EP2504267B1 - Mobile telescopic crane - Google Patents

Description

The invention relates to a mobile telescopic crane according to the preamble of claim 1.

From the EP 1 354 842 A2 a mobile telescopic crane is known, which has two brackets arranged on the boom and inclined to the rocker plane. The guy supports are connected to increase the load capacity of the mobile telescopic crane via guy ropes with the free end of the boom and the superstructure. As a result, laterally acting on the boom loads that can represent the traglastbegrenzende criterion in an operating position of the boom can be better absorbed. A disadvantage of this mobile telescopic crane that the guy supports represent a significant additional weight. The guy supports must therefore be transported separately on a truck to the site and mounted there on the boom. This is associated with a considerable cost and time.

From the RU 2 106 295 C1 is a mobile telescopic crane is known, the boom is composed of two juxtaposed sub-arms.

From the GB 2 387 373 A For example, there is known a material handling machine having a traveling machine frame and a telescoping boom pivotally mounted thereon. The boom is constructed of a plurality of boom sections, wherein a receiving fork for a load to be moved is disposed on the outermost boom section. The boom sections are telescopically designed so that the boom can be moved out and in to position the receiving fork with the boom thereon Load to and from the machine frame. In order to reduce the tilting moment about a front axis of the material handling machine, at least one boom section is made of a composite material. As a result, the weight of the boom and thus the Tipping moment around the front axle reduced. The outermost boom section is constructed, for example, of three partial boom sections of composite material.

The invention has for its object to provide a mobile telescopic crane, which allows a simple way to increase the load.

This object is achieved by a mobile telescopic crane with the features of claim 1. By the boom of at least three spaced-apart and rigidly interconnected sub-arms is constructed, the area moment of inertia of the boom is significantly increased. The area moment of inertia, which is a measure of the bending stiffness, results, according to Steiner's theorem, from the own shares of the sub-cantilevers and their Steiner shares. Due to the rigid connecting elements that connect the sub-boom sections of the sub-boom to boom sections, the boom is extremely rigid, so that the cross-sectional area remains substantially flat under load of the boom, whereby the Steiner shares in the calculation of the area moment of inertia substantially with their theoretical Values, possibly reduced by reduction factors, can be applied. In addition, a high rigidity is achieved in the extended operating position of the boom by the mechanical locking of each adjacent boom sections, since the built-up of the sub-boom sections sub-arms are extremely rigid by the lock. Preferably, each adjacent sub-boom sections of each sub-boom are mechanically locked to each other. The locking takes place for example by means of locking bolts, which are hydraulically, pneumatically or electromechanically actuated. Alternatively, the locking can be done by means of a bayonet-type locking mechanism.

By the at least three partial boom high rigidity of the boom is ensured both opposite to perpendicular to the rocker plane and acting in the rocker bending forces. If the jib has exactly three sub-jibs, then these jacks can be arranged in a triangular manner, whereby the stiffness can be adjusted over the width and height of the jib relative to the rocker plane perpendicular to the rocker plane and to bending forces acting in the rocker plane. The same applies if the boom has at least four, in particular exactly four sub-arms.

Due to the significant increase in the area moment of inertia or the area moments of inertia of the boom according to the invention can be completely different dimensions than conventional boom, so that in comparison to a conventional boom with guy supports a corresponding increase in the load with a lower additional weight can be achieved. By the sub-arms are constructed of telescoping part-boom sections in the longitudinal direction, the boom can be brought from a transport position to an operating position with little effort. Due to the lower additional weight of the mobile telescopic crane according to the invention - drive within a certain load class - with the full boom on public roads to the site, so that in contrast to a boom with guy supports no separate transport and no complex installation is required. The inventive mobile telescopic crane thus enables a simple way to increase the load.

