EP0157213A1 - End-of-stroke cushioning device - Google Patents

End-of-stroke cushioning device Download PDF

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Publication number
EP0157213A1
EP0157213A1 EP85102590A EP85102590A EP0157213A1 EP 0157213 A1 EP0157213 A1 EP 0157213A1 EP 85102590 A EP85102590 A EP 85102590A EP 85102590 A EP85102590 A EP 85102590A EP 0157213 A1 EP0157213 A1 EP 0157213A1
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EP
European Patent Office
Prior art keywords
cylinder
connecting line
piston
cylinders
check valve
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP85102590A
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German (de)
French (fr)
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EP0157213B1 (en
Inventor
Wolf Dipl.-Ing. Schneider
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.)
Caterpillar Motoren GmbH and Co KG
Original Assignee
Krupp Mak Maschinenbau GmbH
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Publication of EP0157213A1 publication Critical patent/EP0157213A1/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
    • B66C23/00—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes
    • B66C23/62—Constructional features or details
    • B66C23/84—Slewing gear
    • B66C23/86—Slewing gear hydraulically actuated
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
    • B66C23/00—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes
    • B66C23/54—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes with pneumatic or hydraulic motors, e.g. for actuating jib-cranes on tractors
    • B66C23/545—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes with pneumatic or hydraulic motors, e.g. for actuating jib-cranes on tractors with arrangements for avoiding dead centre problems during cylinder motion
    • 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
    • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/20—Other details, e.g. assembly with regulating devices
    • F15B15/22—Other details, e.g. assembly with regulating devices for accelerating or decelerating the stroke
    • F15B15/224—Other details, e.g. assembly with regulating devices for accelerating or decelerating the stroke having a piston which closes off fluid outlets in the cylinder bore by its own movement

