Mobile crane with counterweight device, counterweight device and method for assembling such a device

Abstract

Mobile crane (1) comprising a mobile undercarriage (2), a superstructure (4) rotatably mounted on the undercarriage (2), and a counterweight device (10) connectable to the superstructure (4) with a counterweight base plate (20), a support plate (40), and at least two suspension weights (50) detachably connectable to the support plate (40), wherein the support plate (40) can be placed on the counterweight base plate (20) and comprises first connecting elements (41) for establishing a first suspension connection (100) with first connecting elements (51) of the suspension weights (50), characterized in that the support plate (40) and the suspension weights (50) are designed as a jointly liftable assembly unit (11) and the suspension weights (50) have lifting devices (58) for lifting the entire assembly unit (11).wherein the support plate (40) comprises second connecting elements (42) for making a second connection (200) with second connecting elements (52) of the suspension weights (50), which is designed to block the first suspension connection (100) from loosening when the assembly unit (11) is lifted via the suspension weights (50).

Description

[0001] The present invention relates to a mobile crane according to the preamble of claim 1.

[0002] Mobile cranes typically have an undercarriage with wheeled or crawler tracks, a superstructure mounted on the undercarriage for rotation around a vertical axis, a boom (e.g., a telescopic or lattice boom) pivotably attached to the superstructure, and a counterweight device, also known as superstructure ballast. The counterweight applies a countertorque to the load moment via a lever arm in any position of the superstructure and therefore rotates with the superstructure.

[0003] An embodiment known from the prior art is disclosed, for example, in DE 20 2022 105 980 U1.

[0004] While smaller mobile cranes, often known as taxi cranes, carry all the equipment needed for use on the construction site, even on public roads, larger mobile cranes are not capable of this. Therefore, crane components, especially the counterweight, must be fully or partially dismantled for transport on public roads and reassembled on-site. With crawler cranes, the counterweight must also typically be dismantled for transport and reassembled on the superstructure at the job site.

[0005] It is therefore known from the prior art to provide a support plate or a counterweight base plate with coupling elements for detachable connection to the superstructure, on which multiple counterweight elements can be stacked. The superstructure is provided with a ballasting device at the rear, which is capable of picking up the counterweight device, comprising the counterweight base plate and the counterweight elements stacked on it, from the ground or from a storage area on the undercarriage, and lifting it onto the superstructure for assembly. For disassembly, the counterweight base plate with the counterweight elements can be placed back on the ground or the undercarriage.For this purpose, the ballasting device typically comprises one or more hydraulic ballasting cylinders that extend downwards, engage with the coupling elements of the counterweight device, and retract, lifting the counterweight device onto the superstructure. Counterweight devices with ballasting cylinders that extend upwards are also known.

[0006] Counterweights are often filled box structures. A box contains all the necessary connecting elements and internal bracing to absorb the forces. In addition, suspension weights are known that have receptacles for hooking and bolting, and can be suspended, in particular, laterally from central counterweight plates. An example of such suspension weights for use in counterweight devices of mobile cranes is known from DE 10 2020 123 821 B3. Such suspension weights can be suspended in one or two lifts per side and have corresponding lifting devices by which they can be picked up and lifted via a chain or rope.

[0007] Such suspension weights have the advantage that they do not increase the turning radius of the superstructure on the construction site and, thanks to their additional mass, improve the stability moment when the load is attached to the boom and prevent tipping in the load direction. A disadvantage, however, is the additional number of lifts required to bring the individual suspension weights into a setup position. The setup position is understood to be a position in which the ballasting device of the mobile crane can reach the counterweight device in its final state and mount it on the superstructure in the rear area, i.e. on the side of the superstructure opposite the boom. Each additional lift of counterweight elements takes time and increases the setup time for the counterweight device or the time required to bring the mobile crane into an operational state.In addition, each additional lift and the attachment of the suspension weights entails an additional risk of an avoidable work step.

[0008] The present invention is therefore based on the object of providing a counterweight device for generic mobile cranes which can be set up quickly and safely.

[0009] According to the invention, this object is achieved by a mobile crane having the features of claim 1, a counterweight device having the features of claim 13, and an assembly method having the features of claim 14. Advantageous embodiments of the invention emerge from the subclaims and the following description.

[0010] Accordingly, on the one hand, a mobile crane is proposed which comprises a mobile undercarriage, an uppercarriage mounted so as to rotate on the undercarriage, and a counterweight device which can be coupled to the uppercarriage. Furthermore, a boom, for example a telescopic boom, is pivotably connected to the uppercarriage. The counterweight device comprises a counterweight baseplate, a carrier plate, and at least two suspension weights which can be detachably connected to the carrier plate. The carrier plate can be placed either directly, i.e. directly, on the counterweight baseplate, or it can be placed indirectly on the counterweight baseplate (i.e. in this case, further counterweight elements can be stacked on the counterweight baseplate, on which the carrier plate can in turn be placed). The carrier plate further comprises first connecting elements for establishing a first suspension connection with first connecting elements of the suspension weights.