In addition, the boom according to the invention can be dimensioned such that in comparison with a conventional boom with guy supports again a significant increase in the load can be achieved is. In this case, the boom according to the invention also has a considerable weight, so that the mobile telescopic crane with the boom according to the invention may no longer be able to participate fully in public traffic. Individual sub-cantilevers or a group of sub-cantilevers or the entire boom must then be transported separately to the site and mounted there. In the described dimensioning of the boom according to the invention, the advantage is thus in the increase of the load.

By the number of sub-arms and their arrangement and distance from each other a variety of optimization parameters are given, so that the boom according to the invention can be optimized in terms of its bending stiffness perpendicular to and / or parallel to the rocker plane and / or in terms of weight. Depending on the load class in which the mobile telescopic crane according to the invention is to be located, the boom according to the invention can be optimized with regard to its weight and / or with regard to its bending stiffness or load capacity. The mobile telescopic crane according to the invention preferably has a boom with at least three, in particular at least four, and in particular at least five boom sections or respective partial boom sections.

A mobile telescopic crane according to claim 2 ensures a high rigidity of the boom against bending loads. The respective partial cross-sectional area comprises the material cross-sectional area as well as the cavity cross-sectional area bounded by the material of the sub-arm.

A mobile telescopic crane according to claim 3 has an increased rigidity against bending forces acting perpendicular to the rocker plane. The

Width B _A is a maximum width of the boom or of the respective boom section.

A mobile telescopic crane according to claim 4 has an increased rigidity against bending forces acting in the rocker plane. The height H _A is a maximum height of the boom or the respective boom section.

A mobile telescopic crane according to claim 5 ensures a similar stiffness behavior of the boom in the positive and negative lateral direction.

A mobile telescopic crane according to claim 6 allows an optimization of the rigidity of the boom in relation to its weight.

A mobile telescopic crane according to claim 7 ensures a compact transport position of the boom. The possible change in the height of the boom, if necessary, ensures, in particular, that the mobile telescopic crane does not exceed a maximum permissible height when driving. For example, the at least three partial arms can be linearly displaceable or pivotable relative to one another. The sub-arms are fixable to each other in a displaced operating position. This is done in particular by means of mechanical locking units. The mechanical locking units are arranged, for example, on the connecting elements.

A mobile telescopic crane according to claim 8 ensures telescoping of the boom part. Characterized in that in the longitudinal direction adjacent sub-boom sections are each telescopically telescoping or telescoping guided, telescoping of the boom sections is achieved in a simple manner in conjunction with a high rigidity of the boom.

A mobile telescopic crane according to claim 9 is simple. For example, the partial boom sections have a circular cross section.

A mobile telescopic crane according to claim 10 ensures a high rigidity of the boom, so that the cross-sectional area remains flat under load of the boom and the Steiner shares in the calculation of the area moment of inertia can be set approximately with their theoretical values.

A mobile telescopic crane according to claim 11 enables in a simple manner a mechanical locking of adjacent sub-boom sections. The respective locking bolt is hydraulically, pneumatically or electromechanically actuated, for example. Preferably, all adjacent sub-boom sections of each sub-boom are mechanically locked to each other by means of at least one locking bolt. If the boom has exactly three partial arms, then the partial boom arranged in the rocker plane can preferably be mechanically locked from the inside to the outside, whereas the partial arms arranged at a distance from the rocker plane can preferably be mechanically locked from outside to inside. This means that two adjacent sub-boom sections of the sub-boom arranged in the rocking plane can be locked in such a way that the at least one locking bolt for locking is first guided through the inner boom section and then through the outer boom section. Accordingly, vice versa is used in neighboring Part-boom sections of spaced apart from the rocker plane sub-arm of the at least one locking bolt initially guided by the outer part boom section and then by the inner part boom section.

A mobile telescopic crane according to claim 12 allows rapid mechanical locking of adjacent sub-boom sections. Each locking bolt only has to be guided through two associated locking bores of the adjacent sub-boom sections in order to mechanically lock them to one another. The distance to be traversed for locking the respective locking bolt is low. Due to the fact that the respective locking bolt only has to be guided by two associated locking bores, a comparatively low accuracy in the alignment of the respective locking bolt is required. Preferably, exactly two locking bolts are provided, which are arranged opposite to each other and can be actuated in opposite directions.

