Mobile crane equipped with counterweight device, counterweight device and method for assembling same

The counterweight device for mobile cranes, comprising a carrier plate and hanging weights as an assembly unit with dual connections, addresses the inefficiencies and safety risks of traditional counterweight assembly by enabling simultaneous lifting and stable attachment, thus reducing setup time and enhancing safety.

JP7733765B2Active Publication Date: 2025-09-03LIEBHERR WERK EHINGEN
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Patent Information

Application Number
JP2024063794
Authority / Receiving Office
JP · JP
Patent Type
Patents
Current Assignee / Owner
Priority Date
2023-04-17
Filing Date
2024-04-11
Publication Date
2025-09-03
Estimated Expiration
2044-04-11

AI Technical Summary

Technical Problem

Existing mobile cranes require time-consuming disassembly and reassembly of counterweight components for transport, increasing setup time and risking additional work steps and safety hazards due to multiple lifts and connections.

Method used

A counterweight device for mobile cranes that includes a carrier plate and hanging weights, configured as an assembly unit, allowing simultaneous lifting and assembly onto the upper truck, with dual connection elements for stability and safety, reducing the need for separate lifting and installation steps.

Benefits of technology

Significantly reduces setup time and enhances safety by allowing the counterweight device to be transported and assembled in a single lift, ensuring stable connections and preventing detachment during operation.

✦ Generated by Eureka AI based on patent content.

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Patent Text Reader

Abstract

To provide a counterweight device capable of quickly and safely installing on a general-purpose mobile crane.SOLUTION: A carrier plate 40 and a hanging weight 50 are configured as an assembled unit capable of being lifted together. The hanging weight has sling means 48 for lifting an entire assembly unit. The carrier plate has a second connection element to form a second connection part with a second connection element of the hanging weight. The second connection part is designed to prevent the release of a first hanging connection when the assembly unit is lifted above the hanging weight. The present invention relates to the counterweight device for the mobile crane according to the present invention and relates to the method for assembling the counterweight device to an upper carriage of the mobile crane according to the present invention.SELECTED DRAWING: Figure 4
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Description

[Technical Field]

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

[0002] Generally, a mobile crane comprises a lower truck with a wheeled or crawler chassis, an upper truck mounted to the lower truck for rotation about a vertical axis, a boom (e.g., a telescoping boom or lattice tower boom) pivotally mounted to the upper truck, and a counterweight device, also known as upper truck ballast. At any position on the upper truck, the counterweight rotates with the upper truck, applying a countertorque to the load torque via a lever arm.

[0003] While small mobile cranes can often be transported on public roads as so-called taxi cranes, all of the equipment required for use on construction sites cannot be transported on public roads with large mobile cranes. Therefore, all or part of the crane's components, particularly the counterweight assembly, must be disassembled for transport on public roads and reassembled on-site. Similarly, the counterweight assembly of a crawler crane also generally must be disassembled for transport and then attached to the upper truck at the site of use.

[0004] Therefore, it is known in the prior art to provide a carrier plate or counterweight base plate with connecting elements for detachable connection to the upper truck, on which multiple counterweight elements can be stacked. For this purpose, the upper truck is equipped with a ballast device in its rear area, which allows a counterweight assembly, including the counterweight base plate and the counterweight elements stacked thereon with the connecting elements, to be removed from the floor or from a storage area on the lower truck and placed on the upper truck for assembly. For disassembly, the counterweight base plate with the counterweight elements can be returned to the floor or lower truck. For this purpose, the ballast device typically has one or more hydraulic ballast cylinders that extend downward, engage with the connecting elements of the counterweight assembly, and retract the counterweight assembly onto the upper truck. Counterweight assembly devices with ballast cylinders that extend upward are also known.

[0005] Counterweights are often constructed as a filled box. The box contains all the necessary connecting elements and internal bracing to absorb forces. Also known are hanging weights that have a receiving section for hanging and bolting, and can be suspended from the sides of the central counterweight plate. An example of such a hanging weight used in a counterweight device for a mobile crane is known from Patent Document 1. This type of hanging weight can be suspended by one or two lifts on both sides and is equipped with a pair of sling means (heavy lifting means) that can be removed and lifted using a chain or rope. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] German Patent Invention No. 102020123821 Summary of the Invention [Problem to be solved by the invention]

[0007] The advantage of such hanging weights is that they do not increase the swing radius of the upper truck at the construction site, and their additional mass improves the stabilizing torque when a load is lifted onto the boom, reducing the tendency of the boom to tilt in the direction of the load. However, they have the disadvantage of requiring more lifts to bring each hanging weight to its setup position. Here, the setup position is understood to be the position where the mobile crane's ballast system can reach the assembled counterweight system in its final state and attach it to the rear area of ​​the upper truck, i.e., the side opposite the boom. The additional lifting of counterweight elements takes time, increasing the setup time of the counterweight system or the time required to bring the mobile crane into working condition. Furthermore, the additional lifting and installation of hanging weights carries the risk of adding avoidable work steps.

