EP3184478B1 - Crane - Google Patents

Description

The present invention relates to a crane, in particular a tower crane, with at least one truss beam comprising a plurality of longitudinal belts which are interconnected by transverse and / or diagonal bars, wherein at least one of the longitudinal belts has a belt cross section varying over the belt length and / or in different truss fields has different strap cross sections.

In cranes such as cranes or port cranes structural parts of the crane structure are often designed as a truss, in which longitudinal straps are connected by transverse or diagonal bars. In tower cranes tower elements and cantilever and counter-jib parts may be formed in the form of such a framework support. In other types of cranes such as mobile telescopic cranes with luffing boom cantilever extensions such as luffing tips in the form of such framework support can be formed. In other cranes such as derrick cranes and the like structural parts in the form of truss or truss girders are formed. Such cranes with trusses are for example from the writings EP 0 928 769 A1 . DE 31 15 531 A1 . US 2129466 A and US 1941952 A known.

In order to achieve the lowest possible weight at the highest possible strength, it is desirable, the cross-sectional profiles of the longitudinal straps and transverse or diagonal bars to adapt to the forces prevailing in the respective framework field forces in order to make the best possible use of the material cross-sections and the associated strengths. In the case of the longitudinal straps, this means that they should have different cross sections per se in different longitudinal sections or in different framework fields, since different tensile forces act on the longitudinal straps in different framework fields. To meet this requirement, it has been proposed to assemble a longitudinal belt of different belt parts and to weld the belt sections together. However, such welds are not easy to manufacture, especially when high strength steels are used. On the other hand, the production costs also increased by a more complex storage, since different rod parts must be kept.

In order to avoid this complex manufacturing effort, the longitudinal straps of the trusses of cranes are therefore often made in practice with constant cross-section in order to use a continuous belt can. In order to meet the strength requirements, however, the belt cross-section must be chosen so that it can withstand the forces that occur in a most heavily used framework field, which then leads to oversizing in weaker sized stringer fields and a corresponding increase in weight.

It has already been proposed that the straps and rods of such a crane truss support no longer made of steel profiles, but to use other, in particular fiber-reinforced materials such as carbon fiber and / or aramid fiber reinforced profile parts. In addition to quite high production costs such fiber material parts without special protective measures sometimes have disadvantages in impact and shock resistance, which is problematic especially for frequently assembled and dismantled fast-erecting cranes, which are often subject to rather rough conditions during transport and assembly.

The present invention is therefore based on the object to provide an improved crane of the type mentioned, which avoids the disadvantages of the prior art and further develops the latter in an advantageous manner. In particular, a high-strength, weight-optimized framework support is to be created, which can be produced with a simple manufacturing effort and used on various crane forms, including frequently erected and dismantled fast-erecting cranes.

According to the invention, said object is achieved by a crane according to claim 1. Preferred embodiments of the invention are the subject of the dependent claims.

To solve the above object, it is proposed to adapt the longitudinal belt cross sections to the force relationships prevailing in the different beam sections without welding together the longitudinal belt sections of different cross section from a plurality of belt parts, but at least in sections to form the longitudinal belt in one piece or in material homogeneity in one piece despite changing cross section. According to the invention, the at least one longitudinal belt, which has a belt cross-section varying over the length or different belt cross-sections in different truss fields, has weld-free transitions between belt sections of different belt cross-section. At least two belt sections of different cross-section are made of one piece in a material-homogeneous manner and free of connecting seams, wherein said longitudinal belt can be made in particular of steel or a steel profile or a semi-finished steel product. In this case, said longitudinal belt is adapted not only in terms of its Gurtquerschnitts to different frame support sections, but also has a curved and / or beveled course, for example - when the longitudinal belt is used as the upper belt - to make the height of the truss bearer different in different framework support sections different, in particular a cantilever tip to taper and / or next to a constant in height Stabwerkträgerabschnitt provide a rod support section with increasing or decreasing height and / or provide rod support sections with different degrees of height change.

In an advantageous development of the invention, the longitudinal belt is also free of weld seams in the transition regions between bent or curved longitudinal belt sections, so that a material-homogeneous, integrally one-sided bending or bending region results.

The truss with such a longitudinal belt with weld-free transitions between belt sections of different cross-section can basically be used for various crane parts or structural parts of cranes, especially in the area of tower and jib parts. In particular, a truss beam formed in the above-mentioned manner can be used as a boom or outrigger part of a crane, wherein the longitudinal belt with the various belt cross-sections and weld-free transitions can form the top flange of the jib part therebetween. In general, however, the truss beam can also be used in other crane beam parts, in which case the longitudinal belt formed in the above-mentioned manner is particularly advantageous if this belt constitutes the main belt or such a main tension belt that is essentially only operationally tension-stressed.

