EP0310134B1 - Hydraulic control system for vehicles used in agriculture and civil engineering - Google Patents

Hydraulic control system for vehicles used in agriculture and civil engineering Download PDF

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Publication number
EP0310134B1
EP0310134B1 EP88116284A EP88116284A EP0310134B1 EP 0310134 B1 EP0310134 B1 EP 0310134B1 EP 88116284 A EP88116284 A EP 88116284A EP 88116284 A EP88116284 A EP 88116284A EP 0310134 B1 EP0310134 B1 EP 0310134B1
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EP
European Patent Office
Prior art keywords
control
pressure
valve
switch
delay
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
EP88116284A
Other languages
German (de)
French (fr)
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EP0310134A3 (en
EP0310134A2 (en
Inventor
Heribert Dipl.-Landw. Adams
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.)
Kloeckner Humboldt Deutz AG
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Kloeckner Humboldt Deutz AG
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Publication date
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Priority to AT88116284T priority Critical patent/ATE79664T1/en
Publication of EP0310134A2 publication Critical patent/EP0310134A2/en
Publication of EP0310134A3 publication Critical patent/EP0310134A3/en
Application granted granted Critical
Publication of EP0310134B1 publication Critical patent/EP0310134B1/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
    • 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
    • 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
    • F15B2211/3056—Assemblies of multiple valves
    • F15B2211/30585—Assemblies of multiple valves having a single valve for multiple 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
    • F15B2211/30—Directional control
    • F15B2211/31—Directional control characterised by the positions of the valve element
    • F15B2211/3105—Neutral or centre positions
    • F15B2211/3116—Neutral or centre positions the pump port being open in the centre position, e.g. so-called open 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
    • F15B2211/3138—Directional control characterised by the positions of the valve element the positions being discrete
    • 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
    • F15B2211/321—Directional control characterised by the type of actuation mechanically
    • F15B2211/322—Directional control characterised by the type of actuation mechanically actuated by biasing means, e.g. spring-actuated
    • 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
    • F15B2211/321—Directional control characterised by the type of actuation mechanically
    • F15B2211/324—Directional control characterised by the type of actuation mechanically manually, e.g. by using a lever or pedal
    • 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
    • F15B2211/355—Pilot pressure 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
    • F15B2211/63—Electronic controllers
    • F15B2211/6303—Electronic controllers using input signals
    • F15B2211/6306—Electronic controllers using input signals representing a pressure
    • F15B2211/6309—Electronic controllers using input signals representing a pressure the pressure being a pressure source supply 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
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/635—Circuits providing pilot pressure to pilot pressure-controlled fluid circuit elements
    • F15B2211/6355—Circuits providing pilot pressure to pilot pressure-controlled fluid circuit elements having valve means
    • 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
    • F15B2211/67—Methods for controlling pilot 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
    • F15B2211/71—Multiple output members, e.g. multiple hydraulic motors or cylinders

