WO1998048174A1 - Driving mechanism for a hydraulic differential cylinder - Google Patents
Driving mechanism for a hydraulic differential cylinder Download PDFInfo
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- WO1998048174A1 WO1998048174A1 PCT/EP1998/000348 EP9800348W WO9848174A1 WO 1998048174 A1 WO1998048174 A1 WO 1998048174A1 EP 9800348 W EP9800348 W EP 9800348W WO 9848174 A1 WO9848174 A1 WO 9848174A1
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- drive
- pumps
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- piston
- differential cylinder
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- 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
- F15B7/00—Systems in which the movement produced is definitely related to the output of a volumetric pump; Telemotors
- F15B7/005—With rotary or crank input
- F15B7/006—Rotary pump input
Definitions
- the invention relates to a drive for a differential cylinder according to the preamble of claim 1.
- a drive for such a hydraulic cylinder is known from DE 40 08 792 A1.
- This drive shows two variable displacement pumps that are driven by a common drive.
- the first pump is used to convey working fluid from a tank into the enlarging cylinder space of the cylinder.
- a counter-pressure is built up in this cylinder chamber in the working medium displaced from the other cylinder chamber and the piston is clamped hydraulically.
- Both cylinder chambers are connected to each other via the second variable pump.
- a synchronous drive for a hydraulic cylinder is indeed realized with the known drive;
- the disadvantage of such a drive is that due to the use of variable pumps and the associated control device, the drive has a complicated structure and is expensive to manufacture.
- Publ.No. 08014208 A is a generic drive for a hydraulic cylinder with two constant pumps having a common drive.
- the known arrangement together with the valve control device serves to secure hanging loads acting on the working cylinder in such a way that a counterforce is generated in a neutral position, which helps to avoid an unwanted lowering of the load when the device is not actuated. Otherwise, the two constant pumps are used to control and thus extend and retract the piston rod of the hydraulic differential cylinder.
- a special synchronous drive is not provided here.
- a drive for a hydraulic differential cylinder is known with two jointly drivable constant pumps, the volumetric flow rate of one constant pump being significantly higher than that of the other in order to be able to provide a constant amount of fluid for actuating the differential cylinder , if this has to make large deflections in the short term, for example to control a mechanical control device in working machines or the like.
- a synchronous drive for the differential cylinder is also not provided here and this known solution also has a complicated structure and is therefore expensive to manufacture.
- the invention has for its object to provide a drive for a hydraulic differential cylinder with which a very precise synchronous drive for the differential cylinder can be achieved and which can be produced inexpensively.
- a relevant object is achieved with the features of claim 1.
- the constant pumps are arranged in parallel and are preferably connected on one side to the piston chamber of the cylinder via a common line.
- the two constant pumps are connected to the annulus of the cylinder via a common second line.
- a spring-loaded check valve is provided between the two constant pumps, which prevents hydraulic fluid from the circuit from entering the circuit to the second constant pump, which sucks additional hydraulic fluid from a tank via a further line to the volume difference between the piston space and
- the hydraulic fluid that is unnecessary due to the volume difference between the piston space and the annular space is delivered to the tank via the second constant pump.
- additional hydraulic fluid can be pumped from the tank into the circuit via a further line with a spring-loaded check valve.
- this line is provided on the piston chamber side and is connected to the tank.
- pressure lines are provided on the lines that connect the constant pumps to the cylinder, which protect the system from overloading. If the pressure is too high, the system can discharge hydraulic fluid via a line via the corresponding pressure valve. This line preferably conveys the hydraulic fluid delivered back into the tank.
- cross-connected check valves are provided to hold the position of the piston in the cylinder between the lines connecting the cylinder to the constant pumps.
- a hydraulically unlockable clamping device can alternatively be provided on the cylinder. This device ensures that the piston can only be extended or retracted when necessary.
- the arrangement of an additional memory in the system which is connected via directional valves to the lines connecting the cylinder to the constant pumps, is particularly advantageous. In the event of a power failure, movement of the piston, albeit limited, is possible. This storage can either be fed equally by both constant pumps or only by a certain constant pump.
- the memory is preferably arranged in connection with the pressure valves. These valves take over the functions of feeding and draining liquid in an emergency, as well as overload protection.
- the regulation of the motor driving the constant pumps via a controller which is regulated as a function of the measured actual values in relation to a predetermined setpoint via an actuating signal, enables an optimal efficiency of the system, since control-related throttle valves are omitted, which saves costs.
- FIG. 2 shows a representation of a first variant with pressure valves for protection against overload and non-return valves for holding the position of the piston in the differential cylinder
- Fig. 3 is an illustration of an alternative embodiment of
- FIG. 2 with a hydraulically unlockable clamping device for holding the differential cylinder
- FIG. 4 shows a further development of the drive for a differential cylinder from FIG. 2 with an additional memory and directional valves for emergency movements in the event of a power failure
- FIG. 5 shows a variant of FIG. 4,
- Fig. 6 is an illustration of a drive for a differential cylinder with a closed system
- Fig. 7 is an illustration of a drive for a differential cylinder with a controlled drive.
