EP1959146B1 - Electrohydraulic actuator device - Google Patents

Electrohydraulic actuator device Download PDF

Info

Publication number
EP1959146B1
EP1959146B1 EP20070123422 EP07123422A EP1959146B1 EP 1959146 B1 EP1959146 B1 EP 1959146B1 EP 20070123422 EP20070123422 EP 20070123422 EP 07123422 A EP07123422 A EP 07123422A EP 1959146 B1 EP1959146 B1 EP 1959146B1
Authority
EP
European Patent Office
Prior art keywords
drive device
piston
control piston
pressure
control
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.)
Not-in-force
Application number
EP20070123422
Other languages
German (de)
French (fr)
Other versions
EP1959146A2 (en
EP1959146A3 (en
Inventor
Jörg Dantlgraber
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.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Robert Bosch GmbH filed Critical Robert Bosch GmbH
Publication of EP1959146A2 publication Critical patent/EP1959146A2/en
Publication of EP1959146A3 publication Critical patent/EP1959146A3/en
Application granted granted Critical
Publication of EP1959146B1 publication Critical patent/EP1959146B1/en
Not-in-force legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

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
    • F15B9/00—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member
    • F15B9/02—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member with servomotors of the reciprocatable or oscillatable type
    • F15B9/08—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member with servomotors of the reciprocatable or oscillatable type controlled by valves affecting the fluid feed or the fluid outlet of the servomotor
    • F15B9/12—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member with servomotors of the reciprocatable or oscillatable type controlled by valves affecting the fluid feed or the fluid outlet of the servomotor in which both the controlling element and the servomotor control the same member influencing a fluid passage and are connected to that member by means of a differential gearing