Definitions

  • the invention relates to a hydraulic control device for the working hydraulics of a vehicle which can be used in particular in agriculture and construction, preferably for a constant current system, with at least one control slide which can be fixed by a spring-loaded catch which can be hydraulically disengaged from the pressure in a control line and which, after being released, is automatically activated by a restoring force can be reset to its neutral position, the unlocking of the control spool can be triggered each time a predeterminable operating pressure is reached when the consumer, which is acted upon by the control spool, is switched on and is delayed by means of a delay device in the control line, which in turn is used to apply control pressure via a preload valve to the pump pressure line in Flow direction is connected before the spool.
  • each of the catches engaging on the control valves is designed as part of a piston guided in a cylinder, which is operated by spring force in the blocking direction and by pressure fluid in the Unlocking sense is applied.
  • the hydraulic spaces of the catches are connected to one another by a control line, which is connected directly to the pump pressure line via a hydraulic delay device for supplying hydraulic fluid.
  • the delay device consists exclusively of hydraulic components, which, however, at least partially require special manufacture due to their mode of operation. A device made of such components is quite expensive.
  • the invention has for its object to provide a delay device for a hydraulic control device of the type outlined at the outset, which can be produced inexpensively without custom-made components using commercially available simple means.
  • control line for the detent behind the bias valve to a pressure cell for actuating an electrical switch and parallel to it via a throttle and a check valve parallel to the detent an electromagnetically or spring-actuated two-way valve is connected, which is in the open position connects the control line with the line leading from the control slide to a further downstream control unit and that the switch of the pressure cell forms an electrical circuit with the electromagnetic actuator of the two-way valve in connection with a current source, which can be switched with a delay by a delay relay.
  • the electromagnetic two-way valve is loaded in the closing direction by a spring and that the switch of the pressure cell is in its open position in the closed position and comes into the open position when the pressure in the pressure cell rises.
  • the electromagnetic two-way valve is loaded by a spring in the opening direction and that the switch of the pressure cell is in its open state in the open position and comes into the closed position when the pressure in the pressure cell rises.
  • the circuit formed from the electromagnetic actuator of the two-way valve, the switch of the pressure cell and the relay can be connected to the positive pole of a power source via a switch arranged in the ignition lock of the vehicle.
  • a control slide 1 designed as a multi-way valve is provided, which is used to actuate, for example, an actuating cylinder, not shown.
  • This hydraulic consumer is connected to lines 2, 3.
  • Springs 4 and 5 acting on both sides of the control slide 1 ensure the centering of the movable slide part in the neutral position shown.
  • the control slide 1 has a detent 6 which is effective in a plurality of switching positions and can be mechanically engaged by spring force and hydraulically disengaged.
  • the catch 6 has a plunger 8 which is loaded by the force of a spring 7 and which, depending on the switching position of the control slide 1, engages in one of a plurality of recesses 9 in a slide part 10.
  • the detent 6 For the hydraulic actuation of the detent 6, it has a hydraulic actuator 11 which acts against the force of the spring 7 and which is coupled to a two-way valve 12.
  • a control line 14 provided for supplying the detent 6 with pressure fluid is connected to the actuator 11 by a line 15 and to the two-way valve 12 by a line 16 branching off the line 15.
  • the line 16 In the open position of the two-way valve 12 shown, caused by the spring 7, the line 16 is connected to the collecting container 19 for pressure fluid by a throttle 17 arranged in the spool of the two-way valve 12 by a line 18 connected to the outlet side thereof.
  • the control slide 1 has on the output side through a line 27 a connection to the line 18, which in turn is connected via a line 28 to the collecting container 19.
  • a biasing valve 29 is used to supply the control line 14 with pressure fluid, which is connected on the inlet side to the pressure line 22 and on the outlet side by a line 30 to a pressure cell 31.
  • the control line 14 is connected to the line 30 by switching on a throttle 32 and a check valve 33.
  • the hydraulic system has an electrical delay device 35 for the hydraulic actuation of the catch 6.
  • the delay device 35 has a two-way valve 37, which is acted upon by the force of a spring 36 in the closing direction and is actuated in the opening direction by an electromagnetic actuator 38.
  • the two-way valve 3 is connected on the input side to the control line 14 and on the output side through a line 39 to the line 23 leading from the control slide 1 to the control unit 24.
  • a switch 40 actuated by the latter, which is closed when the pressure cell 31 is unloaded and is connected on the one hand via ground to the negative pole of a power source and on the other hand via a line 41 to the electromagnetic actuator 38 of the two-way valve 37.
  • the actuator 38 is also by a Line 42 and a fuse 43 are connected to the positive pole of a power source via a switch 44 operating in the ignition lock of the vehicle.
  • a relay 45 is used as the delay element, which is connected to the negative pole of the current source with a connection 46 via ground. There are also connections of the delay relay 45 through a line 47 to line 42 and by a line 48 to line 41.
  • the switch 44 When starting the engine of the vehicle, the switch 44 is actuated in the closing direction, so that a circuit is closed by the line 42, the actuator 38, line 41 and the switch 40 in the closed position. As a result, the two-way valve 37 comes into the open position, so that the lines 14 and 39 come into connection with one another.
  • the hydraulic pump 20, which is constantly driven by the internal combustion engine, conveys hydraulic fluid through the pressure line 22 to the hydraulic system, so that when the control spool 1 is in neutral position, a circulating pressure is built up by the control unit 24 arranged at the end of the line 23, which pressure is then present in all lines connected directly to it.
  • control slide 1 If the control slide 1 is now shifted from the neutral position shown into an adjacent working position, then the consumer connected to the lines 2, 3 is pressurized with hydraulic fluid, while at the same time the inflow of hydraulic fluid to the line 23 or to the control unit 24 is interrupted. The line 23 is therefore depressurized. If the control slide 1 reaches the desired working position during its displacement, then the plunger 8 of the catch 6 engages in the corresponding recess 9 on the slide part 10 by the force of the spring 7. When supplying the control valve connected to spool 1 Consumer, for example an actuating cylinder, the pressure in line 22 increases when the piston is in the final position in the actuating cylinder, so that finally, at a predetermined pressure, the preload valve 29 connected to line 22 opens and releases pressure fluid into control line 30.
  • the control valve connected to spool 1 Consumer for example an actuating cylinder
  • a pressure is built up in the control line 30 so that hydraulic fluid passes through the throttle 32 and the check valve 33 into the control line 14.
  • No significant pressure can initially build up in the control line 14, since pressure fluid can continuously flow from the control line 14 through the open two-way valve 37 to line 23 and through lines 15, 16 and the throttle 17 in the two-way valve 16 to the return.
  • the switch 40 Due to the pressure increase in the control line 30, the switch 40 is opened via the pressure cell 31, so that the circuit closed via this is interrupted.
  • the delay relay 45 keeps the circuit closed for a time via the electromagnetic actuator 38, so that the two-way valve 37 initially remains in the open position.
  • the pressure reduction leads to the closing of the switch 40 via the pressure cell 31, so that the two-way valve 37 opens and releases the direct routes from the control line 14 to the lines 39 and 23 which are pressurized with circulating pressure.
  • the hydraulic system is thus in the starting position again and a new switching operation can take place on the control slide 1.
  • FIG. 2 shows a delay device 50, the structure of which essentially corresponds to that of the delay device 35 in FIG. 1.
  • the delay device 50 uses a delay relay 51 which closes a circuit with a delay when its excitation current is switched on.
  • a two-way valve 52 is provided, which is actuated by the force of a spring 53 in the opening direction and by an electromagnetic actuator 54 in the closing direction.
  • On the pressure cell 55 of this device there is a switch 56 which is in the initial position, i.e. with the pressurized can 55 in the open position.
  • the operation of this delay device 50 is such that the switch 56 closes at a certain pressure in the pressure cell 55, so that the delay relay 51 moves the two-way valve 52 with a delay against the force of the spring 53 in the closing direction against the force of the spring 53.

