Mobile crane with adjustable counterweight device

Abstract

To provide a counter weight for a mobile crane, which can change counter torque during an operation and has a small number of counter weight elements.SOLUTION: This mobile crane comprises: a movable lower travel body; an upper turning body 14 rotated about a rotation longitudinal axis 13; a counter weight base plate 52; and at least one connection element 70 that extends from the counter weight base plate to lift and connect a counter weight device 50 to a ballast device. A distance of the counter weight device 50 from the rotation axis 13 of the upper turning body can be adjusted by at least one first arm 31. The first arm 31 in a ballast state is connected to the counter weight base plate 52 via a turnable connection element, and the counter weight base plate can be adjusted in radial linear motion with respect to the rotation axis of the upper turning body.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] A mobile crane typically has an undercarriage with a wheeled or crawler chassis, a rotating upper unit rotatably attached to the undercarriage about a vertical axis, a boom rotatably connected to the rotating upper unit, and a counterweight arrangement, also known as rotating upper unit ballast. At all positions on the rotating upper unit, the counterweight applies a counter torque to the load torque via a lever arm and therefore rotates with the rotating upper unit.

[0003] While small mobile cranes are often fully equipped for use on construction sites as so-called taxi cranes, larger mobile cranes cannot even do this on public roads and require all or part of the crane components, and in particular the counterweight assembly, to be disassembled and reassembled on-site for transport over public roads. The counterweight assembly of a crawler crane also typically needs to be disassembled for transport and adapted to the rotating upper bed at the location of use.

[0004] Therefore, it is known from the prior art to provide a counterweight base plate with connecting elements for detachable connection with the upper rotating body, on which counterweight elements can be stacked. For this purpose, the upper rotating body is equipped with a ballast device that can pick up the counterweight arrangement, which includes the counterweight base plate and the counterweight elements stacked thereon with the connecting elements, from the floor or from a storage area on the undercarriage and lift the counterweight arrangement up to the upper rotating body for assembly. For disassembly, the counterweight base plate with the counterweight elements can be repositioned on the floor or the undercarriage. For this purpose, the ballast device usually includes one or more hydraulic ballast cylinders that extend downward, engage with the connecting elements of the counterweight arrangement, and, upon contraction, lift the counterweight arrangement up to the upper rotating body.

[0005] In the prior art, cylindrical or flat receiving tubes are used as connecting elements, which are fixedly connected, e.g., welded, to the counterweight base plate and protrude vertically upward from the counterweight base plate. The counterweight elements have corresponding recesses through which the connecting elements protrude, so that when stacked, the ballast cylinders can engage with the receptacles of the connecting elements from above, for example, in accordance with the rotational movement of the upper bed.

[0006] To assemble the counterweight device, the counterweight device is typically placed in a storage area of ​​the undercarriage, and the counterweight elements are stacked on the counterweight base plate. The upper rotating body rotates with its ballast device on the stacked counterweight device, and a ballast cylinder pulls the counterweight device to the upper rotating body using a connecting element. This assembly method limits the size of the volume that can be installed for the counterweight device. Specifically, the counterweight device cannot freely extend far from the upper rotating body's longitudinal axis of rotation or the axis of rotation of the upper rotating body. However, because the undercarriage typically has other components such as a cab, an engine housing, exhaust gas aftertreatment components, or similar elements, the counterweight device cannot extend into this area. The counterweight device also cannot extend close to the upper rotating body's longitudinal axis of rotation because the steel structure of the upper rotating body is located at that axis. If it is possible to further increase the mass of the counterweight, this can only be achieved by increasing the specific gravity of the counterweight elements while maintaining the same volume. However, this makes the manufacture and procurement of the counterweight elements complex and expensive.

[0007] German Utility Model No. 202014008661 discloses that the distance between the ballast cylinder and the rotation axis of the upper rotating body can be varied to increase the counterweight torque. This distance can be fixed before setting up the counterweight. However, the disadvantage of this solution is that the counterweight radius cannot be changed during crane operation, and therefore it is not possible to adapt it to the prevailing spatial conditions at the construction site, for example, during certain rotational movements. In addition, mobile cranes with a variable support base have an additional tilt criterion.

[0008] Other solutions, such as that in DE 10 2016 009 013, use a swiveling counterweight base plate. However, assembling such a counterweight device is complicated because the counterweight device carries its own ballast cylinder and presses itself against the upper rotating bed from below. Therefore, the hydraulic connection of the counterweight device to the ballast cylinder must be established before setting up the counterweight. Furthermore, the counterweight device must be securely, safely, and stably attached to the ballast cylinder so that it does not tip over when being pushed up. In addition, such a solution is more suitable for larger mobile cranes that use towers of stacked counterweight elements, where the use of standardized counterweight elements becomes more valuable. Summary of the Invention [Problem to be solved by the invention]

[0009] Against this background, it is an object of the present invention to provide a counterweight arrangement for a general mobile crane, in which the generated counter torque can be varied during operation and which is particularly suitable for smaller mobile cranes with a reduced number of counterweight elements. [Means for solving the problem]

[0010] According to the invention, this object is achieved by a mobile crane having the features of claim 1. Advantageous embodiments of the invention emerge from the dependent claims and the following description.

[0011] The present invention provides a mobile crane comprising a movable undercarriage, a rotating upper body attached to the undercarriage, the rotating upper body rotatable about a longitudinal axis of rotation of the rotating upper body, and a counterweight device. Specifically, a boom, e.g., a telescoping boom, moves up and down and is articulated relative to the rotating upper body. The rotating upper body comprises a ballast device to which the counterweight device can be removably coupled to generate a counter torque that reacts with a lifted load during operation. The counterweight device comprises a counterweight base plate and at least one connection element for lifting the counterweight device and connecting it to the ballast device of the rotating upper body. The at least one connection element extends from the counterweight base plate and is connected to the ballast device. Specifically, the connection element extends essentially perpendicular to the counterweight base plate. The ballast device comprises at least one first arm pivotally attached to the rotating upper body about the longitudinal axis of rotation, the distance from the counterweight device to the rotation axis of the rotating upper body being adjustable in a ballast state. The counterweight device is directly or indirectly connected to the at least one first arm so that movement of the first arm results in movement of the counterweight device.

[0012] According to the present invention, the first arm is connected to the counterweight base plate in a ballast state via a pivotable connecting element. If there are multiple first arms, each first arm is connected to a corresponding connecting element. At least one connecting element is pivotally attached to an associated first arm and counterweight base plate such that simultaneous pivoting of the first arm and connecting element can adjust or change the radial linear movement of the counterweight base plate relative to the rotation axis of the upper rotating bed.

[0013] The combination of the first arm and the connecting element, both of which are pivotable according to the present invention, makes it possible to change the counterweight radius by linearly moving the counterweight device in a radial direction relative to the rotational axis of the rotating superstructure, i.e., parallel to the longitudinal direction of the rotating superstructure, rather than by pivoting the counterweight in a circular path. This allows for flexible adjustment of the counter torque generated by the counterweight device during crane operation, and in particular, does not require any additional space on the sides of the rotating superstructure or the counterweight device, since the counterweight does not pivot to the sides. This facilitates work, in particular in enclosed construction site environments.

