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

Abstract

Mobile crane (10) comprising a mobile undercarriage (12), an uppercarriage (14) rotatably mounted on the undercarriage (12), and a counterweight device (20) which can be coupled to the uppercarriage (14), said counterweight device comprising a counterweight base plate (22) and at least one connecting element (30) extending substantially perpendicularly to the counterweight base plate (22) and connected thereto for lifting the counterweight device (20) and coupling the counterweight device (20) to the uppercarriage (14), characterized in that the counterweight device (20) comprises a carrier plate (40) which can be connected to the at least one connecting element (30) above the counterweight base plate (22), wherein at least one pivoting carrier (42) is pivotably mounted on the carrier plate (40) about a vertical axis (43), on which pivoting carrier at least one first counterweight element (50) can be stacked.

Description

The present invention relates to a mobile crane according to the preamble of claim 1, to a counterweight device for such a mobile crane and to a method for mounting a counterweight device on such a mobile crane.Mobile cranes typically have a undercarriage with a wheel or track undercarriage, an undercarriage mounted on the undercarriage such that it can rotate about a vertical axis, a boom attached pivotably to the undercarriage, and a counterweight device also referred to as an undercarriage ballast. In any position of the superstructure, the counterweight applies a counter-moment to the load moment via a lever arm and therefore rotates with the superstructure.Whereas smaller mobile cranes often carry all pieces of equipment for use on the construction site, also in public road traffic, as so-called taxi cranes, larger mobile cranes are not capable of this, however, so that it is necessary to remove crane components and in particular the counterweight device completely or partially for transport in public road traffic and to mount them on site. In the case of caterpillar cranes as well, the counterweight device is typically to be disassembled for transport and mounted on the superstructure at the place of use.It is therefore known from the prior art to provide a carrier plate or a counterweight base plate with connecting elements for releasable connection to the superstructure, on which several counterweight elements can be stacked. The superstructure is provided with a ballast device which is capable of receiving the counterweight device comprising the counterweight base plate and the counterweight elements stacked thereon at the connecting elements from the floor or from a storage region on the undercarriage for mounting and lifting it to the superstructure. For disassembly, the counterweight base plate with the counterweight elements can be placed back on the floor or the undercarriage.For this purpose, the ballasting device usually comprises one or more hydraulic ballasting cylinders which extend downward, are brought into engagement with the connecting elements of the counterweight device and, by retraction, lift the counterweight device to the superstructure.In the prior art, the connecting element used is, inter alia, cylindrical receiving tubes which are welded to the counterweight base plate and project vertically upward therefrom. The counterweight elements have corresponding recesses through which the receiving tubes project, so that in the stacked state the ballasting cylinders can be brought into engagement with the receiving tubes from above, for example in combination with a rotational movement of the superstructure. Such receiving tubes are exposed to high loads and sometimes considerable transverse forces during crane operation and therefore usually have stiffening elements in the form of stiffening plates which are welded to the counterweight base plate and the receiving tube. Instead of cylindrical receiving tubes, flat connecting elements can also be used, which likewise frequently have corresponding reinforcements in order to be able to reliably withstand the transverse forces occurring during oblique positioning or when cornering.The connection of the counterweight device to the superstructure generally presents a challenge-not least because of the considerable weight of the counterweight device and the dynamic forces which sometimes occur during crane operation. Thus, on the one hand, the counterweight device must be held securely and stably on the superstructure. For this purpose, it is known, for example, that the ballasting cylinders hold the counterweight device on the superstructure during the crane operation. On the other hand, the connection of the counterweight device to the superstructure should be able to be carried out in an uncomplicated and quick manner.For mounting the counterweight device, it is usually deposited on a storage area on the undercarriage and the counterweight elements are stacked on the counterweight base plate. The superstructure rotates with its ballasting device over the stacked counterweight device and the ballasting cylinders pull the latter to the superstructure at the connecting elements.This known mounting system limits the size of the mountable volume of the counterbalance device. The upper shelf surface on the undercarriage that receives the counterweight device for mounting defines the lower limit of the mountable volume of the counterweight device. The plane through the lowest point on the ballasting device determines the upper limit of the mountable volume of the counterweight device. If the counterweight device has a height that exceeds this distance, the superstructure collides with the counterweight device that has been stacked up.Furthermore, the counterweight device cannot extend anywhere from the vertical axis of rotation of the superstructure. Here, the undercarriage typically has other components such as a driver's cab, an engine housing, components of the exhaust gas aftertreatment system or the like, so that the counterweight device cannot extend in this region. The counterweight device cannot likewise extend closer to the vertical axis of rotation of the superstructure, since the steel structure of the superstructure is located there.If the mass of the counterweight is now to be increased further, this could only be achieved by increasing the specific weight of the counterweight elements with the volume remaining the same. However, this makes the production and obtaining of the counterweight elements complicated and expensive.It is known from DE 20 2014 008 661 U1 to change the distance of the ballasting cylinders and thus of the center of gravity of the accommodated counterweight from the upper carriage axis of rotation in order to increase the counterweight moment. This distance can be set permanently before the counterweight is set up. However, a disadvantage of this solution is that the counterweight radius can no longer be changed during the crane work. As a result, the counterweight radius cannot be adapted to the prevailing space conditions of the construction site, for example in the case of a specific rotational movement. In addition, an additional tilting criterion results, particularly in mobile cranes with a variable supporting base. If there is little space on the construction site, mobile cranes with such a variable support base are frequently set up with a support pushed far out in the direction of the lifting work. As a result, a large support base is present in this direction, but the support in the opposite direction (toward the rear) is usually extended slightly, so that after the load has been placed down there is the risk of a "rearward tilting".Other solutions such as those of DE 10 2016 009 013 A1 use pivotable counterweight base plates. The mounting of such counterweight devices is, however, complicated, since the counterweight devices carry their own ballasting cylinders in order to press themselves against the superstructure from below. Thus, before the counter weight is set up, a hydraulic connection to the ballasting cylinders of the counter weight device is to be established. Furthermore, a secure, stable mounting of the counterweight device on the ballasting cylinders must be ensured so that the latter does not tilt when it is pressed up.Finally, nowadays, the CO 2- balance is also a relevant factor. In this case, the transport of heavy counterweight elements is a disadvantageous module.Heavy counterweight elements quickly load transport vehicles, as a result of which additional transport vehicles have to be used and the CO 2- balance is impaired as a result.A mobile crane of the generic type is known from DE 20 2021 106 818 U1.Against this background, the object of the present invention is to specify a counterweight device for generic mobile cranes which can be fastened to the superstructure in a simple and reliable manner and with which a high counterweight moment can be generated during operation.