Mobile Crane And Placement Device For Same

Abstract

The invention relates to a mobile crane, that comprises a mobile undercarriage and a superstructure rotatably supported on the undercarriage and having a boom and a ballasting device. The ballasting device picks up or places down one or more counterweight elements by means of a hoisting device. In accordance with the invention, a placement device is provided that is connected to the undercarriage and comprises at least one movable placement part that is movable from a travel position into a placement position and vice versa. In this respect, the travel position is characterized in that the length of the undercarriage is reduced, and the crane is travelable on the construction site, whereas the placement position is characterized in that counterweight elements can be placed on the placement part by means of the ballasting device and the length of the undercarriage is increased in comparison with the travel position.

Claims

1. A mobile crane, comprising a mobile undercarriage and a superstructure rotatably supported thereon and having a boom and a ballasting device, wherein the ballasting device is adapted to take up or place down one or more counterweight elements by means of a hoisting device, wherein a placement device connected to the undercarriage and having at least one movable placement part that is movable from a travel position reducing the length of the undercarriage into a placement position which increases the length of the undercarriage and in which counterweight elements can be placed on the placement part by means of the ballasting device, and vice versa.

2. A crane in accordance with claim 1, wherein the placement device is adapted to remain at the undercarriage during crane operation and/or during the traveling of the crane.

3. A crane in accordance with claim 1, wherein the placement part extends substantially transversely to the longitudinal axis of the undercarriage in the travel position and is outwardly pivotable into the placement position in which the placement part extends substantially in parallel with the longitudinal axis of the undercarriage, with the placement part preferably having one or more placement areas at an upper side on which counterweight elements can be placed.

4. A crane in accordance with claim 3, wherein the placement part is pivotably supported about a vertical pivot axle, with the pivot axle being off center with respect to the longitudinal axis of the undercarriage, including laterally at the placement device.

5. A crane in accordance with claim 1, wherein the pivotable support of the placement part takes place via two separate pivot bearings that are arranged above one another and are designed differently.

6. A crane in accordance with claim 1, wherein a lower pivot bearing is thicker than an upper pivot bearing, with the upper pivot bearing being adapted to take up predominantly horizontal forces and/or the lower pivot bearing being adapted to take up horizontal and vertical forces, including the weight force of the counterweight elements placed on the placement part.

7. A crane in accordance with claim 5, wherein the placement part has locking means by means of which it can be locked in the travel position and in the placement position respectively.

8. A crane in accordance with claim 7, wherein the locking means are formed at one of the pivot bearings, including at an upper pivot bearing, and comprise or represent cutouts into which a locking element, including a locking bolt, can be pushed in the corresponding position of the placement part.

9. A crane in accordance with claim 3, wherein the placement device comprises a first placement part and a second placement part on which counterweight elements can be placed in the placement position, with the placement parts preferably being pivotable about vertical pivot axles that are spaced apart from one another and that are located laterally on oppositely disposed sides of the placement device.

10. A crane in accordance with claim 9, wherein the placement device comprises two parallel frame parts, including frame plates, to whose front sides the placement parts are connected in an articulated manner, with the frame parts being directly connected to the undercarriage.

11. A crane in accordance with claim 10, wherein the frame parts have different lengths in the direction of the longitudinal axis of the undercarriage and the pivot axles of the placement parts have different distances from the undercarriage, with the placement parts being plate-like and being respectively aligned in parallel with one another in the transport position and placement position.

12. A crane in accordance with claim 1, wherein the placement device comprises at least one centering element that is configured to cooperate with a corresponding counter-centering element at the lower side of the counterweight element for the fine positioning of a counterweight element to be placed on the placement device, with the at least one centering element being arranged at an upper side of the placement device and/or being configured as an upwardly protruding projection.

13. A crane in accordance with claim 10, wherein at least two centering elements are provided, with at least one centering element being fixedly connected to each of the frame parts.

14. A crane in accordance with claim 1, wherein the placement device comprises a ballast element and acts as central ballast, with the placement device comprising two parallel frame parts, to whose front sides a respective placement part is connected in an articulated manner and with the ballast element being arranged between the frame parts.