A mobile telescopic crane according to claim 13 ensures a high rigidity against bending forces acting perpendicular to the seesaw plane. If the at least two sub-arms with the greatest distance to the rocker plane would be arranged on an underside of the jib facing the undercarriage, so that the width of the jib would decrease from its underside to its upper side, then the at least two lower-part jibs would Both due to acting in the rocker bending forces and due to acting perpendicular to the rocker bending forces are charged to pressure. Such a structure of the boom would be due to the double pressure load according to the Euler kinks to an undesirable load limitation of the boom or the mobile telescopic crane lead. To avoid this, the at least two sub-arms are arranged with the greatest distance to the rocker plane on the upper side of the boom facing away from the undercarriage, so that bending forces acting in the rocker plane essentially lead to a tensile load of the at least two upper-part booms, whereas perpendicular to the rocker plane acting bending forces lead to a pressure load of the upper part boom. The pressure load on the furthest to the rocker plane spaced sub-arms can thus be significantly reduced. The area moment of inertia is thus increased on the one hand in accordance with the invention, but on the other hand avoided a double pressure load. By increasing towards the top width so optimal bending stiffness of the boom is achieved with respect to perpendicular to the rocker plane acting bending forces. Since the space in the transport position of the boom at the top is not substantially limited, the width of the boom can be dimensioned at the top in wide areas as needed. In exactly three sub-arms an undercarriage-facing, lower part of the boom is arranged in the rocker plane and two facing away from the undercarriage, upper part boom spaced from the rocker plane, so that the width of the boom from the lower part boom or the underside of the upper part of the cantilevers and the top increases. If the jib has exactly four sub-jibs, then these are trapezoidally arranged, so that the width of the jib increases from two sub-jibs facing the undercarriage to two upper sub-jibs facing away from the undercarriage. The lower part boom thus have a smaller distance to the rocker plane, as the upper part boom. Since the pressure load due to acting perpendicular to the rocker plane bending forces decreases with the distance to the rocker plane, is also at a cantilever with trapezoidally arranged sub-arms optimizes the bending stiffness with respect to bending forces acting perpendicular to the seesaw plane.

A mobile telescopic crane according to claim 14 has a relatively stiff and simple construction boom.

A mobile telescopic crane according to claim 15 ensures that the arranged in the rocker sub-boom can be articulated according to conventional boom on the superstructure. In addition, the arranged in the rocker sub-boom can serve as a receiving space for the hydraulic cylinder for telescoping the boom. Furthermore, the arranged in the rocker sub-boom due to its partial cross-sectional area A ₁ record high acting in the rocker bending forces. The flexural rigidity of the boom is thus correspondingly high. For the ratio of the partial cross-sectional area A ₁ to the partial cross-sectional area A ₂ or A _{3 of} the further sub-arm applies: A ₁ / A _i > 1, in particular A ₁ / A _i ≥ 1.5, and in particular A ₁ / A _i ≥ 2 with i = 2 and 3. Preferably, A ₂ = A ₃ .

