EP1884853A1 - Hydraulic control valve and electrohydraulic clamping device - Google Patents

Hydraulic control valve and electrohydraulic clamping device Download PDF

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Publication number
EP1884853A1
EP1884853A1 EP06016027A EP06016027A EP1884853A1 EP 1884853 A1 EP1884853 A1 EP 1884853A1 EP 06016027 A EP06016027 A EP 06016027A EP 06016027 A EP06016027 A EP 06016027A EP 1884853 A1 EP1884853 A1 EP 1884853A1
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EP
European Patent Office
Prior art keywords
spring
control
control valve
stop
bias
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP06016027A
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German (de)
French (fr)
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EP1884853B1 (en
Inventor
Georg Neumair
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.)
Hawe Hydraulik SE
Original Assignee
Hawe Hydraulik GmbH and Co KG
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Publication date
Application filed by Hawe Hydraulik GmbH and Co KG filed Critical Hawe Hydraulik GmbH and Co KG
Priority to AT06016027T priority Critical patent/ATE422255T1/en
Priority to EP06016027A priority patent/EP1884853B1/en
Priority to DE502006002776T priority patent/DE502006002776D1/en
Publication of EP1884853A1 publication Critical patent/EP1884853A1/en
Application granted granted Critical
Publication of EP1884853B1 publication Critical patent/EP1884853B1/en
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B25HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25BTOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
    • B25B5/00Clamps
    • B25B5/06Arrangements for positively actuating jaws
    • B25B5/061Arrangements for positively actuating jaws with fluid drive
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/02Systems essentially incorporating special features for controlling the speed or actuating force of an output member
    • F15B11/028Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the actuating force
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/30Directional control
    • F15B2211/305Directional control characterised by the type of valves
    • F15B2211/30525Directional control valves, e.g. 4/3-directional control valve
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/30Directional control
    • F15B2211/31Directional control characterised by the positions of the valve element
    • F15B2211/3105Neutral or centre positions
    • F15B2211/3116Neutral or centre positions the pump port being open in the centre position, e.g. so-called open centre
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/30Directional control
    • F15B2211/32Directional control characterised by the type of actuation
    • F15B2211/327Directional control characterised by the type of actuation electrically or electronically
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/40Flow control
    • F15B2211/405Flow control characterised by the type of flow control means or valve
    • F15B2211/40515Flow control characterised by the type of flow control means or valve with variable throttles or orifices
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/50Pressure control
    • F15B2211/505Pressure control characterised by the type of pressure control means
    • F15B2211/50554Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure downstream of the pressure control means, e.g. pressure reducing valve
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/50Pressure control
    • F15B2211/515Pressure control characterised by the connections of the pressure control means in the circuit
    • F15B2211/5151Pressure control characterised by the connections of the pressure control means in the circuit being connected to a pressure source and a directional control valve
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/50Pressure control
    • F15B2211/52Pressure control characterised by the type of actuation
    • F15B2211/528Pressure control characterised by the type of actuation actuated by fluid pressure
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/50Pressure control
    • F15B2211/57Control of a differential pressure
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/70Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/705Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
    • F15B2211/7051Linear output members
    • F15B2211/7053Double-acting output members
    • F15B2211/7054Having equal piston areas

