EP0877169B1 - Hydraulic control device for the load-independent control of a double acting actuator - Google Patents

Hydraulic control device for the load-independent control of a double acting actuator Download PDF

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Publication number
EP0877169B1
EP0877169B1 EP98102270A EP98102270A EP0877169B1 EP 0877169 B1 EP0877169 B1 EP 0877169B1 EP 98102270 A EP98102270 A EP 98102270A EP 98102270 A EP98102270 A EP 98102270A EP 0877169 B1 EP0877169 B1 EP 0877169B1
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EP
European Patent Office
Prior art keywords
slide
control
pressure
control device
bore
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP98102270A
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German (de)
French (fr)
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EP0877169A3 (en
EP0877169A2 (en
Inventor
Wolfgang Koetter
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Robert Bosch GmbH
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Robert Bosch GmbH
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Filing date
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Publication of EP0877169A2 publication Critical patent/EP0877169A2/en
Publication of EP0877169A3 publication Critical patent/EP0877169A3/en
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Publication of EP0877169B1 publication Critical patent/EP0877169B1/en
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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
    • F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
    • F15B13/0416—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor with means or adapted for load sensing
    • F15B13/0417—Load sensing elements; Internal fluid connections therefor; Anti-saturation or pressure-compensation valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F15B11/161—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load
    • F15B11/163—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load for sharing the pump output equally amongst users or groups of users, e.g. using anti-saturation, pressure compensation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15C—FLUID-CIRCUIT ELEMENTS PREDOMINANTLY USED FOR COMPUTING OR CONTROL PURPOSES
    • F15C3/00—Circuit elements having moving parts
    • F15C3/06—Circuit elements having moving parts using balls or pill-shaped disks
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/30505—Non-return valves, i.e. check valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/30525—Directional control valves, e.g. 4/3-directional control valve
    • F15B2211/3053—In combination with a pressure compensating valve
    • F15B2211/30555—Inlet and outlet of the pressure compensating valve being connected to the directional control valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/31—Directional control characterised by the positions of the valve element
    • F15B2211/3105—Neutral or centre positions
    • F15B2211/3111—Neutral or centre positions the pump port being closed in the centre position, e.g. so-called closed centre
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/31—Directional control characterised by the positions of the valve element
    • F15B2211/3122—Special positions other than the pump port being connected to working ports or the working ports being connected to the return line
    • F15B2211/3127—Floating position connecting the working ports and the return line
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/35—Directional control combined with flow control
    • F15B2211/351—Flow control by regulating means in feed line, i.e. meter-in control
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/605—Load sensing circuits
    • F15B2211/6051—Load sensing circuits having valve means between output member and the load sensing circuit
    • F15B2211/6054—Load sensing circuits having valve means between output member and the load sensing circuit using shuttle valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/71—Multiple output members, e.g. multiple hydraulic motors or cylinders
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/78—Control of multiple output members