Definitions

  • the invention relates to a device for end position damping for swivel mechanisms operated by hydraulic cylinders of work equipment, such as cranes and excavator arms, in which two cylinders act at mutually offset positions of a swivel drive circuit.
  • each cylinder has a sufficiently large effective lever arm when the other cylinder is in a dead center position.
  • the drive task is of course also solved if both cylinders or the associated piston rods are articulated at the same position of the swivel drive circuit, but act from different directions.
  • the damped entry into the end position of the swivel range according to the prior art is solved in such a way that the oil return flow from one or both cylinders is reduced by throttle valves which are activated by switching cams or electrical position switches on the swivel drive circuit, since only here is the absolute information whether the swivel mechanism is in one or the other end position so that the corresponding return can be throttled.
  • the aim is to throttle only the cylinder with the larger effective lever arm - the trailing cylinder - in each end position and not to influence the other cylinder in order to avoid unnecessary bearing forces.
  • Devices of this type require precise positioning of switching cams and switches on the swivel circle and are associated with a corresponding construction outlay at the hydraulic / mechanical interface. In addition, there is a security risk that at un precise positioning of the switching elements the end position damping is not effective.
  • the object of the invention is to provide a generic device which enables damping while avoiding a safety risk and ensures control without precise presetting or positioning of the control elements.
  • the end of the cylinder to be damped has a connecting line of the hydraulic system and a further connecting line with a throttle valve, a non-return valve blocking the outflow from the cylinder being arranged parallel to the throttle valve.
  • the damping function is completely placed in the area of the cylinders.
  • a favorable design is created in that the connecting line can be worn by the piston, while the further connecting line remains free.
  • Another embodiment consists in that the piston carries an upstream locking element which is arranged via springs and which cooperates with an end control chamber of the cylinder as a closure and the connecting line to be closed is connected to the control chamber.
  • the side of the cylinder to be damped has an additional damping chamber as an extension, to which an additional piston of smaller diameter arranged on the piston is assigned, forming a gap in the passage area, the connecting line of the hydraulic system having an unlockable check valve, while the further connecting line is on the additional Damping chamber is connected.
  • the damping effect can also be varied by unlocking one of the check valves and the trailing cylinder.
  • the gap between the additional piston and the damping chamber decrease as the end position is approximated by the dimensioning of the additional piston or the damping chamber.
  • the check valves can be unlocked by control elements on the swivel drive circuit depending on the dead center position of the cylinders by means of control elements in such a way that the check valve for the cylinder with the larger effective lever arm - trailing cylinder - remains locked. All that is required here is a rough changeover signal, which indicates which side of the dead center the swivel mechanism is on and thus gives the signal which check valve is to be unlocked.
  • a rough changeover signal which indicates which side of the dead center the swivel mechanism is on and thus gives the signal which check valve is to be unlocked.
  • a work implement 2 on a carrier platform 1 which can be adjusted about a pivot point 3 with a swivel range 4 from one end position to an end position 2 '.
  • the swivel area 4 comprises only a part of the full circle because, for example, the operator station 5 projects beyond the swivel plane of the implement 2 for reasons of visibility and operation.
  • the pivoting movement is effected by two hydraulic cylinders 6 and 7.
  • the cylinders 6, 7 are connected to the carrier platform 1, for example, on a common support and pivot pin 8.
  • the associated piston rods are offset at points 9 and 10 of the swivel drive circuit 11 for the implement 2.
  • the trailing cylinder (6 in the end position 2, 7 'in the end position 2') has the largest effective lever arm. End position damping must therefore be effective on these cylinders.
  • this is produced in that the cylinders 6 and 7 are provided on the sides 12 and 13 building the damping pressure with two connecting lines 14, 15 and 16, 17 each, which end in lines 18, 19.
  • the connecting lines 14 and 16 are shut off in the end region 20 of the piston path by the pistons 21, 22, so that the oil can only escape via the connecting line 15, 17 with built-in throttle valves 23, 24, as long as check valves 25, 26 lying in parallel to them do not unlock are.
  • the leading cylinder 7 has an unfavorably small effective lever arm, so that the throttling effect should be eliminated as far as possible.
  • the check valves 25, 26 are expediently unlocked hydraulically via lines 27, 28 and a 4/2-way valve 29 which, in the rest position, connects the check valve 26 to a pressure line 30 and unlocks it. If a switch 31 senses the change of the implement 2 via an internal dead center into the area of the other end position 2 'via a cam 32, then the valve 29 is switched to the other position by means of a magnet 33, so that the check valve 25 is now unlocked . In this way it is achieved that the cylinder (6,7) with the larger effective lever arm, i.e. the trailing cylinder, which applies end position damping. The area to be damped is clearly defined by the design, so that no unacceptable forces are built up in the respective leading cylinder 6 or 7.
  • the arrangement has the advantage that even if the pressure oil supply 30 fails for the unlocking process or if the switchover at valve 29 fails, the end position damping remains sufficiently effective.
  • FIG 3 shows a hydraulic cylinder 34 with two connecting lines 35, 36, in which the free connecting line 35 is not through the hydraulic system piston 37 itself, but is controlled via a spring element 38 attached to the piston and connected upstream blocking element 39.
  • the blocking element 39 is immersed in a corresponding annular space 40. The further extension of the piston 37 is therefore only possible via the damping throttle 41 or the unlocked check valve 42.
  • a cylinder 43 has an additional damping chamber 44 on the damping side, into which an additional piston 45 is immersed with little play in the region of the end position.
  • an arranged connecting line 46 is only partially effective depending on the position of the piston 47 and the additional piston 45 for part of the piston surface, namely the surface of the additional piston 45, with a very small gap between the additional piston 45 and the damping chamber 44 being virtually ineffective.
  • the damping effect is applied by the throttle valve 49 mounted in the additional connecting line 48, wherein the throttle valve 49 can be adjustable.
  • An unblockable check valve 50 is connected in parallel with the throttle valve 49, which allows the throttling effect to be canceled, for example as a function of the cylinder function.
  • Another damping option is provided by installing an additional p n check valve 51 in the connecting line 46.
  • the oil displaced by piston 47 is also pressed and passed through the gap between additional piston 45 and throttle chamber 44 additionally, the adjustable throttle 50.
  • the check valve 51 can be unlocked just like the valve 50 depending on the cylinder function. For example, it is possible to change the damping effect of the trailing cylinder by additionally unlocking one of the two check valves (50, 51).

Abstract

1. End of stroke cushioning device for traversing gears of working apparatus (2), like cranes and dredger arms, which are operated via hydraulic cylinders and in which two cylinders (6, 7; 34, 43) act on positions (9, 10) of a pivot drive circle (11) displaced relatively to each other, characterised in that the side (12, 13) of the cylinders (6, 7; 34; 43) to be cushioned comprises in its end region a connecting line (14, 16; 35; 46) of the hydraulic system and a further connecting line (15, 17; 36; 48) with a throttle valve (23, 24; 41; 49), a check valve (25, 26; 42; 50) shutting off the fluid discharge from the cylinder (6, 7; 34; 43) being arranged parallel to the throttle valve (23, 24; 41; 49), and that the check valves (25, 26; 42; 50) in dependency of the dead-centre position of the cylinders (6, 7) are unlockable via a sequence switch cam (32) at the pivot drive circle (11) by means of control elements (29, 31, 33) in such a manner that in each case the check valve for the cylinder (6 or 7) with the larger effective lever arm (lagging cylinder) remains shut off.