[0008] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a counterweight device that can be quickly and safely set up on a general-purpose mobile crane. [Means for solving the problem]

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

[0010] Thus, a mobile crane is proposed, which includes a mobile lower truck, an upper truck rotatably mounted on the lower truck, and a counterweight device connectable to the upper truck. More specifically, a boom, e.g., a telescopic boom, is articulated to the upper truck in a manner that allows it to move up and down. The counterweight device includes a counterweight base plate, a carrier plate, and at least two hanging weights that can be detachably connected to the carrier plate. The carrier plate can be directly disposed on the counterweight base plate, i.e., directly on the counterweight base plate, or indirectly disposed on the counterweight base plate (i.e., in this case, additional counterweight elements can be stacked on the counterweight base plate, and additional carrier plates can be disposed on top of them). The carrier plate further includes a first connection element for establishing a first hanging connection with the first connection element of the hanging weight.

[0011] According to the present invention, the carrier plate and the hanging weight are configured as an assembly unit (hereinafter also referred to as the first assembly unit or the upper assembly unit) that can be lifted together. Therefore, the carrier plate and the hanging weight do not need to be lifted separately and assembled with a mobile crane, but can be transported in an assembled state (e.g., by a separate transport vehicle) and lifted together in the assembled state onto the counterweight base plate. This eliminates the need for additional lifting for the hanging weight at the construction site and for the hanging weight to be hooked onto the corresponding hanging connection on site, thereby significantly reducing setup time and improving safety during setup.

[0012] The assembly units can be assembled once before use at the construction site and then do not need to be disassembled during transportation or when installing the mobile crane. The assembly units can remain assembled, for example without a lifting counterweight, until the carrier plates are ready for a specific application. For this purpose, it is preferable to also provide corresponding sling means so that the carrier plates can be lifted individually.

[0013] Further precautions are required to ensure that the carrier plate can be lifted together with the suspension weights: with conventional suspension connections such as those known from US Pat. No. 5,649,599, there is a risk that one of the suspension weights may become detached from the carrier plate when the assembly unit is lifted.

[0014] For this reason, according to the present invention, the carrier plate and the hanging weight have not only first connection means for forming the hanging connection, but also second connection means for forming the second connection, especially after the first hanging connection has been formed. Furthermore, the assembled unit can be lifted using the side hanging weight according to the present invention. For this purpose, the hanging weight has corresponding sling means to which the rope or chain of the hoist can be attached. The second connection means, together with the first connection means, are configured to transmit the large forces that arise during lifting due to the weight of the carrier plate.

[0015] This allows the assembly unit to be lifted by the hanging weight, particularly via the boom of the mobile crane itself, and the counterweight device to be assembled or set up and raised above the upper truck by the ballast device.

[0016] The second connection also serves to stabilize the first suspension connection. Therefore, according to the present invention, the second connection is ByThe design prevents or prevents the first suspension connection of each hanging weight from loosening when lifted. This increases safety not only during the movement of the assembly unit, but also during crane operation when the counterweight device is attached to the upper carriage. Problem cases must also be taken into account, such as when a load on the boom is torn off, which typically generates very large forces. This does not pose an unavoidable risk. These forces can accelerate very heavy components, such as suspended hanging weights, upward against gravity, causing them to break free from adjacent or connected components. The safety feature of the second connection prevents the suspension connection from loosening even in such problem cases.

[0017] The counterweight base plate and / or carrier plate and / or hanging weight may be made of grey cast iron or may be constructed as a filled box structure.

[0018] In one possible embodiment, the upper truck includes a ballast device configured to lift a counterweight device from a storage area of ​​the lower truck and place it on the lower truck.

[0019] Preferably, the ballast device has at least one hydraulic ballast cylinder, which can in particular extend downwards towards the set-up counterweight device and can be connected to the counterweight device, after which the counterweight device can be lifted from the storage area on the lower bogie and moved to the upper bogie by inserting the at least one ballast cylinder, where the counterweight device can in particular be connected to the upper bogie, for example by a bolted connection.

[0020] The ballast system preferably comprises a ballast frame that is connected (particularly bolted) to the upper bogie and that is movable by means of ballast cylinders. Alternatively or additionally, the ballast frame may comprise, for example, a winch structure that is detachably attached to the ballast frame. The ballast frame may be detachably connected to the frame structure of the upper bogie via corresponding fastening elements, such as bolts and bolts, so that it can be removed from the upper bogie for transportation.

[0021] In another possible embodiment, the counterweight device includes at least one connecting element extending substantially perpendicular to the counterweight base plate and connected to the counterweight base plate for lifting and connecting the counterweight device to the upper truck. The carrier plate preferably has at least one recess through which the at least one connecting element protrudes. Thus, when the carrier plate is placed on the counterweight base plate (or another counterweight element stacked thereon), it is "threaded" by the at least one connecting element. In particular, the at least one connecting element corresponds to the entire traction and fastening element of the counterweight device, which reduces the number of parts, facilitates operation or assembly, and ensures a stable connection of the various parts. The at least one connecting element can be constructed in one piece. This eliminates the need for complex welding connections with other parts and simplifies the manufacturing process.