[0011] According to the invention, the support plate and the suspension weights are designed as a jointly liftable assembly unit (hereinafter also referred to as the first or upper assembly unit). The support plate and the suspension weights therefore do not have to be lifted individually and assembled on the mobile crane, but can be transported in the assembled state (for example, on a separate transport vehicle) and then lifted together in the assembled state and placed on the counterweight base plate. This eliminates the need for additional lifting of the suspension weights on the construction site and the need to hook them into the corresponding suspension connections on site, which significantly reduces setup time and increases safety during setup.

[0012] The assembly unit can be assembled once before use on the construction site and does not need to be disassembled during transport or when setting up the mobile crane. The assembly unit can remain assembled until the carrier plate is to be used without the counterweights for a specific application, for example. For this purpose, the carrier plate is preferably also equipped with appropriate lifting devices so that it can be lifted individually.

[0013] To ensure that the support plate can be lifted together with the suspension weights, further precautions must be taken. With standard suspension connections, such as those described in DE 10 2020 123 821 B3, there would otherwise be a risk that one of the suspension weights could detach from the support plate when lifting the assembly unit.

[0014] For this reason, according to the invention, the support plate and the suspension weights comprise not only the first connecting means for forming the suspension connection, but also second connecting means that establish a second connection, in particular after the first suspension connection has been established. Furthermore, according to the invention, the assembly unit can be lifted via the lateral suspension weights. For this purpose, the suspension weights have corresponding attachment means to which a rope or chain of a lifting device can be attached. The second connecting means are designed such that, together with the first connecting means, they can transmit the high forces that arise during the lift due to the weight of the support plate.

[0015] This allows the assembly unit to be lifted using the suspension weights, particularly via the boom of the mobile crane itself, and the counterweight device to be assembled or set up in such a way that it can then be lifted onto the superstructure by a ballasting device.

[0016] Furthermore, the second connection serves to secure the first suspension connection. The second connection is therefore designed according to the invention such that when the assembly unit is lifted via the suspension weights, release of the first suspension connection of the respective suspension weight is blocked or prevented. This is a factor that significantly increases safety not only when moving the assembly unit, but also during crane operation when the counterweight device is attached to the superstructure. In this case, it is also important to take potential problem situations into account. These could be, for example, the load breaking off at the boom, which typically releases very large forces. In this case, too, no avoidable risks must occur. These forces can accelerate even very heavy elements, such as the attached suspension weights, upwards against their gravity and detach them from their abutments or connections.The safety function of the second connection prevents the suspension connections from coming loose even in such problematic cases.

[0017] The counterweight base plate and / or the support plate and / or the suspension weights can be made of grey cast iron or designed as a filled box construction.

[0018] In one possible embodiment, the superstructure comprises a ballasting device configured to lift the counterweight device from a storage area of ​​the undercarriage and to deposit it thereon. The ballasting device preferably comprises at least one hydraulic ballasting cylinder, which can be extended downwards in particular toward the mounted counterweight device and coupled thereto. By subsequently retracting the at least one ballasting cylinder, the counterweight device can be lifted from the storage area on the undercarriage and brought toward the superstructure, where the counterweight device can be connected to the superstructure, for example, via bolt connections.

[0019] The ballasting device preferably comprises a ballast frame that can be connected (in particular bolted) to the superstructure and is movable by the ballasting cylinder(s). Alternatively or additionally, the ballast frame can comprise a winch structure that can be releasably attached to the ballast frame, for example. The ballast frame can be releasably connected to the frame structure of the superstructure via appropriate fastening elements such as bolt receptacles and bolts, so that it can also be removed from the superstructure for transport.

[0020] In a further possible embodiment, the counterweight device comprises at least one coupling element extending substantially perpendicular to the counterweight base plate and connected thereto for lifting and coupling the counterweight device to the superstructure. The carrier plate preferably comprises at least one recess through which the at least one coupling element protrudes when laid down. When placed on the counterweight base plate (or another counterweight element stacked thereon), the carrier plate is thus "threaded" onto the at least one coupling element. The at least one coupling element represents, in particular, a tension element and fastening element for the entire counterweight device in one, which reduces the number of components, facilitates operation and assembly, and ensures a stable connection between the various components.The at least one coupling element can be formed in one piece. This eliminates the need for complex welded connections with other components, simplifying the manufacturing process.

[0021] In a further possible embodiment, the at least one coupling element has a coupling section at an end opposite the counterweight base plate, via which a coupling to the ballasting device, in particular a ballasting cylinder, can be established. Said ballasting cylinder can have a piston rod that can be extended downward from the ballasting device and coupled to the coupling section of the coupling element. Preferably, two or more ballasting cylinders and a corresponding number of coupling elements are provided.