Definitions

  • the invention is based on a hydraulic Control device for load pressure independent control of a double-acting engine according to the in the preamble of Claim 1 specified genus.
  • Such a hydraulic control device is already used load pressure compensated control of a double acting Motors known from DE 36 34 728 C2, two of which Directional control valves for parallel actuation of the assigned Motors from a common variable displacement pump with pressure medium are supplied, the controller with a control line a shuttle valve chain with the maximum load pressure of the two motors is applied.
  • the pressure compensator used for load pressure compensation downstream of a metering orifice on the control slide, the Pressure compensator also used for direction control Piston sections of the control spool is connected upstream.
  • the Throttle valve in the downstream pressure compensator is in Opening direction from the pressure downstream of the orifice plate and in Closing direction of the highest load pressure and the Control pressure difference applied by the control spring.
  • DE 40 26 720 A1 is a hydraulic Control device for load pressure independent control of a known double-acting engine, in which a pressure compensator upstream of that formed on the spool Orifice plate is switched.
  • This directional valve can be used with a check valve separated from the pressure compensator Meet security requirements, with discharge of a cross channel between the check valve and orifice plate controlled via a piston section of the control slide which is also designed as a full slide valve. Also points the directional control valve has a second individual orifice Limit the oil flow to.
  • this directional valve with the Orifice plate upstream pressure compensator is Throttle slide in the closing direction from the pressure upstream of the Orifice plate on the control slide and in the opening direction from Pressure downstream of the orifice plate, i.e. plus the load pressure acted upon by the force of a spring.
  • the pressure compensator holds thus the pressure difference across the measuring throttle on the directional valve constant even with different load pressure, so that too the associated flow rate remains constant and the am Directional control valve set working speed is kept constant.
  • a disadvantage of this Control device is that it is not a supply dependent Allows oil flow sharing.
  • the hydraulic control device load-independent control of a double-acting Motors with the characterizing features of claim 1 on the other hand the advantage that they are at a supply-dependent oil flow distribution an increased degree Offers security and an extended usability. So can be separated by the arrangement of the pressure compensator of the check valve in connection with the control of the Pressure relief in the cross channel directly above the Control spool achieve that the load pressure with falling Pump pressure can be kept safer and faster. This also applies if the pressure in the control circuit Leakage or line break decreases.
  • the lines be formed as simply as possible in the control circuit, whereby Connecting lines in the control slide itself are omitted, see above that this as a simple, inexpensive building Full slide can be executed.
  • the directional valve with a fourth Equip switching position for an open gear the with the load pressure line connected to the pump is relieved.
  • a second individual orifice with this directional control valve integrate which the oil flow to the engine limited regardless of the deflection of the control spool.
  • FIG. 1 shows a longitudinal section through a hydraulic control device with a directional valve and Combined pressure compensator in a simplified representation
  • figure 2 as a detail a shuttle valve from a control circuit according to II-II in Figure 1
  • Figure 3 is a schematic Representation of a control block for two double-acting Motors with two control devices according to FIG. 1.
  • Figure 1 shows a longitudinal section through a hydraulic Control device 10 for load pressure-independent control of a double-acting engine.
  • the control device 10 are the actual directional control valve 11 in the load-sensing version and the associated pressure compensator 12 in one common housing 13 arranged.
  • the housing 13 has one between the two end faces continuous longitudinal bore 14, in the by annular Extensions trained a total of seven chambers 15 to 21 of which the five adjacent chambers 15 to 19 serve to control the direction of the pressure medium flow, while the two outer chambers 20, 21 one Measuring aperture 22 are assigned, which of Speed control of the engine is used.
  • the five adjacent chambers 15 to 19 serve the middle one Chamber as inlet chamber 17, while those lying next to it two chambers a first motor chamber 16 and a second Form motor chamber 18, which with a motor connection 23 or 24 are connected.
  • a return chamber 15 and 19, respectively, which are not shown in FIG drawn way with a return port in the housing 13 are connected.
  • 21 serves the first lying next to the second return chamber 19
  • Orifice chamber 20 as a discharge orifice chamber and the other as the inlet-side, second orifice chamber 21.
  • a spool 25 is tight and slidably guided.
  • the control slide 25 is by annular grooves divided into six piston sections 27 to 32.
  • the three adjacent piston sections 27, 28, 29 are with Control edges equipped and serve the direction control.
  • An adjoining fourth piston section 30, which in the drawn neutral position of the spool 25 in the outlet-side measuring orifice chamber 20 is used all to relieve a control circuit.
  • the one about it subsequent fifth piston section 31 is part of the Measuring aperture 22 and determines with its control edges Deflection of the control spool in both working positions the size of the volume flow to the motor and thus its speed.
  • the outer, sixth piston section 32 protrudes from the longitudinal bore 14 so that a attack actuator not shown can.
  • Control slide 25 with the first piston section 27 in one double-acting return device 33, the type of which is known per se and which the spool in its Neutral position 34 centered, out of which he in two Working positions 35 and 36 can be deflected. Furthermore, the Control slide 25 to a fourth switching position 37, which as Free position is executed.
  • FIG. 1 also shows, is in the housing 13 below the longitudinal bore 14 a second bore 39 and below a third bore 41 is arranged, all parallel to the Longitudinal bore 14 run.
  • the second bore 39 is trained like a blind hole and takes up inside Check valve 42 with its spherical closing member 43 on.
  • the discharge-side orifice chamber 20 a perpendicular to Spool 25 extending extension 45, which intersects the third bore 41.
  • Extension 45 also extends in the housing 13 perpendicular to the longitudinal slide 25 a circulation chamber 46, in whose end near the slide opens into the second bore 39, while with its end facing away from the longitudinal slide 25 penetrates the third bore 41. That way it forms one between the extension 45 and the circulation chamber 46 extending wall of the housing 13 an annular web 47, the both as a control edge for the second orifice 44, and serves for a throttle slide 48 of the pressure compensator 12.
  • the Throttle slide 48 is a hollow slide with a Blind bore 49 and a radial bore 51 executed, see above that he is in the starting position centered by the control spring 52 the circulation chamber 46 with the discharge-side orifice chamber 20 connects in a throttled manner.
  • the Throttle valve 48 is on its right front side Pressure in the extension 45 in the opening direction, that is acted against the force of the spring 52. In The closing direction acts on the throttle slide 48 the control spring 52 and the maximum load pressure in the spring chamber 53, via a control opening 54 from a control circuit is fed.
  • FIG. 1 also shows, lies in the second hole 39 in the area between the securing the inlet chamber 17 Check valve 42 and the circulation chamber 46 a Pressure tap opening 55, through which the maximum load pressure of the connected motor is tapped.
  • Form shuttle valve 56 and control channel 57 thereby parts of a known control circuit 58 in which in a manner known per se via shuttle valve chains maximum load pressure selected and for a load sensing control is used.
  • the two flange surfaces of the housing 13 connects to each other discharge-side orifice chamber 20 via a transverse channel 62 with the inlet chamber 17 in connection, in which Cross channel 62 one behind the other, the individual orifice 44, the Pressure compensator 12 and the separate check valve 42 are switched.
  • the throttle slide 48 is thus downstream of the orifice 22 and is such of Tax pressures that with him a supply-dependent oil flow distribution is achieved.
  • FIG. 3 shows a schematic representation of a Control block in which, in addition to the first control device 10 a similar, second control device 70 are flanged together so that at least two double-acting motors can be operated in parallel.
  • the Control devices 10, 70 are between one Connection plate 71 and an end plate 73 switched and connected in parallel to the continuous inlet channel 61.
  • the inlet channel 61 is from a pressure medium supply unit 73 supplied with pressure medium, with the Control circuit 58 of the maximum load pressure is returned.
  • the shuttle valves 56 form in both Control devices 10, 70 a valve chain, via which the maximum load pressure is selected or one Relief of the control circuit 58 is made.
  • control device 10 The operation of the control device 10 is as follows explained, the basic function of such Load-sensing valves are assumed to be known per se.
  • the pressure compensator 12 Measuring aperture 20 is connected downstream and is also upstream from the directional control edges in the directional control valve 11.
  • the LS pressure tap that is, the one that taps the load pressure Pressure tap opening 55 in the directional control valve 11 lies between the Pressure compensator 12 and the check valve 42, so that the respective pressure signal via the shuttle valve 56 in the Control circuit 58 is given.
  • the one in the control circuit 58 The selected, highest load pressure becomes pump 73 on the one hand and on the other hand into the spring chambers 53 of the pressure compensators 12 passed, this load pressure signal via control lines and the control openings 54 enter the spring chambers 53.
  • On the opposite end is the throttle slide 48 from the pressure downstream of the orifice 22 in the opening direction applied. This type of interconnection and the Pressurization of the throttle slide 48 enables one supply-dependent oil flow distribution at Parallel actuation of both control devices 10, 70.
  • control device 10 If the control device 10 is operated by itself and deflected into one of the working positions 35 or 36, so a load pressure independent control of the connected motor.
  • the throttle slide 48 in the pressure compensator 12 opens, controls he the relief connection via the radial bore 51.
  • the control edge also closes at the fourth piston section 30 the connection to the return chamber 19 before the orifice 22 opens. In this way there is no loss of oil to the return on.
  • the pressure compensator 12 maintains the pressure drop the measuring aperture 22 constant in a manner known per se, so that the speed of the motor proportional to the displacement of the spool 25 and regardless of Load pressure fluctuations is controlled. Should do this Leakage or a sticking shuttle valve the function of the Pressure compensator 12 may be impaired, in any case close the check valve 42 and prevent oil from the load flows towards the pump connection. Independent of the pressure conditions in the spring chamber 53 of the pressure compensator 12 a load on the motor becomes safe when the pump pressure drops held.
  • the check valve 42 designed as a seat valve ensures low leakage.
  • downstream Pressure compensator 12 which always keeps the pressure at the highest Load pressure plus regulating pressure difference regulates.
  • the Pressure differences at the orifice plates 22 become smaller and less oil flows to the engines.
  • the oil flow through the directional valves 11 increases in relation to the given Setpoints.
  • the directional valve 11 also has a fourth Switch position, this free position 37 by Pressing the control slide 25 into the housing 13 is achieved. Both are in this release position Motor connections 23, 24 with the return chambers 15 and 19 connected and the LS pressure line is relieved.
  • the volume flow can be independent of Limit the stroke of the control slide 25 for the directional valve 11, as is known in itself.
  • control spool 25 is designed as a full slide valve particularly advantageous combination.

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

Description

Stand der TechnikState of the art

Die Erfindung geht aus von einer hydraulischen Steuereinrichtung zur lastdruckunabhängigen Steuerung eines doppeltwirkenden Motors nach der im Oberbegriff des Anspruchs 1 näher angegebenen Gattung.The invention is based on a hydraulic Control device for load pressure independent control of a double-acting engine according to the in the preamble of Claim 1 specified genus.