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 14 and a method having the features of claim 15. Advantageous embodiments of the invention are evident from the dependent claims and the following description.Accordingly, on the one hand a mobile crane is proposed which comprises a mobile undercarriage, an undercarriage mounted rotatably on the undercarriage and a counterweight device which can be coupled to the undercarriage. In particular, a boom, for example a telescopic boom, is articulated to the superstructure in a luffing manner. The counterweight device comprises a counterweight base plate and at least one connecting element for raising the counterweight device and for coupling the counterweight device to the superstructure. The at least one connecting element is connected to the counterweight base plate and extends substantially perpendicularly to the counterweight base plate. If, for the sake of simplicity, only "the connecting element" is mentioned below, this is to be understood as the at least one connecting element, i.e. if appropriate also comprises further connecting elements present.According to the invention, the counterweight device comprises a carrier plate which can be connected to the at least one connecting element above the counterweight base plate. "Above" relates here to a situation in which the counterweight base plate (or the mobile crane) is placed on a horizontal underlying surface and the connecting element extends vertically upwards. When the counterweight device is mounted, the carrier plate is consequently located between the counterweight base plate and the connection point of the connecting element to the superstructure.According to the invention, at least one pivot carrier is mounted on the carrier plate so as to be pivotable about a vertical axis, wherein at least one first counterweight element can be stacked on the pivot carrier. In the present case, counterweight elements which are deposited or stacked on pivot carriers are referred to as "first counterweight elements". The pivot carrier thus serves as an additional base plate, which is pivotable relative to the support plate and on which further (first) counterweight elements or a counterweight stack can be arranged. By means of the pivotability about the vertical axis (this in turn relates to a situation with a planar, horizontal underlying surface), the distance of the first counterweight element mounted on the pivot carrier from the axis of rotation of the superstructure can be varied. As a result, for example, the total counterweight moment generated by the counterweight device can be increased or decreased or the space occupied by the counterweight device can be reduced in order to be able to rotate the superstructure in confined space conditions.The counterweight stack which can be mounted on the pivot carrier (this can also comprise only a single first counterweight element, but preferably a plurality of first counterweight elements) is not restricted at the top, such that the total weight or the volume of the counterweight can be increased without problems occurring during the assembly or disassembly of the counterweight device.At the same time, the counterweight device is securely and stably mounted via the at least one connecting element, via which the counterweight base plate, any additional counterweight elements deposited thereon, and the carrier plate with the pivot carrier and the counterweight supported thereon can be lifted together on the superstructure and mounted thereon. This can preferably be effected via ballasting cylinders which are fastened to the superstructure and pull the counterweight device upwards on the at least one connecting element. This simplifies the assembly and disassembly process in comparison with solutions in which the ballasting cylinders are part of the counterweight device.Thus, the at least one connecting means constitutes the traction element and the fastening element for the entire counterweight device in one, which reduces the number of components, facilitates the operation or assembly and ensures a stable connection of the various components.The at least one connecting element can be formed in one piece. This eliminates the need for welded connections to other components which are expensive to produce, which facilitates the production process.The at least one connecting element is preferably designed as a one-piece sheet metal construction having an in particular substantially flat shape. Such a sheet metal construction is easier to produce than, for example, a cylindrical receiving tube and can be produced with a suitable thickness in order to withstand the various loads acting along and transversely to its longitudinal axis. The at least one connecting element can optionally be produced as a burning part from a thick sheet which is easy to obtain, inexpensive and subject to large tolerances. The contour may be fired and machined in some locations.In one possible embodiment, it is provided that the at least one connecting element is firmly connected, in particular welded, to the counterweight base plate. The connecting element can be welded to an upper side of the counterweight base plate or be immovably accommodated in a recess of the counterweight base plate and firmly connected to the counterweight base plate. The connection between the connecting element and the counterweight base plate, in particular the weld seam, is designed in such a way that it can be sufficiently loaded, in particular with regard to transverse forces which can occur, for example, when the mobile crane is inclined or is travelling in a curve.Alternatively, the at least one connecting element can be accommodated in a recess of the counterweight base plate, wherein preferably no completely fixed connection is present, but a movement of the connecting element along its longitudinal axis relative to the counterweight base plate is possible within a certain frame. In particular, the connecting element can have a base section, a central section and a coupling section, wherein the base section is accommodated in the recess of the counterweight base plate and the central section protrudes through an opening of the recess. The end of the connecting element opposite the counterweight base plate can have a coupling section which serves for coupling to the superstructure. The counterweight base plate can rest on a placement surface of the base section on the connecting element, wherein the recess preferably allows a movement of the base section within the recess in the longitudinal direction of the connecting element. The recess can be open toward an underside of the counterweight base plate and optionally covered by a cover plate.Due to this degree of freedom of movement, which results from the certain displaceability of the base section within the recess, in the raised state the counterweight base plate (and all counterweight elements possibly stacked thereon) lies completely on the at least one connecting element and the connecting element does not touch the cover. The cover is therefore not loaded in this state. Only in a state deposited on the floor or a storage area the weight of the connecting element loads the cover. Due to the mobility of the connecting element within the recess and the preferably non-existing connection to the cover, the latter is not loaded laterally in the event of an oblique position of the counterweight device or in the event of the occurrence of transverse forces, but at most a slight frictional connection or frictional load is possibly applied.In a further possible embodiment, a ballasting device is provided on the superstructure, which is configured to lift the counterweight device from a storage region of the undercarriage and to store it thereon. The counterweight device can be detachably connected in particular to the ballasting device, i.e. the ballasting device preferably performs a dual function: the raising and lowering of the counterweight device and the fastening thereof to the superstructure.Preferably, the at least one connecting element has a coupling section at an end opposite the counterweight base plate (i.e. pointing towards the superstructure or the ballasting device), via which coupling section a mechanical coupling with the ballasting device can be produced. The coupling section can comprise a receptacle into which a lifting device of the ballasting device, in particular a ballasting cylinder, can be retracted in order to produce a connection for lifting the counterweight device.In a further possible embodiment, it is provided that the ballasting device comprises at least one hydraulic ballasting cylinder which can be releasably brought into engagement with the coupling section or the receptacle thereof of the at least one connecting element. The ballasting cylinder has in particular a piston rod which can be extended downward by the ballasting device and can be coupled to the coupling section of the connecting means. Preferably, two or more ballasting cylinders and a corresponding number of connecting elements are provided.Preferably, the ballasting device comprises a ballast frame which preferably carries the ballasting cylinder or cylinders.Preferably, the coupling section of the connecting means comprises a receptacle in the form of an upwardly open recess into which a coupling piece of the ballasting cylinder can be moved, in particular by rotating the superstructure about its vertical axis of rotation. The coupling piece can be part of the piston rod of the ballasting cylinder or a component connected to the latter. The coupling piece can be lockable in the recess, for example by means of a specifically provided locking device. Alternatively or additionally, the locking can simply result from a mechanical stop which blocks a further movement of the coupling piece relative to the coupling section.The receiving means of the coupling section can be configured in a manner known per se such that it allows lateral (e.g. following a circular movement) insertion of the ballasting cylinder and, in the connected state (i.e. in the assembly position in which the counterweight device can be lifted by insertion of the ballasting cylinder or cylinders), blocks a movement of the ballasting cylinder out of the recess in a vertical direction in a positive-locking manner. In the raised state, the counterweight device can rest on the coupling piece of the at least one ballasting cylinder or hang on the latter via the recess of the at least one connecting element.In a further possible embodiment, at least one second counterweight element is provided, which can be deposited or stacked on the counterweight base plate and has at least one recess through which the at least one connecting element projects in the deposited state. Herein, counterweight members that are directly stacked on the counterweight base plate are referred to as "second counterweight members". The second counterweight element is in particular plate-shaped. A plurality of second counter weight members or plates may be provided, which may be stacked on the counter weight base plate.The counterweight base plate represents in particular the lowermost counterweight element of the counterweight device, on which all second counterweight elements which may additionally be provided can be stacked. The recesses of all second counterweight elements overlap at least partially in this case, so that the at least one connecting element can project through the stack and is accessible from above.Above this stack of counterweight base plate and optionally the one or more second counterweight elements, the carrier plate is connected to the connecting element. In other words, the second counterweight element (or the stack of a plurality of second counterweight elements) is arranged between the counterweight base plate and the carrier plate in the ballasted state. The two counterweight element is in particular not braced during ballasting.For a stable mounting of the