In particular, the rod carrier formed in the manner mentioned can form a cross-sectionally generally triangular cantilever or cantilever part, in which at least the upper girth has lengthwise changing strap cross sections with transitions free of weld seams and is supplemented by two lower girders which together and with said upper girth are connected by transverse and / or diagonal struts.

In a further development of the invention, said at least one longitudinal belt in the framework fields between connected transverse and / or diagonal struts different, each adapted to the tensile forces in the respective framework field Gurtquerschnitte, in particular such that in bar structures with higher tensile forces on the longitudinal belt of this one thicker or larger belt cross-section owns and has lower Gurtquerschnitte in bar work fields with lower tensile forces.

In principle, the belt cross-section of the longitudinal belt can also be located within a framework field, i. between two adjacent connection points of transverse or diagonal braces, change. Advantageously, however, the longitudinal belt has within a respective framework field a substantially constant belt cross-section. The belt cross-sections change from the field of the tarmac to the tarmac and are optimally adapted to the prevailing load in each tarmac field. The cross-sectional changes can be provided in the region of the articulation points or attachment regions of the transverse or diagonal struts.

In a further development of the invention, the longitudinal belt can comprise at least one connection point of a transverse and / or diagonal bar a profile widening, from which the belt cross-section on both sides - viewed in the belt longitudinal direction - tapers. By such profile widening in the region of the connection points of transverse and / or diagonal struts welding connections of said transverse and / or diagonal struts can be provided in a voltage-reduced area, i. the cross-sectional core of the longitudinal belt also remains free of weld seams in the area of the connection of transverse and / or diagonal struts.

The belt cross-section of said longitudinal belt can thereby decrease in at least a part of the framework support of the framework field to the framework field. In particular, the belt cross section may decrease in a direction of the longitudinal belt from the stringer field to the strut field to the projecting end of the cantilever part, if the cantilever part is a cantilever tip or a cantilever tip part. Depending on how the forces in the framework fields, in particular the tensile forces on the upper flange, arise, other cross-sectional gradations or courses may be useful.

In an advantageous embodiment of the invention, said longitudinal belt with the changing belt cross-sections with weld-free transitions between the profile sections or cross-sectional changes may be formed from a band steel part or a solid material profile part with an approximately rectangular cross-section. The use of a flat steel semifinished product makes it possible to use a longitudinal belt that runs through at least part of the jib part, the cross section of which varies in a simple manner and can therefore be adapted to the forces prevailing there for different truss fields.

In particular, in at least one belt section, said longitudinal belt can have a belt width that changes over the length while the belt height remains substantially constant. When a flat steel strip member is used in the aforementioned manner, the thickness of the strip steel part remains substantially constant over the length, while cross-sectional tapers are obtained by varying the strip width.

Fig. 1:

eine schematische Seitenansicht eines Krans in Form eines als Turmdrehkran ausgebildeten mobilen Schnelleinsatzkranes, dessen Turm einen Ausleger trägt, der als Stabwerkträger ausgebildet ist,

Fig. 2:

eine schematische Seitenansicht eines als Stabwerkträger ausgebildeten Auslegerteils, das die Auslegerspitze mit zur Spitze hin kleiner werdender Stabwerkträgerhöhe zeigt,

Fig. 3:

eine Draufsicht auf den Auslegerteil aus Fig. 2, die den Obergurt und dessen Querschnittsverlauf zeigt,

Fig. 4:

eine vergrößerte, ausschnittsweise Draufsicht auf den Obergurt des Auslegerteils aus den vorhergehenden Figuren, und

Fig. 5:

eine vergrößerte, ausschnittsweise Seitenansicht des Obergurts des Auslegerteils aus den vorhergehenden Figuren.

The invention will be explained in more detail below with reference to a preferred embodiment and associated drawings. In the drawings show:

Fig. 1:

a schematic side view of a crane in the form of a designed as a tower crane mobile fast-erecting crane, the tower carries a boom, which is designed as a truss girder,

Fig. 2:

FIG. 2 is a schematic side view of a jib part designed as a truss system, showing the jib tip with the truss height becoming smaller toward the tip; FIG.