Description

Die Erfindung bezieht sich auf eine Einrichtung zur Endlagendämpfung für über hydraulische Zylinder betriebene Schwenkwerke von Arbeitsgeräten, wie Kräne und Baggerarme, bei denen zwei Zylinder an gegeneinander versetzten Positionen eines Schwenkantriebskreises angreifen.The invention relates to a device for end position damping for swivel mechanisms operated by hydraulic cylinders of work equipment, such as cranes and excavator arms, in which two cylinders act at mutually offset positions of a swivel drive circuit.

Bei diesen bekannten Schwenkantrieben mit Linearantrieb durch hydraulische Zylinder hat jeweils ein Zylinder einen ausreichend großen wirksamen Hebelarm, wenn der andere Zylinder in einer Totpunktstellung steht. Die Antriebsaufgabe wird natürlich auch gelöst, wenn beide Zylinder bzw. die zugehörigen Kolbenstangen an der gleichen Position des Schwenkantriebskreises angelenkt sind, aber aus unterschiedlichen Richtungen wirken. Bei Schwenkwerken dieser Art wird das gedämpfte Einlaufen in die Endlage des Schwenkbereiches gemäß dem Stand der Technik in der Weise gelöst, daß der Ölrückfluß von einem oder beiden Zylindern durch Drosselventile vermindert wird, die durch Schaltnocken bzw. elektrische Positionsschalter am Schwenkantriebskreis aktiviert werden, da nur hier die Absolutinformation vorliegt, ob das Schwenkwerk sich in der einen oder anderen Endlage befindet, so daß der entsprechende Rücklauf gedrosselt werden kann. Zusätzlich wird angestrebt, in jeder Endposition nur den Zylinder mit dem größeren wirksamen Hebelarm - den nachlaufenden Zylinder - zu drosseln und den jeweils anderen Zylinder nicht zu beeinflussen, um unnötige Lagerkräfte zu vermeiden.In these known rotary actuators with linear actuation by hydraulic cylinders, each cylinder has a sufficiently large effective lever arm when the other cylinder is in a dead center position. The drive task is of course also solved if both cylinders or the associated piston rods are articulated at the same position of the swivel drive circuit, but act from different directions. In swivel mechanisms of this type, the damped entry into the end position of the swivel range according to the prior art is solved in such a way that the oil return flow from one or both cylinders is reduced by throttle valves which are activated by switching cams or electrical position switches on the swivel drive circuit, since only here is the absolute information whether the swivel mechanism is in one or the other end position so that the corresponding return can be throttled. In addition, the aim is to throttle only the cylinder with the larger effective lever arm - the trailing cylinder - in each end position and not to influence the other cylinder in order to avoid unnecessary bearing forces.

Derartige Einrichtungen erfordern eine genaue Positionierung von Schaltnocken und Schaltern auf dem Schwenkkreis und sind mit entsprechendem Bauaufwand an der Schnittstelle Hydraulik/Mechanik verbunden. Außerdem tritt hierbei ein Sicherheitsrisiko ein, daß bei ungenauer Positionierung der Schaltelemente die Endlagendämpfung nicht wirksam wird.Devices of this type require precise positioning of switching cams and switches on the swivel circle and are associated with a corresponding construction outlay at the hydraulic / mechanical interface. In addition, there is a security risk that at un precise positioning of the switching elements the end position damping is not effective.

Die Aufgabe der Erfindung ist es, eine gattungsgemäße Einrichtung zu schaffen, die eine Dämpfung unter Vermeidung eines Sicherheitsrisikos ermöglicht und eine Ansteuerung ohne genaue Voreinstellung bzw. Positionierung der Steuerelemente gewährleistet.The object of the invention is to provide a generic device which enables damping while avoiding a safety risk and ensures control without precise presetting or positioning of the control elements.

Die Lösung dieser Aufgabe erfolgt erfindungsgemäß dadurch, daß die zu dämpfende Seite des Zylinders in ihrem Endbereich eine Verbindungsleitung des Hydrauliksystems und eine weitere Verbindungsleitung mit einem Drosselventil aufweist, wobei parallel zum Drosselventil ein den Abfluß aus dem Zylinder sperrendes Rückschlagventil angeordnet ist.This object is achieved according to the invention in that the end of the cylinder to be damped has a connecting line of the hydraulic system and a further connecting line with a throttle valve, a non-return valve blocking the outflow from the cylinder being arranged parallel to the throttle valve.

