EP1184576B1 - Valve system - Google Patents

Valve system Download PDF

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Publication number
EP1184576B1
EP1184576B1 EP01112733A EP01112733A EP1184576B1 EP 1184576 B1 EP1184576 B1 EP 1184576B1 EP 01112733 A EP01112733 A EP 01112733A EP 01112733 A EP01112733 A EP 01112733A EP 1184576 B1 EP1184576 B1 EP 1184576B1
Authority
EP
European Patent Office
Prior art keywords
pressure
control
connection
control piston
piston
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
EP01112733A
Other languages
German (de)
French (fr)
Other versions
EP1184576A1 (en
Inventor
Peter BÜTTNER
Tatu Miikkulainen
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
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Publication date
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Publication of EP1184576A1 publication Critical patent/EP1184576A1/en
Application granted granted Critical
Publication of EP1184576B1 publication Critical patent/EP1184576B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
    • F15B11/028—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the actuating force
    • 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
    • F15B13/0401—Valve members; Fluid interconnections therefor
    • F15B13/0402—Valve members; Fluid interconnections therefor for linearly sliding valves, e.g. spool 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
    • 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
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
    • F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
    • F15B13/0416—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor with means or adapted for load sensing
    • F15B13/0417—Load sensing elements; Internal fluid connections therefor; Anti-saturation or pressure-compensation valves
    • F15B13/0418—Load sensing elements sliding within a hollow main valve spool
    • 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
    • F15B13/042—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure
    • 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
    • F15B2211/30535—In combination with a pressure compensating valve the pressure compensating valve is arranged between pressure source and 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
    • F15B2211/315—Directional control characterised by the connections of the valve or valves in the circuit
    • F15B2211/3157—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source, an output member and a return line
    • F15B2211/31576—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source, an output member and a return line having a single pressure source and a single output member
    • 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
    • F15B2211/32—Directional control characterised by the type of actuation
    • F15B2211/329—Directional control characterised by the type of actuation actuated by fluid pressure
    • 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
    • F15B2211/705—Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
    • F15B2211/7051—Linear output members
    • F15B2211/7053—Double-acting output members
    • 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
    • F15B2211/76—Control of force or torque of the output member

Definitions

  • the invention relates to a valve device for driving a consumer according to the preamble of the claim 1.
  • Such Directional control valves have a control piston, which can be moved axially is guided in a housing and over the two with the tool - for example, a hydraulic cylinder for pressurizing a feed roller, for actuation a knife or to control the force of a saw blade - connected working connections with a to a hydraulic pump connected pressure connection or a tank connection are connectable.
  • the end faces of the control piston are acted upon by a control pressure, so that the control piston from a home position to a control position for connection a working connection with the pressure connection and the other working port with the tank port slidably is.
  • the effective load pressure at the respective consumer becomes two via inner holes of the spool Led volumetric flask, which in each case an end portion of the Control piston are stored. Become by this load pressure the two volumetric flasks are preloaded. At a deflection of the Control piston runs one of the volumetric flask with its free End section on a stop, so that an am Control piston in the closing direction effective reaction force resulting from the cross-sectional area of the volumetric flask and determined by consumer pressure.
  • the invention is based on the object to develop the valve device such that a Pressure limitation of the load pressure applied to the load in a compact design and low technical device Effort is possible.
  • a control piston of the valve device can be when a limit load pressure in one Bring pressure limiting position, in which the Load pressure leading consumer outlet with one Tank connection is connected and the load pressure at this Consumer connection continues in the closing direction on the Control piston acts.
  • the pressure on the Consumer terminal be reduced, the Limit load pressure by selection of the control pressure or the Magnetic force for axial displacement of the control piston is variable.
  • the load pressure is released via an opening in an axial bore Radial bore of the control piston tapped at the work connection.
  • the valve device according to the invention is special compact design when the control piston with a collar is executed, the peripheral edges as control edges for the admission or admission of a pressure connection associated Control room and a tank connection assigned Serve control room. In this tax code also opens the Radial bore, via which the load pressure at the consumer connection is tapped.
  • the distance of the radial bore to the tank control room auf josnden control edge is preferably lower as the width of the control room assigned to the work connection chosen, so that in the mentioned control position the working connection is connected to the tank connection and at the same time the load pressure is tapped via the radial bore can be.
  • the control piston is preferably with another Ring collar executed, over which the pressure fluid flow to another work connection is controllable.
  • the guided in the axial bore of the control piston Load pressure is tapped via a load signaling line and led to a control device of a pump.
  • the control piston can be provided with two volumetric flasks, so that the individual pressure on both working connections can be limited is.
  • valve device according to the invention can particularly advantageous for the operation of tools a Harvesterkopfs be used.
  • the deflection of the control piston can either via a suitable control pressure difference or via electromagnets respectively.
  • FIG. 1 shows a circuit diagram of an inventive Valve device 1, with the functions of a proportional Directional valve and a proportional pressure valve for Control of a consumer, in the present case one not shown Harvesterkopfes are realized.
  • the Valve device 1 has a dot-dash line indicated Proportional valve 2, via which a consumer 4 with a Hydraulic pump 6 and a tank T is connectable.
  • the hydraulic pump 6 is Constant pump 8 with inlet pressure compensator 10 executed.
  • alternative could also be a variable pump for pressure medium supply be used with a pump regulator.
  • the pressure medium is by means of the hydraulic pump 6 to a Pressure port P of the proportional valve 2 out, wherein the consumer via a working connection A or a second working port B supplied with the pressure medium becomes.
  • the pressure flowing back from the consumer pressure medium is via the other working connection B or A and a tank connection S returned to the tank T.
  • the consumer 4 for example, designed as a hydraulic cylinder, about the contact pressure of a feed roller of the harvester head is adjustable.
  • control piston 14 In the housing 12 of the proportional valve 2 is an axial bore formed, in which a control piston 14 axially displaceable is guided.
  • the control piston 14 has two each a working connection A, B associated annular collars 16, 18, which are spaced apart by a central web 20.
  • the end faces 22, 24 of the control piston 14 are with not shown Compressed springs acted, so that the control piston 14 biased in its basic position shown in Figure 1 is.
  • the control piston 14 is dashed from one indicated, unilaterally closed axial bore 26th interspersed, which in the left in Figure 1 End face 22 of the control piston 14 opens.
  • In the peripheral surface of the two annular collars 16, 18 are respectively one or more radial bores 28, 30 are formed, the in the axial bore 26 open.
  • the axial bore 26 has in the region of End face 22 a Volumetric flask 32, its distal portion in the axial direction protruding from the control piston 14.
  • the housing has 2 two connected to the tank port S tank spaces 36, 38.
  • a first Control chamber 40 and a second control chamber 42 is formed, while in the region of the central web 20, a pressure control room 44 is provided.
  • the frontal peripheral edges of the two annular collars 16, 18 are as control edges with one or more Fine control notches 46, 48, 50, 52 distributed on the circumference formed, of which in Figure 1 by way of example only one of the notches is shown.
  • the two radial bores 28, 30 are shown in the Basic position of the peripheral walls between the spaces 40, 44 and 44, 42 covered and thus circumferentially locked.
  • the control of the control piston 14 can either hydraulically by applying a control pressure in frontal Control spaces 60, 62 or via solenoid valves, whose Tappet act on the end faces of the control piston 14.
  • the in the axial bore 26 prevailing pressure via an LS channel 64 tapped and via a control connection LS to the inlet pressure compensator 10 guided so that, depending on the in the axial bore 26 prevailing load pressure, the pressure medium supply to the proportional valve 2 via the hydraulic pump. 6 is adjustable.
  • Figure 2 shows various axial positions of the control piston 14 of the proportional valve 2.
  • the shown in Figure 2a Basic position corresponds to that shown in Figure 1 spring-biased center position of the control piston 14, in which the control chamber 40 is connected to the tank space 36 is while the rooms 40, 44, 42 no connection have one another.
  • Control pressure or the force of the electromagnet on the one hand and of the load pressure at the consumer 4 and the force of in Closing direction acting - not shown compression spring - adjusts itself an equilibrium position, which is suitable Choice of area ratios 14, 21 as well as the power of Compression spring of the working position shown in Figure 2b corresponds, in which the feed roller with a predetermined pressure is biased against the log pile.
  • this Pressure limiting position is the radial bore 28 just opened, and the connection between the first control room 40 and the adjacent one Tank space 36 via the fine control notches 52 is turned on, so that pressure medium from the cylinder chamber 54 via the Working port A, the control chamber 40, the fine control notches 52, the tank space 36 and the tank port S to the tank T out can flow out.
  • the pressure in the cylinder chamber 54 can be thereby limit to a predetermined maximum pressure, the depending on the control pressure and the diameter of the in the pressure limiting position still controlled measuring piston 32 is adjustable.
  • this Pressure limiting position is still the connection between the second control chamber 42 and the tank space 38 open, so that the pressure medium from the annular space 56 for Tank T can flow out.
  • the radial bore 28 is closed, while the radial bore 30 with respect to the second Control chamber 42 is open, so that the working connection B prevailing load pressure on the radial bore 30th and the axial bore 26 is fed into the LS channel 64.
  • the hydraulic cylinder is retracted and the feed rollers moved away from the trunk.
  • valve device can be the compressive force as a function of the diameter of the trunk and from the working phase (sawing, feed etc.) reliable hold in the optimal areas, leaving an overload the Harvesterkopfes is practically impossible.
  • a valve device for driving a consumer in particular a tool of a Harvesterkopfes, in which a control piston for controlling the Pressure medium paths between a hydraulic pump and the consumer is provided.
  • the load pressure acting on the consumer acts on exceeding a limit load pressure in Closing direction on the control piston, this in a Pressure limiting position is movable, in which the Pressure on the consumer is degradable down to a tank and the at the consumer effective load pressure on acts in the closing direction.