[0014] Furthermore, because the counterweight radius is adjusted during ballast operation and not during counterweight setup, the undercarriage only requires a single location device or a single storage area for the counterweight device, and therefore the undercarriage can have an optimized space-saving design.

[0015] Preferably, the at least one first arm is actively swivellable via at least one actuator, in particular a hydraulic cylinder. Adjustment of the counterweight device by means of the at least one actuator can be preferably performed in a centralized manner by a crane control system, to which an operator can preferably make corresponding inputs from the cab.

[0016] For simplicity's sake, when referring hereinafter simply to a "connection element," this should be understood as at least one connection element (i.e., including any other existing connection elements). In addition, absolute descriptions such as "vertical" and "horizontal" always refer to the mobile crane standing on a flat, horizontal surface.

[0017] Preferably, the at least one connecting element is specifically designed as a sheet metal structure having a substantially flat shape, which is easier to manufacture than, for example, a cylindrical support tube and can be manufactured with a thickness suitable for withstanding the various loads acting along and across its longitudinal axis.

[0018] The connecting element can have a stop element for joining a stop means (e.g., a chain or rope) of a hoist for lifting the counterweight base plate. This means that the counterweight base plate with the connection element can be lifted, for example, by an assist crane or a mobile crane, to allow it to set up itself and be located on a storage area of ​​the undercarriage. Preferably, the stop element is formed by a recess in the connecting element. Hook elements, protrusions, etc. are also envisaged for joining the stop means.

[0019] In one possible embodiment, the counterweight device may comprise two spaced apart connection elements for connecting the counterweight device to the ballast device. The ballast device of this embodiment therefore has two pivotable first arms that pivot together or synchronously to adjust the distance from the counterweight device to the rotation axis of the upper rotating body. The use of multiple connection elements provides a stable connection of the counterweight device to the upper rotating body. Preferably, exactly two connection elements are provided.

[0020] In particular, the connecting elements can be positioned at the same distance from the center of gravity of the counterweight base plate or from the longitudinal axis of the rotating upper body. The counterweight arrangement is preferably symmetrical about a vertical plane passing through the longitudinal axis of the rotating upper body.

[0021] In another possible embodiment, the first arms may be arranged on the sides of the ballast devices, specifically on a ballast frame connected to or formed on the upper rotating body, and the first arms may be swiveled in opposite directions, i.e., one first arm swivels clockwise while the other first arm swivels counterclockwise, for linear adjustment of the distance of the counterweight device from the rotation axis of the upper rotating body.

[0022] The synchronized, actuator-based adjustment of the first arm can be implemented in a variety of ways.

[0023] In one possible embodiment, each of the first arms can pivot via its own hydraulic cylinder. In this case, a suitable synchronization of the pivoting movements must be ensured. This can be achieved by synchronizing the hydraulic cylinders with the associated control system. This can be achieved, for example, by length sensors in the cylinders, which send a signal to the control system, which controls the hydraulic cylinders to synchronize accordingly via electrically operated valves. In this case, the number of stationary load cases can be reduced in this way (no asymmetry needs to be estimated).

[0024] In an alternative embodiment, only one of the first arms may be pivotable via a hydraulic cylinder, and the first arms may be mechanically coupled to one another by a gear transmission so that when the hydraulic cylinder is actuated, the first arms pivot synchronously. In this case, the term "gear transmission" means that at least two gear wheels are provided. These may be coupled to one another by further gear wheels or by connecting means such as a chain. In the latter case, a chain transmission may also be referred to.

[0025] The mechanical coupling of the first arms means that synchronized control of multiple actuators is not required. The gear transmission preferably comprises gear wheels connected to rotatably fixed first arms that are mechanically coupled to each other by connecting means. The coupling is not direct, since otherwise the first arms would move in the same direction. Therefore, at least one additional gear wheel is provided to reverse the direction of rotation of one of the first arms. In particular, the additional gear wheel is freely rotatable on the upper rotating body and meshes with a rotatably fixed gear wheel of one of the first arms. In particular, the rotatably fixed gear wheel is arranged collinearly with the axis of rotation of the arm.

[0026] The connecting means is preferably a chain, so that the synchronous drive is designed as a chain transmission or chain drive, but a belt or one or more gear wheels can also be provided as connecting means.

[0027] When the hydraulic cylinder is actuated, a gear wheel arranged on this first arm rotates with the arm, thereby moving the connecting means, which in turn moves a gear wheel mounted freely rotatably on the upper rotating body, which in turn meshes with a gear wheel fixed to the other first arm, resulting in a synchronized counter-rotating pivoting movement of both arms.

[0028] Another possible embodiment provides that the ballast unit is designed to lift the counterweight unit from a storage area of ​​the undercarriage and place it thereon. The storage area can be located behind the driver's cab of the undercarriage. At least one connection element has, at its end opposite the counterweight base plate (i.e., facing the upper rotating body or the ballast unit), a coupling portion through which a removable mechanical connection with the ballast unit can be made. The coupling portion can have a receptacle into which a lifting device of the ballast unit, in particular a ballast cylinder, can be inserted to establish a connection for lifting the counterweight unit.

[0029] In a further alternative embodiment, the ballast unit may comprise at least one hydraulic ballast cylinder removably engageable with a coupling part of the at least one connecting element. The coupling part specifically comprises a receptacle into which the coupling part of the ballast cylinder can be inserted by rotating the upper body about the rotation axis of the upper body. Specifically, the ballast cylinder has a piston rod that can extend downward from the ballast unit and has a coupling part at its end. The coupling part can be part of the piston rod of the ballast cylinder, i.e., it can be formed as one part together with the piston rod, or as a separate component connected to the piston rod.

[0030] In particular, the connecting part is open on the top and on at least one side. The receptacle can be designed to allow the ballast cylinder to be pushed in sideways (for example, following a circular motion) and, when connected, to actively block the vertical movement of the ballast cylinder from the recess. In the raised state, the counterweight device can hang on or hang from the connecting part of at least one ballast cylinder via the recess of the at least one connecting element.

[0031] The connecting piece can be fixed in the recess by, for example, a special locking device. Alternatively, or in addition, the locking mechanism can simply be a mechanical stop that blocks any further movement of the connecting piece relative to the connecting part.

[0032] In a further alternative embodiment, at least one of the receptacle and the connecting piece may have a rounded, e.g., crown-shaped, profile that allows articulation of the connecting piece within the receptacle in the presence of a load. Such a connection allows the connecting element to pivot relative to the ballast cylinder with various degrees of freedom, for example, to counteract the movement of the ballast cylinder along a circular path when the first arm pivots, allowing linear displacement of the counterweight device.