3:

a plan view of the boom part Fig. 2 showing the upper flange and its cross-sectional profile,

4:

an enlarged, partial plan view of the upper flange of the boom part of the preceding figures, and

Fig. 5:

an enlarged, partial side view of the upper belt of the jib part of the preceding figures.

As Fig. 1 shows, the crane 1 can be designed as a mobile fast-erecting crane in the form of a tower crane, the tower 2 carries a boom 3 and is supported at its lower end on a rotating platform 4 which is rotatable about an upright axis of rotation. Said turntable 4 in turn sits on an undercarriage 5, which may be designed as a truck or otherwise movable, but may also be formed by a fixed, non-movable support base.

The boom 3 can be tilted about a horizontal transverse axis mounted on the tower 2, wherein the up and down rocking can take place via the bracing 6.

The tower 2 and the boom 3 consists of truss girders, of which at least one can be designed in the manner explained in more detail below.

In particular, a boom part, for example, the in Fig. 2 cantilever tip shown be configured as a bar support 7, which includes a plurality of longitudinal straps, which are interconnected by a plurality of transverse or diagonal struts 10. In particular, the aforementioned longitudinal straps may comprise a top flange 8 and two bottom straps 9, so that the bar support 7 has an overall triangular cross section. In principle, however, other constellations are conceivable, for example, two upper straps with two lower straps or two upper straps with a lower flange, depending on what loads the rod carrier is subjected.

At least one of the aforementioned longitudinal straps can have the training described in more detail below with changing cross sections and weld-free transitions, and this can be in particular the upper tensile force 8 subjected to the high tensile forces. The other longitudinal straps, in particular the lower straps 9 may have a uniform over the length considered Gurtquerschnitt, but may also be formed with varying cross sections analogous to the top flange 8.

As Fig. 3 and Fig. 4 show, the upper flange 8 in different framework fields 11, 12 and 13 - which are each between two articulation points 14, 15, 16 and 17 of transverse or diagonal struts 10 - have different Gurtquerschnitte. Like a comparison of Figures 2 and 5 with the Figures 3 and 4 shows, the upper flange 8 may have a substantially constant profile thickness, while the profile width varies over the length of the belt or is different from the framework field to rod work field. The profile thickness and the profile width are measured in two mutually perpendicular main axes of the cross-sectional profile, wherein the profile thickness when the truss member is a boom part, measured in the vertical direction and the profile width can be measured in the horizontal direction.

In particular Fig. 4 shows, the profile width to the jib tip from rod field to rod work field can be smaller, in particular from B1 on B2 and B3 decrease to B4, see. Fig. 4 ,

In the region of the articulation points 14, 15, 16 and 17 of the transverse or diagonal struts 10, the belt may have profile widenings 18, which may be formed in particular in the form of cross-sectional widenings, cf. Fig. 4 , wherein also in the area of the profile widenings 18, the profile thickness can remain constant.

Advantageously, the cross-sectional transitions, in particular also in the region of the profile widenings 18, have low-profile, in particular rounded contouring, in order to prevent any voltage peaks. By the mentioned profile widening 18, the transverse or diagonal struts 10 can be welded in low-tension edge portions of the upper belt 8.

As Fig. 3 and Fig. 4 show, the upper flange 8, despite its varying Gurtquerschnitte over the entire length of the jib part or truss 7th be formed integrally without weld joints in the transition areas or in the sections of a framework field itself. In particular, said longitudinal belt 8 can be made of a flat steel profile with a solid material cross section.

As Fig. 5 shows, the upper flange 8 may include one or more folds 19, whereby the height of the boom part can be adjusted as desired in a desired manner, in particular can be tapered towards the boom tip. The mentioned folds 19 are advantageously made perpendicular to the shorter main axis of the Gurtquerschnitts, ie when extending the larger width in the horizontal direction, the profile is bent or bent in the vertical direction.

Advantageously, the upper flange 8 can also be formed free of weld seams in the transition regions of the abovementioned folds 19, so that the belt can also extend over the folds 19 in a material-homogeneous manner and integrally in one piece.

In a further development of the invention, the top chord 8 may have a longitudinal chord or a central material core, which extend over the entire length of the top chord away weld seam or material homogeneous, integrally formed integrally.

The top flange 8 can - as the bottom straps 9 and possibly also the transverse or diagonal struts 10 - be made of high strength steel, which is particularly useful, because little welding joints are necessary or changes in direction formed by folds and / or cross-sectional changes the blank shape can be formed.

In addition, simple planned bending points in the truss 7 or boom can be installed in a simple manner.

