EP1499807A1 - Ensemble distributeur ls - Google Patents

Ensemble distributeur ls

Info

Publication number
EP1499807A1
EP1499807A1 EP03704291A EP03704291A EP1499807A1 EP 1499807 A1 EP1499807 A1 EP 1499807A1 EP 03704291 A EP03704291 A EP 03704291A EP 03704291 A EP03704291 A EP 03704291A EP 1499807 A1 EP1499807 A1 EP 1499807A1
Authority
EP
European Patent Office
Prior art keywords
pressure
valve
valve arrangement
proportional valve
arrangement according
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.)
Withdrawn
Application number
EP03704291A
Other languages
German (de)
English (en)
Inventor
Gottfried Olbrich
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.)
Bosch Rexroth AG
Original Assignee
Bosch Rexroth AG
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
Priority claimed from DE10245836A external-priority patent/DE10245836B4/de
Application filed by Bosch Rexroth AG filed Critical Bosch Rexroth AG
Publication of EP1499807A1 publication Critical patent/EP1499807A1/fr
Withdrawn legal-status Critical Current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

Definitions

  • the invention relates to an LS directional control valve arrangement according to the preamble of patent claim 1.
  • Directional valve arrangements of this type are used for the load pressure-independent control of consumers, for example of lift, tilt or side displacement cylinders of a forklift truck.
  • DE 36 03 811 C2 shows an LS directional control valve arrangement in which a slide valve of a proportional valve is guided in a common valve housing.
  • This proportional valve forms a direction and speed part of the directional control valve arrangement, the pressure medium speed being set via a measuring orifice.
  • the proportional valve is assigned a pressure compensator, via which the pressure drop across the orifice plate and thus the volume flow to the consumer is kept constant.
  • a check valve is arranged in the area between a pressure compensating piston and the slide of the proportional valve, which is formed downstream of the measuring orifice and enables a pressure medium flow to the consumer and blocks it in the opposite direction.
  • Proportional valve and the check valve are formed. Do you now want in such a, relatively compact
  • Integrate a pressure compensator into the housing an additional The functional axis is provided for the pressure compensator and the valve housing can be enlarged accordingly. Omitting the check valve and installing the pressure compensator in the functional axis of the check valve is only possible with considerable effort, since the pressure compensator upstream of the metering orifice would require an extremely complex channel arrangement and a correspondingly complex conversion of the valve housing. In contrast, the object of the invention is to create a LS directional valve arrangement which is of compact design with minimal expenditure on device technology.
  • a pressure compensator is integrated into the valve arrangement in such a way that a control edge determining the throttle cross section of the pressure compensator is arranged in the flow path between the measuring orifice and a directional part of the proportional valve. That is, this control edge is located downstream of the metering orifice and upstream of the directional part of the proportional valve.
  • the pressure medium therefore first flows from the measuring orifice of the proportional valve to the control edge of the pressure compensator and then back again to the directional part of the proportional valve.
  • the valve housing can be made considerably more compact than in the known solution.
  • the pressure compensator piston is advantageously designed as a hollow piston, the inner bore opening on the one hand in an end face forming the control edge and on the other hand in a radial bore. This is arranged downstream of the orifice of the proportional valve. The clear width of this radial bore forms an orifice that limits the maximum pressure medium flow.
  • Fine control notches can be formed on a slide of the proportional valve on the ring collar forming the measuring orifice.
  • lockable shut-off valves are advantageously provided downstream of the proportional valve.
  • a pocket which forms an annular gap is provided on the outer circumference of the pressure compensator piston and opens into a chamber via which the directional part of the proportional valve is connected to the throttle cross section of the pressure compensator determined by the control edge.
  • Opening the check valve can be provided with fine control notches on the control edges that open or close the connection between the consumer connection to the tank.
  • Figure 1 shows an embodiment of a LS directional control valve arrangement with a proportional valve and individual pressure compensator
  • FIG. 2 shows a circuit symbol of the valve arrangement from FIG. 1;
  • Figure 3 shows an embodiment of a LS directional control valve arrangement with a proportional valve, pressure compensator and two unlockable check valves
  • FIG. 4 shows a circuit diagram of a control block containing the valve arrangement according to FIG.