- 1 shows a differential cylinder 1 with a piston 2.
- the differential cylinder 1 has a piston chamber 3 and an annular chamber 4.
- the differential cylinder 1 has the effective piston surface A 3 in the piston space 3 and the effective piston ring surface A 4 in the annular space.
- the difference between the two surfaces (A 3 - A 4 ) corresponds to the cross-sectional area A St of the piston rod.
- two constant pumps 5 and 6 are provided, which are driven by means of a motor 7.
- the two constant pumps 5 and 6 are connected in parallel and connected to the piston chamber 3 and the annular chamber 4 via lines 8 and 9.
- a spring-loaded check valve 1 3 is provided on the side of the line 8 which is connected to the piston chamber 3, between the constant pump 6 and the line section 11.
- the system is connected via lines 1 1 and 1 2 to a tank (not shown) in which hydraulic fluid is stored.
- a spring-loaded check valve 10 is provided on the side of the line 9, which is connected to the annular space 4, between the constant displacement pumps 5 and 6.
- a spring-loaded check valve 1 3 is provided on the side of the line 8 which is connected to the piston chamber 3, between the constant pump 6 and the line section 11.
- the two constant pumps 5 and 6 deliver hydraulic fluid via the line 8 into the piston chamber 3. This increases the volume in the piston chamber 3, the piston 2 extends. Simultaneously with the increase in volume of the piston space 3, the volume of the annular space 4 decreases. The hydraulic fluid displaced from the annular space 4 is conveyed into the piston space 3 by the constant pump 5.
- the constant pumps 5 and 6 move the hydraulic fluid into promote the opposite direction.
- the constant pump 5 conveys liquid into the annular space 4. Due to the piston movement, the hydraulic fluid is displaced from the piston space 3 and taken up by the constant pumps 5 and 6, the constant pump 6 delivering the hydraulic fluid back to the tank via line 12.
- a pressure valve 21 is connected to line 8 and a pressure valve 22 is connected to line 9 in order to protect the drive against overload.
- the hydraulic fluid discharged via the pressure valves 21 and 22 in the event of an overload is supplied to the tank via a line 23.
- a first embodiment is shown in Fig. 2, in which it is ensured that the piston 2 in the differential cylinder 1 holds its position when necessary.
- two unlockable check valves 25 and 26 are provided, which can be unlocked crosswise by means of lines 27 and 28 and thus opened.
- FIG. 1 An alternative embodiment, which also ensures that the position of the piston is held in differential cylinder 1, is shown in FIG.
- a hydraulically unlockable clamping device 31 is provided on the differential cylinder 1.
- FIG. 4 essentially corresponds to FIG. 2, but in addition a memory 41 is provided which enables the piston 2 in the differential cylinder 1 to make emergency movements in the event of a power failure.
- the memory 41 is connected to the constant pumps 5 and 6 via check valves and is charged by the constant pumps 5, 6.
- the valves 42 and 43 take over both the overload protection of the drive and, in the event of emergency operation, the feeding of hydraulic fluid into the annular space 4 or the piston space 3 and the rear line of displaced hydraulic fluid from the other room into the tank.
- Figure 5 shows a variant of Figure 4, according to which the memory 41 is fed by a certain constant pump, according to the illustration of Figure 5 by the constant pump 5.
- Figure 6 corresponds essentially to Figure 4, but this drive is a closed system in which the hydraulic fluid has no contact with the atmosphere.
- a reservoir 61 is provided which stores the hydraulic fluid.
- FIG. 7 shows a further development of FIG. 6 according to which the drive is regulated by means of a controller 71 in accordance with a predetermined setpoint, symbolically indicated by the arrow 72.
- the setpoint is compared with an actual value measured on differential cylinder 1, symbolically indicated by arrow 73.
- the controller 71 emits an actuating signal according to which the operation of the motor 7 is changed.
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Abstract
Description
Antrieb für einen hydraulischen Differentialzylinder Drive for a hydraulic differential cylinder
Die Erfindung betrifft einen Antrieb für einen Differentialzylinder gemäß dem Oberbegriff des Anspruchs 1 .The invention relates to a drive for a differential cylinder according to the preamble of claim 1.
Ein Antrieb für einen dahingehenden hydraulischen Zylinder ist aus der DE 40 08 792 A1 bekannt. Dieser Antrieb zeigt zwei Verstellpumpen, die von einem gemeinsamen Antrieb angetrieben werden. Die erste Pumpe dient zum Fördern von Arbeitsmittel aus einem Tank in den sich vergrößernden Zylinderraum des Zylinders. Dabei wird in dem aus dem anderen Zylinderraum verdrängten Arbeitsmittel ein Gegendruck in diesem Zylinderraum aufgebaut und der Kolben hydraulisch eingespannt. Beide Zylinderräume sind über die zweite Verstellpumpe miteinander verbunden.A drive for such a hydraulic cylinder is known from DE 40 08 792 A1. This drive shows two variable displacement pumps that are driven by a common drive. The first pump is used to convey working fluid from a tank into the enlarging cylinder space of the cylinder. A counter-pressure is built up in this cylinder chamber in the working medium displaced from the other cylinder chamber and the piston is clamped hydraulically. Both cylinder chambers are connected to each other via the second variable pump.