[0033] In a further possible embodiment, the ballast cylinder comprises a cylinder jacket and a piston removable within the cylinder jacket, the piston having a piston rod at its free end where the connecting piece is located, the piston being mounted in the cylinder jacket so as to be rotatable about the longitudinal axis of the piston rod, such that the connecting piece located in the receptacle of the connecting element can rotate relative to the corresponding first arm during the pivoting movement of the first arm, ideally without rotating relative to the receptacle of the connecting element, thereby reducing or avoiding frictional forces resulting from relative movement within the receptacle.

[0034] The ballast cylinder is operable by a hydraulic system, wherein the ballast cylinder and hydraulic system are designed such that in a ballast state, in a fixed mode, the piston rod is blocked from extending and rotating, while in an adjustment mode, the piston rod can rotate in the same extended position relative to the cylinder jacket.

[0035] In the fixed mode, the ballast cylinder is therefore hydraulically isolated, while in the adjustment mode, the piston rod can rotate about its longitudinal axis to adjust the counterweight radius. In the adjustment mode, the piston rod is preferably extended further than in the fixed mode. The counterweight device is preferably pressed against the upper rotating body by the ballast cylinder and fixed there by hydraulic isolation (fixed mode). Hydraulic isolation can be performed, for example, after a specified contact pressure has been reached. An additional mechanical connection, for example, by one or more bolt connections, can optionally be provided. Due to the resistance created by the hydraulic isolation, the ballast cylinder must first be loosened to adjust the counterweight radius. If the counterweight device is adjustable, the hydraulic isolation is loosened and the piston rod of the ballast cylinder is slightly extended. Since the piston rod can rotate freely relative to the cylinder, movement relative to the attachment of the connecting element can be avoided when the first arm pivots.

[0036] In another possible embodiment, at least one second counterweight element is provided that can be stacked on the counterweight base plate, and the second counterweight element has at least one recess from which at least one connecting element protrudes in the deployed state. Specifically, the second counterweight element has a flat shape. A plurality of second counterweight elements are provided that can be stacked on the counterweight base plate.

[0037] Specifically, the connection element has the aforementioned connection portion for connecting with the corresponding connection part of the ballast cylinder. Preferably, the connection portion, or its receptacle, is arranged to lie in the recess of the second counterweight element in the connected state. Preferably, the receptacle is designed so that the connection part of the ballast cylinder can be located in the recess next to the connection portion of the connection element and can be accommodated in the connection portion or its receptacle by rotating the upper body about its longitudinal axis of rotation. The ballast cylinder moves laterally in a circular path towards the receptacle. Therefore, the corresponding receptacle of the second counterweight element must be wider to allow such a circular movement when connecting the ballast cylinder to the connection element.

[0038] The receptacle of the second counterweight element can have a mechanical stop against which the connecting part of the ballast cylinder strikes in the fixed position where the ballast cylinder and the connecting element are correctly connected to each other. The stop can be formed by the wall of the receptacle itself, which results in a particularly simple design. Alternatively, the stop can also be realized by a separate component arranged in the receptacle.

[0039] In a further possible embodiment, a measuring device for detecting the ballast state of the mobile crane is also provided, which is transmitted to the control unit of the mobile crane, in particular to the load torque limiter, so that the ballast state can be continuously monitored and any possible tilting of the crane can be recognized and prevented at an early stage. The measuring device preferably comprises at least one sensor capable of detecting the instantaneous swing angle of the at least one first arm.

[0040] In a further possible embodiment, at least one first arm of the ballast device may be articulatedly connected to a second arm, the second arm being attached to the first arm so as to be pivotable about a longitudinal axis of rotation. If a plurality of first arms are provided, each of these first arms is connected to a second arm so as to be rotatable about a longitudinal axis of rotation. In this case, at least one connection element of the counterweight device may be connected to at least one second arm. The counterweight device is therefore connected to the second arm rather than the first arm. The connection is preferably achieved by the above-mentioned ballast cylinder. In this case, at least one second arm has a ballast cylinder for raising the counterweight device above the at least one connection element and connecting the counterweight device to the ballast device.

[0041] In a further alternative embodiment, the first and second arms may be connected to each other such that when the first arm is pivoted about its axis of rotation, the second arm connected to the first arm automatically pivots about its axis of rotation. Thus, the two arms are mechanically connected to each other and perform synchronized pivoting motions, specifically in opposite directions, about their respective axes of rotation. The arm movements are preferably synchronized such that the pivot angles or angular velocities are fixed relative to each other. This allows the two arms to coordinate such that each arm performs a pivoting motion while the ballast cylinder disposed on the second arm performs a linear motion. When two connecting elements, and thus two pairs of first and second arms, are provided, this results in linear motion of the counterweight device parallel to the longitudinal axis of the superstructure, with the individual motion of each arm occurring on a circular path.

[0042] Synchronization of the coupled first and second arms can occur in a variety of ways.

[0043] In another possible embodiment, the first and second arms may be connected to each other via a second hydraulic cylinder, where the first hydraulic cylinder that pivots the first arm relative to the upper rotating body and the second hydraulic cylinder that pivots the second arm relative to the first arm are synchronized and controlled so that the angular velocities of the first and second arms are in a fixed ratio to each other during pivoting. Coordination or synchronization of the two arms is thus achieved here by synchronizing multiple hydraulic cylinders.

[0044] In an alternative embodiment, the first and second arms may be mechanically coupled to each other by a gear transmission so that the first and second arms rotate synchronously when the hydraulic cylinder that rotates the first arm relative to the upper rotating body is activated. Similar to the mechanical coupling of the two first arms described above, the first and second arms may also be synchronized by a mechanical coupling. The gear transmission that mechanically synchronizes the first and second arms preferably comprises a first gear wheel rotatably fixedly connected to the upper rotating body and a second gear wheel rotatably fixedly connected to the second arm, which are connected to each other by a connecting means, specifically a chain. When the second arm rotates relative to the first arm, the second gear wheel rotates together with the second arm. Again, instead of a chain, a belt or an additional gear wheel (i.e., at least one additional gear wheel) may be used.

[0045] Specifically, the second gear wheel is disposed collinearly with the rotation axis of the second arm and moves with the first arm when the second arm pivots, causing the second gear wheel to rotate relative to the upper pivot body. Because the entire first gear wheel is rotatably fixed and joined and connected by a connecting means, when the first arm pivots in one rotational direction, the second arm, which is rotatably fixed to the second gear wheel, automatically rotates in the opposite rotational direction.

[0046] If two first arms are provided, they can be mechanically coupled to the corresponding second arms by gear drives, as described above, on the one hand, and to each other on the other hand. Alternatively, all or some of the arms can be pivoted by means of hydraulic cylinders. In particular, the following combinations are possible: The first arms are mechanically connected to each other and also to the corresponding second arms by means of a gear transmission, i.e. only one of the first arms is swivellable by means of a hydraulic or adjusting cylinder, while the other one of the first arms and the two second arms move automatically by means of mechanical gears. The first arms are mechanically coupled to one another by a gear transmission, while the second arms are moved relative to one another by hydraulic cylinders. However, this variant is less preferred, since it is necessary to coordinate the movement of the second arms with the first arms in a complex manner by appropriately controlling the various hydraulic cylinders. Both first arms can be pivoted by their own hydraulic cylinders, where they are matched to each other as described above, and the first arm is connected to the second arm by a gear transmission. Both first arms can be pivoted by their own hydraulic cylinders, where the second arms are also each moved by a hydraulic cylinder, i.e. at least four hydraulic cylinders need to be coordinated.