[0022] In another possible embodiment, at least one connecting element has a connection part at its end opposite the counterweight base plate, via which connection it can be connected to a ballast device, in particular a ballast cylinder. The ballast cylinder may have a piston rod extending downward from the ballast device and connectable to the connection part of the connecting element. Preferably, two or more ballast cylinders and a corresponding number of connecting elements are provided.

[0023] In another possible embodiment, the coupling part has a receiving part into which the coupling part of the ballast cylinder can be inserted, in particular by rotating the upper bogie about its axis of rotation. The coupling part can be part of the piston rod of the ballast cylinder or a part connected thereto. The recess of the coupling part can be configured in a known manner to allow the ballast cylinder to be pushed sideways (for example in a circular motion) and to appropriately prevent the ballast cylinder from moving vertically out of the recess when in the coupled state.

[0024] In yet another possible embodiment, the counterweight device comprises a further counterweight element that can be stacked on the counterweight base plate and has at least one recess through which the at least one connecting element protrudes in the stacked state. The further counterweight element is arranged between the counterweight base plate and the carrier plate in the set-up state. If there is only one other counterweight element, the carrier plate preferably rests directly on it. If several further counterweight elements are provided, the carrier plate is particularly placed on top or on at least one connecting element.

[0025] Preferably, the counterweight base plate and at least one further counterweight element also form an assembly unit (hereinafter also referred to as the second or lower assembly unit) that can be lifted together, thereby further reducing the number of lifts required for setup. This assembly unit can, for example, be transported separately from the mobile crane and lifted together, for example by the mobile crane's own boom, into a storage area on the mobile crane's lower carriage for setup.

[0026] The various assembly units can be constructed in such a way that their total weight allows them to be transported cost-effectively on public roads, for example, with one or both assembly units weighing approximately 20 tonnes (or less), although other values ​​are possible depending on the country and requirements.

[0027] In yet another possible embodiment, at least one connecting element has a centering means by which the counterweight device can be positioned in an assembly position on the upper car. In particular, the centering means interacts with a countercentering means (mating centering means) on the upper car to ensure automatic positioning of the counterweight device during lifting onto the upper car. Centering the counterweight device in a predetermined assembly position on the upper car facilitates installation.

[0028] Preferably, the upper bogie has corresponding counter-centering means which, when the counterweight device is raised, interact with the centering means of the connecting element to automatically position the counterweight device in an assembly position where it can be connected to the upper bogie, in particular the aforementioned ballast device. Preferably, the centering means is configured as an element extending essentially in the longitudinal direction of the connecting element, e.g., as a protrusion. Accordingly, the counter-centering means forms a recess into which the centering means moves when the counterweight device is raised. However, the opposite (centering means as a recess and counter-centering means as a protrusion protruding downwards from, e.g., the upper bogie) is also conceivable. The centering means preferably has at least one inclined surface or chamfer, i.e., it can have one or more inclined surfaces, e.g., in one or two directions, to facilitate the mutual engagement of the centering means and counter-centering means. It is also possible to provide a conical shape with a chamfer in the circumferential direction of the centering or counter-centering device.

[0029] Alternatively or additionally, at least one connecting element can have fastening means by which the counterweight arrangement can be releasably connected to the upper car in the assembly position (particularly the assembly position obtained by the aforementioned pre-centering). Thus, the counterweight arrangement is not held on the upper car by the ballast cylinder(s), in particular during crane operation, but is provided with a separate connection via the fastening means of the at least one connecting element, in particular via the corresponding fastening means of the upper car. This allows the counterweight arrangement, including the carrier plate and the hanging weight, to be securely and stably attached to the upper car, and the ballast cylinders to be released.

[0030] In another possible embodiment, the second connection portion forms a rotation axis for the hanging weight, so that the hanging weight pivots relative to the carrier plate when the assembly is lifted. Due to the greater weight of the centrally located carrier plate, the laterally located hanging weights spread apart laterally a predetermined distance when lifted. This rotation or spreading movement is preferably limited by the stop of the first connection element. To allow this rotation or spreading movement, the first connection element must be configured accordingly to allow some mobility even in the connected state.

[0031] Because the spreading increases the distance between the hanging weights by a predetermined distance, the assembly unit, when spread, forms a larger receiving area or a larger recess in the counterweight base plate and can therefore be more easily placed thereon. When placed, the hanging weights are located particularly next to the counterweight base plate and pivot towards the counterweight base plate under their own weight.

[0032] The targeted spreading movement of the hanging weight during lifting makes it easier to place the assembly unit consisting of the carrier plate and the hanging weight onto the counterweight base plate (or other counterweight element placed thereon).