counterweight elements and connection of the counterweight device on the superstructure, preferably more than one connecting element is provided. In a further possible embodiment, the counterweight device therefore comprises at least two connecting elements spaced apart from one another and connected to the counterweight base plate. Preferably, exactly two connecting elements are provided, wherein more than two connecting elements can also be provided. The connecting elements are in particular 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 connecting elements.The connecting elements can be arranged rotated relative to one another (in each case about a vertical axis). This may be due to the fact that the ballasting cylinders are moved on a circular path by rotating the superstructure in order to establish the coupling with the connecting elements. In this case, the connecting elements can be designed as flat sheet metal constructions which are not oriented parallel to one another but are oriented inclined at a specific angle to one another. Preferably, however, the connecting elements are not rotated relative to each other, but are arranged parallel to each other. This simplifies the production of the counterweight base plate and of the carrier plate and of the second counterweight element.The counterweight base plate and / or the carrier plate and / or the at least one pivot carrier and / or the at least one first counterweight element and / or the at least one second counterweight element are in particular each formed by a box, in particular a steel box, into which weights, in particular solid metal blocks, are inserted during production. The box is then filled with a binder and brought to the desired weight. The balances thus produced should be inexpensive, robust and heavy. The binder may have a lower specific density than the inserted metal. Large and massive metal components are thus advantageous. The more complicated the shape of the counterweight base plate or counterweight elements and the more bulges and interruptions, the more difficult the manufacture or the design of the steel box with massive weights or blocks becomes. Because the connecting elements are preferably arranged parallel to one another, geometrically ideal regions are obtained for filling the respective steel boxes with massive weights during production.Alternatively, one or more of the gray cast-metal type panels mentioned in the preceding paragraph may be provided. Overall, the space available in the region of these plates or elements is small, so that the greatest possible specific weight should be used. The connecting element and optionally the counterweight base plate must also introduce a large force (weight force of the carrier plate, of the at least one pivot carrier and of the at least one first counterweight element accommodated thereon) into the undercarriage without suffering damage itself.In the case of the parallel arrangement of the connecting elements, it should be noted that the ballasting cylinders move in particular on a circular path during the mounting of the counterweight device. This circumstance must be taken into account accordingly in the design of the connecting means or of the coupling sections of the connecting means. This can be effected, for example, via sufficiently large receptacles of the coupling sections. Alternatively or additionally, arcuate receptacles or other solutions would also be conceivable.Preferably, at least two pivot carriers are mounted on the carrier plate such that they can be pivoted about a vertical axis, wherein at least one first counterweight element, preferably a counterweight stack in each case, can be mounted on each of the pivot carriers. The pivot carriers can be pivotable independently of one another. As a result, the space occupied by the counterweight device can be flexibly adapted to the respective situation of use, for example with regard to restricted space conditions or obstacles or with regard to the counterweight moment generated. A mechanical coupling of a plurality of pivot carriers to one another can also be envisaged in order to enable a synchronous pivoting movement of all pivot carriers. As a result, the total center of gravity always moves along a defined line, in particular.Preferably, the pivot carriers in the erected state are arranged symmetrically to a central plane of the superstructure running through the vertical axis of rotation of the superstructure. Exactly two pivot carriers can be provided, wherein an embodiment with more than two pivot carriers is also conceivable, which can be mechanically coupled to one another, for example, on each side of the mentioned central plane.In a further possible embodiment, it is provided that the at least one connecting element has a support surface via which the counterweight base plate rests on the connecting element at least in the absence of an oblique position of the mobile crane and introduces its weight force into the latter. The deposition surface can be a continuous surface or a plurality of subareas. The placement surface or the optionally multiple sub-surfaces can / can comprise flat and / or beveled and / or curved regions. Preferably, at least two deposition surfaces are provided on opposite sides of the connecting element. As a result, the counterweight base plate can be supported stably on the connecting element.Alternatively or additionally, the at least one connecting element can comprise a centering means, by means of which the counterweight device can be positioned on the superstructure in an assembly position. The centering means interacts in particular with a counter-centering means on the superstructure and ensures automatic positioning of the counterweight device during the lifting to the superstructure. Centering the counterweight device in an intended mounting position on the superstructure facilitates its mounting.In this case, the superstructure preferably comprises a corresponding counter-centering means which is designed, when the counterweight device is raised by interaction with the centering means of the connecting element, to automatically position the counterweight device in an installation position in which it can be connected to the superstructure, in particular to the ballasting device mentioned. Preferably, the centering means is formed as an element extending substantially in the longitudinal direction of the connecting element, e.g. as a projection. The counter-centering means accordingly forms a recess into which the centering means enters when the counterweight device is lifted. However, the reverse case (centering means as a recess and counter-centering means as a projection or the like projecting downward from the superstructure) is likewise conceivable. The centering means preferably comprises at least one beveled surface or chamfer, i.e. it can have one or more beveled surfaces, for example in one or two directions, in order to facilitate the insertion of the centering means and the counter-centering means into one another. A conical shape with a circumferential chamfer of centering means or counter-centering means is likewise possible.Alternatively or additionally, the at least one connecting element can comprise a fastening means, by means of which the counterweight device can be detachably connected to the superstructure in an assembly position (in particular the assembly position achieved by the aforementioned precentration). The counterweight device is therefore in particular not held on the superstructure during crane operation, for example, by one or more ballasting cylinders, but rather a separate connection is provided which is produced on the superstructure via the fastening means of the at least one connecting element and in particular via corresponding connecting means. As a result, the counterweight device including the carrier plate connected to the connecting element can be fastened securely and stably to the superstructure, so that ballasting cylinders which are optionally provided are relieved after the lifting and fastening.The at least one connecting element preferably has both a centering means and a fastening means. The at least one connecting element thus performs a multiple function: it serves, on the one hand, for raising and lowering the entire counterweight device and, on the other hand, ensures a correct positioning of the counterweight device on the superstructure for the purpose of producing a detachable connection. The latter function, namely the fastening of the counterweight device to the superstructure, is also taken over by the at least one connecting element via its fastening means. Thus, the at least one connecting element constitutes the tension element, centering element and fastening element in one, which reduces the number of components and facilitates operation. Preferably, all these functions are combined in a single unit, in particular without assemblies welded on in a complicated manner.The connecting element may comprise a stop element for fastening a stop means (e.g. a chain or a cable) of a hoist for lifting the counterweight base plate. As a result, the counterweight base plate together with the connecting element(s) can be lifted by an auxiliary crane or the mobile crane itself to be set up and positioned for example on a storage region of the undercarriage. Preferably, the stop element is formed by a recess of the connecting element. Hook elements, projections or the like are also conceivable in order to be able to fasten the stop means.Preferably, the counterweight base plate comprises at least one storage centering means on its underside for positioning the counterweight device on the storage region of the undercarriage. Preferably, the storage area comprises at least one corresponding counter storage centering means, which can be brought into engagement with the storage centering means for the correct positioning of the counterweight device on the undercarriage. This allows the counterbalance device to be oriented in a correct position required for smooth engagement with the ballasting means, particularly smooth engagement of the ballasting cylinders. The tray centering means can be a recess and the counter-tray centering means can be a projection, bolt or another protruding element that can be introduced into the recess (or vice versa).In a further possible embodiment, it is provided that the at least one pivot carrier is continuously pivotable relative to the carrier plate