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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)

Description

Die Erfindung betrifft eine Ventileinrichtung zur Ansteuerung eines Verbrauchers gemäß dem Oberbegriff des Patentanspruchs 1.The invention relates to a valve device for driving a consumer according to the preamble of the claim 1.

In der Forstwirtschaft besteht eine Tendenz dahingehend, die teuere Handarbeit durch Maschinenarbeit zu ersetzen. Dabei werden Maschinenaggregate eingesetzt, die mehrere Teilarbeiten der Holzernte, wie beispielsweise Fällen, Entasten, Entrinden, Sammeln, Ablegen ausführen können. Sogenannte Vollernter (Harvester) werden verwendet, um die Hölzer vom Stock zu trennen, zu entasten, einzuschneiden und die abgelängten Hölzer zu sammeln. Die weitere Verarbeitung erfolgt dann über sogenannte Processoren, die weitere Teilarbeiten übernehmen. Die genannten Fällungsmaschinen sind in der Regel auf einem geländegängigen Arbeitsgerät befestigt und haben einen Hydraulikarm an dem ein die Bearbeitungswerkzeuge, beispielsweise Greifer, Vorschubwalzen, Sägen tragender Bearbeitungskopf (hydraulisch angesteuerter Harvesterkopf) angeordnet ist.There is a tendency in forestry to to replace the expensive handwork by machine work. This machine aggregates are used, the more Partial work of harvesting, such as felling, Deleting, debarking, collecting, dropping can be performed. So-called Harvesters are used to harvest the crop Separate the wood from the stick, to strain it, to cut it and to collect the cut timbers. The others Processing then takes place via so-called processors, which take over additional work. The mentioned Felling machines are usually on an off-road Attached equipment and have a hydraulic arm on one the processing tools, such as grippers, Feed rollers, saw-bearing machining head (hydraulically driven harvester head) is arranged.

Die hydraulische Betätigung der Werkzeuge erfolgt über im Harvesterkopf aufgenommene Wegeventile, wie sie beispielsweise in der WO 98/05870 A1 beschrieben sind. Derartige Wegeventile haben einen Steuerkolben, der axial verschiebbar in einem Gehäuse geführt ist und über den zwei mit dem Werkzeug - beispielsweise einem Hydraulikzylinder zur Druckbeaufschlagung einer Vorschubwalze, zur Betätigung eines Messers oder zur Kraftsteuerung eines Sägeblattes - verbundene Arbeitsanschlüsse mit einem an eine Hydraulikpumpe angeschlossenen Druckanschluß oder einen Tankanschluß verbindbar sind. Die Stirnflächen des Steuerkolbens sind mit einem Steuerdruck beaufschlagbar, so daß der Steuerkolben aus einer Grundposition in eine Steuerposition zur Verbindung eines Arbeitsanschlusses mit dem Druckanschluß und des anderen Arbeitsanschlusses mit dem Tankanschluß verschiebbar ist. Der am jeweiligen Verbraucher wirksame Lastdruck wird über Innenbohrungen des Steuerkolbens zu zwei Meßkolben geführt, die in jeweils einem Endabschnitt des Steuerkolbens gelagert sind. Durch diesen Lastdruck werden die beiden Meßkolben vorgespannt. Bei einer Auslenkung des Steuerkolbens läuft einer der Meßkolben mit seinem freien Endabschnitt auf einen Anschlag auf, so daß sich eine am Steuerkolben in Schließrichtung wirksame Reaktionskraft ergibt, die von der Querschnittsfläche des Meßkolbens und vom Verbraucherdruck bestimmt ist.The hydraulic actuation of the tools via in the Harvesterkopf recorded way valves, as for example in WO 98/05870 A1 are described. such Directional control valves have a control piston, which can be moved axially is guided in a housing and over the two with the tool - for example, a hydraulic cylinder for pressurizing a feed roller, for actuation a knife or to control the force of a saw blade - connected working connections with a to a hydraulic pump connected pressure connection or a tank connection are connectable. The end faces of the control piston are acted upon by a control pressure, so that the control piston from a home position to a control position for connection a working connection with the pressure connection and the other working port with the tank port slidably is. The effective load pressure at the respective consumer becomes two via inner holes of the spool Led volumetric flask, which in each case an end portion of the Control piston are stored. Become by this load pressure the two volumetric flasks are preloaded. At a deflection of the Control piston runs one of the volumetric flask with its free End section on a stop, so that an am Control piston in the closing direction effective reaction force resulting from the cross-sectional area of the volumetric flask and determined by consumer pressure.