15. A placement device for a crane in accordance with claim 1.

16. A crane in accordance with claim 1, wherein the crane is a crawler crane.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0049] Further features, details, and advantages of the invention result from the embodiment explained in the following with reference to the Figures. There are shown:

[0050] FIG. 1: a crawler crane known from the prior art in a side view;

[0051] FIGS. 2-3: the crane in accordance with the invention in accordance with a preferred embodiment as a crawler crane in a side view;

[0052] FIG. 4: a perspective view of the placement device in accordance with the invention in accordance with the preferred embodiment in the travel position;

[0053] FIG. 5: the placement device in accordance with FIG. 4 in the placement position;

[0054] FIG. 6: a plan view of the undercarriage with the placement device in accordance with the invention in the travel position;

[0055] FIG. 7: a section through one of the frame parts of the placement device in a perspective view;

[0056] FIG. 8: the placement device in accordance with the invention in the placement position with two counterweight elements placed thereon in a perspective sectional view through the counterweight elements; and

[0057] FIG. 9: an enlarged view of the crane in accordance with FIG. 3 in the region of the placement device.

DETAILED DESCRIPTION

[0058] A crawler crane 1 of the category such as is known from DE 20 2008 008 595 U1 is shown in FIG. 1. The crane 1 has an undercarriage 12 with a crawler chassis comprising two crawler carriers 18. A superstructure 14 is rotatably supported on the undercarriage 12 about a vertical axis of rotation 13 via a rotational connection 7 (see FIG. 6). The superstructure 14 comprises a boom 6 (here: a telescopic boom) luffable about a horizontal axis and a ballasting device 20.

[0059] Plate-like counterweight elements 22, 22′ can be taken up and placed down by means of the ballasting device 20 at the superstructure 14 in a manner known per se by means of a hoisting device 24 (i.e. at the superstructure 14 to form the superstructure ballast). As can be recognized in FIG. 9, the hoisting device 24 comprises one or more hydraulic ballast cylinders 24 that are arranged in the ballasting device 20 and whose piston rods can be extended downwardly. In a manner known per se, the piston rods move (with a correct positioning of the superstructure 14 relative to the counterweight elements 22, 22′) through corresponding recesses in the counterweight plates 22, 22′ and can be locked or brought into engagement therewith. This can take place, for example, in accordance with DE 296 21 600 U1, but also in any different manner The counterweight plates 22, 22′ are raised to the ballast mount of the ballasting device 20 and thus to the superstructure 14 by retracting the piston rods of the ballast cylinders.

[0060] Provision can be made in this respect that the counterweight plates 22, 22′ can be connected to the ballasting device 20 or to the ballast mount. Provision can alternatively or additionally be made that the pressure in the ballast cylinders is maintained, for example by corresponding hydraulic reservoirs, such that the counterweight plates 22, 22′ remain at the superstructure 14.

[0061] With the crane 1 shown in FIG. 1, a cantilever frame 3 is fastened to the undercarriage 12 (more precisely to the center frame part 6 of the undercarriage 12, cf. FIG. 6) between the crawler carriers 18, with said counterweight plates 22, 22′ being placeable on said undercarriage 12. The cantilever frame 3 has a suitable placement area 4 for supporting the counterweight plates 22, 22′ at the upper side and has one or more centering element 5 that move the counterweight plates 22, 22′ into a defined position with respect to the axis of rotation 13 of the superstructure 14. This cantilever frame 3 can, however, only be dismantled from the undercarriage 12 in a complicated manner and therefore remains at the undercarriage 12 as a rule. It is thereby extended in the longitudinal direction, which has a negative effect on the maneuverability of the crane 1.

[0062] For this reason, with the crane 10 in accordance with the invention, that is shown in a side view in FIGS. 2-3, a foldable placement device 30 is provided instead of the cantilever frame 3 (but at the same position, i.e. between the crawler carriers 18), said placement device 30 being able to be moved into a placement position (as shown in FIGS. 2-3) that increases the length of the undercarriage 12 for the support of the counterweight plates 22, 22′ and can be moved into a travel position reducing the undercarriage length to travel the crane 10. The device in accordance with the invention thereby takes up the advantages of DE 20 2008 008 595 U1 without having to achieve this by a reduction in the maneuverability of the crane 10.