[0033] In yet another possible embodiment, the first connection element comprises a suspension bolt arranged on the carrier plate and a hook element arranged on the suspension weight, the hook element being hooked onto the suspension bolt to secure the suspension weight to the carrier plate. The hook element preferably has a recess open on one side, the recess preferably being wider than the suspension bolt accommodated therein to allow the aforementioned spreading movement due to this predetermined movement. A stop of the first connection element that limits the spreading movement is preferably formed by the aforementioned hook element and the suspension bolt. Instead of the aforementioned hook connection, a plug bolt (perforated bolt, anchor bolt) connection may also be used.

[0034] Alternatively or additionally, the recess in the hook element can widen towards the opening to facilitate insertion of the suspension bolt.

[0035] In yet another possible embodiment, the carrier plate has cavities, particularly at the sides or corners, in which the first and second connection elements are arranged so that they do not protrude beyond the outer periphery of the carrier plate in plan view, so that the overall width of the carrier plate does not increase, especially when used without a suspension weight. The cavities can be formed by enclosing them in thin plates of the carrier plate, if they are formed as a sheet metal filler box structure.

[0036] In another possible embodiment, the counterweight device is configured so that, when the carrier plate is in the set-down position, the hanging weight connected to the carrier plate is located adjacent to the side of the counterweight base plate. In particular, the hanging weight can have a height corresponding to the total height of the counterweight package, including the counterweight base plate, other counterweight elements, and the carrier plate. However, it is of course also possible for the hanging weight to be shorter or to protrude above the carrier plate.

[0037] For stable attachment and fastening of the counterweight arrangement to the upper carriage, it is preferred to provide one or more connecting elements. In yet another possible embodiment, the counterweight arrangement therefore consists of at least two or more connecting elements connected to the counterweight base plate and arranged at a distance. There may be exactly two connecting elements or more than two connecting elements. The connecting elements are preferably flat in shape.

[0038] The connecting elements are preferably positioned at the same distance from the center of gravity or from the centerline of the counterweight base plate (which is preferably aligned parallel to the longitudinal axis of the upper truck), which allows for an axisymmetric arrangement of the counterweight base plate and the connecting elements.

[0039] Alternatively, or in addition, the connecting elements can be arranged to rotate relative to each other (each around a vertical axis), i.e., their connections do not point towards each other. This is due to the circular movement of the ballast cylinders caused by rotating the upper truck to establish a connection with the connecting elements. However, it is preferable to arrange the connecting elements parallel to each other, without rotating relative to each other. This simplifies the manufacture of the counterweight base plate and the counterweight elements that are placed on it.

[0040] The counterweight base plate, including the connecting element and / or carrier plate, preferably has an axisymmetrical structure with respect to a central axis passing through the center of the counterweight device.

[0041] The present invention also relates to a counterweight arrangement for a mobile crane according to the present invention, which obviously provides the same advantages and characteristics as the mobile crane according to the present invention, and therefore a repeated description will be omitted. The counterweight arrangement preferably has at least one further counterweight element that can be arranged or stacked on the counterweight base plate. The counterweight element preferably has at least one recess for passing at least one connecting element.

[0042] The present invention also relates to a method for assembling a counterweight arrangement according to the present invention to an upper truck of a mobile crane according to the present invention, said method comprising the steps of: placing the counterweight base plate in a storage area of ​​the lower carriage, in particular by the boom of the mobile crane; Lifting an assembly unit having a carrier plate and a hanging weight connected thereto by a sling means of the hanging weight; placing the assembly unit on a counterweight base plate, in particular directly on the counterweight base plate or on other counterweight elements stacked on the counterweight base plate; Lifting the entire counterweight arrangement onto the upper carriage by means of a ballast system of the mobile crane, in particular by connecting at least one ballast cylinder to at least one connecting element connected to the counterweight base plate and protruding through the carrier plate; It has.

[0043] It is clear that the same advantages and characteristics as those of the mobile crane according to the present invention can be obtained by this, and therefore the description will not be repeated. In particular, the possible embodiments and optional features described with respect to the mobile crane according to the present invention also apply to the method according to the present invention.

[0044] In one possible embodiment of the method, the first and second connection portions are formed as described above, and the second connection element forms an axis of rotation about which the hanging weight pivots relative to the carrier plate when lifted. Thus, when the assembly unit is lifted, the hanging weight spreads laterally as described above, so that when the assembly unit spreads, it forms a wider receiving area for the counterweight base plate on which it can be set down. The hanging weight is preferably located adjacent to the counterweight base plate when placed and pivots toward the counterweight base plate.