Es ist schon eine solche hydraulische Steuereinrichtung zur lastdruckkompensierten Steuerung eines doppeltwirkenden Motors aus der DE 36 34 728 C2 bekannt, wobei zwei derartige Wegeventile für eine parallele Betätigung der zugeordneten Motoren von einer gemeinsamen Verstellpumpe mit Druckmittel versorgt werden, deren Regler über eine Steuerleitung mit einer Wechselventilkette mit dem jeweils maximalen Lastdruck der beiden Motoren beaufschlagt wird. Hier ist bei jedem Wegeventil die zur Lastdruckkompensation dienende Druckwaage einer Meßblende am Steuerschieber nachgeschaltet, wobei die Druckwaage zusätzlich den zur Richtungssteuerung dienenden Kolbenabschnitten des Steuerschiebers vorgeschaltet ist. Der Drosselschieber in der nachgeschalteten Druckwaage wird in Öffnungsrichtung vom Druck stromab der Meßblende und in Schließrichtung vom jeweils höchsten Lastdruck und der Regeldruckdifferenz durch die Regelfeder beaufschlagt. Mit dieser Anordnung läßt sich eine sog. versorgungsabhängige Ölstromaufteilung erreichen, wie sie in vielen Anwendungsfällen gefordert wird. Hier fließt bei Parallelbetätigung von zwei oder mehr Wegeventilen und nicht ausreichendem Pumpenölstrom, also bei einer Unterversorgung, gleichmäßig über alle Meßblenden weniger Öl. Die Druckdifferenzen an den jeweiligen Meßblenden werden dabei kleiner und es fließt weniger Öl zu den Motoren. Der Ölstrom durch die Wegeventile nimmt im Verhältnis zu den vorgegebenen Sollwerten ab. Es handelt sich also prinzipiell um eine Ventilanordnung zum Aufteilen des Pumpenstroms in einzelne, zu jedem Motor fließende Teilströme, wobei auch bei unterschiedlicher Belastung der Motoren das Teilungsverhältnis konstant bleibt und somit die Bewegungen aufrechterhalten werden, ohne daß es zu einem Stillstand des höchstbelasteten Motors kommt. Trotz der vorteilhaften Ölstromaufteilung hat diese hydraulische Steuereinrichtung doch den Nachteil mangelnder Sicherheit. So läßt sich der Lastdruck bei sinkendem Pumpendruck nicht ausreichend sicher halten, wenn im Steuerkreis der Druck zum Beispiel durch Leckage oder Leitungsbruch absinkt. Auch kann der Drosselschieber in der Druckwaage eine Rückschlagventilfunktion nicht ausreichend schnell wahrnehmen, da er über Steuerkreise mit Wechselventilketten angesteuert wird. Ferner weist das Wegeventil keine zweite, Individual-Meßblende auf, um den Ölstrom zu dem Motor unabhängig von der Schieberauslenkung zu begrenzen. Von Nachteil ist ferner, daß das Wegeventil keine vierte Schaltstellung für einen Freigang aufweist. Weiterhin ist es ungünstig, daß für die Ausbildung des Steuerkreises im Inneren des Steuerschiebers Verbindungsleitungen angeordnet werden müssen, um eine Entlastung zum Tank zu erreichen. Dies führt zu einer aufwendigen, kostspieligen Bauweise des Steuerschiebers. Such a hydraulic control device is already used load pressure compensated control of a double acting Motors known from DE 36 34 728 C2, two of which Directional control valves for parallel actuation of the assigned Motors from a common variable displacement pump with pressure medium are supplied, the controller with a control line a shuttle valve chain with the maximum load pressure of the two motors is applied. Here is with everyone Directional control valve the pressure compensator used for load pressure compensation downstream of a metering orifice on the control slide, the Pressure compensator also used for direction control Piston sections of the control spool is connected upstream. The Throttle valve in the downstream pressure compensator is in Opening direction from the pressure downstream of the orifice plate and in Closing direction of the highest load pressure and the Control pressure difference applied by the control spring. With this arrangement can be a so-called Achieve oil flow sharing like many Use cases is required. Flows in here Parallel actuation of two or more directional valves and not sufficient pump oil flow, i.e. in the event of an undersupply, less oil evenly over all orifices. The Pressure differences at the respective orifices are shown smaller and less oil flows to the engines. The oil flow through the directional valves increases in relation to the predetermined target values. So it is principally around a valve arrangement for dividing the pump flow into individual partial flows flowing to each motor, whereby also with different loads on the motors Division ratio remains constant and thus the movements be maintained without the plant coming to a standstill highly loaded engine comes. Despite the beneficial This hydraulic control device has oil flow distribution but the disadvantage of lack of security. So you can Load pressure is not sufficiently safe when the pump pressure drops if the pressure in the control circuit persists, for example Leakage or line break drops. He can also Throttle slide in the pressure compensator one Check valve function not fast enough perceive since it is via control circuits with shuttle valve chains is controlled. Furthermore, the directional valve has no second, Individual orifice on to the oil flow to the engine limit regardless of the slide deflection. Of Another disadvantage is that the directional valve is not a fourth Has switching position for an open gear. Furthermore it is unfavorable that for the formation of the control circuit in Arranged inside the control slide connecting lines need to be relieved to the tank. This leads to a complex, expensive construction of the Control slide.

Ferner ist aus der DE 40 26 720 A1 eine hydraulische Steuereinrichtung zur lastdruckunabhängigen Steuerung eines doppeltwirkenden Motors bekannt, bei der eine Druckwaage stromaufwärts von der am Steuerschieber ausgebildeten Meßblende geschaltet ist. Dieses Wegeventil kann mit einem von der Druckwaage getrennten Rückschlagventil erhöhte Sicherheitsanforderungen erfüllen, wobei die Entlastung eines Querkanals zwischen Rückschlagventil und Meßblende über einen Kolbenabschnitt des Steuerschiebers gesteuert wird, der zudem als Vollschieber ausgeführt ist. Auch weist das Wegeventil eine zweite Individual-Meßblende zur Begrenzung des Ölstroms auf. Bei diesem Wegeventil mit der Meßblende vorgeschalteter Druckwaage wird deren Drosselschieber in Schließrichtung vom Druck stromauf der Meßblende am Steuerschieber und in Öffnungsrichtung vom Druck stromab der Meßblende, also vom Lastdruck zuzüglich der Kraft einer Feder beaufschlagt. Die Druckwaage hält somit die Druckdifferenz über die Meßdrossel am Wegeventil auch bei unterschiedlichem Lastdruck konstant, so daß auch der zugehörige Durchfluß konstant bleibt und die am Wegeventil eingestellte Arbeitsbeschwindigkeit konstantgehalten wird. Von Nachteil bei dieser Steuereinrichtung ist, daß sie keine versorgungsabhängige Ölstromaufteilung ermöglicht. Werden mit solchen Wegeventilen mehrere Motoren im Parallelbetrieb gleichzeitig gesteuert, so wird zuerst der Motor mit dem niedrigsten Lastdruck mit einem Druckmittelstrom versorgt, während der übrige Rest des Volumenstroms zu den anderen Motoren geleitet wird. Dadurch ändert sich das Verhältnis der Aufteilung der Volumenströme, das hier nicht konstant bleibt. Gerade bei Unterversorgung kann dies dazu führen, daß die Funktion des am niedrigsten belasteten Motors erhalten bleibt, während der hochbelastete, parallel betätigte Motor stehen bleibt, was in vielen Anwendungsfällen nicht erwünscht ist. Furthermore, from DE 40 26 720 A1 is a hydraulic Control device for load pressure independent control of a known double-acting engine, in which a pressure compensator upstream of that formed on the spool Orifice plate is switched. This directional valve can be used with a check valve separated from the pressure compensator Meet security requirements, with discharge of a cross channel between the check valve and orifice plate controlled via a piston section of the control slide which is also designed as a full slide valve. Also points the directional control valve has a second individual orifice Limit the oil flow to. With this directional valve with the Orifice plate upstream pressure compensator is Throttle slide in the closing direction from the pressure upstream of the Orifice plate on the control slide and in the opening direction from Pressure downstream of the orifice plate, i.e. plus the load pressure acted upon by the force of a spring. The pressure compensator holds thus the pressure difference across the measuring throttle on the directional valve constant even with different load pressure, so that too the associated flow rate remains constant and the am Directional control valve set working speed is kept constant. A disadvantage of this Control device is that it is not a supply dependent Allows oil flow sharing. Be with such Directional control valves for several motors in parallel operation is controlled, the motor with the lowest is first Load pressure supplied with a pressure medium stream during the remaining rest of the volume flow to the other motors is directed. This changes the ratio of Distribution of volume flows, which is not constant here remains. In the case of undersupply, this can lead to that the function of the least loaded engine is preserved, while the heavily loaded, parallel actuated engine stops, which in many Use cases is not desirable.

