Crane with counter boom and method for erecting the counter boom

Abstract

Crane, in particular mobile crane or crawler crane, with a main boom (13) and counter boom (3) and an erection stand (40) arranged on the superstructure (12) of the crane, which is connected to a bracing of the counter boom via a cable adjustment (5), characterized in that at least one compression support (311) articulated to the counter boom (3) or on the pivot axis of the counter boom (3) is provided to temporarily receive the cable adjustment (5) and / or the bracing, wherein the receiving point (311a) of the compression support (311) is designed such that the cable adjustment (5) or bracing can, in particular, lift off the compression support (311) independently at a certain erection angle of the counter boom (3).

Description

[0001] The invention relates to a crane, in particular a mobile or crawler crane, with a main boom and counter boom as well as an erection stand arranged on the superstructure of the crane, which is connected to a guying of the counter boom via a rope adjustment.

[0002] A lattice boom crane generally consists of a main boom and a counter boom. The boom system is mounted on a superstructure, which is rotatably mounted on a mobile undercarriage. To assemble the crane, the main boom is erected using the already assembled and erected counter boom, which serves as a support for the cable tensioning system used to raise the main boom.

[0003] For the assembly of the counter boom, an adjustable erection stand mounted on the superstructure is required for the previously known crane types. This is evident in the schematic crane diagrams of the Fig. 1a, Fig. Figure 1b shows a crane with a chassis 11 and a superstructure 12. The adjustable erection stand 4' is connected to the boom head of the counter boom 3 via a guy wire 6. The cable adjustment 5 is attached directly to the superstructure 12 and connected to the guy wire 6. By retracting the cable adjustment 5, the counter boom 3 can be erected. The rationale behind this design is the possibility of operating the crane without the counter boom 3. The adjustable erection stand 4' is a prerequisite for this. This design is particularly suitable for cranes with lifting capacities up to 1500t.

[0004] For large cranes with lifting capacities exceeding 1500t, the use of a counterweight boom is mandatory. Various designs of the required erection support 4 have been developed for such cranes to erect the counterweight boom. The most common design is a stationary erection support 4 mounted on the superstructure 11, which serves as a fixed point and pressure support for the rope adjustment 5 during the erection of the counterweight boom 3. This principle is illustrated in the Fig. 2a, Fig. 2b. A solution with an adjustable erecting stand 4' according to the Fig. 1a, Fig. Option 1b is ruled out here due to the high weight of such a 4' erection stand that would then be required and space problems on the upper carriage.

[0005] A railway crane is known from US document 2,813,636 A. It describes in particular how the boom is erected.

[0006] This application seeks possible improvements to existing solutions.

[0007] This problem is solved by a crane, in particular a mobile crane or crawler crane, with the features of claim 1. Advantageous embodiments of the crane are the subject of the dependent claims. A new and improved process for erecting the counter boom is provided by the features of claim 7. Advantageous embodiments of this method are the subject of the dependent process claims.

[0008] According to the invention, it is proposed to supplement a crane structure with cable adjustment and an erection stand arranged on the superstructure by an additional compression support, which is articulated to the counter boom, particularly in the area of ​​the counter boom foot or the counter boom's pivot axis. Preferably, the compression support is pivotally articulated, in particular pivotable about a horizontal axis. It is also conceivable to articulate the compression support directly to the counter boom's pivot axis. In this case, the pivot axis of the compression support can be coaxial with the counter boom's pivot axis. The cable adjustment is typically connected to the guying system so that the counter boom's erection angle can be changed by actuating the cable adjustment. The guying system typically runs from the cable adjustment to the tip of the counter boom.

[0009] At least during the erection process, the pressure support makes contact with the rope adjustment and / or the guying; in particular, the pressure support receives the rope adjustment and / or guying via a suitable bearing point at its free end. This allows the rope adjustment and / or guying to be pushed away from the back of the counter boom by means of the pressure support.

[0010] The additional compressive force applied by the pressure support to the cable adjustment / bracing allows the erection support used at the rear of the superstructure or turntable to be significantly smaller. The geometry for the lever arm and the generation of the required erection moment are largely determined by the pressure support. In contrast, according to the prior art solution, the erection support must extend relatively far vertically from the superstructure in order to generate a sufficient erection moment for the counter boom.

[0011] A further advantage of the invention is that, with the geometry according to the invention, consisting of an erection stand, rope adjustment, pressure support and bracing, changes in the angle of the counter boom lead to smaller changes in the lever arm, which has a positive effect on the overall process, especially in flat positions.

[0012] The potential size savings in the erection stand also lead to further advantages. The modified geometry of the power transmission results in a shorter required retraction length for the cable adjustment to erect the counter boom.