Definitions

  • the invention relates to a hydraulic control valve according to the preamble of patent claim 1, and to an electro-hydraulic tensioning device according to the preamble of patent claim 16.
  • control spring bias can be changed mechanically.
  • it is necessary to adjust the support of the control spring for example via screw.
  • the exact value of the newly set bias voltage is then unknown.
  • a pressure gauge must be used to check which regulated pressure results from the changeover.
  • Such an application is, for example, an electro-hydraulic clamping device of a machine tool (as shown in FIG. 4), in which it has been customary to provide two parallel-connected control valves whose control springs are set to specific biases, and by means of a 3/2-way solenoid valve to switch between the two control valves to selectively set one of two predetermined clamping pressure values in the tensioning device.
  • the effort of two control valves each with a spring section is high and costly.
  • the invention has for its object to provide a hydraulic control valve, which is structurally simple, inexpensive and reliable and can optionally set two predetermined, different control spring biases without mechanical manipulation. Part of the task is also to achieve the same function as in the known solution according to FIG. 4 in a structurally simpler manner with an electro-hydraulic tensioning device.
  • the spring abutment can be selectively adjusted hydraulically between two mechanically fixed control spring bias positions associated with a higher and a lower control spring bias, only a single hydraulic control valve controls either a higher or a lower, exactly, depending on the hydraulic actuation of the spring section predetermined outlet pressure. Even if there should be a power failure that renders the hydraulic loading of the spring section ineffective, the bias of the control spring is not completely or indefinitely degraded, but always maintains one of the predetermined control spring biases due to the mechanical constraint.
  • one of two predetermined control spring biases is selectively remotely controlled with a single control valve, namely, a higher or lower control spring bias resulting in a higher or lower clamping pressure in the chuck, the value of each of which is precisely predetermined ,
  • a higher or lower control spring bias resulting in a higher or lower clamping pressure in the chuck, the value of each of which is precisely predetermined
  • the spring bearing is hydraulically adjusted in the hydraulic control valve by means of a control piston, which is reciprocable between two attacks.
  • Each stop defines a biasing position of the control spring that corresponds to a particular value of the regulated output pressure of the control valve. Since the stops are mechanically positioned, the spring abutment can not move into any unknown or unwanted position.
  • At least one of the stops is mechanically adjustable in order to set a value for the control spring bias and thus the value of the regulated output pressure in advance can.
  • both attacks are mechanically and independently adjustable, so that both control spring bias values are variable as needed, without affecting each other.
  • the spring section is designed so that the spring abutment automatically assumes either the control spring biasing position for the higher control spring bias or for the lower control spring bias voltage in the event of a power failure.
  • Which control spring biasing position is ultimately selected in the event of a power failure depends on the requirements of the system in which the hydraulic control valve is used. In an electro-hydraulic clamping device for a machine tool, it is usually important to ensure the higher control spring bias and thus holding the higher clamping pressure in case of power failure for safety reasons.
  • a preferred embodiment of the hydraulic control valve is characterized in that the spring abutment is arranged on a fixed in the adjusting piston pull rod that is arranged for the actuating piston, the first stop a spring sleeve containing a stiffer, preferably biased retaining spring than the control spring, and that the second stop is arranged on the end of the pull rod facing away from the control spring in the spring sleeve.
  • the main purpose of the retaining spring is to ensure that the spring abutment assumes the higher control spring biasing position in case of a power failure, which eliminates the hydraulic loading of the actuating piston.
  • the adjusting piston is fixed on the drawbar by a clamping element.
  • the clamping element it may be possible to vary the bias of the retaining spring in a particular area.
  • the spring sleeve with the spring abutment in an outer housing relative to a predetermined position in the outer housing position for the highest possible control spring bias voltage can be screwed.
  • the first stop is set in the desired position.
  • the second stop is arranged on a screw-threaded in the spring sleeve, so that the position of the second stop can be selected regardless of the position of the first stop.
  • the adjusting piston with its control chamber is located within the threaded areas between the outer housing and the spring sleeve or the spring sleeve and the threaded insert, the threaded areas are suitably sealed.
  • the control chamber for the actuating piston is expediently provided at the first stop, which is connected via a thread passing through the channel with a pressure port of the outer housing.
  • the actuating piston can be applied by the second stop hydraulically against the first stop to adjust the position of the spring abutment for the higher control spring bias.
  • a 3/2-way magnetic seat valve is expediently arranged, which can be fed with supply pressure, preferably via a housed in the outer housing supply channel, which may be connected to a pressure port of the control valve.
  • the supply channel could be acted upon from another source of pressure.
  • the spring abutment in which the spring abutment is in the lower control spring biasing position at a power failure and elimination of the hydraulic loading of the actuating piston, characterized in that the spring abutment is directly connected to the actuating piston, which in a control chamber a cylinder is arranged, which defines the second stop for the lower control spring bias and is screwed into a stop sleeve defining the first stop for the higher control spring bias, the stop sleeve is screwed into an outer housing, so that ultimately the positions of both Stops are selectable as needed.
  • a hydraulic control valve R of the type shown in FIGS. 2 and 3 may generally be any control valve that operates with a control spring, such as a pressure reducing valve or a pressure relief valve, and is suitably applicable in hydraulic systems, of which an electro-hydraulic tensioning device is shown in FIG 1 is selected.
  • a control spring such as a pressure reducing valve or a pressure relief valve
  • An electro-hydraulic tensioner S in Fig. 1 can be used on a machine tool to clamp workpieces, for example, workpieces that require two different clamping pressures for clamping during machining.
  • a in the embodiment shown double-acting hydraulic clamping cylinder 1 is connected via working lines 2, 3 to a directional control valve 4 (2/2-solenoid control valve), of which one line leads to a tank line 6 on the one hand.
  • a connection of the directional control valve 4 is connected via a line 7 to the hydraulic control valve R, which in turn is in communication with the pump line 5 and the tank line 6.
  • a 3/2-way solenoid valve (seat valve) is arranged, and connected to the pump line 5 and the tank line 6.
  • the 3/2-way magnetic switching valve 8 has a black / white magnet 9 and a return spring 15 and is connected via a line to a control chamber of a control piston 13.
  • With the adjusting piston 13 is a spring abutment 12 in connection, on which a control spring 11 is supported, which acts on a valve member 10 of the control valve R with a certain bias.
  • a retaining spring 14 acts.
  • At least the bias of the control spring 11 is adjustable. Further, the bias of the control spring 11 can be changed by means of the 3/2-way magnetic switching valve 8 between two predetermined bias values, which are associated with a higher and a lower clamping pressure for the clamping cylinder 1.
  • the actuating piston 13 is adjusted to the right, so that the lower control spring bias is set (lower clamping pressure).
  • the lower bias of the control spring 11 is so high that in no case completely collapses the clamping pressure or falls too much in an uncontrolled manner.
  • FIG. 4 The same function as in FIG. 1 is achieved in a known solution (FIG. 4 prior art) in that between the pump line 5, the tank line 6 and the directional control valve 4 two hydraulic control valves R1, R2 (eg pressure reducing valves) are arranged parallel, of which the control valve R1 has a biasing spring 11 ', which acts on the valve member 10a with the higher biasing force (higher clamping pressure), while the other control valve R2 has a less biased control spring 11 ", which acts on the valve member 10b (lower clamping pressure).
  • the 3/2-way solenoid valve 8 ' connects (de-energized) in the switching position shown, the output of the first control valve R1 with the line 7 (higher clamping pressure), in the energized state, however, the output of the other control valve R2 to the line 7 (lower clamping pressure).
  • Fig. 2 shows in axial section a hydraulic control valve R, which is formed for example as a pressure reducing valve and can be used inter alia for the electro-hydraulic tensioning device in Fig. 1.
  • the valve member 10 is acted upon by the control spring 11, which is supported on the spring abutment 12.
  • the spring abutment 12 is connected via a pull rod 23 with the actuating piston 13, which is fixed on the pull rod 23 by a clamping element 22.
  • the actuating piston 13 is slidably housed in a control chamber 30 of a spring sleeve 18 which includes a retaining spring 14.
  • the retaining spring 14 is, optionally, biased, and stiffer than the control spring 11.
  • the retaining spring is supported between a stop in the spring sleeve 18 and the back of the spring plate 12 so that it determines the position of the spring abutment 12 relative to the spring sleeve 18.
  • the spring sleeve 18 is screwed with a thread in an internal thread 17 of an outer housing 14 and defines a first stop 28 for the actuating piston 13.
  • the first stop 28 determines the position of the spring abutment 12 in relation to the outer housing 16 as long as the actuating piston 13 is not acted upon.
  • a further stop 29 is formed, which defines the position of the spring abutment 12 for the highest possible bias of the control spring 11.
  • a screw 20 is screwed, which defines a second stop 21 for the left-side end of the pull rod 23 and the actuator piston 13.
  • the position of the spring abutment 12 relative to the outer housing 16 determines the lower preload of the control spring 11.
  • the threaded portions 17, 19 are sealed because the control chamber 30 is sealed via a supply channel 27 with a supply connection 26 of the outer housing 16 is connected to the control chamber 30 to pressurize or relieve.
  • the 3/2-way solenoid valve 8 is externally attached to the outer housing 16 and is connected to a tank port 25 in the outer housing 16, via which the interior of the spring sleeve 18 is relieved of pressure. Furthermore, the solenoid valve 8 is connected to a supply connection, not shown, which runs, for example, in the interior of the outer housing 16 and leads to the pressure connection of the control valve or valve member 10.
  • This spring section F of the control valve R not only makes it possible to switch hydraulically from the setting of the higher preload pressure of the control spring to the setting for the lower preload pressure (when the actuating piston 13 is acted upon), but also allows the positions of the stops 21, 28 individually and independently adjustable, either by screwing the screw 20 relative to the spring sleeve 18 and / or by screwing the spring sleeve 18 relative to the outer housing 16 to set two specific output pressures of the control valve in advance.
  • the pressure supply for acting on the actuating piston 13 could also come from a different pressure source than from the pressure connection of the control valve.
  • the higher control spring bias (higher clamping pressure in the tensioning device) is automatically adjusted because when the control piston 13 abuts the stop 28, the position of the spring abutment 12 is adjusted and held by the retaining spring 14 in the spring sleeve 18.
  • the spring section F in Fig. 3 is used for a control valve, which assumes the position with the lower bias of the control spring 11 in case of power failure.
  • the spring abutment 12 is connected directly to the actuating piston 13, which is contained in the control chamber 30 of a cylinder 20 'axially displaceable.
  • the cylinder 20 ' fines with its front side the second stop 21 corresponding to the position of the spring abutment 12 for the lower bias of the control spring 11.
  • the cylinder 20' is in a stop sleeve 18 'screwed to adjust the axial position of the second stopper 21.
  • the stop sleeve 18 ' defines the first abutment 28 for the spring abutment 12 (higher control spring biasing position), which is set when the actuating piston 13 is acted upon.
  • the stop sleeve 18 ' is screwed into the outer housing 16 in order to adjust the position of the first stop 28 can.

Abstract

The valve (R) has a control spring (11) loading a valve unit (10) and supported at a spring thrust bearing (12). The thrust bearing is hydraulically adjustable between two mechanically determined control spring-clamping positions by using a setting piston (13), where the positions are assigned to higher and lower control spring-clamping. The piston is fixed to a connecting rod by using a clamping unit, and is arranged in a control chamber that is provided in a spring housing (18), where the control chamber is connected with a pressure connection of an outer housing.

Description

Die Erfindung betrifft ein Hydraulik-Regelventil gemäß dem Oberbegriff des Patentanspruchs 1, sowie eine elektrohydraulische Spannvorrichtung gemäß dem Oberbegriff des Patentanspruchs 16.The invention relates to a hydraulic control valve according to the preamble of patent claim 1, and to an electro-hydraulic tensioning device according to the preamble of patent claim 16.