Vorteile der ErfindungAdvantages of the invention

Die erfindungsgemäße hydraulische Steuereinrichtung zur lastdruckunabhängigen Steuerung eines doppeltwirkenden Motors mit den kennzeichnenden Merkmalen des Anspruchs 1 hat demgegenüber den Vorteil, daß sie bei einer versorgungsabhängigen Ölstromaufteilung ein erhöhtes Maß an Sicherheit und eine erweiterte Einsatzfähigkeit bietet. So läßt sich durch die von der Druckwaage getrennte Anordnung des Rückschlagventils in Verbindung mit der Steuerung der Druckentlastung im Querkanal unmittelbar über den Steuerschieber erreichen, daß der Lastdruck bei sinkendem Pumpendruck sicherer und schneller gehalten werden kann. Dies gilt auch dann, wenn im Steuerkreis der Druck durch Leckage oder Leitungsbruch sinkt. Dabei können die Leitungen im Steuerkreis möglichst einfach ausgebildet werden, wobei Verbindungsleitungen im Steuerschieber selbst entfallen, so daß dieser als einfacher, kostengünstig bauender Vollschieber ausgeführt werden kann. Ferner läßt sich bei dieser Bauweise das Wegeventil mit einer vierten Schaltstellung für einen Freigang ausrüsten, wobei die mit der Pumpe verbundene Lastdruckleitung entlastet ist. Ferner läßt sich bei diesem Wegeventil eine zweite Individual-Meßblende integrieren, welche den Ölstrom zu dem Motor unabhängig von der Auslenkung des Steuerschiebers begrenzt. Insgesamt ermöglicht die Steuereinrichtung eine relativ einfache und kompakte Bauweise. Weitere vorteilhafte Ausgestaltungen ergeben sich aus den Unteransprüchen, der Beschreibung sowie der Zeichnung.The hydraulic control device according to the invention load-independent control of a double-acting Motors with the characterizing features of claim 1 on the other hand the advantage that they are at a supply-dependent oil flow distribution an increased degree Offers security and an extended usability. So can be separated by the arrangement of the pressure compensator of the check valve in connection with the control of the Pressure relief in the cross channel directly above the Control spool achieve that the load pressure with falling Pump pressure can be kept safer and faster. This also applies if the pressure in the control circuit Leakage or line break decreases. The lines be formed as simply as possible in the control circuit, whereby Connecting lines in the control slide itself are omitted, see above that this as a simple, inexpensive building Full slide can be executed. Furthermore, can this design, the directional valve with a fourth Equip switching position for an open gear, the with the load pressure line connected to the pump is relieved. Further can be a second individual orifice with this directional control valve integrate which the oil flow to the engine limited regardless of the deflection of the control spool. Overall, the control device enables a relative simple and compact design. More beneficial Refinements result from the dependent claims, the Description as well as the drawing.

Zeichnungdrawing

Ein Ausführungsbeispiel der Erfindung ist in der Zeichnung dargestellt und in der nachfolgenden Beschreibung näher erläutert. Es zeigen Figur 1 einen Längsschnitt durch eine hydraulische Steuereinrichtung mit einem Wegeventil und kombinierter Druckwaage in vereinfachter Darstellung, Figur 2 als Einzelheit ein Wechselventil aus einem Steuerkreis nach II-II in Figur 1, und Figur 3 eine schematische Darstellung eines Steuerblocks für zwei doppeltwirkende Motoren mit zwei Steuereinrichtungen nach Figur 1.An embodiment of the invention is in the drawing shown and in the description below explained. 1 shows a longitudinal section through a hydraulic control device with a directional valve and Combined pressure compensator in a simplified representation, figure 2 as a detail a shuttle valve from a control circuit according to II-II in Figure 1, and Figure 3 is a schematic Representation of a control block for two double-acting Motors with two control devices according to FIG. 1.

Beschreibung der AusführungsbeispieleDescription of the embodiments

Die Figur 1 zeigt einen Längsschnitt durch eine hydraulische Steuereinrichtung 10 zur lastdruckunabhängigen Steuerung eines doppeltwirkenden Motors. Bei der Steuereinrichtung 10 sind das eigentliche Wegeventil 11 in Load-Sensing-Ausführung sowie die zugeordnete Druckwaage 12 in einem gemeinsamen Gehäuse 13 angeordnet.Figure 1 shows a longitudinal section through a hydraulic Control device 10 for load pressure-independent control of a double-acting engine. In the control device 10 are the actual directional control valve 11 in the load-sensing version and the associated pressure compensator 12 in one common housing 13 arranged.

Das Gehäuse 13 hat eine zwischen beiden Stirnseiten durchgehende Längsbohrung 14, in der durch ringförmige Erweiterungen insgesamt sieben Kammern 15 bis 21 ausgebildet sind, von denen die fünf nebeneinander liegenden Kammern 15 bis 19 der Richtungssteuerung des Druckmittelstroms dienen, während die beiden außenliegenden Kammern 20, 21 einer Meßblende 22 zugeordnet sind, welche der Geschwindigkeitssteuerung des Motors dient. Von den fünf nebeneinanderliegenden Kammern 15 bis 19 dient die mittlere Kammer als Zulaufkammer 17, während die neben ihr liegenden beiden Kammern eine erste Motorkammer 16 und eine zweite Motorkammer 18 bilden, die mit einem Motoranschluß 23 bzw. 24 in Verbindung stehen. Neben jeder Motorkammer 16, 18 liegt eine Rücklaufkammer 15 bzw. 19, die in nicht näher gezeichneter Weise mit einem Rücklaufanschluß im Gehäuse 13 verbunden sind. Von den beiden Meßblendenkammern 20, 21 dient die neben der zweiten Rücklaufkammer 19 liegende erste Meßblendenkammer 20 als ablaufseitige Meßblendenkammer und die andere als zulaufseitige, zweite Meßblendenkammer 21.The housing 13 has one between the two end faces continuous longitudinal bore 14, in the by annular Extensions trained a total of seven chambers 15 to 21 of which the five adjacent chambers 15 to 19 serve to control the direction of the pressure medium flow, while the two outer chambers 20, 21 one Measuring aperture 22 are assigned, which of Speed control of the engine is used. Of the five adjacent chambers 15 to 19 serve the middle one Chamber as inlet chamber 17, while those lying next to it two chambers a first motor chamber 16 and a second Form motor chamber 18, which with a motor connection 23 or 24 are connected. In addition to each motor chamber 16, 18 there is a return chamber 15 and 19, respectively, which are not shown in FIG drawn way with a return port in the housing 13 are connected. Of the two orifice chambers 20, 21 serves the first lying next to the second return chamber 19 Orifice chamber 20 as a discharge orifice chamber and the other as the inlet-side, second orifice chamber 21.

