EP0141106B1 - Working cylinder having three positions - Google Patents

Working cylinder having three positions Download PDF

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Publication number
EP0141106B1
EP0141106B1 EP84109969A EP84109969A EP0141106B1 EP 0141106 B1 EP0141106 B1 EP 0141106B1 EP 84109969 A EP84109969 A EP 84109969A EP 84109969 A EP84109969 A EP 84109969A EP 0141106 B1 EP0141106 B1 EP 0141106B1
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EP
European Patent Office
Prior art keywords
piston
seal
pistons
stop
working cylinder
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
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EP84109969A
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German (de)
French (fr)
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EP0141106A3 (en
EP0141106A2 (en
Inventor
Alfred Ing.-Grad. Klatt
Karlheinz Brinkmann
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Wabco Westinghouse Fahrzeugbremsen GmbH
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Wabco Westinghouse Fahrzeugbremsen GmbH
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Priority to AT84109969T priority Critical patent/ATE26328T1/en
Publication of EP0141106A2 publication Critical patent/EP0141106A2/en
Publication of EP0141106A3 publication Critical patent/EP0141106A3/en
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Publication of EP0141106B1 publication Critical patent/EP0141106B1/en
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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
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/08—Servomotor systems without provision for follow-up action; Circuits therefor with only one servomotor
    • F15B11/12—Servomotor systems without provision for follow-up action; Circuits therefor with only one servomotor providing distinct intermediate positions; with step-by-step action
    • F15B11/121—Servomotor systems without provision for follow-up action; Circuits therefor with only one servomotor providing distinct intermediate positions; with step-by-step action providing distinct intermediate positions
    • F15B11/123—Servomotor systems without provision for follow-up action; Circuits therefor with only one servomotor providing distinct intermediate positions; with step-by-step action providing distinct intermediate positions by means of actuators with fluid-operated stops