Problematisch bei derartigen Lösungen ist, daß die von den Werkzeugen aufgebrachte Druckkraft, beispielsweise der Anpreßdruck der Vorschubwalzen oder die von den Greifern aufgebrachte Kraft in Abhängigkeit vom Durchmesser des Stammes eingestellt werden muß. Bei dem vorbeschriebenen Wegeventil ist eine derartige Individualdruckbegrenzung nicht möglich, da über den Steuerkolben beim Ansteigen des Druckes am Verbraucher lediglich die Druckmittelzufuhr zum Verbraucher abgesperrt wird. Dadurch kann es beispielsweise bei einer Baumschälmaschine zu Druckspitzen kommen, wenn die Vorschubwalze einen Ast oder einen ähnlichen Vorsprung des Baumstammes überfährt, so daß eine Schädigung der Walzen oder der sonstigen Werkzeuge nicht ausgeschlossen ist. The problem with such solutions is that of the tools applied compressive force, for example, the Contact pressure of the feed rollers or the grippers applied force depending on the diameter of the Stammes must be adjusted. In the above Directional control valve is such an individual pressure limitation not possible because of the control piston when rising the Pressure on the consumer only the pressure medium supply to Consumer is shut off. This can for example in a tree peeling machine come to pressure peaks when the feed roller a branch or a similar projection the tree trunk passes over, so that damage to the rollers or other tools is not excluded.

In der DE 197 49 639 A1 der Anmelderin wird eine Ventileinrichtung zur Individualdruckbegrenzung offenbart, bei der einem die Verbraucheransteuerung realisierenden Proportionalventil ein Vergleichsventil zugeordnet ist, über das die am Proportionalventil wirksame Steuerdruckdifferenz regelbar ist. Eine derartige Ventilanordnung löst zwar das vorbeschriebene funktionale Problem, die bekannte Ventileinrichtung ist jedoch sehr teuer und wartungsanfällig und erfordert einen hohen Platzbedarf, so daß ein Einsatz bei Harvesterköpfen ausscheidet.In DE 197 49 639 A1 of the Applicant is a valve device for individual pressure limitation disclosed in the one the consumer control realizing proportional valve a comparison valve is assigned over the the effective on the proportional valve control pressure difference adjustable is. Although such a valve arrangement solves the above-described functional problem, the known valve device is however very expensive and maintenance-prone and requires a lot of space, so that a use in Harvester heads excreted.

In der US 5,284,220 ist ein elektromagnetisches Druckbegrenzungsventil mit zwei Arbeitsanschlüssen offenbart, bei dem bei einer Verschiebung eines Steuerkolbens aus seiner Grundstellung der Druck in dem einen Arbeitsanschluß fällt und der Druck in dem anderen Arbeitsanschluß entsprechend steigt.In US 5,284,220 is an electromagnetic Pressure relief valve with two working connections disclosed in which a displacement of a Control piston from its basic position the pressure in the one working connection falls and the pressure in the other Work connection increases accordingly.

Demgegenüber liegt der Erfindung die Aufgabe zugrunde, die Ventileinrichtung derart weiterzubilden, daß eine Druckbegrenzung des am Verbraucher anliegenden Lastdrucks bei kompakter Ausführung und geringem vorrichtungstechnischen Aufwand möglich ist.In contrast, the invention is based on the object to develop the valve device such that a Pressure limitation of the load pressure applied to the load in a compact design and low technical device Effort is possible.

Diese Aufgabe wird durch die Merkmale des Patentanspruchs 1 gelöst.This object is achieved by the features of the claim 1 solved.

Erfindungsgemäß läßt sich ein Steuerkolben der Ventileinrichtung bei Überschreiten eines Grenz-Lastdrucks in eine Druckbegrenzungsposition bringen, in der der den Lastdruck führende Verbraucheranschluß mit einem Tankanschluß verbunden ist und der Lastdruck an diesem Verbraucheranschluß weiterhin in Schließrichtung auf den Steuerkolben wirkt. Auf diese Weise kann der Druck am Verbraucheranschluß abgebaut werden, wobei der Grenzlastdruck durch Wahl des Steuerdrucks oder der Magnetkraft zur Axialverschiebung des Steuerkolbens variierbar ist. Durch diese Individualdruckbegrenzung kann eine Beschädigung des Verbrauchers durch Druckspitzen zuverlässig vermieden werden. Ein weiterer Vorteil der erfindungsgemäßen Lösung liegt darin, daß die Druckregelung und die Wegeventilfunktion durch einen einzigen Steuerkolben realisiert sind, während bei der eingangs beschriebenen Lösung gemäß der DE 197 49 639 A1 zusätzliche kostspielige Ventileinrichtungen zur Begrenzung des Maximaldruckes erforderlich sind.According to the invention, a control piston of the valve device can be when a limit load pressure in one Bring pressure limiting position, in which the Load pressure leading consumer outlet with one Tank connection is connected and the load pressure at this Consumer connection continues in the closing direction on the Control piston acts. In this way, the pressure on the Consumer terminal be reduced, the Limit load pressure by selection of the control pressure or the Magnetic force for axial displacement of the control piston is variable. By this individual pressure limitation can Damage to the consumer due to pressure peaks reliably avoided. Another advantage of inventive solution lies in the fact that the pressure control and the way valve function by a single Control pistons are realized while at the entrance described solution according to DE 197 49 639 A1 additional expensive valve equipment to limit the maximum pressure required are.

Die Beaufschlagung der Stirnflächen des Steuerkolbens mit dem Lastdruck erfolgt über einen Meßkolben, der - ähnlich wie bei der WO 98/05870 A1 - in einem Endabschnitt des Steuerkolbens geführt ist, der vom Lastdruck vorgespannt ist und dessen freier Endabschnitt bei Auslenkung des Steuerkolbens gegen einen Anschlag bewegbar ist.The application of the end faces of the control piston with the load pressure via a volumetric flask, which - similar as in WO 98/05870 A1 - in an end section of Control piston is guided by the load pressure is biased and its free end portion upon deflection of the control piston against a stop is movable.

Bei einem besonders bevorzugten Ausführungsbeispiel wird der Lastdruck über eine in einer Axialbohrung mündende Radialbohrung des Steuerkolbens am Arbeitsanschluß abgegriffen.In a particularly preferred embodiment the load pressure is released via an opening in an axial bore Radial bore of the control piston tapped at the work connection.