A mobile telescopic crane according to claim 16 ensures a high bending stiffness of the boom relative to bending forces acting perpendicular to the rocker plane. Characterized in that a lower sub-boom facing the undercarriage is arranged in the rocker plane and two facing away from the undercarriage, upper part boom spaced from the rocking plane, the width of the boom of the lower part boom takes in the direction of the upper part Boom too. The width of the boom thus increases from its underside towards the top. The arranged in the rocker lower part boom is essentially only loaded due to pressure acting in the rocker plane bending forces. Bending forces acting perpendicular to the rocker plane essentially do not result in any pressure loads in the lower part boom. In contrast, the upper and spaced to the rocker plane arranged sub-arms are not loaded due to pressure acting in the rocking plane bending forces substantially. Thus, a double pressure load due to acting in the rocker plane and perpendicular to the rocker bending forces is avoided in all sub-arms. Due to the arrangement of exactly three sub-arms, on the one hand, the area moment of inertia is increased in accordance with the invention, but on the other hand avoided a double pressure load of individual boom part due to acting in the rocker plane and perpendicular to the rocker bending forces, whereby an unwanted restriction of the load be given would. Accordingly, the bending stiffness is optimized with respect to bending forces acting perpendicular to the rocker plane by the arrangement of the sub-boom. The distance of the upper part boom to the rocker plane is variable in sizing of the boom in many areas, as in particular in the transport position of the boom, the space at the top of the boom is not limited.

A mobile telescopic crane according to claim 17 ensures a similar stiffness behavior of the boom in the positive and negative lateral direction. Furthermore, the boom is simple.

A mobile telescopic crane according to claim 18 allows an optimal design of the lower boom part with respect to acting in the rocker bending forces. The boom allows due to the cross section of the lower boom part a higher bending stiffness compared to conventional cantilevers compared to bending forces acting in the rocker plane. In particular, the compressive strength of the lower boom is significantly improved by the shape of the cross section compared to conventional cantilevers having a substantially rectangular cross-section. In addition, the weight of the boom can be optimized by the cross section of the lower boom. Preferably, the lower part cantilever has a circular or oval cross-section over the entire part-cross-sectional area. However, the cross section may, for example, for manufacturing or functional reasons, differ in sections from a circular or oval cross-sectional shape. For example, the respective cross section may be flattened in sections. If the lower part boom has an oval cross section, then for a maximum width B ₁ perpendicular to the rocker plane and a maximum height H ₁ in the rocker plane H ₁ / B ₁ > 1, in particular H ₁ / B ₁ ≥ 1.2 , and in particular H ₁ / B ₁ ≥ 1.5. Preferably, the lower sub-boom overlaps in the direction of the rocker plane with the upper sub-arms.

A mobile telescopic crane according to claim 19 allows in a simple and space-saving manner a telescoping of the boom.

A mobile telescopic crane according to claim 20 ensures a high rigidity of the boom relative to bending forces acting perpendicular to the rocker plane. By the end-locking of adjacent sub-boom sections of the upper boom part side acting bending forces are derived directly into the entire boom and absorbed by this. This is ensured, in particular, by the fact that the respective at least one locking bolt is fastened or displaceably mounted directly on the associated or adjacent connecting element.

A mobile telescopic crane according to claim 21 allows a simple and space-saving cable guide.

A mobile telescopic crane according to claim 22 ensures in the usual way the lifting of loads by means of a supporting cable. The carrying cable is guided from a free end of the boom to a cable winch arranged on the superstructure. The carrying cable is preferably guided in the cable guide channel.

Fig. 1

eine perspektivische Ansicht eines Mobil-Teleskopkrans gemäß einem ersten Ausführungsbeispiel mit einem teleskopierbaren Ausleger aus drei Teil-Auslegern, der sich in einer Transportstellung befindet,

Fig. 2

einen Querschnitt durch den Ausleger in Fig. 1 im Bereich eines Verbindungselements,

Fig. 3

eine perspektivische Ansicht des Mobil-Teleskopkrans in Fig. 1 mit dem sich in einer eingefahrenen Betriebsstellung befindlichen Ausleger,

Fig. 4

eine perspektivische Ansicht des Mobil-Teleskopkrans in Fig. 1 mit dem sich in einer ausgefahrenen Betriebsstellung befindlichen Ausleger,

Fig. 5

einen Querschnitt durch den Ausleger in Fig. 4 im Bereich vor dem Verbindungselement,

Fig. 6

einen Querschnitt durch den ausgefahrenen Ausleger in Fig. 5 im Bereich eines ersten Auslegerabschnitts zur Veranschaulichung der Anordnung der Teil-Ausleger,

