DE9013488U1 - Mobile crane with a telescopic boom - Google Patents

Description

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90-0778 G-sb 25.09. 1990

Liebherr-Werk Ehingen GmbH, 7930 Ehingen/Donau

Mobile crane with a telescopic boom

The invention relates to a fahxhsix-aa Ki &lgr;

with a telescopic boom, the telescopic sections of which can be extended and retracted by a single or multi-stage telescopic cylinder, the piston rod of which is hinged to the boom end piece of the outer boom section, and

with a luffing tip hinged to the upper end of the inner telescopic section directly or via at least one boom intermediate piece, which preferably consists of a needle boom.

Mobile cranes of this type have a considerably greater lifting height and reach due to the tip that is hinged in the area of the roller head of the inner telescopic section, which is usually designed as a so-called folding tip, which significantly increases the area of application of the mobile crane. However, the luffing ability of the boom tip compared to the telescopic boom makes it necessary to provide additional devices for luffing the boom tip, which are particularly complex because they are attached to the different telescopic sections.

-2-Telescopic booms must be adaptable.

The object of the invention is therefore to provide a crane of the type specified at the outset, the tip of which is provided with a tilting device which requires little constructional effort and requires only a small amount of space .

According to the invention, this task is solved in a crane of the generic type in that a hydraulic piston-cylinder unit is provided for rocking the tip, which tends to pivot into its lowered position under the effect of gravity, the rocking cylinder of which is provided with only one line for supplying and discharging hydraulic oil, which encloses the cylinder annular space of the single-stage telescopic cylinder or the cylinder of the outer stage of the telescopic cylinder and the line system leading to it and which contains, as a further line part, a pipe and/or hose line connected to the cylinder annular space, and that a hydraulic oil control is provided which, when the cylinder chamber or chambers used for the execution are closed, controls the supply and discharge of hydraulic oil to the rocking cylinder via the line system, the cylinder annular space and the further line part.

In the crane according to the invention, a complex luffing mechanism (ie luffing of the boom tip) is dispensed with and instead only a single hydraulic cylinder is provided for luffing the boom tip. In order to be able to supply this luffing cylinder with hydraulic oil through only a single line, the tip is arranged at an incline in all operating positions in such a way that it strives to swing into its lowered position under the effect of gravity. In this way, the hydraulic cylinder only needs to swing the tip upwards, while the opposite luffing movement is carried out under the weight of the

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the tip and the attached load by gravity.

According to the invention, a particularly simple supply of the luffing cylinder with hydraulic oil is achieved by including the telescopic cylinder in the supply line system in the shaft, so that the line system is reduced by its length. Since the telescopic cylinder and the line system leading to it are part of the supply line of the luffing cylinder, devices that lengthen or shorten the hydraulic line leading to the luffing cylinder according to the extended or extended state of the telescopic boom are also omitted. With the crane according to the invention, only a pipe and/or hose line from the external telescopic cylinder to the luffing cylinder must be provided. This can usually be accomplished with simple means because the length to be bridged is relatively short and the telescopic part of the telescopic boom is bridged by the line created by the telescopic cylinder.

With telescopic booms, it is possible not to extend and retract all telescopic boom sections directly using a single or multi-stage telescopic cylinder. Rather, it is also possible to extend and retract the inner section or sections using appropriately reeved ropes. According to an inventive development, it is therefore provided that with the additional arrangement of one or more inner telescopic sections that can be extended and retracted using appropriate rope reeving, a hydraulic hose that can be wound onto a hose reel is provided, which creates the connection between the cylinder ring chamber and the luffing cylinder.

In the crane according to the invention, due to the small length to be bridged by the hydraulic hose, the hose reel can be made correspondingly small and can be mounted in the inner telescopic section or its roller head.

