WO2011015442A1 - Fork carriage for a forklift - Google Patents

Fork carriage for a forklift Download PDF

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Publication number
WO2011015442A1
WO2011015442A1 PCT/EP2010/060327 EP2010060327W WO2011015442A1 WO 2011015442 A1 WO2011015442 A1 WO 2011015442A1 EP 2010060327 W EP2010060327 W EP 2010060327W WO 2011015442 A1 WO2011015442 A1 WO 2011015442A1
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WO
WIPO (PCT)
Prior art keywords
differential cylinder
volume
fork carriage
piston
piston rod
Prior art date
Application number
PCT/EP2010/060327
Other languages
German (de)
French (fr)
Inventor
Jürgen KELLER
Original Assignee
Hubtex Maschinenbau Gmbh & Co. Kg
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
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First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=43543954&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=WO2011015442(A1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Hubtex Maschinenbau Gmbh & Co. Kg filed Critical Hubtex Maschinenbau Gmbh & Co. Kg
Priority to AU2010280949A priority Critical patent/AU2010280949A1/en
Priority to RU2011101955/11A priority patent/RU2533627C2/en
Priority to EP10734979.7A priority patent/EP2451738B1/en
Priority to PL10734979T priority patent/PL2451738T3/en
Publication of WO2011015442A1 publication Critical patent/WO2011015442A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
    • B66F9/00—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
    • B66F9/06—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
    • B66F9/075—Constructional features or details
    • B66F9/12—Platforms; Forks; Other load supporting or gripping members
    • B66F9/14—Platforms; Forks; Other load supporting or gripping members laterally movable, e.g. swingable, for slewing or transverse movements
    • B66F9/142—Movements of forks either individually or relative to each other
    • B66F9/143—Movements of forks relative to each other - symmetric
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
    • B66F9/00—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
    • B66F9/06—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
    • B66F9/075—Constructional features or details
    • B66F9/20—Means for actuating or controlling masts, platforms, or forks
    • B66F9/22—Hydraulic devices or systems