Fig. 7

eine perspektivische Ansicht eines Mobil-Teleskopkrans gemäß einem zweiten Ausführungsbeispiel mit einem aus drei Teil-Auslegern aufgebauten Ausleger, der sich in einer ausgefahrenen Betriebsstellung befindet,

Fig. 8

eine perspektivische Ansicht eines Mobil-Teleskopkrans gemäß einem dritten Ausführungsbeispiel mit einem aus drei Teil-Auslegern aufgebauten Ausleger, der sich in einer Transportstellung befindet,

Fig. 9

eine perspektivische Ansicht des Mobil-Teleskopkrans in Fig. 8 mit dem sich in einer ausgefahrenen Betriebsstellung befindlichen Ausleger,

Fig. 10

eine Seitenansicht des Mobil-Teleskopkrans in Fig. 9,

Fig. 11

einen Querschnitt durch den Ausleger in Fig. 10 entlang der Schnittlinie XI-XI, und

Fig. 12

einen Querschnitt durch den Ausleger in Fig. 10 entlang der Schnittlinie XII-XII.

Further features, advantages and details of the invention will become apparent from the following description of several embodiments. Show it:

Fig. 1

a perspective view of a mobile telescopic crane according to a first embodiment with a telescopic boom of three sub-arms, which is in a transport position,

Fig. 2

a cross section through the boom in Fig. 1 in the region of a connecting element,

Fig. 3

a perspective view of the mobile telescopic crane in Fig. 1 with the boom in a retracted operating position,

Fig. 4

a perspective view of the mobile telescopic crane in Fig. 1 with the boom in an extended operating position,

Fig. 5

a cross section through the boom in Fig. 4 in the area in front of the connecting element,

Fig. 6

a cross section through the extended boom in Fig. 5 in the region of a first boom section to illustrate the arrangement of the sub-boom,

Fig. 7

a perspective view of a mobile telescopic crane according to a second embodiment with a built-up of three sub-arms boom, which is in an extended operating position,

Fig. 8

a perspective view of a mobile telescopic crane according to a third embodiment with a built-up of three sub-arms boom, which is in a transport position,

Fig. 9

a perspective view of the mobile telescopic crane in Fig. 8 with the boom in an extended operating position,

Fig. 10

a side view of the mobile telescopic crane in Fig. 9 .

Fig. 11

a cross section through the boom in Fig. 10 along the section line XI-XI, and

Fig. 12

a cross section through the boom in Fig. 10 along the section line XII-XII.

The following is with reference to the Fig. 1 to 6 a first embodiment of the invention described. A mobile telescopic crane 1 has a mobile undercarriage 2, on which an uppercarriage 3 with a counterweight 4 are arranged. The undercarriage 2 is designed in the usual way for driving on public roads. For this purpose, the undercarriage 2 on a base frame 5 on which a plurality of axles 6 are mounted thereon arranged wheels 7, which are drivable and steerable in a conventional manner. The superstructure 3 and the counterweight 4 arranged thereon are mounted rotatably on the undercarriage 2 about a rotation axis 8 running perpendicular to the base frame 5.

On the uppercarriage 3, a boom 9 is arranged, which is by means of a hydraulic cylinder 10 in a rocking plane W pivotally and in a longitudinal direction L telescopic. For this purpose, the boom 9 has three boom sections 11 to 13 which can be telescoped in and out by means of a hydraulic cylinder 14 and thus can be transferred from a retracted transport position into an extended operating position. The first boom section 11 is pivoted at the end about a horizontal pivot axis 15 pivotally mounted on the uppercarriage 3. The pivoting of the boom 9 in the rocker plane W by means of the hydraulic cylinder 10, which is spaced from the upper carriage 3 spaced from the pivot axis 15 to the boom section 11 is articulated.

