WO2019134943A1

WO2019134943A1 - Vehicle crane having a main boom extension that can be luffed hydraulically

Info

Publication number: WO2019134943A1
Application number: PCT/EP2019/050108
Authority: WO
Inventors: Rolf Heintz
Original assignee: Terex Global Gmbh
Priority date: 2018-01-05
Filing date: 2019-01-03
Publication date: 2019-07-11
Also published as: EP3735388A1; EP3735388B1; DE202018100059U1

Abstract

The invention relates to a vehicle crane (1) having a main boom (4) and having a main boom extension (5) that is attached to the main boom (4) and can be luffed by means of a luffing cylinder (14). The aim of the invention is to provide a vehicle crane, the expenditure on maintenance and assembly of which is reduced and which can thus be provided more economically. This aim is achieved, according to the invention, in that the luffing cylinder (14) is connected to a hydraulic hose (13) in such a way that the hydraulic fluid either flows to the luffing cylinder (14) or flows away from the luffing cylinder (14), wherein the luffing cylinder (14) is connected to the hydraulic hose (13) by means of a single flow channel for supplying hydraulic fluid, and the hydraulic hose (13) is led along the main boom (4).

Description

Mobile crane with a hydraulically tiltable main boom extension

The invention relates to a vehicle crane with a main boom and with a hinged to the main boom and tilted by means of at least one rocking cylinder main boom extension.

The German Utility Model DE 20 2004 020 760 U1 discloses a mobile crane with a main boom, which consists of a base box and telescopic telescopic and telescopic shots therein. On a head of the main boom, a main boom extension is articulated which is pivotable about a luffing axis by means of a luffing cylinder relative to the main boom. The luffing cylinder is in the usual way a hydraulic piston-cylinder unit. The luffing cylinder is supplied with hydraulic energy via a self-sufficient hydraulic power unit with a combustion engine which is arranged on the head of the main boom or particularly preferably on one foot of the main boom extension. Thus, a decentralized

Ensuring supply of the piston-cylinder unit with hydraulic energy and long supply hoses for the luffing cylinder can be dispensed with. However, the decentralized arranged in the region of the head of the main boom hydraulic unit is also associated with disadvantages, since the entire weight of this

Hydraulic unit must be taken with each adjustment of the main boom. Also, the maintenance and thus the costs to ensure adequate reliability of the high-level hydraulic unit are increased. Also, in this utility model already described, instead of a decentralized hydraulic unit to arrange a driven or spring-biased hose reel for hydraulic lines to supply the luffing cylinder to the base box or on a superstructure of the mobile crane. Because the

Hose drum as a function of the length of the hydraulic line has a comparatively large diameter, this can adversely affect a height, in particular a transport height of the mobile crane. For a road trip, in which the height of the mobile crane is limited to 4 meters, therefore usually the hose reel is removed and reassembled at the site, resulting in an increased assembly costs. The published patent application DE 24 06 57 A1 discloses a crane with a telescopic main boom and luffing jib. A hydraulic cylinder used for telescoping a cantilever foot of the luffing jib is described as "single acting". About a supply of hydraulic fluid to the hydraulic cylinder, no information is given.

The document JP S63 46 465 also describes a main boom with a hydraulically tiltable luffing jib via a single-acting luffing cylinder. As

Hydraulic fluid reaches the luffing cylinder is open.

The invention is therefore based on the object to provide a vehicle crane with a hydraulically tiltable main boom extension, the

Maintenance and installation costs is reduced and thus can be provided cheaper.

This object is achieved by a vehicle crane having the features of claim 1. In the dependent claims 2 to 12 advantageous embodiments of the invention are given.

A vehicle crane with a main boom and with a hinged to the main boom and tilted by means of at least one rocking cylinder

Hauptauslegerverlängerung is inventively improved in that the luffing cylinder is connected to a hydraulic hose in such a way that the hydraulic fluid flows either to the luffing cylinder or of the

Rocker cylinder flows away, wherein the luffing cylinder is connected to the hydraulic hose with a single flow channel for supplying hydraulic fluid and the hydraulic hose is guided along the main boom. The principle of the present invention can be described as operating a conventional double-acting hydraulic differential cylinder predominantly to fully in the manner of a single acting hydraulic differential cylinder to achieve the goal of using two parallel ones