In der Längsbohrung 14 ist ein Steuerschieber 25 dicht und gleitend geführt. Der Steuerschieber 25 ist durch Ringnuten in sechs Kolbenabschnitte 27 bis 32 unterteilt. Die drei nebeneinanderliegenden Kolbenabschnitte 27, 28, 29 sind mit Steuerkanten ausgerüstet und dienen der Richtungssteuerung. Ein daran angrenzender, vierter Kolbenabschnitt 30, der in der gezeichneten Neutralstellung des Steuerschiebers 25 in der ablaufseitigen Meßblendenkammer 20 liegt, dient vor allem zur Entlastung eines Steuerkreises. Der daran anschließende fünfte Kolbenabschnitt 31 ist Teil der Meßblende 22 und bestimmt mit seinen Steuerkanten bei Auslenkung des Steuerschiebers in beide Arbeitsstellungen jeweils die Größe des Volumenstroms zum Motor und damit dessen Geschwindigkeit. Der äußere, sechste Kolbenabschnitt 32 ragt aus der Längsbohrung 14 heraus, so daß an ihm eine nicht näher gezeichnete Betätigungseinrichtung angreifen kann. An seinem entgegengesetzten Ende ragt der Steuerschieber 25 mit dem ersten Kolbenabschnitt 27 in eine doppeltwirkende Rückholeinrichtung 33 hinein, deren Bauart an sich bekannt ist und die den Steuerschieber in seiner Neutralstellung 34 zentriert, aus der heraus er in zwei Arbeitsstellungen 35 und 36 auslenkbar ist. Ferner weist der Steuerschieber 25 eine vierte Schaltstellung 37 auf, die als Freigang-Stellung ausgeführt ist.In the longitudinal bore 14, a spool 25 is tight and slidably guided. The control slide 25 is by annular grooves divided into six piston sections 27 to 32. The three adjacent piston sections 27, 28, 29 are with Control edges equipped and serve the direction control. An adjoining fourth piston section 30, which in the drawn neutral position of the spool 25 in the outlet-side measuring orifice chamber 20 is used all to relieve a control circuit. The one about it subsequent fifth piston section 31 is part of the Measuring aperture 22 and determines with its control edges Deflection of the control spool in both working positions the size of the volume flow to the motor and thus its speed. The outer, sixth piston section 32 protrudes from the longitudinal bore 14 so that a attack actuator not shown can. The protrudes at its opposite end Control slide 25 with the first piston section 27 in one double-acting return device 33, the type of which is known per se and which the spool in its Neutral position 34 centered, out of which he in two Working positions 35 and 36 can be deflected. Furthermore, the Control slide 25 to a fourth switching position 37, which as Free position is executed.

Wie die Figur 1 ferner zeigt, ist im Gehäuse 13 unterhalb der Längsbohrung 14 eine zweite Bohrung 39 und darunter noch eine dritte Bohrung 41 angeordnet, die alle parallel zur Längsbohrung 14 verlaufen. Die zweite Bohrung 39 ist sacklochartig ausgebildet und nimmt in ihrem Inneren ein Rückschlagventil 42 mit seinem kugeligen Schließglied 43 auf. Demgegenüber verläuft die dritte, mehrfach abgesetzte Bohrung 41 zwischen beiden Stirnseiten des Gehäuses 13 und nimmt neben der Druckwaage 12 auch eine zweite Individual-Meßblende 44 auf. Um dies zu ermöglichen weist die ablaufseitige Meßblendenkammer 20 eine senkrecht zum Steuerschieber 25 sich erstreckende Verlängerung 45 auf, welche die dritte Bohrung 41 schneidet. Neben dieser Verlängerung 45 erstreckt sich im Gehäuse 13 ebenfalls senkrecht zum Längsschieber 25 eine Umlaufkammer 46, in deren schiebernahem Ende die zweite Bohrung 39 einmündet, während sie mit ihrem vom Längsschieber 25 abgewandten Ende die dritte Bohrung 41 durchdringt. Auf diese Weise bildet eine zwischen der Verlängerung 45 und der Umlaufkammer 46 verlaufende Wand des Gehäuses 13 einen Ringsteg 47, der sowohl als Steuerkante für die zweite Meßblende 44, als auch für einen Drosselschieber 48 der Druckwaage 12 dient. Der Drosselschieber 48 ist als Hohlschieber mit einer Sacklochbohrung 49 und einer Radialbohrung 51 ausgeführt, so daß er in der von der Regelfeder 52 zentrierten Ausgangslage die Umlaufkammer 46 mit der ablaufseitigen Meßblendenkammer 20 in gedrosselter Weise verbindet. Wenn der Drosselschieber 48 im Betrieb seine Arbeitsstellung einnimmt, ist diese Verbindung über die Radialbohrung 51 zugesteuert. Der Drosselschieber 48 wird auf seiner rechten Stirnseite vom Druck in der Verlängerung 45 in Öffnungsrichtung, also entgegen der Kraft der Feder 52 beaufschlagt. In Schließrichtung wirken auf den Drosselschieber 48 die Kraft der Regelfeder 52 und der maximale Lastdruck im Federraum 53, der über eine Steueröffnung 54 aus einem Steuerkreis zugeführt wird.As FIG. 1 also shows, is in the housing 13 below the longitudinal bore 14 a second bore 39 and below a third bore 41 is arranged, all parallel to the Longitudinal bore 14 run. The second bore 39 is trained like a blind hole and takes up inside Check valve 42 with its spherical closing member 43 on. In contrast, there is the third, multiple offset Bore 41 between the two end faces of the housing 13 and in addition to the pressure compensator 12 also takes a second individual orifice plate 44 on. To make this possible, the discharge-side orifice chamber 20 a perpendicular to Spool 25 extending extension 45, which intersects the third bore 41. Besides this Extension 45 also extends in the housing 13 perpendicular to the longitudinal slide 25 a circulation chamber 46, in whose end near the slide opens into the second bore 39, while with its end facing away from the longitudinal slide 25 penetrates the third bore 41. That way it forms one between the extension 45 and the circulation chamber 46 extending wall of the housing 13 an annular web 47, the both as a control edge for the second orifice 44, and serves for a throttle slide 48 of the pressure compensator 12. The Throttle slide 48 is a hollow slide with a Blind bore 49 and a radial bore 51 executed, see above that he is in the starting position centered by the control spring 52 the circulation chamber 46 with the discharge-side orifice chamber 20 connects in a throttled manner. If the throttle valve 48 occupies his working position in the company Connection controlled via the radial bore 51. The Throttle valve 48 is on its right front side Pressure in the extension 45 in the opening direction, that is acted against the force of the spring 52. In The closing direction acts on the throttle slide 48 the control spring 52 and the maximum load pressure in the spring chamber 53, via a control opening 54 from a control circuit is fed.

Wie die Figur 1 ferner zeigt, liegt in der zweiten Bohrung 39 im Bereich zwischen dem die Zulaufkammer 17 absichernden Rückschlagventil 42 und der Umlaufkammer 46 eine Druckabgriffsöffnung 55, über welche der maximale Lastdruck des angeschlossenen Motors abgegriffen wird. Wie die Figur 2 als Einzelheit näher zeigt, wird dieses Drucksignal aus der Druckabgriffsöffnung 55 im Wegeventil 11 in einem Wechselventil 56 mit einem anderen Drucksignal aus einem zweiten Wegeventil 70 verglichen und das ausgewählte maximale Lastdrucksignal über einen Steuerkanal 57 weitergeleitet. Wechselventil 56 und Steuerkanal 57 bilden dabei Teile eines an sich bekannten Steuerkreises 58, in dem in an sich bekannter Weise über Wechselventilketten der maximale Lastdruck ausgewählt und für eine Load-Sensing-Steuerung verwendet wird.As FIG. 1 also shows, lies in the second hole 39 in the area between the securing the inlet chamber 17 Check valve 42 and the circulation chamber 46 a Pressure tap opening 55, through which the maximum load pressure of the connected motor is tapped. Like the figure 2 shows as a detail, this pressure signal from the Pressure tap opening 55 in the directional control valve 11 in one Shuttle valve 56 with a different pressure signal from one second directional control valve 70 compared and the selected maximum load pressure signal via a control channel 57 forwarded. Form shuttle valve 56 and control channel 57 thereby parts of a known control circuit 58 in which in a manner known per se via shuttle valve chains maximum load pressure selected and for a load sensing control is used.