Hierdurch wird die Dämpfungsfunktion vollständig in den Bereich der Zylinder gelegt. Eine günstige Ausbildung wird dadurch geschaffen, daß die Verbindungsleitung durch den Kolben verschlißebar ist, während die weitere Verbindungsleitung freibleibt.As a result, the damping function is completely placed in the area of the cylinders. A favorable design is created in that the connecting line can be worn by the piston, while the further connecting line remains free.

Eine weitere Ausführungsform besteht darin, daß der Kolben ein über Federn angeordnetes vorgeschaltetes Sperrelement trägt, das mit einer stirnseitigen Steuerkammer des Zylinders als Abschluß zusammenwirkt und an die Steuerkammer die zu verschließende Verbindungsleitung angeschlossen ist.Another embodiment consists in that the piston carries an upstream locking element which is arranged via springs and which cooperates with an end control chamber of the cylinder as a closure and the connecting line to be closed is connected to the control chamber.

Weiterhin wird vorgeschlagen, daß die zu dämpfende Seite des Zylinders eine zusätzliche Dämpfungskammer als Verlängerung aufweist, der ein am Kolben angeordneter Zusatzkolben kleineren Durchmessers unter Bildung eines Spaltes im Durchtrittsbereich zugeordnet ist, wobei die Verbindungsleitung des Hydrauliksystems ein entsperrbares Rückschlagventil aufweist, während die weitere Verbindungsleitung an der zusätzlichen Dämpfungskammer angeschlossen ist. Dabei ergibt sich der weitere Vorzug, daß die Dämpfungswirkung durch Entsperrung eines der Rückschlagventile auch des nachlaufenden Zylinders zusätzlich variiert werden kann.It is further proposed that the side of the cylinder to be damped has an additional damping chamber as an extension, to which an additional piston of smaller diameter arranged on the piston is assigned, forming a gap in the passage area, the connecting line of the hydraulic system having an unlockable check valve, while the further connecting line is on the additional Damping chamber is connected. There is the further advantage that the damping effect can also be varied by unlocking one of the check valves and the trailing cylinder.

Zur weiteren Verbesserung wird vorgeschlagen, daß der Spalt zwischen Zusatzkolben und Dämpfungskammer mit Annäherung an die Endlage durch die Dimensionierung des Zusatzkolbens oder der Dämpfungskammer abnimmt.For further improvement, it is proposed that the gap between the additional piston and the damping chamber decrease as the end position is approximated by the dimensioning of the additional piston or the damping chamber.

In Ausgestaltung der Erfindung ist vorgesehen, daß die Rückschlagventile in Abhängigkeit der Totpunktlage der Zylinder über einen Steuernocken am Schwenkantriebskreis durch Steuerelemente in der Weise entsperrbar sind, daß jeweils das Rückschlagventil für den Zylinder mit dem größeren wirksamen Hebelarm - nachlaufender Zylinder - gesperrt bleibt. Hierbei wird lediglich ein grobes Umschaltsignal erforderlich, das anzeigt, auf welcher Seite des Totpunktes sich das Schwenkwerk befindet und damit das Signal gibt, welches Rückschlagventil entsperrt werden soll. Der Vorteil dieser Anordnung ist es, daß bei Störungen durch nicht völlige Durchschalten des Ventils oder bei einem Versagen, immer beide Zylinder gedämpft werden und somit kein Sicherheitsrisiko besteht.In an embodiment of the invention it is provided that the check valves can be unlocked by control elements on the swivel drive circuit depending on the dead center position of the cylinders by means of control elements in such a way that the check valve for the cylinder with the larger effective lever arm - trailing cylinder - remains locked. All that is required here is a rough changeover signal, which indicates which side of the dead center the swivel mechanism is on and thus gives the signal which check valve is to be unlocked. The advantage of this arrangement is that in the event of malfunctions due to incomplete switching of the valve or failure, both cylinders are always damped and there is therefore no safety risk.

In der Zeichnung sind Ausführungsbeispiele der Erfindung schematisch dargestellt. Es zeigen:

  • Figur 1 eine Draufsicht auf ein Schwenkwerk,
  • Figur 2 eine Prinzipschaltungsanordnung,
  • Figur 3 einen Zylinder mit einer Ausführungsform einer Steuereinrichtung,
  • Figur 4 einen Zylinder mit einer weiteren Ausführungsform einer Steuereinrichtung.
Exemplary embodiments of the invention are shown schematically in the drawing. Show it:
  • FIG. 1 shows a top view of a swivel mechanism,
  • FIG. 2 shows a basic circuit arrangement,
  • FIG. 3 shows a cylinder with an embodiment of a control device,
  • Figure 4 shows a cylinder with a further embodiment of a control device.