  • FIG. 5 shows a pressure control curve for a directional valve arrangement according to FIG. 3 in comparison to a variant in which the connection to the tank is blocked in the basic position of the proportional valve.
  • FIG. 1 shows the structure of a first embodiment of an LS directional valve arrangement 1.
  • the directional valve arrangement 1 has a valve housing in which two working connections A, B and a pressure connection P, a tank connection T and an LS connection (see FIG. 2) are formed are.
  • the valve housing 2 there is a continuously adjustable valve, in the following called proportional valve 4 and one Individual pressure compensator 6 added.
  • a slide 8 of the proportional valve is guided in a valve bore 10, in which chambers 12, 14, 16, 18, 20, 22 and 24 which are radially expanded in the order from left to right are formed. These chambers 12 to 24 are spaced apart from one another by annular webs of the valve housing 2.
  • annular collars 26, 28, 30, 34, 36 and 38 are formed by annular grooves in the chambers, the annular collars 26 and 38 forming end portions of the valve slide 8 protruding from the valve housing 2.
  • Fine control notches 40 are formed on the facing shoulder shoulders of the ring collars 26, 28, 30 and on the two ring shoulders of the collar 36.
  • the two chambers 14 and 18 are connected to the working connections B and A via working channels 42, 44.
  • the two chambers 12 and 20 are connected to the tank port T via tank channels, not shown, and the chamber 24 is connected to the pressure port P via a pressure channel 46.
  • the valve spool 8 is biased by a spring 48 into its illustrated basic position, in which a spring plate 50 which is displaceably guided on the valve spool 4 is supported on the left end face of the housing 2 and a spring plate 52 which is also displaceable on the end section of the valve spool 8 is supported on a closure cap 54 , When the valve slide 8 is axially displaced to the left (FIG.
  • a pressure compensator bore 58 is formed in the valve housing 2 parallel to the valve bore 10.
  • a pressure compensator piston 60 is axially displaceably guided, which is prestressed against a contact shoulder of the valve housing 2 by means of a control spring 62 with a stop projection 64.
  • the control spring 62 is in turn supported on a support sleeve 66 sealingly inserted in the pressure compensator bore 58.
  • the pressure compensator piston 60 is designed as a hollow piston and has an inner bore 68 which, on the one hand, opens into the end face of the pressure compensator piston 60 on the left in FIG. 1 and on the other hand into a radial bore 70.
  • a regulating edge 72 is formed on the left end face of the pressure compensator piston 60.
  • a circumferential pocket 74 is formed, which is connected via an axial groove 76 to a channel 78, which in the
  • Chamber 16 opens.
  • the control edge 72 is axially spaced from the adjacent peripheral edge of the valve housing, so that the connection between the channel 78 and the inner bore 68 is opened.
  • the radial bore 70 opens into a connecting channel 80, which in turn merges into the chamber 22.
  • the annular collars 26, 28, 30 in cooperation with the adjacent radial webs of the housing 2 form a directional part of the proportional valve 4, while the annular collar 36 in cooperation with the adjacent web and the chambers 22, 24 form a measuring orifice D1 ( Figure 4) forms for setting the pressure medium speed.
  • the radial bore 70 is designed with a predetermined diameter, an aperture D2 limiting the maximum current being formed by this diameter.
  • Pressure compensator bore 58 an LS channel 82 through which the
  • Pressure in channel 78 can be tapped. This pressure corresponds to the load pressure of the consumer connected to the working connections A, B.
  • the pressure medium flows through the inner bore 68 and then enters the channel 78 via the opening cross section which is controlled by the control edge 72. Due to the axial displacement of the slide 8, the collar 28 is also shifted to the left, so that the connection from the channel 78 to the chamber 18 is opened - that Pressure medium flows via the chamber 18, the working channel 44 and the working connection A to the consumer, for example a differential cylinder.
  • the pressure medium returned by the consumer enters the directional valve arrangement 2 via the working connection B and flows out via the working channel 42 and the connection between the chamber 14 and the chamber 12, which is triggered by the annular collar 26, to the tank connection T.
  • the fine control notches 40 on the collar 36 determine the size of the regulated pressure medium flow in the small current range.
  • the pressure compensator piston 60 is on its right end face with the pressure upstream of the measuring orifice D1 (ring collar 36), i. H. pressurized at the pressure port P.
  • the force of the control spring 62 and, on the other hand, the pressure applied in the channel 78, and therefore the load pressure at the associated consumer acts on the pressure compensator piston 60.
  • the pressure compensator is pressurized with a pressure difference which corresponds to the pressure drop across the measuring orifice D1 (ring collar 36) and the orifice D2 (radial bore 70) which limits the maximum flow. This pressure difference corresponds to the force of the control spring 62.