[0013] According to a preferred embodiment, the pressure support is hinged to the rear of the counter boom. A pivotable hinge for the pressure support on the rear of the counter boom in the area of ​​its boom base proves advantageous. This position of the pressure support results in an optimal influence on the resulting lever arm during the erection of the counter boom.

[0014] According to the invention, the connection between the pressure support and the cable adjustment or bracing is only temporary; that is, the cable adjustment or bracing can detach itself from the pressure support. In particular, it is provided that the cable adjustment / bracing is only operatively connected to the pressure support at the beginning of the bracing process. Once the bracing reaches a specific raising angle, the cable adjustment / bracing detaches itself from the pressure support. To prevent the pressure support from tipping over after the cable adjustment detaches, a corresponding locking mechanism can be provided. The tipping can occur in either direction.

[0015] It is advantageous if the cable adjustment or tensioning mechanism rests on a suitable bearing point of the compression strut, which allows lifting at a specific angle of the counter boom, but also enables the application of a tensile force to the compression strut via the cable adjustment, generating a pivoting movement. This can be achieved through appropriate locking devices, such as the tensioning mechanism, or stops in the area of ​​the bearing point.

[0016] The bearing point of the pressure support is ideally suited for receiving and supporting the roller axle of an upper block of the rope adjustment mechanism. Ideally, this ensures that the movement of the rope pulleys is not impaired, allowing the rope adjustment to function without restriction. For example, the bearing point could allow the roller axle to lift along the longitudinal axis of the pressure support, while preventing relative movements of the upper block perpendicular to the longitudinal axis of the pressure support by means of appropriate lateral stops. It is also conceivable that the upper block of the rope adjustment mechanism could be temporarily fixed to the pressure support by means of a locking mechanism.

[0017] The erection stand used can be designed as a fixed, and in particular triangular, erection stand attached to the superstructure. Preferably, it is mounted at the rear end of the superstructure. In addition to the cable adjustment mechanism, the erection stand can also accommodate a cable adjustment retraction mechanism.

[0018] In an advantageous embodiment of the crane, it is designed as a mobile crane or crawler crane. A suitable lattice boom is used as the counter boom. The main boom is, for example, a lattice boom.

[0019] In addition to the crane according to the invention, the present invention also relates to a method for erecting the counter boom of a crane according to the present invention. According to the invention, the method proposes that, at the beginning of the erection process of the counter boom, when the erection angle of the counter boom is small, the rope adjustment or tensioning is received by the bearing point of the compression support in order to be pushed away from the back of the counter boom by means of the compression support. At a defined erection angle of the counter boom, the rope adjustment / tensioning should lift off the compression support independently.

[0020] The far-reaching advantages resulting from this method have already been explained above using the crane as an example. To avoid repetition, further explanations are omitted here.

[0021] For the execution of the procedure, it is initially proposed to mount the counter boom, along with the already attached compression strut, to the superstructure in a first step. In the subsequent step, the compression strut can be folded forward towards the tip of the counter boom. In the next step, the cable adjustment mechanism is also pulled forward to rest its end against the designated bearing point on the compression strut. Simultaneously, the counter boom's bracing is connected to the cable adjustment mechanism, in particular by bolting.

[0022] In a subsequent step, the compression strut can be raised to a specific angle by retracting the cable adjustment mechanism. This is achieved by appropriate stops or locking devices in the bearing area, which allow the tensile force to be transferred from the cable adjustment mechanism to the compression strut. This tensile force simultaneously tensions the counterweight boom bracing.

[0023] In the next step, the counter jib can be raised by further retracting the rope adjustment mechanism, up to a specific desired raising angle. Once a certain counter jib angle is reached, the rope adjustment automatically lifts off the support leg. The support leg is no longer needed for subsequent crane operations. The counter jib is braced and luffing solely by the guy wires and the rope adjustment. Lowering the counter jib is performed in reverse order. Due to the aforementioned locking mechanism, the support leg remains in a position where it can re-engage the upper block at a specific lowering angle.

[0024] Further advantages and features of the invention will be explained in more detail below with reference to an exemplary embodiment shown in the figures. The figures show: Fig. 1a, Fig. 1b, Fig. 2a, Fig. 2b: different designs of a crane according to the state of the art, Fig. 3a - 3f: Illustrations of the crane according to the invention during the execution of the method according to the invention in chronological order, Fig. 4: A side view of the crane according to the invention with the derrick boom erected and the main boom mounted and Fig. 5a - 5h: various comparisons of a known crane with the crane according to the invention to illustrate the advantages of the invention.

[0025] The crane designs conform to the state of the art, as shown in the Fig. 1a, Fig. 1b, Fig. 2a, Fig. Section 2b was already explained in the introductory section. Therefore, a repeat description is omitted.