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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)
  • Lifting Devices For Agricultural Implements (AREA)
  • Vehicle Body Suspensions (AREA)

Abstract

Hydraulic control system for a tractor, with a control unit (24) for the power lift with at least one directional control valve (1) connected in the supply line (22, 23) to the control unit (24) and having neutral circulation for the pressure fluid, the directional control valve (1) serving to switch a consuming device on or off and being provided with a detent (6) which can be engaged automatically by spring force and disengaged by pressure fluid and, after an operation at the consuming device is complete, can in each case be unlocked in a delayed manner by an electro-hydraulic switching device (35 or 50). <IMAGE>

Description

Die Erfindung bezieht sich auf eine hydraulische Steuereinrichtung für die Arbeitshydraulik eines insbesondere land- und bauwirtschaftlich nutzbaren Fahrzeugs, vorzugsweise für ein Konstantstromsystem, mit zumindest einem durch eine federbelastete und vom Druck in einer Steuerleitung hydraulisch ausrückbare Raste festlegbaren Steuerschieber, der nach Entrastung mittels einer Rückstellkraft selbsttätig in seine Neutralstellung zurückstellbar ist, wobei die Entrastung des Steuerschiebers jeweils bei Erreichen eines vorgebbaren Betriebsdruckes bei eingeschaltetem, durch den Steuerschieber beaufschlagten Verbraucher auslösbar ist und verspätet mittels einer Verzögerungseinrichtung in der Steuerleitung einsetzt, die ihrerseits zur Beaufschlagung mit Steuerdruck über ein Vorspannventil mit der Pumpendruckleitung in Strömungsrichtung vor dem Steuerschieber verbunden ist.The invention relates to a hydraulic control device for the working hydraulics of a vehicle which can be used in particular in agriculture and construction, preferably for a constant current system, with at least one control slide which can be fixed by a spring-loaded catch which can be hydraulically disengaged from the pressure in a control line and which, after being released, is automatically activated by a restoring force can be reset to its neutral position, the unlocking of the control spool can be triggered each time a predeterminable operating pressure is reached when the consumer, which is acted upon by the control spool, is switched on and is delayed by means of a delay device in the control line, which in turn is used to apply control pressure via a preload valve to the pump pressure line in Flow direction is connected before the spool.

Es ist aus der DE-A-3 334 253 eine gattungsgleiche hydraulische Steuereinrichtung für die Arbeitshydraulik eines Schleppers bekanntgeworden, bei der jede der an den Steuerventilen angreifenden Rasten als Teil eines in einem Zylinder geführten Kolbens ausgebildet ist, der durch Federkraft im Sperrsinn und durch Druckflüssigkeit im Entriegelungssinn beaufschlagt wird. Die hydraulischen Räume der Rasten sind durch eine Steuerleitung miteinander verbunden, die zur Versorgung mit Druckflüssigkeit über eine hydraulische Verzögerungseinrichtung unmittelbar mit der Pumpendruckleitung in Verbindung steht. Bei dieser bekannten Steuereinrichtung besteht die Verzögerungseinrichtung ausschließlich aus hydraulischen Bauelementen, die jedoch aufgrund ihrer Wirkungsweise zumindest teilweise einer besonderen Anfertigung bedürfen. Eine Einrichtung aus derartigen Bauteilen ist recht kostenaufwendig.From DE-A-3 334 253 a generic hydraulic control device for the working hydraulics of a tractor has become known, in which each of the catches engaging on the control valves is designed as part of a piston guided in a cylinder, which is operated by spring force in the blocking direction and by pressure fluid in the Unlocking sense is applied. The hydraulic spaces of the catches are connected to one another by a control line, which is connected directly to the pump pressure line via a hydraulic delay device for supplying hydraulic fluid. In this known control device, the delay device consists exclusively of hydraulic components, which, however, at least partially require special manufacture due to their mode of operation. A device made of such components is quite expensive.

Der Erfindung liegt die Aufgabe zugrunde, eine Verzögerungseinrichtung für eine hydraulische Steuereinrichtung der eingangs umrissenen Gattung zu schaffen, die sich ohne Sonderanfertigungen von Bauteilen mit handelsüblichen einfachen Mitteln kostengünstig herstellen läßt.The invention has for its object to provide a delay device for a hydraulic control device of the type outlined at the outset, which can be produced inexpensively without custom-made components using commercially available simple means.