Definitions

  • the invention relates to a working cylinder with three positions according to the preamble of claim 1.
  • Such a working cylinder is known from DE-A-3 107 908.
  • a first piston provided with a piston rod, which divides the cylinder into a first pressure medium chamber on the piston rod side and a second pressure medium chamber arranged on the other side of the piston with respect to the first pressure medium chamber.
  • a second piston designed as an annular piston is arranged such that it can be moved and sealed.
  • the second piston is movable against a gradation of the cylinder housing that fixes the central position.
  • Two stops are provided on the first piston which serve to limit the relative movement between the two pistons in that the second piston can be moved between them relative to the first piston.
  • the outer stop arranged in the end region of the first piston prevents the second piston from detaching from the first piston when the first piston is actuated by means of the piston rod when the cylinder is depressurized.
  • This stop like the other stop, is designed as a circlip. This means that when assembling the known working cylinder, the ring piston must first be pushed onto the first piston and then the circlip must be attached for the abovementioned stop.
  • the invention has for its object to provide a cylinder of the type mentioned, in which the assembly is simplified.
  • the invention has the particular advantage that when the working cylinder is assembled, the two pistons are connected by simply pushing the second piston onto the first piston, a projection arranged on the second piston being a snap connection over the one arranged on the first piston as a stop serving sealing element is guided.
  • the expenditure on components and labor is reduced, since the stop and the sealing element consist of a single component and it is therefore no longer necessary to incorporate an additional groove into the piston for receiving a retaining ring serving as a stop. For this reason, no special tools for heating a circlip are required.
  • the two pistons cooperate telescopically and the two stops, which prevent the two pistons from unintentionally detaching from one another, are arranged between the outer surface of one piston and the inner wall of the other piston facing the outer surface, the overall length of the cylinder is reduced.
  • the illustration shows a working cylinder with three positions on average.
  • a first piston 18, 15 provided with a piston rod 3 is displaceably arranged in a cylinder 14, which is closed by a cover 25 with the interposition of a sealing ring 28, a first piston 18, 15 provided with a piston rod 3 is displaceably arranged.
  • the first piston 18, 15 divides the cylinder into a first pressure medium chamber 2 on the piston rod side and a second pressure medium chamber 17 located on the other side of the piston 18, 15 with respect to the first pressure medium chamber 2.
  • the two pressure medium chambers 2 and 17 are each connected via a pressure medium connection 24 or 16 and a valve device, not shown, can be aerated and vented.
  • the first piston 18, 15 has on its side facing the second pressure medium chamber 17 a spherical guide 15.
  • a seal designed as a groove ring 12 is mounted in a groove 13, the flanks of which are formed, on the one hand, by the spherical guide 15 and, on the other hand, by a circumferential projection of the piston 15, 18 serving as a stop 11, a seal designed as a groove ring 12 is mounted.
  • the groove ring 12 seals the second pressure medium chamber 17 against the first pressure medium chamber 2.
  • a second piston 7 designed as an annular piston is arranged so as to be displaceable relative to the first piston 15, 18.
  • the second piston 7 has a radially outwardly extending circumferential projection 6, with which the second piston 7 can be brought into contact with a stop 19 fixed to the housing during a movement in the direction of the second pressure medium chamber 17.
  • the stop 19 fixed to the housing is formed by a gradation of the cylinder 14 and serves to fix the two pistons 15, 18; 7 in the middle position.
  • the groove ring 5 seals the first pressure medium chamber 2 against the second pressure medium chamber 17 7.
  • an additional seal designed as a grooved ring 22 is arranged between the outer surface of the first piston 15, 18 and the inner wall of the second piston 7.
  • the second grooved ring 22 is supported in a groove 23 provided in the lateral surface of the first piston 15, 18, which is provided in the end region of the first piston 15, 18 facing the first pressure medium chamber 2.
  • the second piston 7 has a preferably circumferential projection 8, 9, 10, which extends radially inward in the direction of the lateral surface of the first piston 15, 18.
  • the projection serves as a stop, which cooperates with the stop arranged on the first piston 15, 18 and formed by the sealing ring 22.
  • the stop 8, 9, 10 has on its side facing the sealing ring 22 a steep edge 8 and on its side facing away from the sealing ring 22 has a ramp-shaped bevel 10.
  • a recess 27 is provided in the cover 25 of the cylinder 14, through which the piston rod 3 is guided out of the cylinder 14.
  • a sealing ring 26, which is mounted in a groove arranged in the wall of the recess 27 and bears sealingly against the piston rod 3, prevents pressure medium from escaping from the first pressure medium chamber 2 through the recess 27 to the atmosphere.
  • the space between the two pistons 15, 18; 7 is connected to the atmosphere via a breathing hole 20.
  • the second piston 7, which is designed as an annular piston, is pushed onto the first piston 15, 18 from the piston rod end of the first piston 15, 18.
  • the groove ring 22 is elastically deformed by the stop 8, 9, 10 of the second piston 7. If the stop 8, 9, 10 has run over the grooved ring 22, the grooved ring 22 regains its original shape.
  • the second piston 7 can be pushed onto the first piston 15, 18 without the use of special tools, since the stop 8, 9, 10 arranged on the second piston 7 has a ramp-shaped bevel 10 which, when the second piston 7 is pushed onto the first piston 15, 18 deformed the ring nut 22 in a manner that is gentle on the material. Separation of the two pistons 7; 15, 18 is only possible without the use of special tools if damage to the grooved ring 22 is accepted, since the side of the stop 8, 9, 10 facing the grooved ring after assembly is designed as a steep edge 8.
  • the function of the working cylinder described above is explained in more detail below. It is assumed that the first piston 15, 18 connected to the piston rod 3, as shown in the figure, has assumed the central position. Pressure is present in the first pressure medium chamber 2 and in the second pressure medium chamber 17 via the pressure medium connections 24, 16. The pressures in the two pressure medium chambers 2, 17 are the same. The second piston 7 is pressed against the stop 19 fixed to the housing and remains at rest. The first piston 15, 18 is pressed with its stop 11 against the second piston 7. Since the sum of the effective surfaces of the two pistons 15, 18; 7 is larger than the opposing active surface of the first piston 15, 18 which is acted upon by the pressure from the second pressure medium chamber 17, the first piston 15, 18 connected to the piston rod 3 remains in the central position.
  • the first piston 15, 18 connected to the piston rod 3 is to be brought into its left end position, the first pressure medium chamber 2 is vented.
  • the first piston 15, 18 is shifted to the left by the pressure from the second pressure medium chamber 17 and takes the second piston 7 with it with its stop 11.
  • first piston 15, 18 is to be brought into its right end position and the piston rod 3 is to be moved into the cylinder 14, the second pressure medium chamber 17 is vented and the first pressure medium chamber 2 is vented. Both the first piston 15, 18 and the second piston 7 are moved toward the second pressure medium chamber 17 by the pressure from the first pressure medium chamber 2. The second piston 7 comes to rest with its projection 6 on the stop 19 fixed to the housing and the first piston 15, 18 continues to its right end position.
  • the second pressure medium chamber 17 is again pressurized.
  • the first piston 15, 18 is moved by the pressure medium from the second pressure medium chamber 17 to the left in the direction of the first pressure medium chamber 2 until it comes to rest with its stop 11 on the end face of the second piston 7 facing it.
  • first piston 15, 18 and the second piston 7 are in their left end position and the first piston 15, 18 is moved to the right in the direction of the second pressure medium chamber 17 by means of the piston rod 3 when the cylinder is depressurized, the first piston 15 comes , 18 with its grooved ring 22 against the steep edge 8 of the stop 8, 9, 10 arranged on the second piston 7 and takes the second piston 7 with it.
  • An unintentional separation of the two pistons 15, 18; 7 is therefore excluded, so that the function is ensured when the working cylinder is put into operation again.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Actuator (AREA)
  • Forklifts And Lifting Vehicles (AREA)
  • Lifting Devices For Agricultural Implements (AREA)
  • Harvester Elements (AREA)