[0047] In the above-described embodiment, the linear motion of the counterweight base plate is achieved by converting the pivotal motion of the first arm (i.e., the circular orbital curve of the end of the first arm) into a linear motion of the free end of the second arm by synchronizing the pivotal motion with the second arm. Therefore, here, the second arm (or second arm) represents the above-described pivotable connecting element, and both the pivotal motion of the first arm and the pivotal motion of the connecting element occur around the longitudinal axis of rotation.

[0048] A further solution for achieving a linear movement of the counterweight base plate parallel to the longitudinal axis of the upper swivel bed is realized in a possible alternative embodiment in which at least one connecting element of the counterweight device is pivotally connected to the counterweight base plate. The at least one connecting element can be connected to the at least one first arm, in particular by a ballast cylinder arranged on the first arm. A second pivoting arm is not provided here, but the counterweight device is directly connected to the at least one first arm.

[0049] In this embodiment, the pivoting movement of the first arm is not achieved by the second arm rotating in the opposite direction, but by the fact that at least one connecting element is pivotally mounted and can therefore be turned substantially to the side as the first arm pivots, in this case the at least one connecting element is itself a pivotable linking element and is connected to the counterweight base plate.

[0050] In a further possible embodiment, as described above, two connection elements are provided, each connected to the counterweight base plate so as to pivot about a horizontal pivot axis. When pivoting the first arm for linear adjustment of the counterweight device, the connection elements pivot laterally, specifically perpendicular to the direction of movement of the counterweight device or the longitudinal axis of the upper rotating body, to offset the circular movement of the first arm. Adjusting the counterweight radius therefore involves a combination of a pivoting movement about the vertical axis of rotation and a further pivoting movement about the horizontal axis of rotation.

[0051] As mentioned above, both first arms can each be driven by a hydraulic cylinder, or the first arms can be mechanically linked to each other so that only one of the first arms needs to be driven by an actuator or hydraulic cylinder.

[0052] Pivoting of the connecting element relative to the first arm also necessarily results in relative movement, in particular between the connecting part of the ballast cylinder located at the end of the first arm and the receptacle of the connecting part of the connecting element. This relative movement can be counteracted in various ways.

[0053] In a possible embodiment, the connecting element may comprise a base body pivotably connected to the counterweight base plate and to the end of the counterweight base plate facing the first arm or the ballast device, respectively, and the swivel body may be pivotally joined and have a coupling part by which the connection of the ballast device to the first arm can be established. The swivel body is preferably pivoted relative to the base body about a horizontal pivot axis to compensate for the tilted position of the connecting element and thereby ensure a constant alignment or tilt of the coupling part relative to the first arm. In particular, as mentioned above, the coupling part comprises a receptacle for connection with the ballast cylinder of the first arm.

[0054] Alternatively, as mentioned above, a rounded or crown-shaped connection between the receptacle and the connecting piece can be used to minimize friction of the connecting piece within the receptacle. In such a design, the connecting element does not need to have a pivot piece.

[0055] In a further possible embodiment, each connection element may be compressively stressed to a vertical or inwardly pivoted base position by a return element, in particular a spring, which compresses the connection element inward so that when the counterweight device is adjusted, the connection element pivots or "turns" outward against the restoring force of the return element. The return element may be designed as a very strong spring, for example as a disk spring.

[0056] In a further possible embodiment, the connection element may be connected to the counterweight base plate and be swiveled in both directions at a maximum swivel angle relative to the vertical. The maximum swivel angle or amount is preferably less than 20° (i.e., -20°<α<20°), particularly preferably less than 15° (i.e., -15°<α<15°). In this embodiment, the recesses of any other counterweight elements arranged on the counterweight base plate, into which the connection element protrudes, must be appropriately widened to prevent the connection element from colliding with the recess walls during the above-mentioned swivel movement.

[0057] Further features, details and advantages of the invention emerge from the following exemplary embodiments, which are explained with the aid of the drawings. [Brief explanation of the drawings]

[0058] [Figure 1] 1 shows a perspective view of an upper rotating body of a mobile crane according to a first embodiment of the present invention. [Figure 2] FIG. 10 is a perspective view of an upper rotating body of a mobile crane according to a second embodiment of the present invention. [Figure 3] FIG. 10 is a perspective view of an upper rotating body of a mobile crane according to a third embodiment of the present invention. [Figure 4] 10A-10D show perspective views of embodiment 3 in different positions when adjusting the counterweight device. [Figure 5] 10A-10D show perspective views of embodiment 3 in different positions when adjusting the counterweight device. [Figure 6] 10A-10D show perspective views of embodiment 3 in different positions when adjusting the counterweight device. [Figure 7] 10A-10D show perspective views of embodiment 3 in different positions when adjusting the counterweight device. [Figure 8] 10 shows a schematic diagram of an upper rotating body of a mobile crane according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0059] 1 shows a perspective view of the superstructure 14 of a mobile crane 10 according to a first embodiment of the present invention, in which the steel structure of the superstructure 14 is shown without any covers and without the boom (specifically, the telescoping boom) to provide a clearer view of the components involved here. The superstructure 14 is pivotally mounted to a mobile undercarriage (also not shown) about the superstructure's longitudinal axis of rotation 13.

[0060] At the rear of the upper bed 14, the upper bed 14 has a ballast system 20 comprising a ballast frame 22 to which a counterweight system 50, also known as upper bed ballast, can be removably connected to counteract the impact of a load being lifted by the boom and prevent the mobile crane 10 from tipping over. The counterweight system 50 comprises a counterweight base plate 52 upon which one or more counterweight plates can be positioned or stacked (for clarity, only the counterweight base plate 52 is shown in the drawings). The ballast frame 22 can carry a winch 24.

[0061] In the exemplary embodiment discussed herein, the ballast unit 20 includes two hydraulic ballast cylinders 26 for picking up or placing the counterweight unit 50 from or into a storage area on the undercarriage. After lifting the counterweight unit 50 onto the ballast frame 22, they can either be bolted together, or the ballast cylinders 26 press the counterweight unit 50 against the ballast frame. In the latter variant, implemented in the exemplary embodiment shown herein, the ballast cylinders 26 are hydraulically cut off when a predetermined contact pressure is reached, thereby firmly holding the counterweight unit 50 on the upper rotating bed 14. The ballast cylinders 26 include pistons replaceably mounted within cylinder jackets and have piston rods that project downward toward the undercarriage or counterweight unit 50.