Bei der dargestellten Ausbildung befindet sich auf einer Trägerplattform 1 ein Arbeitsgerät 2, das um einen Drehpunkt 3 mit einem Schwenkbereich 4 von der einen Endlage in eine Endlage 2' verstellbar ist. Der Schwenkbereich 4 umfaßt nur einen Teil des Vollkreises, weil beispielsweise der Bedienplatz 5 aus Sicht- und Bedienungsgründen über die Schwenkebene des Arbeitsgerätes 2 hinausragt.In the embodiment shown, there is a work implement 2 on a carrier platform 1, which can be adjusted about a pivot point 3 with a swivel range 4 from one end position to an end position 2 '. The swivel area 4 comprises only a part of the full circle because, for example, the operator station 5 projects beyond the swivel plane of the implement 2 for reasons of visibility and operation.

Die Schwenkbewegung wird durch zwei Hydraulikzylinder 6 und 7 bewirkt. Die Zylinder 6,7 sind beispielsweise an einem gemeinsamen Stütz- und Drehbolzen 8 mit der Trägerplattform 1 verbunden. Die zugeordneten Kolbenstangen sind versetzt an den Punkten 9 und 10 des Schwenkantriebskreises 11 für das Arbeitsgerät 2 angelenkt. Durch diese Anordnung erreichen beide Zylinder 6,7 bei unterschiedlichen Schwenkwinkeln den inneren Totpunkt, bei dem die Kolben 21,22 ganz in die Zylinder 6,7 eingefahren sind, und durch winkelabhängige Umschaltung der Zylinder 6,7 ist das Überfahren des Totpunktes möglich.The pivoting movement is effected by two hydraulic cylinders 6 and 7. The cylinders 6, 7 are connected to the carrier platform 1, for example, on a common support and pivot pin 8. The associated piston rods are offset at points 9 and 10 of the swivel drive circuit 11 for the implement 2. With this arrangement, both cylinders 6, 7 reach the inner dead center at different pivoting angles, at which the pistons 21, 22 are completely retracted into the cylinders 6, 7, and by changing the cylinders 6, 7 depending on the angle, the dead center can be passed.

Beim Anfahren der Endlagen des Arbeitsgerätes hat der jeweils nachlaufende Zylinder (6 in der Endlage 2, 7' in der Endlage 2') den größten wirksamen Hebelarm. Eine Endlagendämpfung muß also zweckmäßigerweise an diesen Zylindern wirksam werden.When moving to the end positions of the implement, the trailing cylinder (6 in the end position 2, 7 'in the end position 2') has the largest effective lever arm. End position damping must therefore be effective on these cylinders.

Dieses wird, wie in Fig, 2 dargestellt, dadurch erzeugt, daß die Zylinder 6 und 7 auf den den Dämpfungsdurck aufbauenden Seiten 12 und 13 mit je zwei Verbindungsleitungen 14, 15 und 16,17 versehen sind, die in Leitungen 18, 19 mUnden. Die Verbindungsleitungen 14 und 16 werden im Endbereich 20 des Kolbenweges von den Kolben 21,22 abgesperrt, so daß das Öl nur noch über die Verbindungsleitung 15, 17 mit eingebauten Drosselventilen 23, 24 entweichen kann, solange parallel dazu liegendende Rückschlagventile 25,26 nicht entsperrt sind.As shown in FIG. 2, this is produced in that the cylinders 6 and 7 are provided on the sides 12 and 13 building the damping pressure with two connecting lines 14, 15 and 16, 17 each, which end in lines 18, 19. The connecting lines 14 and 16 are shut off in the end region 20 of the piston path by the pistons 21, 22, so that the oil can only escape via the connecting line 15, 17 with built-in throttle valves 23, 24, as long as check valves 25, 26 lying in parallel to them do not unlock are.

Im dargestellten Fall, gemäß Fig. 1, besitzt der vorlaufende Zylinder 7 einen ungünstig kleinen wirksamen Hebelarm, so daß hier die Drosselwirkung möglichst aufgehoben werden soll.In the illustrated case, as shown in FIG. 1, the leading cylinder 7 has an unfavorably small effective lever arm, so that the throttling effect should be eliminated as far as possible.

Dieses wird durch Entsperren der Rückschlagventils 26 erreicht. Beide Kolben 21,22 laufen weiter, bis der Kolben 21 des nachlaufenden Zylinders 6 die Verbindungsleitung 14 abdeckt. Nun kann das Öl nur über die Drossel 23 entweichen, weil das Rückschlagventil 25 geschlossen bleibt, und die Endlagendämpfung ist wirksam.This is achieved by unlocking the check valve 26. Both pistons 21, 22 continue to run until the piston 21 of the trailing cylinder 6 covers the connecting line 14. Now the oil can only escape through the throttle 23 because the check valve 25 remains closed and the end position damping is effective.