[0022] In a further possible embodiment, the coupling section comprises a receptacle into which a coupling piece of a ballasting cylinder can be inserted, in particular by rotating the superstructure about its axis of rotation. The coupling piece can be part of the piston rod of the ballasting cylinder or a component connected to it. The recess of the coupling section can be designed in a conventional manner such that it allows lateral insertion of the ballasting cylinder (e.g., following a circular movement) and, in the coupled state, positively blocks movement of the ballasting cylinder out of the recess in the vertical direction.

[0023] In a further possible embodiment, the counterweight device comprises a further counterweight element that can be stacked on the counterweight base plate and has at least one recess through which the aforementioned at least one coupling element protrudes when stored. The further counterweight element is arranged between the counterweight base plate and the carrier plate in the assembled state. If only a single further counterweight element is present, the carrier plate preferably rests directly on it. If several further counterweight elements are present, the carrier plate rests in particular on the uppermost or on the at least one coupling element.

[0024] Preferably, the counterweight base plate and the at least one additional counterweight element also form a jointly liftable assembly unit (hereinafter also referred to as the second or lower assembly unit). This further reduces the number of lifts required for setup. This assembly unit can, for example, be transported separately from the mobile crane and lifted together onto a storage area on the undercarriage of the mobile crane for setup, for example, using the boom of the mobile crane itself.

[0025] The various assembly units can be designed with a total weight that allows them to be transported cost-effectively on public roads. For example, one or both assembly units can weigh approximately 20 tons (or less), although other values ​​are of course possible depending on the country and requirements.

[0026] In a further possible embodiment, the at least one coupling element comprises a centering means by means of which the counterweight device can be positioned in an installation position on the superstructure. The centering means cooperates in particular with a counter-centering means on the superstructure and ensures automatic positioning of the counterweight device during lifting onto the superstructure. Centering the counterweight device in a designated installation position on the superstructure facilitates its installation.

[0027] The superstructure preferably has a corresponding counter-centering means which is designed to automatically position the counterweight device in an assembly position when the counterweight device is lifted by interacting with the centering means of the coupling element, in which position it can be connected to the superstructure, in particular to the aforementioned ballasting device. The centering means is preferably designed as an element extending substantially in the longitudinal direction of the coupling element, e.g. as a projection. The counter-centering means accordingly forms a recess into which the centering means moves when the counterweight device is lifted. However, the reverse case (centering means as a recess and counter-centering means as a projection or similar projecting downwards from the superstructure) is also conceivable. The centering means preferably comprises at least one beveled surface or chamfer, i.e.To facilitate the interlocking of the centering device and counter-centering device, it can have one or more beveled surfaces, for example, in one or two directions. A conical shape with a circumferential chamfer on the centering device or counter-centering device is also possible.

[0028] Alternatively or additionally, the at least one coupling element can comprise a fastening means by which the counterweight device can be detachably connected to the superstructure in an assembly position (in particular the assembly position achieved by the aforementioned pre-centering). Thus, the counterweight device is not held on the superstructure by one or more ballasting cylinders during crane operation, but rather a separate connection is provided, which is established via the fastening means of the at least one coupling element and, in particular, via corresponding connecting means on the superstructure. This allows the counterweight device, including the carrier plate and suspension weights, to be securely and stably attached to the superstructure, thus relieving the load on the ballasting cylinders.

[0029] In a further possible embodiment, the second connections form axes of rotation for the suspension weights and are designed such that the suspension weights pivot about the axes of rotation relative to the support plate when the assembly unit is lifted. Due to the high weight of the centrally arranged support plate, the laterally arranged suspension weights spread apart laterally by a defined distance when lifted. This rotational or spreading movement is preferably limited by a stop on the first connecting elements. To enable this rotational or spreading movement, the first connecting elements must be designed accordingly and allow a certain degree of mobility even when connected.

[0030] By spreading the weights apart, the distance between the suspension weights increases by a defined distance, so that when spread apart, the mounting unit forms a wider receiving area or recess for the counterweight base plate, making it easier to place it on it. When placed down, the suspension weights are located next to the counterweight base plate and pivot towards it due to their own weight.

[0031] This targeted spreading movement of the suspension weights during lifting facilitates the placement of the assembly unit consisting of the carrier plate and suspension weights on the counterweight base plate (or any additional counterweight elements placed on it).

[0032] In a further possible embodiment, the first connecting elements comprise suspension bolts arranged on the support plate and hook elements arranged on the suspension weights, the latter being hooked into the suspension bolts in order to anchor the suspension weights to the support plate. The hook elements comprise a recess which is open on one side and preferably has a greater width than the suspension bolt received therein in order to enable the aforementioned spreading movement through this defined play. The stop of the first connecting elements which limits the spreading movement is preferably formed by the aforementioned hook elements and suspension bolts. Instead of the previously described hook connection, plug-in bolt connections can also be used.