Definitions

  • the invention relates to an electro-hydraulic drive device according to the preamble of patent claim 1.
  • the electrohydraulic drive device according to the invention can be used in principle in a variety of lifting and adjusting devices, for example, in the operation of a blow mandrel of a blow molding machine.
  • Such an electro-hydraulic drive device is for example from the DE 195 37 109 C2 known.
  • a hydraulic cylinder with a unilaterally protruding from a housing piston rod use is arranged at the lower free end of the mandrel.
  • To control the movement of the blowing mandrel designed as a rotary valve gate follow-up control valve with electromechanically controllable setpoint specification and mechanical position feedback feedback is provided.
  • the position command value input via a stepper motor, which can be controlled by output signals of an electronic control unit.
  • the position feedback is via a connected to the piston and the follower valve rack gear.
  • the piston rod of the working cylinder acts on a sliding slide member, with which the threaded spindle is connected, so that a displacement of the working piston causes a rectified displacement of the threaded spindle and compensates for the previously occurred opposing axial movement of the spindle nut.
  • a tracking control is achieved, in which the rotation of the electric motor is converted into a proportional feed movement of the displaceable slide member by means of the working cylinder.
  • the disadvantage of such a drive device is that it has a production-technically complex multi-part housing with a large space requirement.
  • the present invention seeks to provide an electro-hydraulic drive device that allows a linear movement of an actuating element with minimal device complexity.
  • the electro-hydraulic drive device has a cylinder housing, on which a control piston is guided, which is axially displaceable via an electric motor and cooperates with a control piston.
  • the control piston is at least partially guided within the actuating piston, wherein the control piston has at least two control edges over which a pressure medium connection between a portion of the actuator piston limited working space and a pressure medium source or a pressure medium sink or is zuu Kunststoffbar.
  • control piston is thus guided at least in sections within the actuating piston, so that compared to the prior art according to the DE 87 03 507 U1 a compact drive device is made possible with minimal device complexity.
  • the pressure medium connection between a control piston associated with the working space and a pressure medium source on the one hand or the working space and a pressure medium sink is open or closed via a control edge arrangement, so that over the prior art according to the DE 195 37 109 C2 no additional follower valve and no mechanical position feedback is required. As a result, an improved control of the actuating piston is possible.
  • a position detection system is associated with the electric motor, so that the position of the electric motor can be used as the actual value of the actuating piston position. If necessary, the position detection system is designed such that the position of the electric motor is completely detected over many revolutions.
  • the actuating piston defines with the cylinder housing in an embodiment of the invention connected to the pressure medium source effective in the extension direction pressure chamber.
  • the actuating piston has an annular groove in which an annular skirt of the cylinder housing dips and delimits the pressure chamber, while an immersed in a receiving bore of the cylinder housing inner part of the actuating piston with the control piston limits the working space.
  • the effective area assigned to the pressure chamber has a larger cross section than a working area of the actuating piston assigned to the working space and effective in the same direction.
  • control edges of the control piston and / or the control piston are formed on annular grooves or pockets.
  • the working space is preferably connectable via the control piston and a return channel in the cylinder housing with the pressure medium sink.
  • a high-pressure accumulator as the pressure medium source and a low-pressure accumulator as the pressure medium sink.
  • the high-pressure accumulator is preferably associated with at least one, for example, driven by a small electric motor charge pump, which ensures that the flowing over the control edges in the low-pressure accumulator pressure medium quantity is conveyed into the high-pressure accumulator and in this an approximately constant pressure is maintained.
  • the electro-hydraulic drive device preferably has a closed hydraulic circuit with lifetime filling.
  • the axial displacement of the control piston and thereby the pressure medium connection between the working space and the pressure medium source on the one hand or the working space and the pressure medium sink on the other hand can be controlled by a screw drive.
  • An axial displacement of the control piston is achieved by turning the screw by means of the electric motor.
  • the screw mechanism consists essentially of an adjusting sleeve, which is rotatably but axially displaceably received in the cylinder housing and is in operative connection with a threaded nut which is mounted axially fixed in the cylinder housing via thrust bearings and driven by the electric motor.
  • the control piston is supported via at least one prestressed spring on the screw drive.
  • the control piston has a spring chamber in which the at least one spring is arranged, which is supported with a first end on an inner surface of the control piston and with its second end to a spring plate and biases it against an inner wall of the control piston, wherein the spring plate via a protruding from the control piston connecting element, such as a rod, is connected to a setting sleeve of the screw drive.
  • control piston is movable when the spring bias is exceeded against the force of the spring along the connecting element.
  • the invention will be explained in more detail below with reference to a preferred embodiment.
  • the single figure shows a schematic representation of an electro-hydraulic drive device according to the invention.
  • This electro-hydraulic drive device 1 has a cylinder housing 2, in whose trained as a stepped bore receiving bore 4, a control piston 6 is guided, which is axially displaceable by means of an electric motor 8 and cooperates with a control piston 10.
  • the actuating piston 10 has an annular groove 32 in which an annular jacket 34 of the cylinder housing 2 dips and limits an effective in the extension direction pressure chamber 36, while a dipping into the receiving bore 4 inner part 38 of the actuating piston 10 with the control piston 6 an effective also in the extension direction working space 20 is limited, wherein the pressure chamber 36 associated active surface 39 has a larger cross section than the working space 20 associated and effective in the same direction effective surface 41 of the actuating piston 10.
  • the annular groove 32 and thus the pressure chamber 36 are sealed relative to the annular jacket 34 by a seal 40 inserted in these outwardly.
  • the pressure chamber 36 is connected via a supply channel 42 with a pressure medium source 22 and via a connecting channel 44 with an upper annular groove 26 of the actuating piston 10.
  • the working space 20 is connected via a pressure medium channel 46 with an annular groove 28 of the control piston 10.
  • This has a discharge channel 48, which opens in the illustrated equilibrium position of the drive device 1 in a lower annular groove 30 of the actuating piston 10.
  • the lower annular groove 30 is connected via a through bore 50 with an annular groove 52 of the cylinder housing 2, which is connected via a return passage 54 of the cylinder housing 2 and a return line 56 to a pressure medium sink 24.
  • a pressure medium source 22 is in the illustrated embodiment, a high-pressure accumulator and a pressure medium sink 24, a low-pressure accumulator use.
  • the high-pressure accumulator 22 is associated with a driven by a small electric motor 58 charge pump 60, the pressure medium on the Return line 56 from the low-pressure accumulator 24 promotes and supplies via a pump line 62 to the high-pressure accumulator 22.
  • the charge pump 60 ensures that the amount of pressure medium flowing into the low pressure accumulator 24 is conveyed into the high pressure accumulator 22 and this has a constant pressure.
  • the electro-hydraulic drive device 1 has a closed hydraulic circuit with lifetime filling, so that a minimum of maintenance is guaranteed.
  • the control piston 6 is guided in sections within the actuating piston 10 and has on the annular groove 28 two axially spaced control edges 12, 14 which cooperate with control edges 16, 18 at the annular grooves 26, 30 of the actuating piston 6, so that a pressure medium connection between the working space 20th and the pressure medium source 22 or the working space 20 and the pressure medium sink 24 or is zuu Kunststoffbar.
  • a compact drive device 1 is made possible with minimal outlay on apparatus. Since the pressure medium connection between the working chamber 20 and the pressure medium source 22 on the one hand or the working space 20 and the pressure medium sink 24 via the control edges 12, 14, 16, 18 open or closed, no additional follower valve and no mechanical position feedback is required.
  • control edges 12, 14, 16, 18 of the actuating piston 10 and the control piston 6 are each formed by the circumferential annular grooves 26, 28, 30.
  • the axial displacement of the control piston 6 via a driven by the electric motor 8 screw 64 is associated with a not shown position detection system, so that the position of the electric motor 8 is used as the actual value of the actuating piston position.
  • the screw 64 essentially consists of a control sleeve 66, the rotatably but axially slidably received in a receiving space 68 of the cylinder housing 2 and is connected via an external thread 70 with a threaded nut 72 in operative connection.
  • the receiving space 68 is sealed off from the working space 20 by means of a seal 74.
  • the threaded nut 72 is mounted on both sides via thrust bearings 76, 78 in the cylinder housing 2 and is driven by a toothed belt 80, which meshes with a drive wheel 82 of the electric motor 8.
  • An axial displacement of the control piston 10 is achieved by turning the screw 64 by means of the electric motor 8, which converts the rotational movement of the electric motor 8 in an axial movement of the adjusting sleeve 66 and thereby of the control piston 10 relative to the cylinder housing 2.
  • this is arranged with axial clearance in the receiving space 68.
  • a passage opening 84 is provided in the cylinder housing 2 for the adjusting sleeve 66 below the adjusting sleeve 66.
  • control piston 6 is supported on the screw drive 64 via a prestressed compression spring 86.
  • the control piston 10 has a spring chamber 88, in which the compression spring 86 is arranged, which is supported with a first end on an inner surface 90 of the control piston 6 and with its second end to a spring plate 92 and biases it against an inner wall 94 of the control piston 6.
  • the spring plate 92 is connected via a guided in a through hole 96 of the control piston 10 rod 98 as a connecting element with the adjusting sleeve 66 of the screw 64, wherein the control piston 6 when the spring bias is exceeded against the force of the compression spring 86 along the rod 98 is movable.
  • the annular grooves 26, 30 of the actuating piston 10 are covered by the outer peripheral wall 100 of the control piston 6, wherein the upper control edge 16 of the actuating piston 10 above and the lower control edge 18 of the actuating piston 10 below the annular groove 28 of the control piston 6 is located.
  • the pressure medium connection is interrupted by the pressure chamber 36 and thus by the high pressure accumulator 22 in the working space 20 and the connection from the working space 20 to the low pressure accumulator 24.
  • the high-pressure accumulator 22 is connected via the supply channel 42 to the pressure chamber 36.
  • the space 102 above the control piston 6 is connected via the discharge channel 48, the annular groove 30 of the actuating piston 10, the through hole 50 and the annular groove 52 of the cylinder housing 2 via the return passage 54 to the low-pressure storage 24.
  • the effective area 39 bounding the pressure chamber 36 of the actuating piston 10 is pressurized in such a way that essentially a weight compensation of the mass to be moved takes place.
  • about 60 to 80% of the load on the adjusting piston 10 weight force of the pressure force on the active surface 39 of the pressure chamber 36 and the rest by the pressure force on the active surface 41 of the working space 20 is added.
  • the electric motor 8 is actuated, which drives the threaded nut 72 via the drive wheel 82 and the toothed belt 80, which is connected via an internal thread 104 with the rotatably but axially displaceably received in the receiving space 68 of the cylinder housing 2 actuating sleeve 66 in operative connection.
  • the threaded nut 72 is mounted on both sides via the thrust bearings 76, 78 in the cylinder housing 2, so that the screw 64 converts the rotational movement of the electric motor 8 in an axial movement of the adjusting sleeve 66 relative to the cylinder housing 2.
  • control piston 6 Since the control piston 6 is supported by the preloaded compression spring 86 on the screw 64, this is in the one direction of rotation of the electric motor 8 according to the Axial movement of the adjusting sleeve 66 is shifted upward, wherein the pressure medium connection is controlled by the pressure chamber 36 of the actuating piston 10 via the control edge 12 of the control piston 6 to the annular groove 28 of the control piston 6 and at the same time via the control edge 14 of the control piston 6 the connection to the low-pressure accumulator 24 is controlled.
  • the actuating piston 10 moves upward until the pressure medium connection to the working chamber 20 is interrupted via the control edge 16 of the actuating piston 10.
  • the actuating piston 10 moves by the same distance as the control piston 6 upwards, wherein the adjusting movement of the movement of the electric motor 8 corresponds, so that the adjusting movement of the electric motor is used as the actual value of the actuating piston position.
  • the control piston 6 can move against the force of the prestressed compression spring 86 relative to the adjusting sleeve 66, so that impact forces are reduced to the drive to a minimum.
  • the electric motor 8 is driven in the opposite direction and the control piston 6 moves downward. This opens a flow cross-section between the control edges 14 and 18.
  • the load pressure fluid is displaced from the working space 20 in the low pressure accumulator 24.
  • the actuating piston 10 thus follows the control piston 6 down until the flow cross-section between the control edges 14 and 18 is closed again.
  • an electro-hydraulic drive device with a cylinder housing 2 on which a control piston 6 is guided, which is axially displaceable via an electric motor 8 and cooperates with a control piston 10.
  • the control piston 6 is at least partially guided within the actuating piston 10, wherein the control piston 6 at least two control edges 12, 14, via a pressure medium connection between a part of the control piston 10 partially limited working space 20 and a pressure medium source 22 or a pressure medium sink 24 up or steered is.

Description

Die Erfindung betrifft eine elektrohydraulische Antriebseinrichtung gemäß dem Oberbegriff des Patentanspruchs 1.The invention relates to an electro-hydraulic drive device according to the preamble of patent claim 1.

Die erfindungsgemäße elektrohydraulische Antriebseinrichtung kann prinzipiell bei einer Vielzahl von Hub- und Stelleinrichtungen, beispielsweise bei der Betätigung eines Blasdorns einer Blasformmaschine eingesetzt werden.The electrohydraulic drive device according to the invention can be used in principle in a variety of lifting and adjusting devices, for example, in the operation of a blow mandrel of a blow molding machine.