Bei eine Regelfeder enthaltenden Hydraulik-Regelventilen bekannter Bauart lässt sich die Regelfeder-Vorspannung mechanisch ändern. Dazu ist es erforderlich, die Abstützung der Regelfeder beispielsweise über Schraubverbindungen zu verstellen. Der exakte Wert der neu eingestellten Vorspannung ist dann nicht bekannt. Es muss beispielsweise über ein Manometer überprüft werden, welcher geregelter Druck sich aus der Umstellung ergibt. Es besteht bei solchen Hydraulik-Regelventilen, insbesondere bei Druckminder- oder Druckbegrenzungsventilen, ein Bedarf, bei manchen Einsatzfällen eine rasche Umstellung der Regelfeder-Vorspannung zwischen zwei genau bekannten Vorspannwerten vornehmen zu können.In a control spring containing hydraulic control valves of known type, the control spring bias can be changed mechanically. For this purpose, it is necessary to adjust the support of the control spring, for example via screw. The exact value of the newly set bias voltage is then unknown. For example, a pressure gauge must be used to check which regulated pressure results from the changeover. There is a need in such hydraulic control valves, especially in pressure reducing or pressure relief valves, to be able to make a rapid changeover of the control spring bias between two well-known bias values in some applications.

Ein solcher Einsatzfall ist beispielsweise eine elektrohydraulische Spannvorrichtung einer Werkzeugmaschine (wie anhand Fig. 4 gezeigt), bei der es bisher üblich ist, zwei parallel geschaltete Regelventile vorzusehen, deren Regelfedern auf bestimmte Vorspannungen eingestellt sind, und mittels eines 3/2-Wege-Magnetventils zwischen den beiden Regelventilen umzuschalten, um in der Spannvorrichtung wahlweise einen von zwei vorbestimmten Spanndruckwerten einzustellen. Der Aufwand zweier Regelventile jeweils mit einer Federsektion ist hoch und kostenintensiv.Such an application is, for example, an electro-hydraulic clamping device of a machine tool (as shown in FIG. 4), in which it has been customary to provide two parallel-connected control valves whose control springs are set to specific biases, and by means of a 3/2-way solenoid valve to switch between the two control valves to selectively set one of two predetermined clamping pressure values in the tensioning device. The effort of two control valves each with a spring section is high and costly.

Es ist zwar bei elektrohydraulischen Spannvorrichtungen von Werkzeugmaschinen bekannt, den durch ein Regelventil eingestellten Spanndruck elektrisch zu ändern. Hierfür wird ein die Regelfeder abstützender Stellkolben mit einem bestimmten Steuerdruck beaufschlagt, der die jeweilige Regelfeder-Vorspannung erzeugt, und für den Stellkolben eine relativ aufwendige Ventilkombination mit wenigstens einem elektrisch ansteuerbaren Proportional-Druckregelventil vorzusehen. Diese Lösung ist schaltungstechnisch aufwendig und kostenintensiv. Ferner besteht die Gefahr, dass bei einem Stromausfall der Spanndruck vollständig zusammenbricht, was in vielen Fällen nicht zulässig ist, oder dieser Nachteil nur dadurch umgangen werden kann, dass ein zusätzliches Sicherungsventil eingegliedert wird, das bei einem Stromausfall den für den Stellkolben eingestellten Steuerdruck hält.Although it is known in electro-hydraulic clamping devices of machine tools to change the set by a control valve clamping pressure electrically. For this purpose, a control spring supporting the adjusting piston is acted upon by a certain control pressure, which generates the respective control spring bias, and provide for the control piston a relatively complex valve combination with at least one electrically controllable proportional pressure control valve. This solution is circuitry expensive and expensive. Furthermore, there is a risk that in the event of a power failure, the clamping pressure is complete collapses, which is in many cases not allowed, or this disadvantage can only be avoided by the fact that an additional safety valve is incorporated, which holds the control pressure set for the actuator piston in the event of a power failure.

Der Erfindung liegt die Aufgabe zugrunde, ein Hydraulik-Regelventil anzugeben, das baulich einfach, kostengünstig und betriebssicher ist und wahlweise zwei vorab festgelegte, unterschiedliche Regelfeder-Vorspannungen ohne mechanische Manipulationen einstellen lässt. Teil der Aufgabe ist es auch, bei einer elektrohydraulischen Spannvorrichtung die gleiche Funktion wie bei der bekannten Lösung gemäß Fig. 4 auf baulich einfachere Weise zu erzielen.The invention has for its object to provide a hydraulic control valve, which is structurally simple, inexpensive and reliable and can optionally set two predetermined, different control spring biases without mechanical manipulation. Part of the task is also to achieve the same function as in the known solution according to FIG. 4 in a structurally simpler manner with an electro-hydraulic tensioning device.

Die gestellte Aufgabe wird mit den Merkmalen des Patentanspruchs 1 und des Patentanspruchs 16 gelöst.The stated object is achieved with the features of claim 1 and of claim 16.

Dass sich das Federwiderlager wahlweise hydraulisch zwischen zwei mechanisch festgelegten Regelfeder-Vorspannpositionen verstellen lässt, die einer höheren und einer niedrigeren Regelfeder-Vorspannung zugeordnet sind, regelt nur ein einziges Hydraulik-Regelventil abhängig von der hydraulischen Betätigung der Federsektion entweder einen höheren oder einen niedrigeren, exakt vorherbestimmten Ausgangsdruck. Selbst wenn es zu einem Stromausfall kommen sollte, der die Hydraulikbeaufschlagung der Federsektion wirkungslos macht, wird die Vorspannung der Regelfeder nicht vollständig oder auf unbestimmte Weise abgebaut, sondern bleibt aufgrund der mechanischen Festlegung stets eine der vorbestimmten Regelfeder-Vorspannungen aufrechtgehalten.The fact that the spring abutment can be selectively adjusted hydraulically between two mechanically fixed control spring bias positions associated with a higher and a lower control spring bias, only a single hydraulic control valve controls either a higher or a lower, exactly, depending on the hydraulic actuation of the spring section predetermined outlet pressure. Even if there should be a power failure that renders the hydraulic loading of the spring section ineffective, the bias of the control spring is not completely or indefinitely degraded, but always maintains one of the predetermined control spring biases due to the mechanical constraint.

In der elektrohydraulischen Spannvorrichtung wird mit einem einzigen Regelventil wahlweise eine von zwei vorbestimmten Regelfeder-Vorspannungen ferngesteuert eingestellt, und zwar eine höhere oder eine niedrigere Regelfeder-Vorspannung, aus denen ein höherer oder ein niedrigerer Spanndruck in der Spannvorrichtung resultiert, dessen Wert jeweils genau vorbestimmt ist. Bei einem Stromausfall, der das Magnetventil betrifft, wird zuverlässig einer der beiden Spanndrücke gehalten. Auf diese Weise wird baulich einfach und kostengünstig ein Sicherheitsaspekt für die Spannvorrichtung erzielt, wie er von vielen Anwendern gefordert ist.In the electro-hydraulic tensioner, one of two predetermined control spring biases is selectively remotely controlled with a single control valve, namely, a higher or lower control spring bias resulting in a higher or lower clamping pressure in the chuck, the value of each of which is precisely predetermined , In the event of a power failure affecting the solenoid valve, one of the two clamping pressures is reliably maintained. In this way, structurally simple and cost-effective a safety aspect for the clamping device is achieved, as required by many users.

Zweckmäßig wird im Hydraulik-Regelventil das Federlager mittels eines Stellkolbens hydraulisch verstellt, der zwischen zwei Anschlägen hin- und herbewegbar ist. Jeder Anschlag definiert eine Vorspannposition der Regelfeder, die einem bestimmten Wert des geregelten Ausgangsdrucks des Regelventils entspricht. Da die Anschläge mechanisch positioniert sind, kann sich das Federwiderlager in keine unbekannte oder nicht gewollte Position verstellen.Appropriately, the spring bearing is hydraulically adjusted in the hydraulic control valve by means of a control piston, which is reciprocable between two attacks. Each stop defines a biasing position of the control spring that corresponds to a particular value of the regulated output pressure of the control valve. Since the stops are mechanically positioned, the spring abutment can not move into any unknown or unwanted position.