Die erfindungsgemäße Ventileinrichtung ist besonders kompakt ausgebildet, wenn der Steuerkolben mit einem Ringbund ausgeführt ist, dessen Umfangskanten als Steuerkanten zur Auf- bzw. Zusteuerung eines dem Druckanschluß zugeordneten Steuerraums und eines dem Tankanschluß zugeordneten Steuerraums dienen. In diesem Steuerbund mündet auch die Radialbohrung, über die der Lastdruck am Verbraucheranschluß abgegriffen wird.The valve device according to the invention is special compact design when the control piston with a collar is executed, the peripheral edges as control edges for the admission or admission of a pressure connection associated Control room and a tank connection assigned Serve control room. In this tax code also opens the Radial bore, via which the load pressure at the consumer connection is tapped.

Der Abstand der Radialbohrung zu der den Tank-Steuerraum aufsteuernden Steuerkante wird vorzugweise geringer als die Breite des dem Arbeitsanschluß zugeordneten Steuerraumes gewählt, so daß in der angesprochenen Steuerposition der Arbeitsanschluß mit dem Tankanschluß verbunden ist und gleichzeitig der Lastdruck über die Radialbohrung abgegriffen werden kann.The distance of the radial bore to the tank control room aufsteuernden control edge is preferably lower as the width of the control room assigned to the work connection chosen, so that in the mentioned control position the working connection is connected to the tank connection and at the same time the load pressure is tapped via the radial bore can be.

Der Steuerkolben wird vorzugsweise mit einem weiteren Ringbund ausgeführt, über den die Druckmittelströmung zu einem weiteren Arbeitsanschluß steuerbar ist.The control piston is preferably with another Ring collar executed, over which the pressure fluid flow to another work connection is controllable.

Der in der Axialbohrung des Steuerkolbens geführte Lastdruck wird über eine Lastmeldeleitung abgegriffen und an eine Regeleinrichtung einer Pumpe geführt.The guided in the axial bore of the control piston Load pressure is tapped via a load signaling line and led to a control device of a pump.

Der Steuerkolben kann mit zwei Meßkolben versehen sein, so daß der Individualdruck an beiden Arbeitsanschlüssen begrenzbar ist.The control piston can be provided with two volumetric flasks, so that the individual pressure on both working connections can be limited is.

Wie eingangs erwähnt, kann die erfindungsgemäß Ventileinrichtung besonders vorteilhaft zur Betätigung von Werkzeugen eines Harvesterkopfs eingesetzt werden.As mentioned at the beginning, the valve device according to the invention can particularly advantageous for the operation of tools a Harvesterkopfs be used.

Die Auslenkung des Steuerkolbens kann entweder über eine geeignete Steuerdruckdifferenz oder über Elektromagnete erfolgen.The deflection of the control piston can either via a suitable control pressure difference or via electromagnets respectively.

Sonstige vorteilhafte Weiterbildungen der Erfindung sind Gegenstand der weiteren Unteransprüche.Other advantageous developments of the invention are the subject of the further subclaims.

Im folgenden wird ein bevorzugtes Ausführungsbeispiel der Erfindung anhand schematischer Zeichnungen näher erläutert. Es zeigen:

  • Figur 1 eine schematisierte Ansicht einer erfindungsgemäßen Ventileinrichtung zur Ansteuerung eines Verbrauchers und
  • Figuren 2a bis 2e verschiedene Stellungen eines Steuerkolbens der Ventileinrichtung aus Figur 1.
    • In the following a preferred embodiment of the invention will be explained in more detail with reference to schematic drawings. Show it:
  • Figure 1 is a schematic view of a valve device according to the invention for controlling a consumer and
  • 2a to 2e different positions of a control piston of the valve device of Figure 1.

    • Figur 1 zeigt ein Schaltschema einer erfindungsgemäßen Ventileinrichtung 1, mit der Funktionen eines proportionalen Wegeventils und eines proportionalen Druckventils zur Ansteuerung eines Verbrauchers, im vorliegenden Fall eines nicht dargestellten Harvesterkopfes realisiert sind. Die Ventileinrichtung 1 hat ein strichpunktiert angedeutetes Proportionalventil 2, über das ein Verbraucher 4 mit einer Hydropumpe 6 und einem Tank T verbindbar ist. Bei dem dargestellten Ausführungsbeispiel ist die Hydropumpe 6 als Konstantpumpe 8 mit Eingangsdruckwaage 10 ausgeführt. Alternativ könnte zur Druckmittelversorgung auch eine Verstellpumpe mit einem Pumpenregler verwendet werden.Figure 1 shows a circuit diagram of an inventive Valve device 1, with the functions of a proportional Directional valve and a proportional pressure valve for Control of a consumer, in the present case one not shown Harvesterkopfes are realized. The Valve device 1 has a dot-dash line indicated Proportional valve 2, via which a consumer 4 with a Hydraulic pump 6 and a tank T is connectable. In the illustrated Embodiment is the hydraulic pump 6 as Constant pump 8 with inlet pressure compensator 10 executed. alternative could also be a variable pump for pressure medium supply be used with a pump regulator.

    Das Druckmittel wird mittels der Hydropumpe 6 zu einem Druckanschluß P des Proportionalventils 2 geführt, wobei der Verbraucher über einen Arbeitsanschluß A oder einen zweiten Arbeitsanschluß B mit dem Druckmittel versorgt wird. Das vom Verbraucher zurückströmende Druckmittel wird über den anderen Arbeitsanschluß B bzw. A und einen Tankanschluß S zum Tank T zurückgeleitet.The pressure medium is by means of the hydraulic pump 6 to a Pressure port P of the proportional valve 2 out, wherein the consumer via a working connection A or a second working port B supplied with the pressure medium becomes. The pressure flowing back from the consumer pressure medium is via the other working connection B or A and a tank connection S returned to the tank T.

    Bei dem dargestellten Ausführungsbeispiel ist der Verbraucher 4 beispielsweise als Hydrozylinder ausgeführt, über den der Anpreßdruck einer Vorschubwalze des Harvesterkopfes einstellbar ist.In the illustrated embodiment, the consumer 4, for example, designed as a hydraulic cylinder, about the contact pressure of a feed roller of the harvester head is adjustable.

    Im Gehäuse 12 des Proportionalventils 2 ist eine Axialbohrung ausgebildet, in der ein Steuerkolben 14 axial verschiebbar geführt ist. Der Steuerkolben 14 hat zwei jeweils einem Arbeitsanschluß A, B zugeordnete Ringbünde 16, 18, die durch einen Mittelsteg 20 voneinander beabstandet sind. Die Stirnflächen 22, 24 des Steuerkolbens 14 sind mit nicht dargestellten Druckfedern beaufschlagt, so daß der Steuerkolben 14 in seine in Figur 1 dargestellte Grundposition vorgespannt ist. Der Steuerkolben 14 wird von einer gestrichelt angedeuteten, einseitig geschlossenen Axialbohrung 26 durchsetzt, die in die in Figur 1 linken Stirnfläche 22 des Steuerkolbens 14 mündet. In der Umfangsfläche der beiden Ringbünde 16, 18 sind jeweils eine oder mehrere Radialbohrungen 28, 30 ausgebildet, die in der Axialbohrung 26 münden.In the housing 12 of the proportional valve 2 is an axial bore formed, in which a control piston 14 axially displaceable is guided. The control piston 14 has two each a working connection A, B associated annular collars 16, 18, which are spaced apart by a central web 20. The end faces 22, 24 of the control piston 14 are with not shown Compressed springs acted, so that the control piston 14 biased in its basic position shown in Figure 1 is. The control piston 14 is dashed from one indicated, unilaterally closed axial bore 26th interspersed, which in the left in Figure 1 End face 22 of the control piston 14 opens. In the peripheral surface of the two annular collars 16, 18 are respectively one or more radial bores 28, 30 are formed, the in the axial bore 26 open.