Abstract

1. Three-position working cylinder having the following features : a) there is provided a first piston (15, 18) which is provided with an operating member (3) and is guided in sealed manner in a cylinder (14) ; b) there is provided a second piston (7), constructed in the form of an annular piston, which is guided in sealed manner with respect to the inner wall of the cylinder and with respect to an outer surface of the first piston (15, 18) ; c) there is provided a stop (19) which is fixed with respect to the housing and limits the travel of the second piston (7) ; d) in order to limit the relative movement between the first piston (15, 18) and the second pisotn (7), each of those pistons has for each direction of movement stop (11, 12) that cooperates with a corresponding further stop (8, 9, 10) on the other piston, characterized by the following features : e) one of the stops is formed by a seal (22) arranged between the two pistons (15, 18 ; 7) ; f) the associated further stop (8, 9, 10) that cooperates with the seal (22) in order to limit the relative movement of the two pistons (15, 18 ; 7) is constructed in such a manner that it can be guided over the seal (22) in the manner of a snap connection when two pistons (15, 18 ; 7) are joined together.

Description

Die Erfindung betrifft einen Arbeitszylinder mit drei Stellungen gemäss dem Oberbegriff des Patentanspruchs 1.The invention relates to a working cylinder with three positions according to the preamble of claim 1.

Ein derartiger Arbeitszylinder ist aus der DE-A-3 107 908 bekannt. In einem Zylinder ist ein mit einer Kolbenstange versehener erster Kolben angeordnet, welcher den Zylinder in eine kolbenstangenseitige erste Druckmittelkammer und eine bezüglich der ersten Druckmittelkammer auf der anderen Seite des Kolbens angeordnete zweite Druckmittelkammer unterteilt. Auf dem ersten Kolben ist ein als Ringkolben ausgebildeter zweiten Kolben abgedichtet verschiebbar angeordnet. Der zweite Kolben ist gegen eine die Mittelstellung fixierende Abstufung des Zylindergehäuses bewegbar. Auf dem ersten Kolben sind zwei Anschläge vorgesehen, die dadurch zur Begrenzung der Relativbewegung zwischen den beiden Kolben dienen, dass der zweite Kolben zwischen ihnen relativ zum ersten Kolben bewegbar ist. Der im Endbereich des ersten Kolbens angeordnete äussere Anschlag verhindert bei einer Betätigung des ersten Kolbens mittels der Kolbenstange bei drucklosem Zylinder ein Lösen des zweiten Kolbens vom ersten Kolben. Dieser Anschlag ist wie auch der andere Anschlag als Seegerring ausgebildet. Dies bedeutet, dass bei der Montage des bekannten Arbeitszylinders erst der Ringkolben auf den ersten Kolben aufgeschoben werden muss und dass dann der Seegerring für den erwähnten Anschlag angebracht werden muss.Such a working cylinder is known from DE-A-3 107 908. Arranged in a cylinder is a first piston provided with a piston rod, which divides the cylinder into a first pressure medium chamber on the piston rod side and a second pressure medium chamber arranged on the other side of the piston with respect to the first pressure medium chamber. On the first piston, a second piston designed as an annular piston is arranged such that it can be moved and sealed. The second piston is movable against a gradation of the cylinder housing that fixes the central position. Two stops are provided on the first piston which serve to limit the relative movement between the two pistons in that the second piston can be moved between them relative to the first piston. The outer stop arranged in the end region of the first piston prevents the second piston from detaching from the first piston when the first piston is actuated by means of the piston rod when the cylinder is depressurized. This stop, like the other stop, is designed as a circlip. This means that when assembling the known working cylinder, the ring piston must first be pushed onto the first piston and then the circlip must be attached for the abovementioned stop.

Der Erfindung liegt die Aufgabe zugrunde, einen Arbeitszylinder der eingangs erwähnten Art zu schaffen, bei dem die Montage vereinfacht ist.The invention has for its object to provide a cylinder of the type mentioned, in which the assembly is simplified.

Diese Aufgabe wird mit der im Patentanspruch 1 angegebenen Erfindung gelöst. Weiterbildungen und vorteilhafte Ausgestaltungen der Erfindung sind in den Unteransprüchen angegeben.This object is achieved with the invention specified in claim 1. Further developments and advantageous refinements of the invention are specified in the subclaims.