Zwar ist mit dem bekannten Antrieb ein Gleichgangantrieb für einen hydraulischen Zylinder realisiert; Nachteil eines derartigen Antriebes ist jedoch, daß durch die Verwendung von Verstellpumpen sowie der zugehörigen Regeleinrichtung der Antrieb kompliziert aufbaut und teuer in der Herstellung ist.A synchronous drive for a hydraulic cylinder is indeed realized with the known drive; However, the disadvantage of such a drive is that due to the use of variable pumps and the associated control device, the drive has a complicated structure and is expensive to manufacture.
Durch den Patent Abstracts of Japan, Publ.No. 08014208 A ist ein gattungsgemäßer Antrieb für einen hydraulischen Zylinder bekannt mit zwei einen gemeinsamen Antrieb aufweisenden Konstantpumpen. Die bekannte Anordnung nebst Ventilsteuereinrichtung dient dazu, am Arbeitszylinder angreifende, hängende Lasten derart abzusichern, daß in einer neutralen Stellung eine Gegenhaltekraft erzeugt ist, die ein ungewolltes Absenken der Last bei nicht- betätigter Einrichtung vermeiden hilft. Ansonsten dienen die beiden Konstantpumpen dem Ansteuern und mithin dem Ein- und Ausfahren der Kolbenstange des hydraulischen Differentialzylinders. Ein spezieller Gleichgangantrieb ist hierbei nicht vorgesehen.Through the Patent Abstracts of Japan, Publ.No. 08014208 A is a generic drive for a hydraulic cylinder with two constant pumps having a common drive. The known arrangement together with the valve control device serves to secure hanging loads acting on the working cylinder in such a way that a counterforce is generated in a neutral position, which helps to avoid an unwanted lowering of the load when the device is not actuated. Otherwise, the two constant pumps are used to control and thus extend and retract the piston rod of the hydraulic differential cylinder. A special synchronous drive is not provided here.
Durch die US 3 1 54 921 ist ein Antrieb für einen hydraulischen Differentialzylinder bekannt mit zwei gemeinsam antreibbaren Konstantpumpen, wobei die volumetrische Förderleistung der einen Konstantpumpe wesentlich höher ist als die der anderen, um eine konstante Fluidmenge für das Ansteuern des Differentialzylinders zur Verfügung stellen zu können, wenn dieser beispielsweise zum Ansteuern einer mechanischen Steuereinrichtung bei Arbeitsmaschinen oder dergleichen kurzfristig große Auslenkungen vorzunehmen hat. Ein Gleichgangantrieb für den Differentialzylinder ist hierbei gleichfalls nicht vorgesehen und auch diese bekannte Lösung baut kompliziert auf und ist mithin teuer in der Herstellung,From US 3 1 54 921 a drive for a hydraulic differential cylinder is known with two jointly drivable constant pumps, the volumetric flow rate of one constant pump being significantly higher than that of the other in order to be able to provide a constant amount of fluid for actuating the differential cylinder , if this has to make large deflections in the short term, for example to control a mechanical control device in working machines or the like. A synchronous drive for the differential cylinder is also not provided here and this known solution also has a complicated structure and is therefore expensive to manufacture.
Ausgehend von diesem Stand der Technik liegt der Erfindung die Aufgabe zugrunde, einen Antrieb für einen hydraulischen Differentialzylinder zu schaffen, mit dem ein sehr genauer Gleichgangäntrieb für den Differentialzylinder erreichbar ist und der sich kostengünstig herstellen läßt. Eine dahingehende Aufgabe wird mit den Merkmalen des Anspruches 1 gelöst. Dadurch, daß gemäß dem kennzeichnenden Teil die Hubvolumina der Konstantpumpen pro Umdrehung (V6 : V5) das gleiche Verhältnis aufweisen wie das Flächenverhältnis zwischen Kolbenstangenquerschnitt und Kolbenringfläche des Differentialzylinders, ist ein sehr genau arbeitender Gleichgangantrieb für den Differentialzylinder geschaffen, der darüber hinaus kostengünstig sich realisieren läßt, da keine aufwendige Regel- oder Ventilsteuereinrichtung notwendig ist, sondern vielmehr die Ansteuerung des Differentialzylinders ausschließlich über die Konstantpumpen erfolgt.Based on this prior art, the invention has for its object to provide a drive for a hydraulic differential cylinder with which a very precise synchronous drive for the differential cylinder can be achieved and which can be produced inexpensively. A relevant object is achieved with the features of claim 1. The fact that, according to the characteristic part, the stroke volumes of the constant pumps per revolution (V 6 : V 5 ) have the same ratio as the area ratio between the piston rod cross-section and the piston ring area of the differential cylinder, a very precisely working synchronous drive for the differential cylinder is created, which is also inexpensive can be realized, since no complex control or valve control device is necessary, but rather the differential cylinder is actuated exclusively via the constant pumps.