[0063] FIG. 2 shows the crane 10 in accordance with the invention with the placement device 30 in the placement position, with the counterweight plates 22, 22′ being raised by the ballast cylinders 24. The counterweight plates 22, 22′ are in contrast placed on the placement device 30 in FIG. 3. An enlarged view of the placed down weight plates 22, 22′ in accordance with FIG. 3 is shown in FIG. 9.

[0064] FIG. 4 (in the travel position here) and FIG. 5 (in the placement position here) show a perspective view of the placement device 30 in accordance with the invention in accordance with a preferred embodiment. A plan view of the undercarriage 12, more precisely its center frame part 6 with a placement device 30 fastened thereto can be seen in FIG. 6.

[0065] The placement device 30 in accordance with the invention is at the same time configured as central ballast for the crane 10 in the embodiment shown here and has a corresponding ballast element 36. The placement device 30 comprises plate-like frame parts 33, 34, that can also be called side walls 33, 34 of the ballast element 36, at the side, that is at the sides of the ballast element 36 facing the crawler carriers 18. These side walls 33, 34 are formed as comparatively thick to be able to reliably take up the forces that occur and to be able to transfer them to the center frame part 6 of the undercarriage 12. The side walls 33, 34 have connection means, via which the placement device 30 is releasably connectable to corresponding connection means 8 of the center frame part 6, at the ends or front sides facing the center frame part 6.

[0066] The ballast element 36 can be fixedly, i.e. non-releasably, or releasably connected to the frame parts 33, 34, for example by means of screws and/or bolts. The ballast element 36 can be integrated in the bearing structure of the placement device 30.

[0067] The placement device 30 in accordance with the invention can be simply retrofitted in existing cranes by the linking of the function or assembly of “foldable counterweight placement area” with the central ballast. The reworked central ballast is attached to the center frame part 6 of the crawler crane 10 for this purpose.

[0068] In an alternative embodiment, the placement parts 31, 32 could be directly connected in an articulated manner to the center frame part 6 of the undercarriage 12 without the frame parts 33, 34, that is in particular the placement device 30 can be attached to the undercarriage 12 without a ballast element 36 and side walls 33, 34.

[0069] As can be seen in FIG. 6, connection means 8 are likewise provided at the oppositely disposed side of the center frame part 6 to optionally be able to fasten a further central ballast or a second placement device 30 (or to be able to fasten a single placement device 30 as required on the one or other side of the center frame part 6).

[0070] Alternatively, the placement device 30 could also be provided and/or be fixedly (i.e. non-releasably) fastened to the center frame part without a ballast element 36.

[0071] At the ends of the side walls 33, 34 (in the embodiment shown here, they are the ends disposed opposite the connection means to the center frame part 6) remote from the axis of rotation 13 of the superstructure 14, plate-like placement parts 31, 32 are pivotably supported that can also be called folding metal sheets 31, 32. For this purpose, each side wall 33, 34 has a pivot axle divided into two (with an upper and lower pivot axle) that is integrated into the metal sheet of the respective side wall 33, 34. The corresponding support parts can be low friction bronze bushes.

[0072] To reduce the weight and to optimally introduce the forces into the side walls 33, 34, the placement parts 31, 32 in the present case are shaped more or less as triangular or have a chamfered side, with other shapes naturally also being conceivable, for example a rectangular shape.

[0073] In the travel position, the placement parts 31, 32 are folded in and contact the ballast element 36 (cf. FIGS. 4 and 6). For this purpose, the side walls 33, 34 project beyond the ballast element 36 in the longitudinal direction of the undercarriage so that the placement parts 31, 32 can be folded inwardly. In the travel position, the surfaces of the placement parts 31, 32 face one another and toward the front side of the ballast element 36. The length of the placement device 30 (and thus of the total undercarriage 12) is minimized in the travel position and is only insignificantly larger than if the placement parts 31, 32 were not provided.

[0074] In the placement position (cf. FIGS. 5 and 7), the placement parts 31, 32 are folded outwardly by 90° about their pivot axles so that they are aligned in parallel and extend along the longitudinal axis of the undercarriage. This corresponds to the maximum length of the placement device 30 (and of the undercarriage 12).