Während die zulaufseitige Meßblendenkammer 21 mit einem Zulaufkanal 61 verbunden ist, der die beiden Flanschflächen des Gehäuses 13 miteinander verbindet, steht die ablaufseitige Meßblendenkammer 20 über einen Querkanal 62 mit der Zulaufkammer 17 in Verbindung, wobei in diesen Querkanal 62 hintereinander die Individual-Meßblende 44, die Druckwaage 12 und das gesonderte Rückschlagventil 42 geschaltet sind. Der Drosselschieber 48 liegt somit stromabwärts von der Meßblende 22 und ist derart von Steuerdrücken beaufschlagt, daß mit ihm eine versorgungsabhängige Ölstromaufteilung erreicht wird.While the inlet-side orifice chamber 21 with a Inlet channel 61 is connected, the two flange surfaces of the housing 13 connects to each other discharge-side orifice chamber 20 via a transverse channel 62 with the inlet chamber 17 in connection, in which Cross channel 62 one behind the other, the individual orifice 44, the Pressure compensator 12 and the separate check valve 42 are switched. The throttle slide 48 is thus downstream of the orifice 22 and is such of Tax pressures that with him a supply-dependent oil flow distribution is achieved.

Die Figur 3 zeigt in schematischer Darstellung einen Steuerblock, bei dem neben der ersten Steuereinrichtung 10 eine gleichartige, zweite Steuereinrichtung 70 aneinandergeflanscht sind, so daß wenigstens zwei doppeltwirkende Motoren parallel betätigbar sind. Die Steuereinrichtungen 10, 70 sind zwischen einer Anschlußplatte 71 und einer Endplatte 73 geschaltet und parallel an den durchgehenden Zulaufkanal 61 angeschlossen. Der Zulaufkanal 61 wird von einer Druckmittelversorgungseinheit 73 mit Druckmittel versorgt, wobei über den Steuerkreis 58 der maximale Lastdruck zurückgeführt wird. Dazu bilden die Wechselventile 56 in beiden Steuereinrichtungen 10, 70 eine Ventilkette, über welche der jeweils maximale Lastdruck ausgewählt wird bzw. eine Entlastung des Steuerkreises 58 vorgenommen wird.Figure 3 shows a schematic representation of a Control block in which, in addition to the first control device 10 a similar, second control device 70 are flanged together so that at least two double-acting motors can be operated in parallel. The Control devices 10, 70 are between one Connection plate 71 and an end plate 73 switched and connected in parallel to the continuous inlet channel 61. The inlet channel 61 is from a pressure medium supply unit 73 supplied with pressure medium, with the Control circuit 58 of the maximum load pressure is returned. For this purpose, the shuttle valves 56 form in both Control devices 10, 70 a valve chain, via which the maximum load pressure is selected or one Relief of the control circuit 58 is made.

Die Wirkungsweise der Steuereinrichtung 10 wird wie folgt erläutert, wobei die grundsätzliche Funktion derartiger Load-Sensing-Ventile als an sich bekannt vorausgesetzt wird. Bei den untereinander gleichen, parallel geschalteten Steuereinrichtungen 10, 70 ist die Druckwaage 12 der Meßblende 20 jeweils nachgeschaltet und liegt zudem stromauf von den Richtungs-Steuerkanten im Wegeventil 11. Der LS-Druckabgriff, also die den Lastdruck abgreifende Druckabgriffsöffnung 55 im Wegeventil 11, liegt zwischen der Druckwaage 12 und dem Rückschlagventil 42, so daß das jeweilige Drucksignal über das Wechselventil 56 in den Steuerkreis 58 gegeben wird. Der im Steuerkreis 58 ausgewählte, höchste Lastdruck wird einerseits zur Pumpe 73 und andererseits in die Federräume 53 der Druckwaagen 12 geleitet, wobei dieses Lastdrucksignal über Steuerleitungen und die Steueröffnungen 54 in die Federräume 53 gelangt. Auf der entgegengesetzten Stirnseite ist der Drosselschieber 48 vom Druck stromabwärts der Meßblende 22 in Öffnungsrichtung beaufschlagt. Diese Art der Verschaltung und der Druckbeaufschlagung des Drosselschiebers 48 ermöglicht eine versorgungsabhängige Ölstromaufteilung bei Parallelbetätigung beider Steuereinrichtungen 10, 70.The operation of the control device 10 is as follows explained, the basic function of such Load-sensing valves are assumed to be known per se. With the same, connected in parallel Control devices 10, 70 is the pressure compensator 12 Measuring aperture 20 is connected downstream and is also upstream from the directional control edges in the directional control valve 11. The LS pressure tap, that is, the one that taps the load pressure Pressure tap opening 55 in the directional control valve 11 lies between the Pressure compensator 12 and the check valve 42, so that the respective pressure signal via the shuttle valve 56 in the Control circuit 58 is given. The one in the control circuit 58 The selected, highest load pressure becomes pump 73 on the one hand and on the other hand into the spring chambers 53 of the pressure compensators 12 passed, this load pressure signal via control lines and the control openings 54 enter the spring chambers 53. On the opposite end is the throttle slide 48 from the pressure downstream of the orifice 22 in the opening direction applied. This type of interconnection and the Pressurization of the throttle slide 48 enables one supply-dependent oil flow distribution at Parallel actuation of both control devices 10, 70.

In der Neutralstellung 34, wie dies in Figur 1 und Figur 3 näher dargestellt ist, ist der an der Druckabgriffsöffnung 55 hängende Steuerkreis 58 über die Umlaufkammer 46, die aufgesteuerte Radialbohrung 51 und die Sacklochbohrung 59 im Drosselschieber 48, die Verlängerung 45, die ablaufseitige Meßblendenkammer 20 sowie die offene Steuerkante am vierten Kolbenabschnitt 30 zur zweiten Rücklaufkammer 19 entlastet. Damit wird auch die Pumpe 73 auf einen niedrigen Ausgangsdruck geregelt. Diese Entlastung der LS-Druckleitung über die Druckwaage 12 und den Steuerschieber 25 baut besonders einfach und ermöglicht eine Ausbildung des Steuerschiebers 25 als Vollschieber, der somit keine internen Verbindungsbohrungen aufweist. Die gleiche Art der Entlastung läßt sich auch erreichen, wenn der Steuerschieber 25 seine vierte Schaltstellung 37 für Freigang einnimmt.In the neutral position 34, as shown in FIG. 1 and FIG. 3 is shown in more detail, is that at the pressure tap opening 55 hanging control circuit 58 via the circulation chamber 46, the controlled radial bore 51 and the blind bore 59 in Throttle slide 48, the extension 45, the outlet side Orifice chamber 20 and the open control edge on the fourth Piston section 30 to the second return chamber 19 is relieved. This also lowers the pump 73 Output pressure regulated. This relieves the LS pressure line builds on the pressure compensator 12 and the spool 25 particularly simple and enables training of Control spool 25 as a full spool, which is therefore no internal connection holes. The same kind of Relief can also be achieved if the control spool 25 occupies its fourth switching position 37 for clearance.