  • the pressure compensator piston 60 of the pressure compensator 6 adjusts itself to a control position in which the
  • pressure drop across the orifice D1 and orifice D2 is kept constant regardless of the load pressure and the pump pressure, so that the pressure medium volume flow to the consumer is accordingly independent of pressure fluctuations.
  • the control edge 72 of the pressure compensator 6 is formed downstream of the measuring orifice D1 (and also the orifice D2 (radial bore 70) which limits the maximum flow) and upstream of the directional part of the proportional valve 8 formed by the annular collars 26, 28, 30 , This geometry enables the pressure compensator 6 to be arranged very close to the slide 8 with minimal modifications to the valve housing 2, so that a very compact solution is made possible.
  • FIG. 1 A simplified diagram of the directional control valve arrangement 1 is shown in FIG.
  • the dash-dotted line identifies the valve housing 2, on which the pressure connection P, a control or LS connection LS, a tank connection T and the two working connections A, B are formed.
  • the proportional valve 4 and the individual pressure compensator 6 are accommodated in the valve housing 2.
  • the pressure port P is connected via the pressure channel 46 and the upstream pressure compensator 6 to the input port of the proportional valve 4, which is practically formed by the chamber 24.
  • the two working connections A, B are connected via the two working channels 42, 44 to the output connections of the proportional valve 4, which are formed by the chambers 14 and 18 according to FIG. 1.
  • FIG. 2 The illustration according to FIG. 2 is simplified insofar as the pressure compensator 6 is connected upstream of the proportional valve 4, whereas in the concrete solution shown in FIG. 1 only the directional part of the proportional valve 4 and not the Measuring orifice is connected upstream.
  • the simplified diagram was chosen for the sake of clarity.
  • the proportional valve 4 also has a tank connection which is practically formed by the chambers 12, 20.
  • the load pressure is tapped via the LS channel 82.
  • the proportional valve 4 is biased by the force of the spring 48 into its basic position "0", in which the pressure port P and the working ports A, B are shut off, while the LS channel 82 is connected to the tank T.
  • the proportional valve 4 is actuated as described above via the handle, the working connection A is connected to the tank connection T and the measuring orifice D1 delimited by the collar 36 is opened.
  • the pressure downstream of the measuring orifice D1 (and the orifice D2 (radial bore 70) which limits the maximum flow) then acts in the direction of the control spring 62, i. H. in the opening direction on the pressure compensator 6, while the pressure at the pressure port P, d. H.
  • the pressure upstream of the orifice plate acts on the pressure compensator 6 in the closing direction.
  • the pressure compensator 6 is brought into a control position in which the pressure drop across the measuring orifice D1 is kept constant, so that the consumer is supplied with a constant pressure medium volume flow.
  • the pressure medium flowing back from the consumer comes back to the tank via the working connection B, the working channel 42, the proportional valve 4, a tank channel 84 and the tank connection T.
  • Directional valve arrangement can be provided with a check or non-return valve, which prevents a pressure medium flow from the consumer to the tank.
  • a check valve is provided in the area between the slide 8 of the proportional valve and the pressure compensator 6. Leak-free support of the consumer cannot, however, be guaranteed by such a check valve, since the pressure medium can flow out to the tank T via the sealing gaps of the proportional valve.
  • the check valves must therefore be provided between the consumer and the proportional valve for leak-free support.
  • Figure 3 The basic structure of this valve corresponds to that of Figure 2. That is.
  • a proportional valve 4 and an individual pressure compensator 6 are arranged parallel to one another, which in principle have the same structure as in the exemplary embodiment described above.
  • a proportional valve 4 and an individual pressure compensator 6 are arranged parallel to one another, which in principle have the same structure as in the exemplary embodiment described above.
  • FIG. 1 For the sake of simplicity, only the differences from the exemplary embodiment according to FIG. 1 are described below; for the rest, reference is made to the description of FIG. 1.
  • Lockable shut-off valves 86, 88 are provided in the working channels 42, 44 for leak-free support of the consumer. These check valves 86, 88 each have a valve body 90 which is biased against a valve seat 94 via a valve spring 92. Each of the valve bodies 90 has an axial projection in which a pin 96 is guided so as to be axially displaceable. This acts on a closing body 98 received in an inner bore of the valve body 90, which by a weak spring or the pressure at the associated consumer connection against an inner valve seat of the valve body 90 is biased. This inner valve seat is also connected to the assigned working connection B, A.