[0045] Further features, details and advantages of the invention emerge from the following exemplary embodiments described with the aid of the drawings. [Brief explanation of the drawings]

[0046] [Figure 1] FIG. 1 is a side view of a mobile crane according to an exemplary embodiment of the present invention. [Figure 2] FIG. 2 is a rear view of the counterweight device according to the present invention during setup. [Figure 3] FIG. 3 is a rear view of the counterweight device in the set-up state. [Figure 4] FIG. 4 is a plan view of the counterweight device in the set-up state. [Figure 5] FIG. 5 is an enlarged plan view of a cross section of a connection portion of a hanging weight. [Figure 6] FIG. 6 is a side view of the connection portion of FIG. [Figure 7]FIG. 7 is a rear view of the set-up counterweight device 10 with the attached assembly unit 11 being lifted by a sling rope. DETAILED DESCRIPTION OF THE INVENTION

[0047] Figure 1 is a side view of an exemplary embodiment of a mobile crane 1 according to the present invention in the form of a crawler crane. The mobile crane 1 comprises a lower truck 2 with a crawler chassis and an upper truck 4 mounted to the lower truck 2 so that it can rotate about a vertical axis of rotation 3. The upper truck 4 has a telescoping boom 6 mounted to move up and down about a horizontal axis, and a counterweight arrangement also known as upper truck ballast.

[0048] In this exemplary embodiment, the upper bogie ballast includes a ballast frame 7, which is preferably connected to the steel structure of the upper bogie 4 via bolted connections and can be removed from the upper bogie 4 for transport. The ballast frame 7 is fitted with two hydraulic ballast cylinders 8, each with an extendable piston rod and a connecting piece. The counterweight device 10 can be lifted from the storage area 5 onto the upper bogie 4 by the ballast cylinders 8 and connected to the upper bogie. Conversely, the counterweight device 10 can be returned to the storage area 5 by extending the ballast cylinders 8, from where it can be loaded onto a transport vehicle using the boom 6 of an assist crane or mobile crane 1.

[0049] In this exemplary embodiment, the storage area 5 is formed by a hinged storage device at the rear of the undercarriage 2, which has two pivoting hinge parts in which the counterweight device 10 can be stored. However, the storage area may also be located on the top surface of the undercarriage 2 or on the floor, for example.

[0050] The counterweight device 10 has a counterweight base plate 20, on which one or more counterweight elements 22, preferably in the form of plates, can be stacked. Furthermore, a plurality of hanging weights 50, which will be described later, are provided. This allows the upper truck ballast to be variably configured and adapted to the required application. In the exemplary embodiment shown here, a single additional counterweight plate 22 (separate from the carrier plate 40, which will be described later) is provided. A side view of the rear of the counterweight device 10 is shown in FIG. 3.

[0051] The counterweight device 10 is connected to the ballast cylinders 8 via connecting elements 30 that protrude vertically upward from the counterweight base plate 20 and have connecting portions 32 at their upper ends for reversible connection to connecting parts of the ballast cylinders 8, as well as fastening means 36 for fastening the counterweight device 10 to the ballast frame 7. The alignment or positioning of the counterweight device 10 in the assembled position on the ballast frame 7 is achieved by centering means 34 of the connecting elements 30, and the connection is established by the fastening means 36. The centering means 34 and fastening means 36 can be seen in the side view of Figure 1 (they protrude above the top or carrier plate 40 of the counterweight device 10).

[0052] As shown in Figure 2, which shows the counterweight apparatus 10 set up in a rear view, the counterweight apparatus 10 comprises a carrier plate 40 that forms the top of a ballast stack having a counterweight base plate 20 and additional counterweight elements 22. Attached to the sides of the carrier plate 40 are additional counterweight elements in the form of hanging weights 50, one hanging weight 50 per side in the exemplary embodiment described herein.

[0053] The hanging weight 50 is positioned to extend to the lower counterweight base plate 20 when the counterweight apparatus 10 is fully assembled (i.e., set up). In particular, the height of the hanging weight 50 corresponds to the height of the ballast stack of the counterweight apparatus 10.

[0054] According to the present invention, the carrier plate 40 and the hanging weight 50 form a common (first) assembly unit 11, which can be transported and lifted simultaneously (in this respect it can also be called a transport assembly unit 11). In other words, only one stroke is required to lift the carrier plate 40 and the hanging weight 50 to the storage area 5.

[0055] The counterweight base plate 20 and the further counterweight element 22 arranged thereon also preferably form a common (second) assembly unit 12. For this purpose, the connecting element 30 can have sling (hanging) means (not shown here) (for example in the form of corresponding recesses to which a chain or rope can be attached) to enable the lower or second assembly unit 12 to be lifted via the connecting element 30.

[0056] A possible exemplary embodiment of the storage device 5 of the undercarriage 2 is shown in Figure 1. The central ballast can be assembled directly to the undercarriage 2 via fastening elements and is extended by a hinged holder for the counterweight device 10. Two pivot parts are hingedly connected to the side cheeks of the central ballast and provide a support surface on which the counterweight device 10 can rest.

[0057] To set up the counterweight device 10, the lower assembly unit 12, with the counterweight base plate 20 and the counterweight element 22 already placed thereon, is first lifted from the transport vehicle (e.g., a low-bed truck) and placed in the storage area 5. This lifting is preferably performed by the boom 6 of the mobile crane 1 in self-setup mode, but can of course also be performed by an assist crane.