Wird die Steuereinrichtung 10 für sich allein betätigt und dabei in eine der Arbeitsstellungen 35 oder 36 ausgelenkt, so läßt sich eine lastdruckunabhängige Steuerung des angeschlossenen Motors erzielen. Der von der Druckmittelversorgungseinheit 73 über den Zulaufkanal 61 ankommende Volumenstrom fließt über die aufgesteuerte Meßblende 22 und die nachgeschaltete Druckwaage 12 sowie das Rückschlagventil 42 in die Zulaufkammer 17 und weiter zum Motor bzw. vom Motor in den Rücklauf zurück. Bevor hierbei der Drosselschieber 48 in der Druckwaage 12 öffnet, steuert er die entlastende Verbindung über die Radialbohrung 51 zu. Ebenso schließt die Steuerkante am vierten Kolbenabschnitt 30 die Verbindung zur Rücklaufkammer 19, bevor die Meßblende 22 öffnet. Auf diese Weise tritt kein Ölverlust zum Rücklauf auf. Die Druckwaage 12 hält hierbei das Druckgefälle über die Meßblende 22 in an sich bekannter Weise konstant, so daß die Geschwindigkeit des Motors proportional zur Auslenkung des Steuerschiebers 25 und dabei unabhängig von Lastdruckschwankungen gesteuert wird. Sollte dabei durch Leckage oder ein klemmendes Wechselventil die Funktion der Druckwaage 12 beeinträchtigt sein, so kann auf jeden Fall das Rückschlagventil 42 schließen und verhindern, daß Öl von der Last in Richtung Pumpenanschluß fließt. Unabhängig von den Druckverhältnissen im Federraum 53 der Druckwaage 12 wird eine Last am Motor bei sinkendem Pumpendruck sicher gehalten. Das als Sitzventil ausgeführte Rückschlagventil 42 sorgt für eine geringe Leckage. If the control device 10 is operated by itself and deflected into one of the working positions 35 or 36, so a load pressure independent control of the connected motor. The one from the Pressure medium supply unit 73 via the inlet channel 61 incoming volume flow flows via the controlled Orifice plate 22 and the downstream pressure compensator 12 and that Check valve 42 in the inlet chamber 17 and on to Motor or from the motor back into the return. Before doing this the throttle slide 48 in the pressure compensator 12 opens, controls he the relief connection via the radial bore 51. The control edge also closes at the fourth piston section 30 the connection to the return chamber 19 before the orifice 22 opens. In this way there is no loss of oil to the return on. The pressure compensator 12 maintains the pressure drop the measuring aperture 22 constant in a manner known per se, so that the speed of the motor proportional to the displacement of the spool 25 and regardless of Load pressure fluctuations is controlled. Should do this Leakage or a sticking shuttle valve the function of the Pressure compensator 12 may be impaired, in any case close the check valve 42 and prevent oil from the load flows towards the pump connection. Independent of the pressure conditions in the spring chamber 53 of the pressure compensator 12 a load on the motor becomes safe when the pump pressure drops held. The check valve 42 designed as a seat valve ensures low leakage.

Werden beide Steuereinrichtungen 10, 70 parallel betätigt, so ergibt sich eine versorgungsabhängige Ölstromaufteilung, die auch als sog. soziales Verhalten bezeichnet wird.If both control devices 10, 70 are operated in parallel, this results in a supply-dependent oil flow distribution, which is also referred to as so-called social behavior.

Dabei ist also der jeweils höchste, an einem der Motoren auftretende Lastdruck an alle Druckwaagen 12 der Steuereinrichtungen 10 und 70 angelegt. Damit stellen sich die Drosselschieber 48 beider Druckwaagen 12 so ein, daß an ihren der jeweiligen Meßblende 22 zugekehrten Stirnseiten auch bei unterschiedlicher Belastung der Motoren stets gleicher Druck herrscht, so daß die Meßblenden 22 von im Verhältnis zueinander stets konstanten Druckmittelmengen durchflossen werden. Es handelt sich also prinzipiell um eine Ventilanordnung zum Aufteilen des Pumpenstroms in einzelne, zu jedem Motor fließende Teilströme, wobei auch bei unterschiedlicher Belastung der Motoren das Teilungsverhältnis konstant bleibt und damit die gewünschte Geschwindigkeit aufrechterhalten bleibt. Fließt bei dieser Parallelbetätigung beider Steuereinrichtungen 10, 70 kein ausreichender Pumpenölstrom, so daß eine Unterversorgung vorliegt, so fließt gleichmäßig über alle Meßblenden 22 entsprechend weniger Öl. Dafür sorgt die nachgeschaltete Druckwaage 12, die den Druck stets auf den höchsten Lastdruck plus Regeldruckdifferenz regelt. Die Druckdifferenzen an den Meßblenden 22 werden dabei kleiner und es fließt weniger Öl zu den Motoren. Der Ölstrom durch die Wegeventile 11 nimmt im Verhältnis zu den vorgegebenen Sollwerten ab.The highest is on one of the motors occurring load pressure to all pressure compensators 12 the Control devices 10 and 70 created. With that, pose the throttle slide 48 of both pressure compensators 12 so that at their end faces facing the respective measuring aperture 22 always with different loads on the motors the same pressure prevails, so that the orifice 22 from im Relative to each other constant amounts of pressure medium be flowed through. In principle, it is about a valve arrangement for dividing the pump flow into individual partial flows flowing to each motor, whereby also with different loads on the motors Division ratio remains constant and thus the desired Speed is maintained. Flows at this Parallel actuation of both control devices 10, 70 none sufficient pump oil flow so that an undersupply is present, then flows evenly over all orifices 22 correspondingly less oil. This is ensured by the downstream Pressure compensator 12, which always keeps the pressure at the highest Load pressure plus regulating pressure difference regulates. The Pressure differences at the orifice plates 22 become smaller and less oil flows to the engines. The oil flow through the directional valves 11 increases in relation to the given Setpoints.

Das Wegeventil 11 hat darüberhinaus eine vierte Schaltstellung, wobei diese Freigangstellung 37 durch Drücken des Steuerschiebers 25 in das Gehäuse 13 hinein erreicht wird. In dieser Freigangstellung sind beide Motoranschlüsse 23, 24 mit den Rücklaufkammern 15 bzw. 19 verbunden und zudem ist die LS-Druckleitung entlastet.The directional valve 11 also has a fourth Switch position, this free position 37 by Pressing the control slide 25 into the housing 13 is achieved. Both are in this release position Motor connections 23, 24 with the return chambers 15 and 19 connected and the LS pressure line is relieved.

Mit der zweiten Individual-Meßblende 44, die zwischen die Meßblende 22 am Steuerschieber 25 und die Druckwaage 12 geschaltet ist, läßt sich der Volumenstrom unabhängig vom Hub des Steuerschiebers 25 für das Wegeventil 11 begrenzen, wie dies an sich bekannt ist.With the second individual orifice 44, which between the Orifice plate 22 on control slide 25 and pressure compensator 12 is switched, the volume flow can be independent of Limit the stroke of the control slide 25 for the directional valve 11, as is known in itself.