Die Aufgabe wird erfindungsgemäß dadurch gelöst, daß die Steuerleitung für die Raste hinter dem Vorspannventil an eine Druckdose zur Betätigung eines elektrischen Schalters und parallel dazu über eine Drossel sowie ein Rückschlagventil parallel zur Raste ein elektromagnetisch bzw. mit Federkraft betätigbares Zweiwegeventil angeschlossen ist, das in Offenstellung die Steuerleitung mit der vom Steuerschieber zu einem weiteren nachgeschalteten Steuergerät führenden Leitung verbindet und daß der Schalter der Druckdose mit dem elektromagnetischen Stellorgan des Zweiwegeventils in Verbindung mit einer Stromquelle einen elektrischen Schaltkreis bildet, der von einem Verzögerungsrelais verzögert schaltbar ist.The object is achieved in that the control line for the detent behind the bias valve to a pressure cell for actuating an electrical switch and parallel to it via a throttle and a check valve parallel to the detent an electromagnetically or spring-actuated two-way valve is connected, which is in the open position connects the control line with the line leading from the control slide to a further downstream control unit and that the switch of the pressure cell forms an electrical circuit with the electromagnetic actuator of the two-way valve in connection with a current source, which can be switched with a delay by a delay relay.

Alle hierfür benötigten elektrischen Bauteile können in der erforderlichen Ausführung fertig bezogen werden, so daß die Verzögerungseinrichtung kostengünstig herstellbar ist. Außerdem sind die Schaltverbindungen bei elektrischen Bauteilen leichter herzustellen, als bei hydraulischen Bauteilen, zumal in vielen Fällen vorgefertigte Leiterplatten zur Anwendung kommen.All the electrical components required for this can be obtained in the required version, so that the delay device is inexpensive to manufacture. In addition, the switching connections for electrical components are easier to manufacture than for hydraulic components, especially since prefabricated printed circuit boards are used in many cases.

Bei einem Relais, dessen Erregerstrom bei Abschaltung verzögert unterbrochen wird, ist vorgesehen, daß das elektromagnetische Zweiwegeventil im Schließsinn durch eine Feder belastet ist und daß der Schalter der Druckdose sich in deren unbeaufschlagtem Zustand in Schließstellung befindet sowie bei Druckanstieg in der Druckdose in Offenstellung gelangt.In the case of a relay whose excitation current is interrupted with a delay when switched off, it is provided that the electromagnetic two-way valve is loaded in the closing direction by a spring and that the switch of the pressure cell is in its open position in the closed position and comes into the open position when the pressure in the pressure cell rises.

Bei einem Relais, das bei Abschaltung des Erregerstromes verzögert schließt, ist vorgesehen, daß das elektromagnetische Zweiwegeventil im Öffnungssinn durch eine Feder belastet ist und daß der Schalter der Druckdose sich in deren unbeaufschlagtem Zustand in Offenstellung befindet sowie bei Druckanstieg in der Druckdose in Schließstellung gelangt.In the case of a relay which closes with a delay when the excitation current is switched off, it is provided that the electromagnetic two-way valve is loaded by a spring in the opening direction and that the switch of the pressure cell is in its open state in the open position and comes into the closed position when the pressure in the pressure cell rises.

Schließlich ist es zweckdienlich, wenn der aus dem elektromagnetischen Stellorgan des Zweiwegeventils, dem Schalter der Druckdose und dem Relais gebildete Stromkreis über ein im Zündschloß des Fahrzeugs angeordneten Schalter mit dem Pluspol einer Stromquelle verbindbar ist.Finally, it is useful if the circuit formed from the electromagnetic actuator of the two-way valve, the switch of the pressure cell and the relay can be connected to the positive pole of a power source via a switch arranged in the ignition lock of the vehicle.

Zwei Ausführungsbeispiele der Erfindung sind im folgenden anhand der Zeichnung näher beschrieben:
Es zeigt:

Fig. 1
eine schematische Darstellung einer hydraulischen Steuereinrichtung gemäß der Erfindung;
Fig. 2
ein anderes Ausführungsbeispiel.
Two exemplary embodiments of the invention are described in more detail below with reference to the drawing:
It shows:
Fig. 1
is a schematic representation of a hydraulic control device according to the invention;
Fig. 2
another embodiment.

In der als Blockschaltbild gezeigten hydraulischen Steuereinrichtung ist ein als Mehrwegeventil ausgebildeter Steuerschieber 1 vorgesehen, das zur Betätigung beispielsweise eines nicht dargestellten Stellzylinders dient. Dieser hydraulische Verbraucher ist an Leitungen 2, 3 angeschlossen. Beiderseits des Steuerschiebers 1 angreifende Federn 4 bzw. 5 sorgen für die Zentrierung des beweglichen Schieberteils in der gezeigten Neutralstellung. Ferner hat der Steuerschieber 1 eine in mehreren Schaltstellungen wirksame Raste 6, die mechanisch durch Federkraft einrückbar und hydraulisch ausrückbar ist. Die Raste 6 hat einen durch die Kraft einer Feder 7 belasteten Stößel 8, der je nach Schaltstellung des Steuerschiebers 1 in eine von mehreren Ausnehmungen 9 eines schieberteils 10 eingreift. Zur hydraulischen Betätigung der Raste 6 hat diese ein entgegen der Kraft der Feder 7 wirkendes hydraulisches Stellorgan 11, das mit einem Zweiwegeventil 12 gekoppelt ist. Eine zur Versorgung der Raste 6 mit Druckflüssigkeit vorgesehene Steuerleitung 14 ist durch eine Leitung 15 mit dem Stellorgan 11 und durch eine von der Leitung 15 abzweigende Leitung 16 mit dem Zweiwegeventil 12 verbunden. Bei der gezeigten, durch die Feder 7 bewirkten Offenstellung des Zweiwegeventils 12 ist die Leitung 16 durch eine im Schieder des Zweiwegeventils 12 angeordnete Drossel 17 durch eine ausgangsseitig an diese anschließende Leitung 18 mit dem Sammelbehälter 19 für Druckflüssigkeit verbunden.In the hydraulic control device shown as a block diagram, a control slide 1 designed as a multi-way valve is provided, which is used to actuate, for example, an actuating cylinder, not shown. This hydraulic consumer is connected to lines 2, 3. Springs 4 and 5 acting on both sides of the control slide 1 ensure the centering of the movable slide part in the neutral position shown. Furthermore, the control slide 1 has a detent 6 which is effective in a plurality of switching positions and can be mechanically engaged by spring force and hydraulically disengaged. The catch 6 has a plunger 8 which is loaded by the force of a spring 7 and which, depending on the switching position of the control slide 1, engages in one of a plurality of recesses 9 in a slide part 10. For the hydraulic actuation of the detent 6, it has a hydraulic actuator 11 which acts against the force of the spring 7 and which is coupled to a two-way valve 12. A control line 14 provided for supplying the detent 6 with pressure fluid is connected to the actuator 11 by a line 15 and to the two-way valve 12 by a line 16 branching off the line 15. In the open position of the two-way valve 12 shown, caused by the spring 7, the line 16 is connected to the collecting container 19 for pressure fluid by a throttle 17 arranged in the spool of the two-way valve 12 by a line 18 connected to the outlet side thereof.