via a pivot drive. Such a pivot drive is necessary in particular since the bearing forces in the vertical pivot bearing are very large. The pivot drive can preferably be a hydraulic cylinder, but also any other actuator, such as an electric drive. The pivot drive is preferably connected in an articulated manner both to the carrier plate and to the pivot carrier. However, the pivot drive does not necessarily have to connect the carrier plate and the pivot carrier directly to one another. A lever system would also be possible in order to make optimum use of the geometry.The pivot angle of the pivot carrier is preferably detected via at least one sensor and made available to a crane controller for evaluation, for example. Thus, the control is able to take into account intermediate positions in the crane monitoring system.In a further possible embodiment, it is provided that the at least one connecting element has a support surface on which the carrier plate can be placed, in particular in such a way that the weight force of the placed carrier plate is introduced only into the at least one connecting element and not into the counterweight base plate or into a second counterweight element placed thereon. The bearing surface can be a continuous surface or a plurality of partial surfaces. The bearing surface or the optionally multiple sub-surfaces can / can comprise flat and / or beveled and / or curved regions. Preferably, at least two support surfaces are provided on opposite sides of the connecting element, particularly preferably four support surfaces, which are distributed in particular around the connecting element. As a result, the carrier plate can be supported stably on the connecting element. The carrier plate can have a corresponding counter-bearing surface which rests on the bearing surface of the connecting element.In a further possible embodiment, it is provided that the carrier plate comprises at least one recess through which the at least one connecting element protrudes in the connected state. The carrier plate is thus pushed or "threaded" onto the at least one connecting element from above and in particular is lowered until it rests on the bearing surface of the connecting element.The end of the connecting element projecting through the carrier plate or at the top out of the carrier plate preferably comprises a fastening means, by means of which the counterweight device can be detachably connected to the superstructure. As a result, the entire counterweight device can be connected, in particular bolted, to corresponding connecting means of the superstructure after being raised to the superstructure.The connecting means has in particular the coupling section described above for coupling to a corresponding coupling piece of a ballasting cylinder. Preferably, the coupling section or its receptacle is arranged such that in the connected state it lies within the recess of the carrier plate. Preferably, the recess of at least the carrier plate is configured such that the coupling piece of the ballasting cylinder can be positioned within the recess next to the coupling section of the connecting element and can be moved into the coupling section or its receptacle by rotating the superstructure about its vertical axis of rotation. The ballasting cylinder describes a circular path and enters the coupling section laterally. The recess of the carrier plate must therefore be correspondingly wider in order to allow such a circular movement when coupling the ballasting cylinder to the connecting element. The second counterweight element or elements which may be situated below it can, on the other hand, be configured differently, with the result that substantially only the connecting element fits through.The recess of the carrier plate can have a mechanical stop against which the coupling piece of the ballasting cylinder abuts in a locking position in which the ballasting cylinder and the connecting element are correctly coupled to one another, in which the counterweight device can thus be lifted by the at least one ballasting cylinder. The stop can be formed by a wall of the recess itself, whereby a particularly simple embodiment results. Alternatively, the stop can also be realized by a separate component arranged in the recess.In a further possible embodiment, it is provided that the carrier plate and the at least one connecting element each have connecting means for producing a releasable connection, in particular a bolt connection, with one another. These connecting means, which serve to produce a fixed connection, i.e. a connection that does not permit a relative movement (but nevertheless can be released), between connecting element and carrier plate, are provided in particular in addition to the bearing and counter bearing surfaces of connecting element and carrier plate described above. By means of these bearing and counter bearing surfaces, the carrier plate is merely placed on the connecting element. The connection between the connecting element and the carrier plate, which is actually provided for the operation and the movement-free transmission of the forces and torques occurring, is however produced by the connecting means. The connecting element can have as connecting means one or more bolt receptacles which are brought into overlap with corresponding bolt receptacles in the carrier plate before corresponding bolts are placed.Optionally, it can be provided that the at least one pivot carrier is removable from the carrier plate for transport. For storing the at least one pivot carrier during transport, the mobile crane can have at least one receptacle on the undercarriage and / or on the superstructure.In a further possible embodiment, it is preferably provided that the at least one first counterweight element has a substantially triangular basic shape or cross-sectional area (in plan view). This allows the center of gravity of the movable part of the counterweight device (i.e. pivot beam together with the first counterweight element or elements stacked thereon) to move further away from the axis of rotation of the superstructure about the undercarriage than the extreme point of the counterweight device in comparison. Thus, the extreme point of the counterweight device forming the pivot radius or ballast radius of the superstructure, which determines the space required on the construction site, is enlarged less greatly than the center of gravity of the movable part of the counterweight device, which center of gravity is displaced outwards in order to generate the higher counterweight moment.For handling the first counterweight elements and optionally the pivot carrier, an assembly device as is known from DE 20 2004 009 497 U1 can optionally be used. For this purpose, the first counterweight elements can be designed correspondingly and in particular each have a corresponding central recess into which the mandrel-shaped mounting device can be introduced.The pivot carrier together with the counterweight element(s) can be moved by lateral pivoting from a first position resting against the carrier plate into a second position, wherein the center of gravity of the arrangement of pivot carrier and counterweight element(s) is at a greater distance from the axis of rotation of the superstructure in the second position than in the first position. The first position can be characterized by complete retraction of a corresponding pivot drive.In the second position and with the connection between the superstructure and the counterweight device released, the superstructure is freely rotatable relative to the counterweight device without colliding with it. This is relevant in particular for a self-assembly of the counterweight mounted on the pivot carrier. In order for the mobile crane to be able to place one or more first counterweight elements on the pivot carrier with its own boom, the superstructure must be freely rotatable without colliding with the counterweight device placed on the undercarriage. For this purpose, it may be necessary to establish a temporary electrical and / or hydraulic connection to the counterweight device in order to operate the pivot drive and to be able to move the pivot carrier into the second position. Then, the superstructure can be freely rotated for receiving a first counterweight member and being seated on the pivot beam without colliding with the counterweight deviceThe pivot carrier can be movable by further pivoting into a third position, in which the center of gravity of the arrangement of pivot carrier and counterweight element(s) is at an even greater distance from the axis of rotation of the superstructure than in the second position. The third position can be characterized by complete extension of the pivot drive. In particular, any intermediate position between the first and the third position can be considered as the second position, in which no collision with the at least one first counterweight mounted on the pivot carrier takes place during a rotation of the superstructure relative to the counterweight device.The counterweight base plate together with the connecting element(s) can have a construction that is axially symmetrical with respect to a central axis running through the center of the counterweight device.The counterweight base plate and / or the at least one second counterweight element which can be deposited thereon can have a curved shape, i.e. a shape deviating from a rectangle, in plan view.Preferably, the carrier plate and the at least one connecting element are dimensioned, in particular with respect to their height, such that the counterweight device in the connected state to the superstructure does not collide with a disturbing region, in particular an engine housing and / or a driver's cab and / or a device for exhaust gas aftertreatment, of the undercarriage during a rotation of the superstructure. In particular, a lowermost edge of the pivot carrier in the connected state lies above an uppermost edge of the interference region. The ballast plate and optionally second counterweight elements supported thereon, on the other hand, can be situated partially below the uppermost edge of the interference region, since their outer edges are in particular at a smaller distance from the axis of rotation of the superstructure than the radially outer edges of the pivot carrier, at least in a fully extended (third) position.The invention further relates to a counterweight device for a mobile crane according to the invention. The same advantages and properties are obviously obtained here as for the mobile crane according to the invention, for which reason a repeated description is omitted. Preferably, the counterweight device further comprises at least one first counterweight element which can be deposited or stacked on the pivot carrier. Alternatively or additionally, the counterweight device can furthermore comprise at least one second counterweight element which can be deposited or stacked on the counterweight base plate.