Die Ausbildung der Steuereinrichtung 10 mit einer der Meßblende 22 am Steuerschieber 25 nachgeschalteten Druckwaage 12, mit dem von der Druckwaage 12 getrennten Rückschlagventil 42 und mit der Entlastung der LS-Druckleitung 55 über den Drosselschieber 48 und den Steuerschieber 25 zum Rücklauf, wobei der Steuerschieber 25 selbst als Vollschieber ausgebildet ist, stellt eine besonders vorteilhafte Kombination dar.The formation of the control device 10 with one of the Measuring orifice 22 connected downstream on the control slide 25 Pressure compensator 12, with the one separated from the pressure compensator 12 Check valve 42 and with the relief of the LS pressure line 55 via the throttle valve 48 and the Control spool 25 for returning, the control spool 25 is designed as a full slide valve particularly advantageous combination.

Selbstverständlich sind an der gezeigten Ausführungsform Änderungen im Rahmen des Schutzbegehrens möglich.Of course, are shown on the embodiment Changes within the scope of the protection request are possible.

Claims (12)

  1. Hydraulic control device for the load-pressure-independent control of a double-acting engine, with a directional valve (10), the housing (13) of which receives in a longitudinal bore (14) a control slide (25) which has piston portions which serve for controlling the speed and direction of the engine and of which the piston portion serving as a measuring diaphragm (22) for the speed control, on the control slide, is connected via a housing-side transverse duct (62) to the piston portions (27-29), arranged separately from the said piston portion, for direction control, on the control slide (25), this transverse duct (62) having inserted in it a two-way pressure balance (12) which controls the volume flow and the throttle slide (48) of which is acted upon in the closing direction by a spring (52) and a maximum load pressure and in the opening direction by the pressure in the transverse duct (62), downstream of the measuring diaphragm (22) and upstream of the pressure balance (12), and with a pressure pick-up orifice (55) for a control circuit, the said pressure pick-up orifice lying downstream of the throttle slide (48), in the transverse duct (62), and being capable of being relieved to a return chamber (19) via a relief device on the control slide, characterized in that a non-return valve (42) separate from the throttle slide (48) is inserted into the transverse duct (62), downstream of the pressure balance (12) and upstream of the control slide (25), in that the pressure pick-up orifice (55) lies upstream of the non-return valve (42), in that the relief device has, on the control slide (25) , a piston portion (30) which controls the connection between an outflow-side measuring-diaphragm chamber (20) and the adjacent return chamber (19), and in that the throttle slide (48), in its initial position (74), makes a throttled connection (51, 49) between the pressure pick-up orifice (55) and this measuring-diaphragm chamber (20) and, in its working positions (75), shuts off this connection (51, 49).
  2. Hydraulic control device according to Claim 1, characterized in that a second individual measuring diaphragm (44), which, in particular, is designed to be adjustable, is inserted into the transverse duct (62), downstream of the measuring diaphragm (22) and upstream of the pressure balance (20).
  3. Hydraulic control device according to Claim 1 or 2, characterized in that the control slide (25) has, in additon to a neutral position (34) and two working positions (35, 36), a fourth switching position (37) for free motion.
  4. Hydraulic control device according to one of Claims 1 to 3, characterized in that the control slide (25) is designed as a solid slide without connecting lines for working or control-pressure media inside it.
  5. Hydraulic control device according to one of Claims 2 to 4, characterized in that the housing (13) has two bores (39, 41) which run parallel to the longitudinal bore (14) for the control slide (25) and which all lie in one plane and of which the second, middle bore (39) receives the non-return valve (42), whilst the pressure balance (12) and the individual measuring diaphragm (44) are arranged in the other, third bore (41).
  6. Hydraulic control device according to Claim 5, characterized in that the middle bore (39) is designed in a manner of a blind hole and projects with its inner end into a circulation chamber (46) which runs perpendicularly to the longitudinal axis of the control slide (25) and which passes through the third bore (41).
  7. Hydraulic control device according to Claim 6, characterized in that the measuring-diaphragm chamber (20) lying downstream has a prolongation (45) which extends perpendicularly to the control slide (25) and which runs essentially parallel to the circulation chamber (46) and passes through the third bore (41), whilst the measuring-diaphragm chamber (21) lying upstream is connected to an inflow duct (61).
  8. Hydraulic control device according to one of Claims 1 to 7, characterized in that the measuring-diaphragm chambers (20, 21) assigned to the measuring diaphragm (22) are arranged in the longitudinal bore (14) laterally next to the five working chambers (15 to 19) for direction control in the housing (13).
  9. Hydraulic control device according to one of Claims 1 to 8, characterized in that the throttle slide (48) is designed as a hollow slide with a blind-hole bore (49) and, for controlling the relief of the pressure pick-up orifice (55), has a radial bore (51) capable of being overlapped as a function of position.
  10. Hydraulic control device according to one of Claims 6 to 9, characterized in that the wall lying in the housing (13) between the circulation chamber (46) and the outflow-side measuring-diaphragm chamber (20), in the third bore (41), forms an annular web (47) which forms the housing-side control edges for the throttle slide (48) and for the individual measuring diaphragm (44).
  11. Hydraulic control device according to Claim 10, characterized in that the annular web (47) lies approximately the same radial plane as the relief-controlling piston portion (30) on the control slide (25) in its neutral position (34).
  12. Hydraulic control device according to one of Claims 1 to 11, characterized in that the throttle slide (48) has, between its initial position (74) and its working positions (75), a shut-off position (76), in which the throttled connection (51) is closed and the transverse duct (62) is not yet opened.
EP98102270A 1997-05-07 1998-02-10 Hydraulic control device for the load-independent control of a double acting actuator Expired - Lifetime EP0877169B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19719228 1997-05-07
DE19719228A DE19719228A1 (en) 1997-05-07 1997-05-07 Hydraulic control device for load-independent control of a double-acting engine

Publications (3)

Publication Number Publication Date
EP0877169A2 EP0877169A2 (en) 1998-11-11
EP0877169A3 EP0877169A3 (en) 2000-01-19
EP0877169B1 true EP0877169B1 (en) 2003-12-03

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP98102270A Expired - Lifetime EP0877169B1 (en) 1997-05-07 1998-02-10 Hydraulic control device for the load-independent control of a double acting actuator

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EP (1) EP0877169B1 (en)
DE (2) DE19719228A1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10027382A1 (en) 2000-06-02 2001-12-06 Bosch Gmbh Robert Hydraulic control device
US6318079B1 (en) * 2000-08-08 2001-11-20 Husco International, Inc. Hydraulic control valve system with pressure compensated flow control
CN109798270B (en) * 2019-02-25 2020-05-19 哈尔滨工业大学 Multi-mode energy-saving servo actuator and method for realizing multi-mode energy saving

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3629850A1 (en) * 1986-09-02 1988-03-03 Bosch Gmbh Robert Hydraulic directional control valve
DE3634728A1 (en) * 1986-10-11 1988-04-21 Rexroth Mannesmann Gmbh VALVE ARRANGEMENT FOR LOAD-INDEPENDENT CONTROL OF SEVERAL SIMPLY ACTUATED HYDRAULIC CONSUMERS
DE4026720A1 (en) * 1989-12-19 1991-06-20 Bosch Gmbh Robert Hydraulic directional control valve for load sensing - incorporates extra chamber to allow left or right hand installation
DE4136991C2 (en) * 1991-11-11 2000-11-02 Bosch Gmbh Robert Hydraulic directional valve
EP0684389B1 (en) * 1991-12-25 1999-09-08 Kayaba Industry Co., Ltd. Control device for multiple hydraulic apparatus

Also Published As

Publication number Publication date
DE19719228A1 (en) 1998-11-12
DE59810308D1 (en) 2004-01-15
EP0877169A3 (en) 2000-01-19
EP0877169A2 (en) 1998-11-11

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