, the pressure compensator piston (5) being designed as a hollow slide with an inner diameter D having an interior (7) and having at least one radial opening (31) which is arranged so that it is always with the second valve piston radial breakthrough (22) is connected, and also means are available through which a pressure compensator spring chamber (24) is permanently connected to the load-sensing ring channel (LS), dad characterized by
- daß der Radialdurchbruch (31) des Druckwaagekolbens (5) so angeordnet ist, daß durch diesen Radialdurchbruch (31) und den zweiten Ventilkolben-Radialdurchbruch (22) eine Verbindung vom Innenraum (7) zum Pumpendruck-Ringkanal (P) aufsteuerbar ist,- That the radial opening (31) of the pressure compensating piston (5) is arranged so that through this radial opening (31) and the second valve piston radial opening (22) a connection from the interior (7) to the pump pressure ring channel (P) can be controlled,
- daß der zweite Ventilkolben-Radialdurchbruch (22) eine Steuerkante darstellt, über die eine Verbindung vom Innenraum (7) zum Load-Sensing-Ringkanal (LS) aufsteuerbar ist, und- That the second valve piston radial opening (22) represents a control edge, via which a connection from the interior (7) to the load-sensing ring channel (LS) can be opened, and
- daß unmittelbar an den zweiten Ventilkolben-Radialdurchbruch (22) eine Ringnut (41) anschließt, die in der Neutralstellung eine Verbindung vom Innenraum (7) zum Load- Sensing-Ringkanal (LS) herstellt- That an annular groove (41) connects directly to the second valve piston radial opening (22), which in the neutral position creates a connection from the interior (7) to the load-sensing annular channel (LS)
2. Wegeventil nach Anspruch 1 , dadurch gekennzeichnet, daß der zweite Ventilkolben- Radialdurchbruch (22) am Ende des Druckwaagekolbens (5) angeordnet ist.2. Directional control valve according to claim 1, characterized in that the second valve piston radial opening (22) is arranged at the end of the pressure compensating piston (5).
3. Wegeventil nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß die Steuerkante (30) des Druckwaagekolbens (5) an jenem stirnseitigen Ende des Druckwaagekolbens (5) angeordnet ist, das dem stirnseitigen Ende des Druckwaagekolbens (5) gegenüber liegt, an dem die Druckwaagefeder (6) angreift und der Druck im Druckwaagen-Federraum (24) wirksam ist.3. Directional control valve according to claim 1 or 2, characterized in that the control edge (30) of the pressure compensating piston (5) is arranged on that end of the pressure compensating piston (5) which is opposite the end of the pressure compensating piston (5), on which the Pressure compensator spring (6) attacks and the pressure in the pressure compensator spring chamber (24) is effective.
4. Wegeventil nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, daß im Wegeventilkolben (3) eine Druckentlastungsbohrung (40) angeordnet ist, durch die die Axialbohrung (4) des Wegeventilkolbens (3) und somit der Innenraum (7) des Druckwaagekolbens (5) mit dem Tankanschluß-Ringkanal (T) verbindbar ist, aber nur in der Neutralstellung des Wegeventils verbunden ist. 4. Directional control valve according to one of claims 1 to 3, characterized in that a pressure relief bore (40) is arranged in the directional control valve piston (3) through which the axial bore (4) of the directional control valve piston (3) and thus the interior (7) of the pressure compensating piston ( 5) can be connected to the tank connection ring channel (T), but is only connected in the neutral position of the directional valve.
5. Wegeventil nach einem der Ansprüche 3 bis 4, dadurch gekennzeichnet, daß im Bereich der Stirnfläche (12) der Axialbohrung (4) des Wegeventilkolbens (3) Mittel (13, 50, 51, 52) zur Umlenkung der Strömung angeordnet sind.5. Directional control valve according to one of claims 3 to 4, characterized in that in the region of the end face (12) of the axial bore (4) of the directional control valve piston (3) means (13, 50, 51, 52) are arranged for deflecting the flow.
6. Wegeventil nach Anspruch 5, dadurch gekennzeichnet, daß die Mittel (13, 50, 51, 52) zur Umlenkung der Strömung gebildet werden von einem sehr flachen Kegel (50), der den zentrische Teil der Stirnfläche (12) bildet, einer daran anschließenden Ringfläche (51), die parallel zu einer Symmetrieachse Ss liegt und übergeht in eine Rotationsellipsoid- Fläche (52), die eine Querschnittserweiterung (13) umgibt.6. Directional control valve according to claim 5, characterized in that the means (13, 50, 51, 52) for deflecting the flow are formed by a very flat cone (50) which forms the central part of the end face (12), one thereon adjoining ring surface (51), which is parallel to an axis of symmetry S s and merges into an ellipsoidal surface (52) surrounding a cross-sectional widening (13).
7. Wegeventil nach einem der Ansprüche 3 bis 6, dadurch gekennzeichnet, daß der Innendurchmesser O\ des Druckwaagekolben (5) so bemessen ist, daß die Fläche ά{ etwa das Drei- bis Fünffache der Fläche des Radialdurchbruchs 22 beträgt.7. Directional control valve according to one of claims 3 to 6, characterized in that the inner diameter O \ of the pressure compensating piston (5) is dimensioned such that the area ά {is approximately three to five times the area of the radial opening 22.
8. Wegeventil nach einem der Ansprüche 3 bis 7, dadurch gekennzeichnet, daß die Steuerkante (30) am Drackwaagekolben (5) durch besondere Mittel so gestaltet ist, daß die Abhängigkeit des wirksamen Öffnungsquerschnitts beim Verschieben des Druckwaagekolbens (5) beeinflußbar ist. 8. Directional control valve according to one of claims 3 to 7, characterized in that the control edge (30) on the Drackwaagekolben (5) is designed by special means so that the dependence of the effective opening cross section when moving the pressure compensating piston (5) can be influenced.
EP02727817A 2001-04-17 2002-03-13 Directional control valve comprising an internal pressure regulator Expired - Lifetime EP1381779B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
CH6992001 2001-04-17
CH6992001 2001-04-17
PCT/IB2002/000759 WO2002088550A1 (en) 2001-04-17 2002-03-13 Directional control valve comprising an internal pressure regulator