Die Erfindung bietet insbesondere den Vorteil, dass bei der Montage des Arbeitszylinders die Verbindung der beiden Kolben durch einfaches Aufschieben des zweiten Kolbens auf den ersten Kolben erfolgt, wobei ein am zweiten Kolben angeordneter Vorsprung nach Art einer Schnappverbindung über das auf dem ersten Kolben angeordnete als Anschlag dienende Dichtelement geführt wird. Der Bauteile-und Arbeitsaufwand wird verringert, da Anschlag und Dichtelement aus einem einzigen Bauteil bestehen und es somit nicht mehr erforderlich ist, eine zusätzliche Nut zur Aufnahme eines als Anschlag dienenden Sicherungsringes in den Kolben einzuarbeiten. Es sind aus diesem Grund auch keine speziellen Werkzeuge zum Aufheizen eines Sicherungsringes mehr erforderlich.The invention has the particular advantage that when the working cylinder is assembled, the two pistons are connected by simply pushing the second piston onto the first piston, a projection arranged on the second piston being a snap connection over the one arranged on the first piston as a stop serving sealing element is guided. The expenditure on components and labor is reduced, since the stop and the sealing element consist of a single component and it is therefore no longer necessary to incorporate an additional groove into the piston for receiving a retaining ring serving as a stop. For this reason, no special tools for heating a circlip are required.

Da die beiden Kolben teleskopartig zusammenwirken und die beiden Anschläge, welche ein unbeabsichtigtes Lösen der beiden Kolben voneinander verhindern, zwischen der Mantelfläche des einen Kolbens und der der Mantelfläche zugewandten Innenwand des anderen Kolbens angeordnet sind, verringert sich die Baulänge des Zylinders.Since the two pistons cooperate telescopically and the two stops, which prevent the two pistons from unintentionally detaching from one another, are arranged between the outer surface of one piston and the inner wall of the other piston facing the outer surface, the overall length of the cylinder is reduced.

Anhand der Abbildung wird nachstehend ein Ausführungsbeispiel der Erfindung näher erläutert.An exemplary embodiment of the invention is explained in more detail below with the aid of the figure.

Die Abbildung zeigt einen Arbeitszylinder mit drei Stellungen im Schnitt.The illustration shows a working cylinder with three positions on average.

In einem Zylinder 14, welcher unter Zwischenschalten eines Dichtringes 28 von einem Deckel 25 verschlossen wird, ist ein mit einer Kolbenstange 3 versehener erster Kolben 18, 15 verschiebbar angeordnet. Der erste Kolben 18, 15 unterteilt den Zylinder in eine kolbenstangenseitige erste Druckmittelkammer 2 und eine bezüglich der ersten Druckmittelkammer 2 auf der anderen Seite des Kolbens 18, 15 liegende zweite Druckmittelkammer 17. Die beiden Druckmittelkammern 2 und 17 sind über je einen Druckmittelanschluss 24 bzw. 16 und eine nicht dargestellte Ventileinrichtung be- und entlüftbar. Der erste Kolben 18, 15 weist auf seiner der zweiten Druckmittelkammer 17 zugewandten Seite eine ballig ausgebildete umlaufende Führung 15 auf. In einer Nut 13, deren Flanken einerseits von der balligen Führung 15 und andererseits von einem Anschlag 11 dienenden umlaufenden Vorsprung des Kolbens 15, 18 gebildet werden, ist eine als Nutring 12 ausgebildete Dichtung gelagert. Der Nutring 12 dichtet die zweite Druckmittelkammer 17 gegen die erste Druckmittelkammer 2 ab.In a cylinder 14, which is closed by a cover 25 with the interposition of a sealing ring 28, a first piston 18, 15 provided with a piston rod 3 is displaceably arranged. The first piston 18, 15 divides the cylinder into a first pressure medium chamber 2 on the piston rod side and a second pressure medium chamber 17 located on the other side of the piston 18, 15 with respect to the first pressure medium chamber 2. The two pressure medium chambers 2 and 17 are each connected via a pressure medium connection 24 or 16 and a valve device, not shown, can be aerated and vented. The first piston 18, 15 has on its side facing the second pressure medium chamber 17 a spherical guide 15. In a groove 13, the flanks of which are formed, on the one hand, by the spherical guide 15 and, on the other hand, by a circumferential projection of the piston 15, 18 serving as a stop 11, a seal designed as a groove ring 12 is mounted. The groove ring 12 seals the second pressure medium chamber 17 against the first pressure medium chamber 2.

