Large crane with boom

Abstract

This invention relates to a large crane with an at least two-part main boom, wherein a lower and an upper part of the main boom are pivotally coupled to each other an articulation point. The invention furthermore is directed to a method for erecting or depositing a corresponding large crane.

Claims

1. A method for erecting or depositing a crane, the method comprising the following steps: providing a lower part of a main boom in a horizontal position; providing an upper part of the main boom in a horizontal position stacked with the lower part, wherein the lower part and the upper part pivotally coupled to each other at an articulation point positioned on a first side of the main boom which faces a direction which the crane is loaded; pivoting the upper and the lower part between an erected state and a deposited state of the main boom to position the upper part and the lower part one above the other, and in the deposited state, the upper part of the main boom is disconnected from a second bracing rod; and luffing the lower part of the main boom by retracting a luffing drive, then connecting the upper part of the main boom to the second bracing rod, and then luffing the upper part of the main boom by contracting a length adjuster of an articulation point bracing, the articulation point bracing comprising: a first end of a first bracing rod connected to a first bracing support and an opposite end of the first bracing support connected to the lower part of the main boom at the articulation point, a first end of the second bracing rod connected to a second bracing support and an opposite end of the second bracing support connected to the lower part of the main boom at the articulation point, and the length adjuster connected to the first bracing support and the second bracing support, wherein contracting the length adjuster reduces a distance between the bracing supports, the contraction of the length adjuster brings the upper part and the lower part of the main boom into contact forming a hard stop for the articulation point, and the contraction of the length adjuster compresses a side of the main boom opposite the articulation point.

2. The method according to claim 1, wherein the upper part is mounted and/or demounted below the lower part.

3. The method according to claim 1, wherein a fly jib is mounted to or demounted from the main boom in a partly erected state of the main boom.

4. The method of claim 1, further comprising luffing the lower part of the main boom by retracting a luffing drive, the luffing drive attached to a derrick boom or an erecting trestle at a first end and the lower part of the main boom at a second end.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) Further details and advantages of the invention will be explained with reference to the exemplary embodiments shown in the Figures. In the drawing:

(2) FIG. 1a: shows a large crane known from the prior art in a deposited state;

(3) FIG. 1b: shows a large crane according to the invention in a deposited state;

(4) FIG. 1c: shows a large crane known from the prior art in an erected state;

(5) FIG. 1d: shows a large crane according to the invention in an erected state;

(6) FIGS. 2a-2e: show the erection or deposition of a large crane according to the invention.

DETAILED DESCRIPTION

(7) FIG. 1b shows a large crane according to the invention in a state with a deposited main boom 11. Here, it can be seen that the space required for assembly according to the invention is very much shorter when using the method or crane according to the invention.

(8) According to the invention, the main boom 11 of the boom system 10 has an articulation point 113. This articulation point 113 divides the main boom 11 into a lower part 110 and an upper part 111. The lower part 110 is arranged closer to the uppercarriage 4 or coupled directly to the uppercarriage 4. The upper part 111 is coupled to the uppercarriage 4 of the large crane by means of the lower part 110.

(9) Thus, a so-called erection flipped down can be realized. First of all, the upper part 111 is assembled from the individual lattice pieces while lying on the ground or being suitably supported. The free end of the main boom 11 is located in the vicinity of the undercarriage 3. Thereafter, the lower part 110 is assembled from the individual lattice pieces. The lattice pieces of the lower part 110 can be supported on the lattice pieces of the upper part 111. The articulation piece of the main boom 11 is connected to the uppercarriage 4 at its swivel axis.

(10) Alternatively, the lattice pieces of the lower part 110 might also at least partly be mounted beside the upper part 111. Thereafter, they would then be lifted by means of the bracing 141 and be swivelled into their mounting position on the upper part 111. For this purpose, the crane lifts the lower part. The lower part 110 and the upper part for example are connected by means of a cable. Hence, the upper pan 111 also is lifted. As the upper part is shorter, the same rotates about its contact surface on the ground and swivels below the lower part 110 of the main boom.

(11) The erection method of the invention also requires a derrick boom 14 or at least an erecting trestle. As is known from the prior art, the connection between derrick boom 14 and main boom 11 serves as luffing drive 141 of the boom system 10 about its swivel axis. Hence it is variable in length. During crane operation, the angle of the derrick boom 14 generally remains unchanged. It can, however, also be adaptable.

(12) The use of the method of the invention only with an erecting trestle represents a subordinate alternative. The lengths in boom systems which can be erected only by means of the erecting trestle and hence with a smaller lever arm are not problematic as such. Accordingly, the erecting trestle or the derrick boom can serve as the only erecting element for the main boom 11, depending on the length of the boom system.