Hydraulic hoses, in particular of twin hoses, to dispense with hydraulic fluid for supplying the hydraulic cylinder. The then only simple hydraulic hose builds smaller and is easier to wind, so that an associated hose reel can be built according to smaller and simpler. The simple hydraulic hose is to be understood as a hydraulic hose having only a flow channel for hydraulic fluid and thus seen in terms of time, the hydraulic fluid through the flow channel either to the

Rocker cylinder flows or flows away from the luffing cylinder. It could also be said that the hydraulic fluid either flows exclusively through the flow channel to the luffing cylinder or flows away exclusively from the luffing cylinder and thus only in one of the two in terms of time

Flow directions is operated. Thus, it is also understood that a twin tube or a hydraulic hose with more than two flow channels could be operated in an inventive manner, when the individual flow channels are flowed through in parallel and only in a common flow direction. In such hoses then the above-described winding advantage could be omitted.

Advantageously, the hydraulic hose has a round cross section, whereby in particular a winding of the hydraulic hose is simplified.

The core idea of the present invention is thus to pressurize the luffing cylinder for rocking the main boom extension relative to the main boom via a flow channel with hydraulic fluid, in particular hydraulic oil, and for the return movement of the luffing cylinder predominantly the weight of the main boom extension or spring forces, in particular for angling from a steep 0 ° position of the main boom extension to use.

According to the invention, the rocking cylinder can thus be connected to a hydraulic hose with a single flow channel for supplying hydraulic fluid. The hydraulic fluid flows back and forth in the hydraulic hose. The

Hydraulic hose is guided along the main boom, in particular via Schlauchfüh- ments.

In a preferred embodiment of the invention, the luffing cylinder on a rod space and a cylinder space, wherein either only the rod space or only the cylinder space is connected to the hydraulic hose. The cylinder space or rod space not connected to the hydraulic hose is advantageously connected to the atmosphere without pressure. In a particularly preferred embodiment of the invention, the rocking cylinder on a rod space and a cylinder chamber, wherein either only the rod space or only the cylinder chamber is connected to the hydraulic hose and the cylinder chamber not connected to the hydraulic hose or

Rod space with a pressure medium, preferably with a gas, more preferably with nitrogen, is filled.

In a further embodiment of this invention, it is possible as a pressure medium next to gas or nitrogen on a cylinder side of the luffing cylinder to provide a hydraulic fluid, in particular hydraulic oil, which is then in communication with a gas storage. The use of a mechanical spring on the cylinder side of the rocking cylinder is conceivable. In an advantageous manner, it is also provided that the rocking cylinder is associated with a valve via which an outflow of the hydraulic fluid from the Wippzylin- and thus angling of the main boom extension is controllable.

In addition, it can be advantageously provided that the luffing cylinder is designed as a pull cylinder or as a pressure cylinder.

In a particularly advantageous manner, the rocking cylinder is acting unilaterally. By applying only one side of the luffing cylinder with hydraulic fluid can therefore be dispensed with a more expensive and therefore more expensive twin hose, which can twist during winding, whereby a Aufwickelradius is unintentionally increased.

In a particularly advantageous embodiment of the invention, the rocking cylinder on a rod space and a cylinder space, wherein the rod space and the cylinder chamber can be connected to the hydraulic hose. the

Rocking cylinders are assigned a switching valve and a bladder accumulator. Advantageously, in the cylinder chamber, the pressure surface on which a hydraulic fluid can act is increased relative to the pressure surface in the rod space around the engagement surface of a cylinder rod, so that consequently the cylinder chamber is charged with hydraulic fluid and hydraulic fluid is discharged from the rod chamber can flow out. The rod space can via the switching valve with the

Cylinder space or be connected to a bladder accumulator, which is filled with hydraulic fluid and gas. In this embodiment, the rocking cylinder is acted upon in the manner of a unilaterally acting rocker cylinder via a single flow channel with hydraulic fluid. Thus, even here can be dispensed with a complex and unfavorable twin tube.

Basically, a distinction is made between telescopic cranes and lattice boom cranes for mobile cranes. Telescopic cranes are characterized by the fact that the crane boom consists of several telescopically telescoping telescopic shots, whereas in a lattice boom crane, the boom consists of several rigidly interconnected lattice mast elements. In the present case, a mobile crane is understood to be a mobile crane with a telescopic boom or a crawler crane with a lattice boom.