[0062] To install the counterweight unit 50, the counterweight unit 50 is stacked on the undercarriage. The upper rotating body 14 rotates with its ballast unit 20 via the counterweight unit 50 and couples to the counterweight unit 50, after which the ballast cylinders 26 retract the counterweight unit 50 into the upper rotating body 14, where it is retained during crane operation.

[0063] The counterweight device 50 is connected to the ballast cylinder 26 via two connecting elements 70 protruding vertically upward from the counterweight base plate 52, and their upper ends facing away from the counterweight base plate 52 have connecting portions for reversible connection to the retractable and extendable connecting parts 27 of the ballast cylinder 26, which connecting portions are located at the lower ends of the piston rods of the ballast cylinders 26. Other counterweights that can be placed on the counterweight base plate 52 have corresponding recesses into which the connecting elements 70 protrude. Thus, other counterweights are placed on the counterweight base plate 52 from above and "plugged" into the connecting elements 70, in particular so that the end regions of the connecting elements 70 with the connecting portions protrude above or otherwise remain accessible.

[0064] In the exemplary embodiment shown herein, the connection element 70 is manufactured as a sheet metal structure having a flat basic shape and can therefore also be called a connection sword, or simply a sword. The connection part of the connection element 70 is a centrally located, upwardly opening receptacle with a clamp-shaped receptacle 76, in which a specially shaped (specifically, mushroom-shaped) connection part 27 of the corresponding ballast cylinder 26 can move laterally. In the final position where the counterweight device 50 is safely raised, the connection part 27 is completely located within the receptacle 76, and due to its shape, the connection part 27 cannot slide upward from the receptacle 76. Therefore, by retracting the ballast cylinder 26, the counterweight device 50 can be actively raised. When the upper rotating body 14 rotates about its longitudinal axis of rotation 13, the extended ballast cylinder 26 is connected to the connection element 70.

[0065] In order to be able to adjust the distance of the counterweight unit 50 from the upper rotating body's axis of rotation 13 along the upper rotating body's longitudinal axis (i.e., radially or perpendicularly to the upper rotating body's axis of rotation 13) during crane operation, i.e., in a ballast condition, the ballast frame 22 in all of the exemplary embodiments discussed herein has two pivoting arms, referred to herein as first arms 31, each connected to the ballast frame 22 and pivoting about a first longitudinal axis of rotation 33. The counterweight unit 50 is directly or indirectly connected to the ballast unit 20 by the pivotable first arms 31, which pivot about the longitudinal axis of rotation 33 to vary the counterweight radius. Since the end of the first arm 31 moves along a circular path, further pivotable connecting elements are provided according to the invention, which are arranged between the counterweight base plate 52 and the first arm 31 and which ensure an overall linear movement of the counterweight arrangement 50 along the longitudinal axis of the upper rotating body, despite the pivoting movement of the first arm 31.

[0066] 1, this linear movement is made possible by the fact that a further pivoting arm, designated as second arm 32, is articulated to each end of the first arm 31, the second arm 32 being connected to the first arm 31 so as to pivot about a second longitudinal axis of rotation 34. In this embodiment, the second arm 32 represents the aforementioned pivotable connecting element. The ballast cylinder 26 is located at the free end of the second arm 32, which allows the connection of the counterweight device 50 to the connecting element 70.

[0067] When the counterweight device 50 retracts (moves toward the rotation axis 13 of the upper rotating body), the first arm 31 pivots outward from the position shown in FIG. 1, while the second arm 32 simultaneously pivots inward. The two first arms 31 pivot in opposite rotational directions, and the two second arms 32 also pivot in opposite rotational directions. On one side of the ballast frame 22, the first arm 31 and the second arm 32 also pivot in opposite rotational directions. This superposition of two counter-rotational pivotal movements about the two longitudinal rotational axes 33, 34 on each side results in an overall linear movement of the ballast cylinder 26, and thus of the entire counterweight device 50. During this movement, the connection between the ballast cylinder 26 and the connecting element 70 remains loaded at all times.

[0068] In the exemplary embodiment shown in Fig. 1, both first arms 31 can be pivoted by means of hydraulic adjustment cylinders 36, respectively. The adjustment cylinders 36 are articulatedly connected to both the upper rotating body 14 and the first arms 31, which can have laterally protruding lugs 37 for this purpose (see Fig. 2), on which the adjustment cylinders 36 are mounted. The two adjustment cylinders 36 are synchronously controlled by the hydraulic system and the control unit so that the first arms 31 pivot synchronously but in opposite rotational directions. To synchronize the adjustment cylinders 36, suitable sensors, such as length sensors, can be provided in or on the adjustment cylinders 36, transmitting signals to the control unit.

[0069] In principle, the second arm 32 can also be pivoted relative to the first arm 31 via its adjusting cylinder, which is articulatedly connected to the first and second arms 31, 32. Here too, it is necessary to ensure a suitable synchronization of the adjusting cylinders of each second arm 32 with one another and with the adjusting cylinder 36 of the first arm 31.

[0070] 1, however, the second arm 32 is mechanically coupled to the first arm 31 such that when the first arm 31 is pivoted, the second arm 32 automatically rotates about the longitudinal axis of rotation 34. In this exemplary embodiment, the mechanical coupling is achieved by a gear or chain transmission. The following discussion relates to one side of the ballast device 20, and thus to one of the two pairs of first and second arms 31, 32.

[0071] The first gear wheel 41 is rotatably fixed on the same line as the first rotation axis 33, i.e., it is joined so as not to move relative to the ballast frame 22. When the first arm 31 rotates, the first gear wheel 41 does not rotate with the first arm 31. The second gear wheel 42 is rotatably fixed to the end of the second arm 32 on the first arm 31 side and is arranged on the same line as the second rotation axis 34. When the second arm 32 rotates relative to the first arm 31, the second gear wheel 42 also rotates relative to the first arm 31. The two gear wheels 41, 42 are connected together via a chain 43 (= connecting means). When the first arm 31 is rotated about the first rotation axis 33 by the adjusting cylinder 36, the first arm 31 also rotates about the rotatably fixed first gear wheel 41. Due to the mechanical connection via chain 43, this pivoting movement of first arm 31 drives second arm 32, which pivots in the opposite direction relative to first arm 31 about a second longitudinal axis of rotation 34.

[0072] The first gear wheel 41 has a larger diameter than the second gear wheel 42, resulting in a defined transmission ratio. As a result, the second arm 32 rotates about the second longitudinal axis of rotation 34 at a greater angular velocity than the first arm 31 about the first longitudinal axis of rotation 33. This is necessary to achieve an overall linear motion of the ballast cylinder 26. The first gear wheel 41 can be designed in this way, or it can be designed as a large gear and the second gear wheel 42 as a pinion.