Zur Versorgung der Steuereinrichtung mit Druckflüssigkeit dient eine Hydropumpe 20, die saugseitig an den Sammelbehälter 19 und ausgangsseitig mittels einer Druckleitung 22 an den Steuerschieber 1 angeschlossen ist. Vom Steuerschieber 1 führt ausgangsseitig eine Leitung 23 zu einem Regelsteuergerät 24, das zur Betätigung eines hinter einem Rückschlagventil 25 an eine Leitung 26 angeschlossenen, nicht dargestellten Krafthebers dient.A hydraulic pump 20, which is connected on the suction side to the collecting container 19 and on the outlet side by means of a pressure line 22 to the control slide 1, serves to supply the control device with pressure fluid. From the spool 1 leads on the output side a line 23 to a control control unit 24 which serves to actuate a power lift, not shown, connected to a line 26 behind a check valve 25.

Der Steuerschieber 1 hat ausgangsseitig durch eine Leitung 27 eine Verbindung mit der leitung 18, die ihrerseits durch eine Leitung 28 an den Sammelbehälter 19 angeschlossen ist. Zur Versorgung der Steuerleitung 14 mit Druckflüssigkeit dient ein Vorspannventil 29, das eingangsseitig an die Druckleitung 22 und ausgangsseitig durch eine Leitung 30 mit einer Druckdose 31 in Verbindung steht. An die Leitung 30 ist die Steuerleitung 14 unter Einschaltung einer Drossel 32 sowie eines Rückschlagventils 33 angeschlossen.The control slide 1 has on the output side through a line 27 a connection to the line 18, which in turn is connected via a line 28 to the collecting container 19. A biasing valve 29 is used to supply the control line 14 with pressure fluid, which is connected on the inlet side to the pressure line 22 and on the outlet side by a line 30 to a pressure cell 31. The control line 14 is connected to the line 30 by switching on a throttle 32 and a check valve 33.

Das hydraulische System hat eine elektrische Verzögerungseinrichtung 35 für die hydraulische Betätigung der Raste 6. Die Verzögerungseinrichtung 35 weist ein durch die Kraft einer Feder 36 im Schließsinn beaufschlagtes Zweiwegeventil 37 auf, das durch ein elektromagnetisches Stellorgan 38 im Öffnungssinn betätigt wird. Das Zweiwegeventil 3 ist eingangsseitig an die Steuerleitung 14 und ausgangsseitig durch eine Leitung 39 an die vom Steuerschieber 1 zum Regelsteuergerät 24 führende Leitung 23 angeschlossen.The hydraulic system has an electrical delay device 35 for the hydraulic actuation of the catch 6. The delay device 35 has a two-way valve 37, which is acted upon by the force of a spring 36 in the closing direction and is actuated in the opening direction by an electromagnetic actuator 38. The two-way valve 3 is connected on the input side to the control line 14 and on the output side through a line 39 to the line 23 leading from the control slide 1 to the control unit 24.

An der Druckdose 31 sitzt ein von dieser betätigter Schalter 40, der bei entlasteter Druckdose 31 geschlossen ist und einerseits über Masse mit dem Minuspol einer Stromquelle sowie andererseits durch eine Leitung 41 mit dem elektromagnetischen Stellorgan 38 des Zweiwegeventils 37 verbunden ist. Das Stellorgan 38 ist außerdem durch eine Leitung 42 und eine Sicherung 43 über ein im Zündschloß des Fahrzeugs betätigenden schalter 44 an den Pluspol einer Stromquelle angeschlossen. Als Verzögerungselement dient ein Relais 45, das mit einem Anschluß 46 über Masse am Minuspol der Stromquelle liegt. Ferner bestehen Verbindungen des Verzögerungsrelais 45 durch eine Leitung 47 mit der Leitung 42 sowie durch eine Leitung 48 mit der Leitung 41.On the pressure cell 31 is a switch 40 actuated by the latter, which is closed when the pressure cell 31 is unloaded and is connected on the one hand via ground to the negative pole of a power source and on the other hand via a line 41 to the electromagnetic actuator 38 of the two-way valve 37. The actuator 38 is also by a Line 42 and a fuse 43 are connected to the positive pole of a power source via a switch 44 operating in the ignition lock of the vehicle. A relay 45 is used as the delay element, which is connected to the negative pole of the current source with a connection 46 via ground. There are also connections of the delay relay 45 through a line 47 to line 42 and by a line 48 to line 41.