The tip which can be tilted and is articulated on the telescopic boom can have a considerable length and consequently also a considerable weight. According to an inventive further development, for which independent protection is claimed, it is therefore provided that the tip, which preferably consists of a needle boom, has an articulated &ngr;

Connection to the retracted telescopic boom can be folded g and a hydraulic swivel to swivel the tip %

cylinder or a swivel motor is provided.

y An embodiment of the invention is described below '■

explained in more detail using the drawing. In this, If

Fig.1 a side view of the outer end of the 1 Telescopic boom with retracted 1 Shots, whose inner shot over a f

hinged boom intermediate piece a .

rocker needle tip, I

Fig.2 a view of the boom intermediate piece with <: hinged luffing boom tip in direction '

of arrow A in Fig.l,

Fig.3 a view corresponding to Fig.l with §

lowered tip, 1

Fig.4 a longitudinal section through a two-stage telescopic cylinder in a schematic representation and

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Fig.5 is a side view of an intermediate piece that can be coupled to the first shot of the rocking tip during the coupling process.

The telescopic boom 1 with the outer protection 2 and the telescopic sections 3 to 6, of which the inner section 6 carries the roller head 7 at its outer end, is of a known design and therefore does not need to be described in more detail here. The telescopic boom 1 is pivotably mounted about a horizontal axis in the upper carriage of a mobile crane via a boom linkage piece which closes off the inner end of the outer section 2. A luffing cylinder is provided for luffing the telescopic boom, the cylinder of which is pivotably mounted in the upper carriage and the piston rod of which is pivotally mounted on the outer boom section 2.

A boom intermediate piece 8 is bolted to the corresponding coupling pieces of the roller head 7, at the outer end of which the tip 10 consisting of a needle boom is hinged on the inner edge around the axis 9. The boom intermediate piece 8 has a back support 11 at its upper end, at the outer end of which the luffing cylinder 12 for the tip 10 is hinged, the piston rod of which is hinged in the area of the first section 13 of the tip. Deflection rollers 14, 14' can be mounted in the area of the outer end of the first section 13 of the tip 10 or also at the outer end of the tip 10 in the manner shown in Figs. 1 and 3, over which the hoist rope then runs to the roller(s) 15, 15' of the load hook. If the lubricating rope is not guided over the rollers of the roller head 7, it runs in the manner shown in Fig. 1 and 3 over a deflection roller 16 mounted on the backrest 11.

In the example shown, the extendable sections 3 to 6 of the five-part telescope

The boom is telescoped out by a two-stage hydraulic telescoping cylinder and a correspondingly reeved two-way pulley. The two-stage telescoping cylinder used for telescoping is shown schematically in the longitudinal section in Fig. 4. It consists of a piston rod 20, the piston 21 of which is guided in the cylinder 22, which in turn forms the piston rod for the piston 23, which is guided in the outer cylinder 24. The inner edges of the cylinders 22, 24 have radially inwardly projecting ring collars 25, 26, so that cylinder ring spaces 27, 28 are formed between the steps formed by these and the pistons 21, 23. The piston rod 20 is hollow and has a central tube 30 in which a tube 31 is guided telescopically, which is connected to the piston 23 and opens into the chamber of the cylinder 24 via a bore 32 passing through the piston 23. Connected to the piston 23 is another tube 35 which concentrically surrounds the tube 31, which is guided in a sealing manner in a bore of the piston 21 and also encloses the tube 30 to form an annular space 36.

The annular space 37, which is formed between the tube 30 and the inner wall 41 of the piston rod 20, is connected to the cylinder annular space 27 by a line 38 leading through the piston 21. The cylindrical annular space 28 of the outer cylinder 24 is connected by a line 40 to the annular space 39, which is formed between the tubes 31 and 35. In this way, the cylindrical annular space 28 is also connected to the annular space 37 of the piston rod 20.

The piston rod 20 is provided at its front end with a bore 44 which is connected via the tube 30 and the tube 31 guided telescopically therein and the bore 32 to the cylinder chamber 45 of the outer cylinder 24 in

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The piston rod 20 is provided with a further bore 46 which passes through the piston 21 and ends in the large cylindrical annular groove 47 of the cylinder 22. Finally, the front end of the piston rod 20 is provided with a third bore 48 which ends in the annular groove between the tube 30 and the cylindrical wall 41.