Definitions

  • the invention relates to a fork carriage for a forklift, with a support frame, with at least two load receptacles, preferably tines, which are mounted transversely to the longitudinal extent displaceable on the support frame, each load receiving a hydraulically actuated differential cylinder for effecting the displacement is associated.
  • Forklift trucks are among the most widely used industrial trucks.
  • An essential element of the forklift truck is its lifting unit, which comprises a lifting mast and a fork carriage.
  • the latter comprises two load receptacles (usually tines) which are adjustable in their spacing to adapt to the size of the item to be lifted. The shift is done manually with very simple variants of the fork carriage.
  • each load receiver is associated with a hydraulically operable differential cylinder for effecting dislocation.
  • the differential cylinders are acted upon in parallel with the hydraulic medium.
  • the supplied stream of hydraulic medium - usually hydraulic oil - using a flow divider or Chokes are divided into streams of the required size and fed to the respective differential cylinder.
  • these flow dividers already have a pitch error in the optimum range and are always tuned to a precisely defined volume flow. If this value is undershot, the division error increases. Exceeding leads to increased wear of the flow divider. Such flow divider therefore work acceptable only in a very narrow volume flow range.
  • the invention is therefore an object of the invention to provide a fork carriage for a forklift, which is characterized by improved reliability and less susceptible to wear.
  • the piston rod-side cylinder volume of a differential cylinder is connected to the piston-side volume of another differential cylinder in this fork carriage.
  • the differential cylinders are connected in other words in series. Since the piston rod-side annular surface of the one differential cylinder is in a predetermined relationship to the piston-side surface of the other differential cylinder displacements of the two pistons of the differential cylinder over lengths take place in the supply of a certain volume of hydraulic medium, which are fixed by this ratio. A deviating from this ratio or even independent displacement of each one of the differential cylinder associated load bearing is therefore excluded by principle.
  • the fork carriage according to the invention is thus characterized by a significantly improved reliability. Moreover, since a hydraulic flow divider is completely dispensed with, but the required selection of the differential cylinders used does not lead to additional manufacturing outlay, the fork carriage according to the invention is even more cost-effective to manufacture.
  • the load receptacles preferably comprise adjustable spacing, i. transversely to the longitudinal extent of displaceable tines. Usually, the tines are always displaced by the same length at a fork adjustment.
  • the piston rod-side annular surface of a differential cylinder is thus preferably chosen to be the same size as the piston-side surface of the other differential cylinder.
  • the area ratio is thus preferably 1: 1.
  • the differential cylinder preferably comprise in at least one of its end positions overflow, by means of which overflowed hydraulic medium can be returned to the respective volume ,
  • overflow devices can-particularly preferably-comprise a bypass bore in a cylinder housing whose flow resistance is large compared to that of the remaining flow through the hydraulic medium. lumina of the differential cylinder and their leads is.
  • the tines do not shift back to the zero position, in other words: for example, in the fully retracted position of the piston rod of a differential cylinder, the piston rod of the other differential cylinder is still in a deflected position, the supply of hydraulic medium in this direction of actuation, only continue to be maintained until the volume of the hydraulic medium required to reach the zero position of the second tine has been transferred via this bypass bore.
  • not only two differential cylinders can be connected in series in the manner described. This is also possible with a larger number, so that the fork carriage according to the invention can also be equipped with a larger number of tines, if this is advantageous, for example, for special applications.
  • the invention thus also relates to an industrial truck, in particular a forklift, with a fork carriage of the type described above.
  • the drawing shows an embodiment of a Gabelträ- gers invention is shown. Show it:
  • Figure 1 shows the fork carriage in a perspective view obliquely from the front.
  • FIG. 2 shows the same fork carriage obliquely in a perspective view
  • Fig. 3 is a hydraulic diagram of the fork carriage according to FIGS. 1 and 2, as well
  • Fig. 4 shows the hydraulic diagram of a conventional fork carrier.
  • the slide 2 'shown on the right in FIG. 1 and accordingly on the left in FIG. 2 is accordingly connected to the piston rod 6 of the differential cylinder 4 shown in the drawing below, whose housing 5 is connected to the support frame 7.
  • the piston rod-side annular volume 8 of the upper differential cylinder 4 ' is connected via a connecting line 9 to the piston-side volume 10 of the lower differential cylinder 4.
  • the volumes 8 and 10 and the internal volume of the connecting line 9 thus form an internal volume which is hydraulically substantially separated from the pistons 11, 11 'by an external volume.
  • the outer volume is formed by the piston-side volume 12 of the upper differential cylinder 4 ', by the piston rod-side annular volume 13 of the lower differential cylinder 4 and the volumes of hydraulic lines 14, 14', via which the volume 12 and the annular volume 13 to a hydraulic pressure source 15th are connected.
  • the differential cylinders 4, 4 ' are each equipped with an overflow device 16, 16', via which, in the end positions of the pistons 11, 11 'of the differential cylinders shown in FIG. 3, hydraulic fluid is supplied from the piston-side volumes 10, 12 into the piston rod side Ring volumes 8, 13 can flow over.
  • the overflow devices may comprise the overflow selectively releasing valve means. However, they can also be designed as bypass lines 17, 17 ', which have a considerably higher flow resistance than the other hydraulic volumes.
  • the annular surface 18 of the piston rod side of the differential cylinder 4 is selected to be the same size as the surface 19 of the piston side of the differential cylinder 4.
  • Fig. 4 shows the hydraulic diagram of a conventional fork carrier, is obvious, this is not ensured in the parallel control of the differential cylinder. Because here the respective displacement depends on how the volume flow of the hydraulic medium is distributed over a length divider 20.

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  • Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Structural Engineering (AREA)
  • Civil Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Forklifts And Lifting Vehicles (AREA)

Abstract

In a fork carriage (100) for a forklift, having a support frame (7), having at least two load bearing members (1) that are movably mounted on the support frame (7) so that their distance apart is alterable, wherein a hydraulically operable differential cylinder (4, 4’) for effecting the movement is associated with each load bearing member (1), the piston rod-side annular volume (8) of one differential cylinder (4’) is connected to the piston-side volume (10) of the other differential cylinder (4). The piston rod–side annular area (18) of the one differential cylinder (4’) is in a predetermined ratio to the piston-side area (19) of the other differential cylinder (4).