Beim Anlassen der Brennkraftmaschine des Fahrzeugs wird der Schalter 44 im Schließsinn betätigt, so daß durch die Leitung 42, das Stellorgan 38, Leitung 41 sowie den in Schließstellung befindlichen Schalter 40 ein Stromkreis geschlossen wird. Demzufolge gelangt das Zweiwegeventil 37 in Offenstellung, so daß die Leitungen 14 und 39 miteinander in Verbindung kommen. Die von der Brennkraftmaschine ständig angetriebene Hydropumpe 20 fördert Druckflüssigkeit durch die Druckleitung 22 zum hydraulischen System, wodurch bei Neutralstellung des Steuerschiebers 1 durch das am Ende der Leitung 23 angeordnete Regelsteuergerät 24 ein Umlaufdruck aufgebaut wird, der dann in allen damit direkt verbundenen Leitungen ansteht. Wird nun der Steuerschieber 1 aus der gezeigten Neutralstellung in eine benachbarte Arbeitsstellung verschoben, dann erfolgt eine Beaufschlagung des an die Leitungen 2, 3 angeschlossenen Verbrauchers mit Druckflüssigkeit, während gleichzeitig der Zufluß von Druckflüssigkeit zur Leitung 23 bzw. zum Regelsteuergerät 24 unterbrochen wird. Die Leitung 23 wird folglich drucklos. Erreicht der Steuerschieber 1 bei seiner Verschiebung die gewünschte Arbeitsstellung, dann rastet der Stößel 8 der Raste 6 durch die Kraft der Feder 7 in die entsprechende Aussparung 9 am Schieberteil 10 ein. Bei der Versorgung des am Steuerschieber 1 angeschlossenen Verbrauchers, beispielsweise eines Stellzylinders, steigt der Druck in der Leitung 22 bei Endlage des Kolbens im Stellzylinder, so daß schließlich bei einem vorbestimmten Druck das an die Leitung 22 angeschlossene Vorspannventil 29 öffnet und Druckflüssigkeit in die Steuerleitung 30 entläßt. Hierdurch wird in der Steuerleitung 30 ein Druck aufgebaut, so daß Druckflüssigkeit durch die Drossel 32 und das Rückschlagventil 33 in die Steuerleitung 14 gelangt. In der Steuerleitung 14 kann sich zunächst kein nennenswerter Druck aufbauen, da ständig Druckflüssigkeit von der Steuerleitung 14 durch das offene Zweiwegeventil 37 zur Leitung 23 und durch die Leitungen 15, 16 und die Drossel 17 im Zweiwegeventil 16 zum Rücklauf abströmen kann. Durch den druckanstieg in der Steuerleitung 30 wird über die Druckdose 31 der Schalter 40 geöffnet, so daß der über diesen geschlossene Stromkreis unterbrochen wird. Das Verzögerungsrelais 45 hält jedoch den Stromkreis über das elektromagnetische Stellorgan 38 noch für eine Zeit geschlossen, so daß das Zweiwegeventil 37 zunächst noch in Offenstellung bleibt. Erst nach Unterbrechung des Stromkreises durch das Verzögerungsrelais 45 wird das Zweiwegeventil 37 durch die Kraft der Feder 36 geschlossen und es kann sich in der Steuerleitung 14 der volle Steuerdruck aufbauen, der Schließlich zum Auslösen der Raste 9 führt. Der Steuerschieber 1 wird folglich durch die Kraft der entsprechenden Feder 4 bzw. 5 wieder in seine Neutralstellung zurückgestellt. Folglich verbindet der Steuerschieber 1 wieder die Druckleitung 22 mit der Leitung 23, die das Regelsteuergerät 24 mit Druckmittel versorgt. In den Leitungen 22, 23 und in dem damit verbundenen Leitungssytem stellt sich folglich wieder ein Umlaufdruck ein, für den das Vorspannventil 29 gesperrt ist. In der Steuerleitung 30 und ebenso in der Steuerleitung 14 fällt der Druck ab, da diese Durch die Drossel 17 im Zweiwegeventil 12 mit dem Rücklauf in Verbindung steht. Die Druckminderung führt über die Druckdose 31 zum Schließen des Schalters 40, so daß das Zweiwegeventil 37 öffnet und den direkten Wege von der Steuerleitung 14 zu den mit Umlaufdruck beaufschlagten Leitungen 39 und 23 freigibt. Damit befindet sich das hydraulische System wieder in Ausgangslage und es kann ein neuer Schaltvorgang am Steuerschieber 1 erfolgen.When starting the engine of the vehicle, the switch 44 is actuated in the closing direction, so that a circuit is closed by the line 42, the actuator 38, line 41 and the switch 40 in the closed position. As a result, the two-way valve 37 comes into the open position, so that the lines 14 and 39 come into connection with one another. The hydraulic pump 20, which is constantly driven by the internal combustion engine, conveys hydraulic fluid through the pressure line 22 to the hydraulic system, so that when the control spool 1 is in neutral position, a circulating pressure is built up by the control unit 24 arranged at the end of the line 23, which pressure is then present in all lines connected directly to it. If the control slide 1 is now shifted from the neutral position shown into an adjacent working position, then the consumer connected to the lines 2, 3 is pressurized with hydraulic fluid, while at the same time the inflow of hydraulic fluid to the line 23 or to the control unit 24 is interrupted. The line 23 is therefore depressurized. If the control slide 1 reaches the desired working position during its displacement, then the plunger 8 of the catch 6 engages in the corresponding recess 9 on the slide part 10 by the force of the spring 7. When supplying the control valve connected to spool 1 Consumer, for example an actuating cylinder, the pressure in line 22 increases when the piston is in the final position in the actuating cylinder, so that finally, at a predetermined pressure, the preload valve 29 connected to line 22 opens and releases pressure fluid into control line 30. As a result, a pressure is built up in the control line 30 so that hydraulic fluid passes through the throttle 32 and the check valve 33 into the control line 14. No significant pressure can initially build up in the control line 14, since pressure fluid can continuously flow from the control line 14 through the open two-way valve 37 to line 23 and through lines 15, 16 and the throttle 17 in the two-way valve 16 to the return. Due to the pressure increase in the control line 30, the switch 40 is opened via the pressure cell 31, so that the circuit closed via this is interrupted. However, the delay relay 45 keeps the circuit closed for a time via the electromagnetic actuator 38, so that the two-way valve 37 initially remains in the open position. Only after the circuit has been interrupted by the delay relay 45 is the two-way valve 37 closed by the force of the spring 36 and the full control pressure can build up in the control line 14, which finally leads to the release of the detent 9. The control slide 1 is consequently reset to its neutral position by the force of the corresponding spring 4 or 5. Consequently, the control slide 1 connects the pressure line 22 to the line 23, which supplies the control unit 24 with pressure medium. In the lines 22, 23 and in the line system connected therewith, a circulation pressure is consequently set again, for which the preload valve 29 is blocked. In the control line 30 and also in the control line 14 the pressure drops since it is connected to the return through the throttle 17 in the two-way valve 12. The pressure reduction leads to the closing of the switch 40 via the pressure cell 31, so that the two-way valve 37 opens and releases the direct routes from the control line 14 to the lines 39 and 23 which are pressurized with circulating pressure. The hydraulic system is thus in the starting position again and a new switching operation can take place on the control slide 1.