Die Konstantpumpen sind parallel angeordnet und vorzugsweise auf ihrer einen Seite über eine gemeinsame Leitung mit dem Kolbenraum des Zylinders verbunden. Mit ihrer anderen Seite sind die beiden Konstantpumpen über eine gemeinsame zweite Leitung mit dem Ringraum des Zylinders verbunden. Auf der Seite des Ringraumes ist zwischen den beiden Konstantpumpen ein federbelastetes Rückschlagventil vorgesehen, das verhindert, daß beim Einfahren des Kolbens Hydraulikflüssigkeit aus dem Kreislauf zur zweiten Konstantpumpe gelangt, die aus einem Tank über eine weitere Leitung zusätzliche Hydraulikflüssigkeit ansaugt, um die Volumendifferenz zwischen Kolbenraum und Ringraum auszugleichen, im Falle des Einfahrens des Hydraulikzylinders wird über die zweite Konstantpumpe die aufgrund der Volumendifferenz zwischen Kolbenraum und Ringraum überflüssige Hydraulikflüssigkeit an den Tank abgegeben. Im Bedarfsfall kann jedoch über eine weitere Leitung mit einem federbelasteten Rückschlagventil zusätzliche Hydraulikflüssigkeit aus dem Tank in den Kreislauf gefördert werden. Hierfür ist auf der Kolbenraumseite diese Leitung vorgesehen, die mit dem Tank verbunden ist.The constant pumps are arranged in parallel and are preferably connected on one side to the piston chamber of the cylinder via a common line. On the other side, the two constant pumps are connected to the annulus of the cylinder via a common second line. On the side of the annulus, a spring-loaded check valve is provided between the two constant pumps, which prevents hydraulic fluid from the circuit from entering the circuit to the second constant pump, which sucks additional hydraulic fluid from a tank via a further line to the volume difference between the piston space and To compensate for the annular space, in the event that the hydraulic cylinder is retracted, the hydraulic fluid that is unnecessary due to the volume difference between the piston space and the annular space is delivered to the tank via the second constant pump. If necessary, however, additional hydraulic fluid can be pumped from the tank into the circuit via a further line with a spring-loaded check valve. For this purpose, this line is provided on the piston chamber side and is connected to the tank.
Insbesondere bei Stellzylindern mit einem Verhältnis zwischen Kolbenstangenfläche und Kolbenringfläche von 1 :1 ergibt sich die preiswerte Lösung der Verwendung einer' Doppelpumpe mit gleichem Hubvolumen. Gemäß einer vorteilhaften Ausgestaltungsform sind an den Leitungen, die die Konstantpumpen mit dem Zylinder verbunden, Druckventile vorgesehen, die das System vor einer Überlastung schützen. Im Falle eines zu hohen Drucks kann über das entsprechende Druckventil Hydraulikflüssigkeit über eine Leitung vom System abgegeben werden. Vorzugsweise fördert diese Leitung die abgegebene Hydraulikflüssigkeit zurück in den Tank.In particular, in actuating cylinders having a ratio between the piston rod surface and the piston ring area of 1: 1, the low-cost solution using the results of a 'double pump with the same displacement. According to an advantageous embodiment, pressure lines are provided on the lines that connect the constant pumps to the cylinder, which protect the system from overloading. If the pressure is too high, the system can discharge hydraulic fluid via a line via the corresponding pressure valve. This line preferably conveys the hydraulic fluid delivered back into the tank.
Gemäß einer bevorzugten Ausführungsform sind zum Halten der Position des Kolbens im Zylinder zwischen den Leitungen, die den Zylinder mit den Konstantpumpen verbinden, über Kreuz geschaltete Rückschlagventile vorgesehen.According to a preferred embodiment, cross-connected check valves are provided to hold the position of the piston in the cylinder between the lines connecting the cylinder to the constant pumps.
Zum Halten der Position des Kolbens kann alternativ am Zylinder eine hydraulisch entsperrbare Klemmvorrichtung vorgesehen werden. Diese Vorrichtung stellt sicher, daß der Kolben nur im Bedarsfall aus- oder eingefahren werden kann.To hold the position of the piston, a hydraulically unlockable clamping device can alternatively be provided on the cylinder. This device ensures that the piston can only be extended or retracted when necessary.