  • An actuating piston 100 is sealingly guided in a transverse bore connecting the two working channels 42, 44 and, in the event of an axial displacement, on the adjacent pin projecting from the valve body 90
  • valve body 90 of the shut-off valve 88 is lifted against the force of its valve spring 92 from the valve seat 94, so that the pressure medium with negligible pressure loss to the working connection A flows.
  • the actuating piston 100 is displaced to the left (FIG. 3) by the pressure in the working channel 44 and runs onto the pin 96 of the check valve 86. Due to the resulting axial displacement of the pin 96, the closing body 98 is lifted from its inner valve seat, so that pressure medium can flow from the working connection B into the working channel 42, so that the compressive force acting on the valve body 90 in the closing direction is reduced.
  • the valve body 90 can then be lifted off the valve seat 94 by the pressure acting on an annular shoulder 102 at the working connection B, so that the pressure medium can flow out from the working connection B to the tank connection T in the manner described above.
  • valve arrangement shown in FIG. 3 is that in the spring-biased basic position of the slide 8, the two chambers connected to the working channels 42, 44
  • Check valve 86 is opened much more slowly than would be the case with a variant with zero overlap or positive overlap. I.e. , by means of this throttle or bypass control, the actuation pressure upstream of the actuating piston 100 can be controlled, so that a sudden opening and thus relieving the load on the consumer can be prevented.
  • FIG. 4 shows a circuit diagram of the directional valve arrangement shown in FIG. 3, the case in which a load L is reduced in a controlled manner to be described. 4 shows the speed part of the proportional valve 4 from FIG. 4
  • the pressure compensator 6 Downstream of these two orifices D1, D2 is arranged the pressure compensator 6, which is acted upon in the direction of its open position by the control spring 62 and the pressure downstream of the two orifices Dl, D2 and in the closing direction by the pressure upstream of the measuring orifice Dl.
  • the pressure downstream of the pressure compensator 6 is tapped via the LS channel 82 and led to a shuttle valve arrangement 108. This is designed such that the highest load pressure of all consumers is reported to a variable pump 110 and this is controlled as a function of this maximum load pressure (LS control).
  • the orifice marked D3 in FIG. 4 represents the flow cross-section which is delimited by the annular collar 28 specifying the flow direction and the corresponding adjacent annular web of the valve bore 10.
  • the orifice marked D4 identifies the flow cross section which, at the beginning of the axial displacement of the slide 8, enables pressure medium to flow away from the pressurized working channel to the tank connection T. I.e. ,
  • the aperture D4 stands for the cross section, which is opened by the control edge 104 or 106.
  • the unlockable shut-off valve 88 assigned to the working connection A and the consumer 112 loaded with a pulling load L are also shown.
  • the orifice marked D4 ie the cross section connecting the working channel 42 to the space 12, is still open, so that pressure medium can initially flow out to the tank channel 84 via the orifice D4.
  • the diaphragm D4 With increasing axial displacement of the slide 8, the diaphragm D4 is closed and thus the bypass to the tank channel 84 is closed.
  • the unlocking pressure builds up in the working channel 42, which is required to unlock the shut-off valve 88 and to bring it into an opening position which enables a pressure medium backflow to the tank T.
  • FIG. 5 shows the qualitative course of a pressure control curve, the curve marked with (a) a variant without the bypass control described above (FIG. 1) and curve (b) the directional control valve arrangement with bypass control ((FIG. 3); working connections A, B in Basic position of the Proportional valve connected to the tank) shows.
  • the shut-off valve which enables the pressure medium return is quickly unlocked, so that the load L then abruptly drops and the acceleration energy to be absorbed in order to brake the load L leads to a pressure increase.
  • a directional valve arrangement in which an individual pressure compensator is assigned to a proportional valve forming a speed and a directional part, by means of which the pressure drop across the speed part of the proportional valve can be kept constant independently of the load pressure.
  • the control edge determining the throttle cross section of the individual pressure compensator is arranged in a flow path between the speed and the directional part of the proportional valve.
  • a bypass control is described which, when using shut-off valves, prevents a sudden unlocking of the shut-off valve which enables the pressure medium to return from the consumer. Bypas control is achieved by connecting the two working connections to the tank connection when the proportional valve is in the basic position.