Zweckmäßig ist zumindest einer der Anschläge mechanisch einstellbar, um einen Wert für die Regelfeder-Vorspannung und damit den Wert des geregelten Ausgangsdrucks vorab einstellen zu können. Zweckmäßig sind sogar beide Anschläge mechanisch und unabhängig voneinander einstellbar, so dass beide Regelfeder-Vorspannungswerte nach Bedarf variierbar sind, ohne einander zu beeinflussen.Suitably, at least one of the stops is mechanically adjustable in order to set a value for the control spring bias and thus the value of the regulated output pressure in advance can. Suitably, even both attacks are mechanically and independently adjustable, so that both control spring bias values are variable as needed, without affecting each other.

Um gegebenen Sicherheitsanforderungen gerecht zu werden, ist die Federsektion so ausgebildet, dass das Federwiderlager bei einem Stromausfall selbsttätig entweder die Regelfeder-Vorspannposition für die höhere Regelfeder-Vorspannung oder für die niedrigere Regelfeder-Vorspannung einnimmt. Welche Regelfeder-Vorspannposition letztendlich bei einem Stromausfall gewählt wird, hängt von den Anforderungen an das System ab, in welchem das Hydraulik-Regelventil verwendet wird. Bei einer elektrohydraulischen Spannvorrichtung für eine Werkzeugmaschine ist es im Regelfall wichtig, bei einem Stromausfall aus Sicherheitsgründen die höhere Regelfeder-Vorspannung und damit das Halten des höheren Spanndrucks sicherzustellen.To meet given safety requirements, the spring section is designed so that the spring abutment automatically assumes either the control spring biasing position for the higher control spring bias or for the lower control spring bias voltage in the event of a power failure. Which control spring biasing position is ultimately selected in the event of a power failure depends on the requirements of the system in which the hydraulic control valve is used. In an electro-hydraulic clamping device for a machine tool, it is usually important to ensure the higher control spring bias and thus holding the higher clamping pressure in case of power failure for safety reasons.

Eine bevorzugte Ausführungsform des Hydraulik-Regelventils zeichnet sich dadurch aus, dass das Federwiderlager an einer im Stellkolben festgelegten Zugstange angeordnet ist, dass für den Stellkolben der erste Anschlag einer Federhülse angeordnet ist, die eine steifere, vorzugsweise vorgespannte Haltefeder als die Regelfeder enthält, und dass der zweite Anschlag an der der Regelfeder abgewandten Endseite der Zugstange in der Federhülse angeordnet ist. Der Hauptzweck der Haltefeder besteht darin, bei einem Stromausfall, der die hydraulische Beaufschlagung des Stellkolbens entfallen lässt, sicherzustellen, dass das Federwiderlager die höhere Regelfeder-Vorspannposition einnimmt.A preferred embodiment of the hydraulic control valve is characterized in that the spring abutment is arranged on a fixed in the adjusting piston pull rod that is arranged for the actuating piston, the first stop a spring sleeve containing a stiffer, preferably biased retaining spring than the control spring, and that the second stop is arranged on the end of the pull rod facing away from the control spring in the spring sleeve. The main purpose of the retaining spring is to ensure that the spring abutment assumes the higher control spring biasing position in case of a power failure, which eliminates the hydraulic loading of the actuating piston.

Aus montagetechnischen Gründen wird hierbei der Stellkolben auf der Zugstange durch ein Spannelement festgelegt. Mittels des Spannelementes ist es gegebenenfalls möglich, auch die Vorspannung der Haltefeder in einem bestimmten Bereich zu variieren.For assembly reasons, in this case the adjusting piston is fixed on the drawbar by a clamping element. By means of the clamping element, it may be possible to vary the bias of the retaining spring in a particular area.

Zweckmäßig ist die Federhülse mit dem Federwiderlager in einem Außengehäuse relativ zu einer im Außengehäuse vorgegebenen Position für die höchstmögliche Regelfeder-Vorspannung verschraubbar. Durch Verschrauben der Federhülse wird der erste Anschlag in die jeweils gewünschte Position eingestellt.Advantageously, the spring sleeve with the spring abutment in an outer housing relative to a predetermined position in the outer housing position for the highest possible control spring bias voltage can be screwed. By screwing the spring sleeve, the first stop is set in the desired position.

Der zweite Anschlag ist an einem in der Federhülse vorschraubbaren Schraubeinsatz angeordnet, so dass sich auch die Position des zweiten Anschlages unabhängig von der Position des ersten Anschlags wählen lässt.The second stop is arranged on a screw-threaded in the spring sleeve, so that the position of the second stop can be selected regardless of the position of the first stop.

Da sich der Stellkolben mit seiner Steuerkammer innerhalb der Gewindebereiche zwischen dem Außengehäuse und der Federhülse bzw. der Federhülse und dem Schraubeinsatz befindet, sind die Gewindebereiche zweckmäßig abgedichtet.Since the adjusting piston with its control chamber is located within the threaded areas between the outer housing and the spring sleeve or the spring sleeve and the threaded insert, the threaded areas are suitably sealed.

In der Federhülse ist zweckmäßig beim ersten Anschlag die Steuerkammer für den Stellkolben vorgesehen, die über einen den Gewindebereich durchsetzenden Kanal mit einem Druckanschluss des Außengehäuses verbunden ist. Auf baulich einfache Weise lässt sich der Stellkolben vom zweiten Anschlag hydraulisch gegen den ersten Anschlag anlegen, um die Position des Federwiderlagers für die höhere Regelfeder-Vorspannung einzustellen.In the spring sleeve, the control chamber for the actuating piston is expediently provided at the first stop, which is connected via a thread passing through the channel with a pressure port of the outer housing. In a structurally simple manner, the actuating piston can be applied by the second stop hydraulically against the first stop to adjust the position of the spring abutment for the higher control spring bias.

Auf dem Außengehäuse wird zweckmäßig ein 3/2-Wege-Magnetsitzventil angeordnet, das mit Versorgungsdruck speisbar ist, vorzugsweise über einen im Außengehäuse untergebrachten Versorgungskanal, der an einen Druckanschluss des Regelventils angeschlossen sein kann. Alternativ könnte der Versorgungskanal auch aus einer anderen Druckquelle beaufschlagt werden.On the outer housing a 3/2-way magnetic seat valve is expediently arranged, which can be fed with supply pressure, preferably via a housed in the outer housing supply channel, which may be connected to a pressure port of the control valve. Alternatively, the supply channel could be acted upon from another source of pressure.

Bei einer alternativen Ausführungsform des Hydraulik-Regelventils, bei dem bei einem Stromausfall und Wegfall der Hydraulikbeaufschlagung des Stellkolbens das Federwiderlager in die niedrigere Regelfeder-Vorspannposition geht, zeichnet sich dadurch aus, dass das Federwiderlager direkt mit dem Stellkolben verbunden ist, der in einer Steuerkammer eines Zylinders angeordnet ist, welcher den zweiten Anschlag für die niedrigere Regelfeder-Vorspannung definiert und in einer Anschlaghülse verschraubbar ist, die den ersten Anschlag für die höhere Regelfeder-Vorspannung definiert, wobei die Anschlaghülse in einem Außengehäuse verschraubbar ist, so dass letztendlich die Positionen beider Anschläge nach Bedarf wählbar sind.In an alternative embodiment of the hydraulic control valve, in which the spring abutment is in the lower control spring biasing position at a power failure and elimination of the hydraulic loading of the actuating piston, characterized in that the spring abutment is directly connected to the actuating piston, which in a control chamber a cylinder is arranged, which defines the second stop for the lower control spring bias and is screwed into a stop sleeve defining the first stop for the higher control spring bias, the stop sleeve is screwed into an outer housing, so that ultimately the positions of both Stops are selectable as needed.