    Die Axialbohrung 26 hat im Bereich der Stirnfläche 22 einen Meßkolben 32, dessen entfernter Abschnitt in Axialrichtung aus dem Steuerkolben 14 herausragt.The axial bore 26 has in the region of End face 22 a Volumetric flask 32, its distal portion in the axial direction protruding from the control piston 14.

    In der in Figur 1 dargestellten Grundposition ist im Abstand zu dem freien Endabschnitt des Meßkolbens 32 ein gehäusefester Anschlag 34 ausgebildet. Hinsichtlich des konkreten Aufbaus des Meßkolbens 32 und des Ventilsitzes der Axialbohrung 26 sei beispielhaft auf die Offenbarung der eingangs genannten WO 98/05870 A1 verwiesen, bei der ebenfalls ein Meßkolben in einem Steuerkolben geführt ist.In the basic position shown in Figure 1 is in Distance to the free end portion of the measuring piston 32 a fixed housing stop 34 is formed. Regarding the concrete construction of the volumetric flask 32 and the valve seat the axial bore 26 is exemplary of the disclosure referenced WO 98/05870 A1, in which also a volumetric flask is guided in a control piston.

    Wie des weiteren Figur 1 entnehmbar ist, hat das Gehäuse 2 zwei mit dem Tankanschluß S verbundene Tankräume 36, 38. Im Bereich der beiden Ringbünde 16, 18 sind im Gehäuse 2 ein erster Steuerraum 40 bzw. ein zweiter Steuerraum 42 ausgebildet, während im Bereich des Mittelstegs 20 ein Drucksteuerraum 44 vorgesehen ist.As can further be seen in FIG. 1, the housing has 2 two connected to the tank port S tank spaces 36, 38. In the area the two annular collars 16, 18 are in the housing 2 a first Control chamber 40 and a second control chamber 42 is formed, while in the region of the central web 20, a pressure control room 44 is provided.

    Die stirnseitigen Umfangskanten der beiden Ringbünde 16, 18 sind als Steuerkanten mit jeweils einer oder mehreren am Umfang verteilten Feinsteuerkerben 46, 48, 50, 52 ausgebildet, von denen in Figur 1 beispielhaft jeweils nur eine der Kerben dargestellt ist. The frontal peripheral edges of the two annular collars 16, 18 are as control edges with one or more Fine control notches 46, 48, 50, 52 distributed on the circumference formed, of which in Figure 1 by way of example only one of the notches is shown.

    In der in Figur 1 dargestellten Grundposition ist über die an der linken Ringstirnfläche des Ringbundes 16 ausgebildeten Feinsteuerkerben 52 die Verbindung zwischen dem ersten Steuerraum 40 und dem Tankraum 36 aufgesteuert, so daß das Druckmittel aus einem Zylinderraum 54 des als Differentialzylinder ausgeführten Hydrozylinders 4 zum Tank T abströmen kann und die nicht dargestellte Vorschubwalze entlastet ist. Die Verbindung zwischen dem Drucksteuerraum 44 und den beiden benachbarten Steuerräumen 40, 42 ist abgesperrt. Entsprechend ist auch die Verbindung zwischen dem zweiten Steuerraum 42 und dem Tankraum 38 geschlossen, so daß ein Ringraum 56 des Verbrauchers sowohl zum Tankanschluß S als auch zum Druckanschluß P hin abgesperrt ist.In the basic position shown in Figure 1 is about formed on the left annular end face of the annular collar 16 Feinsteuerkerben 52 the connection between the opened first control chamber 40 and the tank space 36, so that the pressure medium from a cylinder space 54 of the differential cylinder executed hydraulic cylinder 4 to the tank T. can flow and the feed roller, not shown is relieved. The connection between the pressure control room 44 and the two adjacent control chambers 40, 42 is shut off. Accordingly, the connection between the second control chamber 42 and the tank space 38 is closed, so that an annular space 56 of the consumer both to the tank connection S as well as to the pressure port P is shut off.

    Die beiden Radialbohrungen 28, 30 sind in der dargestellten Grundposition von den Umfangswandungen zwischen den Räumen 40, 44 und 44, 42 überdeckt und somit umfangsseitig verschlossen.The two radial bores 28, 30 are shown in the Basic position of the peripheral walls between the spaces 40, 44 and 44, 42 covered and thus circumferentially locked.

    Die Ansteuerung des Steuerkolbens 14 kann entweder hydraulisch durch Anlegen eines Steuerdruckes in stirnseitige Steuerräume 60, 62 oder über Magnetventile erfolgen, deren Stößel die Stirnflächen des Steuerkolbens 14 beaufschlagen.The control of the control piston 14 can either hydraulically by applying a control pressure in frontal Control spaces 60, 62 or via solenoid valves, whose Tappet act on the end faces of the control piston 14.

    Wie in Figur 1 gestrichelt angedeutet ist, wird der in der Axialbohrung 26 herrschende Druck über einen LS-Kanal 64 abgegriffen und über einen Steueranschluß LS zu der Eingangsdruckwaage 10 geführt, so daß in Abhängigkeit von dem in der Axialbohrung 26 herrschenden Lastdruck die Druckmittelzufuhr zum Proportionalventil 2 über die Hydropumpe 6 einstellbar ist.As indicated by dashed lines in Figure 1, the in the axial bore 26 prevailing pressure via an LS channel 64 tapped and via a control connection LS to the inlet pressure compensator 10 guided so that, depending on the in the axial bore 26 prevailing load pressure, the pressure medium supply to the proportional valve 2 via the hydraulic pump. 6 is adjustable.

    Figur 2 zeigt verschiedene Axialpositionen des Steuerkolbens 14 des Proportionalventils 2. Die in Figur 2a dargestellte Grundposition entspricht der in Figur 1 dargestellten federvorgespannten Mittelstellung des Steuerkolbens 14, in der der Steuerraum 40 mit dem Tankraum 36 verbunden ist, während die Räume 40, 44, 42 keine Verbindung untereinander haben.Figure 2 shows various axial positions of the control piston 14 of the proportional valve 2. The shown in Figure 2a Basic position corresponds to that shown in Figure 1 spring-biased center position of the control piston 14, in which the control chamber 40 is connected to the tank space 36 is while the rooms 40, 44, 42 no connection have one another.