Description

Gabelträger für einen Gabelstapler  Fork carrier for a forklift
Die Erfindung betrifft einen Gabelträger für einen Gabelstapler, mit einem Traggestell, mit mindestens zwei Lastaufnahmen, vorzugsweise Zinken, die quer zu deren Längserstreckung verlagerbar an dem Traggestell gelagert sind, wobei jeder Lastaufnahme ein hydraulisch betätigbarer Differentialzylinder zum Bewirken der Verlagerung zugeordnet ist. The invention relates to a fork carriage for a forklift, with a support frame, with at least two load receptacles, preferably tines, which are mounted transversely to the longitudinal extent displaceable on the support frame, each load receiving a hydraulically actuated differential cylinder for effecting the displacement is associated.
Gabelstapler gehören zu den am weitesten verbreiteten Flurförderzeugen. Wesentliches Element der Gabelstapler ist seine Hubeinheit, welche einen Hubmast und einen Gabelträger umfasst. Letzterer umfasst zwei zur Anpassung an die Größe des zu hebenden Guts in ihrem Abstand verstellbare Lastaufnahmen (meist Zinken). Die Verlagerung erfolgt bei sehr einfachen Varianten des Gabelträgers manuell. Bei Gabelträgern von modernen Gabelstaplern ist jedoch jeder Lastaufnahme ein hydraulisch betätigbarer Differentialzylinder zum Bewirken der Verlage- rung zugeordnet. Forklift trucks are among the most widely used industrial trucks. An essential element of the forklift truck is its lifting unit, which comprises a lifting mast and a fork carriage. The latter comprises two load receptacles (usually tines) which are adjustable in their spacing to adapt to the size of the item to be lifted. The shift is done manually with very simple variants of the fork carriage. In fork carriers of modern forklift trucks, however, each load receiver is associated with a hydraulically operable differential cylinder for effecting dislocation.
Da die Verlagerung der Lastaufnahmen in den allermeisten Fällen in Abhängigkeit voneinander erfolgen muss, um beispielsweise sicherzustellen, dass das zu hebende Gut stets mittig angehoben wird, werden die Differentialzylinder parallel mit dem Hydraulikmedium beaufschlagt. Hierzu wird der zugeführte Strom des Hydraulikmediums - üblicherweise Hydrauliköl - mit Hilfe eines Mengenteilers oder Drosseln in Ströme der benötigten Größe aufgeteilt und dem jeweiligen Differenti- alzylinder zugeführt. Diese Mengenteiler haben erfahrungsgemäß bereits im optimalen Bereich einen Teilungsfehler und sind stets auf einen genau definierten Volumenstrom abgestimmt. Wird dieser unterschritten, erhöht sich der Teilungsfeh- ler. Eine Überschreitung führt zu einem erhöhten Verschleiß des Mengenteilers. Derartige Mengenteiler arbeiten daher nur in einem sehr schmalen Volumenstrombereich akzeptabel. Since the shift of the load pickups must be done in most cases in dependence on each other, for example, to ensure that the material to be lifted is always raised in the middle, the differential cylinders are acted upon in parallel with the hydraulic medium. For this purpose, the supplied stream of hydraulic medium - usually hydraulic oil - using a flow divider or Chokes are divided into streams of the required size and fed to the respective differential cylinder. Experience has shown that these flow dividers already have a pitch error in the optimum range and are always tuned to a precisely defined volume flow. If this value is undershot, the division error increases. Exceeding leads to increased wear of the flow divider. Such flow divider therefore work acceptable only in a very narrow volume flow range.
Bei der Konstruktion von Gabelträgern besteht nun das Problem, dass die VoIu- menströme des Fahrzeugs, für das der Gabelträger vorgesehen ist, entweder nicht ausreichend genau bekannt sind oder auch sehr stark variieren. Darüber hinaus kann es durch Toleranzen, schlechte Wartung oder Beschädigungen vorkommen, dass eine Lastaufnahme zur Verstellung eine größere Kraft benötigt als der andere. Auch hierdurch ist eine Verlagerung der Lastaufnahmen in der ge- wünschten Abhängigkeit voneinander nicht immer gewährleistet. In the construction of fork carriers, the problem now is that the volume flows of the vehicle for which the fork carriage is intended are either not known with sufficient accuracy or vary very widely. In addition, it may be due to tolerances, poor maintenance or damage that a load pickup for adjustment requires a greater force than the other. This also does not always guarantee a shift of the load receptacles in the desired dependence on one another.
Der Erfindung liegt daher die Aufgabe zugrunde, einen Gabelträger für einen Gabelstapler zu schaffen, welcher sich durch eine verbesserte Funktionssicherheit auszeichnet und weniger verschleißanfällig ist. The invention is therefore an object of the invention to provide a fork carriage for a forklift, which is characterized by improved reliability and less susceptible to wear.
Diese Aufgabe wird durch den in Anspruch 1 wiedergegebenen Gabelträger gelöst. This object is achieved by the reproduced in claim 1 fork carriage.