Auf dem ersten Kolben 15, 18 ist ein als Ringkolben ausgebildeter zweiter Kolben 7 relativ zum ersten Kolben 15, 18 verschiebbar angeordnet. Der zweite Kolben 7 besitzt einen sich radial nach aussen erstreckenden umlaufenden Vorsprung 6, mit welchem der zweite Kolben 7 bei einer Bewegung in Richtung auf die zweite Druckmittelkammer 17 zu an einem gehäusefesten Anschlag 19 zur Anlage bringbar ist. Der gehäusefeste Anschlag 19 wird von einer Abstufung des Zylinders 14 gebildet und dient zur Fixierung der beiden Kolben 15, 18; 7 in der Mittelstellung. In einer Nut 4 des zweiten Kolbens 7, deren Flanken einerseits vom Vorsprung 6 und andererseits von einem weiteren umlaufenden Vorsprung 21, welcher an der der ersten Druckmittelkammer 2 zugewandten Seite des zweiten Kolbens 7 vorgesehen ist, gebildet werden, ist eine als Nutring 5 ausgebildete Dichtung gelagert. Der Nutring 5 dichtet die erste Druckmittelkammer 2 gegen die zweite Druckmittelkammer 17 7 ab.On the first piston 15, 18, a second piston 7 designed as an annular piston is arranged so as to be displaceable relative to the first piston 15, 18. The second piston 7 has a radially outwardly extending circumferential projection 6, with which the second piston 7 can be brought into contact with a stop 19 fixed to the housing during a movement in the direction of the second pressure medium chamber 17. The stop 19 fixed to the housing is formed by a gradation of the cylinder 14 and serves to fix the two pistons 15, 18; 7 in the middle position. In a groove 4 of the second piston 7, the flanks of which are formed on the one hand by the projection 6 and on the other hand by a further circumferential projection 21, which is provided on the side of the second piston 7 facing the first pressure medium chamber 2, is a seal designed as a groove ring 5 stored. The groove ring 5 seals the first pressure medium chamber 2 against the second pressure medium chamber 17 7.

Zur Abdichtung des Raumes zwischen den beiden teleskopartig zusammenwirkenden Kolben 15, 18; 7 ist eine zusätzliche als Nutring 22 ausgebildete Dichtung zwischen der Mantelfläche des ersten Kolbens 15, 18 und der Innenwand des zweiten Kolbens 7 angeordnet. Der zweite Nutring 22 ist in diesem Ausführungsbeispiel in einer in der Mantelfläche des ersten Kolbens 15, 18 vorgesehenen Nut 23 gelagert, welche in dem der ersten Druckmittelkammer 2 zugewandten Endbereich des ersten Kolbens 15, 18 vorgesehen ist. Der zweite Kolben 7 weist in seinem dem ersten Kolben 15, 18 zugewandten Endbereich einen sich radial nach innen in Richtung auf die Mantelfläche des ersten Kolbens 15, 18 zu erstreckenden, vorzugsweise umlaufenden Vorsprung 8, 9, 10 auf. Der Vorsprung dient als Anschlag, weicher mit dem auf dem ersten Kolben 15, 18 angeordneten, vom Dichtring 22 gebildeten Anschlag zusammenwirkt.To seal the space between the two telescopically interacting pistons 15, 18; 7, an additional seal designed as a grooved ring 22 is arranged between the outer surface of the first piston 15, 18 and the inner wall of the second piston 7. In this exemplary embodiment, the second grooved ring 22 is supported in a groove 23 provided in the lateral surface of the first piston 15, 18, which is provided in the end region of the first piston 15, 18 facing the first pressure medium chamber 2. In its end region facing the first piston 15, 18, the second piston 7 has a preferably circumferential projection 8, 9, 10, which extends radially inward in the direction of the lateral surface of the first piston 15, 18. The projection serves as a stop, which cooperates with the stop arranged on the first piston 15, 18 and formed by the sealing ring 22.

Der Anschlag 8, 9, 10 weist auf seiner dem Dichtring 22 zugewandten Seite eine steile Kante 8 und auf seiner dem Dichtring 22 abgewandten Seite eine rampenförmige Abschrägung 10 auf.The stop 8, 9, 10 has on its side facing the sealing ring 22 a steep edge 8 and on its side facing away from the sealing ring 22 has a ramp-shaped bevel 10.

Im Deckel 25 des Zylinders 14 ist eine Ausnehmung 27 vorgesehen, durch welche die Kolbenstange 3 aus dem Zylinder 14 herausgeführt wird. Ein Dichtring 26, der in einer in der Wandung der Ausnehmung 27 angeordneten Nut gelagert ist und dichtend an der Kolbenstange 3 anliegt, verhindert ein Austreten von Druckmittel aus der ersten Druckmittelkammer 2 durch die Ausnehmung 27 zur Atmosphäre hin. Der Raum zwischen den beiden Kolben 15, 18; 7 ist über eine Atmungsbohrung 20 mit der Atmosphäre verbunden.A recess 27 is provided in the cover 25 of the cylinder 14, through which the piston rod 3 is guided out of the cylinder 14. A sealing ring 26, which is mounted in a groove arranged in the wall of the recess 27 and bears sealingly against the piston rod 3, prevents pressure medium from escaping from the first pressure medium chamber 2 through the recess 27 to the atmosphere. The space between the two pistons 15, 18; 7 is connected to the atmosphere via a breathing hole 20.