[0033] Alternatively or additionally, it can be provided that the recesses of the hook elements widen towards their openings, which facilitates the insertion of the suspension bolts.

[0034] In another possible embodiment, the support plate has recesses, particularly on the sides or corners, within which the first and second connecting elements are arranged such that, when viewed from above, they do not protrude beyond the outer contour of the support plate. This does not increase the overall width of the support plate, particularly when used without suspension weights. The recesses can be formed by the surrounding metal sheets of the support plate, if the plate is designed as a filled sheet metal box construction.

[0035] In another possible embodiment, the counterweight device is designed such that, when the support plate is in the lowered state, the associated suspension weights are arranged laterally next to the counterweight base plate. In particular, the suspension weights can have a height that corresponds to the total height of the counterweight package comprising the counterweight base plate, any additional counterweight elements, and the support plate. Of course, it is also possible for the suspension weights to have a lower height or to protrude upwards above the support plate.

[0036] For stable mounting and attachment of the counterweight device to the superstructure, more than one coupling element is preferably provided. In another possible embodiment, the counterweight device therefore comprises at least two coupling elements spaced apart from one another and connected to the counterweight base plate. Exactly two coupling elements can be provided, or more than two coupling elements can be provided. The coupling elements preferably have a flat shape.

[0037] Preferably, the coupling elements are arranged at the same distance from the center of gravity or from a center line of the counterweight base plate (which is preferably aligned parallel to the longitudinal axis of the superstructure). This can result in an overall axially symmetrical arrangement of the counterweight base plate and coupling elements.

[0038] Alternatively or additionally, the coupling elements can be arranged rotated relative to each other (each around a vertical axis), i.e., their coupling sections do not point exactly toward each other. This may be due to the fact that the ballasting cylinders are moved in a circular path by the rotation of the superstructure to establish the coupling with the coupling elements. Preferably, however, the coupling elements are not rotated relative to each other, but arranged parallel to each other. This simplifies the manufacture of the counterweight base plate and also of the counterweight elements that can be stacked on top of it.

[0039] Preferably, the counterweight base plate including the coupling element(s) and / or the carrier plate has a structure that is axially symmetrical to a central axis running through the center of the counterweight device.

[0040] The present invention further relates to a counterweight device for a mobile crane according to the invention. This obviously results in the same advantages and properties as for the mobile crane according to the invention, which is why a repetitive description is omitted. The counterweight device preferably comprises at least one additional counterweight element, which can be placed or stacked on the counterweight base plate. The counterweight element preferably has at least one recess for the passage of the at least one coupling element.

[0041] The invention further relates to a method for mounting the counterweight device according to the invention on the superstructure of a mobile crane according to the invention. The method comprises at least the following steps: - Placing the counterweight base plate on a storage area of ​​the undercarriage, in particular by means of a boom of the mobile crane, - Lifting the assembly unit from the carrier plate and the associated suspension weights using the suspension weights’ lifting gear, - Placing the assembly unit on the counterweight base plate, wherein the assembly unit is placed either directly on the counterweight base plate or on another counterweight element stacked on top of it, - Lifting the entire counterweight device to the superstructure via a ballasting device of the mobile crane, in particular by coupling at least one ballasting cylinder with at least one coupling element connected to the counterweight base plate and projecting through the support plate.

[0042] This obviously results in the same advantages and properties as for the mobile crane according to the invention, which is why a repetitive description is omitted. In particular, reference is made to the possible embodiments and optional features discussed in the context of the mobile crane according to the invention, which apply analogously to the method according to the invention.

[0043] In one possible embodiment of the method, the first and second connections are configured as described above, and the second connecting elements form a rotation axis around which the suspension weights pivot relative to the support plate during lifting. When the mounting unit is lifted, the suspension weights therefore spread apart laterally as described above, so that the mounting unit, in the spread-open state, forms a widened receiving area for the counterweight base plate and can be placed thereon. During lowering, the suspension weights are preferably arranged next to the counterweight base plate and pivot toward it.

[0044] Further features, details, and advantages of the invention will become apparent from the following exemplary embodiments explained with reference to the figures. They show: Fig. 1: the mobile crane according to the invention according to an embodiment in a side view; Fig. 2: the counterweight device according to the invention during setup, viewed from its rear side; Fig. 3: the counterweight device in the erected state, looking at its rear; Fig. 4: the counterweight device in the erected state in a plan view; Fig. 5: an enlarged section of the connection area of ​​a suspension weight in plan view; Fig. 6: the connection area according to Fig. 5 in a side view; and Fig. 7: the equipped counterweight device 10 with the attached assembly unit 11 during lifting by means of sling ropes, viewed from its rear side.