In a further advantageous refinement of the vehicle crane, the main cutter can be telescoped and consists of a base box and further telescopic shots which can be telescoped in and out. The hydraulic hose for supplying hydraulic power to the luffing cylinder can be unwound from or wound onto a hose reel during the first and second telescoping of the main jib. In particular, the

Hydraulic hose in several layers on the hose drum similar to a rope or cable drum side by side and one above the other wound up.

In a particularly advantageous manner, the hose reel is arranged on the main boom, in particular on the base box.

By the execution of a hydraulic hose as the only flow channel and not only spiral winding the hose reel is reduced in diameter, so that advantageously an arrangement on the base box of the main boom even during transport is possible. On an elaborate assembly and

Dismantling for transport can be dispensed with.

It is advantageously provided that the vehicle crane has an undercarriage and a superstructure mounted rotatably thereon. An embodiment of the invention will be explained in more detail with reference to the following description. 1 shows a view of a mobile crane with a main boom and a main boom extension, each in a stored position and in an erected position, FIG.

FIG. 2 shows a detailed view of the section Z marked in FIG. 1 from the region of the coupling of the main boom extension to the main boom, FIG. 3 shows a schematic hydraulic circuit diagram with respect to the tilt cylinder,

FIG. 4 a shows a schematic hydraulic circuit diagram relating to the luffing cylinder with a bladder accumulator with a reversing valve in a first position,

FIG. 4b shows the hydraulic circuit diagram according to FIG. 4a with a change-over valve in a second position,

Figure 4c is a schematic hydraulic circuit diagram according to Figure 4a with a

Changeover valve in a third position and

FIG. 4d shows a schematic hydraulic circuit diagram according to FIG. 4a with a

Changeover valve in a fourth position. FIG. 1 shows a mobile crane 1 with an undercarriage 2 with driver's cab and five drive axles and with a superstructure 3 mounted on the undercarriage 2 via a slewing connection with a telescopic main boom 4

Main boom 4 is shown in a first almost horizontal stored position I and in a nearly vertical second position II. The main boom 4 is in the usual way via a hydraulic erection cylinder 16, which is supported on the uppercarriage 3 and the main boom 4, between the positions I and II teetering. In the erected position II, the main boom 4 is shown in its fully telescoped condition. The main boom 4 is as a telescopic boom with a base box 6 and four in a known manner on and austeleskopier- bar arranged telescopic shots 7 to 10 and thus the mobile crane 1 as

Telescopic crane trained. A free and upper end of the innermost telescopic weft 10 serves as a head 4a to which the main boom extension 5 is releasably secured. The main boom extension 5 can be used temporarily or permanently with the mobile crane 1 in order to achieve an overall length exceeding the maximum boom length of the main dolly 4. The main boom extension 5 is pivoted at its foot 5a about a rocking axis A pivotally connected to the head 4a of the main boom 4 via bolts. FIG. 1 shows the main boom extension 5 in a 0 ° -position, a 20 ° -position and a 40 ° -position. The degree refers to a Wippwinkel a between the main boom 4 and the main boom extension 5. In addition, the main boom extension 5 is formed in a conventional manner, at least partially as a lattice boom in truss tube construction and has a subsequent thereto box top. Of course, deviating from the exemplary embodiment shown here, the main boom extension 5 can also be configured overall as a lattice mast boom.

It is also indicated in FIG. 1 that the main boom extension 5 can be swiveled up and down about the rocking axis A oriented relative to the main boom 4 by means of a hydraulic rocker cylinder 14 substantially horizontally and parallel to a further rocking axis of the main dolly 4. In order to supply the luffing cylinder 14 with hydraulic energy, a hydraulic hose 13 is provided, which is connected at one end to the luffing cylinder 14 and is guided along the main feeder 4 or the telescoping shots 7, 8, 9, 10 to a hose reel 12. The hose reel 12 is arranged on and laterally next to the base box 6. In addition, the hose reel 12 is mounted about a horizontal and parallel to the rocking axis A arranged axis of rotation D. The hose drum 12 is driven or spring-biased for winding and unwinding of the hydraulic hose 13. Between the luffing cylinder 14 and the hose reel 12, the hydraulic hose 13 is additionally connected via hose guides 15 along the

Main boom 4 (see Figure 2) out. The hose guides 15 are respectively arranged at the upper ends or heads of the telescopic sections 7 to 10 (see Figure 2).