(13) In contrast to the systems known from the prior art, the lulling drive 141 is connected to the lower part 110 of the main boom 11 in the region of the articulation point 113. To erect the boom system 10, a winch retracts the luffing drive 141. The lower part 110 of the main boom 11 luffs up about its swivel axis. The same entrains the upper part 11 at the articulation point 113. The free end of the main boom 11 can roll along on a carriage 5, as this is shown for example in FIG. 2b. The lower part 110 continues to slew, until the upper part 111 is freely or approximately freely suspended at the articulation point 113. In this condition, the fly jib 12 can be mounted with its holding system 13 at ground level. This is illustrated for example in FIG. 2c.

(14) In this position, the articulation joint bracing 114 also is used. The articulation point bracing 114 consists of bracing rods 1141 and 1142 unchangeable in length, at least two bracing supports 1143 and 1144 and the length adjuster 1145. The bracing rods 1142 unchangeable in length are connected to the upper part 111 of the main boom 11.

(15) As shown in FIG. 2d, the upper part 111 now can also be luffed up by retracting the length adjuster 1145. The fly jib 12 can be guided on a carriage. It continues to slew, until the holding system 13 holds it in its working angle relative to the main boom 11. By further retracting the length adjuster 1145, the main boom 11 reaches its working position which is shown in FIG. 2e.

(16) As to the articulation point 113, it should be mentioned that it is located on the side of the main boom 11 facing the load. Under a tensile load, the elements lower part 110 of the main boom 11, bracing support 1143 and bracing rods 1141 unchangeable in length form a stable triangle, just like the elements upper part 111 of the main boom 11, bracing support 1144 and the bracing rods 1142 unchangeable in length. Both triangles are pulled together by the length adjuster 1145 around the articulation point in such a way that the main boom 11 is compressed on its side facing away from the load. This contact point hence can be pretensioned to a hard stop.

(17) Alternatively, there can also be provided a resilient element like a storage cylinder/hydraulic cylinder or a spring. There is not produced a flexurally rigid connection. The load then is standing on the length adjuster 1145.

(18) It should be noted that both bracing supports 1143 and 1144 can be articulated to the lower part 110 of the main boom 11. This is illustrated for example in FIG. 2a.

(19) A frequently used additional bracing 200, as it is shown in FIG. 1c, can be omitted in many cases. The bracing according to the invention with its bracing trestles fulfills this task. The difference between FIG. 1c and FIG. 1d is the shortening of the rod with the free length. The articulation point 113 acts like a knot. Nevertheless, an additional bracing theoretically might be used here as well.

(20) In the erected state of the main boom 11, the intermediate angle between lower part 110 and upper part 111 can be a few degrees. When the angle is 0, the drive of the upper part 111 according to the invention pulls to the rear on application of the above-mentioned pretension and bends the main boom 11 to the rear. When the intermediate angle is too large, the minimum achievable outreach (forced outreach) becomes too large and the maximum lifting capacity is negatively influenced by the lever arm.

(21) Both parts 110, 111 can have separate protractors which transmit their data to the crane controller. Thus, all angles are always known and can be approached selectively. This is particularly advantageous when depositing the main boom 11 with the articulation point 113. The method here is carried out in reverse order. The positions hence are not always obtained automatically (e.g. hanging upper part 111), but must be controlled and approached under supervision. Further sensors also are provided for monitoring purposes. This can be force sensors and/or position sensors.

(22) During the assembly of the two main boom parts, chains can be used for aligning the two parts 110, 111. When aligning the two main boom parts 110, 111 receptacles may also become necessary for pre-centering. Both parts to be assembled are very large and heavy, so that suitable stops and guide plates might be mounted on the one part into which the protrusions of the other main boom part enter and, during further lifting, run along the guide plates and align the two parts relative to each other.

(23) The articulation points of the bracing and the position of the knot main boom 11 formed by the articulation point 113 are to be suitably chosen from a static point of view. In this way, the maximum achievable length of the boom system can yet be increased.

POSITION NUMBERS

(24) crane 1 boom system 10 main boom 11 lower part 110 upper part 111 articulation point 113 articulation point bracing 114 bracing rods 1141 and 1142 unchangeable in length bracing supports 1143 and 1144 length adjuster 1145 fly jib 12 holding system 13 bracing 131 and 132 bracing support 133 derrick boom 14 luffing drive 141 ground 2 spacers 21 undercarriage 3 uppercarriage 4 carriage 5