Besonders vorteilhaft ist die Anordnung eines zusätzlichen Speichers im System, der über Wegeventile mit den Leitungen, die den Zylinder mit den Konstantpumpen verbinden, verbunden ist. Im Falle eines Stromausfalles ist eine, wenn auch beschränkte Bewegung des Kolbens möglich. Dieser Speicher kann entweder gleichermaßen von beiden Konstantpumpen gespeist werden, oder aber nur durch eine bestimmte Konstantpumpe. Vorzugsweise ist der Speicher im Anschluß an die Druckventile angeordnet. Diese Ventile übernehmen die Funktionen der Einspeisung und Ableitung von Flüssigkeit im Notfall, wie auch den Überlastungsschutz.The arrangement of an additional memory in the system, which is connected via directional valves to the lines connecting the cylinder to the constant pumps, is particularly advantageous. In the event of a power failure, movement of the piston, albeit limited, is possible. This storage can either be fed equally by both constant pumps or only by a certain constant pump. The memory is preferably arranged in connection with the pressure valves. These valves take over the functions of feeding and draining liquid in an emergency, as well as overload protection.
Die Verwendung eines geschlossenen Systems macht den Stellantrieb unabhängig von der Einbaulage und damit universell einsetzbar. Außerdem erhöht sie die Lebensdauer der Hydrauljkflüssigkeit, da diese keinen Kontakt mit der Atmosphäre hat. So wird der natürliche Alterungsvorgang verlangsamt. Ferner erfolgt nur bedingt ein Entgasen flüchtiger Zusätze der Hydraulikflüssigkeit.The use of a closed system makes the actuator independent of the installation position and therefore universally applicable. It also increases the service life of the hydraulic fluid, since it does not come into contact with the Atmosphere. This slows down the natural aging process. Furthermore, degassing of volatile additives in the hydraulic fluid takes place only to a limited extent.
Die Regelung des die Kontantpumpen antreibenden Motors über einen Regler, der in Abhängigkeit von den gemessenen Istwerten in bezug auf einen vorgegebenen Sollwert über ein Stellsignal geregelt wird, ermöglicht einen optimalen Wirkungsgrad des Systems, da steuerungsbedingte Drosselventile entfallen, wodurch Kosten eingespart werden.The regulation of the motor driving the constant pumps via a controller, which is regulated as a function of the measured actual values in relation to a predetermined setpoint via an actuating signal, enables an optimal efficiency of the system, since control-related throttle valves are omitted, which saves costs.
Im folgenden wird die Erfindung anhand mehrerer Ausführungsbeispiele unter Bezugnahme auf die beiliegenden schematischen Zeichnungen näher erläutert.The invention is explained in more detail below on the basis of a number of exemplary embodiments and with reference to the accompanying schematic drawings.
Es zeigen:Show it:
Fig. 1 eine Darstellung des Grundprinzips eines Antriebs für einen Differentialzylinder,1 is an illustration of the basic principle of a drive for a differential cylinder,
Fig. 2 eine Darstellung einer ersten Variante mit Druckventilen zum Schutz vor Überlastung und Rückschlagventilen zum Halten der Position des Kolbens im Differentialzylinder,2 shows a representation of a first variant with pressure valves for protection against overload and non-return valves for holding the position of the piston in the differential cylinder,
Fig. 3 eine Darstellung einer alternativen Ausführungsform vonFig. 3 is an illustration of an alternative embodiment of
Figur 2 mit einer hydraulisch entsperrbaren Klemmvorrichtung zum Halten des Differentialzylinders,FIG. 2 with a hydraulically unlockable clamping device for holding the differential cylinder,
Fig. 4 eine Weiterentwicklung des Antriebs für einen Differentialzylinder von Fig. 2 mit einem zusätzlichen Speicher und Wegeventilen für Notbewegungen bei Stromausfall,4 shows a further development of the drive for a differential cylinder from FIG. 2 with an additional memory and directional valves for emergency movements in the event of a power failure,
Fig. 5 eine Variante von Fig. 4,5 shows a variant of FIG. 4,
Fig. 6 eine Darstellung eines Antriebs für einen Differentialzylinder mit einem geschlossenen System undFig. 6 is an illustration of a drive for a differential cylinder with a closed system and