Eine derartige elektrohydraulische Antriebseinrichtung ist beispielsweise aus der DE 195 37 109 C2 bekannt. Bei dieser herkömmlichen Antriebseinrichtung zur Steuerung der Vorschub-und Rückzugsbewegung des Blasdornes einer Blasformmaschine findet ein Hydrozylinder mit einer einseitig aus einem Gehäuse herausragenden Kolbenstange Verwendung, an deren unterem freien Ende der Blasdorn angeordnet ist. Zur Bewegungssteuerung des Blasdorns ist ein als Drehschieberventil ausgebildetes Nachlaufregelventil mit elektromechanisch steuerbarer SollwertVorgabe sowie mechanischer Positions-Istwert-Rückmeldung vorgesehen. Die Positions-Sollwertvorgabe erfolgt über einen Schrittmotor, der durch Ausgangssignale einer elektronischen Steuereinheit ansteuerbar ist. Die Positionsrückmeldung erfolgt über ein mit dem Kolben und dem Nachlaufregelventil verbundenes Zahnstangengetriebe. Durch den Kolben sind zwei Arbeitsräume voneinander getrennt, denen unterschiedlich große Kolbenflächen zugeordnet sind, wobei der Arbeitsraum der kleineren Kolbenfläche permanent mit dem Pumpenanschluss des Druckversorgungsaggregats verbunden ist und die Hubbewegungen des Blasdorns durch Druckeinkopplung in den anderen, der größeren Kolbenfläche zugeordneten Arbeitsraum des Hydrozylinders erfolgt. Nachteilig bei derartigen Antriebseinrichtungen ist zum Einen, dass die Vorsteuerung aufgrund des Drehschieberventils äußerst aufwendig ist und hohe Leckageverluste aufweist, und zum Anderen, dass ein Zahnstangengetriebe zur Positionsrückmeldung erforderlich ist, das mit dem Drehschieberventil in Wirkverbindung steht, so dass die Positionserfassung fertigungstechnisch aufwendig ist. Des Weiteren ist nachteilig, dass zur Versorgung des Hydrozylinders ein aufwendiges Hydraulikaggregat erforderlich ist.Such an electro-hydraulic drive device is for example from the DE 195 37 109 C2 known. In this conventional drive device for controlling the advancing and retracting movement of the mandrel of a blow molding machine, a hydraulic cylinder with a unilaterally protruding from a housing piston rod use, is arranged at the lower free end of the mandrel. To control the movement of the blowing mandrel designed as a rotary valve gate follow-up control valve with electromechanically controllable setpoint specification and mechanical position feedback feedback is provided. The position command value input via a stepper motor, which can be controlled by output signals of an electronic control unit. The position feedback is via a connected to the piston and the follower valve rack gear. By the piston two working spaces are separated from each other, which are associated with different sized piston surfaces, the working space of the smaller piston surface is permanently connected to the pump port of the pressure supply unit and the strokes of the mandrel by pressure injection into the other, the larger piston surface associated working space of the hydraulic cylinder takes place. A disadvantage of such drive means is on the one hand, that the pilot control is extremely expensive due to the rotary valve and has high leakage losses, and the Others that a rack and pinion gear for position feedback is required, which is in operative connection with the rotary valve, so that the position detection is manufacturing technology consuming. Furthermore, it is disadvantageous that a complex hydraulic unit is required to supply the hydraulic cylinder.

Zur Verringerung der Leckageverluste ist aus der DE 87 03 507 U1 (Basis für den Oberbegriff des Anspruchs 1) ein Vorschubantrieb für einen linear verschiebbaren Werkzeugschlitten bekannt, bei dem über einen Elektromotor eine Gewindespindel angetrieben wird, die in Eingriff mit einer Spindelmutter steht, so dass sich die Spindelmutter bei einer Drehbewegung der Gewindespindel in axialer Richtung verschiebt. Die Spindelmutter ist in einer Hülse geführt und mit Steuerkanten versehen die mit Steuerkanten der Hülse zusammenwirken und die Druckmittelverbindung zu Druckräumen eines achsparallel zu der Gewindespindel angeordneten Arbeitszylinders steuern. Die Kolbenstange des Arbeitszylinders wirkt auf ein verschiebbares Schlittenteil, mit dem auch die Gewindespindel verbunden ist, so dass eine Verschiebung des Arbeitskolbens eine gleichgerichtete Verschiebung der Gewindespindel bewirkt und die vorher stattgefundene entgegengerichtete axiale Bewegung der Spindelmutter ausgleicht. Dadurch wird eine Nachlauf-regelung erreicht, bei der die Drehung des Elektromotors in eine proportionale Vorschubbewegung des verschiebbaren Schlittenteils mittels des Arbeitszylinders umgewandelt wird. Nachteilig bei einer derartigen Antriebsvorrichtung ist, dass diese ein fertigungstechnisch aufwendiges mehrteiliges Gehäuse mit großem Bauraumbedarf aufweist.To reduce the leakage losses is from the DE 87 03 507 U1 (Basis for the preamble of claim 1) a feed drive for a linearly displaceable tool carriage known in which via an electric motor, a threaded spindle is driven, which is in engagement with a spindle nut, so that the spindle nut shifts in a rotational movement of the threaded spindle in the axial direction , The spindle nut is guided in a sleeve and provided with control edges which cooperate with control edges of the sleeve and control the pressure medium connection to pressure chambers of an axially parallel to the threaded spindle arranged working cylinder. The piston rod of the working cylinder acts on a sliding slide member, with which the threaded spindle is connected, so that a displacement of the working piston causes a rectified displacement of the threaded spindle and compensates for the previously occurred opposing axial movement of the spindle nut. As a result, a tracking control is achieved, in which the rotation of the electric motor is converted into a proportional feed movement of the displaceable slide member by means of the working cylinder. The disadvantage of such a drive device is that it has a production-technically complex multi-part housing with a large space requirement.

Demgegenüber liegt der Erfindung die Aufgabe zugrunde, eine elektrohydraulische Antriebseinrichtung zu schaffen, die eine lineare Bewegung eines Stellelements bei minimalem vorrichtungstechnischen Aufwand ermöglicht.In contrast, the present invention seeks to provide an electro-hydraulic drive device that allows a linear movement of an actuating element with minimal device complexity.

Diese Aufgabe wird durch eine elektrohydraulische Antriebseinrichtung mit den Merkmalen des Patentanspruchs 1 gelöst.This object is achieved by an electro-hydraulic drive device with the features of patent claim 1.

Die erfindungsgemäße elektrohydraulische Antriebseinrichtung hat ein Zylindergehäuse, an dem ein Steuerkolben geführt ist, der über einen Elektromotor axial verschiebbar ist und mit einem Stellkolben zusammenwirkt. Erfindungsgemäß ist der Steuerkolben zumindest abschnittsweise innerhalb des Stellkolbens geführt, wobei der Steuerkolben mindestens zwei Steuerkanten aufweist, über die eine Druckmittelverbindung zwischen einem vom Stellkolben abschnittsweise begrenzten Arbeitsraum und einer Druckmittelquelle oder einer Druckmittelsenke auf- oder zusteuerbar ist.The electro-hydraulic drive device according to the invention has a cylinder housing, on which a control piston is guided, which is axially displaceable via an electric motor and cooperates with a control piston. According to the invention, the control piston is at least partially guided within the actuating piston, wherein the control piston has at least two control edges over which a pressure medium connection between a portion of the actuator piston limited working space and a pressure medium source or a pressure medium sink or is zuusteuerbar.

Bei der erfindungsgemäßen Lösung ist der Steuerkolben somit zumindest abschnittsweise innerhalb des Stellkolbens geführt, so dass gegenüber dem Stand der Technik gemäß der DE 87 03 507 U1 eine kompakte Antriebsvorrichtung bei minimalem vorrichtungstechnischen Aufwand ermöglicht ist. Die Druckmittelverbindung zwischen einem dem Stellkolben zugeordneten Arbeitsraum und einer Druckmittelquelle einerseits oder dem Arbeitsraum und einer Druckmittelsenke wird über eine Steuerkantenanordnung auf- oder zugesteuert, so dass gegenüber dem Stand der Technik gemäß der DE 195 37 109 C2 kein zusätzliches Nachlaufventil und keine mechanische Positionsrückführung erforderlich ist. Dadurch ist eine verbesserte Ansteuerung des Stellkolbens ermöglicht.In the solution according to the invention, the control piston is thus guided at least in sections within the actuating piston, so that compared to the prior art according to the DE 87 03 507 U1 a compact drive device is made possible with minimal device complexity. The pressure medium connection between a control piston associated with the working space and a pressure medium source on the one hand or the working space and a pressure medium sink is open or closed via a control edge arrangement, so that over the prior art according to the DE 195 37 109 C2 no additional follower valve and no mechanical position feedback is required. As a result, an improved control of the actuating piston is possible.