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  • 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)

Abstract

L'invention concerne un ensemble distributeur (1), dans lequel une balance de pression individuelle est attribuée à une valve proportionnelle (4) formant une partie agissant sur la vitesse du fluide et une partie agissant sur la direction d'écoulement du fluide. Ladite balance de pression permet de maintenir la chute de pression à un niveau constant indépendamment de la pression de charge par l'intermédiaire de ladite partie agissant sur la vitesse. Selon la présente invention (6), l'arête de régulation (72), qui définit la section d'étranglement de la balance de pression individuelle, est située dans une voie d'écoulement entre lesdites parties agissant sur la vitesse et sur la direction. Cette invention concerne également une régulation par dérivation qui, lors de l'utilisation de clapets anti-retour (86, 88), empêche un déblocage brutal du clapet anti-retour, permettant le retour de fluide de pression depuis le consommateur. On obtient cette régulation par dérivation en reliant les deux raccords de travail (A, B) au raccord de réservoir (12, 20) en position initiale de la valve proportionnelle (4).
EP03704291A 2002-04-26 2003-02-04 Ensemble distributeur ls Withdrawn EP1499807A1 (fr)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
DE10218899 2002-04-26
DE10218899 2002-04-26
DE10245836 2002-10-01
DE10245836A DE10245836B4 (de) 2002-04-26 2002-10-01 LS-Wegeventilanordnung
PCT/DE2003/000311 WO2003091576A1 (fr) 2002-04-26 2003-02-04 Ensemble distributeur ls

Publications (1)

Publication Number Publication Date
EP1499807A1 true EP1499807A1 (fr) 2005-01-26

Family

ID=29271583

Family Applications (1)

Application Number Title Priority Date Filing Date
EP03704291A Withdrawn EP1499807A1 (fr) 2002-04-26 2003-02-04 Ensemble distributeur ls

Country Status (2)

Country Link
EP (1) EP1499807A1 (fr)
WO (1) WO2003091576A1 (fr)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ATE454561T1 (de) 2004-11-08 2010-01-15 Duplomatic Oleodinamica S P A Hydraulisches ls-wegeventil
CN113357432B (zh) * 2021-07-08 2022-06-21 河南航天液压气动技术有限公司 一种高精度易调节消声平衡阀

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3505623A1 (de) * 1985-02-19 1986-08-21 Robert Bosch Gmbh, 7000 Stuttgart Hydraulisches wegeventil fuer eine lastdruckkompensierte steuerung
DE3603811C2 (de) * 1986-02-07 1995-12-21 Bosch Gmbh Robert Hydraulisches Wegeventil
DE4136991C2 (de) * 1991-11-11 2000-11-02 Bosch Gmbh Robert Hydraulisches Wegeventil
DE4312257A1 (de) * 1993-04-15 1994-10-20 Bosch Gmbh Robert Hydraulische Steuereinrichtung
DE10027382A1 (de) * 2000-06-02 2001-12-06 Bosch Gmbh Robert Hydraulische Steuereinrichtung

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO03091576A1 *

Also Published As

Publication number Publication date
WO2003091576A1 (fr) 2003-11-06

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