FIG. 2 shows a detailed view of the section designated Z in FIG. 1 from the area of the coupling of the main boom extension 5 to the section

Main boom 4. The main boom 4 and the main boom extension 5 are, however, in the horizontal stored position I, in which the telescopic shots 7 to 10 are not telescoped and the hydraulic hose 13 is completely wound on the hose reel 12. Also, the main boom extension 5 is aligned in extension to the main boom 4, ie the Rocking angle w is 0 °. To the main boom extension 5 against the

Main boom 4 to be able to actively angle in both directions, at least one luffing cylinder 14 is disposed between the head 4a of the main boom 4 and the foot 5a of the main boom extension 5. The rocker cylinder 14 is bolted with its housing 14a on the head 4a of the main boom 4 and with its piston rod 14b on the foot 5a of the main boom extension 5. In addition, the illustrated rocking cylinder 14 is designed as a single-acting hydraulic cylinder and as a pull cylinder. Of course, a reverse installation of the rocking cylinder 14 is conceivable. Likewise, the formation of the rocker cylinder 14 as a pressure cylinder instead of a pull cylinder is possible, in which case, however, is to make a different mechanical arrangement. On the housing 14a of the rocking cylinder 14, a hydraulic line 13a is connected, preferably in a

Rod region of the rocking cylinder 14 opens. This hydraulic line 13a is at its other end in the region of the head 4a of the main boom 4 to the

Hydraulic hose 13 connected. The hydraulic hose 13 fastened in the region of the head 4a of the main feeder 4 is guided to the hose reel 12 via one hose guide 15 per telescopic weft 7, 8, 9, 10. Each hose guide 15 preferably consists essentially of two opposite ones

arranged guide rollers with groove between which the hydraulic hose 13 is guided. The hose guides 15 are each arranged at the upper end of the telescopic shots 7, 8, 9, 10 or of the basic box 6.

According to the invention, the luffing cylinder 14 is connected to a hydraulic hose 13 in such a way that the hydraulic fluid either flows towards the luffing cylinder 14 or flows away from the luffing cylinder 14, so that only one hydraulic supply line with a single flow channel is required. Therefore, the hydraulic hose 13 is not as a twin line, but only as

Single line trained. This formed as a single line hydraulic hose 13 is multi-layered on the hose reel 12 and not only spiral and unwound. Preferably, the hose reel 12 has for this purpose hose grooves and flanged wheels at the edges of the hose reel 12 to assist an orderly winding. In the wound state, the individual line of the hydraulic hose 13 thus runs next to one another in each position and in layers one above the other. With a so-called multi-layer technique with preferably parallel grooving on the hose reel, the hydraulic hose 13 can be arranged in a multi-layered manner over one another be wound up. The multi-ply winding is made possible by special in the body of the hose reel milled cable grooves, which are partially parallel to the outer board and connected via so-called and about 120 ° to 180 ° offset intersections. The crossing areas ensure the required pitch per revolution of the drum and ensure a constant and pyramidal hose winding.

FIG. 3 shows a schematic hydraulic circuit diagram with respect to FIG

Rocking cylinder 14, of which only a rod space 14c of the housing 14a with

Hydraulic oil is supplied via the hydraulic hose 13 and the first hydraulic line 13 a with a valve 17. The hydraulic hose 13 which can be guided along the telescopic shots 7 to 10 (see FIGS. 1 and 2) and which is mounted on one

Hose drum 12 is wound, is fed in the region of the hose drum 12 via a second hydraulic line 13b by means of a pump 19 from a container 21 with hydraulic fluid, in particular hydraulic oil. When the hydraulic fluid is discharged from the rod space 14c, it flows through the first hydraulic line 13a, the valve 17, the hydraulic hose 13 and the second hydraulic line 13b back into the reservoir 21 via a return valve 20. A cylinder space 14d of the housing 14a can be depressurized in one embodiment in connection with the atmosphere. In the embodiment illustrated in FIG. 3, the cylinder space 14d is filled with gas, in particular nitrogen. In order to obtain a larger volume for the gas filling, an external gas reservoir 18 is connected to the cylinder chamber 14d. The gas reservoir 18 can also be designed as a bubble reservoir with gas filling, wherein hydraulic fluid, in particular hydraulic oil, is then present in the cylinder chamber 14d as a non-compressible pressure medium. Depending on the requirements, a gas filling in the cylinder chamber 14d without gas reservoir 18 may be sufficient.