[0073] The pivoting movement of the second arm 32 results in the rotation of the ballast cylinder 26 relative to the associated connecting element 70. This results in a relative movement between the coupling part 27 and the receptacle 76, which leads to an increase in friction. To avoid this, the piston rod of the ballast cylinder 26 can be fixed to the cylinder housing so that the piston rod can rotate about its longitudinal axis. Therefore, a relative movement between the coupling part 27 and the receptacle 76 must not be assumed. However, in the absence of further fastening elements, the ballast cylinder 26 must press the counterweight device 50 against the ballast device 20 during crane operation. For this purpose, the ballast cylinder 26 is hydraulically disconnected (fixed mode) once a sufficient contact pressure is reached. In order to rotate the piston rod of the ballast cylinder 26 and achieve this friction to adjust the counterweight radius, the ballast cylinder 26 must be released (i.e. the hydraulic shutoff must be released) and the piston rod will extend slightly downwards, and only then can a new counterweight radius be set in the position thus reached (adjustment mode).

[0074] The counter torque generated by the counterweight device 50 can be monitored by a sensor that transmits the data to the load torque limiter of the mobile crane 10. This can be done by detecting the swing angle of at least one of the first and second arms 31, 32 and / or by directly measuring the distance of the counterweight device 50 from the upper rotating bed 14.

[0075] As an alternative to using two synchronized adjusting cylinders 36 for pivoting both first arms 31, it is possible to provide only a single adjusting cylinder 36 and to mechanically couple the two first arms 31 to one another. A corresponding second exemplary embodiment is shown in FIG. 2 in a perspective view of the upper rotating body 14. In this case, the two first arms 31 are mechanically coupled to one another by a gear or chain transmission, and only one of the two first arms 31 can pivot via the adjusting cylinder 36, while the other first arm 31 moves automatically and synchronously.

[0076] 2 shows three exemplary embodiments: adjustment by two adjusting cylinders 36 and adjustment by chain 49. It is also possible to use chain 49 as a means of synchronizing the adjusting cylinders 36.

[0077] The first gear wheel 45 is rotatably connected to one of the first arms 31 (e.g., the arm 31 that can be pivoted by the adjusting cylinder 36) and is arranged collinearly with the first longitudinal axis of rotation 33. In the exemplary embodiment shown here, in which the first and second arms 31, 32 are also connected to each other by a chain transmission, the gear wheel 45 rotatably fixed to the first arm 31 can be arranged above and collinearly with the gear wheel 41 rotatably fixed to the upper rotating body 14 and can be guided through the stationary gear wheel 41 to the first arm 31, for example, via a hollow shaft. During the pivoting movement of the first arm 31, the gear wheel 45 rotates relative to the gear wheel 41 rotatably fixed to the upper rotating body 14.

[0078] The second gear wheel 46 is rotatably fixedly connected to the other first arm 31 and is arranged collinearly with its first rotational longitudinal axis 33 and with the gear wheel 41 rotatably fixedly connected to the upper rotating body 14. The second gear wheel 46 is the counterpart of the first gear wheel 45.

[0079] The third gear wheel 47 is freely rotatably mounted on the upper rotating body 14 next to the second gear wheel 46 and is connected to the first gear wheel by a connecting means in the form of a chain 49. For transmission purposes, a fourth gear wheel 48 is arranged on a common shaft together with the third gear wheel 47 (the third gear wheel 47 is hidden by the fourth gear wheel 48 in FIG. 2 ) and rotates together with the third gear wheel 47. The fourth gear wheel 48 has a larger diameter than the third gear wheel 47 and meshes with the second gear wheel 46, which has a larger diameter than the first gear wheel 45. Now, when the first arm 31 is turned by the adjusting cylinder 36, the first gear wheel 45 also rotates, and due to the connection by the chain 49, the third gear wheel 47 also rotates. The fourth gear wheel 48 is used to rotate the second gear wheel 46, which is connected to the other rotatably fixed first arm 31, in the opposite direction to the first gear wheel 45, so that both first arms 31 pivot in opposite directions at the same angular velocity. Due to the connection of the first and second arms 31, 32 by a further chain drive, the second arm 32 also pivots in a synchronized manner.

[0080] 2, the synchronizing drive for connecting the two first arms 31 is represented on top of the ballast frame 22 for better visualization. However, it is also possible for the synchronizing drive to be located in a different place, for example in the steel structure or on the underside of the ballast frame 22. This also applies to the gears connecting the first and second arms 31, 32.

[0081] The adjusting cylinder 36 can also be located in a different position or drive the first arm 31 in a different way. Another possibility is shown in Figure 3 (which is considered in all exemplary embodiments shown in this specification). Here, the adjusting cylinder 36 is connected in an articulated manner to the ballast frame 22 and to a gear wheel 60 which acts as a connecting wheel. The connecting wheel 60 (in this embodiment via a chain 48 connected to the first gear wheel 45 and to a gear wheel mounted below the connecting wheel 60 on a common shaft and meshing with the second gear wheel 46 with a possibly suitable transmission ratio) drives the first and second gear wheels 45, 46 which are non-rotatably connected to the first arm.

[0082] 2 shows a combination of both exemplary embodiments for synchronizing the first arms 31, where the first arms 31 are mechanically coupled to each other by a chain transmission, while two adjusting cylinders 36 are shown at the same time. However, in practice, only one of these two adjustment mechanisms is usually used (i.e., either two synchronized adjusting cylinders 36, or one adjusting cylinder 36 and a chain transmission).

[0083] 3-8 show an alternative method of converting the pivoting motion of the first arm 31 into linear motion of the counterweight device 50 parallel to the longitudinal axis of the upper pivot body.

[0084] A third exemplary embodiment is shown in perspective view in Figure 3, which shows the counterweight device 50 connected to the ballast device 20. This exemplary embodiment differs from the one in Figures 1 and 2 in that the second arm 32 is not provided and the ballast cylinder 26 is arranged directly at the free end of the first arm 31.

[0085] In order to counteract the circular movement of the ballast cylinder 26, the connection element 70 is here not rigidly connected to the counterweight base plate 52 but is pivotable about a horizontal pivot axis 73. When the first arm 31 is pivoted to the side, during which the lateral distance between the ballast cylinder 26 and the longitudinal axis of the upper structure changes, the tiltably mounted connection element 70 pivots therewith or moves to the side accordingly.

[0086] To ensure a stable connection of the connecting part 27 of the ballast cylinder 26 in the receptacle 76 of the connecting element 70, the connecting element 70 is not formed as one piece, as in the previously described exemplary embodiment, but comprises a base body 72 pivotably connected to the counterweight base plate 52, and at its end facing the first arm 31 a further swiveling body 74 is pivotably mounted about a horizontal swivel axis 75. The swiveling body 74 has a connection part with the receptacle 76 for the ballast cylinder 26.

[0087] On the one hand, the swivel bed 74 counteracts tilting movements of the base body 72, thus ensuring that no relative swivel movements between the receptacle 76 and the connecting part 27 occur. In combination with the aforementioned possibility of rotatably supporting the piston rod of the ballast cylinder 26 in the adjustment mode, it is even possible to prevent any kind of relative movement between the receptacle 76 and the connecting part 27. On the other hand, the swivel bed 74 can be designed so that it automatically aligns itself to a vertical position by gravity. For this purpose, the swivel axis 75 can be arranged in its upper area so that the center of gravity of the swivel bed 74 is located below the swivel axis 75. This allows the connecting part 27 of the ballast cylinder 26 to be connected as usual to the vertically aligned connecting part of the connecting element 70.