    Bei Beaufschlagung des in Figur 2 rechten Stirnflächenabschnittes 24 mit einem Steuerdruck oder der von einem Elektromagneten aufgebrachten Stellkraft wird der Steuerkolben 14 aus der in Figur 2a dargestellten Grundposition nach links bewegt. In der in Figur 2b dargestellten Arbeitsposition des Steuerkolbens 14 ist der erste Steuerraum 40 gegenüber dem Tankraum 36 und dem Drucksteuerraum 44 abgesperrt. Die Radialbohrung 28 wird durch die Steuerkante des ersten Steuerraums 40 aufgesteuert, so daß der am Arbeitsanschluß A herrschende Lastdruck, d. h. der Druck im Zylinderraum 54 in der Axialbohrung 26 und damit auch im LS-Kanal 64 anliegt. Der in der Axialbohrung 26 anstehende Lastdruck wirkt auf die Meßfläche des Meßkolbens 32 und drückt diesen gegen den Anschlag 34. Entsprechend beaufschlagt der Lastdruck eine Bodenfläche 21 des Steuerkolbens 14 in der Axialbohrung 26. Die Verbindung zwischen dem Drucksteuerraum 44 und dem zweiten Steuerraum 42 ist durch den Ringbund 18 geschlossen, während über die Steuerkerben 46 der Tankraum 38 mit dem zweiten Steuerraum 42 verbunden ist. D. h., in der in Fig. 2b dargestellten Gleichgewichtsposition erfolgt keine Druckmittelzufuhr über den Arbeitsanschluß A zum Verbraucher 54, während das Druckmittel im Ringraum 56 des Verbrauchers 4 über den Arbeitsanschluß B und den Tankanschluß S zum Tank T hin abströmen kann.Upon application of the right in Figure 2 end face portion 24 with a control pressure or that of one Solenoid applied force is the control piston 14 from the basic position shown in Figure 2a moved to the left. In the working position shown in Figure 2b of the control piston 14 is the first control room 40 shut off from the tank space 36 and the pressure control chamber 44. The radial bore 28 is through the control edge of the first control chamber 40 turned on, so that the working connection A prevailing load pressure, d. H. the pressure in the Cylinder space 54 in the axial bore 26 and thus also in LS channel 64 is present. The pending in the axial bore 26 Load pressure acts on the measuring surface of the measuring piston 32 and pushes it against the stop 34th Accordingly the load pressure acts on a bottom surface 21 of the Control piston 14 in the axial bore 26. The connection between the pressure control room 44 and the second control room 42 is closed by the annular collar 18, while on the Control notches 46 of the tank space 38 with the second control room 42 is connected. D. h., In the illustrated in Fig. 2b Balance position is no pressure medium over the working connection A to the consumer 54, while the Pressure medium in the annular space 56 of the consumer 4 via the Working connection B and the tank connection S to the tank T out can flow out.

    In Abhängigkeit von dem auf den Steuerkolben 14 wirkenden Steuerdruck bzw. der Kraft des Elektromagneten einerseits und von dem Lastdruck am Verbraucher 4 und der Kraft der in Schließrichtung wirkenden - nicht dargestellten Druckfeder - stellt sich eine Gleichgewichtsposition ein, die bei geeigneter Wahl der Flächenverhältnisse 14, 21 sowie der Kraft der Druckfeder der in Figur 2b dargestellten Arbeitsposition entspricht, in der die Vorschubwalze mit einem vorbestimmten Druck gegen den Baustamm vorgespannt ist.In Dependence on that acting on the control piston 14 Control pressure or the force of the electromagnet on the one hand and of the load pressure at the consumer 4 and the force of in Closing direction acting - not shown compression spring - adjusts itself an equilibrium position, which is suitable Choice of area ratios 14, 21 as well as the power of Compression spring of the working position shown in Figure 2b corresponds, in which the feed roller with a predetermined pressure is biased against the log pile.

    Beim Absinken des in Schließrichtung wirkenden Lastdruckes am Verbraucher 4 wird der Steuerkolben 14 aus der in Figur 2b dargestellten Arbeitsposition in die in Figur 2c bewegt, in der die Verbindung zwischen dem Drucksteuerraum 44 und dem ersten Steurerraum 40 über die Feinsteuerkerben 50 aufgesteuert ist. Des weiteren ist die Verbindung zwischen dem zweiten Steuerraum 42 und dem Tankraum 38 geöffnet. Das Druckmittel wird über den Arbeitsanschluß A in den Zylinderraum 54 geführt und das im Ringraum 56 vorhandene Druckmittel wird über den Arbeitsanschluß B und den Tankanschluß S zum Tank T zurückgeführt - der Hydrozylinder 4 wird ausgefahren und der Anpreßdruck der Vorschubwalzen erhöht.When lowering the load pressure acting in the closing direction on the consumer 4, the control piston 14 from the 2b in the working position shown in FIG 2c moves in which the connection between the pressure control room 44 and the first control room 40 on the Feinsteuerkerben 50 is turned on. Furthermore, the connection between the second control chamber 42 and the tank space 38 is opened. The pressure medium is via the working port A in guided the cylinder chamber 54 and existing in the annular space 56 Pressure medium is via the working port B and the Tank connection S returned to tank T - the hydraulic cylinder 4 is extended and the contact pressure of the feed rollers elevated.