Gemäß einem besonders bevorzugten Ausführungsbeispiel der Erfindung ist dem Elektromotor ein Positionserfassungssystem zugeordnet, so dass die Position des Elektromotors als Istwert der Stellkolbenposition verwendbar ist. Falls notwendig, ist das Positionserfassungssystem derart ausgebildet, dass die Position des Elektromotors über viele Umdrehungen hinweg absolut erfasst ist.According to a particularly preferred embodiment of the invention, a position detection system is associated with the electric motor, so that the position of the electric motor can be used as the actual value of the actuating piston position. If necessary, the position detection system is designed such that the position of the electric motor is completely detected over many revolutions.

Der Stellkolben begrenzt mit dem Zylindergehäuse bei einem erfindungsgemäßen Ausführungsbeispiel einen mit der Druckmittelquelle verbundenen in Ausfahrrichtung wirksamen Druckraum.The actuating piston defines with the cylinder housing in an embodiment of the invention connected to the pressure medium source effective in the extension direction pressure chamber.

Bei einer besonders kompakten Ausführung der Antriebseinrichtung hat der Stellkolben eine Ringnut, in die ein Ringmantel des Zylindergehäuses eintaucht und den Druckraum begrenzt, während ein in eine Aufnahmebohrung des Zylindergehäuses eintauchendes Innenteil des Stellkolbens mit dem Steuerkolben den Arbeitsraum begrenzt.In a particularly compact design of the drive device, the actuating piston has an annular groove in which an annular skirt of the cylinder housing dips and delimits the pressure chamber, while an immersed in a receiving bore of the cylinder housing inner part of the actuating piston with the control piston limits the working space.

Die dem Druckraum zugeordnete Wirkfläche hat bei einer bevorzugten Ausführung der Erfindung einen größeren Querschnitt als eine dem Arbeitsraum zugeordnete und in gleicher Richtung wirksame Wirkfläche des Stellkolbens.In a preferred embodiment of the invention, the effective area assigned to the pressure chamber has a larger cross section than a working area of the actuating piston assigned to the working space and effective in the same direction.

Als fertigungstechnisch besonders vorteilhaft hat es sich erwiesen, wenn die Steuerkanten des Stellkolbens und/oder des Steuerkolbens an Ringnuten oder Taschen ausgebildet sind.As a manufacturing technology, it has proven particularly advantageous if the control edges of the control piston and / or the control piston are formed on annular grooves or pockets.

Der Arbeitsraum ist vorzugsweise über den Steuerkolben und einen Rücklaufkanal im Zylindergehäuse mit der Druckmittelsenke verbindbar.The working space is preferably connectable via the control piston and a return channel in the cylinder housing with the pressure medium sink.

Erfindungsgemäß wird es bevorzugt, einen Hochdruckspeicher als Druckmittelquelle und einen Niederdruckspeicher als Druckmittelsenke zu verwenden. Dem Hochdruckspeicher ist vorzugsweise zumindest eine, beispielsweise von einem kleinen Elektromotor angetriebene Ladepumpe zugeordnet, die dafür sorgt, dass die über die Steuerkanten in den Niederdruckspeicher fließende Druckmittelmenge in den Hochdruckspeicher gefördert wird und in diesem ein etwa konstanter Druck gehalten wird. Die elektrohydraulische Antriebseinrichtung hat vorzugsweise einen geschlossenen Hydraulikkreis mit Lebensdauerfüllung.According to the invention, it is preferred to use a high-pressure accumulator as the pressure medium source and a low-pressure accumulator as the pressure medium sink. The high-pressure accumulator is preferably associated with at least one, for example, driven by a small electric motor charge pump, which ensures that the flowing over the control edges in the low-pressure accumulator pressure medium quantity is conveyed into the high-pressure accumulator and in this an approximately constant pressure is maintained. The electro-hydraulic drive device preferably has a closed hydraulic circuit with lifetime filling.

Die Axialverschiebung des Steuerkolbens und dadurch die Druckmittelverbindung zwischen dem Arbeitsraum und der Druckmittelquelle einerseits oder dem Arbeitsraum und der Druckmittelsenke andererseits ist über einen Gewindetrieb steuerbar. Eine axiale Verschiebung des Steuerkolbens wird durch Drehen des Gewindetriebes mittels des Elektromotors erreicht. Der Gewindetrieb besteht im Wesentlichen aus einer Stellhülse, die drehfest aber axial verschiebbar in dem Zylindergehäuse aufgenommen ist und mit einer Gewindemutter in Wirkverbindung steht, die über Axiallager in dem Zylindergehäuse axialfest gelagert und mittels des Elektromotors angetrieben ist.The axial displacement of the control piston and thereby the pressure medium connection between the working space and the pressure medium source on the one hand or the working space and the pressure medium sink on the other hand can be controlled by a screw drive. An axial displacement of the control piston is achieved by turning the screw by means of the electric motor. The screw mechanism consists essentially of an adjusting sleeve, which is rotatably but axially displaceably received in the cylinder housing and is in operative connection with a threaded nut which is mounted axially fixed in the cylinder housing via thrust bearings and driven by the electric motor.

Um bei einem Druckabfall des hydraulischen Systems eine Beschädigung des Antriebs zu vermeiden, ist der Steuerkolben über zumindest eine vorgespannte Feder an dem Gewindetrieb abgestützt. Vorzugsweise weist der Steuerkolben einen Federraum auf, in dem die zumindest eine Feder angeordnet ist, die sich mit einem ersten Ende an einer Innenfläche des Steuerkolbens und mit ihrem zweiten Ende an einem Federteller abstützt und diesen gegen eine Innenwandung des Steuerkolbens vorspannt, wobei der Federteller über ein aus dem Steuerkolben auskragendes Verbindungselement, beispielsweise eine Stange, mit einer Stellhülse des Gewindetriebs verbunden ist.In order to avoid damage to the drive at a pressure drop of the hydraulic system, the control piston is supported via at least one prestressed spring on the screw drive. Preferably, the control piston has a spring chamber in which the at least one spring is arranged, which is supported with a first end on an inner surface of the control piston and with its second end to a spring plate and biases it against an inner wall of the control piston, wherein the spring plate via a protruding from the control piston connecting element, such as a rod, is connected to a setting sleeve of the screw drive.

Dabei wird es besonders bevorzugt, wenn der Steuerkolben bei Überschreiten der Federvorspannung gegen die Kraft der Feder entlang des Verbindungselements bewegbar ist.It is particularly preferred if the control piston is movable when the spring bias is exceeded against the force of the spring along the connecting element.

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

Nachstehend wird die Erfindung anhand eines bevorzugten Ausführungsbeispiels näher erläutert. Die einzige Figur zeigt eine schematische Darstellung einer erfindungsgemäßen elektrohydraulischen Antriebseinrichtung.The invention will be explained in more detail below with reference to a preferred embodiment. The single figure shows a schematic representation of an electro-hydraulic drive device according to the invention.