Erfindungsgemäß ist bei diesem Gabelträger das kolbenstangenseitige Zylinder- volumen eines Differentialzylinders mit dem kolbenseitigen Volumen eines anderen Differentialzylinders verbunden. Die Differentialzylinder sind mit anderen Worten in Reihe geschaltet. Da sich nun die kolbenstangenseitige Ringfläche des einen Differentialzylinders in einem vorbestimmten Verhältnis zur kolbenseitigen Fläche des anderen Differentialzylinders steht, finden bei der Zufuhr eines be- stimmten Volumens an Hydraulikmedium Verlagerungen der beiden Kolben der Differentialzylinder über Längen statt, die von diesem Verhältnis fest vorgegeben sind. Eine von diesem Verhältnis abweichende oder gar voneinander unabhängige Verlagerung der jeweils einem der Differentialzylinder zugeordneten Lastaufnahme ist daher prinzipbedingt ausgeschlossen. Der erfindungsgemäße Gabelträger zeichnet sich somit durch eine erheblich verbesserte Betriebssicherheit aus. Da darüber hinaus auf einen hydraulischen Mengenteiler vollständig verzichtet wird, die erforderliche Auswahl der eingesetzten Differentialzylinder jedoch nicht zu zusätzlichem Fertigungsaufwand führt, ist der erfindungsgemäße Gabelträger dar- über hinaus sogar preisgünstiger in der Herstellung. According to the invention, the piston rod-side cylinder volume of a differential cylinder is connected to the piston-side volume of another differential cylinder in this fork carriage. The differential cylinders are connected in other words in series. Since the piston rod-side annular surface of the one differential cylinder is in a predetermined relationship to the piston-side surface of the other differential cylinder displacements of the two pistons of the differential cylinder over lengths take place in the supply of a certain volume of hydraulic medium, which are fixed by this ratio. A deviating from this ratio or even independent displacement of each one of the differential cylinder associated load bearing is therefore excluded by principle. The fork carriage according to the invention is thus characterized by a significantly improved reliability. Moreover, since a hydraulic flow divider is completely dispensed with, but the required selection of the differential cylinders used does not lead to additional manufacturing outlay, the fork carriage according to the invention is even more cost-effective to manufacture.
Die Lastaufnahmen umfassen bevorzugt in ihrem Abstand verstellbare, d.h. quer zu deren Längserstreckung verlagerbare Zinken. Üblicherweise sollen die Zinken bei einer Zinkenverstellung stets um dieselbe Länge verlagert werden. Die kolbenstangenseitige Ringfläche des einen Differen- tialzylinders ist somit vorzugsweise genauso groß gewählt wie die kolbenseitige Fläche des anderen Differentialzylinders. Das Flächenverhältnis beträgt somit vorzugsweise 1 :1. The load receptacles preferably comprise adjustable spacing, i. transversely to the longitudinal extent of displaceable tines. Usually, the tines are always displaced by the same length at a fork adjustment. The piston rod-side annular surface of a differential cylinder is thus preferably chosen to be the same size as the piston-side surface of the other differential cylinder. The area ratio is thus preferably 1: 1.
Solange keine Undichtigkeiten auftreten, erfolgt die Verlagerung der Zinken immer in der durch das Flächenverhältnis bestimmten Abhängigkeit. Da jedoch Hydraulikzylinder stets eine gewisse Leckage aufweisen, die mit zunehmender Betriebsdauer und zunehmenden Betätigungskraftunterschieden zwischen den beiden Zinken ansteigt, kann es insbesondere nach einer Vielzahl von Betätigungszyklen dazu kommen, dass das Hydraulikmedium zwischen dem von dem kolbenstan- genseitigen Ringvolumen, dem kolbenseitigen Volumen und dem von der Verbindung dieser beiden Volumina umschlossenen inneren Volumen und dem sich von diesem inneren Volumen über die Kolben der Differentialzylinder abgegrenzten äußeren Volumen übertritt. In einem solchen Falle ändert sich die„Nullstellung" der Zinken zueinander. Um für einen solchen Fall die Möglichkeit einer einfachen Volumenkorrektur zu schaffen, umfassen die Differentialzylinder vorzugsweise in zumindest einer ihrer Endstellungen Überströmeinrichtungen, mit Hilfe welcher übergetretenes Hydraulikmedium in das jeweilige Volumen zurückgeführt werden kann. As long as no leaks occur, the displacement of the tines always takes place in the dependency determined by the area ratio. However, since hydraulic cylinders always have a certain amount of leakage, which increases with increasing operating time and increasing differences in actuating force between the two tines, it can happen, in particular after a plurality of operating cycles, that the hydraulic medium is between the piston rod-side annular volume, the piston-side volume and the piston surrounded by the connection of these two volumes enclosed inner volume and the volume defined by this inner volume on the piston of the differential cylinder outer volume. In such a case, the "zero position" of the tines to each other changed.To provide in such a case the possibility of a simple volume correction, the differential cylinder preferably comprise in at least one of its end positions overflow, by means of which overflowed hydraulic medium can be returned to the respective volume ,