[0088] Figures 4-7 show the exemplary embodiment of Figure 3 in four different positions of the counterweight device 50 as it moves from the minimum counterweight radius to the maximum counterweight radius. In Figure 4, the first arm 31 is fully folded forward, and the counterweight base plate 52 is at a minimum distance from the upper rotating body's rotation axis 13. The base body 72 of the connecting element 70 is pivoted inward (i.e., toward the upper rotating body's longitudinal axis).

[0089] By pivoting or folding the two first arms 31 sideways, the counterweight base plate 52 moves away from the rotation axis 13 of the upper rotating body in a direction straight and parallel to the longitudinal axis of the upper rotating body. The pivoting movement of the first arms 31 is offset by the fact that the base body 72 of the connecting element 70 pivots outward laterally (i.e., away from the longitudinal axis of the upper rotating body). Here, the base body 72 also pivots relative to the pivoting body 74 connected to the ballast cylinder 26. At a certain pivoting angle of the first arms 31, the base body 72 is aligned vertically (see FIG. 5).

[0090] Continuing to pivot the first arm 31 further increases the distance between the counterweight base plate 52 and the rotation axis 13 of the upper bed. The base body 72 of the connecting element 70 now pivots outward laterally and tilts away from the longitudinal axis of the upper bed. This position is shown in Figure 6, where the first arm 31 protrudes from the ballast frame 22 perpendicular to the longitudinal axis of the upper bed, resulting in the ballast cylinder 26 being at its maximum distance from the longitudinal axis of the upper bed (which corresponds to the maximum outward pivot angle of the base body 72).

[0091] As the first arm 31 pivots further, the distance between the ballast cylinder 26 and the longitudinal axis of the upper rotating body becomes shorter again, so that the base body 72 pivots inward again, possibly even beyond the vertical position, and again tilts inward at the end position of the counterweight base plate 52 (see FIG. 7).

[0092] It should be noted here that the pivotable base body 72 of the connecting element 70 assumes certain limiting angles outward (see FIG. 6) and inward (see FIG. 4 or 7) relative to the vertical plane, i.e., the base body 72 pivots within a defined angular interval. This angular interval can be smaller than [-20°, 20°], preferably smaller than [-15°, 15°], relative to the vertical position (see FIG. 5). On the one hand, this means that any counterweight plates stacked on the counterweight base plate 52 must be provided with a corresponding free space or a corresponding wide recess through which the base body 72 can protrude without colliding. On the other hand, the pivoting movement of the base body 72 about the horizontal pivot axis 73 results in a height offset 80 of the counterweight base plate 52 (see FIG. 5). Although this height offset 80 is not very large, for example, within a few centimeters (e.g., 20 mm), the mass of the entire counterweight device 50 that can be lifted is very large. The resulting stroke must be applied by the adjusting cylinder 36 and must be taken into account for the boom.

[0093] In a preferred embodiment, the pivotable base body 72 can be pressed into a base position under spring load. It can be pivoted inward, for example, as shown in FIG. 4, or can be in a vertical position, as shown in FIG. 5. The spring can have a corresponding strength, for example, as a disk spring. In the base position, the pivot body 74 with the receptacle 76 is in a connection position, specifically for connection with the connecting part 27 of the ballast cylinder 26.

[0094] In the third embodiment, the ballast cylinder 26 that presses the counterweight device 50 against the ballast frame 22 may also be a necessary object (see above).

[0095] In addition, instead of the two first arms 31 being mechanically coupled by a chain transmission, two synchronously operated adjusting cylinders 36 can also be provided on the two first arms 31 .

[0096] Finally, the fourth exemplary embodiment of FIG. 8 shows an alternative way of accommodating the relative movement between the connecting element 70 and the coupling part 27. Here, only the first arm 31 and the counterweight device 50 are sketched in a schematic manner. As outlined above, the piston rod of the ballast cylinder 26 with the coupling part 27 is also rotatably mounted (at least in one adjustment mode) on the cylinder sleeve. This degree of rotational freedom reduces the frictional connection between the receptacle 76 and the coupling part 27. However, in contrast to the third exemplary embodiment, the connecting element 70 is here formed in one piece, and the pivoting movement of the connecting element 70 and the coupling part 27 is possible via a crown-type connection. For this purpose, both the receptacle 76 and the coupling part 27 preferably have corresponding curved or circular surfaces, which result in a connection in the manner of a ball joint.

[0097] In the solution according to the invention, the undercarriage, in comparison with the prior art, only requires a single storage device for the counterweight device 50. The counterweight radius is adjusted during crane operation, not during counterweight setup. The undercarriage can therefore optimally be designed without this feature. [Explanation of symbols]

[0098] 10 Mobile Crane 13 Rotation axis of upper rotating body 14 Upper rotating body 20 Ballast equipment 22 Ballast frame 24 Winch 26 Ballast cylinder 27 Connecting parts 31 First Arm 32 Second Arm 33 Vertical axis of rotation 34 Vertical axis of rotation 36 Hydraulic adjusting cylinder (or other linear drive) 37 Rug 41 Rotatably fixed gear wheel 42 Rotatably fixed gear wheel 43 Connection means (chain) 45 1st gear wheel 46 2nd gear wheel 47 3rd gear wheel 48 4th gear wheel 49 Connection means (chain) 50 Counterweight device 52 Counterweight base plate 60 Connected Wheels 70 connecting elements 72 Base Body 73 Horizontal pivot axis 74 Rotating body 75 Horizontal pivot axis 76 receptacle 80 Height Offset

Claims

1. a movable lower running body; a rotating upper body (14) attached to the undercarriage for rotation about a rotating axis (13) of the rotating upper body, the rotating upper body (14) having a ballast device (20) and a telescoping boom; 1. A mobile crane (10) comprising: a counterweight device (50) connectable to the ballast unit (20), the counterweight device (50) comprising a counterweight base plate (52) and at least one connection element (70) extending from the counterweight base plate (52) for lifting and connecting the counterweight device (50) to the ballast unit (20), a distance from the counterweight device (50) to the rotation axis (13) of the upper rotating body can be adjusted by at least one first arm (31) of the ballast device (20) that is rotatable about a rotation vertical axis (33) in a ballast state in which the counterweight device (50) is retracted into the upper rotating body (14); In the ballast state, the first arm (31) is connected to the counterweight base plate (52) via a pivotable connecting element; the pivotable connecting element is pivotally attached to the first arm (31) and the counterweight base plate (52) such that the counterweight base plate (52) can be adjusted in a radial linear motion relative to the rotation axis (13) of the upper rotating body by simultaneously pivoting the first arm (31) and the connecting element; A mobile crane (10) characterized by:

2. 2. The mobile crane (10) of claim 1, the counterweight device (50) comprises two spaced apart connecting elements (70) for connecting the counterweight device (50) to the ballast device (20); The ballast device (20) of the mobile crane (10) includes two pivotable first arms (31) that can pivot synchronously to adjust the distance of the counterweight device (50) from the rotation axis (13) of the upper rotating body.