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 fastened to the superstructure of the mobile crane,connecting the carrier plate to the at least one connecting element,raising the counterweight device via the at least one connecting element, in particular by coupling at least one ballasting cylinder of the superstructure to the at least one connecting element and subsequently retracting the ballasting cylinder,establishing a connection, in particular a bolt connection, between the at least one connecting element and the superstructure. Preferably, a connection is made between a fastening means of the connecting element projecting through the carrier plate and a ballasting device of the superstructure.The same advantages and properties as for the mobile crane according to the invention are obviously obtained here, for which reason a repeated description is omitted. In particular, reference is made to the possible embodiments and optional features discussed within the scope of the mobile crane according to the invention, which apply analogously to the method according to the invention.In one possible embodiment of the method, it is provided that the step of connecting the carrier plate to the at least one connecting element comprises the following steps:guiding the carrier plate to the at least one connecting element, in particular by means of the boom of the mobile crane,inserting the at least one connecting element into the corresponding recess of the carrier plate,placing the carrier plate on the above-described bearing surface of the at least one connecting element, so that the carrier plate only rests on the connecting element or the bearing surface,connecting the carrier plate to the at least one connecting element via the connecting means, in particular by producing a bolt connection.If the pivot carrier has been removed from the carrier plate for transport, the method may further comprise the step of connecting the pivot carrier to the carrier plate.Optionally, the method may comprise depositing or stacking at least one first counterweight element on the pivot carrier before the counterweight device is raised above the at least one connecting element. This can be done via an external hoist (e.g. an auxiliary crane). In this case, the pivot carrier does not necessarily have to be pivoted out. Preferably, however, the stacking takes place in self-assembly by the mobile crane itself. As a result, it must be able to rotate relative to the carrier plate or the swivel carrier. In this case, the method can also comprise the step of establishing a hydraulic and / or electrical connection of the mobile crane to a pivot drive of the carrier plate. The pivot drive is then actuated in order to pivot the pivot carrier into a position in which the superstructure does not collide with the latter during rotation. The counterweight device rests on the undercarriage and the pivot carriers are pivoted out to such an extent (second position) that the superstructure can freely rotate. Subsequently, the at least one first counterweight element can be placed on the pivot carrier, i.e. the crane can now automatically stack the at least one counterweight element or a tower of counterweight elements on the pivot carrier. In this case, the entire counterweight device remains only lying on the undercarriage and does not tilt. Thereafter, the electrical and / or hydraulic connection can be disconnected again, wherein the pivot carrier is preferably pivoted in again beforehand. The disconnection can take place before or after the lifting and mounting of the counterweight device on the superstructure.For dismantling the counterweight device, the steps mentioned can be carried out in the reverse sequence (method for dismantling the counterweight device according to the invention from the superstructure of a mobile crane according to the invention).Further features, details and advantages of the invention are evident from the exemplary embodiments explained below with reference to the figures. The following are shown: FIG. 1 : a lateral partial view of a mobile crane known from the prior art; FIG. 2 : shows the counterweight device according to the invention according to a preferred exemplary embodiment in a perspective view; FIG. 3 : a partial view of the mobile crane according to the invention according to a preferred embodiment with mounted counterweight device in a perspective view; FIG. 4 : a top view of the mobile crane with the counterweight device placed on the undercarriage in a first position; FIG. 5 : shows the mobile crane according to FIG. 4 in a side view; FIG. 6 : a top view of the mobile crane with the counterweight device placed on the undercarriage in a second position; FIG. 7 : shows the mobile crane according to FIG. 6 in a side view; FIG. 8 : a plan view of the mobile crane with the counterweight device mounted on the superstructure in a third position; FIG. 9 : shows the mobile crane according to FIG. 8 in a side view; and FIG. 10 : shows the mobile crane in a lateral view with the counterweight device uncoupled from the superstructure.FIG. 1 shows an example of a mobile crane 1 known from the prior art in a side view. The mobile crane 1 has a undercarriage 12 with a wheel chassis and an undercarriage 14 mounted on the undercarriage 12 such that it can rotate about a vertical axis of rotation 13 via a slewing gear. In FIG. 1, only the steel construction of the lower and upper carriages 12, 14 is shown. A boom is articulated to the superstructure 14 in a luffing manner about a horizontal axis (not shown), for example a telescopic boom. On the steel construction of the superstructure 14, a ballast frame 16 of a ballasting device is bolted. The ballasting device comprises two hydraulic ballasting cylinders 18 in order to receive from a storage region of the undercarriage 12 or to place it thereon a counterweight device 5, also referred to as superstructure ballast, having a counterweight base plate 2 and a plurality of counterweight plates 3 stacked thereon. The counterweight device 5 is bolted to the ballast frame 16 after lifting via connecting means 4.For mounting the counterweight device 5, it is stacked on the undercarriage 12. The superstructure 14 rotates with its ballasting device via the counterweight device 5 and the ballasting cylinders 18 pull them onto the superstructure 14.In FIG. 2, the counterweight device 20 of a mobile crane 10 according to a preferred embodiment of the present invention is illustrated in a perspective view. The counterweight device 20 comprises a counterweight base plate 22, on which a further, plate-shaped counterweight element 24 can be placed in the exemplary embodiment shown here. In other embodiments, a plurality of plate-shaped counterweight elements 24 could also be stackable on the counterweight base plate 22.The coupling of the counterweight device 20 to the ballasting cylinders 18 is effected via connecting elements 30 which project vertically upwards from the counterweight base plate 22 and which have, at their upper ends, coupling sections 36 for reversibly coupling to retractable and extendable coupling pieces of the ballasting cylinders 18 (which are located in particular on the piston rods of the ballasting cylinders 18) and fastening means 34 for fastening the counterweight device 20 to the superstructure 14. The alignment or positioning of the counterweight device 20 in an assembly position on the ballast frame 16 for establishing the connection via the fastening means 34 can be effected via centering means of the connecting elements 30, which are shown in the exemplary embodiment discussed here, but are not provided with reference numerals.As can be seen in FIG. 2, the counterweight base plate 22 has a curved shape (however, this is not absolutely necessary) and is connected to two connecting elements 30 which project upwards perpendicularly from the counterweight base plate 22. The second counterweight element 24 is likewise plate-shaped and curved and has corresponding recesses 25 through which the connecting elements 30 project. The second counterweight element 24 is thus placed on the counterweight base plate 22 from above and is "threaded" onto the connecting elements 30 so that the end regions of the connecting elements 30 with the coupling sections 36 and fastening means 34 project above the second counterweight element 24. The second counterweight element 24 is in particular not bolted to the connecting elements 30, but rests on the counterweight base plate 22.The connecting elements 30, which could also be referred to as connecting blades or simply as blades, are in particular sheet metal constructions manufactured in one piece, which have a flat basic shape and are connected to the counterweight base plate 22. Since the connecting elements 30 in particular do not consist of a plurality of mutually connected parts but are formed in one piece, it is not necessary to provide welded connections which are to be produced in a complicated manner and have correspondingly high requirements.In the embodiment shown here, the connecting elements 30 are oriented parallel to one another and to the side edges of the counterweight base plate 22 (and of the second counterweight element 24). This results in a particularly favorable arrangement that facilitates the manufacture of the counterweight base plate 22 (and the second counterweight element 24). This is effected in particular by filling a steel box with solid metal blocks and subsequent filling with a binder. The parallel arrangement produces geometrically ideal regions for filling the steel box with metal blocks. This allows production in a simple and cost-effective manner. Alternatively, the counterweight base plate 22 and / or the second counterweight member 24 may be made of gray cast iron.In the exemplary embodiment discussed here, the mobile crane 10 according to the invention comprises a ballast frame 16 (cf. FIG. 3 ). The ballast frame 16 accommodates two hydraulic ballasting