[0026] The construction according to the invention is described in the Fig. Figures 3 and 4 are shown. The individual crane components are best viewed in the enlarged view of the Fig. 4. The large crane shown there has a chassis 11, here a crawler track, and a rotating platform 12 mounted on the chassis. A counter boom 3 in derrick design is luffingly articulated to the rotating platform 12. The main boom 13 is also luffingly mounted to the rotating platform and is designed as a lattice mast.

[0027] At the rear end of the superstructure 2 is an erection stand 40, which is rigidly mounted to the superstructure 12. The erection stand 40 is essentially triangular. The cable adjustment mechanism 5 is mounted at the uppermost point of the erection stand 40. The length of the cable adjustment mechanism 5 can be adjusted by means of the retraction mechanism 5a, which is also mounted on the erection stand 40.

[0028] The guying 6, consisting of individual guy rods, is bolted directly to the upper block 51 of the rope adjustment 5. By actuating the retraction mechanism 5a, i.e., retracting the rope, the length of the rope adjustment 5 is reduced, thereby tensioning the guying, changing its length, and allowing the derrick boom 3 to be luffed.

[0029] The pressure support 311 according to the invention is pivotably mounted on the pivoting foot of the derrick boom 3 about a horizontal axis. Its free end is provided with a suitable bearing point 311a to receive the upper block 51 and to exert a pressure force on the pressure support 311.

[0030] The assembly and disassembly process of the derrick boom 6 can be seen from the crane states shown in chronological order. Fig. Illustrate sections 3a-3f. The first step is as follows: Fig. 3a The counter-jib pivot piece 31 of the derrick boom 3 is mounted on the turntable 12. The pressure support 311 is already pre-mounted on the counter-jib pivot piece 31. The disassembly or removal process takes place in reverse order ( Fig. 3f to 3a) instead.

[0031] In the following procedural step according to Fig. 3b, the pressure support 311 is folded forward towards the derrick boom tip. Simultaneously, the rope adjustment 5 is extended by unwinding the retraction mechanism 5a, and the upper block 51 is also pulled forward towards the derrick boom tip so that its pulley axle can be received by the bearing point 311a of the pressure support. At the same time, the upper block 51 is bolted to the guy wire 6 of the derrick boom 3.

[0032] In the next procedural step according to Fig. 3c The pressure support 311 is erected by actuating the retraction mechanism of the rope adjustment 5, in particular pivoted rearward in the direction of the erection stand 40. As a result, the bracing 6 of the derrick boom 3 is simultaneously tensioned.

[0033] By further tightening the rope of the rope adjustment 5 by means of the retraction mechanism 5a, the counter boom 3 can be erected, which the Fig. This can be seen in 3D. Furthermore, the Fig. 3d approximately the erection angle of the derrick boom 3, at which the upper block 51 of the rope adjustment 5 is just barely in the bearing point 311a on the pressure support 311, but is already beginning to lift off from it. By further erecting the derrick boom 3 into the position shown Fig. The position shown in Figure 3e completely lifts the cable adjustment 5 away from the pressure support 311. From this state onward, the pressure support 311 is inoperative and remains in position by means of a locking mechanism. For the sake of completeness, the Fig. 3f still the desired final position of the derrick boom 3. This representation is essentially identical to the representation of the Fig. 4, except that the latter already shows the mounted main boom 13. A known spring press 312 for the counter boom 3 is still necessary and is shown in the Fig. 3a to 3f and 4 are shown.

[0034] Consequently, neither the rope adjustment 5 nor the guy wire 6 contacts the pressure support 311 during regular crane operation. The pressure support therefore remains inactive throughout the entire crane operation and is only required for erecting the derrick boom 3.

[0035] In the Fig. In sections 5a to 5h, schematic representations of the crane according to the invention are compared with prior art crane designs in order to visualize the advantages of the invention. The comparison of the Fig. 5a, Fig. Figure 5b serves to illustrate the size ratios of a lifting stand 4 according to the state of the art ( Fig. 5a) and the erection stand 40 according to the present invention ( Fig. 5b). The clear height difference between the two erection supports 4 and 40 is readily apparent. Erection support 40 is a simpler and smaller fixed erection support 40. This results in a significant weight and cost saving during manufacturing. In order to obtain a sufficient lever arm H when erecting the counter boom 3, it is state of the art ( Fig. 5a) It is necessary to make the erection stand 4 relatively large and high. By using the pressure support 311 described here ( Fig. 5b) the erection stand 40 at the rear of the turntable can be made significantly smaller.