Diese Überströmeinrichtungen können - besonders bevorzugt - eine Bypassboh- rung in einem Zylindergehäuse umfassen, deren Strömungswiderstand groß gegenüber demjenigen der restlichen von dem Hydraulikmedium durchströmten Vo- lumina der Differentialzylinder und deren Zuleitungen ist. Für den Fall, dass die Zinken sich nicht in die Nullstellung zurückverlagern, mit anderen Worten: das beispielsweise bei der vollständig eingefahrenen Stellung der Kolbenstange des einen Differentialzylinders sich die Kolbenstange des anderen Differentialzylinders noch in einer ausgelenkten Position befindet, muss die Zufuhr des Hydraulikmedi- ums in dieser Betätigungsrichtung lediglich so lange weiter aufrechterhalten werden, bis über diese Bypassbohrung das zum Erreichen auch der Nullstellung des zweiten Zinkens nötige Volumen des Hydraulikmediums übergetreten ist. Es versteht sich, dass nicht nur zwei Differentialzylinder in der beschriebenen Weise in Reihe geschaltet werden können. Es ist dies auch mit einer größeren Anzahl möglich, so dass der erfindungsgemäße Gabelträger auch mit einer größeren Anzahl von Zinken bestückt sein kann, wenn dies beispielsweise für spezielle Anwendungen vorteilhaft ist. These overflow devices can-particularly preferably-comprise a bypass bore in a cylinder housing whose flow resistance is large compared to that of the remaining flow through the hydraulic medium. lumina of the differential cylinder and their leads is. In the event that the tines do not shift back to the zero position, in other words: for example, in the fully retracted position of the piston rod of a differential cylinder, the piston rod of the other differential cylinder is still in a deflected position, the supply of hydraulic medium in this direction of actuation, only continue to be maintained until the volume of the hydraulic medium required to reach the zero position of the second tine has been transferred via this bypass bore. It is understood that not only two differential cylinders can be connected in series in the manner described. This is also possible with a larger number, so that the fork carriage according to the invention can also be equipped with a larger number of tines, if this is advantageous, for example, for special applications.
Die Erfindung betrifft somit auch ein Flurförderzeug, insbesondere einen Gabelstapler, mit einem Gabelträger der vorbeschriebenen Art. The invention thus also relates to an industrial truck, in particular a forklift, with a fork carriage of the type described above.
In der Zeichnung ist ein Ausführungsbeispiel eines erfindungsgemäßen Gabelträ- gers dargestellt. Es zeigen: The drawing shows an embodiment of a Gabelträ- gers invention is shown. Show it:
Fig. 1 den Gabelträger in einer perspektivischen Ansicht von schräg vorn; Figure 1 shows the fork carriage in a perspective view obliquely from the front.
Fig. 2 denselben Gabelträger in einer perspektivischen Ansicht von schräg hin- ten; FIG. 2 shows the same fork carriage obliquely in a perspective view; FIG.
Fig. 3 ein Hydraulikschema des Gabelträgers gemäß Fig. 1 und 2, sowie Fig. 3 is a hydraulic diagram of the fork carriage according to FIGS. 1 and 2, as well
Fig. 4 das Hydraulikschema eines herkömmlichen Gabelträgers. Fig. 4 shows the hydraulic diagram of a conventional fork carrier.
Bei dem in Fig. 1 als Ganzes mit 100 bezeichneten Gabelträger ist aus Gründen der Übersichtlichkeit lediglich die in dieser Ansicht linke Lastaufnahme 1 , die einen Zinken 1 a umfasst, gestrichelt dargestellt. Der Zinken 1 a ist verbunden oder eingehängt mit einem ersten Schlitten 2, der quer zur Längserstreckung des Zinkens verlagerbar an Schienen 3, 3' gelagert ist. An den Schienen 3, 3' ist ein weiterer Schlitten 2' ebenfalls verlagerbar gelagert, welcher der Montage eines weiteren, in der Zeichnung nicht dargestellten Zinkens dient. Der in Fig. 1 links, in Fig. 2 dementsprechend rechts dargestellte Schlitten 2 ist mit der Kolbenstange 6' des in Fig. 1 und 2 oben dargestellten Differentialzylinders 4* verbunden. Dessen Gehäuse 5' ist an einem Traggestell 7 des Gabelträgers 100 befestigt. For the sake of clarity, only the left in this view load bearing 1, which includes a prong 1 a, shown in phantom in the illustrated in Fig. 1 as a whole with 100 fork carriage. The tine 1 a is connected or suspended with a first carriage 2, which is transverse to the longitudinal extent of the tine displaceable on rails 3, 3 'is mounted. On the rails 3, 3 ', a further carriage 2' is also mounted displaceably, which serves to mount a further, not shown in the drawing tine. The carriage 2 shown on the left in FIG. 1, in FIG. 2 on the right, is connected to the piston rod 6 'of the differential cylinder 4 * shown in FIGS. 1 and 2 above. Whose housing 5 ' is attached to a support frame 7 of the fork carriage 100.
Der in Fig. 1 rechts und dementsprechend in Fig. 2 links dargestellte Schlitten 2' ist dementsprechend mit der Kolbenstange 6 des in der Zeichnung unten darge- stellten Differentialzylinders 4, dessen Gehäuse 5 ist mit dem Traggestell 7 verbunden. The slide 2 'shown on the right in FIG. 1 and accordingly on the left in FIG. 2 is accordingly connected to the piston rod 6 of the differential cylinder 4 shown in the drawing below, whose housing 5 is connected to the support frame 7.
Wie insbesondere Fig. 2 und 3 entnommen werden kann, ist das kolbenstangen- seitige Ringvolumen 8 des oberen Differentialzylinders 4' über eine Verbindungs- leitung 9 mit dem kolbenseitigen Volumen 10 des unteren Differentialzylinders 4 verbunden. Die Volumina 8 und 10 sowie das Innenvolumen der Verbindungsleitung 9 bilden somit ein inneres Volumen, welches über die Kolben 11 , 11 ' von einem äußeren Volumen hydraulisch im wesentlichen getrennt ist. Das äußere Volumen wird gebildet durch das kolbenseitige Volumen 12 des oberen Differential- Zylinders 4', durch das kolbenstangenseitige Ringvolumen 13 des unteren Differentialzylinders 4 sowie der Volumina von Hydraulikleitungen 14, 14', über welche das Volumen 12 und das Ringvolumen 13 an eine Hydraulikdruckquelle 15 angeschlossen sind. Die Differentialzylinder 4, 4' sind jeweils mit einer Überströmeinrichtung 16, 16' ausgerüstet, über welche in