EP0055247B1 - Loading crane - Google Patents

Loading crane Download PDF

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Publication number
EP0055247B1
EP0055247B1 EP81890209A EP81890209A EP0055247B1 EP 0055247 B1 EP0055247 B1 EP 0055247B1 EP 81890209 A EP81890209 A EP 81890209A EP 81890209 A EP81890209 A EP 81890209A EP 0055247 B1 EP0055247 B1 EP 0055247B1
Authority
EP
European Patent Office
Prior art keywords
hydraulic drive
swivel arm
valve
cylinder space
conduit
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
Application number
EP81890209A
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German (de)
French (fr)
Other versions
EP0055247A3 (en
EP0055247A2 (en
Inventor
Georg Popodi
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.)
Palfinger AG
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Palfinger AG
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Filing date
Publication date
Application filed by Palfinger AG filed Critical Palfinger AG
Publication of EP0055247A2 publication Critical patent/EP0055247A2/en
Publication of EP0055247A3 publication Critical patent/EP0055247A3/en
Application granted granted Critical
Publication of EP0055247B1 publication Critical patent/EP0055247B1/en
Expired legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/003—Systems with load-holding valves
    • 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
    • B66C23/88—Safety gear
    • B66C23/90—Devices for indicating or limiting lifting moment
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/50—Pressure control
    • F15B2211/505—Pressure control characterised by the type of pressure control means
    • F15B2211/50509—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
    • F15B2211/50545—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using braking valves to maintain a back pressure

Definitions

  • the invention relates to a loading crane with a swivel arm which can be raised and lowered by means of a first hydraulic drive and which optionally comprises a plurality of swivel arm parts which can be moved relative to one another by means of further hydraulic drives, a load holding valve being connected upstream of the cylinder space of the first hydraulic drive associated with a lifting movement of the swivel arm which can be controlled into the open position by an increase in pressure in the line connected to the cylinder chamber associated with a lowering movement, and with which an overload valve communicates with the first hydraulic drive, which at least blocks the first hydraulic drive against a movement which increases the load torque in the event of a crane overload.
  • the invention was accordingly based on the object of preventing the overload valve from responding in the simplest manner if the pressure in the lowering line is increased in order to open the load holding valve and thus to enable the lowering movement.
  • this is achieved either by a spring-loaded compensation valve with two oppositely acting control pistons, which responds to a differential pressure corresponding to the load torque, or by a pressure reducing valve built into the lowering line, which keeps the excess pressure away from the drive cylinder of the swivel arm.
  • FIG. 1 shows the diagram of a loading crane according to the invention with a compensation of the pressure increase in the overload valve required for the lowering movement of the swivel arm
  • Fig. 2 shows the compensation by a compensation valve upstream of the overload valve
  • Fig. 3 shows the use of a pressure reducing valve for this purpose .
  • the swivel arm 2 is shown of the well-known loading crane 1, which can be raised or lowered by means of a hydraulic drive 3 consisting of cylinder and piston with piston rod. It is easy to see that the load torque is reduced or increased by this lifting or lowering movement.
  • the cylinder space 3 ′′ of the hydraulic drive 3 assigned to the lowering movement is connected to a control valve 4 via a lowering line 7.
  • a known load-holding valve 12 is connected upstream of the cylinder space 3 ′ assigned to a lifting movement of the swivel arm 2 and is likewise connected to the control valve 4 via a line 6
  • the cylinder chamber 3 communicates with an overload valve 11 via a line 8.
  • This overload valve is biased into the closed position by means of a spring and has a first control piston which counteracts the spring force and communicates with the line 8 via a line 10.
  • a second control piston whose direction of action is opposite to the first control piston, communicates with the lowering line 7 via a line 13.
  • the overload valve 11 responds in a known manner; H. it connects the line 8 to the line 16 and thus actuates a locking drive 5.
  • This locking drive 5 shifts all control valves 4 into a neutral position, which are assigned hydraulic drives which can cause a movement which increases the load moment.
  • the locking drive 5 can either be integrated into the control valves in a known manner, but it can also act directly on the hand lever for actuating the control valves.
  • the overload valve 11 blocks the control valve 4 via the blocking drive 5 in the manner previously described.
  • the overload valve 11 is a Pressure compensation valve 14 connected upstream, which in turn has two counteracting control pistons and is resiliently biased into the closed position.
  • the first control piston communicates with the cylinder space 3 ′ of the drive 3 via a line 10
  • the second control piston communicates with the lower line 7 via a line 13.
  • FIG. 3 Another possibility of pressure compensation when lowering the swivel arm 2 is shown in FIG. 3.
  • a pressure reducing valve 15 is switched into the lowering line 7 between the connection for the control line 9 of the load holding valve 12 and the hydraulic drive 3.
  • This pressure reducing valve 15 prevents the overpressure required for the lowering control of the load holding valve from propagating in the lowering line 7 into the cylinder space 3 ′′ and thus superimposed on the pressure resulting from the load moment.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • General Engineering & Computer Science (AREA)
  • Jib Cranes (AREA)
  • Fluid-Pressure Circuits (AREA)