Anhand der Zeichnungen werden Ausführungsformen des Erfindungsgegenstandes sowie ein Beispiel aus dem Stand der Technik erläutert. Es zeigen:

Fig. 1
ein Blockschaltbild einer elektrohydraulischen Spannvorrichtung, beispielsweise einer Werkzeugmaschine, mit einem erfindungsgemäßen Regelventil,
Fig. 2
einen Achsschnitt des Regelventils,
Fig. 3
einen schematischen Achsschnitt einer anderen Ausführungsform des Regelventils, und
Fig. 4
ein Blockschaltbild einer bekannten elektrohydraulischen Spannvorrichtung (Stand der Technik).
With reference to the drawings, embodiments of the subject invention and an example of the prior art will be explained. Show it:
Fig. 1
1 is a block diagram of an electro-hydraulic tensioning device, for example a machine tool, with a control valve according to the invention;
Fig. 2
an axial section of the control valve,
Fig. 3
a schematic axial section of another embodiment of the control valve, and
Fig. 4
a block diagram of a known electro-hydraulic tensioning device (prior art).

Ein Hydraulik-Regelventil R der in den Fig. 2 und 3 gezeigten Bauart kann allgemein jedes Regelventil sein, das mit einer Regelfeder arbeitet, beispielsweise ein Druckminderventil oder ein Druckbegrenzungsventil, und ist zweckmäßig einsetzbar in Hydrauliksystemen, von denen als Beispiel eine elektrohydraulische Spannvorrichtung in Fig. 1 ausgewählt ist. Diese Beispiele sowohl für das Regelventil als auch das System, in dem das Regelventil verwendbar ist, sind jedoch hier nicht beschränkend aufgezählt.A hydraulic control valve R of the type shown in FIGS. 2 and 3 may generally be any control valve that operates with a control spring, such as a pressure reducing valve or a pressure relief valve, and is suitably applicable in hydraulic systems, of which an electro-hydraulic tensioning device is shown in FIG 1 is selected. However, these examples for both the control valve and the system in which the control valve is usable are not listed here in a restrictive manner.

Eine elektrohydraulische Spannvorrichtung S in Fig. 1 kann an einer Werkzeugmaschine verwendet werden, um Werkstücke zu spannen, und zwar beispielsweise Werkstücke, die zum Spannen bei der Bearbeitung zwei verschiedene Spanndrücke benötigen. Ein in der gezeigten Ausführungsform doppelt wirkender Hydraulik-Spannzylinder 1 ist über Arbeitsleitungen 2, 3 an ein Richtungs-Steuerventil 4 (2/2-Magnetsteuerventil) angeschlossen, von dem einerseits eine Leitung zu einer Tankleitung 6 führt.An electro-hydraulic tensioner S in Fig. 1 can be used on a machine tool to clamp workpieces, for example, workpieces that require two different clamping pressures for clamping during machining. A in the embodiment shown double-acting hydraulic clamping cylinder 1 is connected via working lines 2, 3 to a directional control valve 4 (2/2-solenoid control valve), of which one line leads to a tank line 6 on the one hand.

Ein Anschluss des Richtungs-Steuerventils 4 ist über eine Leitung 7 an das hydraulische Regelventil R angeschlossen, das seinerseits mit der Pumpenleitung 5 und der Tankleitung 6 in Verbindung ist. Parallel zum Regelventil R ist ein 3/2-Wege-Magnetschaltventil (Sitzventil) angeordnet, und an die Pumpenleitung 5 und die Tankleitung 6 angeschlossen. Das 3/2-Wege-Magnetschaltventil 8 weist einen Schwarz/Weiß-Magneten 9 und eine Rückstellfeder 15 auf und ist über eine Leitung an eine Steuerkammer eines Stellkolbens 13 angeschlossen. Mit dem Stellkolben 13 steht ein Federwiderlager 12 in Verbindung, an dem sich eine Regelfeder 11 abstützt, die mit einer bestimmten Vorspannung ein Ventilglied 10 des Regelventils R beaufschlagt. An der anderen Seite des Stellkolbens 13 wirkt eine Haltefeder 14. Zumindest die Vorspannung der Regelfeder 11 ist einstellbar. Ferner lässt sich die Vorspannung der Regelfeder 11 mittels des 3/2-Wege-Magnetschaltventils 8 zwischen zwei vorbestimmten Vorspannwerten verändern, die einem höheren und einem niedrigeren Spanndruck für den Spannzylinder 1 zugeordnet sind.A connection of the directional control valve 4 is connected via a line 7 to the hydraulic control valve R, which in turn is in communication with the pump line 5 and the tank line 6. Parallel to the control valve R, a 3/2-way solenoid valve (seat valve) is arranged, and connected to the pump line 5 and the tank line 6. The 3/2-way magnetic switching valve 8 has a black / white magnet 9 and a return spring 15 and is connected via a line to a control chamber of a control piston 13. With the adjusting piston 13 is a spring abutment 12 in connection, on which a control spring 11 is supported, which acts on a valve member 10 of the control valve R with a certain bias. At the other side of the actuating piston 13, a retaining spring 14 acts. At least the bias of the control spring 11 is adjustable. Further, the bias of the control spring 11 can be changed by means of the 3/2-way magnetic switching valve 8 between two predetermined bias values, which are associated with a higher and a lower clamping pressure for the clamping cylinder 1.

In der gezeigten Schaltstellung ist der Stellkolben 13 entlastet, so dass dank der Wirkung der Haltefeder 14 die Regelfeder 11 auf den Wert für die höhere Vorspannung und damit für den höheren Spanndruck eingestellt ist. Der Magnet 9 ist entregt.In the switching position shown, the actuating piston 13 is relieved, so that thanks to the action of the retaining spring 14, the control spring 11 is set to the value for the higher bias and thus for the higher clamping pressure. The magnet 9 is de-energized.

Wird für die andere Schaltstellung der Magnet 9 erregt, dann wird der Stellkolben 13 nach rechts verstellt, so dass die niedrigere Regelfeder-Vorspannung eingestellt wird (niedrigerer Spanndruck). Die niedrigere Vorspannung der Regelfeder 11 ist jedoch so hoch, dass in keinem Fall der Spanndruck vollständig zusammenbricht oder in nicht kontrollierter Weise zu stark abfällt.If the magnet 9 is energized for the other switching position, then the actuating piston 13 is adjusted to the right, so that the lower control spring bias is set (lower clamping pressure). However, the lower bias of the control spring 11 is so high that in no case completely collapses the clamping pressure or falls too much in an uncontrolled manner.