den in Fig. 3 dargestellten, eingefah- renen Endstellungen der Kolben 11 , 11 ' der Differentialzylinder Hydraulikmedium von dem kolbenseitigen Volumina 10, 12 in die kolbenstangenseitigen Ringvolumina 8, 13 überströmen kann. Die Überströmeinrichtungen können das Überströmen wahlweise freigebende Ventileinrichtungen umfassen. Sie können jedoch ebenfalls als Bypassleitungen 17, 17' ausgebildet sein, die einen erheblich höhe- ren Strömungswiderstand aufweisen als die weiteren Hydraulikvolumina. As can be seen in particular from FIGS. 2 and 3, the piston rod-side annular volume 8 of the upper differential cylinder 4 'is connected via a connecting line 9 to the piston-side volume 10 of the lower differential cylinder 4. The volumes 8 and 10 and the internal volume of the connecting line 9 thus form an internal volume which is hydraulically substantially separated from the pistons 11, 11 'by an external volume. The outer volume is formed by the piston-side volume 12 of the upper differential cylinder 4 ', by the piston rod-side annular volume 13 of the lower differential cylinder 4 and the volumes of hydraulic lines 14, 14', via which the volume 12 and the annular volume 13 to a hydraulic pressure source 15th are connected. The differential cylinders 4, 4 'are each equipped with an overflow device 16, 16', via which, in the end positions of the pistons 11, 11 'of the differential cylinders shown in FIG. 3, hydraulic fluid is supplied from the piston-side volumes 10, 12 into the piston rod side Ring volumes 8, 13 can flow over. The overflow devices may comprise the overflow selectively releasing valve means. However, they can also be designed as bypass lines 17, 17 ', which have a considerably higher flow resistance than the other hydraulic volumes.
Bei dem in der Zeichnung dargestellten Ausführungsbeispiel ist die Ringfläche 18 der Kolbenstangenseite des Differentialzylinders 4 genauso groß gewählt wie die Fläche 19 der Kolbenseite des Differentialzylinders 4. Wird nun über die Hydraulik- leitung 14' ein Volumenstrom des Hydraulikmediums dem Volumen 12 zugeführt, d.h. erfolgt ein Volumenstrom in Richtung des durchgezogenen Pfeiles in Fig. 2, so wird der Kolben 11 gemäß Fig. 3 nach rechts verlagert. Das Ringvolumen 8 wird hierdurch verkleinert. Das hierdurch verdrängte Hydraulikmedium wird über die Verbindungsleitung 9 dem kolbenseitigen Volumen 10 des unteren Differenti- alzylinders 4 zugeführt. Da die Ringfläche 18 und die Fläche 19 gleich groß sind, wird hierbei der Kolben 1 1 ' um dieselbe Strecke wie der Kolben 1 1 verlagert. Entsprechendes geschieht in umgekehrter Richtung, wenn ein Volumen über die Hydraulikleitung 14 in der durch gestrichelten Pfeil in Fig. 2 symbolisierten Richtung dem kolbenstangenseitigen Ringvolumen 13 des unteren Differentialzylinders 4 zugeführt wird. In the embodiment shown in the drawing, the annular surface 18 of the piston rod side of the differential cylinder 4 is selected to be the same size as the surface 19 of the piston side of the differential cylinder 4. Is now on the hydraulic line 14 'a volume flow of the hydraulic medium to the volume 12 is supplied, that is, a volume flow in the direction of the solid arrow in Fig. 2, the piston 11 is displaced as shown in FIG. 3 to the right. The ring volume 8 is thereby reduced. The hydraulic medium displaced as a result is supplied via the connecting line 9 to the piston-side volume 10 of the lower differential cylinder 4. Since the annular surface 18 and the surface 19 are the same size, in this case the piston 1 1 'is displaced by the same distance as the piston 1 1. The same happens in the reverse direction when a volume via the hydraulic line 14 in the symbolized by dashed arrow in Fig. 2 direction the piston rod side annular volume 13 of the lower differential cylinder 4 is supplied.
Die Verlagerung der Kolben 11 , 11 ' der Differentialzylinder 4, 4' erfolgt somit stets in einer strengen Abhängigkeit voneinander. The displacement of the pistons 11, 11 'of the differential cylinder 4, 4' thus always takes place in a strict dependence on each other.
Wie aus Fig. 4, die das Hydraulikschema eines herkömmlichen Gabelträgers zeigt, sinnfällig wird, ist dies bei der parallelen Ansteuerung der Differentialzylinder nicht sichergestellt. Denn hier hängt der jeweilige Verlagerungsweg davon ab, wie der Volumenstrom des Hydraulikmediums über einen Längenteiler 20 verteilt wird. As is apparent from Fig. 4, which shows the hydraulic diagram of a conventional fork carrier, is obvious, this is not ensured in the parallel control of the differential cylinder. Because here the respective displacement depends on how the volume flow of the hydraulic medium is distributed over a length divider 20.
Bezugszeichenliste: LIST OF REFERENCE NUMBERS
100 Gabelträger 100 fork carriage
1 Lastaufnahme  1 load suspension
1 a Zinken  1 a prongs
2, 2' Schlitten  2, 2 'slide
3, 3' Schienen  3, 3 'rails
4, 4' Differentialzylinder  4, 4 'differential cylinder
5, 5' Gehäuse  5, 5 'housing
6, 6' Kolbenstange  6, 6 'piston rod
7 Traggestell  7 support frame
8 Ringvolumen  8 ring volume
9 Verbindungsleitung  9 connection line
10 Volumen  10 volumes
11 , 11 ' Kolben  11, 11 'pistons
12 Volumen  12 volumes
13 Ringvolumen  13 ring volume
14, 14' Hydraulikleitungen  14, 14 'hydraulic lines
15 Hydraulikdruckquelle  15 hydraulic pressure source
16, 16' Überströmeinrichtung  16, 16 'overflow device
17, 17' Bypassleitungen  17, 17 'bypass lines
18 Ringfläche  18 ring area
19 Fläche  19 area
20 Mengenteiler  20 flow divider