Description

Die Erfindung betrifft einen Ladekran mit einem mittels eines ersten, hydraulischen Antriebs heb- und senkbaren Schwenkarm, der gegebenenfalls aus mehreren, mittels weiteren, hydraulischen Antrieben gegeneinander bewegbaren Schwenkarmteilen besteht, wobei dem einer Hebbewegung des Schwenkarmes zugeordneten Zylinderraum des ersten, hydraulischen Antriebs ein Lasthalteventil vorgeschaltet ist, welches durch Druckanstieg in der mit dem einer Senkbewegung zugeordneten Zylinderraum verbundenen Leitung in die Offenstellung steuerbar ist, und wobei mit dem ersten, hydraulischen Antrieb ein Überlastventil kommuniziert, welches bei einer Kranüberlastung zumindestens den ersten hydraulischen Antrieb gegen eine das Lastmoment vergroßernde Bewegung sperrt.The invention relates to a loading crane with a swivel arm which can be raised and lowered by means of a first hydraulic drive and which optionally comprises a plurality of swivel arm parts which can be moved relative to one another by means of further hydraulic drives, a load holding valve being connected upstream of the cylinder space of the first hydraulic drive associated with a lifting movement of the swivel arm which can be controlled into the open position by an increase in pressure in the line connected to the cylinder chamber associated with a lowering movement, and with which an overload valve communicates with the first hydraulic drive, which at least blocks the first hydraulic drive against a movement which increases the load torque in the event of a crane overload.

In der Zeitschrift "Ölhydraulik und Pneumatik",- Band 21, Nr. 6, Juni 1977, ist auf den Seiten 458 - 460 eine Steuerung hydraulischer Hebezeuge beschrieben. Die Fig. 3 zeigt Antriebe, welche sowohl eine Überlastsicherung als auch ein Lasthalteventil enthalten. Nachteilig dabei ist, daß komplizierte Zusatzeinrichtungen wie 2/2-Wege-Magnetventile, Hilfssteuerkanale und zusätzliche Anzapfungen an den Ventilen erforderlich sind, um bei Ansprechen der Überlastsicherungen eine Bewegung in die das Lastmoment verkleinernde Richtung zu ermöglichen.In the journal "Oil hydraulics and pneumatics.", - a controlling hydraulic hoists 460. - Volume 21, No. 6, June 1977 is on pages 458th 3 shows drives which contain both an overload protection and a load holding valve. The disadvantage here is that complicated additional devices such as 2/2-way solenoid valves, auxiliary control channels and additional taps on the valves are required to enable movement in the direction reducing the load torque when the overload safety devices respond.

Der Erfindung lag demgemäß die Aufgabe zugrunde, auf einfachste Weise das Ansprechen des Überlastventiles zu verhindern, wenn der Druck in der Senkleitung erhöht wird, um das Lasthalteventil zu öffnen und damit die Senkbewegung zu ermöglichen.The invention was accordingly based on the object of preventing the overload valve from responding in the simplest manner if the pressure in the lowering line is increased in order to open the load holding valve and thus to enable the lowering movement.

Erfindungsgemäß wird dies entweder durch ein federbelastetes Kompensationsventil mit zwei entgegengesetzt wirkenden Steuerkolben erreicht, welches auf einen dem Lastmoment entsprechenden Differenzdruck anspricht, oder aber durch ein in die Senkleitung eingebautes Druckreduzierventil, welches den Überdruck vom Antriebszylinder des Schwenkarmes fernhält.According to the invention, this is achieved either by a spring-loaded compensation valve with two oppositely acting control pistons, which responds to a differential pressure corresponding to the load torque, or by a pressure reducing valve built into the lowering line, which keeps the excess pressure away from the drive cylinder of the swivel arm.