Diese elektrohydraulische Antriebseinrichtung 1 besitzt ein Zylindergehäuse 2, in dessen als Stufenbohrung ausgebildeter Aufnahmebohrung 4 ein Steuerkolben 6 geführt ist, der mittels eines Elektromotors 8 axial verschiebbar ist und mit einem Stellkolben 10 zusammenwirkt. Bei der dargestellten besonders kompakten Ausführung der Antriebseinrichtung 1 hat der Stellkolben 10 eine Ringnut 32, in die ein Ringmantel 34 des Zylindergehäuses 2 eintaucht und einen in Ausfahrrichtung wirksamen Druckraum 36 begrenzt, während ein in die Aufnahmebohrung 4 eintauchendes Innenteil 38 des Stellkolbens 10 mit dem Steuerkolben 6 einen ebenfalls in Ausfahrrichtung wirksamen Arbeitsraum 20 begrenzt, wobei eine dem Druckraum 36 zugeordnete Wirkfläche 39 einen größeren Querschnitt als eine dem Arbeitsraum 20 zugeordnete und in gleicher Richtung wirksame Wirkfläche 41 des Stellkolbens 10 aufweist. Die Ringnut 32 und damit der Druckraum 36 sind gegenüber dem Ringmantel 34 durch eine in diesen eingesetzte Dichtung 40 nach außen hin abgedichtet. Der Druckraum 36 ist über einen Versorgungskanal 42 mit einer Druckmittelquelle 22 und über einen Verbindungskanal 44 mit einer oberen Ringnut 26 des Stellkolbens 10 verbunden. Der Arbeitsraum 20 ist über einen Druckmittelkanal 46 mit einer Ringnut 28 des Steuerkolbens 10 verbunden. Dieser hat einen Entlastungskanal 48, der in der dargestellten Gleichgewichtsstellung der Antriebseinrichtung 1 in eine untere Ringnut 30 des Stellkolbens 10 mündet. Die untere Ringnut 30 ist über eine Durchgangsbohrung 50 mit einer Ringnut 52 des Zylindergehäuses 2 verbunden, die über einen Rück-laufkanal 54 des Zylindergehäuses 2 und eine Rücklaufleitung 56 mit einer Druckmittelsenke 24 verbunden ist. Zwischen den Ringnuten 26, 30 und der Ringnut 28 besteht eine Nullüberdeckung oder eine relativ kleine positive Überdeckung. Als Druckmittelquelle 22 findet bei dem dargestellten Ausführungsbeispiel ein Hochdruckspeicher und als Druckmittelsenke 24 ein Niederdruckspeicher Verwendung. Dem Hochdruckspeicher 22 ist eine von einem kleinen Elektromotor 58 angetriebene Ladepumpe 60 zugeordnet, die Druckmittel über die Rücklaufleitung 56 aus dem Niederdruckspeicher 24 fördert und über eine Pumpenleitung 62 dem Hochdruckspeicher 22 zuführt. Die Ladepumpe 60 sorgt dafür, dass die in den Niederdruckspeicher 24 fließende Druckmittelmenge in den Hochdruckspeicher 22 gefördert wird und dieser einen konstanten Druck aufweist. Dadurch hat die elektrohydraulische Antriebseinrichtung 1 einen geschlossenen Hydraulikkreis mit Lebensdauerfüllung, so dass ein minimaler Wartungsaufwand gewährleistet ist.This electro-hydraulic drive device 1 has a cylinder housing 2, in whose trained as a stepped bore receiving bore 4, a control piston 6 is guided, which is axially displaceable by means of an electric motor 8 and cooperates with a control piston 10. In the illustrated particularly compact design of the drive device 1, the actuating piston 10 has an annular groove 32 in which an annular jacket 34 of the cylinder housing 2 dips and limits an effective in the extension direction pressure chamber 36, while a dipping into the receiving bore 4 inner part 38 of the actuating piston 10 with the control piston 6 an effective also in the extension direction working space 20 is limited, wherein the pressure chamber 36 associated active surface 39 has a larger cross section than the working space 20 associated and effective in the same direction effective surface 41 of the actuating piston 10. The annular groove 32 and thus the pressure chamber 36 are sealed relative to the annular jacket 34 by a seal 40 inserted in these outwardly. The pressure chamber 36 is connected via a supply channel 42 with a pressure medium source 22 and via a connecting channel 44 with an upper annular groove 26 of the actuating piston 10. The working space 20 is connected via a pressure medium channel 46 with an annular groove 28 of the control piston 10. This has a discharge channel 48, which opens in the illustrated equilibrium position of the drive device 1 in a lower annular groove 30 of the actuating piston 10. The lower annular groove 30 is connected via a through bore 50 with an annular groove 52 of the cylinder housing 2, which is connected via a return passage 54 of the cylinder housing 2 and a return line 56 to a pressure medium sink 24. Between the annular grooves 26, 30 and the annular groove 28 there is a zero overlap or a relatively small positive overlap. As a pressure medium source 22 is in the illustrated embodiment, a high-pressure accumulator and a pressure medium sink 24, a low-pressure accumulator use. The high-pressure accumulator 22 is associated with a driven by a small electric motor 58 charge pump 60, the pressure medium on the Return line 56 from the low-pressure accumulator 24 promotes and supplies via a pump line 62 to the high-pressure accumulator 22. The charge pump 60 ensures that the amount of pressure medium flowing into the low pressure accumulator 24 is conveyed into the high pressure accumulator 22 and this has a constant pressure. As a result, the electro-hydraulic drive device 1 has a closed hydraulic circuit with lifetime filling, so that a minimum of maintenance is guaranteed.

Der Steuerkolben 6 ist abschnittsweise innerhalb des Stellkolbens 10 geführt und weist an der Ringnut 28 zwei axial beabstandete Steuerkanten 12, 14 auf, die mit Steuerkanten 16, 18 an den Ringnuten 26, 30 des Stellkolbens 6 zusammenwirken, so dass eine Druckmittelverbindung zwischen dem Arbeitsraum 20 und der Druckmittelquelle 22 oder dem Arbeitsraum 20 und der Druckmittelsenke 24 auf- oder zusteuerbar ist. Aufgrund des abschnittsweise innerhalb des Stellkolbens 10 geführten Steuerkolbens 6 wird eine kompakte Antriebseinrichtung 1 bei minimalem vorrichtungstechnischen Aufwand ermöglicht. Da die Druckmittelverbindung zwischen dem Arbeitsraum 20 und der Druckmittelquelle 22 einerseits oder dem Arbeitsraum 20 und der Druckmittelsenke 24 über die Steuerkanten 12, 14, 16, 18 auf-oder zugesteuert wird, ist kein zusätzliches Nachlaufventil und keine mechanische Positionsrückführung erforderlich. Dadurch ist eine verbesserte Ansteuerung des Stellkolbens 10 ermöglicht. Als fertigungstechnisch besonders vorteilhaft hat es sich erwiesen, wenn die Steuerkanten 12, 14, 16, 18 des Stellkolbens 10 und des Steuerkolbens 6 jeweils durch die umlaufenden Ringnuten 26, 28, 30 ausgebildet sind.The control piston 6 is guided in sections within the actuating piston 10 and has on the annular groove 28 two axially spaced control edges 12, 14 which cooperate with control edges 16, 18 at the annular grooves 26, 30 of the actuating piston 6, so that a pressure medium connection between the working space 20th and the pressure medium source 22 or the working space 20 and the pressure medium sink 24 or is zuusteuerbar. As a result of the control piston 6 guided in sections within the actuating piston 10, a compact drive device 1 is made possible with minimal outlay on apparatus. Since the pressure medium connection between the working chamber 20 and the pressure medium source 22 on the one hand or the working space 20 and the pressure medium sink 24 via the control edges 12, 14, 16, 18 open or closed, no additional follower valve and no mechanical position feedback is required. As a result, an improved control of the actuating piston 10 is made possible. As a manufacturing technology, it has proven particularly advantageous if the control edges 12, 14, 16, 18 of the actuating piston 10 and the control piston 6 are each formed by the circumferential annular grooves 26, 28, 30.