    In dem Fall, in dem die Vorschubwalze einen Ast oder eine sonstige Radialverdickung des Stammes überfährt, wird die Vorschubwalze mit einer hohen Anpreßkraft beaufschlagt, so daß der Kolben des Hydrozylinders 4 in Einfahrrichtung beaufschlagt ist. Dies führt zu einer Druckerhöhung im Zylinderraum 54 und somit zu einer Erhöhung des am Arbeitsanschluß A anliegenden Lastdruckes. Dieser erhöhte Lastdruck wird über die gemäß Figur 2c aufgesteuerte Radialbohrung 28 zur Bodenfläche 21 geführt, so daß der Steuerkolben 14 durch den erhöhten Lastdruck aus der in den Figuren 2b und 2c dargestellten Positionen in Richtung zur Grundposition zurückbewegt wird. Der Steuerkolben 14 wird in Abhängigkeit von dem an der Bodenfläche 21 anliegenden erhöhten Lastdruck in eine Druckbegrenzungsposition gebracht, die in Figur 2d dargestellt ist. In dieser Druckbegrenzungsposition ist die Radialbohrung 28 gerade noch geöffnet, und die Verbindung zwischen dem ersten Steuerraum 40 und dem benachbarten Tankraum 36 über die Feinsteuerkerben 52 ist aufgesteuert, so daß Druckmittel aus dem Zylinderraum 54 über den Arbeitsanschluß A, den Steuerraum 40, die Feinsteuerkerben 52, den Tankraum 36 und den Tankanschluß S zum Tank T hin abströmen kann. Der Druck im Zylinderraum 54 läßt sich dadurch auf einen vorbestimmten Maximaldruck begrenzen, der in Abhängigkeit von dem Steuerdruck und dem Durchmesser des in der Druckbegrenzungsposition noch immer aufgesteuerten Meßkolben 32 einstellbar ist. In dieser Druckbegrenzungsposition ist weiterhin die Verbindung zwischen dem zweiten Steuerraum 42 und dem Tankraum 38 geöffnet, so daß das Druckmittel aus dem Ringraum 56 zum Tank T hin abströmen kann. Durch das Absinken des Lastdrucks am Arbeitsanschluß A verringert sich auch der auf die Bodenfläche 21 wirksame Druck, so daß der Steuerkolben 14 aus der in Figur 2d dargestellten Druckbegrenzungsposition in die Arbeitsposition gemäß Figur 2b zurückbewegt wird, in der die Verbindung des Zylinderraums 54 mit dem Tankanschluß S abgesperrt ist.In the case where the feed roller has a branch or another radial thickening of the trunk passes over the feed roller is subjected to a high contact pressure, so that the piston of the hydraulic cylinder 4 in the retraction direction is charged. This leads to an increase in pressure in the cylinder chamber 54 and thus to an increase in the work connection A applied load pressure. This increased load pressure is over the opened according to Figure 2c radial bore 28th to the bottom surface 21 guided, so that the control piston 14 by the increased load pressure from that in Figures 2b and 2c Positions shown towards the basic position is moved back. The control piston 14 is dependent from the voltage applied to the bottom surface 21 increased load pressure placed in a pressure limiting position, which is shown in Figure 2d. In this Pressure limiting position is the radial bore 28 just opened, and the connection between the first control room 40 and the adjacent one Tank space 36 via the fine control notches 52 is turned on, so that pressure medium from the cylinder chamber 54 via the Working port A, the control chamber 40, the fine control notches 52, the tank space 36 and the tank port S to the tank T out can flow out. The pressure in the cylinder chamber 54 can be thereby limit to a predetermined maximum pressure, the depending on the control pressure and the diameter of the in the pressure limiting position still controlled measuring piston 32 is adjustable. In this Pressure limiting position is still the connection between the second control chamber 42 and the tank space 38 open, so that the pressure medium from the annular space 56 for Tank T can flow out. Due to the sinking of the Load pressure at the working port A is also reduced on the bottom surface 21 effective pressure, so that the control piston 14 from the in FIG 2d illustrated pressure limiting position in the Working position is moved back according to Figure 2b, in the the connection of the cylinder chamber 54 with the tank port S. is locked.

    In der Druckbegrenzungsposition ist somit die Verbindung des ersten Steuerraums 40 zum Tankanschluß S und zur Axialbohrung 26 gleichzeitig geöffnet. Dies wird dadurch erreicht, daß der hydraulisch wirksame Abstand zwischen den Steuerkerben 52 und der in der Axialbohrung 26 mündenden Radialbohrung 28 geringer als die in Axialrichtung wirkensame Breite des ersten Steuerraums 40 gewählt ist.In the pressure limiting position is thus the Connection of the first control chamber 40 to the tank connection S and opened to the axial bore 26 simultaneously. this will achieved in that the hydraulically effective distance between the control notches 52 and in the axial bore 26th opening radial bore 28 less than the in Axially effective width of the first control chamber 40th is selected.

    Zum Abheben der Vorschubwalze vom Stamm wird die in Figur 2 linke Stirnfläche 22 des Steuerkolbens 14 mit einem Steuerdruck oder der Kraft eines Elektromagneten beaufschlagt, so daß der Steuerkolben 14 aus der Grundposition gemäß Figur 2a in die in Figur 2e dargestellte Position bewegt wird. Dabei ist der Steuerraum 40 über die Feinsteuerkerben 52 mit dem Tankraum 36 verbunden, während die Feinsteuerkerben 48 die Verbindung zwischen dem Drucksteuerraum 44 und dem zweiten Steuerraum 42 aufsteuern, so daß das Druckmittel über den Arbeitsanschluß B in den Ringraum 56 geführt wird und aus dem Zylinderraum 54 über den Arbeitsanschluß A zum Tank T zurückströmt. Bei der Axialverschiebung des Steuerkolbens 14 nach rechts zur Druckbeaufschlagung des Arbeitsanschlusses B ist die Radialbohrung 28 geschlossen, während die Radialbohrung 30 mit Bezug zum zweiten Steuerraum 42 geöffnet ist, so daß der am Arbeitsanschluß B herrschende Lastdruck über die Radialbohrung 30 und die Axialbohrung 26 in den LS-Kanal 64 eingspeist wird. Der Hydrozylinder wird eingefahren und die Vorschubwalzen vom Stamm wegbewegt.To lift the feed roller from the trunk is in FIG 2 left end face 22 of the control piston 14 with a Control pressure or the force of an electromagnet applied, so that the control piston 14 from the basic position moves according to Figure 2a in the position shown in Figure 2e becomes. In this case, the control chamber 40 via the fine control notches 52 connected to the tank space 36 while the fine control notches 48 the connection between the pressure control room 44 aufsteuern and the second control chamber 42, so that the Pressure fluid via the working port B in the annular space 56th is guided and out of the cylinder chamber 54 via the working connection A flows back to tank T. At the axial displacement of the control piston 14 to the right to pressurize the working port B, the radial bore 28 is closed, while the radial bore 30 with respect to the second Control chamber 42 is open, so that the working connection B prevailing load pressure on the radial bore 30th and the axial bore 26 is fed into the LS channel 64. The hydraulic cylinder is retracted and the feed rollers moved away from the trunk.

    Durch die erfindungsgemäße Ausgestaltung des Proportionalventils sind somit auf äußerst kompakte Weise zwei Grundfunktionen:

  • 1. die Funktion eines proportionalen Wegeventils und
  • 2. die Funktion eines proportionalen Druckregelventils
    • in einer einzigen, robusten und einfach aufgebauten Ventileinrichtung zusammengefaßt. Wie erwähnt, kann anstelle der Elektromagneten auch eine hydraulische Beaufschlagung oder ähnliches erfolgen. Die beiden vorgenannten Funktionen sind proportional ausgeführt, so daß eine exakte Steuerung des über den Verbraucher 4 betätigten Werkzeuges ermöglicht ist.Due to the inventive design of the proportional valve thus two basic functions are extremely compact manner:
  • 1. the function of a proportional directional valve and
  • 2. the function of a proportional pressure control valve
    • combined in a single, robust and simply constructed valve device. As mentioned, instead of the electromagnets, a hydraulic impingement or the like can take place. The two aforementioned functions are carried out proportionally, so that an exact control of the operated via the consumer 4 tool is possible.

    Mit der vorbeschriebenen Ventileinrichtung läßt sich die Druckkraft in Abhängigkeit vom Durchmesser des Stammes und von der Arbeitsphase (Sägen, Vorschub etc.) zuverlässig in den optimalen Bereichen halten, so daß eine Überlastung des Harvesterkopfes praktisch ausgeschlossen ist.With the above-described valve device can be the compressive force as a function of the diameter of the trunk and from the working phase (sawing, feed etc.) reliable hold in the optimal areas, leaving an overload the Harvesterkopfes is practically impossible.