[0075] The placement parts 31, 32 each have an upper pivot bearing 61 associated with the upper pivot axle and a lower pivot bearing 62 associated with the lower pivot axle. The upper pivot bearing 61 is primarily adapted to take up the horizontal forces. The lower pivot bearing 62 is primarily provided to take up forces in the vertical direction (this is substantially the weight force of the counterweight plates 22, 22′ placed on the placement parts). For this purpose, the lower pivot bearing 62 is thicker/higher than the upper pivot bearing 61. The lower pivot bearing 62 naturally also has to take up the oppositely disposed horizontal forces from the force pair together with the upper pivot bearing 61.

[0076] Alternatively or additionally, the upper and lower pivot axles can be of different thicknesses to be able to ideally take up and introduce the differently acting forces.

[0077] The placement parts 31, 32 can each be locked in the travel and placement positions. For this purpose, in the embodiment shown in the present case, two respective recesses or bolt mounts 71, 32 that act as first and second locking means 71, 72 are formed in the upper pivot bearings 61. A locking bolt 74 is furthermore provided with a handle in each of the two side walls 33, 34, with the locking bolt 74 being pushable into the first bolt mount 71 in the travel position and into the second bolt mount 72 in the placement position to lock the corresponding placement part 31, 32 in this position. The side walls 33, 34 are thick enough to completely receive the locking bolts 74.

[0078] In the embodiment shown here, the locking bolts 74 are manually pushed into the bolt mounts 71, 72. The placement parts 31, 32 are likewise manually pivoted between the travel and placement positions. The locking and/or pivoting can, however, alternatively also take place by corresponding actuators, for example hydraulic cylinders.

[0079] The locked placement position is shown in a sectional view through the left side wall 34 in FIG. 7, with here the locking bolt 74 supported in a vertical bore of the side wall 34 being able to be recognized that extends through the second bolt mount 72 of the left placement part 32 and locks the latter. It is analogous with the right placement part 31. The first bolt mounts 71 are within the outwardly folded placement parts 31, 32 in this position.

[0080] In principle, the bolt mounts 71, 72 could also be formed in the lower pivot bearing 62 and the locking bolts 74 could correspondingly be supported in the lower regions of the side walls 33, 34.

[0081] Both placement parts 31, 32 carry out a pivot movement about their respective pivot axles. Consequently, they cannot be arranged in a common plane in the travel position due to the required distance from the axis of rotation 13 and thus also due to their own required lengths. For this reason, one of the pivot axles of the placement parts 31, 32 has a greater distance from the axis of rotation 13 or from the ballast element 36 than the pivot axle of the other placement part 31 (see FIG. 6). The corresponding placement part 31 is therefore in front of the other placement part 31 viewed from the axis of rotation 13 or from the ballast element 36. To achieve this, the side wall 34 (the left wall in FIG. 6) is longer than the other side wall 33.

[0082] As already stated, the respective side wall 33 and 34 also serves as a mount for the locking bolt 74. To avoid a complex weld construction, the side walls 33, 34 are particularly thick. The bores for the receivers of the locking bolts 74 are thus directly introduced into the metal sheets of the side walls 33, 34 and there is still enough material for a secure connection.

[0083] The total central ballast 30 has a new design in comparison with known cranes to be able to satisfy the set tasks. This includes the thick side walls 33, 34 and the thick connection elements 8 to the undercarriage 12 or center frame part 6, the different designs of the side walls 33, 34, the placement parts 31, 32 connected in an articulated manner, and the locking mechanism 71, 72, 74.

[0084] An operating error must also be taken into account here. The counterweight mount device or the ballasting device 20 has thick ballast cylinders 24. If the superstructure 14 is not in the correct position to travel into the cutouts provided for this purpose in the counterweight plates 22, 22′, the ballast cylinders 24 press onto the counterweight plates 22, 22′ and increase the load on all the components. The placement device 30 is adapted to such a case and all the major elements are correspondingly dimensioned.