Die Axialverschiebung des Steuerkolbens 6 erfolgt über einen von dem Elektromotor 8 angetriebenen Gewindetrieb 64. Dem Elektromotor 8 ist ein nicht dargestelltes Positionserfassungssystem zugeordnet, so dass die Position des Elektromotors 8 als Istwert der Stellkolbenposition verwendbar ist. Der Gewindetrieb 64 besteht im Wesentlichen aus einer Stellhülse 66, die drehfest aber axial verschiebbar in einem Aufnahmeraum 68 des Zylindergehäuses 2 aufgenommen ist und über ein Außengewinde 70 mit einer Gewindemutter 72 in Wirkverbindung steht. Der Aufnahmeraum 68 ist mittels einer Dichtung 74 gegenüber dem Arbeitsraum 20 abgedichtet. Die Gewindemutter 72 ist beidseitig über Axiallager 76, 78 in dem Zylindergehäuse 2 gelagert und wird über einen Zahnriemen 80, der mit einem Antriebsrad 82 kämmt von dem Elektromotor 8 angetrieben. Eine axiale Verschiebung des Steuerkolbens 10 wird durch Drehen des Gewindetriebs 64 mittels des Elektromotors 8 erreicht, der die Drehbewegung des Elektromotors 8 in eine Axialbewegung der Stellhülse 66 und dadurch des Steuerkolbens 10 relativ zu dem Zylindergehäuse 2 umwandelt. Um eine Axialverschiebung der Stellhülse 66 in dem Zylindergehäuse 2 zu ermöglichen ist diese mit Axialspiel in dem Aufnahmeraum 68 angeordnet. Des Weiteren ist unterhalb der Stellhülse 66 eine Durchgangsöffnung 84 in dem Zylindergehäuse 2 für die Stellhülse 66 vorgesehen.The axial displacement of the control piston 6 via a driven by the electric motor 8 screw 64. The electric motor 8 is associated with a not shown position detection system, so that the position of the electric motor 8 is used as the actual value of the actuating piston position. The screw 64 essentially consists of a control sleeve 66, the rotatably but axially slidably received in a receiving space 68 of the cylinder housing 2 and is connected via an external thread 70 with a threaded nut 72 in operative connection. The receiving space 68 is sealed off from the working space 20 by means of a seal 74. The threaded nut 72 is mounted on both sides via thrust bearings 76, 78 in the cylinder housing 2 and is driven by a toothed belt 80, which meshes with a drive wheel 82 of the electric motor 8. An axial displacement of the control piston 10 is achieved by turning the screw 64 by means of the electric motor 8, which converts the rotational movement of the electric motor 8 in an axial movement of the adjusting sleeve 66 and thereby of the control piston 10 relative to the cylinder housing 2. In order to allow an axial displacement of the adjusting sleeve 66 in the cylinder housing 2, this is arranged with axial clearance in the receiving space 68. Furthermore, a passage opening 84 is provided in the cylinder housing 2 for the adjusting sleeve 66 below the adjusting sleeve 66.

Um bei Druckabfall des hydraulischen Systems eine Beschädigung des Antriebssystems zu vermeiden, ist der Steuerkolben 6 über eine vorgespannte Druckfeder 86 an dem Gewindetrieb 64 abgestützt. Der Steuerkolben 10 hat einen Federraum 88, in dem die Druckfeder 86 angeordnet ist, die sich mit einem ersten Ende an einer Innenfläche 90 des Steuerkolbens 6 und mit ihrem zweiten Ende an einem Federteller 92 abstützt und diesen gegen eine Innenwandung 94 des Steuerkolbens 6 vorspannt. Der Federteller 92 ist über eine in einer Durchgangsbohrung 96 des Steuerkolbens 10 geführte Stange 98 als Verbindungselement mit der Stellhülse 66 des Gewindetriebs 64 verbunden, wobei der Steuerkolben 6 bei Überschreiten der Federvorspannung gegen die Kraft der Druckfeder 86 entlang des Stange 98 bewegbar ist.In order to avoid damage to the drive system when the pressure in the hydraulic system drops, the control piston 6 is supported on the screw drive 64 via a prestressed compression spring 86. The control piston 10 has a spring chamber 88, in which the compression spring 86 is arranged, which is supported with a first end on an inner surface 90 of the control piston 6 and with its second end to a spring plate 92 and biases it against an inner wall 94 of the control piston 6. The spring plate 92 is connected via a guided in a through hole 96 of the control piston 10 rod 98 as a connecting element with the adjusting sleeve 66 of the screw 64, wherein the control piston 6 when the spring bias is exceeded against the force of the compression spring 86 along the rod 98 is movable.

Im Folgenden wird die Funktion der elektrohydraulischen Antriebseinrichtung 1 anhand der Figur beispielhaft erläutert.The function of the electrohydraulic drive device 1 will be explained below by way of example with reference to the FIGURE.

In dem dargestellten Grundzustand der elektrohydraulischen Antriebseinrichtung 1 sind die Ringnuten 26, 30 des Stellkolbens 10 von der Außenumfangswandung 100 des Steuerkolbens 6 überdeckt, wobei sich die obere Steuerkante 16 des Stellkolbens 10 oberhalb und die untere Steuerkante 18 des Stellkolbens 10 unterhalb der Ringnut 28 des Steuerkolbens 6 befindet. Dadurch ist die Druckmittelverbindung von dem Druckraum 36 und damit vom Hochdruckspeicher 22 in den Arbeitsraum 20 und die Verbindung von dem Arbeitsraum 20 zu dem Niederdruckspeicher 24 unterbrochen. Der Hochdruckspeicher 22 ist über den Versorgungskanal 42 mit dem Druckraum 36 verbunden. Der Raum 102 oberhalb des Steuerkolbens 6 ist über den Entlastungskanal 48, die Ringnut 30 des Stellkolbens 10, die Durchgangsbohrung 50 und die Ringnut 52 des Zylindergehäuses 2 über den Rücklaufkanal 54 mit dem Niederdruck-speicher 24 verbunden. Im Grundzustand der elektrohydraulischen Antriebseinrichtung 1 ist die den Druckraum 36 begrenzende Wirkfläche 39 des Stellkolbens 10 derart mit Druck beauf-schlagt, dass im Wesentlichen ein Gewichtsausgleich der zu bewegenden Masse erfolgt. Insbesondere werden etwa 60 bis 80% der auf den Stellkolben 10 lastenden Gewichtskraft von der Druckkraft auf die Wirkfläche 39 des Druckraumes 36 und der Rest durch die Druckraft auf die Wirkfläche 41 des Arbeitsraumes 20 aufgenommen.In the illustrated basic state of the electro-hydraulic drive device 1, the annular grooves 26, 30 of the actuating piston 10 are covered by the outer peripheral wall 100 of the control piston 6, wherein the upper control edge 16 of the actuating piston 10 above and the lower control edge 18 of the actuating piston 10 below the annular groove 28 of the control piston 6 is located. As a result, the pressure medium connection is interrupted by the pressure chamber 36 and thus by the high pressure accumulator 22 in the working space 20 and the connection from the working space 20 to the low pressure accumulator 24. The high-pressure accumulator 22 is connected via the supply channel 42 to the pressure chamber 36. The space 102 above the control piston 6 is connected via the discharge channel 48, the annular groove 30 of the actuating piston 10, the through hole 50 and the annular groove 52 of the cylinder housing 2 via the return passage 54 to the low-pressure storage 24. In the initial state of the electrohydraulic drive device 1, the effective area 39 bounding the pressure chamber 36 of the actuating piston 10 is pressurized in such a way that essentially a weight compensation of the mass to be moved takes place. In particular, about 60 to 80% of the load on the adjusting piston 10 weight force of the pressure force on the active surface 39 of the pressure chamber 36 and the rest by the pressure force on the active surface 41 of the working space 20 is added.