In Figur 2 ist eine Verzögerungseinrichtung 50 gezeigt, deren Aufbau im wesentlichen mit demjenigen der Verzögerungseinrichtung 35 in Fig. 1 übereinstimmt. Im Unterschied hierzu findet bei der Verzögerungseinrichtung 50 ein Verzögerungsrelais 51 Verwendung, das einen Stromkreis bei Einschaltung seines Erregerstromes verzögert schließt. Demgemäß ist hierbei ein Zweiwegeventil 52 vorgesehen, das durch die Kraft einer Feder 53 im Öffnungssinn und durch ein elektromagnetisches Stellorgan 54 im Schließsinn betätigt wird. An der Druckdose 55 dieser Einrichtung sitzt ein Schalter 56, der sich in Ausgangsstellung, d.h. bei unbeaufschlagter Druckdose 55 in Offenstellung befindet. Die Wirkungsweise ist bei dieser Verzögerungseinrichtung 50 so, daß bei einem bestimmten Druck in der Druckdose 55 der schalter 56 schließt, so daß das Verzögerungsrelais 51 das Zweiwegeventil 52 über das elektromagnetische Stellorgan 54 entgegen der Kraft der Feder 53 verzögert im Schließsinn bewegt.FIG. 2 shows a delay device 50, the structure of which essentially corresponds to that of the delay device 35 in FIG. 1. In contrast to this, the delay device 50 uses a delay relay 51 which closes a circuit with a delay when its excitation current is switched on. Accordingly, a two-way valve 52 is provided, which is actuated by the force of a spring 53 in the opening direction and by an electromagnetic actuator 54 in the closing direction. On the pressure cell 55 of this device there is a switch 56 which is in the initial position, i.e. with the pressurized can 55 in the open position. The operation of this delay device 50 is such that the switch 56 closes at a certain pressure in the pressure cell 55, so that the delay relay 51 moves the two-way valve 52 with a delay against the force of the spring 53 in the closing direction against the force of the spring 53.