Bei der Montage des Arbeitszylinders wird der als Ringkolben ausgebildete zweite Kolben 7 von der kolbenstangenseitigen Stirnseite des ersten Kolbens 15, 18 her auf den ersten Kolben 15, 18 aufgeschoben. Dabei wird der Nutring 22 vom Anschlag 8, 9, 10 des zweiten Kolbens 7 elastisch verformt. Hat der Anschlag 8, 9, 10 den Nutring 22 überfahren, so erlangt der Nutring 22 seine ursprüngliche Form wieder. Das Aufschieben des zweiten Kolbens 7 auf den ersten Kolben 15, 18 kann ohne die Verwendung von speziellen Werkzeugen erfolgen, da der am zweiten Kolben 7 angeordnete Anschlag 8, 9, 10 eine rampenförmige Schräge 10 aufweist, welche beim Aufschieben des zweiten Kolbens 7 auf den ersten Kolben 15, 18 den Nutring 22 materialschonend verformt. Ein Trennen der beiden Kolben 7; 15, 18 ist ohne den Einsatz von speziellen Werkzeugen nur möglich, wenn eine Beschädigung des Nutringes 22 in Kauf genommen wird, da die nach der Montage dem Nutring zugewandte Seite des Anschlages 8, 9, 10 als steile Kante 8 ausgebildet ist.When the working cylinder is being assembled, the second piston 7, which is designed as an annular piston, is pushed onto the first piston 15, 18 from the piston rod end of the first piston 15, 18. The groove ring 22 is elastically deformed by the stop 8, 9, 10 of the second piston 7. If the stop 8, 9, 10 has run over the grooved ring 22, the grooved ring 22 regains its original shape. The second piston 7 can be pushed onto the first piston 15, 18 without the use of special tools, since the stop 8, 9, 10 arranged on the second piston 7 has a ramp-shaped bevel 10 which, when the second piston 7 is pushed onto the first piston 15, 18 deformed the ring nut 22 in a manner that is gentle on the material. Separation of the two pistons 7; 15, 18 is only possible without the use of special tools if damage to the grooved ring 22 is accepted, since the side of the stop 8, 9, 10 facing the grooved ring after assembly is designed as a steep edge 8.

Die Funktion des im vorstehenden beschriebenen Arbeitszylinders wird nachfolgend näher erläutert. Es wird angenommen, dass der mit der Kolbenstange 3 verbundene erste Kolben 15, 18, wie in der Abbildung dargestellt, die Mittelstellung eingenommen hat. Über die Druckmittelanschlüsse 24, 16 steht in der ersten Druckmittelkammer 2 und in der zweiten Druckmittelkammer 17 Druck an. Die Drücke in den beiden Druckmittelkammern 2, 17 sind gleich. Der zweite Kolben 7 wird gegen den gehäusefesten Anschlag 19 angedrückt und bleibt in Ruhe. Der erste Kolben 15, 18 wird mit seinem Anschlag 11 gegen den zweiten Kolben 7 angedrückt. Da die Summe der vom Druck aus der ersten Druckmittelkammer 2 beaufschlagten Wirkflächen der beiden Kolben 15, 18; 7 grösser ist als die vom Druck aus der zweiten Druckmittelkammer 17 beaufschlagte entgegengerichtete Wirkfläche des ersten Kolbens 15, 18 verbleibt der mit der Kolbenstange 3 verbundene erste Kolben 15, 18 in der Mittelsltellung.The function of the working cylinder described above is explained in more detail below. It is assumed that the first piston 15, 18 connected to the piston rod 3, as shown in the figure, has assumed the central position. Pressure is present in the first pressure medium chamber 2 and in the second pressure medium chamber 17 via the pressure medium connections 24, 16. The pressures in the two pressure medium chambers 2, 17 are the same. The second piston 7 is pressed against the stop 19 fixed to the housing and remains at rest. The first piston 15, 18 is pressed with its stop 11 against the second piston 7. Since the sum of the effective surfaces of the two pistons 15, 18; 7 is larger than the opposing active surface of the first piston 15, 18 which is acted upon by the pressure from the second pressure medium chamber 17, the first piston 15, 18 connected to the piston rod 3 remains in the central position.