[0058] The upper assembly unit 11, comprising the carrier plate 40 and the hanging weight 50, is already assembled and transported separately before being lowered (preferably using the boom 6) onto the lower assembly unit 12 (set down). The state immediately before lowering is shown in Figure 2. The space between the hanging weights 50 and below the carrier plate 40 forms the receiving area 13 for the counterweight base plate 20 and the counterweight element 22, and it can be seen that in the set-up state (see Figure 3), the components of the counterweight element 22 are received.

[0059] As shown in Figure 3, the connecting element 30 connected to the counterweight base plate 20 has a length such that it protrudes beyond the top of the carrier plate 40 in the set-up state. For this purpose, both the further counterweight element 22 and the carrier plate 40 have a correspondingly shaped recess through which the connecting element 30 protrudes. The connecting element 30, which can also be called a connecting lever, is in particular a one-piece sheet metal structure, has a flat basic shape and is connected to the counterweight base plate 20.

[0060] The directions "up" and "down" as used herein refer to the counterweight base plate 20 (and mobile crane 1) standing on a horizontal surface with the linking element 30 oriented vertically.

[0061] 4 is a plan view of the carrier plate 40 with the hanging weights 50 attached. It can be seen that the essentially slot-shaped recesses 44 in which the connecting elements 30 are arranged run parallel to one another.

[0062] The connecting element 30 serves both to remove and lift the counterweight arrangement 10 and to center and attach it to the ballast arrangement (or ballast frame 7). For this purpose, the connecting element 30 has a connecting part 32 at the end opposite the counterweight base plate 20 (see Figure 2).

[0063] The connecting parts 32 in particular have upwardly open clamp-shaped recesses 33 (see FIG. 4) into which the specially shaped (in particular mushroom-shaped) ends or connecting parts of the corresponding ballast cylinders 8 can be placed laterally. In the final position where the counterweight arrangement 10 can be safely lifted, the connecting parts of the ballast cylinders 8 are preferably shaped so that they are located in the center of the respective recesses 33, so that the counterweight arrangement 10 can be lifted in an adapted manner by retracting the ballast cylinders 8.

[0064] In the exemplary embodiment shown here, the ballast cylinders 8 are connected to the connecting element 30 by rotating the upper bogie 4 about its axis of rotation 3. For this purpose, the recess 44 is widened to one side (left side in FIG. 4 ) in its central region so that the connecting part of the ballast cylinder 8 next to the connecting element 30 can be moved downwards into the enlarged part 45 of the recess 44 until it reaches the height of the recess 33. The connection can then be established by rotating the upper bogie 4. In the exemplary embodiment shown here, the enlarged parts 45 are rectangular in shape and are slightly offset from one another (i.e. not at the same height in a plan view) in order to take into account the circular trajectory of the ballast cylinders 8 as the upper bogie 4 rotates. Other shapes and arrangements of the recesses 45 are also conceivable.

[0065] After the counterweight arrangement 10 has been raised onto the upper carriage 4 or onto the ballast frame 7, the connecting element 30 is bolted to the ballast frame 7, thereby releasing the ballast cylinder 8 during crane operation. The connecting element 30 thus has fastening means 36 in the region of the coupling 32 (see Figures 1 and 3), which allow a stable connection of the counterweight arrangement 10 to the ballast frame 7. The fastening means 36 are in particular configured as bolt receptacles into which corresponding fastening bolts can be inserted in the assembly position.

[0066] The connecting element 30 also preferably has centering means 34 in the region of the fastening means 36 (see Figures 1 and 3), which in this exemplary embodiment are shown in the form of upwardly projecting protrusions or mandrels tapering in the longitudinal direction of the connecting element 30, which bring the counterweight device 10 into the desired mounting position when the ballast cylinder 8 is retracted. The centering means 34 interact with countercentering means (not shown) of the ballast frame 7, ensuring automatic alignment of the counterweight device 10 when it moves towards the ballast frame 7.

[0067] The hanging weight 50 is removably attached to the carrier plate 40 via two connections 100, 200. The first hanging connection 100 is made by the first connection elements 41, 51 and allows for easy hanging of the hanging weight 50 on the carrier plate 40. For this purpose, the hanging weight 50 has a lateral connection plate 54 in the area of ​​its end face facing the carrier plate 40, which lateral connection plate 54 forms a hook element 51 in its front part. The arrangement of the connection plates 54 is shown in a plan view in Figure 4, while Figures 5 and 6 show a plan view and a side view of these connection plates 54 in the connected state.

[0068] The hook element 51 (= first connection element of the hanging weight 50) has a recess 55 that is open downwards, into which the hanging bolt 41 (= first connection element of the carrier plate 40) is inserted, the hanging bolt 41 being located in a cavity 46 formed in a corner of the carrier plate 40 (see FIG. 4). The hanging weight 50 is hooked onto the hanging bolt 41 of the carrier plate 40 by the hook element 51, thereby forming a first hanging connection 100. In principle, it is also conceivable to provide the carrier plate 40 with a hook element that is open upwards and to provide the hanging bolt on the hanging weight 50.