cylinders 18, the piston rods of which can be extended downward and have a coupling piece. The counterweight device 20 can be lifted via the ballasting cylinders 18 from a storage region on the upper side of the undercarriage 12 to the ballast frame 16 and connected thereto. Conversely, the counterweight device 20 can be placed on the storage area again by extending the ballasting cylinders 18 and can be loaded from there onto a transport vehicle, if appropriate by means of an auxiliary crane or the boom of the mobile crane 10.The connecting elements 30 each have, at their end regions spaced apart from the counterweight base plate 22, a coupling section 36 for coupling the connecting elements 30 and thus the counterweight device 20 to the ballasting cylinders 18. If, for the sake of simplicity, only one connecting element 30 is referred to below, both connecting elements 30 are naturally meant in this case.The coupling section 36 comprises a receptacle arranged centrally on the connecting element 30 in the form of an upwardly open, clamp-shaped recess 37, into which a specially shaped (in particular mushroom-shaped) end or coupling piece of the corresponding ballasting cylinder 18 can move laterally. In the final position, in which the counterweight device 20 can be reliably raised (=lock position), the coupling piece of the ballasting cylinder 18 is located completely within the recess 37 (likewise the second ballasting cylinder 18) assigned to the second connecting element 30, which coupling piece, by virtue of its shape, enables a positive raising of the counterweight device 20 by retraction of the ballasting cylinders 18, since the coupling piece cannot slide upward out of the recess 37.The counterweight device 20 according to the invention further comprises a carrier plate 40 with two lateral pivot wings or pivot carriers 42 which are each pivotably articulated on the carrier plate 40 about a vertical pivot axis 43. The support plate 40 has a shape substantially corresponding to that of the counterweight base plate 22, although this need not necessarily be the case. The pivot axes 43 of the pivot carriers 42 are located on the side of the carrier plate 40 opposite the superstructure pivot axis 13 in the erected state and are mounted in a connecting section 46 of the carrier plate 40 projecting laterally beyond the edge of the carrier plate 40 on both sides.The pivot carriers 42 can each be moved via a pivot drive 44 in the form of a hydraulic cylinder between a first position, in which the hydraulic cylinders 44 are maximally retracted and the pivot carriers 42 abut the carrier plate 40 (cf. FIG. 4 ), into a third position, in which the hydraulic cylinders 44 are maximally extended and the pivot carriers 42 are completely pivoted out (cf. FIG. 8 ). Upon extension of the hydraulic cylinders 44, the pivot beams 42 pivot laterally about their vertical axes 43. The hydraulic cylinders 44 are hingedly attached to both the support plate 40 and the respective pivot supports 42.The carrier plate 40 has two recesses 41 for receiving the connecting elements 30, which in the exemplary embodiment shown - following the tongue shape of the connecting elements 30 - have an elongate shape or are substantially slot-shaped. The carrier plate 40 is placed from above onto the stack of counterweight base plate 22 and second counterweight element 24 (alternatively, the stack could comprise a plurality of second counterweight elements 24), so that the sections of the connecting elements 30 protruding from the top of the second counterweight element 24 retract into the recesses 41 of the carrier plate. The carrier plate 40 is thus "threaded" onto the connecting elements 30 until only their fastening means 34 still look out of the carrier plate 40 at the top (cf. FIG. 3 ). After placement, the coupling sections 36 are located in particular within the recesses 41 of the carrier plate 40.The fastening means 34 of the connecting elements 30 are thus accessible after the support plate 40 has been placed on, so that the entire counterweight device 20 together with the counterweight base plate 22, the second counterweight element 24 and the support plate 40 (including. The pivot beam 42 and the first counterweight elements 50) can be bolted to the ballast frame 16. For this purpose, the fastening means 34 each comprise a bolt receptacle 35, the bolt receptacles 35 of the connecting elements 30 are brought together by lifting the counterweight device 20 with corresponding bolt receptacles of the ballast frame 16 (and optionally an adjoining region of the superstructure steel structure) and are bolted to the counterweight device 20 as soon as it is in an assembly position. As a result, the ballasting cylinders 18 are relieved during the crane operation.The connecting elements 30 have, in the region which is situated just above the surface of the second counterweight element 24, a plurality of bearing surfaces 31 which are arranged distributed around the connecting elements 30. The carrier plate 40 is designed such that it comes to rest on these bearing surfaces 31 and therefore does not contact the second counterweight element 24 after it has been set down. Thus, the carrier plate 40 introduces its weight directly into the connecting elements 30 via the bearing surfaces 31 and not into the plates 22, 24 beneath it. The carrier plate 40 can have counter bearing surfaces 47 (for example made of a different material than the remaining carrier plate 40) on its underside at the corresponding positions, which counter bearing surfaces contact the bearing surfaces 31.Further counterweight elements 50 (referred to herein as first counterweight elements 50) are stackable on the pivot beams 42 such that each pivot beam 42 carries its own counterweight stack 50. These are not restricted at the top, since in the connected state they are arranged outside the ballast frame 16 (the latter is arranged between the counterweight stacks 50, cf. FIGS. 4, 6, 8). In the exemplary embodiment shown here, the first counterweight elements 50 have a substantially triangular basic shape, just like the pivot carriers 42. Optionally, the first counterweight elements 50 can each have a central cutout 52 (cf. FIGS. 3 and 8 ), into which an elongate mounting device according to DE 20 2004 009 497 U1 can be pushed and locked therein by rotation, in order to be able to raise and move the first counterweight elements 50 with a crane. The pivot carriers 42 which can preferably be released from the carrier plate 40 can also have a corresponding recess 48 (cf. 2) in order to be able to lift or move them with such a mounting device.By pivoting the pivot carriers 42 together with the first counterweight elements 50 stacked thereon, the counterweight moment generated by the counterweight device 20 and the ballast radius of the superstructure 14 can be variably adjusted. The pivoting of the pivot carriers 42 via the pivot drives 44 is possible in a continuously variable manner and is therefore adaptable to the currently present load situation. Optionally, at least one sensor can be provided, which detects the outward pivoting state of the pivoting carriers 42 and forwards it to a crane controller for load torque limiting.After the support plate 40 has been placed on, it rests on the bearing surfaces 31 of the connecting elements 30, without being firmly connected to them. The carrier plate 40 (and the pivot carriers 42) are designed such that in the first position it rests stably on the support surfaces 31, i.e. the centre of gravity of the carrier plate 40 together with the pivot carriers 42 is located in plan view within the surface spanned by the support surfaces 31. Thus, the carrier plate 40 does not tilt aside in the first position. For the fixed or immovable connection of the carrier plate 40 to the connecting elements 30, the latter have connecting means in the form of bolt receptacles 32 below the fastening means 34. The carrier plate 40 likewise has corresponding connecting means, in particular corresponding bolt receptacles (not shown), through which corresponding bolts can be inserted after the bringing together or placing down. This can be done manually, whereby in particular corresponding recesses are present in order to be able to set the bolts manually. Alternatively, the carrier plate 40 can have a bolt plug-in device, by means of which bolts can be automatically pushed through the bolt receptacles of the carrier plate 40 and the connecting elements 30 after the placement, since these bolt receptacles are possibly difficult to access after the placement. By means of this connection, a fixed connection can thus be produced between the carrier plate 40 and the connecting elements 30. This connection can transfer forces and moments free of movement in the erected state.FIG. 3 shows a detail of the mobile crane 10 with the counterweight device 20, wherein only the steel frames of the superstructure 14 and of the undercarriage 12 are shown without further components such as chassis, boom etc. The counterweight device 20 is bolted to the ballast frame 16 and the pivot beams 42 are fully extended with their counterweight stacks 50 (third position). The ballast frame 16 carries a winch 17 and is bolted to the steel frame of the superstructure 14. One of the two ballasting cylinders 18 arranged laterally on the ballast frame 16, the piston rod of which is retracted, can be seen. It can also be seen that the fastening means 34 of the connecting elements 30 protrude at the top from the carrier plate 40, so that they can be bolted to the ballast frame 16. The carrier plate 40 is in the erected state between the ballast frame 16 and the second counterweight element 24.The coupling of the ballasting cylinders 18 to the connecting elements 30 is effected in particular by a rotation of the superstructure 14 about its axis of rotation 13. Therefore, the recesses 41 of the carrier plate 40, through which the connecting elements 30 project, are correspondingly widened at least in the region of the coupling sections 36, so that the ballasting cylinders 18 can be retracted downwardly alongside the connecting elements 30 into the recesses 41 until the coupling pieces are at the height of the receptacles 37 of the coupling sections 36. A coupling can then be produced by rotating the superstructure 14. In order that the coupling pieces of the ballasting cylinders 18 are not moved through the receptacles 37 but rather reach their correct locking