3. 3. The mobile crane (10) of claim 2, The mobile crane (10) is configured such that the first arm (31) is disposed laterally relative to the ballast device (20), specifically, the ballast frame (22), and is rotatable in the opposite direction to adjust the distance of the counterweight device (50) from the rotation axis (13) of the upper rotating body.

4. 3. The mobile crane (10) of claim 2, Each of the first arms (31) is pivotable via its own hydraulic cylinder (36); The mobile crane (10) is characterized in that the hydraulic cylinders (36) are operable synchronously.

5. 3. The mobile crane (10) of claim 2, One of the first arms (31) is pivotable via a hydraulic cylinder (36); The first arms (31) are mechanically coupled to each other by a gear transmission device so as to rotate synchronously when the hydraulic cylinder (36) is operated; The gear transmission device preferably comprises: gear wheels (45, 46) rotatably fixedly connected to the first arm (31) and connected to each other by a connecting means (49), specifically a chain; at least one further gear wheel (47, 48) connected between said gear wheels (47, 48); A mobile crane (10) comprising:

6. 3. The mobile crane (10) of claim 2, the ballast device (20) is designed to lift the counterweight device (50) from a storage area of ​​the undercarriage and place it on the undercarriage; At least one of the connection elements (70) has a connection portion at an end opposite the counterweight base plate (52) that can be connected to the ballast device (20).

7. 7. The mobile crane (10) of claim 6, the ballast device (20) comprising at least one hydraulic ballast cylinder (26) releasably engageable with the coupling portion of at least one connecting element (70); The mobile crane (10), wherein the connecting portion comprises a receptacle (76) in which the connecting part (27) of the ballast cylinder (26) can be stored, specifically by rotating the upper rotating body (14) about the rotation axis (13) of the upper rotating body.

8. A mobile crane (10) according to claim 7, At least one of the receptacle (76) and the connecting piece (27) has a rounded profile that allows articulation of the connecting piece (27) within the receptacle (76) in the presence of a load.

9. A mobile crane (10) according to claim 7, The ballast cylinder (26) Cylinder jacket and a piston removable within the cylinder jacket, the piston having a piston rod at its free end where the connecting piece (27) is located; Equipped with the piston is mounted in the cylinder jacket so as to be rotatable about a longitudinal axis of the piston rod; The ballast cylinder (26) can be operated by a hydraulic system; the ballast cylinder (26) and the hydraulic system are designed such that in the ballast state, in a fixed mode, the piston rod is blocked from extending and rotating, while in an adjustment mode, the piston rod can rotate in the same extended position relative to the cylinder jacket; The mobile crane (10), wherein the piston rod is preferably extended further in the adjusting mode than in the fixed mode.

10. 3. The mobile crane (10) of claim 2, The mobile crane (10) further comprises at least one second counterweight element stackable on the counterweight base plate (52) and having at least one recess through which at least one connecting element (70) protrudes in an arranged state.

11. 2. The mobile crane (10) of claim 1, In particular, a measuring device for detecting the ballast state of the mobile crane (10), which is transmitted to a control unit for load motion limitation, The mobile crane (10), wherein the measuring device preferably comprises at least one sensor capable of detecting the instantaneous swing angle of at least one of the first arms (31).

12. 2. The mobile crane (10) of claim 1, a second arm (32) connected to at least one of the first arms (31) so as to be pivotable about a longitudinal axis of rotation (34); At least one of the connection elements (70) of the counterweight device (50) is connectable to at least one of the second arms (32) by a ballast cylinder (26) arranged on the second arm (32).

13. A mobile crane (10) according to claim 12, the first and second arms (31, 32) are connected to one another in such a way that when the first arm (31) is pivoted about the longitudinal axis of rotation (33), the second arm (32) is automatically pivoted about a longitudinal axis of rotation (34) connecting the first and second arms (31, 32) to one another, specifically in the opposite direction; The mobile crane (10) has a fixed ratio of rotation angles of the first and second arms (31, 32) to each other.

14. A mobile crane (10) according to claim 12, The first and second arms (31, 32) are connected to each other via a second hydraulic cylinder; A mobile crane (10) in which a first hydraulic cylinder (36) that rotates the first arm (31) relative to the upper rotating body (14) and a second hydraulic cylinder that rotates the second arm (32) relative to the first arm (31) are synchronized and controlled so that the angular velocities of the first and second arms (31, 32) are in a fixed ratio to each other during rotation.

15. A mobile crane (10) according to claim 12, the first and second arms (31, 32) are mechanically connected to each other by a gear transmission device so that the first and second arms (31, 32) rotate synchronously when a hydraulic cylinder that rotates the first arm (31) relative to the upper rotating body (14) is operated; The gear transmission device preferably comprises: a first gear wheel (41) connected to the upper rotating body (14) so ​​as to be rotatably fixed; a second gear wheel (42) rotatably fixedly connected to the second arm (32); and The mobile cranes (10) are connected to each other by means of connecting means (43), in particular chains.

16. 3. The mobile crane (10) of claim 2, The connection element (70) of the counterweight device (50) is pivotally connected to the counterweight base plate (52) and, specifically, can be coupled to at least one first arm (31) by a ballast cylinder (26) arranged on the first arm (31).

17. 17. The mobile crane (10) of claim 16, In order to offset the circular movement of the first arm (31) when the first arm (31) is rotated to adjust the distance from the counterweight device (50) to the rotation axis (13) of the upper rotating body, each of the connection elements (70) is connected to the counterweight base plate (52) so as to be pivotable about a horizontal rotation axis (73) such that the connection element (70) rotates laterally, specifically perpendicular to the direction of movement of the counterweight device (50).

18. 18. The mobile crane (10) of claim 17, The connecting element (70) comprises a base body (72) pivotally connected to the counterweight base plate (52); a pivot body (74) is connected at the end facing the first arm (31) to be pivotable about a pivot axis (75), in particular a horizontal pivot axis, in order to compensate for the inclined position of the connecting element (70); The mobile crane (10) wherein the rotating body (74) has a connection portion by which a connection to the first arm (31) of the ballast device can be established.

19. 18. The mobile crane (10) of claim 17, The mobile crane (10) is characterized in that each of said connecting elements (70) is compressively stressed to a vertical or inwardly pivoted position by a return element, in particular a spring.

20. 18. The mobile crane (10) of claim 17, The connecting element (70) is connected to the counterweight base plate (52) so as to be pivotable in both directions at a maximum pivot angle relative to a vertical plane; The mobile crane (10), wherein the maximum slewing angle is preferably less than 20°, particularly preferably less than 15°.

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