In order to increase the gas volume a little, a piston rod 14b may additionally be made hollow. Then, the installation dimensions of the hydraulic cylinder 14 can be maintained. In addition, it is possible that instead of a pressure medium, a mechanical spring is arranged in the cylinder space 14d or outside in the mechanism.

Hereinafter, on the basis of FIGS. 1 to 3, a luffing and luffing of the main boom extension 5 with the aid of the luffing cylinder 14 will be described. Starting from the erected position II shown in FIG and the main boom extension 5 in 0 ° position is pressurized by the weight of the main boom extension 5 and a possible load on the main boom extension 5 via the piston rod 14 b, the hydraulic oil. For a luffing of the main boom extension 5, in particular in the 20 ° position or 40 ° position, hydraulic oil from the rod chamber 14 c via the valve 17, which is in particular an electrically controlled Senkbrems seat valve, be drained. At the same time, the gas or hydraulic oil relaxes in the cylinder chamber 14d or fills with atmospheric air. The necessary for the Aufwippen the main boom extension 5 hydraulic energy is in the form of

Hydraulic oil provided via the hydraulic hose 13, wherein only the ring side is acted upon with oil. At the same time, the gas or hydraulic oil is compressed in the cylinder space 14d or atmospheric air is forced out. By closing the valve 17, the oil pressure can be maintained, if necessary, and thus the rocking angle w.

The filling of the cylinder chamber 14d with compressed gas or pressurized hydraulic oil leads to a bias of the rocking cylinder 14, so that a faster teetering of the main boom extension 5 is possible. It is also advantageously possible, with the bias voltage and the oil pressure in the rod space 14c, to retract and extend the hydraulic cylinder 14 even without external forces, so that, for example, a bolting position can be approached during setup.

In principle, it is also possible to arrange the hose reel 12 on the uppercarriage 3. It can also be provided that the hydraulic line 13a is connected to a cylinder side of the rocking cylinder 14. Also, the

Rocking cylinder 14 instead of as a pull cylinder operated as a pressure cylinder, in which case the rod space and the cylinder space are exchanged and the cylinder chamber are filled with hydraulic fluid and the rod space with pressure medium. Alternatively, the hydraulic hose 13 can be connected directly to the rocker cylinder 14 without the Hydrauliklei device 13 a.

In addition, a further embodiment of the invention with a bladder accumulator 22 instead of a gas accumulator 18 is shown in FIGS. 4a to 4d. FIG. 4a shows a schematic hydraulic circuit diagram for the main boom 4 in the upright position II and the main boom extension 5 in the 0 ° position. In addition to the objects already described with corresponding reference numerals, a bladder accumulator 22 and a switching valve 23 are provided, and the first hydraulic line 13a is connected to the luffing cylinder 14 in a different manner. The first hydraulic line 13a is connected via the switching valve 23 with the

Rod space 14c and also connected to the cylinder space 14d. To the

Switching valve 23 and the bladder accumulator 22 and the hydraulic hose 13 is connected.

For teetering the main boom extension 5 by a small angle, in particular less than 10 °, preferably less than 5 °, particularly preferably less than 2 °, out of a steep position, in particular the 0 ° position, the changeover valve 23 is in the position shown in FIG first position. Here, the bladder accumulator 22 is filled with hydraulic fluid and decoupled from the hydraulic hose 13 and the first hydraulic line 13a. The standing under a system pressure of the hydraulic system hydraulic hose 13 is via the switching valve 23 and the first hydraulic line 13 a to the cylinder chamber 14 d and also to the

Bar room 14c connected. In the cylinder chamber 14d is in the usual way, the effective pressure surface on the piston 14e greater than the opposite effective pressure surface in the rod space 14c, which is reduced by the mounting surface of the cylinder rod 14b, so that consequently piston 14e moves to the right or the piston rod 14b slowly extends. Here, the cylinder space 14d is filled with hydraulic fluid and hydraulic fluid from the rod space 14c flows out. Overall, this results in a teetering of the main boom extension 5 by a small angle, in particular less than 10 °, preferably less than 5 °, particularly preferably less than 2 °, out of the upright position. This small Abwippbewegung is sufficient so that the rocking cylinder 14 is clearly loaded with a larger proportion of the weight of the main boom extension 5.