Furthermore, savings in storage can be achieved because only one sheet metal profile or strip steel profile must be kept ready for the top flange.

• Einfache Anpassung der Profilbreite bzw. des Profilquerschnitts an den statisch erforderlichen Gurtquerschnitt und damit Leichtbau;
• es sind keine Schweißverbindungen zwischen den Obergurtfeldern notwendig, obwohl sich der Querschnitt verändert;
• es können kerbarme Profilaufweitungen an den Stellen vorgesehen werden, an denen andere Trägerteile wie beispielsweise Quer- und Diagonalstreben oder Anschlusslaschen angeschweißt werden müssen;
• eine einfache Fachwerkhöhenveränderung ist durch Abkanten des Obergurts erreichbar;
• es ist auf einfache Art möglich, ein Obergurtfeld so zu gestalten, dass es bei einer Kranfehlbedienung beispielsweise bei der Kranmontage als erstes Teil ausknickt, so dass das kostengünstigste Auslegerteil als erstes versagt;
• es kann ein extrem schlankes Obergurtprofil und eine hierdurch bedingte geringe seitliche Windangriffsfläche erzielt werden, so dass ein relativ kleinerer Drehwerkantrieb ausreichend ist.

The Längsgurtausbildung or -form described in the context of the present application allows in particular the following advantages:

• Easy adjustment of the profile width or the profile cross-section of the statically required belt cross section and thus lightweight construction;
• no welds between the upper belt panels are necessary, although the cross section changes;
• Kerbarme profile widening can be provided at the locations where other support members such as transverse and diagonal braces or connecting straps must be welded;
• a simple truss height change can be achieved by folding the upper belt;
• it is easily possible to design a Obergurtfeld so that it kinks in a crane malfunction, for example in the crane assembly as the first part, so that the most cost-effective boom part fails first;
• It can be achieved an extremely slim Obergurtprofil and thereby caused low lateral windage surface, so that a relatively smaller rotary drive is sufficient.

Claims (10)

1. A crane, in particular a tower slewing crane, having at least one lattice boom (7) that comprises a plurality of longitudinal beams (8, 9) that are connected to one another by transverse and/or diagonal struts (10), wherein at least one of the longitudinal beams (8) has a beam cross-section varying over the beam length and/or has different beam cross-sections in different lattice fields (11, 12, 13), with the at least one longitudinal beam (8) having transitions free of weld seams between beam sections of different beam cross-sections, characterized in that the at least one longitudinal beam (8) has an at least simply edged and/or bent longitudinal axis, with a transition free of weld seams being provided between the mutually edged or bent beam sections
2. The crane in accordance with the preceding claim, wherein the at least one longitudinal beam (8) forms the upper beam of a boom part and/or a main beam of the lattice boom (7) subjected primarily to tension.
3. The crane in accordance with one of the preceding claims, wherein the at least one longitudinal beam (8) has different beam cross-sections respectively adapted to the tensile forces in the respective lattice field (11, 12, 13) between connected transverse and/or diagonal struts (10) in the lattice fields (11, 12, 13), with the beam cross-section in a respective lattice field (11, 12, 13) remaining substantially constant over the beam length.
4. The crane in accordance with one of the preceding claims, wherein the beam cross-section of the named longitudinal beam (8) decreases from lattice field to lattice field at least in a part of the lattice boom (7) in one direction, in particular in a boom tip part toward the projecting end.
5. The crane in accordance with one of the preceding claims, wherein the longitudinal beam (8) is formed as a strip steel part and/or as a solid material sectional part having an approximately rectangular cross-section.
6. The crane in accordance with the preceding claim, wherein the longitudinal beam is aligned with its shorter main axis in a vertical plane.
7. The crane in accordance with one of the preceding claims, wherein the named at least one longitudinal beam (8) is produced from a preferably high-tensile steel.
8. The crane in accordance with one of the preceding claims, wherein the at least one longitudinal boom (8) has a beam width (B1, B2, B3) varying in the longitudinal beam direction with a beam height (H) that remains constant.
9. The crane in accordance with one of the preceding claims, wherein the longitudinal beam (8) comprises a section widening portion (18) at at least one connector point (14, 15, 16, 17) of a transverse and/or diagonal strut (10), with the beam cross-section decreasing, viewed in the longitudinal beam direction, at both sides from said section widening portion.
10. The crane in accordance with the preceding claim, wherein the longitudinal beam (8) has low-notch, in particular rounded, contour transitions toward the section widening portions (18).

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