The cylindrical ring 28 is connected through a bore to the line 50, which leads to the tilting cylinder 12 of the tilting tip 10. Since at least the outer telescopic section 5 can be telescopically extended by means of a corresponding pulley block, the line 50 is connected to a hydraulic hose, which can be wound onto a hose reel 52, which is mounted on the roller head 7.

The piston rod 20 of the two-stage telescopic cylinder 55 is connected in a known and not shown manner to the inner side of the boom linkage piece. The telescopic cylinder 55 is connected in a known and therefore also not shown manner to the boom sections that can be telescopically extended by it.

A line (not shown) leads from the hose reel 52 for the hydraulic hose to the tilting cylinder 12.

A particular advantage of the inventive telescopic boom with the tip that can be tilted via the tilting cylinder 12 is that the tilting cylinder is hinged to the first section of the boom positions 10, so that with this section, further boom intermediate sections of the tilting tip can be picked up and connected only by pivoting the telescopic boom 1 and the tilting section 13. The telescopic boom 1 with intermediate section 8 and the

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The pivotable section 13 of the tip only needs to be lowered in the manner shown in Fig. 5 so that the coupling pieces 60 of the section 13 can be coupled to the coupling pieces of a boom intermediate piece 61 lying on the ground or on a beam. If the pivotable section 13 is pivoted upwards above the pivot cylinders 51, the coupling pieces 52 also come into contact with the pivot cylinders 52 so that they can be coupled. In a corresponding manner, further intermediate pieces or ^the end piece of the tip 10 can then be coupled to the intermediate piece 51.

Claims (4)

90-0778 6-sb 25.09.1990 Llebherr-Verk Ehlngen Gmba, 7930 fSMngen/Poaau Mobile crane with a partially movable boom 1. Mobile crane with a telescopic boom, the telescopic sections of which can be extended and retracted by a single or multi-stage telescopic cylinder, the piston rod of which is linked to the boom linkage of the outer boom section, and with a rocking tip hinged to the upper end of the inner telescopic weft directly or via at least one boom intermediate piece, which preferably consists of a needle feeder, characterized, that for rocking the tip (10), which tends to pivot into its lowered position under the effect of gravity, a hydraulic piston-cylinder unit is provided, the rocking cylinder (12) of which is provided with only one line for supplying and discharging hydraulic oil , which lines the cylinder annular space of the single-stage telescopic cylinder or the cylinder (24) of the outer stage of the telescopic cylinder (55) and the -2- leading line system (48,37,36,40) and which contains, as a further line part, a pipe and/or hose line (50,52) connected to the cylinder annular space (28), and that a hydraulic oil control is provided which, upon completion of the operation to the one or more of the &uefaiir®j» ulssi&oS^a &Zgr;&ggr;&Igr;&Igr;&idigr;&iacgr;&aacgr;&&tgr;* always or chambers (45,47) via the line system (48,37,36,40), the cylinder annular space (28) and the further line part (50,52), controls the supply and discharge of hydraulic oil to the rocker cylinder (12). 2. Crane according to claim 1, characterized in that with the additional arrangement of one or more inner telescopic sections that can be extended and retracted via corresponding rope reeving, a hydraulic hose that can be wound onto a hose reel (52) is provided, which establishes the connection between the cylinder ring chamber (28) and the luffing cylinder (12). 3. Crane according to claim 1 or 2, characterized in that the hose reel (52) is mounted in the inner telescopic section or on its roller head (7). 4. Crane, in particular according to one of claims 1 to 3, characterized in that the luffing tip 10 can be folded via an articulated connection to the retracted telescopic boom (1) and a hydraulic swivel cylinder or a swivel motor is provided for swiveling the luffing tip (10) for folding.