[0085] The placement parts 31, 32 have placement areas 40, 41 on the upper sides that are contacted by the lowest placed down counterweight plate 22′ or on which the latter is supported. A defined contact surface thereby results for the counterweight. Each placement part 31, 32 has a rear placement area 40 in the region of the pivot axle and a front placement area 41 at the oppositely disposed end (in a plan view). The rear placement area 40 of the placement part 32, whose pivot axle is further spaced apart (at the left in FIG. 5) from the axis of rotation 13 of the superstructure is shorter than the rear placement area 40 of the other placement part to compensate the offset of the pivot axles. This is, however, not compulsory. More than two placement areas per placement part and/or a different positioning are naturally furthermore also conceivable. The spacing of the placement areas 40, 41 per placement part 31, 32 is selected such that a secure contact of the counterweight plates 22, 22′ is ensured before their installation on the superstructure 14.

[0086] Two centering elements 50 are provided to precisely position the counterweight plates 22, 22′ or to exactly fix their alignment and position relative to the axis of rotation 13 of the superstructure 14 and thus to enable a smooth engagement of the ballast cylinders 24 in the corresponding cutouts of the counterweight plates 22, 22′

[0087] The centering elements 50 are outwardly attached to the side walls 33, 34, and indeed in the region of the locking bolts 74 (cf. FIGS. 4-5). The centering elements 50 themselves require a high accuracy in their location with respect to the axis of rotation 13 of the superstructure 14. An attachment to the pivotable placement parts 31, 32 would consequently not be constructive. The centering elements 50 are therefore separate from the placement parts 31, 32 and are instead fixedly connected or welded to the side walls 33, 34. This solution additionally brings about the advantage that the forces that occur on the alignment of the counterweight plates 22, 22′ are not to be conducted via the pivot bearings 61, 62. The centering elements 50 can furthermore not sensibly be attached to the placement parts 31, 32 due to their space requirement.

[0088] The centering elements 50 are arranged at upper sides of fastening pieces 52 laterally welded to the side walls 33, 34 and project upwardly. In the embodiment shown here, the centering elements 50 are substantially of cylindrical shape and have an introduction chamfer (i.e. the upper edge is chamfered to enable an easier threading), with other shapes also being conceivable. The lowest counterweight plates 22,' has complementary recesses or counter-bores 26 at the corresponding points at the lower side and the centering elements 50 travel into them on the placing down of the counterweight plates 22′ (cf. the sectional view of FIG. 8).

[0089] If the crane operator stacks the counterweight plates 22, 22′ on the undercarriage 12 using his own boom 16, he lowers the first counterweight plate 22′ in its approximate position. In this respect, the recesses 26 in the counterweight plate 22′ contact the centering elements 50 and the counterweight plate 22′ is aligned in its assembly position. The counterweight plate 22′ lies on the placement areas 40, 41 by a further lowering of it. Further counterweight plates 22 are stacked in an analogous manner The lowest counterweight plate 22′ can also have further connection means known from the prior art for the connection to the superstructure 14 (cf. FIG. 9). The further counterweight plates 22 can in particular have recesses through which connection elements of the lowest counterweight plate 22′ project in the stacked state and that serve the fastening of the ballast stack 22, 22′ on the superstructure 14.

[0090] The further counterweight plates 22′ can be formed identically or differently.

[0091] Instead of continuous side walls 33, 34 or metal side plates, other designs, e.g. lattice-like or checkered frame structures, can also be used. This also applies alternatively or additionally to the placement parts 31, 32.

REFERENCE NUMERAL LIST

[0092] 1 crawler crane (prior art) [0093] 3 cantilever frame [0094] 4 placement area [0095] 5 centering element [0096] 6 center frame part [0097] 7 rotary connection [0098] 8 connection means [0099] 10 mobile crane (crawler crane) [0100] 12 undercarriage [0101] 13 axis of rotation [0102] 14 superstructure [0103] 16 boom [0104] 18 crawler chassis [0105] 20 ballasting device [0106] 22 counterweight element [0107] 22′ lowest counterweight element [0108] 24 hoisting device (ballast cylinder) [0109] 26 centering counter-element (recess) [0110] 30 placement device [0111] 31 first placement part [0112] 32 second placement part [0113] 33 first frame part (side wall) [0114] 34 second frame part (side wall) [0115] 36 ballast element [0116] 40 rear placement area [0117] 41 front placement area [0118] 50 centering element [0119] 52 fastening piece [0120] 61 upper pivot bearing [0121] 62 lower pivot bearing [0122] 71 first locking means (bolt mount) [0123] 72 second locking means (bolt mount) [0124] 74 locking element (locking bolt)