Claims (4)

  1. A hydraulic control apparatus for the hydraulic working system of a vehicle usable especially in agriculture and building economy, preferably for a constant - flow system, with at least one control slide valve (1) fixable by a spring-loaded catch (6) which is hydraulically disengageable by the pressure in a control conduit (14, 30), which slide valve after release is returnable automatically by means of a return force (springs 4, 5) into its neutral position, while the release of the control slide valve (1) occurs in each case on reaching a pre-determined operational pressure with a consumer (conduits 2, 3) in action, being loaded by the control slide valve (1), and with delay by means of a retarding device (35 or 50) in the control conduit (14, 30), which in turn is connected, for charging with control pressure, by way of a pressurising valve (29) with the pump delivery conduit (22), before the control slide valve (1), in the direction of flow, characterised in that the control conduit (14, 30) for the catch (6) is attached, behind the pressurising valve (29), to a pressure element (31) for the actuation of an electric switch (46 or 56) and parallel thereto by way of a throttle (32) and a non-return valve (33) parallel to the catch (6) to a two-way valve (37 or 52) actuatable electromagnetically or with spring force, which in the open position connects the control conduit (14, 30) with the conduit (23) leading from the control slide valve (1) to a further, subsequently connected, control appliance, and in that the switch (46 or 56) of the pressure element (31 or 55) with the electro-magnetic setting element (38 or 54) of the two-way valve (37 or 52), in combination with a current source,forms an electric switch circuit which is switchable with delay by a delay relay (45 or 56).
  2. A control apparatus according to Claim 1, wherein the relay (45) is formed so that on switching off of its energising current it interrupts a current circuit with delay, characterised in that the electro-magnetic two-way valve (37) is loaded in the closing direction by a spring (36) and in that the switch (40) of the pressure element (31) is situated in the closed position when the pressure element (31) is in the unloaded condition and passes into the open position on a rise of pressure in the pressure element (31).
  3. A control apparatus according to Claim 1, wherein the relay (51) is so formed that it closes a current circuit with delay on switching off of the energising current, characterised in that the electro-magnetic two-way valve (52) is loaded in the opening direction by a spring (53) and in that the switch (56) of the pressure element (55) is situated in the open position when the pressure element (55) is in the unloaded condition and passes into the closed position on a rise in pressure in the pressure element (55).
  4. A control apparatus according to any one of the preceding Claims, characterised in that the current circuit formed from the electro-magnetic setting element (38 or 54) of the two-way valve (37 or 52), the switch (46 or 56) of the pressure element (31 or 55) and the relay (45 or 51) is connectable through a switch (44) arranged in the ignition lock of the vehicle with the positive pole of a current source.
EP88116284A 1987-10-02 1988-10-01 Hydraulic control system for vehicles used in agriculture and civil engineering Expired - Lifetime EP0310134B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT88116284T ATE79664T1 (en) 1987-10-02 1988-10-01 HYDRAULIC CONTROL DEVICE FOR THE WORKING HYDRAULICS OF AN AGRICULTURAL AND CONSTRUCTION VEHICLE.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3733371 1987-10-02
DE19873733371 DE3733371A1 (en) 1987-10-02 1987-10-02 HYDRAULIC CONTROL DEVICE FOR THE WORKING HYDRAULICS OF A AGRICULTURAL AND CONSTRUCTIVE VEHICLE

Publications (3)

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EP0310134A2 EP0310134A2 (en) 1989-04-05
EP0310134A3 EP0310134A3 (en) 1990-04-25
EP0310134B1 true EP0310134B1 (en) 1992-08-19

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EP88116284A Expired - Lifetime EP0310134B1 (en) 1987-10-02 1988-10-01 Hydraulic control system for vehicles used in agriculture and civil engineering

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EP (1) EP0310134B1 (en)
AT (1) ATE79664T1 (en)
DE (2) DE3733371A1 (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2440949A (en) * 2006-08-15 2008-02-20 Agco Gmbh Spool valve
DE102008042386A1 (en) * 2008-09-26 2010-04-08 Zf Friedrichshafen Ag Locking device for a valve spool
CN101660551B (en) * 2009-09-25 2011-08-24 中国北方车辆研究所 Oil gas suspension hydraulic locking device
CN103352889B (en) * 2013-07-08 2015-07-01 太原理工大学 Method for buffering hydraulic system shock of crawler loader

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3646968A (en) * 1970-09-30 1972-03-07 Sperry Rand Corp Power transmission valve with detent
US3716075A (en) * 1971-10-12 1973-02-13 Parker Hannifin Corp Power assist mechanism for fluid control valves
US4195551A (en) * 1977-06-23 1980-04-01 Gresen Manufacturing Company Hydraulic control valve including electromagnetic detent
DE3125482A1 (en) * 1981-06-29 1983-01-13 Günter Till Präzisionsmechanik, 3330 Helmstedt Control valve
DE3203465A1 (en) * 1982-02-03 1983-08-11 Klöckner-Humboldt-Deutz AG, 5000 Köln PRINTING MEDIUM CIRCUIT, IN PARTICULAR FOR A MOWING MACHINE
DE8311270U1 (en) * 1982-04-16 1983-11-17 Steyr-Daimler-Puch AG, 1011 Wien Device for actuating the hydraulic piston drive of an additional device, in particular for agricultural tractors
DE3334253A1 (en) * 1983-09-22 1985-04-04 Klöckner-Humboldt-Deutz AG, 5000 Köln HYDRAULIC CONTROL DEVICE FOR WORKING HYDRAULICS OF TRACTORS

Also Published As

Publication number Publication date
DE3733371A1 (en) 1989-04-13
DE3873868D1 (en) 1992-09-24
ATE79664T1 (en) 1992-09-15
EP0310134A3 (en) 1990-04-25
EP0310134A2 (en) 1989-04-05

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