Die gleiche Funktion wie in Fig. 1 wird bei einer bekannten Lösung (Fig. 4 Stand der Technik) dadurch erzielt, dass zwischen der Pumpenleitung 5, der Tankleitung 6 und dem Richtungs-Steuerventil 4 zwei Hydraulik-Regelventile R1, R2 (z.B. Druckminderventile) parallel angeordnet sind, von denen das Regelventil R1 eine Vorspannfeder 11' aufweist, die das Ventilglied 10a mit der höheren Vorspannkraft beaufschlagt (höherer Spanndruck), während das andere Regelventil R2 eine weniger vorgespannte Regelfeder 11" aufweist, die das Ventilglied 10b beaufschlagt (niedrigerer Spanndruck). Das 3/2-Wege-Magnetschaltventil 8' verbindet in der gezeigten Schaltstellung (entregt) den Ausgang des ersten Regelventils R1 mit der Leitung 7 (höherer Spanndruck), in erregtem Zustand hingegen den Ausgang des anderen Regelventils R2 mit der Leitung 7 (niedrigerer Spanndruck).The same function as in FIG. 1 is achieved in a known solution (FIG. 4 prior art) in that between the pump line 5, the tank line 6 and the directional control valve 4 two hydraulic control valves R1, R2 (eg pressure reducing valves) are arranged parallel, of which the control valve R1 has a biasing spring 11 ', which acts on the valve member 10a with the higher biasing force (higher clamping pressure), while the other control valve R2 has a less biased control spring 11 ", which acts on the valve member 10b (lower clamping pressure The 3/2-way solenoid valve 8 'connects (de-energized) in the switching position shown, the output of the first control valve R1 with the line 7 (higher clamping pressure), in the energized state, however, the output of the other control valve R2 to the line 7 (lower clamping pressure).

Bei beiden Lösungen in den Fig. 1 und 4 führt ein Ausfall der Strombeaufschlagung des 3/2-Wege-Magnetschaltventils 8 bzw. 8' dazu, dass automatisch der höhere Spanndruck gehalten wird. Allerdings sind hierfür in Fig. 2 die beiden Regelventile mit jeweils einer eigenen Federsektion erforderlich, was einen relativ hohen Aufwand bedingt, während in Fig. 1 mit einem einzigen Regelventil R (z.B. einem Druckminderventil oder Druckbegrenzungsventil) ausgekommen wird.In both solutions in Figs. 1 and 4, a failure of the current application of the 3/2-way solenoid valve 8 and 8 'causes automatically the higher clamping pressure is maintained. However, the two control valves, each with its own spring section, are required for this purpose in FIG. 2, which requires a relatively high outlay, while in FIG. 1 a single control valve R (for example a pressure-reducing valve or pressure-limiting valve) is used.

Fig. 2 zeigt im Achsschnitt ein Hydraulik-Regelventil R, das beispielsweise als Druckminderventil ausgebildet ist und unter anderem für die elektrohydraulische Spannvorrichtung in Fig. 1 verwendet werden kann. Das Ventilglied 10 wird von der Regelfeder 11 beaufschlagt, die sich an dem Federwiderlager 12 abstützt. Das Federwiderlager 12 ist über eine Zugstange 23 mit dem Stellkolben 13 verbunden, der auf der Zugstange 23 durch ein Spannelement 22 festgelegt ist. Der Stellkolben 13 ist in einer Steuerkammer 30 einer Federhülse 18 verschiebbar untergebracht, die eine Haltefeder 14 enthält. Die Haltefeder 14 ist, gegebenenfalls, vorgespannt, und steifer als die Regelfeder 11. Die Haltefeder stützt sich zwischen einem Anschlag in der Federhülse 18 und der Rückseite des Federtellers 12 ab, so dass sie die Position des Federwiderlagers 12 relativ zur Federhülse 18 festlegt. Die Federhülse 18 ist mit einem Gewinde in einem Innengewinde 17 eines Außengehäuses 14 verschraubbar und definiert einen ersten Anschlag 28 für den Stellkolben 13. Der erste Anschlag 28 bestimmt die Position des Federwiderlagers 12 in Relation zum Außengehäuse 16, solange der Stellkolben 13 nicht beaufschlagt ist.Fig. 2 shows in axial section a hydraulic control valve R, which is formed for example as a pressure reducing valve and can be used inter alia for the electro-hydraulic tensioning device in Fig. 1. The valve member 10 is acted upon by the control spring 11, which is supported on the spring abutment 12. The spring abutment 12 is connected via a pull rod 23 with the actuating piston 13, which is fixed on the pull rod 23 by a clamping element 22. The actuating piston 13 is slidably housed in a control chamber 30 of a spring sleeve 18 which includes a retaining spring 14. The retaining spring 14 is, optionally, biased, and stiffer than the control spring 11. The retaining spring is supported between a stop in the spring sleeve 18 and the back of the spring plate 12 so that it determines the position of the spring abutment 12 relative to the spring sleeve 18. The spring sleeve 18 is screwed with a thread in an internal thread 17 of an outer housing 14 and defines a first stop 28 for the actuating piston 13. The first stop 28 determines the position of the spring abutment 12 in relation to the outer housing 16 as long as the actuating piston 13 is not acted upon.

Im Außengehäuse 16 ist ein weiterer Anschlag 29 geformt, der die Position des Federwiderlagers 12 für die höchstmögliche Vorspannung der Regelfeder 11 definiert. In einem Innengewinde 19 der Federhülse 18 ist ein Schraubeinsatz 20 verschraubbar, der einen zweiten Anschlag 21 für das linksseitige Ende der Zugstange 23 bzw. den Stellkolben 13 definiert. Bei Anlage der Zugstange 23 an dem zweiten Anschlag 21 (bei Beaufschlagung des Stellkolbens 13) bestimmt die Position des Federwiderlagers 12 relativ zum Außengehäuse 16 die niedrigere Vorspannung der Regelfeder 11. Die Gewindebereiche 17, 19 sind abgedichtet, weil die Steuerkammer 30 über einen Versorgungskanal 27 mit einem Versorgungsanschluss 26 des Außengehäuses 16 verbunden ist, um die Steuerkammer 30 mit Druck beaufschlagen oder entlasten zu können. Das 3/2-Wege-Magnetschaltventil 8 ist außen an das Außengehäuse 16 angebaut und ist mit einem Tankanschluss 25 im Außengehäuse 16 verbunden, über den auch der Innenraum der Federhülse 18 druckentlastet wird. Ferner steht das Magnetventil 8 mit einem nicht gezeigten Versorgungsanschluss in Verbindung, der beispielsweise im Inneren des Außengehäuses 16 verläuft und zum Druckanschluss des Regelventils bzw. Ventilglieds 10 führt.In the outer housing 16, a further stop 29 is formed, which defines the position of the spring abutment 12 for the highest possible bias of the control spring 11. In an internal thread 19 of the spring sleeve 18, a screw 20 is screwed, which defines a second stop 21 for the left-side end of the pull rod 23 and the actuator piston 13. When the pull rod 23 abuts against the second stop 21 (when the actuating piston 13 is acted upon), the position of the spring abutment 12 relative to the outer housing 16 determines the lower preload of the control spring 11. The threaded portions 17, 19 are sealed because the control chamber 30 is sealed via a supply channel 27 with a supply connection 26 of the outer housing 16 is connected to the control chamber 30 to pressurize or relieve. The 3/2-way solenoid valve 8 is externally attached to the outer housing 16 and is connected to a tank port 25 in the outer housing 16, via which the interior of the spring sleeve 18 is relieved of pressure. Furthermore, the solenoid valve 8 is connected to a supply connection, not shown, which runs, for example, in the interior of the outer housing 16 and leads to the pressure connection of the control valve or valve member 10.

Diese Federsektion F des Regelventils R ermöglicht es nicht nur, wahlweise hydraulisch von der Einstellung des höheren Vorspanndrucks der Regelfeder auf die Einstellung für den niedrigeren Vorspanndruck umzustellen (bei Beaufschlagen des Stellkolbens 13), sondern lässt es auch zu, die Positionen der Anschläge 21, 28 individuell und voneinander unabhängig zu verstellen, und zwar entweder durch Verschrauben des Schraubeinsatzes 20 relativ zur Federhülse 18 und/oder durch Verschrauben der Federhülse 18 relativ zum Außengehäuse 16, um vorab zwei bestimmte Ausgangsdrücke des Regelventils festzulegen.This spring section F of the control valve R not only makes it possible to switch hydraulically from the setting of the higher preload pressure of the control spring to the setting for the lower preload pressure (when the actuating piston 13 is acted upon), but also allows the positions of the stops 21, 28 individually and independently adjustable, either by screwing the screw 20 relative to the spring sleeve 18 and / or by screwing the spring sleeve 18 relative to the outer housing 16 to set two specific output pressures of the control valve in advance.