[0036] At the same time, according to the crane according to the invention, a significantly shorter length L for the rope length is required at the winding mechanism of the rope adjustment 5. In direct comparison to a stationary erection stand 4 of conventional design ( Fig. 5d) and the crane structure according to the invention described herein (in accordance with Fig. 5c) shows that the rope length L required for erection using the winch 5a is shorter than in Fig. 5d. The shorter length L is multiplied by the reeving of the rope for rope adjustment 5. The shorter length L is the one used in the solution implemented here ( Fig. 5c) due to the smaller erection stand 40, which leads to a more favorable erection geometry.

[0037] Furthermore, the solution according to the invention also results in a better lever arm H' for the rope adjustment 5 (see Fig. 5e), when the counter boom 3 is erected (a change in the angle of the counter boom 3 results in a smaller change in the lever arm). When the counter boom 3 is erected according to the conventional crane Fig. If the 5f is lowered further downwards, a change in angle of, for example, one degree leads to a greater shortening of the lever arm than in the crane according to the invention as shown in the illustration. Fig. 5e is the case. The relevant lever arm H' here is the vertical distance between the center line of the cable adjustment 5 and the counter-jib pivot point.

[0038] Furthermore, a slightly improved geometry can also be achieved in the crane according to the invention ( Fig. 5g) compared to a conventional crane ( Fig. 5h). Due to the shorter fixed erection stand 40, a better lever arm H'' results in some counter-jib positions, as shown in Fig. 5g compared to Fig. 5h is recognizable. In the representation according to Fig. 5g is the lever arm H'' compared to the lever arm H'' in the same boom length and superstructure length. Fig. 5h slightly longer, meaning that with the same force in the guy wire 6, a larger moment can be generated. The relevant lever arm H'' here is the vertical distance between the boom guy wire 6 and the counter boom pivot point.

Claims

[1] Crane, in particular mobile crane or crawler crane, with a main boom (13) and counter boom (3) and an erection stand (40) arranged on the superstructure (12) of the crane, which is connected to a guying of the counter boom via a rope adjustment (5), characterized by , that at least one pressure support (311) is provided, articulated to the counter boom (3) or to the pivot axis of the counter boom (3), in order to temporarily receive the rope adjustment (5) and / or the bracing, wherein the receiving point (311a) of the pressure support (311) is designed such that the rope adjustment (5) or bracing can, in particular, lift off the pressure support (311) independently at a certain upright angle of the counter boom (3). [2] Crane according to claim 1, characterized by , that the pressure support (311) is pivotably mounted on the rear of the counter boom (3) in the area of ​​its boom foot or pivot axis, in particular pivotable about a horizontal axis. [3] Crane according to one of the preceding claims, characterized by , that the bearing point (311a) of the pressure support (311) for receiving the rope adjustment (5) has a locking mechanism or a stop for the received rope adjustment / tensioning (5) in order to be able to apply a tensile force to the pressure support (311) by means of the rope adjustment (5) which causes a pivoting movement of the pressure support (311). [4] Crane according to one of the preceding claims, characterized by , that the roller axle of an upper block (51) of the rope adjustment (5) can be received by means of the bearing point of the pressure support (311), wherein optionally a locking mechanism for temporarily fixing the roller axle at the bearing point (311a) may be provided. [5] Crane according to any of the preceding claims, characterized by, that the erection stand (40) is designed as an erection stand (40) fixed to the superstructure (12), in particular triangular in shape, and is preferably mounted at the rear end of the superstructure (12), wherein the erection stand (40) preferably accommodates the winch of the rope adjustment (5). [6] Crane according to any of the preceding claims, characterized by , that the counter-jib (3) is a lattice jib. [7] Method for erecting the counter boom of a crane according to any one of the preceding claims, characterized by , that the rope adjustment (5) or tensioning device is received by the bearing point (311a) of the pressure support (311) at the beginning of the erection process of the counter boom (3) at a small erection angle of the counter boom, in order to be pushed away from the back of the counter boom (3) by means of the pressure support (311), and that the rope adjustment (5) or tensioning device lifts off the pressure support (311) independently at a defined erection angle of the counter boom (3). [8] Method according to claim 7, characterized by , that in a first step the counter boom (3) is mounted together with the pressure support (311) on the upper structure (12). [9] Method according to claim 8, characterized by , that after mounting the counter boom (3) the pressure support (311) is folded forward towards the tip of the counter boom, the rope adjustment (5) is connected to the guying and placed on the bearing point (311a) of the pressure support (311). [10] Method according to claim 9, characterized by , that by retracting the retraction mechanism of the rope adjustment (5) the pressure support (311) is erected and the bracing is tensioned. [11] Method according to any one of the preceding claims 7 to 10, characterized by , that the counter boom (3) is erected by retracting the retraction mechanism (5a) of the rope adjustment (5). [12] Method according to any one of claims 7 to 11 above, characterized by, that the pressure support (311) is only connected to the rope adjustment (5) or the guying for the purpose of erecting the counter boom (3).

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