Claims

Patentansprüche: claims:
1. Gabelträger (100) für einen Gabelstapler, 1. fork carriage (100) for a forklift,
mit einem Traggestell (7),  with a support frame (7),
mit mindestens zwei Lastaufnahmen (1 ), die derart verlagerbar an dem Traggestell (7) gelagert sind, dass ihr Abstand zueinander veränderbar ist, wobei jeder Lastaufnahme (1 ) ein hydraulisch betätigbarer Differentialzylinder (4, 4') zum Bewirken der Verlagerung zugeordnet ist,  with at least two load receptacles (1) which are mounted so displaceably on the support frame (7) that their distance from each other is variable, each load receiving (1) is assigned a hydraulically actuated differential cylinder (4, 4 ') for effecting the displacement,
dadurch gekennzeichnet,  characterized,
dass das kolbenstangenseitige Ringvolumen (8) eines Differentialzylinders (4') mit dem kolbenseitigen Volumen (10) eines anderen Differentialzylinders (4) verbunden ist, und dass die kolbenstangenseitige Ringfläche (18) des einen Differentialzylinders (4') in einem vorbestimmten Verhältnis zur kolbenseitigen Fläche (19) des anderen Differentialzylinders (4) steht.  in that the piston rod side annular volume (8) of one differential cylinder (4 ') is connected to the piston side volume (10) of another differential cylinder (4), and in that the piston rod side annular surface (18) of the one differential cylinder (4') is in a predetermined relationship to the piston side Surface (19) of the other differential cylinder (4) is.
2. Gabelträger nach Anspruch 1 , dadurch gekennzeichnet, dass das Verhältnis 1 :1 beträgt. 2. fork carriage according to claim 1, characterized in that the ratio is 1: 1.
3. Gabelträger nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass die Differentialzylinder (4, 4') in zumindest einer der Endstellungen eine Überströmeinrichtung (16, 16') umfassen. 3. fork carriage according to claim 1 or 2, characterized in that the differential cylinder (4, 4 ') in at least one of the end positions an overflow device (16, 16').
4. Gabelträger nach Anspruch 3, dadurch gekennzeichnet, dass die Über- Strömeinrichtung (16, 16') eine Bypassleitung (17, 17') umfasst, deren Strömungswiderstand groß gegenüber demjenigen der Hydraulikvolumina der Dif- ferentialzylinderanordnung ist. 4. fork carriage according to claim 3, characterized in that the overflow device (16, 16 ') comprises a bypass line (17, 17') whose flow resistance is large compared to that of the hydraulic volumes of the dif ferentialzylinderanordnung.
5. Flurförderzeug mit einem Gabelträger nach einem der Ansprüche 1 bis 4. 5. truck with a fork carriage according to one of claims 1 to 4.
PCT/EP2010/060327 2009-08-07 2010-07-16 Fork carriage for a forklift WO2011015442A1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
AU2010280949A AU2010280949A1 (en) 2009-08-07 2010-07-16 Fork carriage for a forklift
RU2011101955/11A RU2533627C2 (en) 2009-08-07 2010-07-16 Fork carriage of fork-lift truck
EP10734979.7A EP2451738B1 (en) 2009-08-07 2010-07-16 Fork carriage for a forklift
PL10734979T PL2451738T3 (en) 2009-08-07 2010-07-16 Fork carriage for a forklift