Publications (2)

Publication Number Publication Date
EP1381779A1 true EP1381779A1 (en) 2004-01-21
EP1381779B1 EP1381779B1 (en) 2006-05-17

Family

ID=4529886

Family Applications (1)

Application Number Title Priority Date Filing Date
EP02727817A Expired - Lifetime EP1381779B1 (en) 2001-04-17 2002-03-13 Directional control valve comprising an internal pressure regulator

Country Status (5)

Country Link
US (1) US6860291B2 (en)
EP (1) EP1381779B1 (en)
AT (1) ATE326636T1 (en)
DE (1) DE50206817D1 (en)
WO (1) WO2002088550A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102018001303A1 (en) * 2018-02-20 2019-08-22 Hydac Fluidtechnik Gmbh valve device

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102007048400A1 (en) * 2007-06-06 2008-12-11 Zf Friedrichshafen Ag Switching device for motor vehicle gearbox
DE102007026421A1 (en) * 2007-06-06 2008-12-11 Zf Friedrichshafen Ag Servo assistance unit
KR101546979B1 (en) * 2007-07-18 2015-08-24 섀플러 테크놀로지스 아게 운트 코. 카게 Valve part for a control valve for control of pressure medium flows
DE102007054134A1 (en) 2007-11-14 2009-05-20 Hydac Filtertechnik Gmbh Hydraulic valve device
US20140165767A1 (en) * 2012-12-19 2014-06-19 Deere And Company Manual synchronized gear shift assist
DE102019214685A1 (en) * 2019-09-25 2021-03-25 Zf Friedrichshafen Ag Housing for a valve

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4719753A (en) * 1985-02-22 1988-01-19 Linde Aktiengesellschaft Slide valve for load sensing control in a hydraulic system
WO1993021395A1 (en) * 1992-04-20 1993-10-28 Hitachi Construction Machinery Co., Ltd. Hydraulic circuit device for construction machines
DE19836564B4 (en) 1998-08-12 2005-12-29 Bosch Rexroth Aktiengesellschaft valve assembly
DE19855187A1 (en) * 1998-11-30 2000-05-31 Mannesmann Rexroth Ag Method and control arrangement for controlling a hydraulic consumer

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO02088550A1 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102018001303A1 (en) * 2018-02-20 2019-08-22 Hydac Fluidtechnik Gmbh valve device