Soll der mit der Kolbenstange 3 verbundene erste Kolben 15, 18 in seine linke Endlage gebracht werden, so wird die erste Druckmittelkammer 2 entlüftet. Vom Druck aus der zweiten Druckmittelkammer 17 wird der erste Kolben 15, 18 nach links verschoben und nimmt mit seinem Anschlag 11 den zweiten Kolben 7 mit.If the first piston 15, 18 connected to the piston rod 3 is to be brought into its left end position, the first pressure medium chamber 2 is vented. The first piston 15, 18 is shifted to the left by the pressure from the second pressure medium chamber 17 and takes the second piston 7 with it with its stop 11.

Soll der erste Kolben 15, 18 in seine rechte Endlage gebracht und so die Kolbenstange 3 in den Zylinder 14 eingefahren werden, wird die zweite Druckmittelkammer 17 entlüftet und die erste Druckmittelkammer 2 wird belüftet. Sowohl der erste Kolben 15, 18 als auch der zweite Kolben 7 werden vom Druck aus der ersten Druckmittelkammer 2 in Richtung auf die zweite Druckmittelkammer 17 zu bewegt. Der zweite Kolben 7 kommt mit seinem Vorsprung 6 am gehäusefesten Anschlag 19 zur Anlage und der erste Kolben 15, 18 fährt weiter bis in seine rechte Endlage.If the first piston 15, 18 is to be brought into its right end position and the piston rod 3 is to be moved into the cylinder 14, the second pressure medium chamber 17 is vented and the first pressure medium chamber 2 is vented. Both the first piston 15, 18 and the second piston 7 are moved toward the second pressure medium chamber 17 by the pressure from the first pressure medium chamber 2. The second piston 7 comes to rest with its projection 6 on the stop 19 fixed to the housing and the first piston 15, 18 continues to its right end position.

Wird wieder die neutrale Mittelstellung gewünscht, so wird auch die zweite Druckmittelkammer 17 wieder mit Druckmittel beaufschlagt. Der erste Kolben 15, 18 wird vom Druckmittel aus der zweiten Druckmittelkammer 17 nach links in Richtung auf die erste Druckmittelkammer 2 zu verschoben und zwar so weit, bis er mit seinem Anschlag 11 an der ihm zugewandten Stirnseite des zweiten Kolbens 7 zur Anlage kommt.If the neutral middle position is desired again, the second pressure medium chamber 17 is again pressurized. The first piston 15, 18 is moved by the pressure medium from the second pressure medium chamber 17 to the left in the direction of the first pressure medium chamber 2 until it comes to rest with its stop 11 on the end face of the second piston 7 facing it.

Befinden sich der erste Kolben 15, 18 und der zweite Kolben 7 in ihrer linken Endlage und der erste Kolben 15, 18 wird mittels der Kolbenstange 3 bei drucklosem Zylinder nach rechts in Richtung auf die zweite Druckmittelkammer 17 zu verschoben, so kommt der erste Kolben 15, 18 mit seinem Nutring 22 an der steilen Kante 8 des am zweiten Kolben 7 angeordneten Anschlages 8, 9, 10 zur Anlage und nimmt den zweiten Kolben 7 mit. Ein unbeabsichtigtes Trennen der beiden Kolben 15, 18; 7 ist somit ausgeschlossen, so dass bei wieder in Betriebnahme des Arbeitszylinders die Funktion sichergestellt ist.If the first piston 15, 18 and the second piston 7 are in their left end position and the first piston 15, 18 is moved to the right in the direction of the second pressure medium chamber 17 by means of the piston rod 3 when the cylinder is depressurized, the first piston 15 comes , 18 with its grooved ring 22 against the steep edge 8 of the stop 8, 9, 10 arranged on the second piston 7 and takes the second piston 7 with it. An unintentional separation of the two pistons 15, 18; 7 is therefore excluded, so that the function is ensured when the working cylinder is put into operation again.

Claims (6)