[0045] In the Fig. Figure 1 shows a side view of an embodiment of the mobile crane 1 according to the invention in the form of a crawler crane. The mobile crane 1 has an undercarriage 2 with a crawler track and a superstructure 4 mounted on the undercarriage 2 via a slewing gear for rotation about a vertical axis of rotation 3. The superstructure 4 comprises a telescopic boom 6 mounted for luffing about a horizontal axis, as well as a counterweight arrangement, also referred to as superstructure ballast.

[0046] In this exemplary embodiment, the superstructure ballast comprises a ballast frame 7, which is preferably connected to the steel structure of the superstructure 4 via bolted connections and can be removed from the superstructure 4 for transport. Two hydraulic ballasting cylinders 8 are mounted on the ballast frame 7, the piston rods of which can be extended downwards and each have a coupling piece. A counterweight device 10 can be lifted from a storage area 5 to the superstructure 4 via the ballasting cylinders 8 and connected to it. Conversely, the counterweight device 10 can be deposited back on the storage area 5 by extending the ballasting cylinders 8 and from there loaded onto a transport vehicle, if necessary using an auxiliary crane or the boom 6 of the mobile crane 1.

[0047] In this exemplary embodiment, the storage area 5 is formed by a foldable storage device at the rear of the undercarriage 2, which comprises two pivotable folding parts on which the counterweight device 10 can be mounted. However, the storage area could also be located, for example, on the upper side of the undercarriage 2 or on the ground.

[0048] The counterweight device 10 comprises a counterweight base plate 20, on which one or more plate-shaped counterweight elements 22 are preferably stackable. Furthermore, several suspension weights 50 are provided, which are described further below. This allows the superstructure ballast to be variably configured and adapted to the desired application. In the exemplary embodiment shown here, a single additional counterweight plate 22 is provided (apart from the carrier plate 40 described later). A side view looking towards the rear of the counterweight device 10 is shown in the Fig. 3 shown.

[0049] The coupling of the counterweight device 10 with the ballasting cylinders 8 is effected via coupling elements 30 projecting vertically upwards from the counterweight base plate 20, which have coupling sections 32 at their upper ends for reversible coupling with the coupling pieces of the ballasting cylinders 8 as well as fastening means 36 for fastening the counterweight device 10 to the ballast frame 7. The alignment or positioning of the counterweight device 10 in a mounting position on the ballast frame 7 for establishing the connection via the fastening means 36 is effected via centering means 34 of the coupling elements 30. The centering means 34 and fastening means 36 are shown in a side view in the Fig. 1 (these protrude above the top plate or support plate 40 of the counterweight device 10).

[0050] As in the Fig. As can be seen in Figure 2, which shows the counterweight device 10 during setup from its rear side, the counterweight device 10 comprises a support plate 40, which forms the upper end of the ballast stack comprising the counterweight base plate 20 and the additional counterweight element 22. Additional counterweight elements in the form of suspension weights 50 are attached to the sides of the support plate 40; in the embodiment discussed here, one suspension weight 50 is provided on each side.

[0051] The suspension weights 50 are arranged such that, in the fully assembled (i.e., assembled) state of the counterweight device 10, they extend to the lower counterweight base plate 20. The height of the suspension weights 50 corresponds in particular to the height of the ballast stack of the counterweight device 10.

[0052] According to the invention, the support plate 40 and the suspension weights 50 form a common (first) assembly unit 11, which can be transported and lifted together (in this respect, it can also be referred to as a transport and assembly unit 11). Thus, only a single lift is necessary to raise the support plate 40 and the suspension weights 50 to the storage area 5.

[0053] The counterweight base plate 20 and the further counterweight element 22 placed thereon preferably also form a common (second) mounting unit 12. For this purpose, the coupling elements 30 can have attachment means not shown here (for example in the form of corresponding recesses to which chains or ropes can be attached) in order to be able to lift the lower or second mounting unit 12 via the coupling elements 30.

[0054] A possible embodiment of a storage device 5 of the undercarriage 2 is shown in the Fig. 1. Here, the central ballast, which can be mounted directly on the undercarriage 2 via fastening elements, is extended by a foldable mount for the counterweight device 10. Two pivoting parts are foldably attached to the side walls of the central ballast and have support surfaces on their upper sides on which the counterweight device 10 can be placed.

[0055] To equip the counterweight device 10, the lower assembly unit 12, comprising the counterweight base plate 20 and the counterweight element 22 previously placed on it, is first lifted by a transport vehicle (e.g., a low-loader) and placed on the storage area 5. The lifting is preferably carried out by means of the boom 6 of the mobile crane 1 in self-equipment mode, but could of course also be performed by an auxiliary crane.

[0056] The upper assembly unit 11, comprising the carrier plate 40 and the suspension weights 50, which have also been previously assembled and transported separately, is then placed on the lower assembly unit 12 (preferably by means of the boom 6). The state shortly before placement is shown in the Fig. 2. It can be seen that the space between the suspension weights 50 and below the support plate 40 forms a receiving area 13 for the counterweight base plate 20 and the counterweight element 22, in which the latter components are accommodated in the assembled state (see Fig. 3).