position, the recesses 41 are preferably designed such that their lateral walls form corresponding mechanical stops for the coupling pieces of the ballasting cylinders 18. This prevents the ballasting cylinders 18 from passing over easily and effectively.FIGS. 4-9 show the counterweight device 20 in different positions of the pivot carriers 42, in a plan view (FIGS. 4, 6, 8) and in a side view (FIGS. 5, 7, 9).In FIGS. 4-5, the counterweight device 20 is still placed on the storage area of the undercarriage 12, i.e. is not yet mounted on the superstructure 14, and the pivot carriers 42 are in the first position. The hydraulic cylinders 44 are fully retracted and the pivot supports 42 bear against the support plate 40. In FIG. 5, the front counterweight stack 50 in the viewing direction is hidden in order to clear the view of the ballasting device which is located between the two counterweight stacks 50. The total center of gravity 80 of the counterweight device 20 is located in the range of action of the ballasting cylinders 18, i.e. in plan view within the surface spanned by the bearing surfaces 38 of the counterweight base plate 22 (cf. FIG. 5 and also FIG. 7, in which the bearing surfaces 38 are drawn in as triangles for illustration). As a result, in this configuration, the counterweight device 20 is stably standing on the storage area of the undercarriage 12 without tilting and can be securely ballasted.It can be seen in FIG. 5 that the unit consisting of the counterweight base plate 22, the second counterweight element 24 and the carrier plate 40 is designed such that the total height thereof is smaller than the distance between the storage region of the undercarriage 12 and the lower edge of the ballast frame 16, i.e. the upper edge of the carrier plate 40 lies below the lower edge of the ballast frame 16. This is clearly demonstrated in FIG. 10, wherein the line 70 drawn in identifies the height of the lowermost edge of the ballasting device or of the superstructure 14 in the region of the ballasting device. This line 70 lies above the carrier plate 40. the superstructure 14 can thus freely pivot over the carrier plate 40. In the case of a self-contained counterweight device 20, the ballast radius is minimized in the first position, with the result that the superstructure 14 requires a smaller space during rotation. At the same time, however, the counterweight moment is also reduced to the smallest possible extent.FIGS. 6 to 7 show the counterweight device 20 still placed on the storage area of the undercarriage 12. This is indicated in FIG. 6 by the drawn circular path 60 which represents the path of the rearmost edge of the ballast frame 16 when the superstructure 14 is rotated. The second position is in particular that position of the pivot carriers 42 in which the first counterweight elements 50 are located just outside the circular path 60.Due to the height of the unit consisting of the counterweight base plate 22, the second counterweight element 24 and the carrier plate 40, the superstructure 14 can be moved freely over the carrier plate 40 and the pivot carriers 42 during the setup if no first counterweight elements 50 are located on the pivot carriers 42. However, if it is intended to enable the first counterweight elements 50 to be placed on the pivot carriers 42 during the self-assembly of the mobile crane 10, the superstructure 14 must be able to rotate freely even if first counterweight elements 50 have already been stacked. For this purpose, a temporary hydraulic connection can be established with the pivot drives 44 and the pivot carriers 42 can be moved into the second position. In this position, the superstructure 14 can rotate freely and stack the first counterweight elements 50 on the pivot carriers 42 of the counterweight device 20 still placed on the undercarriage 12.As can be seen in FIG. 7, the total center of gravity 80 of the counterweight device 20 in the second position is still located (in plan view) within the outer contour of the counterweight base plate 22. As a result, the counterweight device 20 is still stably standing on the storage region of the undercarriage 12 even in this configuration without tilting.Finally, FIGS. 8-9 show the counterweight device 20 in a state mounted on the superstructure 14. In this case, the pivot carriers 42 are pivoted out into a third position, in which the hydraulic cylinders 44 are extended to the maximum and the pivot carriers 42 are pivoted out to the maximum. In this configuration, the ballast radius is maximized, as is the counterweight torque produced by the counterweight device 20.FIG. 9 shows a disturbance region of the undercarriage 12 which is elevated in comparison with the storage region and adjoins the storage region and, in this exemplary embodiment, represents a housing for an engine 15 and an exhaust gas aftertreatment device 19. This structure limits widening of the counterweight base plate 22 and the second counterweight member 24 to increase the counterweight moment. Due to the arrangement according to the invention of counterweight base plate 22, second counterweight element 24 and carrier plate 40, in the erected state of counterweight device 20, swivel carriers 42 are located above the upper edge of the housing of engine 15 and exhaust gas aftertreatment device 19.It can be seen in FIG. 8 that the connection between the connecting elements 30 and the carrier plate 40 via the connecting means 32 performs an essential function. In the third position, the total center of gravity 80 of the counterweight device 20 lies far outside the placement surface, i.e. the outer contour of the counterweight base plate 22 or of the support surfaces 38. Thus, another power transmission is necessary to receive the moment generated by the first counter weight members 50. This is effected by the solid connection 32.Optionally, the connecting elements 30 can have additional centering means in the region of the fastening means 34, by means of which the counterweight device 20 is automatically brought or precentred into the desired mounting position when the ballasting cylinders 18 are retracted. The centering means can be designed, for example, as projections or mandrels protruding upward in the longitudinal direction of the connecting element 30 and tapering and can interact with corresponding counter-centering means on the ballast frame 16 and, due to their beveled or conical contours, ensure automatic alignment of the counterweight device 20 when it is lifted on the ballast frame 16.An exemplary embodiment of a method according to the invention for setting up or mounting the counterweight device 20 according to the invention on the superstructure 14 of the mobile crane 10 is specified below.The ballast base plate 22 with the connecting elements 30 is placed on the placement area of the undercarriage 12 in a self-assembly manner (i.e. with the boom of the mobile crane 10).The second counterweight element 24 is placed on the counterweight base plate 22 (alternatively, the carrier plate 40 can be arranged directly above the counterweight base plate 22 or else a plurality of second counterweight elements 24 can be provided).If the pivot carriers 42 have been removed from the carrier plate 40 for transport, these are now mounted again on the carrier plate 40.The carrier plate 40 is placed above the second counterweight element 24 on the support surfaces 31 of the connecting elements 30, wherein the pivot carriers are in particular in the first position. The center of gravity 81 of the carrier plate 40 and the pivot carrier 42 (cf. FIG. 10 - not to be confused with the total center of gravity 80 of the counterweight device 20 when the carrier plate 40 is bolted to the connecting elements 30) lies in the first position within a surface which spans the bearing surfaces 31. Thus, the carrier plate 40 rests securely and stably on the support surfaces 31 without tilting. The superstructure 14 can freely pivot via the carrier plate 40 (cf. FIG. 10, horizontal line 70).The connection 32 between the connecting elements 30 and the carrier plate 40 is produced. From this moment on, the sole center of gravity 81 is no longer relevant, but rather the center of gravity 80 of the entire counterweight device 20 (cf. FIG. 5 ). The projected position of the center of gravity 80 is located within the surface spanned by bearing points of the counterweight base plate 22 on the undercarriage 12 or within the outer contour of the counterweight base plate 22.Optionally: if first counterweight elements 50 are required on the pivot carriers 42, the pivot carriers 42 must be pivoted into the second position (ballasting position) (cf. FIG. 6, circular path 60). For this purpose, it is necessary to establish a hydraulic and optionally electrical connection between superstructure 14 and pivot drives 44. The first counterweight elements 50 cannot be pivoted over by the superstructure 14. If the first counterweight elements 50 are not stacked up, this step is not necessary. The superstructure 14 is now freely rotatable in the second position of the pivot carriers 42 (for this purpose the supply from the superstructure 14 has to be released again beforehand) and the first counterweight elements 50 are stacked on the pivot carriers 42 in a self-assembly. Thereafter, the overall center of gravity 80 is still within the outer contour of the counterweight base plate 22, and when ballasting is to take place, the ballast frame 16 must be located between the counterweight towers 50. The hydraulic and optionally electrical connection is subsequently produced to the superstructure 14, for example when the bolt connection is produced between the counterweight device 20 and superstructure 14 or ballast frame 16.Alternatively, for counterweight stacking, the supply could also have been made to the undercarriage 12. Fewer clutch processes are necessary here, see for example DE 10 2016 005 505 A1.The pivot carriers 42 are preferably pivoted in again until the center of gravity 80 of the entire counterweight device 20 to be raised is positioned suitably with respect to the ballasting cylinders 18 (this need not necessarily correspond to the first position, but may be an intermediate position between the first and second positions) so that the counterweight device 20 can be reliably raised thereby and too large moments do not act on the ballasting cylinders 18.The superstructure 14 is rotated about the vertical axis of rotation 13 in order to bring the counterweight