Fig. 7 eine Darstellung eines Antriebs für einen Differentialzylinder mit einem geregelten Antrieb. Fig. 1 zeigt einen Differentialzylinder 1 mit einem Kolben 2. Der Differentialzylinder 1 weist einen Kolbenraum 3 und einen Ringraum 4 auf. Der Differentialzylinder 1 weist im Kolbenraum 3 die wirksame Kolbenfläche A3 und im Ringraum die wirksame Kolbenringfläche A4 auf. Die Differenz der beiden Flächen (A3 - A4) entspricht der Querschnittsfläche ASt der Kolbenstange. Als Antrieb für den Differentialzylinder 1 sind zwei Konstantpumpen 5 und 6 vorgesehen, die mit Hilfe eines Motors 7 angetrieben werden. Die beiden Konstantpumpen 5 und 6 sind parallel geschaltet und über Leitungen 8 und 9 mit dem Kolbenraum 3 bzw. dem Ringraum 4 verbunden. In gleicher Weise ist auf der Seite der Leitung 8, die mit dem Kolbenraum 3 verbunden ist, zwischen der Konstantpumpe 6 und dem Leitungsabschnitt 1 1 ein federbelastetes Rückschlagventil 1 3 vorgesehen. Das System ist über Leitungen 1 1 und 1 2 mit einem Tank (nicht dargestellt) verbunden, in dem Hydraulikflüssigkeit gespeichert ist. Zur Ermöglichung des Nachsaugens von Hydraulikflüssigkeit ist auf der Seite der Leitung 9, die mit dem Ringraum 4 verbunden ist, zwischen den Kontantpumpen 5 und 6 ein federbelastetes Rückschlagventil 10 vorgesehen. In gleicher Weise ist auf der Seite der Leitung 8, die mit dem Kolbenraum 3 verbunden ist, zwischen der Konstantpumpe 6 und dem Leitungsabschnitt 1 1 ein federbelastetes Rückschlagventil 1 3 vorgesehen.Fig. 7 is an illustration of a drive for a differential cylinder with a controlled drive. 1 shows a differential cylinder 1 with a piston 2. The differential cylinder 1 has a piston chamber 3 and an annular chamber 4. The differential cylinder 1 has the effective piston surface A 3 in the piston space 3 and the effective piston ring surface A 4 in the annular space. The difference between the two surfaces (A 3 - A 4 ) corresponds to the cross-sectional area A St of the piston rod. As the drive for the differential cylinder 1, two constant pumps 5 and 6 are provided, which are driven by means of a motor 7. The two constant pumps 5 and 6 are connected in parallel and connected to the piston chamber 3 and the annular chamber 4 via lines 8 and 9. In the same way, a spring-loaded check valve 1 3 is provided on the side of the line 8 which is connected to the piston chamber 3, between the constant pump 6 and the line section 11. The system is connected via lines 1 1 and 1 2 to a tank (not shown) in which hydraulic fluid is stored. To enable hydraulic fluid to be sucked in, a spring-loaded check valve 10 is provided on the side of the line 9, which is connected to the annular space 4, between the constant displacement pumps 5 and 6. In the same way, a spring-loaded check valve 1 3 is provided on the side of the line 8 which is connected to the piston chamber 3, between the constant pump 6 and the line section 11.
Um den Kolben 2 auszufahren, was in der Fig. 1 einer Bewegung nach oben entspricht, fördern die beiden Konstantpumpen 5 und 6 Hydraulikflüssigkeit über die Leitung 8 in den Kolbenraum 3. Dadurch erhöht sich im Kolbenraum 3 dessen Volumen, der Kolben 2 fährt aus. Gleichzeitig mit der Volumenvergrößerung des Kolbenraums 3 verringert sich das Volumen des Ringraums 4. Die aus dem Ringraum 4 verdrängte Hydraulikflüssigkeit wird durch die Konstantpumpe 5 in den Kolbenraum 3 gefördert.In order to extend the piston 2, which corresponds to an upward movement in FIG. 1, the two constant pumps 5 and 6 deliver hydraulic fluid via the line 8 into the piston chamber 3. This increases the volume in the piston chamber 3, the piston 2 extends. Simultaneously with the increase in volume of the piston space 3, the volume of the annular space 4 decreases. The hydraulic fluid displaced from the annular space 4 is conveyed into the piston space 3 by the constant pump 5.
Soll der Kolben 2 eingezogen werden, wird die Drehrichtung des Motors 7 umgedreht, wodurch die Konstantpumpen 5 und 6 die Hydraulikflüssigkeit in entgegengesetzter Richtung fördern. Die Konstantpumpe 5 fördert Flüssigkeit in den Ringraum 4. Durch die Kolbenbewegung wird die Hydraulikflüssigkeit aus dem Kolbenraum 3 verdrängt und von den Konstantpumpen 5 und 6 aufgenommen, wobei die Konstantpumpe 6 die Hydraulikflüssigkeit über Leitung 12 zurück zum Tank gibt.If the piston 2 is to be retracted, the direction of rotation of the motor 7 is reversed, as a result of which the constant pumps 5 and 6 move the hydraulic fluid into promote the opposite direction. The constant pump 5 conveys liquid into the annular space 4. Due to the piston movement, the hydraulic fluid is displaced from the piston space 3 and taken up by the constant pumps 5 and 6, the constant pump 6 delivering the hydraulic fluid back to the tank via line 12.
Gemäß einer ersten Variante, die in Figur 2 dargestellt ist, ist ein Druckventil 21 mit der Leitung 8 und ein Druckventil 22 mit der Leitung 9 verbunden, um den Antrieb vor Überlastung zu schützen. Die über die Druckventile 21 und 22 im Überlastungsfall abgegebene Hydraulikflüssigkeit wird über eine Leitung 23 dem Tank zugeführt.According to a first variant, which is shown in FIG. 2, a pressure valve 21 is connected to line 8 and a pressure valve 22 is connected to line 9 in order to protect the drive against overload. The hydraulic fluid discharged via the pressure valves 21 and 22 in the event of an overload is supplied to the tank via a line 23.