[0069] Furthermore, the carrier plate 40 and the hanging weight 50 have second connection elements 42, 52, 53 for forming a second connection 200, which protects the first hanging connection 100 and prevents the hanging weight 50 from unintentionally detaching. In the exemplary embodiment shown here, the second connection elements 42, 52, 53 comprise a bolt receptacle 42 formed in the carrier plate 40 in the region of the cavity 46 and a bolt receptacle 52 also formed in the connecting plate 54, into which the corresponding bolt 53 is inserted as soon as the bolt receptacles 42, 52 overlap.

[0070] The cavity 46 is provided in the carrier plate 40 so that the connecting plate 54 does not protrude laterally beyond the outer contour of the carrier plate 40, i.e., so that the connecting plate 54 is located "inside" the cavity 46 in a plan view.

[0071] The second connection 200 or bolted connection not only increases safety when lifting the assembly unit 11 or during crane operations, for example in case of a sudden drop of the load, but also provides a secure connection between the assembly unit 11 and the assembly unit according to the invention, as shown in the side view of FIG. tt 11 above the hanging weight 50. For this purpose, the hanging weight 50 has corresponding sling means 58 spaced from the carrier plate 40 on its side, to which a hanging rope 60 or a hanging chain of a hoist can be attached.

[0072] Without the second connection 200, the suspension connection 100 would easily come loose when the suspension weight 50 is lifted. The first and second connection elements 41, 42, 51, 52, 53 are configured to safely absorb and transmit the forces occurring during lifting.

[0073] 6, the opening 55 in the hook element 51 is wider than the receiving hanger bolt 41. This defined clearance facilitates the attachment of the hanger weight 50. The pivoting action is achieved by the larger bore 52.

[0074] This intentional pivoting movement of the hanging weights 50 facilitates the placement of the upper assembly unit 11 on the lower assembly unit 12 (see FIG. 2). During the lifting of the assembly unit 11, the hanging weights 50 move apart or spread apart by a defined distance due to the aforementioned mobility, thereby widening the receiving area 13 between the hanging weights 50 and facilitating the insertion of the lower assembly unit 12 into this receiving area 13.

[0075] Since the carrier plate 40 can also be used in certain applications without the hanging weights 50, its sides are also provided with corresponding sling means 48. In principle, the assembly unit 11 can also be lifted onto these sling means 48 of the carrier plate 40. However, in this case the effect of unfolding the hanging weights 50, as previously mentioned, does not occur.

[0076] The ballast elements 20, 22, 40, 50 can be constructed as filled box structures or as molded ballast. However, it is preferred that the ballast elements 20, 22, 40, 50 are made of inexpensive and environmentally friendly box structures, for example, in which metal parts are inserted during manufacture and the gaps are filled with a filling compound. However, due to their low specific gravity, in many applications a large amount of additional counterweight is required to generate the torque required for stability. This additional weight is provided by the hanging weights 50.

[0077] Finally, it should be mentioned that a worker may be required to place the counterweight package formed by the assembly unit 11 on top of the counterweight package of the already prepared assembly unit 12 and connect them. This can be done from a comfortable and safe position on the lower carriage 2. The worker simply needs to enter the exposed counterweight device 10 itself and remove or hang down the sling rope 60. However, this does not usually require much effort. If climbing onto the counterweight device 10 is to be completely avoided, a folding ladder can be used, for example. [Explanation of symbols]

[0078] 1. Mobile crane 2 Lower bogie 3 Rotation Axis 4 Upper bogie 5 Storage area 6. Boom 7 Ballast Frame 8 ballast cylinders 10 Counterweight device 11 (Upper) Assembly Unit 12 Second (lower) assembly unit 13 Reception Area 20 Counterweight base plate 22 Counterweight element 30 Connected Components 32 Connecting part 33 Recess (receiving part) 34 Centering means 36 Fastening means 40 Carrier Plate 41 First connecting element (hanging bolt) 42 Second connecting element (bolt receiving portion) 44 Recess 45 Enlarged portion of recess 46 Cavity 48 Sling means 50 Hanging Weights 51 First connecting element (hook element) 52 Second connection element (bolt receiving portion) 53 volts 54 Connecting plate 55 recess 56 Sling means 58 Sling means 60 Sling section 100 First connection part (hanging connection part) 200 Second connection part

Claims

1. 1. A mobile crane (1) comprising: a mobile lower carriage (2); an upper carriage (4) rotatably mounted on the lower carriage (2); and a counterweight device (10) connectable to the upper carriage (4) and having a counterweight base plate (20), a carrier plate (40), and at least two hanging weights (50) releasably connectable to the carrier plate (40), wherein the carrier plate (40) is mountable on the counterweight base plate (20) and has a first connection element (41) for forming a first hanging connection (100) with a first connection element (51) of the hanging weights (50), The carrier plate (40) and the hanging weight (50) are configured as an assembly unit (11) that can be lifted together, the hanging weight (50) has a sling means (58) for lifting the entire assembly unit (11), the carrier plate (40) has a second connection element (42) for forming a second connection (200) with the second connection element (52) of the hanging weight (50), and the carrier plate is configured to prevent release of the first hanging connection (100) when the assembly unit (11) is lifted by the hanging weight (50).