Die Druckversorgung zur Beaufschlagung des Stellkolbens 13 könnte auch von einer anderen Druckquelle als vom Druckanschluss des Regelventils kommen.The pressure supply for acting on the actuating piston 13 could also come from a different pressure source than from the pressure connection of the control valve.

Bei einem Stromausfall wird automatisch die höhere Regelfeder-Vorspannung (höherer Spanndruck in der Spannvorrichtung) eingestellt, weil bei Anlage des Stellkolbens 13 am Anschlag 28 die Position des Federwiderlagers 12 von der Haltefeder 14 in der Federhülse 18 eingestellt und gehalten wird.In the event of a power failure, the higher control spring bias (higher clamping pressure in the tensioning device) is automatically adjusted because when the control piston 13 abuts the stop 28, the position of the spring abutment 12 is adjusted and held by the retaining spring 14 in the spring sleeve 18.

Die Federsektion F in Fig. 3 dient für ein Regelventil, das bei einem Stromausfall die Stellung mit der niedrigeren Vorspannung der Regelfeder 11 einnimmt. Das Federwiderlager 12 ist direkt mit dem Stellkolben 13 verbunden, der in der Steuerkammer 30 eines Zylinders 20' axial verschiebbar enthalten ist. Der Zylinder 20' definiert mit seiner Stirnseite den zweiten Anschlag 21 entsprechend der Position des Federwiderlagers 12 für die niedrigere Vorspannung der Regelfeder 11. Der Zylinder 20' ist in einer Anschlaghülse 18' verschraubbar, um die axiale Position des zweiten Anschlags 21 einzustellen. Die Anschlaghülse 18' definiert den ersten Anschlag 28 für das Federwiderlager 12 (höhere Regelfeder-Vorspannposition), die bei Beaufschlagen des Stellkolbens 13 eingestellt wird. Die Anschlaghülse 18' ist in dem Außengehäuse 16 verschraubbar, um auch die Position des ersten Anschlags 28 einstellen zu können.The spring section F in Fig. 3 is used for a control valve, which assumes the position with the lower bias of the control spring 11 in case of power failure. The spring abutment 12 is connected directly to the actuating piston 13, which is contained in the control chamber 30 of a cylinder 20 'axially displaceable. The cylinder 20 'defines with its front side the second stop 21 corresponding to the position of the spring abutment 12 for the lower bias of the control spring 11. The cylinder 20' is in a stop sleeve 18 'screwed to adjust the axial position of the second stopper 21. The stop sleeve 18 'defines the first abutment 28 for the spring abutment 12 (higher control spring biasing position), which is set when the actuating piston 13 is acted upon. The stop sleeve 18 ' is screwed into the outer housing 16 in order to adjust the position of the first stop 28 can.

Claims (16)