Bei beiden Konstruktionen bleibt die Sicherheit gegen Überlastung auch beim Senken voll erhalten.In both constructions, the safety against overloading is fully retained even when lowering.

Weitere Einzelheiten der Erfindung werden nachfolgend an Hand einer Reihe von Ausführungsbeispielen und unter Bezugnahme auf die Zeichnungsfiguren näher erläutert. >ebei zeigen die Fig. 1 das Schema eines erfindungsgemäßen Ladekrans mit einer Kompensation des für die Senkbewegung des Schwenkarmes erforderlichen Druckanstiegs im Überlastventil, die Fig. 2 die Kompensation durch ein dem Überlastventil vorgeschaltetes Kompensationsventil und die Fig. 3 die Verwendung eines Druckreduzierventils für diesen Zweck.Further details of the invention are explained in more detail below using a number of exemplary embodiments and with reference to the drawing figures. > Fig. 1 shows the diagram of a loading crane according to the invention with a compensation of the pressure increase in the overload valve required for the lowering movement of the swivel arm, Fig. 2 shows the compensation by a compensation valve upstream of the overload valve and Fig. 3 shows the use of a pressure reducing valve for this purpose .

Bei dem in der Fig. 1 dargestellten Ausführungsbeispiel ist von dem hinreichend bekannten Ladekran 1 nur der Schwenkarm 2 dargestellt, welcher mittels eines aus Zylinder und Kolben mit Kolbenstange bestehenden hydraulischen Antriebs 3 angehoben bzw. abgesenkt werden kann. Es ist leicht ersichtlich, daß durch diese Heb- bzw. Senkbewegung das Lastmoment verkleinert bzw. vergrößert wird. Der der Senkbewegung zugeordnete Zylinderraum 3" des hydraulischen Antriebs 3 ist über eine Senkleitung 7 mit einem Steuerventil 4 verbunden. Dem einer Hebbewegung des Schwenkarmes 2 zugeordneten Zylinderraum 3' ist ein bekanntes Lasthalteventil 12 vorgeschaltet, welches ebenfalls über eine Leitung 6 mit dem Steuerventil 4 verbunden ist. Weiters kommuniziert der Zylinderraum 3' über eine Leitung 8 mit einem Überlastventil 11. Dieses Überlastventil ist in die Geschlossenstellung mittels einer Feder vorgespannt, und weist einen ersten, der Federkraft entgegenwirkenden Steuerkolben auf, welcher über eine Leitung 10 mit der Leitung 8 kommuniziert. Ein zweiter Steuerkolben, dessen Wirkungsrichtung dem ersten Steuerkolben entgegengesetzt ist, kommuniziert über eine Leitung 13 mit der Senkleitung 7.In the embodiment shown in FIG. 1, only the swivel arm 2 is shown of the well-known loading crane 1, which can be raised or lowered by means of a hydraulic drive 3 consisting of cylinder and piston with piston rod. It is easy to see that the load torque is reduced or increased by this lifting or lowering movement. The cylinder space 3 ″ of the hydraulic drive 3 assigned to the lowering movement is connected to a control valve 4 via a lowering line 7. A known load-holding valve 12 is connected upstream of the cylinder space 3 ′ assigned to a lifting movement of the swivel arm 2 and is likewise connected to the control valve 4 via a line 6 Furthermore, the cylinder chamber 3 'communicates with an overload valve 11 via a line 8. This overload valve is biased into the closed position by means of a spring and has a first control piston which counteracts the spring force and communicates with the line 8 via a line 10. A second control piston, whose direction of action is opposite to the first control piston, communicates with the lowering line 7 via a line 13.

Wird nun der Ladekran beispielsweise durch ein zu weites Ausfahren eines nicht dargestellten Verlängerungsarmes überlastet, so spricht das Überlastventil 11 in bekannter Weise an, d. h. es verbindet die Leitung 8 mit der Leitung 16 und betätigt so einen Sperrantrieb 5. Dieser Sperrantrieb 5 verschiebt alle Steuerventile 4 in eine neutrale Stellung, welche hydraulischen Antrieben zugeordnet sind, die eine das Lastmoment vergrößernde Bewegung bewirken können. Der Sperrantrieb 5 kann entweder in bekannter Weise in die Steuerventile integriert sein, er kann aber auch direkt auf die Handhebel zur Betätigung der Steuerventile wirken.If the loading crane is now overloaded, for example by an extension arm (not shown) being extended too far, the overload valve 11 responds in a known manner; H. it connects the line 8 to the line 16 and thus actuates a locking drive 5. This locking drive 5 shifts all control valves 4 into a neutral position, which are assigned hydraulic drives which can cause a movement which increases the load moment. The locking drive 5 can either be integrated into the control valves in a known manner, but it can also act directly on the hand lever for actuating the control valves.