[0057] As in the Fig. As can be seen in Figure 3, the coupling elements 30 connected to the counterweight base plate 20 are of such a length that, when assembled, they protrude beyond the upper side of the support plate 40. For this purpose, both the additional counterweight element 22 and the support plate 40 have correspondingly shaped recesses through which the coupling elements 30 protrude. The coupling elements 30, which could also be referred to as connecting blades, are, in particular, one-piece sheet metal constructions that have a flat basic shape and are connected to the counterweight base plate 20.

[0058] The directions “top” and “bottom” used herein refer to the case where the counterweight base plate 20 (and the mobile crane 1) are on a level surface and the coupling elements 30 are aligned vertically.

[0059] The Fig. 4 shows a plan view of the support plate 40 with the suspension weights 50 attached thereto. The essentially slot-shaped recesses 44 running parallel to one another can be seen, in which the coupling elements 30 are arranged.

[0060] The coupling elements 30 serve both to receive and lift the counterweight device 10 and to center and secure it to the ballasting device (or to the ballast frame 7). For this purpose, the coupling elements 30 have a coupling section 32 at their end opposite the counterweight base plate 20 (see FIG. Fig. 2).

[0061] The coupling section 32 comprises in particular an upwardly open, clamp-shaped recess 33 (cf. Fig. 4), into which a specially shaped (particularly mushroom-shaped) end or coupling piece of the corresponding ballasting cylinder 8 can be retracted laterally. In the final position, in which the counterweight device 10 can be safely lifted, the coupling pieces of the ballasting cylinders 8 are preferably located centrally within the respective recesses 33, which, due to their shape, enable a positive-locking lifting of the counterweight device 10 by retracting the ballasting cylinders 8.

[0062] In the embodiment shown here, the coupling of the ballasting cylinders 8 with the coupling elements 30 is effected by a rotation of the superstructure 4 about its axis of rotation 3. Therefore, the recesses 44 in the central area are to one side (in the Fig. 4 to the left) so that the coupling pieces of the ballasting cylinders 8 can be retracted downwards next to the coupling elements 30 into the widened sections 45 of the recesses 44 until the coupling pieces are at the level of the recesses 33. A coupling can then be established by rotating the superstructure 4. In the exemplary embodiment shown here, the widened sections 45 have a rectangular shape and are arranged slightly offset from one another (ie not at the same height in plan view) in order to take into account the circular path of the ballasting cylinders 8 when the superstructure 4 rotates. Other shapes and arrangements of the recesses 45 are also conceivable.

[0063] After lifting the counterweight device 10 onto the superstructure 4 or ballast frame 7, the coupling elements 30 are bolted to the ballast frame 7. This relieves the load on the ballasting cylinders 8 during crane operation. Therefore, the coupling elements 30 have fastening means 36 in the area of ​​the coupling sections 32 (see Fig. 1 and Fig. 3), which enable a stable connection of the counterweight device 10 to the ballast frame 7. The fastening means 36 are designed in particular as bolt receptacles through which corresponding fastening bolts can be inserted in the assembly position.

[0064] The coupling elements 30 also preferably comprise centering means 34 in the area of ​​the fastening means 36 (see Fig. 1 and Fig. 3), in the embodiment shown here in the form of a projection or mandrel projecting upwards in the longitudinal direction of the coupling element 30 and tapering upwards, via which the counterweight device 10 is brought into the desired mounting position when the ballasting cylinders 8 are retracted. The centering means 34 interact with counter-centering means (not shown) on the ballast frame 7 and ensure automatic alignment of the counterweight device 10 when it is brought closer to the ballast frame 7.

[0065] The suspension weights 50 are detachably attached to the support plate 40 via two connections 100, 200. A first suspension connection 100 is established by means of first connecting elements 41, 51 and enables uncomplicated suspension of the suspension weights 50 on the support plate 40. For this purpose, the suspension weights 50 have connecting plates 54 laterally in the area of ​​the end face facing the support plate 40, which form hook elements 51 in their front sections. The arrangement of the connecting plates 54 is shown in the plan view of the Fig. 4, while the Fig. 5 and Fig. 6 show a top view and a side view of one of these connecting plates 54 in the connected state.

[0066] The hook elements 51 (= first connecting elements of the suspension weights 50) comprise downwardly open recesses 55 in which suspension bolts 41 (= first connecting elements of the support plate 40) are accommodated, which are located in recesses 46 formed at the corners of the support plate 40 (see Fig. 4). The suspension weights 50 are suspended via the hook elements 51 in the suspension bolts 41 of the support plate 40, thereby forming the first suspension connections 100. In principle, it would also be conceivable to provide upwardly open hook elements on the support plate 40 and suspension bolts on the suspension weights 50.