Zusätzlich ist in Fig. 2 eine erste Ausführungsform dargestellt, bei der sichergestellt wird, daß der Kolben 2 im Differentialzylinder 1 bei Bedarf seine Position hält. Gemäß dieser Ausführungsform sind zwei entsperrbare Rückschlagventile 25 und 26 vorgesehen, die über Kreuz mittels Leitungen 27 und 28 entsperrt und damit geöffnet werden können.In addition, a first embodiment is shown in Fig. 2, in which it is ensured that the piston 2 in the differential cylinder 1 holds its position when necessary. According to this embodiment, two unlockable check valves 25 and 26 are provided, which can be unlocked crosswise by means of lines 27 and 28 and thus opened.
Eine alternative Ausführungsform, die ebenfalls sicherstellt, daß die Position des Kolbens in Differentialzylinder 1 gehalten wird, ist in Fig. 3 dargestellt. Bei dieser Ausführungsform ist am Differentialzylinder 1 eine hydraulisch entsperrbare Klemmvorrichtung 31 vorgesehen.An alternative embodiment, which also ensures that the position of the piston is held in differential cylinder 1, is shown in FIG. In this embodiment, a hydraulically unlockable clamping device 31 is provided on the differential cylinder 1.
Figur 4 entspricht im wesentlichen der Figur 2, zusätzlich ist jedoch ein Speicher 41 vorgesehen, der bei Stromausfall Notbewegungen des Kolbens 2 im Differentialzylinder 1 ermöglicht. Der Speicher 41 ist über Rückschlagventile mit den Konstantpumpen 5 und 6 verbunden und wird darüber von den Konstantpumpen 5, 6 aufgeladen. Die Ventile 42 und 43 übernehmen sowohl den Überlastungsschutz des Antriebes, sowie bei Notbetrieb die Einspeisung von Hydraulikflüssigkeϊt in den Ringraum 4 oder den Kolbenraum 3 und die Rück- leitung verdrängter Hydraulikflüssigkeit aus dem jeweils anderen Raum in den Tank.FIG. 4 essentially corresponds to FIG. 2, but in addition a memory 41 is provided which enables the piston 2 in the differential cylinder 1 to make emergency movements in the event of a power failure. The memory 41 is connected to the constant pumps 5 and 6 via check valves and is charged by the constant pumps 5, 6. The valves 42 and 43 take over both the overload protection of the drive and, in the event of emergency operation, the feeding of hydraulic fluid into the annular space 4 or the piston space 3 and the rear line of displaced hydraulic fluid from the other room into the tank.
Figur 5 zeigt eine Variante von Figur 4, gemäß der der Speicher 41 durch eine bestimmte Konstantpumpe, gemäß der Darstellung von Figur 5 durch die Konstantpumpe 5 gespeist wird.Figure 5 shows a variant of Figure 4, according to which the memory 41 is fed by a certain constant pump, according to the illustration of Figure 5 by the constant pump 5.
Die Figur 6 entspricht im wesentlichen der Figur 4, jedoch handelt es sich bei diesem Antrieb um ein geschlossenes System, in dem die Hydraulikflüssigkeit keinen Kontakt mit der Atmosphäre hat. Anstelle des nicht dargestellten offenen Tanks gemäß der vorherigen Ausführungsbeispiele ist ein Speicher 61 vorgesehen, der die Hydraulikflüssigkeit speichert.Figure 6 corresponds essentially to Figure 4, but this drive is a closed system in which the hydraulic fluid has no contact with the atmosphere. Instead of the open tank (not shown) according to the previous exemplary embodiments, a reservoir 61 is provided which stores the hydraulic fluid.
Figur 7 zeigt eine Weiterentwicklung von Figur 6 gemäß der der Antrieb mittels eines Reglers 71 gemäß einem vorgegebenen Sollwert, symbolisch durch den Pfeil 72 angedeutet, geregelt wird. Dabei wird der Sollwert mit einem am Differentialzylinder 1 gemessenen Istwert, symbolisch durch den Pfeil 73 angedeutet, verglichen. Je nach Differenz des Soll- und Istwertes gibt der Regler 71 ein Stellsignal ab, gemäß dem der Betrieb des Motors 7 geändert wird. FIG. 7 shows a further development of FIG. 6 according to which the drive is regulated by means of a controller 71 in accordance with a predetermined setpoint, symbolically indicated by the arrow 72. The setpoint is compared with an actual value measured on differential cylinder 1, symbolically indicated by arrow 73. Depending on the difference between the setpoint and actual value, the controller 71 emits an actuating signal according to which the operation of the motor 7 is changed.