device 20 into a lifting position in which the coupling pieces of the ballasting cylinders 18 can be retracted into the recesses 41 next to the coupling portions 36 of the connecting elements 30.By rotating the superstructure 14 relative to the counterweight device 20, the coupling pieces of the ballasting cylinders 18 enter the receptacles 37 of the connecting elements 30 along circular paths. If necessary, locking can take place.The entire counterweight device 20 is now raised above the ballasting cylinders 18 until the counterweight device 20 reaches its mounting position on the superstructure 14 or ballast frame 16. Here, a precentration can optionally take place via centring means of the connecting elements 30.Finally, the bolt connections are produced between the fastening means 34 of the connecting elements 30 and corresponding fastening means on the ballast frame 16 (and optionally on a region of the superstructure steel frame adjoining the ballast frame 16). The counterweight device 20 is now firmly connected to the superstructure 14 and the mobile crane 10 is ready for operation.List of reference numbers:1 Mobile crane (prior art) 2 Counterweight base plate (prior art) 3 Counterweight plates (prior art) 4 Connecting means (prior art) 5 Counterweight (prior art) 10 Mobile crane 12 Undercarriage 13 Axis of rotation 14 Superstructure 15 Motor housing 16 Ballast frame 17 Winch 18 Ballasting cylinder 19 Exhaust gas aftertreatment device 20 Counterweight device 22 Counterweight base plate 24 Second counterweight element 30 Connecting element 31 Support surface 32 Connecting means (bolt receptacle) 34 Fastening means 35 Bolt receptacle 36 Coupling portion 37 Receptacle 38 Support surfaces 40 Carrier plate 41 Recess 42 Pivot carrier 43 Vertical axis 44 Pivot drive 46 Connecting portion 47 Counter support surface 48 Recess for mounting device 50 First counterweight element 52 Recess for mounting device 60 Circular path 70 Lower edge of ballasting device 80 Center of gravity counterweight device (support plate 40 bolted) 81 Center of gravity (substantially support plate 40 to pivot beams 42) 82 Projected center of gravity 83 Center of gravity (substantially of counterweight base plate 22, second counterweight member 24, and connecting members 30)

Claims

Mobile crane (10) comprising a mobile undercarriage (12), an undercarriage (14) rotatably mounted on the undercarriage (12) and a counterweight device (20) couplable to the undercarriage (14), which counterweight device comprises a counterweight base plate (22) and at least one connecting element (30) extending substantially perpendicularly to the counterweight base plate (22) and connected thereto for raising the counterweight device (20) and coupling the counterweight device (20) to the undercarriage (14), characterized in that the counterweight device (20) comprises a carrier plate (40) which can be connected to the at least one connecting element (30) above the counterweight base plate (22), wherein at least one pivot carrier (42) is mounted on the carrier plate (40) such that it can be pivoted about a vertical axis (43), on which at least one first counterweight element (50) can be stacked.Mobile crane (10) according to claim 1, wherein the at least one connecting element (30) is fixedly connected, in particular welded, to the counterweight base plate (22) or is accommodated in a recess of the counterweight base plate (22).Mobile crane (10) according to one of the preceding claims, wherein a ballasting device is provided on the superstructure (14), which is configured to lift the counterweight device (20) from a storage region of the undercarriage (12) and to store it thereon, wherein the at least one connecting element (30) has a coupling section (36) at an end opposite the counterweight base plate (22), via which coupling section a coupling with the ballasting device can be produced, wherein the ballasting device preferably comprises a ballast frame (16) which can be connected to the superstructure (14) via fastening means.Mobile crane (10) according to the preceding claim, wherein the ballasting device comprises at least one hydraulic ballasting cylinder (18) which can be releasably brought into engagement with the coupling section (36) of the at least one connecting element (30), wherein the coupling section (36) preferably comprises a receptacle (37) into which a coupling piece of the ballasting cylinder (18) can be moved, in particular by rotation of the superstructure (14) about its axis of rotation (13).Mobile crane (10) according to one of the preceding claims, further comprising at least one second counterweight element (24) which can be stacked on the counterweight base plate (22) and has at least one recess (25) through which the at least one connecting element (30) projects in the deposited state, wherein the second counterweight element (24) is arranged between the counterweight base plate (24) and the carrier plate (40) in the ballasted state.Mobile crane (10) according to one of the preceding claims, wherein the counterweight device (20) comprises at least two connecting elements (30) spaced apart from one another and arranged in particular at the same distance from the centre of gravity of the counterweight base plate (22) and / or at least two pivot carriers (42) mounted on the carrier plate (40) such that they can be pivoted about a vertical axis in each case.Mobile crane (10) according to one of the preceding claims, wherein the at least one connecting element (30) comprises one or more of the following elements: - a storage surface via which the counterweight base plate (22) rests on the connecting element (30) at least in the absence of an oblique position of the mobile crane (10) and initiates the weight force thereof, - a centring means by means of which the counterweight device (20) can be positioned automatically in an assembly position when being raised on the superstructure (14), - a fastening means (34) by means of which the counterweight device (20) can be detachably connected to the superstructure (14) in an assembly position, wherein the fastening means (34) preferably comprises a bolt receptacle (35) for producing a bolt connection to the superstructure (14).Mobile crane (10) according to one of the preceding claims, wherein the at least one pivot carrier (42) is continuously pivotable relative to the carrier plate (40) via a pivot drive (44), in particular a hydraulic cylinder, wherein the pivot angle of the pivot carrier (42) is preferably detectable via at least one sensor.Mobile crane (10) according to one of the preceding claims, wherein the at least one connecting element (30) has a support surface (31) on which the carrier plate (40) can be placed, in particular in such a way that the weight force of the placed carrier plate (40) is introduced only into the at least one connecting element (30) and not into the counterweight base plate (22) or a second counterweight element (24) placed thereon.Mobile crane (10) according to one of the preceding claims, wherein the carrier plate (40) comprises at least one recess (41) through which the at least one connecting element (30) projects in the connected state, wherein the end of the connecting element (30) projecting through the carrier plate (40) preferably comprises a fastening means (34) via which the counterweight device (20) can be detachably connected to the superstructure (14), wherein the recess (41) is preferably designed such that a coupling piece of a ballasting cylinder (18) of the superstructure (14) can be positioned within the recess (41) next to a coupling section (36) of the connecting element (30) and can be moved into a receptacle (37) of the coupling section (36) by rotation of the superstructure (14) about its vertical axis of rotation (13).Mobile crane (10) according to one of the preceding claims, wherein the carrier plate (40) and the at least one connecting element (30) each have connecting means (32) for producing a releasable connection, in particular a bolt connection, to one another.Mobile crane (10) according to one of the preceding claims, wherein the at least one first counterweight element (50) can be moved by pivoting the pivoting carrier (42) from a first position resting against the carrier plate (40) into a second position in which the superstructure (14), when the connection to the counterweight device (20) is released, can be rotated relative to the latter without colliding therewith, wherein the at least one first counterweight element (50) preferably has a substantially triangular basic shape.The counterweight device (20) for a mobile crane (10) according to any one of the preceding claims, preferably further comprising at least one first counterweight element (50) stackable on the pivot support (42) and / or at least one second counterweight element (24) stackable on the counterweight base plate (22).Method for mounting the counterweight device on the superstructure (14) of a mobile crane (10) according to one of claims 1 to 12, comprising the following steps: - placing the counterweight base plate (22) on a storage region of the undercarriage (12), in particular by means of a boom fastened to the superstructure (14) of the mobile crane (10), - connecting the carrier plate (40) to the at least one connecting element (30), - lifting the counterweight device (20) via the at least one connecting element (30), - establishing a connection between the at least one connecting element (30), in particular a fastening means (34) of the connecting element (30) protruding through the carrier plate (40), and the superstructure (14), in particular a ballasting device of the superstructure (14).Method according to the preceding claim, wherein the mobile crane (10) is formed at least according to claims 9 to 11 and the step of connecting the carrier plate (40) to the at least one connecting element (30) comprises the following steps: - guiding the carrier plate (40) to the at least one connecting element (30), in particular by means of the boom of the mobile crane (10), - introducing the at least one connecting element (30) into the corresponding recess (41) of the carrier plate (40), - placing the carrier plate (40) on the support surface (31) of the at least one connecting element (30), so that the carrier plate (40) rests completely thereon, - connecting the carrier plate (40) to the at least one connecting element (30) via the connecting means (32).

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