For further luffing of the main boom extension 5, the changeover valve 23 is moved to the second position, which is shown in the schematic hydraulic circuit diagram in Figure 4b. Here, the main boom extension 5 is over her Dead weight or about a possible load on the main boom extension 5 further abgegewippt. The switching valve 23 connects in the second position, the bladder accumulator 22 with the cylinder chamber 14 d, so that hydraulic fluid speed from the bladder accumulator 22 flows into the cylinder chamber 14 d. The in the

Rod chamber 14 c located hydraulic fluid flows out of the rod chamber 14 c out in the flow direction> via the valve 17 in the direction of the uppercarriage 3 or container 21.

A schematic hydraulic circuit diagram for the opposite process, namely a rocking of the main boom extension 5, is shown in Figure 4c. Here, the rod space 14c is acted upon by the hydraulic hose 13 and the switching valve 23 in the third position in the flow direction <with hydraulic fluid. In this third position of the switching valve 23, the rocking cylinder 14 operates against the own weight of the main boom extension 5. Also, hydraulic fluid flows from the cylinder chamber 14 d into the bladder accumulator 22.

FIG. 4d shows a schematic hydraulic circuit diagram for the end position after the main boom extension 5 has been rocked up. Cylinder space 14d and rod space 14c are not connected to the hydraulic hose 13 and the rocking cylinder 14 thus blocked. The changeover valve 23 connects the bladder accumulator 22 with the hydraulic hose 13. From the full bladder accumulator 22, only the amount of hydraulic fluid in the flow direction> is discharged in the direction of the container 21, which there due to the supply of hydraulic fluid shown in Figure 4a for the first luffing of the main boom extension 5 additionally is available.

It can be seen from FIGS. 4b and 4c that in the second or third position of the changeover valve 23 the hydraulic fluid between the bladder accumulator 22 and the cylinder chamber 14d is only exchanged.

Alternatively, it is possible in a position, not shown, of the switching valve 23, for bending the main boom extension 5 by a small angle from a steep position, in particular the 0 ° -Steliung out, only the cylinder chamber 14 d to connect the hydraulic hose 13, or the hydraulic line 13 a , The rod space 14c is connected to the bladder accumulator 22 in this embodiment. The hydraulic hose 13 is under a system pressure of the hydraulic system connected via the switching valve 23 and the first hydraulic line 13a to the cylinder chamber 14d. Here, the cylinder chamber 14d is filled with hydraulic fluid and hydraulic fluid flows from the rod chamber 14c out into the bladder accumulator 22. Overall, this results in a lurching of the main boom extension 5 by a small angle, in particular less than 10 °, preferably less than 5 °, particularly preferably less than 2 °, out of the upright position. This small Abwippbewegung is sufficient so that the rocking cylinder 14 is clearly loaded with a larger proportion of the weight of the main boom extension 5.

In the further course of the luffing and later Aufwippens the switching valve 23 is switched in an analogous manner to the positions shown in Figures 4b to 4d.

Furthermore, the rocker cylinder 14 according to the invention can also be used for equipping the vehicle crane 1 in a non-illustrated embodiment with a suitably adapted changeover valve 23. When fitting the vehicle crane 1, the luffing cylinder 14 executes only small aligning movements, in particular in the range from 0 to 100 mm, preferably from 0 to 50 mm, particularly preferably from 0 to 5 mm, without force. Without force in the present case means that

Piston rod 14b or the housing of the rocking cylinder 14 is not hinged to the main boom extension 5 or at the foot of Hauptauslegerverlängerung 5a, but is free to allow alignment of the rocking cylinder 14 prior to bolting with the main boom extension 5a. In order to extend or retract the piston rod 14b, the cylinder space 14d or the rod space 14c via the switching valve 23 with the

Hydraulic hose 13 is brought into communication and acted upon with hydraulic fluid over it. The rod space 14c or cylinder chamber 14d filled with hydraulic fluid is connected to the bladder accumulator 22 via the reversing valve, so that the hydraulic fluid displaced from the rod chamber 14c or cylinder chamber 14d can flow into the bladder accumulator 22. The

Bladder accumulator 22 thus replaces the non-existent recirculating hydraulic line to a limited extent. Excess hydraulic fluid in the bladder accumulator 22 can via a suitable position of the switching valve 23, which the

Bladder accumulator 22 connects to the hydraulic hose 13, via the hydraulic hose 13 to the container 21 to be drained.