Die Entsperrung der Rückschlagventile 25, 26 erfolgt zweckmäßigerweise hydraulisch über Leitungen 27, 28 und ein 4/2-Wegventil 29, das in der Ruhestellung das Rückschlagventil 26 mit einer Druckleitung 30 verbindet und entsperrt. Sensiert ein Schalter 31 über einen Nocken 32 den Wechsel des Arbeitsgerätes 2 über einen inneren Totpunkt hinaus in den Bereich der anderen Endlage 2', dann wird das Ventil 29 über einen Magneten 33 in die andere Position umgeschaltet, so daß jetzt das Rückschlagventil 25 entsperrt ist. Auf diese Weise wird erreicht, daß jeweils der Zylinder (6,7) mit dem größeren wirksamen Hebelarm, d.h. der nachlaufende Zylinder, die Endlagendämpfung ausübt. Der zu dämpfende Bereich wird durch die konstruktive Auslegung eindeutig festgelegt, so daß in dem jeweils vorlaufenden Zylinder 6 bzw. 7 keine unzulässigen Kräfte aufgebaut werden.The check valves 25, 26 are expediently unlocked hydraulically via lines 27, 28 and a 4/2-way valve 29 which, in the rest position, connects the check valve 26 to a pressure line 30 and unlocks it. If a switch 31 senses the change of the implement 2 via an internal dead center into the area of the other end position 2 'via a cam 32, then the valve 29 is switched to the other position by means of a magnet 33, so that the check valve 25 is now unlocked . In this way it is achieved that the cylinder (6,7) with the larger effective lever arm, i.e. the trailing cylinder, which applies end position damping. The area to be damped is clearly defined by the design, so that no unacceptable forces are built up in the respective leading cylinder 6 or 7.

Die Anordnung hat den Vorteil, daß selbst bei Ausfall der Druckölversorgung 30 für den Entsperrvorgang oder bei Versagen der Umschaltung an Ventil 29 die Endlagendämpfung in ausreichendem Maße wirksam bleibt.The arrangement has the advantage that even if the pressure oil supply 30 fails for the unlocking process or if the switchover at valve 29 fails, the end position damping remains sufficiently effective.

Gemäß Fig. 3 ist ein Hydraulikzylinder 34 mit beiden Verbindungsleitungen 35,36 dargestellt, bei dem die freie Verbindungsleitung 35 nicht durch den Hydraulikkolben 37 selbst, sondern über ein mit einer Feder 38 an dem Kolben befestigten und vorgeschalteten Sperrelement 39 gesteuert wird. Hierbei taucht das Sperrelement 39 in einen entsprechenden Ringraum 40 ein. Das weitere Ausfahren des Kolbens 37 ist damit nur über die Dämpfungsdrossel 41 oder das entsperrte Rückschlagventil 42 möglich.3 shows a hydraulic cylinder 34 with two connecting lines 35, 36, in which the free connecting line 35 is not through the hydraulic system piston 37 itself, but is controlled via a spring element 38 attached to the piston and connected upstream blocking element 39. Here, the blocking element 39 is immersed in a corresponding annular space 40. The further extension of the piston 37 is therefore only possible via the damping throttle 41 or the unlocked check valve 42.

Diese Ausbildung erlaubt eine freizügige konstruktive Auslegung des gedämpften Kolbenweges, ohne daß der Kolben entsprechend lang ausgeführt werden muß.This training allows a revealing constructive design of the damped piston path without the piston must be made long.

Bei einer weiteren Ausführungsform gemäß Fig. 4 ist vorgesehen, daß ein Zylinder 43 auf der Dämpfungsseite eine zusätzliche Dämpfungskammer 44 besitzt, in die im Bereich der Endlage ein Zusatzkolben 45 mit geringem Spiel eintaucht.In a further embodiment according to FIG. 4, it is provided that a cylinder 43 has an additional damping chamber 44 on the damping side, into which an additional piston 45 is immersed with little play in the region of the end position.