Zum Anheben der Last wird der Elektromotor 8 betätigt, der über das Antriebsrad 82 und den Zahnriemen 80 die Gewindemutter 72 antreibt, die über ein Innengewinde 104 mit der drehfest aber axial verschiebbar in dem Aufnahmeraum 68 des Zylindergehäuses 2 aufgenommene Stellhülse 66 in Wirkverbindung steht. Die Gewindemutter 72 ist beidseitig über die Axiallager 76, 78 in dem Zylindergehäuse 2 gelagert, so dass der Gewindetrieb 64 die Drehbewegung des Elektromotors 8 in eine Axialbewegung der Stellhülse 66 relativ zu dem Zylindergehäuse 2 umwandelt. Da der Steuerkolben 6 über die vorgespannte Druckfeder 86 an dem Gewindetrieb 64 abgestützt ist, wird dieser in der einen Drehrichtung des Elektromotors 8 entsprechend der Axialbewegung der Stellhülse 66 nach oben verschoben, wobei die Druckmittelverbindung von dem Druckraum 36 des Stellkolbens 10 über die Steuerkante 12 des Steuerkolbens 6 zu der Ringnut 28 des Steuerkolbens 6 aufgesteuert und gleichzeitig über die Steuerkante 14 des Steuerkolbens 6 die Verbindung zum Niederdruckspeicher 24 zugesteuert wird. Dadurch wird eine Verbindung von der Hochdruckquelle 22 über den Versorgungskanal 42, den Druckraum 36 des Stellkolbens 10, den Verbindungskanal 44, die Ringnut 26 des Stellkolbens 10 über die Ringnut 28 des Steuerkolbens 6 und den Druckmittelkanal 46 zu dem Arbeitsraum 20 hin aufgesteuert, so dass Druckmittel von dem Hochdruckspeicher 22 in den Arbeitsraum 20 strömt und der Stellkolben 10 nach oben bewegt wird.To lift the load, the electric motor 8 is actuated, which drives the threaded nut 72 via the drive wheel 82 and the toothed belt 80, which is connected via an internal thread 104 with the rotatably but axially displaceably received in the receiving space 68 of the cylinder housing 2 actuating sleeve 66 in operative connection. The threaded nut 72 is mounted on both sides via the thrust bearings 76, 78 in the cylinder housing 2, so that the screw 64 converts the rotational movement of the electric motor 8 in an axial movement of the adjusting sleeve 66 relative to the cylinder housing 2. Since the control piston 6 is supported by the preloaded compression spring 86 on the screw 64, this is in the one direction of rotation of the electric motor 8 according to the Axial movement of the adjusting sleeve 66 is shifted upward, wherein the pressure medium connection is controlled by the pressure chamber 36 of the actuating piston 10 via the control edge 12 of the control piston 6 to the annular groove 28 of the control piston 6 and at the same time via the control edge 14 of the control piston 6 the connection to the low-pressure accumulator 24 is controlled. As a result, a connection from the high-pressure source 22 via the supply channel 42, the pressure chamber 36 of the actuating piston 10, the connecting channel 44, the annular groove 26 of the actuating piston 10 via the annular groove 28 of the control piston 6 and the pressure medium channel 46 to the working space 20 up controlled, so that Pressure fluid from the high pressure accumulator 22 flows into the working space 20 and the adjusting piston 10 is moved upward.

Der Stellkolben 10 bewegt sich so lange nach oben, bis die Druckmittelverbindung zu dem Arbeitsraum 20 über die Steuerkante 16 des Stellkolbens 10 unterbrochen wird. Dadurch bewegt sich der Stellkolben 10 um die gleiche Strecke wie der Steuerkolben 6 nach oben, wobei die Stellbewegung der Bewegung des Elektromotors 8 entspricht, so dass die Stellbewegung des Elektromotors als Istwert der Stellkolbenposition verwendbar ist. Um bei einem Druckabfall eine Beschädigung des Antriebes zu vermeiden, kann sich der Steuerkolben 6 gegen die Kraft der vorgespannten Druckfeder 86 gegenüber der Stellhülse 66 bewegen, so dass Stoßkräfte auf den Antrieb auf ein Minimum reduziert sind.The actuating piston 10 moves upward until the pressure medium connection to the working chamber 20 is interrupted via the control edge 16 of the actuating piston 10. As a result, the actuating piston 10 moves by the same distance as the control piston 6 upwards, wherein the adjusting movement of the movement of the electric motor 8 corresponds, so that the adjusting movement of the electric motor is used as the actual value of the actuating piston position. In order to avoid damage to the drive at a pressure drop, the control piston 6 can move against the force of the prestressed compression spring 86 relative to the adjusting sleeve 66, so that impact forces are reduced to the drive to a minimum.

Zum Absenken des Stellkolbens 10 wird der Elektromotor 8 in die entgegengesetzte Richtung angetrieben und der Steuerkolben 6 nach unten bewegt. Dadurch öffnet sich ein Durchflussquerschnitt zwischen den Steuerkanten 14 und 18. Durch die Last wird Druckflüssigkeit aus dem Arbeitsraum 20 in den Niederdruckspeicher 24 verdrängt. Der Stellkolben 10 folgt also dem Steuerkolben 6 nach unten, bis der Durchflussquerschnitt zwischen den Steuerkanten 14 und 18 wieder geschlossen ist.To lower the actuating piston 10, the electric motor 8 is driven in the opposite direction and the control piston 6 moves downward. This opens a flow cross-section between the control edges 14 and 18. By the load pressure fluid is displaced from the working space 20 in the low pressure accumulator 24. The actuating piston 10 thus follows the control piston 6 down until the flow cross-section between the control edges 14 and 18 is closed again.

Offenbart ist eine elektrohydraulische Antriebseinrichtung mit einem Zylindergehäuse 2 an dem ein Steuerkolben 6 geführt ist, der über einen Elektromotor 8 axial verschiebbar ist und mit einem Stellkolben 10 zusammenwirkt. Erfindungsgemäß ist der Steuerkolben 6 zumindest abschnittsweise innerhalb des Stellkolbens 10 geführt, wobei der Steuerkolben 6 mindestens zwei Steuerkanten 12, 14 aufweist, über die eine Druckmittelverbindung zwischen einem vom Stellkolben 10 abschnittsweise begrenzten Arbeitsraum 20 und einer Druckmittelquelle 22 oder einer Druckmittelsenke 24 auf- oder zusteuerbar ist.Disclosed is an electro-hydraulic drive device with a cylinder housing 2 on which a control piston 6 is guided, which is axially displaceable via an electric motor 8 and cooperates with a control piston 10. According to the invention, the control piston 6 is at least partially guided within the actuating piston 10, wherein the control piston 6 at least two control edges 12, 14, via a pressure medium connection between a part of the control piston 10 partially limited working space 20 and a pressure medium source 22 or a pressure medium sink 24 up or steered is.