Claims
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19716081.6 | 1997-04-17 | ||
| DE1997116081 DE19716081C1 (en) | 1997-04-17 | 1997-04-17 | Hydraulic differential cylinder drive |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO1998048174A1 true WO1998048174A1 (en) | 1998-10-29 |
Family
ID=7826809
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/EP1998/000348 Ceased WO1998048174A1 (en) | 1997-04-17 | 1998-01-23 | Driving mechanism for a hydraulic differential cylinder |
Country Status (2)
| Country | Link |
|---|---|
| DE (1) | DE19716081C1 (en) |
| WO (1) | WO1998048174A1 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19857378A1 (en) * | 1998-12-12 | 2000-06-21 | Lfk Gmbh | Hydraulic manipulator |
| DE10303360A1 (en) * | 2003-01-29 | 2004-08-19 | O & K Orenstein & Koppel Gmbh | Hydraulic system for displacement-controlled linear drives |
| GB0329243D0 (en) * | 2003-12-17 | 2004-01-21 | Thales Plc | Apparatus and methods for actuation |
| US7325398B2 (en) * | 2004-03-05 | 2008-02-05 | Deere & Company | Closed circuit energy recovery system for a work implement |
| DE102006045211A1 (en) * | 2006-09-25 | 2008-04-03 | Robert Bosch Gmbh | Hydrostatic transmission |
| DE102013212937A1 (en) * | 2013-07-03 | 2014-07-10 | Voith Patent Gmbh | Device for opening and closing guide vane of hydraulic machine e.g. water turbine, has two fixed displacement pumps driven by rotation speed-variable drive and operated on hydraulic cylinder over hydraulic system |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3154921A (en) | 1962-01-19 | 1964-11-03 | Caterpillar Tractor Co | Fluid pressure system and control |
| DE2048782A1 (en) * | 1969-10-06 | 1971-04-22 | Elektrohydraulische Anlagen An | Hydraulic system for a machine with several hydraulically driven movement devices |
| GB2042077A (en) * | 1979-01-31 | 1980-09-17 | Johnson Progress Ltd | Filter presses |
| JPS58121306A (en) * | 1982-01-11 | 1983-07-19 | Kobe Steel Ltd | Hydraulic circuit for maintaining expansion and contraction of hydraulic cylinder |
| US4630441A (en) * | 1984-09-04 | 1986-12-23 | The Boeing Company | Electrohydraulic actuator for aircraft control surfaces |
| EP0314660A1 (en) * | 1987-10-28 | 1989-05-03 | BT Industries Aktiebolag | A hydraulic lifting arrangement |
| DE4008792A1 (en) | 1990-03-19 | 1991-09-26 | Rexroth Mannesmann Gmbh | DRIVE FOR A HYDRAULIC CYLINDER, IN PARTICULAR DIFFERENTIAL CYLINDER |
| JPH0814208A (en) | 1994-06-29 | 1996-01-16 | Sumitomo Constr Mach Co Ltd | Natural shrinkage preventing device for boom extension derricking cylinder |
-
1997
- 1997-04-17 DE DE1997116081 patent/DE19716081C1/en not_active Expired - Fee Related
-
1998
- 1998-01-23 WO PCT/EP1998/000348 patent/WO1998048174A1/en not_active Ceased
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3154921A (en) | 1962-01-19 | 1964-11-03 | Caterpillar Tractor Co | Fluid pressure system and control |
| DE2048782A1 (en) * | 1969-10-06 | 1971-04-22 | Elektrohydraulische Anlagen An | Hydraulic system for a machine with several hydraulically driven movement devices |
| GB2042077A (en) * | 1979-01-31 | 1980-09-17 | Johnson Progress Ltd | Filter presses |
| JPS58121306A (en) * | 1982-01-11 | 1983-07-19 | Kobe Steel Ltd | Hydraulic circuit for maintaining expansion and contraction of hydraulic cylinder |
| US4630441A (en) * | 1984-09-04 | 1986-12-23 | The Boeing Company | Electrohydraulic actuator for aircraft control surfaces |
| EP0314660A1 (en) * | 1987-10-28 | 1989-05-03 | BT Industries Aktiebolag | A hydraulic lifting arrangement |
| DE4008792A1 (en) | 1990-03-19 | 1991-09-26 | Rexroth Mannesmann Gmbh | DRIVE FOR A HYDRAULIC CYLINDER, IN PARTICULAR DIFFERENTIAL CYLINDER |
| JPH0814208A (en) | 1994-06-29 | 1996-01-16 | Sumitomo Constr Mach Co Ltd | Natural shrinkage preventing device for boom extension derricking cylinder |
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| Title |
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| PATENT ABSTRACTS OF JAPAN vol. 007, no. 227 (M - 248) 7 October 1983 (1983-10-07) * |
| PATENT ABSTRACTS OF JAPAN vol. 096, no. 005 31 May 1996 (1996-05-31) |
Also Published As
| Publication number | Publication date |
|---|---|
| DE19716081C1 (en) | 1998-08-13 |
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