Bei dem Schwenken des Schwenkarmes mittels des hydraulischen Antriebes 3 muß aufgrund des Lasthalteventils 12 in bekannter Weise in der Senkleitung 7 ein Überdruck aufgebaut werden, sodaß das Lasthalteventil 12 über die Leitung 9 in die Offenstellung gesteuert werden kann. Dieser Überdruck in der Leitung 7 und dem Zylinderraum 3" pflanzt sich auch in den Zylinderraum 3' fort und überlagert sich dort dem vom Lastmoment herrührenden Druck. Zugleich wird jedoch dieser Druckanstieg im Überlastventil 11 dadurch kompensiert, daß dem ersten, über die Leitung 10 mit dem Zylinderraum 3' kommunizierenden Steuerkolben ein zweiter Steuerkolben entgegenwirkt, der über die Leitung 13 mit der Senkleitung 7 kommuniziert. Damit bleibt die Schaltschwelle des Überlastventils konstant.When pivoting the swivel arm by means of the hydraulic drive 3, an excess pressure must be built up in the lowering line 7 in a known manner due to the load holding valve 12, so that the load holding valve 12 can be controlled via the line 9 into the open position. This overpressure in the line 7 and the cylinder space 3 "also propagates into the cylinder space 3 'and is superimposed there on the pressure resulting from the load moment. At the same time, however, this pressure increase in the overload valve 11 is compensated for by the fact that the first one, via the line 10 counteracts the control piston communicating with the cylinder chamber 3 ', a second control piston communicating with the lowering line 7 via the line 13. The switching threshold of the overload valve thus remains constant.

Tritt jedoch während des Absenkens des Schwenkarmes 2 eine tatsächliche Überlastung ein, so blockiert das Überlastventil 11 über den Sperrantrieb 5 in der vorher beschriebenen Weise das Steuerventil 4.However, if an actual overload occurs during the lowering of the swivel arm 2, the overload valve 11 blocks the control valve 4 via the blocking drive 5 in the manner previously described.

Bei der in der Fig. 2 dargestellten Variante ist dem Überlastventil 11 ein Druckkompensationsventil 14 vorgeschaltet, welches wiederum zwei entgegenwirkende Steuerkolben aufweist und federnd in die Geschlossenstellung vorgespannt ist. Auch hier kommuniziert der erste Steuerkolben über eine Leitung 10 mit dem Zylinderraum 3' des Antriebs 3, während der zweite Steuerkolben über eine Leitung 13 mit der Senkleitung 7 kommuniziert.In the variant shown in FIG. 2, the overload valve 11 is a Pressure compensation valve 14 connected upstream, which in turn has two counteracting control pistons and is resiliently biased into the closed position. Here, too, the first control piston communicates with the cylinder space 3 ′ of the drive 3 via a line 10, while the second control piston communicates with the lower line 7 via a line 13.

Eine weitere Möglichkeit der Druckkompensation beim Absenken des Schwenkarmes 2 ist in der Fig. 3 dargestellt. Hier ist zwischen dem Anschluß für die Steuerleitung 9 des Lasthalteventils 12 und dem hydraulischen Antrieb 3 ein Druckreduzierventil 15 in die Senkleitung 7 eingeschaltet. Dieses Druckreduzierventil 15 verhindert, daß sich der für die Senksteuerung des Lasthalteventils erforderliche Überdruck in der Senkleitung 7 bis in den Zylinderraum 3" fortpflanzt und somit dem vom Lastmoment herrührenden Druck überlagert.Another possibility of pressure compensation when lowering the swivel arm 2 is shown in FIG. 3. Here, a pressure reducing valve 15 is switched into the lowering line 7 between the connection for the control line 9 of the load holding valve 12 and the hydraulic drive 3. This pressure reducing valve 15 prevents the overpressure required for the lowering control of the load holding valve from propagating in the lowering line 7 into the cylinder space 3 ″ and thus superimposed on the pressure resulting from the load moment.