Hydraulik-Regelventil (R), insbesondere Druckminderventil oder Druckbegrenzungsventil, mit einer Federsektion (F), die eine ein Ventilelement (10) beaufschlagende Regelfeder (11) enthält, die an einem Federwiderlager (12) abgestützt ist, dadurch gekennzeichnet, dass das Federwiderlager (12) zur Änderung der Vorspannung der Regelfeder (11) wahlweise hydraulisch zwischen zwei mechanisch festgelegten Regelfeder-Vorspannpositionen verstellbar ist, die einer höheren und einer niedrigeren Regelfeder-Vorspannung zugeordnet sind.Hydraulic control valve (R), in particular pressure-reducing valve or pressure-limiting valve, with a spring section (F) which contains a control spring (11) acting on a valve element (10), which is supported on a spring abutment (12), characterized in that the spring abutment ( 12) for changing the bias of the control spring (11) is selectively hydraulically adjustable between two mechanically fixed control spring bias positions, which are associated with a higher and a lower control spring bias. Hydraulik-Regelventil nach Anspruch 1, dadurch gekennzeichnet, dass das Federwiderlager (12) mittels eines zwischen zwei Anschlägen (21, 28) hin- und herbewegbaren Stellkolbens (13) hydraulisch verstellbar ist.Hydraulic control valve according to claim 1, characterized in that the spring abutment (12) by means of a between two stops (21, 28) back and forth movable actuating piston (13) is hydraulically adjustable. Hydraulik-Regelventil nach Anspruch 1, dadurch gekennzeichnet, dass zumindest ein Anschlag (21, 28) mechanisch einstellbar ist.Hydraulic control valve according to claim 1, characterized in that at least one stop (21, 28) is mechanically adjustable. Hydraulik-Regelventil nach Anspruch 1, dadurch gekennzeichnet, dass beide Anschläge (21, 28) mechanisch einstellbar sind.Hydraulic control valve according to claim 1, characterized in that both stops (21, 28) are mechanically adjustable. Hydraulik-Regelventil nach Anspruch 1, dadurch gekennzeichnet, dass das Federwiderlager (12) bei einem Ausfall, insbesondere Stromausfall, selbsttätig die Regelfeder-Vorspannposition für die höhere Regelfedervorspannung einnimmt.Hydraulic control valve according to claim 1, characterized in that the spring abutment (12) in case of failure, in particular power failure, automatically assumes the control spring biasing position for the higher control spring preload. Hydraulik-Regelventil nach Anspruch 1, dadurch gekennzeichnet, dass das Federwiderlager (12) bei einem Ausfall, insbesondere einem Stromausfall, selbsttätig die Regelfeder-Vorspannposition für die niedrigere Regelfeder-Vorspannung einnimmt.Hydraulic control valve according to claim 1, characterized in that the spring abutment (12) in case of failure, in particular a power failure, automatically assumes the control spring biasing position for the lower control spring bias. Hydraulik-Regelventil nach Anspruch 5, dadurch gekennzeichnet, dass das Federwiderlager (12) an einer im Stellkolben (13) festgelegten Zugstange (23) angeordnet ist, dass für den Stellkolben (13) der erste, der Regelfeder (11) und dem Ventilglied (10) zugewandte Anschlag (28) an einer Federhülse (18) angeordnet ist, die eine steifere Haltefeder (14) als die Regelfeder (11) enthält, wobei die Haltefeder (14) zwischen dem ersten Anschlag (28) und dem Federwiderlager (11) mit Vorspannung eingesetzt ist, und dass der zweite Anschlag (219 an der der Regelfeder (11) abgewandten Endseite der Zugstange (23) in der Federhülse (18) angeordnet ist.Hydraulic control valve according to claim 5, characterized in that the spring abutment (12) is arranged on a control piston (13) fixed tie rod (23) that for the actuating piston (13) of the first, the control spring (11) and the valve member ( 10) facing stop (28) on a spring sleeve (18) is arranged, which contains a stiffer retaining spring (14) than the control spring (11), wherein the retaining spring (14) between the first stop (28) and the spring abutment (11) is inserted with bias, and that the second stop (219 on the control spring (11) facing away from the end of the pull rod (23) in the spring sleeve (18) is arranged. Hydraulik-Regelventil nach Anspruch 7, dadurch gekennzeichnet, dass der Stellkolben (13) auf der Zugstange (23) durch ein Spannelement (22) festgelegt ist.Hydraulic control valve according to claim 7, characterized in that the adjusting piston (13) on the pull rod (23) by a clamping element (22) is fixed. Hydraulik-Regelventil nach Anspruch 7, dadurch gekennzeichnet, dass die Federhülse (18) mit dem Federwiderlager (11) in einem Außengehäuse (16) relativ zu einer im Außengehäuse (16) vorgegebenen Position (29) für die höchst mögliche Regelfeder-Vorspannung verschraubbar ist.Hydraulic control valve according to claim 7, characterized in that the spring sleeve (18) with the spring abutment (11) in an outer housing (16) relative to a in the outer housing (16) predetermined position (29) for the highest possible control spring bias voltage can be screwed , Hydraulik-Regelventil nach Anspruch 7, dadurch gekennzeichnet, dass der zweite Anschlag (21) an einem in der Federhülse verschraubbaren Schraubeinsatz (20) angeordnet ist.Hydraulic control valve according to claim 7, characterized in that the second stop (21) is arranged on a screwed into the spring sleeve screw insert (20). Hydraulik-Regelventil nach wenigstens einem der Ansprüche 9 und 10, dadurch gekennzeichnet, dass die Gewindebereiche (17, 19) abgedichtet sind.Hydraulic control valve according to at least one of claims 9 and 10, characterized in that the threaded portions (17, 19) are sealed. Hydraulik-Regelventil nach Anspruch 7, dadurch gekennzeichnet, dass in der Federhülse (18) beim ersten Anschlag (28) eine Steuerkammer (30) vorgesehen ist, in der sich der Stellkolben (13) befindet, und dass die Steuerkammer (30) über einen den Gewindebereich (17) zwischen der Federhülse und dem Außengehäuse durchsetzenden Kanal (27) mit einem Druckanschluss (26) des Außengehäuses (16) verbunden ist.Hydraulic control valve according to claim 7, characterized in that in the spring sleeve (18) at the first stop (28) a control chamber (30) is provided, in which the actuating piston (13) is located, and that the control chamber (30) via a the threaded portion (17) between the spring sleeve and the outer housing passing through channel (27) with a pressure port (26) of the outer housing (16) is connected. Hydraulik-Regelventil nach Anspruch 7, dadurch gekennzeichnet, dass der die Haltefeder (14) enthaltende Innenraum der Federhülse (18) mit einem Rücklaufanschluss (25) des Außengehäuses (16) verbunden ist.Hydraulic control valve according to claim 7, characterized in that the holding spring (14) containing the interior of the spring sleeve (18) with a return port (25) of the outer housing (16) is connected. Hydraulik-Regelventil nach Anspruch 7, dadurch gekennzeichnet, dass auf dem Außengehäuse (16) ein 3/2-Wege-Magnetsitzventil (8) angeordnet ist, das mit Versorgungsdruck speisbar ist, vorzugsweise über einen im Außengehäuse ausgebildeten, an einen Druckanschluss des Regelventils (R) angeschlossenen Versorgungskanal.Hydraulic control valve according to claim 7, characterized in that on the outer housing (16) a 3/2-way solenoid seat valve (8) is arranged, which can be fed with supply pressure, preferably via a formed in the outer housing, to a pressure port of the control valve ( R) connected supply channel. Hydraulik-Regelventil nach Anspruch 6, dadurch gekennzeichnet, dass das Federwiderlager (12) direkt mit dem Stellkolben (13) verbunden ist, der auf der der Regelfeder (11) abgewandten Seite in einer Steuerkammer (30) eines Zylinders (20) angeordnet ist, welcher den zweiten Anschlag (21) für die niedrigere Regelfedervorspannung definiert und in einer Anschlaghülse (18') verschraubbar ist, die den ersten Anschlag (28) für die höhere Regelfeder-Vorspannung definiert, und dass die Anschlaghülse (18') in einem Außengehäuse (16) verschraubbar ist.Hydraulic control valve according to claim 6, characterized in that the spring abutment (12) is directly connected to the actuating piston (13), which is arranged on the control spring (11) side facing away in a control chamber (30) of a cylinder (20), which defines the second control spring bias stop (21) and is threadable in a stop sleeve (18 ') defining the first control spring bias stop (28) and the stop sleeve (18') in an outer housing (18). 16) can be screwed. Elektrohydraulische Spannvorrichtung (S), insbesondere für eine Werkzeugmaschine, mit einem Spannzylinder (1), der über ein Richtungssteuerventil (4) an ein Regelventil (R) für den Spanndruck angeschlossen ist, welches eine an einem Federwiderlager (12) abgestützte Regelfeder (11) aufweist, dadurch gekennzeichnet, dass das Federwiderlager (12) des Regelventils (R) zur Änderung der Vorspannung der Regelfeder (11) wahlweise hydraulisch zwischen zwei mechanisch festgelegten Regelfeder-Vorspannpositionen verstellbar ist, die einer höheren und einer niedrigeren Regelfeder-Vorspannung zugeordnet sind, und dass zum Wählen der Regelfeder-Vorspannposition ein zum Regelventil (R) paralleles 3/2-Wege-Magnetventil (8) vorgesehen ist.Electrohydraulic tensioning device (S), in particular for a machine tool, having a clamping cylinder (1) which is connected via a directional control valve (4) to a control valve (R) for the clamping pressure, which has a control spring (11) supported on a spring abutment (12). characterized in that the spring abutment (12) of the control valve (R) for changing the bias of the control spring (11) is selectively hydraulically adjustable between two mechanically fixed control spring bias positions, which are associated with a higher and a lower control spring bias, and in that a 3/2-way solenoid valve (8) parallel to the control valve (R) is provided for selecting the control spring biasing position.
EP06016027A 2006-08-01 2006-08-01 Hydraulic control valve and electrohydraulic clamping device Expired - Fee Related EP1884853B1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
AT06016027T ATE422255T1 (en) 2006-08-01 2006-08-01 HYDRAULIC CONTROL VALVE AND ELECTROHYDRAULIC TENSIONING DEVICE
EP06016027A EP1884853B1 (en) 2006-08-01 2006-08-01 Hydraulic control valve and electrohydraulic clamping device
DE502006002776T DE502006002776D1 (en) 2006-08-01 2006-08-01 Hydraulic control valve and electro-hydraulic tensioning device

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Application Number Priority Date Filing Date Title
EP06016027A EP1884853B1 (en) 2006-08-01 2006-08-01 Hydraulic control valve and electrohydraulic clamping device

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3625222A1 (en) * 1986-07-25 1988-02-04 Index Werke Kg Hahn & Tessky PRESSURE REGULATOR FOR HYDRAULICALLY CONTROLLED MACHINE TOOLS
DE9310932U1 (en) * 1993-07-21 1993-09-30 Heilmeier & Weinlein Electro-hydraulic control device
DE29710127U1 (en) * 1997-06-10 1997-08-14 Heilmeier & Weinlein Electro-hydraulic clamping device
DE20208990U1 (en) * 2002-06-10 2003-10-23 Hawe Hydraulik Gmbh & Co Kg Electro-hydraulic clamping device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3625222A1 (en) * 1986-07-25 1988-02-04 Index Werke Kg Hahn & Tessky PRESSURE REGULATOR FOR HYDRAULICALLY CONTROLLED MACHINE TOOLS
DE9310932U1 (en) * 1993-07-21 1993-09-30 Heilmeier & Weinlein Electro-hydraulic control device
DE29710127U1 (en) * 1997-06-10 1997-08-14 Heilmeier & Weinlein Electro-hydraulic clamping device
DE20208990U1 (en) * 2002-06-10 2003-10-23 Hawe Hydraulik Gmbh & Co Kg Electro-hydraulic clamping device

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EP1884853B1 (en) 2009-02-04
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