    Offenbart ist eine Ventileinrichtung zur Ansteuerung eines Verbrauchers, insbesondere eines Werkzeuges eines Harvesterkopfes, bei dem ein Steuerkolben zur Steuerung der Druckmittelpfade zwischen einer Hydropumpe und dem Verbraucher vorgesehen ist. Der am Verbraucher wirkende Lastdruck wirkt bei Überschreiten eines Grenz-Lastdruckes in Schließrichtung auf den Steuerkolben, wobei dieser in eine Druckbegrenzungsposition bewegbar ist, in der der Druck am Verbraucher zu einem Tank hin abbaubar ist und der am Verbraucher wirksame Lastdruck weiter in Schließrichtung wirkt.Disclosed is a valve device for driving a consumer, in particular a tool of a Harvesterkopfes, in which a control piston for controlling the Pressure medium paths between a hydraulic pump and the consumer is provided. The load pressure acting on the consumer acts on exceeding a limit load pressure in Closing direction on the control piston, this in a Pressure limiting position is movable, in which the Pressure on the consumer is degradable down to a tank and the at the consumer effective load pressure on acts in the closing direction.

    Claims (6)

    1. Valve device for controlling a consumer (4), having a pressure connection (P), having at least one work connection (A, B), and having a tank connection (S) and a control piston (14) which can be moved, by an external force being applied, out of a resiliently centred initial position, in which the pressure connection (P) is blocked, into a work position, in which the pressure connection (P) is connected to the work connection (A) in order to supply pressure medium to the consumer (4),
      a measuring piston (32) which can be moved against a stop which is fixed to a housing being axially guided in the control piston (14), which measuring piston (32) can be subjected to the load pressure acting at the consumer (4) by means of a control line (26, 28, 30) in the control piston (14) so that, when a load pressure is reached which corresponds to the magnitude of the external force, the control piston (14) can be displaced in the direction of the initial position and the work connection (A) can be blocked in the direction towards the pressure connection (P),
      and the control line having an axial hole (26) and a radial hole (28) which opens therein and which is closed in the initial position and which is open in the operating position, characterised in that, in a pressure limitation function of the control piston (14) located between the operating position and the initial position, the pressure connection (P) is blocked and, when the radial hole (28) of the control line is open and the measuring piston (32) is supported on the stop (34), the work connection (A) is opened in a controlled manner relative to the tank connection (S).
    2. Valve device according to patent claim 1, the control piston (14) having an annular collar (16), one control edge (52) of which opens the connection relative to the tank connection (S) in a controlled manner and in which the radial hole (28) opens outwards, the hydraulically effective spacing between the control edge (52) and the radial hole (28) being smaller than the effective width of a control space (40) which is associated with the work connection (A).
    3. Valve device according to patent claim 1 or 2, having another work connection (B) which can be opened in a controlled manner via a second annular collar (18) of the control piston (14), the annular collar (18) having another radial hole (30) which opens in the axial hole (26) and by means of which the load pressure can be taken off when the work connection (B) is opened in a controlled manner.
    4. Valve device according to any one of the preceding patent claims, having a load indicator channel (64) which is connected, at one side, to an axial hole (26) and, at the other side, to a regulating device (10) of a hydraulic pump (6).
    5. Valve device according to any one of the preceding patent claims, the deflection of the control piston (14) being carried out by means of a control pressure or by means of electromagnets.
    6. Valve device according to any one of the preceding patent claims, the controlled consumer being a tool of a harvester head.
    EP01112733A 2000-08-21 2001-05-25 Valve system Expired - Lifetime EP1184576B1 (en)

    Applications Claiming Priority (2)

    Application Number Priority Date Filing Date Title
    DE10041168A DE10041168A1 (en) 2000-08-21 2000-08-21 valve means
    DE10041168 2000-08-21

    Publications (2)

    Publication Number Publication Date
    EP1184576A1 EP1184576A1 (en) 2002-03-06
    EP1184576B1 true EP1184576B1 (en) 2005-02-02

    Family

    ID=7653379

    Family Applications (1)

    Application Number Title Priority Date Filing Date
    EP01112733A Expired - Lifetime EP1184576B1 (en) 2000-08-21 2001-05-25 Valve system

    Country Status (2)

    Country Link
    EP (1) EP1184576B1 (en)
    DE (2) DE10041168A1 (en)

    Cited By (1)

    * Cited by examiner, † Cited by third party
    Publication number Priority date Publication date Assignee Title
    DE102009021103A1 (en) 2009-05-13 2010-11-18 Hydac Filtertechnik Gmbh Hydraulic valve device

    Families Citing this family (2)

    * Cited by examiner, † Cited by third party
    Publication number Priority date Publication date Assignee Title
    US6755214B2 (en) * 2001-08-03 2004-06-29 Ross Operating Value Company Solenoid valve for reduced energy consumption
    FI20115108L (en) 2011-02-03 2012-08-04 Parker Hannifin Mfg Finland Oy Directional valve with pressure control

    Family Cites Families (10)

    * Cited by examiner, † Cited by third party
    Publication number Priority date Publication date Assignee Title
    FR2297718A1 (en) * 1975-01-20 1976-08-13 Promecan Sisson Lehmann ELEMEN CONTROL EQUIPMENT
    DE3144362A1 (en) * 1981-11-07 1983-05-19 Robert Bosch Gmbh, 7000 Stuttgart Actuator which can be operated electromagnetically
    US5284220A (en) * 1988-07-25 1994-02-08 Atsugi Unisia Corporation Pressure control valve assembly for hydraulic circuit and automotive rear wheel steering system utilizing the same
    DE4102203A1 (en) * 1991-01-25 1992-07-30 Linde Ag HYDRAULIC DRIVE SYSTEM
    DE4212550C2 (en) * 1992-04-15 1998-12-10 Hydraulik Ring Gmbh Valve arrangement with a directional valve
    DE4224469A1 (en) * 1992-07-24 1994-01-27 Bosch Gmbh Robert Hydraulic directional control valve in piston spool design
    DE4234036A1 (en) * 1992-10-09 1994-04-14 Rexroth Mannesmann Gmbh Valve arrangement, esp. for driving hydraulic load on mobile machine - has non=return valve between control valve and press. sensing line or press. chamber
    DE19631803B4 (en) * 1996-08-07 2007-08-02 Bosch Rexroth Aktiengesellschaft Hydraulic control device
    DE19749639A1 (en) * 1997-11-10 1999-05-12 Mannesmann Rexroth Ag Hydraulic circuit
    US6269827B1 (en) * 1999-10-07 2001-08-07 Eaton Corporation Electrically operated pressure control valve

    Cited By (1)

    * Cited by examiner, † Cited by third party
    Publication number Priority date Publication date Assignee Title
    DE102009021103A1 (en) 2009-05-13 2010-11-18 Hydac Filtertechnik Gmbh Hydraulic valve device

    Also Published As

    Publication number Publication date
    DE50105234D1 (en) 2005-03-17
    EP1184576A1 (en) 2002-03-06
    DE10041168A1 (en) 2002-03-07

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