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE202009005118.8 2009-08-07
DE202009005118 2009-08-07

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WO2011015442A1 true WO2011015442A1 (en) 2011-02-10

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EP (1) EP2451738B1 (en)
AU (1) AU2010280949A1 (en)
PL (1) PL2451738T3 (en)
RU (1) RU2533627C2 (en)
WO (1) WO2011015442A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9744862B2 (en) 2011-09-28 2017-08-29 Continental Teves Ag & Co. Ohg Slip-controlled braking system for electrically driven motor vehicles
WO2022122101A1 (en) * 2020-12-08 2022-06-16 Logitrans A/S Clamp device and a mobile lift system with the clamp device

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE9104137U1 (en) * 1991-04-05 1991-06-06 Kinshofer Greiftechnik Gmbh, 8176 Waakirchen, De
US5088880A (en) * 1990-12-03 1992-02-18 Caterpillar Industrial Inc. Fluid operated fork positioning control system
DE9211128U1 (en) * 1992-08-19 1993-05-19 Kinshofer Greiftechnik Gmbh, 8176 Waakirchen, De
DE9404736U1 (en) * 1994-03-21 1995-07-20 Kinshofer Greiftechnik Device for controlling two linear motors, especially hydraulic cylinders
DE19943356A1 (en) * 1998-09-11 2000-05-04 Polz S A R L Device for gripping one or more pallets of different dimensions on the end face

Family Cites Families (2)

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Publication number Priority date Publication date Assignee Title
SU407835A1 (en) * 1971-10-05 1973-12-10 CARGO CARRIER OF INDUSTRIAL LOADER
SU1279945A1 (en) * 1985-05-06 1986-12-30 Могилевский Машиностроительный Институт Gripping device to loader

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5088880A (en) * 1990-12-03 1992-02-18 Caterpillar Industrial Inc. Fluid operated fork positioning control system
DE9104137U1 (en) * 1991-04-05 1991-06-06 Kinshofer Greiftechnik Gmbh, 8176 Waakirchen, De
DE9211128U1 (en) * 1992-08-19 1993-05-19 Kinshofer Greiftechnik Gmbh, 8176 Waakirchen, De
DE9404736U1 (en) * 1994-03-21 1995-07-20 Kinshofer Greiftechnik Device for controlling two linear motors, especially hydraulic cylinders
DE19943356A1 (en) * 1998-09-11 2000-05-04 Polz S A R L Device for gripping one or more pallets of different dimensions on the end face

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9744862B2 (en) 2011-09-28 2017-08-29 Continental Teves Ag & Co. Ohg Slip-controlled braking system for electrically driven motor vehicles
WO2022122101A1 (en) * 2020-12-08 2022-06-16 Logitrans A/S Clamp device and a mobile lift system with the clamp device

Also Published As

Publication number Publication date
EP2451738B1 (en) 2013-07-10
RU2011101955A (en) 2012-07-27
AU2010280949A1 (en) 2011-02-10
EP2451738A1 (en) 2012-05-16
PL2451738T3 (en) 2013-12-31
RU2533627C2 (en) 2014-11-20

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