Dadurch wird eine angeordnete Verbindungsleitung 46 in Abhängigkeit von der Stellung des Kolbens 47 und des Zusatzkolbens 45 für einen Teil der Kolbenfläche, nämlich die Fläche des Zusatzkolbens 45, nur noch teilweise wirksam, bei sehr kleinem Spalt zwischen Zusatzkolben 45 und Dämpfungskammer 44 praktisch unwirksam. Die Dämpfungswirkung wird in diesem Fall durch das in der zusätzlichen Verbindungsleitung 48 angebrachte Drosselventil 49 aufgebracht, wobei das Drosselventil 49 verstellbar sein kann. Dem Drosselventil 49 ist ein entsperrbares Rückschlagventil 50 parallelgeschaltet, welches es erlaubt, die Drosselwirkung, beispielsweise in Abhängigkeit von der Zylinderfunktion aufzuheben.As a result, an arranged connecting line 46 is only partially effective depending on the position of the piston 47 and the additional piston 45 for part of the piston surface, namely the surface of the additional piston 45, with a very small gap between the additional piston 45 and the damping chamber 44 being virtually ineffective. In this case, the damping effect is applied by the throttle valve 49 mounted in the additional connecting line 48, wherein the throttle valve 49 can be adjustable. An unblockable check valve 50 is connected in parallel with the throttle valve 49, which allows the throttling effect to be canceled, for example as a function of the cylinder function.

Eine weitere Dämpfungsmöglichkeit ergibt sich durch Einbau eines zusätzlichpn Rückschlagventils 51 in die Verbindungsleitung 46. In diesem Fall wird auch das von Kolben 47 verdrängte Öl durch den Spalt zwischen Zusatzkolben 45 und Drosselkammer 44 gepreßt und passiert zusätzlich die einstellbare Drossel 50. Das Rückschlagventil 51 läßt sich ebenso wie das Ventil 50 in Abhängigkeit von der Zylinderfunktion entsperren. Es ist beispielsweise möglich, die Dämpfungswirkung des nachlaufenden Zylinders durch zusätzliche Entsperrung eines der beiden Rückschlagventile (50,51) zu verändern.Another damping option is provided by installing an additional p n check valve 51 in the connecting line 46. In this case, the oil displaced by piston 47 is also pressed and passed through the gap between additional piston 45 and throttle chamber 44 additionally, the adjustable throttle 50. The check valve 51 can be unlocked just like the valve 50 depending on the cylinder function. For example, it is possible to change the damping effect of the trailing cylinder by additionally unlocking one of the two check valves (50, 51).

Claims (6)

1. Einrichtung zur Endlagendämpfung für über hydraulische Zylinder betriebene Schwenkwerke von Arbeitsgeräten, wie Kräne und Baggerarme, bei denen zwei Zylinder an gegeneinander versetzten Positionen eines Schwenkantriebskreises angreifen, dadurch gekennzeichnet, daß die zu dämpfende Seite (12,13) des Zylinders (6,7) in seinem Endbereich eine Verbindungsleitung (14,16;35;46) des Hydrauliksystems und eine weitere Verbindungsleitung (15,17;36;48) mit einem Drosselventil (23,24;41;49) aufweist, wobei parallel zum Drosselventil (23,24;41;49) ein den Abfluß aus dem Zylinder (6,7;34;43) sperrendes Rückschlagventil (25,26;42;50) angeordnet ist.1. Device for end position damping for swing mechanisms operated by hydraulic cylinders of work equipment, such as cranes and excavator arms, in which two cylinders act at mutually offset positions of a swing drive circuit, characterized in that the side to be damped (12, 13) of the cylinder (6, 7 ) has in its end region a connecting line (14, 16; 35; 46) of the hydraulic system and a further connecting line (15, 17; 36; 48) with a throttle valve (23, 24; 41; 49), parallel to the throttle valve (23 , 24; 41; 49) a check valve (25, 26; 42; 50) blocking the outflow from the cylinder (6,7; 34; 43) is arranged. 2. Einrichtung nach Anspruch 1, dadurch gekennzeichnet, daß die Verbindungsleitung (14,16;35) durch den Kolben (21,22;39) verschließbar ist, während die weitere Verbindungsleitung (15,17;36) freibleibt.2. Device according to claim 1, characterized in that the connecting line (14, 16; 35) can be closed by the piston (21, 22; 39), while the further connecting line (15, 17; 36) remains free. 3. Einrichtung nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß der Kolben (37) ein über Federn (38) angeordnetes vorgeschaltetes Sperrelement (39) trägt, das mit einer stirnseitigen Steuerkammer (40) des Zylinders (34) als Abschluß zusammenwirkt und an die Steuerkammer (40) die zu verschließende Verbindungsleitung (35) angeschlossen ist.3. Device according to claim 1 or 2, characterized in that the piston (37) carries a spring (38) arranged upstream locking element (39) which cooperates with an end control chamber (40) of the cylinder (34) as a conclusion and at the control chamber (40) the connecting line (35) to be closed is connected. 4. Einrichtung nach Anspruch 1, dadurch gekennzeichnet, daß die zu dämpfende Seite des Zylinders (43) eine zusätzliche Dämpfungskammer (44) als Verlängerung aufweist, der ein am Kolben (47) angeordneter Zusatzkolben (45) kleineren Durchmessers unter Bildung eines Spaltes im Durchtrittsbereich zugeordnet ist, wobei die Verbindungsleitung (46) des Hydrauliksystems ein entsperrbares Rückschlagventil (51) aufweist während die weitere Verbindungsleitung (48) an der zusätzlichen Dämpfungskammer (44) angeschlossen ist.4. Device according to claim 1, characterized in that the side to be damped of the cylinder (43) has an additional damping chamber (44) as an extension, which is arranged on the piston (47) arranged additional piston (45) of smaller diameter with formation of a gap in the passage area is assigned, the connecting line (46) of the hydraulic system having an unlockable check valve (51) while the further connecting line (48) is connected to the additional damping chamber (44). 5. Einrichtung nach Anspruch 4, dadurch gekennzeichnet, daß der Spalt zwischen Zusatzkolben (46) und Dämpfungskammer (44) mit Annäherung an die Endlage durch die Dimensionierung des Zusatzkolbens (46) oder der Dämpfungskammer (44) abnimmt.5. Device according to claim 4, characterized in that the gap between the additional piston (46) and the damping chamber (44) decreases with approach to the end position by the dimensioning of the additional piston (46) or the damping chamber (44). 6. Einrichtung nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß die Rückschlagventile (25,26;42; 50,51) in Abhängigkeit der Totpunktlage der Zylinder (6,7) über einen Steuernocken-(32) am Schwenkantriebskreis (11) durch Steuerelemente (29,31,33) in der Weise entsperrbar sind, daß jeweils das Rückschlagventil für den Zylinder (6 bzw. 7) mit dem größeren wirksamen Hebelarm - nachlaufender Zylinder - gesperrt bleibt.6. Device according to one of claims 1 to 5, characterized in that the check valves (25,26; 42; 50,51) depending on the dead center position of the cylinder (6,7) via a control cam (32) on the swivel drive circuit (11th ) can be unlocked by controls (29,31,33) in such a way that the check valve for the cylinder (6 or 7) with the larger effective lever arm - trailing cylinder - remains blocked.
EP85102590A 1984-03-08 1985-03-07 End-of-stroke cushioning device Expired EP0157213B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3408421 1984-03-08
DE3408421A DE3408421A1 (en) 1984-03-08 1984-03-08 DEVICE DAMPING DEVICE