Claims (4)

1. Loading crane with a swivel arm liftable and lowerable by means of a first hydraulic drive and comprising, if required, a number of further swivel arm elements movable towards one another by means of further hydraulic drives, ahead of the cylinder space (3') of the first hydraulic drive (3) which is associated with an upward motion of the swivel arm (2), a load holding valve (12) being arranged and movable into the open position by pressure increase in the conduit (7) connected with the cylinder space associated with a lowering motion, and an overload valve (11) communicating with the first hydraulic drive and blocking at least the first hydraulic drive against a motion increasing the load moment, when the crane is overloaded, characterized by a spring-loaded compensating valve with two oppositely acting control pistons, the first of said pistons - as known per se - counteracting the spring force and communicating via a first conduit (10) with a cylinder space (3') of the first hydraulic drive (3) associated with a lifting motion of the swivel arm (2), and the second of said pistons, whose direction of action is opposed to the first control piston, being connected with the lowering conduit (7) of the first hydraulic drive (3) via a second conduit (13).
2. Loading crane according to claim 1, characterized in that the compensating valve is integrated into the overload valve (11) in that the latter-mentioned has an additional control piston connected with the second conduit (13), (Fig. 1)
3. Loading crane according to claim 1, characterized in that the compensating valve (14) is mounted into the connecting conduit (8) between the cylinder space (3') associated with a lifting motion of the swivel arm (2) and the overload valve (11), (Fig. 2).
4. Loading crane with a swivel arm liftable and lowerable by means of a first hydraulic drive and comprising, if required, a number of further swivel arm elements movable towards one another by means of further hydraulic drives, ahead of the cylinder space (3') of the first hydraulic drive (3) which is associated with an upward motion of the swivel arm (2), a load holding valve (12) being arranged and movable into the open position by pressure increase in the conduit (7) connected with the cylinder space associated with a lowering motion, and an overload valve (11) communicating with the first hydraulic drive and blocking at least the first hydraulic drive against a motion increasing the load moment, when the crane is overloaded, characterized in that a pressure reducing valve (15) is arranged in advance of the cylinder space (3") of the first hydraulic drive (1) associated with a lowering motion of the swivel arm (2).
EP81890209A 1980-12-23 1981-12-23 Loading crane Expired EP0055247B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AT0628080A AT368107B (en) 1980-12-23 1980-12-23 LOADING CRANE
AT6280/80 1980-12-23

Publications (3)

Publication Number Publication Date
EP0055247A2 EP0055247A2 (en) 1982-06-30
EP0055247A3 EP0055247A3 (en) 1984-07-25
EP0055247B1 true EP0055247B1 (en) 1986-09-03

Family

ID=3584717

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Application Number Title Priority Date Filing Date
EP81890209A Expired EP0055247B1 (en) 1980-12-23 1981-12-23 Loading crane

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EP (1) EP0055247B1 (en)
AT (1) AT368107B (en)
DE (1) DE3175278D1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3414182A1 (en) * 1984-04-14 1985-10-24 Robert Bosch Gmbh, 7000 Stuttgart HYDRAULIC OVERLOAD PROTECTION DEVICE FOR A LIFTER
DE3414183A1 (en) * 1984-04-14 1985-10-24 Robert Bosch Gmbh, 7000 Stuttgart HYDRAULIC OVERLOAD PROTECTION DEVICE FOR A LOADING CRANE
CN106185633B (en) * 2016-08-24 2018-02-23 三一汽车起重机械有限公司 Balancing valve apparatus, crane and elevating mechanism

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE346762C (en) * 1970-11-04 1979-05-14 Hiab Foco Ab LOCK AND SAFETY DEVICE FOR HYDRAULICALLY OPERATED TRAVEL CRANES
US3841493A (en) * 1972-06-05 1974-10-15 J Becker Moment monitoring system for hydraulic-piston type cranes
US3814265A (en) * 1973-08-20 1974-06-04 Harnischfeger Corp Hydraulic crane control system having means for deactivating control valves when operating limit is exceeded
SE422315B (en) * 1980-06-04 1982-03-01 Hiab Foco Ab OVERLOAD PROTECTION FOR HYDRAULIC DRIVE CRANES

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
ÖLHYDRAULIK UND PNEUMATIC, Band 21, Nr. 6, Juni 1977, Mainz (DE) G. BEITLER: "Steuerung hydraulischer Hebezeuge", Seiten 458-460 *

Also Published As

Publication number Publication date
EP0055247A3 (en) 1984-07-25
AT368107B (en) 1982-09-10
EP0055247A2 (en) 1982-06-30
DE3175278D1 (en) 1986-10-09
ATA628080A (en) 1982-01-15

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