Claims (15)

  1. Electrohydraulic drive device, in particular for a blow pin of a blow-moulding machine, with a cylinder housing (2), guided on which is a control piston (6), which can be axially displaced by means of an electric motor (8) and interacts with an adjusting piston (10), characterized in that the control piston (6) is guided at least in certain portions within the adjusting piston (10), the control piston (6) having at least two control edges (12, 14), by way of which a pressure medium connection between a working space (20), bounded in certain portions by the adjusting piston (10), and a pressure medium source (22) or a pressure medium sink (24) can be opened or closed in a controllable manner.
  2. Drive device according to Patent Claim 1, the electric motor (8) having a position sensing system.
  3. Drive device according to Patent Claim 1 or 2, the adjusting piston (10) bounding with the cylinder housing (2) a pressure space (36) that is connected to the pressure medium source (22) and is effective in the direction of extension.
  4. Drive device according to Patent Claim 3, the adjusting piston (10) having an annular groove (32), which is entered by an annular casing (34) of the cylinder housing (2) and bounds the pressure space (36), while an inner part (38) of the adjusting piston (10) that enters a receiving bore (4) of the cylinder housing (2) bounds with the control piston (6) the working space (20).
  5. Drive device according to Patent Claim 3 or 4, an effective area (39) of the adjusting piston (10) that is assigned to the pressure space (36) being exposed to pressure in such a way that there is substantially a counterbalancing of the weight of the mass to be moved.
  6. Drive device according to Patent Claim 5, the effective area (39) having a greater cross section than an effective area (41) of the adjusting piston (10) that is assigned to the working space (20) and is effective in the same direction.
  7. Drive device according to one of the preceding patent claims, the control edges (12, 14; 16, 18) of the control piston (6) and/or of the adjusting piston (10) being formed by annular grooves (26, 28, 30) or pockets.
  8. Drive device according to one of the preceding patent claims, the working space (20) being able to be connected to the pressure medium sink (24) via the control piston (6) and a return channel (54) in the cylinder housing (2).
  9. Drive device according to one of the preceding patent claims, the pressure medium source (22) having at least one high-pressure accumulator.
  10. Drive device according to Patent Claim 9, the high-pressure accumulator (22) being assigned at least one charge pump (60).
  11. Drive device according to Patent Claim 10, the pressure medium sink (24) having at least one low-pressure accumulator feeding the charge pump (60).
  12. Drive device according to one of the preceding patent claims, the axial displacement of the control piston (6) taking place by way of a leadscrew (64).
  13. Drive device according to Patent Claim 12, the control piston (6) being supported on the leadscrew (64) by way of at least one pretensioned spring (86).
  14. Drive device according to Patent Claim 13, the control piston (6) having a spring space (88), arranged in which is the at least one spring (86), which is supported with a first end on an inner surface (90) of the control piston (6) and with its second end on a spring plate (92) and pretensions the latter against an inner wall (94) of the control piston (6), the spring plate (92) being connected to an adjusting sleeve (66) of the leadscrew (64) by way of a connecting element (98) projecting out of the control piston (6).
  15. Drive device according to Patent Claim 14, the control piston (6) being able to move along the connecting element (98) against the force of the spring (86) when the spring pretensioning is exceeded.
EP20070123422 2007-02-19 2007-12-18 Electrohydraulic actuator device Not-in-force EP1959146B1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE200710008092 DE102007008092A1 (en) 2007-02-19 2007-02-19 Electrohydraulic drive device

Publications (3)

Publication Number Publication Date
EP1959146A2 EP1959146A2 (en) 2008-08-20
EP1959146A3 EP1959146A3 (en) 2011-03-09
EP1959146B1 true EP1959146B1 (en) 2012-07-11

Family

ID=39485171

Family Applications (1)

Application Number Title Priority Date Filing Date
EP20070123422 Not-in-force EP1959146B1 (en) 2007-02-19 2007-12-18 Electrohydraulic actuator device

Country Status (2)

Country Link
EP (1) EP1959146B1 (en)
DE (1) DE102007008092A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102011015672B4 (en) * 2011-03-31 2021-10-07 new HESTA blow moulding solutions GmbH & Co. KG Drive device for the blow mandrel of a blow molding machine

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH668463A5 (en) * 1984-05-14 1988-12-30 Sig Schweiz Industrieges Servo drive for fuel injection pump - has stepping motor driven plunger with hydraulic backing
DE8703507U1 (en) 1987-03-09 1987-04-30 Gildemeister Ag, 4800 Bielefeld, De
DE3836401A1 (en) * 1988-10-26 1990-05-03 Bosch Gmbh Robert Hydraulic linear drive
ATE166951T1 (en) * 1994-03-09 1998-06-15 Eckehart Schulze HYDRAULIC DRIVE UNIT
DE19537109C2 (en) 1995-10-05 2003-04-24 Hesta Graham Gmbh & Co Kg Method for controlling the feed and retraction movements of the blow mandrel of a blow molding machine

Also Published As

Publication number Publication date
EP1959146A2 (en) 2008-08-20
EP1959146A3 (en) 2011-03-09
DE102007008092A1 (en) 2008-08-21

Similar Documents

Publication Publication Date Title
DE19909712B4 (en) Control valve device for a hydraulic consumer
EP2960561A1 (en) Hydraulic valve
DE102011017795B4 (en) door closers
DE3720266C2 (en)
EP0937206B1 (en) Pneumatic or hydraulic control motor with a shutoff device
DE102005052755A1 (en) Hydraulically operated clamping unit and thus executed hydraulic control axis
EP1958754A1 (en) Actuator device, in particular for a mobile component on a plastic injection machine or blow moulding machine
EP1478559A1 (en) Thrust piece unit for rack-steering gears
EP1959146B1 (en) Electrohydraulic actuator device
EP0975856B1 (en) Lift valve and hydraulical control device therefor
DE2910530C2 (en) Electro-hydraulic follow-up amplifier
DE2156696A1 (en) CONTROL DEVICE WITH A MEASURING SPINDLE AND A DRIVE PART
DE4036589A1 (en) CYLINDER PISTON UNIT
DE3919175A1 (en) CONTROL DEVICE FOR AN ADJUSTABLE PUMP
EP1416165A2 (en) Pneumatic cylinder
EP0089568B1 (en) Fluid operated linear-to-rotary actuator
DE19757157C2 (en) Hydraulic linear drive
DE19524777B4 (en) Door closer with adjustable preload of a closer spring
DE19903511A1 (en) Setting motor with switching-off device, with at least one compression spring between free piston and working piston
EP1853826A2 (en) Hydraulic valve
DE2806929C2 (en) Fluid operated servomotor with follow-up control
EP0745042B1 (en) Power steering for motor vehicles
DE8307197U1 (en) Working cylinder for pneumatic or hydraulic pressure media
DE19524778B4 (en) Door closer with a displacer
DE2944471A1 (en) Pneumatic actuator generating rotary movement - has hydraulic damping chamber discharged via throttle on movement of rack

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL BA HR MK RS

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL BA HR MK RS

17P Request for examination filed

Effective date: 20110909

AKX Designation fees paid

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE SI SK TR

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE SI SK TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: AT

Ref legal event code: REF

Ref document number: 566293

Country of ref document: AT

Kind code of ref document: T

Effective date: 20120715

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

Free format text: LANGUAGE OF EP DOCUMENT: GERMAN

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 502007010191

Country of ref document: DE

Effective date: 20120906

REG Reference to a national code

Ref country code: NL

Ref legal event code: VDEP

Effective date: 20120711

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG4D

Effective date: 20120711

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20121111

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20120711

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20120711

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20120711

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20121012

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20121112

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20120711

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20120711

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20120711

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20120711

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20120711

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20121022

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20120711

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20120711

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20120711

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20120711

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20120711

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20120711

26N No opposition filed

Effective date: 20130412

BERE Be: lapsed

Owner name: ROBERT BOSCH G.M.B.H.

Effective date: 20121231

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20121011

Ref country code: MC

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20121231

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 502007010191

Country of ref document: DE

Effective date: 20130412

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20121218

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20130830

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20121231

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20121231

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20121218

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20121231

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20120711

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20130102

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20121218

REG Reference to a national code

Ref country code: AT

Ref legal event code: MM01

Ref document number: 566293

Country of ref document: AT

Kind code of ref document: T

Effective date: 20121218

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20120711

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20140221

Year of fee payment: 7

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20121218

Ref country code: AT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20121218

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: HU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20071218

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 502007010191

Country of ref document: DE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20150701