[0067] In addition, the support plate 40 and the suspension weights 50 have second connecting elements 42, 52, 53 for forming a second connection 200, which secures the first suspension connection 100 and prevents accidental detachment of the suspension weights 50. In the exemplary embodiment shown here, the second connecting elements 42, 52, 53 comprise bolt receptacles 42 formed on the support plate 40 in the region of the recesses 46 and bolt receptacles 52 likewise formed on the connecting plates 54, through which corresponding bolts 53 are inserted as soon as the bolt receptacles 42, 52 overlap.

[0068] The recesses 46 are provided on the support plate 40 so that the connecting plates 54 do not protrude laterally beyond the outer contour of the support plate 40, ie the connecting plates 54 are located “inside” the recesses 46 in plan view.

[0069] The second connections 200 or bolt connections not only increase safety when lifting the assembly unit 11 or during crane operation, for example in the event of a sudden load break, but also enable the assembly unit 11 according to the invention to be lifted via the suspension weights 50, as shown in the side view of the Fig. 7. For this purpose, the suspension weights 50 have corresponding attachment means 58 on their sides spaced from the support plate 40, to which a sling rope 60 or a sling chain of a lifting device can be attached.

[0070] Without the second connections 200, the suspension connections 100 would simply detach when lifting the suspension weights 50. The first and second connecting elements 41, 42, 51, 52, 53 are designed to safely absorb and transmit the forces occurring during the lift.

[0071] As in the Fig. 6, the openings 55 of the hook elements 51 have a greater width than the suspension bolts 41 accommodated therein. This defined play allows for easier suspension of the suspension weights 50. A pivoting movement is achieved by a larger bore 52

[0072] This deliberately provided pivoting movement of the suspension weights 50 facilitates the setting down of the upper mounting unit 11 on the lower mounting unit 12 (cf. Fig. 2). During the lifting of the mounting unit 11, the suspension weights 50 are pivoted or spread apart by a defined distance due to the mobility described above. This widens the receiving area 13 between the suspension weights 50, making it easier to insert the lower mounting unit 12 into this receiving area 13.

[0073] Since the support plate 40 can also be used without the suspension weights 50 for certain applications, it also has corresponding lifting devices 48 on its sides. In principle, the assembly unit 11 could also be lifted using these lifting devices 48 of the support plate 40. In this case, however, the above-described advantage of spreading the suspension weights 50 apart would not be achieved.

[0074] The ballast elements 20, 22, 40, 50 can be designed either as a filled box construction or as cast ballast. However, the aforementioned ballast elements 20, 22, 40, 50 are preferably made of a cost-effective and environmentally friendly box construction, into which, for example, metal parts are inserted during production and the spaces between them are filled with a filling compound. However, these have a lower specific gravity, so for many applications, an additional volume of counterweight is necessary to generate the required moment for stability. This additional weight is provided by the suspension weights 50.

[0075] Finally, it should be mentioned that operating personnel may be required to place the counterweight assembly formed by the assembly unit 11 onto the already prepared counterweight assembly of the assembly unit 12 and to establish the connections between them. These activities can be performed from a comfortable and safe position on the undercarriage 2. Entering the exposed counterweight device 10 itself is only necessary to unhook or detach the sling cables 60. However, this generally does not require a great deal of effort. If climbing onto the counterweight device 10 is to be avoided entirely, folding ladders, for example, can be used. List of reference symbols: 1 mobile crane 2 undercarriages 3 axis of rotation 4 superstructures 5 Storage area 6 booms 7 ballast frames 8 ballasting cylinders 10 Counterweight device 11 (Upper) mounting unit 12 Second (lower) assembly unit 13 Recording area 20 Counterweight base plate 22 Counterweight element 30 coupling element 32 Coupling section 33 recording 34 centering devices 36 fasteners 40 carrier plate 41 First connecting element (hanging bolt) 42 Second connecting element (bolt holder) 44 recess 45 Widened section of the recess 46 recess 48 lifting gear 50 hanging weight 51 First connecting element (hook element) 52 Second connecting element (bolt holder) 53 bolts 54 Connecting plate 55 recess 56 lifting gear 58 lifting gear 60 sling rope 100 First connection (hanging connection) 200 Second connection