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EP0157213A1 true EP0157213A1 (en) 1985-10-09
EP0157213B1 EP0157213B1 (en) 1986-11-20

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EP85102590A Expired EP0157213B1 (en) 1984-03-08 1985-03-07 End-of-stroke cushioning device

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Cited By (1)

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WO1987004202A1 (en) * 1986-01-08 1987-07-16 J.C. Bamford Excavators Limited Converting linear movement to rotational movement

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NL1018501C2 (en) * 2001-07-09 2003-01-10 Actuant Corp Hydraulic control device.

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US4138928A (en) * 1977-02-11 1979-02-13 Ware Machine Service Inc. Fluid actuated apparatus
DE3137345A1 (en) * 1981-09-19 1983-04-14 Pfaff Industriemaschinen Gmbh, 6750 Kaiserslautern COMPRESSED AIR CYLINDER WITH LIMIT DAMPING
WO1983003089A1 (en) * 1982-03-08 1983-09-15 Reeves, Jerry, L. Speed reducing mast tilt indicator

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US2303976A (en) * 1939-01-31 1942-12-01 Dunlop Rubber Co Guideway or passage for machinegun ammunition belts
DE2254495A1 (en) * 1972-11-07 1974-05-22 Zettelmeyer Fa Hubert DEVICE FOR DAMPING THE STRIKING OF EACH OTHER MOVING PARTS COUPLED BY HYDRAULIC CYLINDERS
US4138928A (en) * 1977-02-11 1979-02-13 Ware Machine Service Inc. Fluid actuated apparatus
DE3137345A1 (en) * 1981-09-19 1983-04-14 Pfaff Industriemaschinen Gmbh, 6750 Kaiserslautern COMPRESSED AIR CYLINDER WITH LIMIT DAMPING
WO1983003089A1 (en) * 1982-03-08 1983-09-15 Reeves, Jerry, L. Speed reducing mast tilt indicator

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WO1987004202A1 (en) * 1986-01-08 1987-07-16 J.C. Bamford Excavators Limited Converting linear movement to rotational movement

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DE3560023D1 (en) 1987-01-08
EP0157213B1 (en) 1986-11-20
DE3408421A1 (en) 1985-09-12

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