Also Published As

Publication number Publication date
ATE326636T1 (en) 2006-06-15
WO2002088550A1 (en) 2002-11-07
DE50206817D1 (en) 2006-06-22
US6860291B2 (en) 2005-03-01
EP1381779B1 (en) 2006-05-17
US20040094210A1 (en) 2004-05-20

Similar Documents

Publication Publication Date Title
DE1601729C3 (en) Hydraulic control valve device working with pilot control
DE3323363A1 (en) PRE-CONTROLLED PRESSURE REDUCING VALVE
DE2949231C2 (en) Pressure medium valve, in particular pressure reducing valve
EP0902194A1 (en) Load-holding valve
DE4004931C2 (en) Pilot operated pressure cut-off valve
EP1381779B1 (en) Directional control valve comprising an internal pressure regulator
EP3526474B1 (en) Discharge pressure compensating valve and lifting-lowering device having a pressure compensating valve of this type
EP1984629A1 (en) Hydraulic control arrangement with regeneration and lowering brake valve
DE2523937A1 (en) HYDRAULIC CONTROL DEVICE
EP0943057A1 (en) Distributing valve for load-independent control of a hydraulic consumer with regards to direction and speed
EP1729014B1 (en) Control block and section of a control block
DE2316504C2 (en) Hydraulic flow control valve
EP2337980B1 (en) Control valve
DE10156500C5 (en) Pressure reducing valve
DE3840328A1 (en) Pilot-controlled directional control valve
EP1452744B1 (en) Hydraulic control device
EP1061268B1 (en) Rodside damping in single-acting cylinders
DE3622925C2 (en) Combined changeover and pressure relief valve
DE2215450C3 (en) Free jet servo valve
DE3844071A1 (en) DIRECTION VALVE FOR CONTROLLING A HYDRAULIC CYLINDER
EP0624732A1 (en) Hydraulic control device
DE4122317C2 (en) HYDRAULIC DIVIDER VALVE
EP0376023B1 (en) Electrohydraulic proportional valve
DE3839952C1 (en) Hydraulic spool valve
WO2004101263A1 (en) Drive for a punch or forming machine

Legal Events

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

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20030902

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

AX Request for extension of the european patent

Extension state: AL LT LV MK RO SI

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

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

Ref country code: IE

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

Effective date: 20060517

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20060517

Ref country code: FI

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

Effective date: 20060517

Ref country code: NL

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

Effective date: 20060517

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

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

Effective date: 20060517

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

Free format text: LANGUAGE OF EP DOCUMENT: GERMAN

REF Corresponds to:

Ref document number: 50206817

Country of ref document: DE

Date of ref document: 20060622

Kind code of ref document: P

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

Ref country code: SE

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

Effective date: 20060817

Ref country code: DK

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

Effective date: 20060817

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

Ref country code: ES

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

Effective date: 20060828

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

Ref country code: PT

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

Effective date: 20061017

ET Fr: translation filed
NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
REG Reference to a national code

Ref country code: IE

Ref legal event code: FD4D

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

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

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

26N No opposition filed

Effective date: 20070220

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

BERE Be: lapsed

Owner name: BUCHER HYDRAULICS G.M.B.H.

Effective date: 20070331

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

Ref country code: BE

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

Effective date: 20070331

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

Ref country code: MC

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

Effective date: 20070331

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

Ref country code: LI

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

Effective date: 20070331

Ref country code: CH

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

Effective date: 20070331

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

Ref country code: GR

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

Effective date: 20060818

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

Ref country code: AT

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

Effective date: 20070313

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

Ref country code: CY

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

Effective date: 20060517

Ref country code: LU

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

Effective date: 20070313

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

Ref country code: TR

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

Effective date: 20060517

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 15

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 16

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 17

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

Ref country code: FR

Payment date: 20210323

Year of fee payment: 20

Ref country code: IT

Payment date: 20210329

Year of fee payment: 20

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

Ref country code: DE

Payment date: 20210319

Year of fee payment: 20

Ref country code: GB

Payment date: 20210324

Year of fee payment: 20

REG Reference to a national code

Ref country code: DE

Ref legal event code: R071

Ref document number: 50206817

Country of ref document: DE

REG Reference to a national code

Ref country code: GB

Ref legal event code: PE20

Expiry date: 20220312

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

Ref country code: GB

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20220312