Claims

[1] Mobile crane (1) comprising a mobile undercarriage (2), a superstructure (4) rotatably mounted on the undercarriage (2) and a counterweight device (10) which can be coupled to the superstructure (4) and has a counterweight base plate (20), a carrier plate (40) and at least two suspension weights (50) which can be detachably connected to the carrier plate (40), wherein the carrier plate (40) can be placed on the counterweight base plate (20) and comprises first connecting elements (41) for establishing a first suspension connection (100) with first connecting elements (51) of the suspension weights (50), characterized byin that the support plate (40) and the suspension weights (50) are designed as a jointly liftable assembly unit (11) and the suspension weights (50) have stop means (58) for lifting the entire assembly unit (11), wherein the support plate (40) comprises second connecting elements (42) for establishing a second connection (200) with second connecting elements (52) of the suspension weights (50), which is designed to block a release of the first suspension connection (100) when the assembly unit (11) is lifted via the suspension weights (50). [2] Mobile crane (1) according to claim 1, wherein the superstructure (4) comprises a ballasting device which is designed to lift the counterweight device (10) from a storage area (5) of the undercarriage (2) and to place it thereon, wherein the ballasting device preferably comprises at least one hydraulic ballasting cylinder (8). [3] Mobile crane (1) according to one of the preceding claims, wherein the counterweight device (10) comprises at least one coupling element (30) extending substantially perpendicular to the counterweight base plate (20) and connected thereto for lifting and coupling the counterweight device (10) to the superstructure (4), wherein the carrier plate (40) preferably has at least one recess (44) through which the at least one coupling element (30) projects in the stored state. [4] Mobile crane (1) according to the two preceding claims, wherein the at least one coupling element (30) has a coupling section (32) at an end opposite the counterweight base plate (20), via which a coupling with the ballasting device, in particular with a ballasting cylinder (8) of the ballasting device, can be established. [5] Mobile crane (1) according to the preceding claim, wherein the coupling section (32) comprises a receptacle (33) into which a coupling piece of a ballasting cylinder (8) can be inserted, in particular by rotating the superstructure (4) about its axis of rotation (3). [6] Mobile crane (1) according to one of claims 3 to 5, further comprising at least one further counterweight element (22) which can be stacked on the counterweight base plate (20) and which has at least one recess through which the at least one coupling element (30) projects in the stored state, wherein the further counterweight element (22) is arranged in the ballasted state between the counterweight base plate (20) and the support plate (40), wherein the counterweight base plate (20) and the at least one further counterweight element (22) preferably also form a jointly liftable second assembly unit (12). [7] Mobile crane (1) according to one of claims 3 to 6, wherein the at least one coupling element (30) comprises a centering means (34), by means of which the counterweight device (10) can be automatically positioned in an assembly position when it is lifted on the superstructure (4), and / or a fastening means (36), via which the counterweight device (10) can be detachably connected to the superstructure (4) in an assembly position and which preferably has a bolt receptacle for establishing a bolt connection with the superstructure (4). [8] Mobile crane (1) according to one of the preceding claims, wherein the second connections (200) form axes of rotation for the suspension weights (50) and are designed such that the suspension weights (50) pivot about the axes of rotation when the assembly unit (11) is lifted relative to the support plate (40) and thus spread apart laterally by a defined distance, wherein the rotational movements are preferably limited by a stop of the first connecting elements (41, 51). [9] Mobile crane (1) according to one of the preceding claims, wherein the first connecting elements (41, 51) comprise suspension bolts (41) arranged on the support plate (40) and hook elements (51) arranged on the suspension weights (50), wherein the hook elements (51) comprise a recess (55) open to one side. [10] Mobile crane (1) according to one of the preceding claims, wherein the support plate (40) has recesses (46) within which the first and second connecting elements (41, 42) are arranged such that they do not protrude beyond the outer contour of the support plate (40) in plan view. [11] Mobile crane (1) according to one of the preceding claims, wherein the counterweight device (10) is designed such that, in the lowered state of the carrier plate (40), the suspension weights (50) connected thereto are arranged laterally next to the counterweight base plate (20). [12] Mobile crane (1) according to one of the preceding claims, wherein two coupling elements (30) spaced apart from one another are connected to the counterweight base plate (20) and preferably have a flat shape. [13] Counterweight device (10) for a mobile crane (1) according to one of the preceding claims, preferably further comprising a counterweight element (22) that can be stacked at least on the counterweight base plate (20). [14] Method for mounting the counterweight device (10) on the superstructure (4) of a mobile crane (1) according to one of claims 1 to 12, comprising the following steps: - placing the counterweight base plate (20) on a storage area (5) of the undercarriage (2), in particular by means of a boom (6) of the mobile crane (1), - Lifting the assembly unit (11) from the support plate (40) and the suspension weights (50) connected thereto via the lifting means (58) of the suspension weights (50), - placing the assembly unit (11) on the counterweight base plate (20), - Lifting the entire counterweight device (10) via a ballasting device of the mobile crane (1) to the superstructure (4), in particular by coupling at least one ballasting cylinder (8) to at least one coupling element (30) connected to the counterweight base plate (20) and projecting through the carrier plate (40). [15] Method according to the preceding claim, wherein the mobile crane (1) is designed at least according to claim 8 and the suspension weights (50) spread apart laterally when the assembly unit (11) is lifted, so that the assembly unit (11) in the spread-out state forms a widened receiving area (13) for the counterweight base plate (20) and can be set down thereon, wherein the suspension weights (50) are preferably arranged next to the counterweight base plate (20) when set down and pivot towards it.

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