1. Three-position working cylinder having the following features:
a) there is provided a first piston (15, 18) which is provided with an operating member (3) and is guided in sealed manner in a cylinder (14);
b) there is provided a second piston (7), constructed in the form of an annular piston, which is guided in sealed manner with respect to the inner wall of the cylinder and with respect to an outer surface of the first piston (15, 18);
c) there is provided a stop (19) which is fixed with respect to the housing and limits the travel of the second piston (7);
d) in order to limitthe relative movement between the first piston (15, 18) and the second piston (7), each of those pistons has for each direction of movement stop (11, 12) that cooperates with a corresponding further stop (8, 9, 10) on the other piston, characterised by the following features:
e) one of the stops is formed by a seal (22) arranged between the two pistons (15, 18; 7);
f) the associated further stop (8, 9, 10) that cooperates with the seal (22) in order to limit the relative movement of the two pistons (15, 18; 7) is constructed in such a manner that it can be guided over the seal (22) in the manner of a snap connection when the two pistons (15, 18; 7) are joined together.
2. Working cylinder according to claim 1, characterised in that the associated further stop (8, 9, 10) that cooperates with the seal (22) in orderto limit the relative movement of the two pistons (15, 18; 7) is constructed in the form of a circumferential projection which has on its side facing the seal (22) a steep edge (8) and on its side remote from the seal (22) a ramp-like inclined surface (10).
3. Working cylinder according to claim 1, characterised in that the seal (22) is constructed in the form of a grooved ring.
4. Working cylinder according to at least one of the preceding claims, characterised by the following features:
a) the stop formed by the seal (22) is arranged on the outer surface of the first piston (15, 18);
b) the associated further stop (8, 9, 10) that cooperates with the seal (22) in order to limit the relative movement of the two pistons (15, 18; 7) is arranged on the inner wall of the second piston (7) that faces the first piston (15, 18).
5. Working cylinder according to claim 1, characterised in that the associated further stop that cooperates with the seal (22) in order to limit the relative movement of the two pistons (15, 18; 7) is formed by at least one spring element.
6. Working cylinder according to claim 1, characterised in that the associated further stop that cooperates with the seal (22) in order to limit the relative movement of the two pistons (15,18; 7) is resiliently mounted.
EP84109969A 1983-10-08 1984-08-22 Working cylinder having three positions Expired EP0141106B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT84109969T ATE26328T1 (en) 1983-10-08 1984-08-22 POWER CYLINDER WITH THREE POSITIONS.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3336682 1983-10-08
DE19833336682 DE3336682A1 (en) 1983-10-08 1983-10-08 WORK CYLINDER WITH THREE POSITIONS

Publications (3)

Publication Number Publication Date
EP0141106A2 EP0141106A2 (en) 1985-05-15
EP0141106A3 EP0141106A3 (en) 1985-11-06
EP0141106B1 true EP0141106B1 (en) 1987-04-01

Family

ID=6211367

Family Applications (1)

Application Number Title Priority Date Filing Date
EP84109969A Expired EP0141106B1 (en) 1983-10-08 1984-08-22 Working cylinder having three positions

Country Status (4)

Country Link
EP (1) EP0141106B1 (en)
AT (1) ATE26328T1 (en)
DE (2) DE3336682A1 (en)
YU (1) YU44879B (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4128389A1 (en) * 1991-08-27 1993-03-04 Grau Gmbh Double acting cylinder with ring piston and central piston - with dimensioning of effective surfaces to ensure pistons can move to mid-point
DE102009029038A1 (en) * 2009-08-31 2011-03-03 Zf Friedrichshafen Ag Method for synchronization, servomotor and switching device with servomotor
DE102010011239A1 (en) * 2010-03-12 2011-09-15 GM Global Technology Operations LLC , (n. d. Ges. d. Staates Delaware) Fluidic, particularly hydraulic operating actuator element has cylinder housing, which has piston chamber and drivable piston interacting with actuating element
US10081522B2 (en) 2014-10-17 2018-09-25 Vehicle Service Group, Llc Hydraulic synchronizer
DE102020212525A1 (en) 2020-10-05 2022-04-07 Zf Friedrichshafen Ag Control cylinder with three control positions and radially nested pressure chambers

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Publication number Priority date Publication date Assignee Title
DE1576175B1 (en) * 1966-11-15 1971-12-23 Barkas Werke Veb Pressurized working cylinder with double-sided loading, especially for switching gearboxes for motor vehicles
US3433132A (en) * 1966-11-28 1969-03-18 F & E Mfg Co Vacuum motor
CS151966B1 (en) * 1970-07-10 1973-12-19
DE2318757A1 (en) * 1973-03-01 1974-09-19 Louis Mayer Sloping face road reflector stud - having plate with reflecting back set in sloping face
SE414527B (en) * 1978-11-07 1980-08-04 Volvo Ab CYLINDER WITH TWICE STEP, SPECIFICALLY A SWEAT CYLINDER
GB2042079B (en) * 1979-02-03 1983-01-12 Ford A T Stroke variation relay device
DE8105898U1 (en) * 1981-03-02 1982-04-08 Leibfried Maschinenbau Gmbh, 7033 Herrenberg Piston-cylinder unit
DE3107908A1 (en) * 1981-03-02 1982-09-16 Leibfried Maschinenbau Gmbh, 7033 Herrenberg Piston/cylinder unit
DE3212758A1 (en) * 1982-04-06 1983-10-06 Filmosto Projektion Frame, especially interchangeable frame for photographs

Also Published As

Publication number Publication date
DE3336682A1 (en) 1985-04-25
YU161484A (en) 1990-06-30
ATE26328T1 (en) 1987-04-15
DE3462938D1 (en) 1987-05-07
EP0141106A3 (en) 1985-11-06
EP0141106A2 (en) 1985-05-15
YU44879B (en) 1991-04-30

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