LIST OF REFERENCE NUMBERS

1 mobile crane

2 undercarriage

3 superstructure

4 main boom

4a head of the main boom

5 main boom extension

5a foot of the main boom extension

6 basic box

7 first telescopic shot

8 second telescopic shot

9 third telescopic shot

10th telescopic shot

12 hose drum

13 hydraulic hose

13a first hydraulic line

13b second hydraulic line

14 rocker cylinders

14a housing

14b piston rod

14c pole space

14d cylinder space

14e piston

15 hose guide

16 erection cylinders

17 valve

18 gas storage

19 pump

20 control valve

21 containers

22 bubble memory

23 changeover valve A rocking axis D rotation axis

Z section

w rocking angle

I filed position

II upright position

> Flow direction of the hydraulic fluid to the tank (right)

<Flow direction of the hydraulic fluid from the pump (left)

Claims

claims

1. vehicle crane (1) with a main boom (4) and with a on the main boom (4) articulated and by means of at least one rocking cylinder (14) tiltable

Main boom extension (5), characterized in that the luffing cylinder (14) is connected to a hydraulic hose (13) in such a way that the hydraulic fluid either flows to the luffing cylinder (14) or flows away from the luffing cylinder (14) Rocker cylinder (14) is connected to the hydraulic hose (13) with a single flow channel for supplying hydraulic fluid and the hydraulic hose (13) along the main boom (4) is guided.

2. Vehicle crane (1) according to claim 1, characterized in that the

Hydraulic hose (13) has a round cross-section.

3. Vehicle crane (1) according to claim 1 or 2, characterized in that the

Rocker cylinder (14) has a rod space (14c) and a cylinder space (14d), the rod space (14c) or cylinder space (14d) is connected to the hydraulic hose (13) and the not connected to the hydraulic hose (13) cylinder space (14d) or Rod space (14c) is connected to the atmosphere without pressure.

4. Vehicle crane (1) according to one of claims 1 or 2, characterized in that the luffing cylinder (14) has a rod space (14c) and a cylinder space (14d), the rod space (14c) or cylinder space (14d) with the hydraulic hose (14). 13) and which is not connected to the hydraulic hose (13)

Cylinder space (14 d) or rod space (14 c) with a pressure medium, preferably with a gas, particularly preferably with nitrogen, is filled.

5. Vehicle crane (1) according to one of the preceding claims, characterized in that the rocking cylinder (14) is associated with a valve (17) via which an outflow of hydraulic fluid from the rocking cylinder (14) is controllable.

6. Vehicle crane (1) according to one of the preceding claims, characterized in that the rocking cylinder (14) is designed as a pull cylinder or as a pressure cylinder.

7. Vehicle crane (1) according to one of the preceding claims, characterized in that the rocking cylinder (14) is acting on one side.

8. Vehicle crane (1) according to claim 1 or 2, characterized in that the luffing cylinder (14) has a rod space (14c) and a cylinder space (14d), the rod space (14c) and the cylinder space (14d) with the hydraulic hose (13 ) are connected via a switching valve (23) and the cylinder space (14d) via the switching valve (23) with a bladder accumulator (22) can be brought into connection. 9. A vehicle crane (1) according to any one of the preceding claims, characterized in that the main boom (4) is telescopic and from a base box (6) and further arranged therein, eintelekopierbaren and Telescopschüssen (7, 8,

9, 10), and the hydraulic hose (13) during the on and

Austeleskopierens of the main boom (4) of a hose reel (12) unwound or can be wound on this.

10. Vehicle crane (1) according to claim 9, characterized in that the hydraulic hose (13) in several layers on the hose reel (12) nebenei- nander and one above the other is wound up.

1 1. A vehicle crane (1) according to claim 9 or 10, characterized in that the hose drum (12) on the base box (6), is arranged.

12. Vehicle crane (1) according to one of the preceding claims, characterized in that the vehicle crane (1) has an undercarriage (1) and a rotatably mounted thereon superstructure (3).