2. A mobile crane (1) according to claim 1, The upper carriage (4) has a ballast device configured to lift the counterweight device (10) from a storage area (5) of the lower carriage (2) and place it thereon, the ballast device comprising at least one hydraulic ballast cylinder (8).

3. A mobile crane (1) according to claim 1, The counterweight device (10) comprises at least one connecting element (30) extending substantially perpendicular to the counterweight base plate (20) and connected to the counterweight base plate for lifting and connecting the counterweight device (10) to an upper carriage (4), and the carrier plate (40) has at least one recess (44) through which the at least one connecting element (30) is placed and protruding.

4. A mobile crane (1) according to claim 2, At least one connecting element (30) has a connecting portion (32) at an end opposite the counterweight base plate (20), and a mobile crane (1) can be connected to a ballast device via this connecting portion.

5. A mobile crane (1) according to claim 4, The mobile crane (1) has a receiving portion (33) into which the connecting part (32) of the ballast cylinder (8) can be inserted by rotating the upper carriage (4) about its rotation axis (3).

6. A mobile crane (1) according to claim 3, The mobile crane (1) further comprises at least one further counterweight element (22) that can be stacked on the counterweight base plate (20) and has at least one recess through which at least one connecting element (30) is inserted so as to protrude in a stacked state, the further counterweight element (22) being arranged between the counterweight base plate (20) and the carrier plate (40) in a ballast state, the counterweight base plate (20) and the at least one further counterweight element (22) also forming a second assembly unit (12) that can be lifted together.

7. A mobile crane (1) according to claim 3, The at least one connecting element (30) of the mobile crane (1) has centering means that can automatically position the counterweight device (10) in an assembly position when the counterweight device (10) is lifted onto the upper cart (4), and / or fastening means (36) that can releasably connect the counterweight device (10) to the upper cart (4) in the assembly position and that have bolt receptacles for bolting to the upper cart (4).

8. A mobile crane (1) according to claim 1, The second connection part (200) forms a rotation axis of the hanging weight (50), and when the assembly unit (11) is lifted, the hanging weight (50) rotates about the rotation axis relative to the carrier plate (40) and moves laterally away by a predetermined distance, and the rotational movement is limited by the stopping of the first connection elements (41, 51).

9. A mobile crane (1) according to claim 1, The first connection element (41, 51) has a hanging bolt (41) arranged on the carrier plate (40) and a hook element (51) arranged on the hanging weight (50), and the hook element (51) has a recess (55) that is open on one side.

10. A mobile crane (1) according to claim 1, The carrier plate (40) has a cavity (46), and the first and second connection elements (41, 42) are arranged in the cavity so as not to protrude beyond the outer periphery of the carrier plate (40) in a plan view.

11. A mobile crane (1) according to claim 1, The counterweight device (10) is configured so that, when the carrier plate (40) is in a set-down state, a hanging weight (50) connected to the carrier plate is positioned adjacent to the side of the counterweight base plate (20).

12. A mobile crane (1) according to claim 1, A mobile crane (1) having a flat shape, in which two spaced apart connecting elements (30) are connected to a counterweight base plate (20).

13. 2. The counterweight device (10) for a mobile crane (1) according to claim 1, further comprising at least one counterweight element (22) that can be stacked on the counterweight base plate (20).

14. A method for assembling a counterweight device (10) on an upper carriage (4) of a mobile crane (1) according to claim 1, comprising the steps of: placing the counterweight base plate (20) in the storage area (5) of the lower carriage (2) by the boom (6) of the mobile crane (1); Lifting the assembly unit (11) having the carrier plate (40) and the hanging weight (50) connected thereto by the sling means (58) of the hanging weight (50); placing the assembly unit (11) on the counterweight base plate (20); Lifting the entire counterweight device (10) onto the upper carriage (4) by a ballast device of the mobile crane (1) by connecting at least one ballast cylinder (8) to at least one connecting element (30) connected to the counterweight base plate (20) and protruding through the carrier plate (40); A method having the following.

15. 15. The method of claim 14, The mobile crane (1) is configured at least as described in claim 8, wherein the hanging weight (50) expands laterally when the assembly unit (11) is lifted, and when expanded, the assembly unit (11) forms an enlarged receiving area (13) for the counterweight base plate (20) on which it can be installed, and the hanging weight (50) is positioned adjacent to the counterweight base plate (20) during lowering and pivots towards the counterweight base plate (20).

Citation Information

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