The boom 9 has three sub-arms 16, 17, 18, which are each telescopically constructed from three sub-boom sections 19 to 21, 22 to 24 and 25 to 27. The hydraulic cylinder 14 is disposed within a receiving space of the sub-boom 16, which is designed to form the receiving space as a hollow cylinder. The sub-arms 16 to 18 are arranged transversely to the longitudinal direction L at a distance from each other and connected by four rigid connecting elements 28 to 31 with each other. The connecting elements 28 and 29 are respectively arranged at the end on the sub-boom sections 19, 22 and 25 and form with these the first boom section 11. The connecting element 30 is in turn on the first boom section 11 opposite end of the boom sections 20, 23 and 26th Accordingly, the connecting element 31 is disposed on a second boom section 12 facing away from the end of the boom sections 21, 24 and 27 and forms with these the third boom section 13th

The boom 9 is constructed asymmetrically to the rocker W and has a designated as a heavy line and lying in the rocker plane W boom central longitudinal axis 32. The sub-arms 16 to 18 correspondingly have associated sub-boom center longitudinal axes 33 to 35, which are arranged polygonal or triangular and symmetrical to the rocker W. The central longitudinal axes 32 and 33 are in the rocker W and have perpendicular to the rocker W a distance b ₁ = 0 and parallel to the rocker W at a distance h ₁ from each other. In contrast, the central longitudinal axes 34 and 35 have the same distances b ₂ and b ₃ perpendicular to the rocker plane W. Furthermore, the central longitudinal axes 34, 35 to the central longitudinal axis 32 a distance h ₂ and h ₃ parallel to the rocker W on.

The arranged in the rocker W and the undercarriage 2 facing lower part boom 16 thus forms a bottom of the boom 9, whereas the spaced arranged to the rocker W and the undercarriage 2 facing away, upper part boom 17, 18 a top of the boom 9 form. The boom 9 is perpendicular to the rocker W level a width B which increases from the lower boom 16 toward the upper boom 17, 18 up to a maximum width B _A. This is in Fig. 6 illustrated.

The partial boom sections 19 to 27 are designed as hollow cylinders and have a circular cross-section. Fig. 6 illustrates the cross-sectional shape of the sub-boom sections 19, 22 and 25 of the first boom section 11 and the position of these sub-boom sections 19, 22, 25 relative to each other and to the rocking plane W. The sub-boom section 19 has an outer radius R ₁ , the larger as the respective outer radius R ₂ and R _{3 of} the sub-boom sections 22 and 25. The partial boom section 19 thus has a height H ₁ = 2 * R ₁ parallel to the rocker plane W and a width B ₁ = 2 * R ₁ perpendicular to the rocker plane W. Correspondingly, the sub-boom sections 22 and 25 have associated heights H ₂ = 2 * R ₂ and H ₃ = 2 * R ₃ and associated widths B ₂ = 2 * R ₂ and B ₃ = 2 * R ₃ . The boom 9 thus has in the region of the boom section 11 a height or a maximum height H _A , which results from the sum of R ₁ , R ₂ , h ₁ and h ₂ . Furthermore, the boom 9 in the region of the boom section 11 has a width or a maximum width B _A , which results from the sum of R ₂ , R ₃ , b ₂ and b ₃ . The same results for the boom sections 12 and 13, wherein the outer radii R ₁ to R ₃ are correspondingly smaller due to the telescoping of the boom 9. For telescoping the boom 9, adjacent sub-boom sections 19 to 27 of each sub-boom 16, 17, 18 are guided into one another so as to be displaceable in the longitudinal direction L.

For the ratio of the width B _A to each of the widths B _i with i = 1 to 3, B _A / B _i ≥ 1.5, in particular B _A / B _i ≥ 2, and in particular B _A / B _i ≥ 2, 5th Furthermore, for the ratio of the height H _A to each of the heights H _i with i = 1 to 3: H _A / H _i ≥ 1.2, in particular H _A / H _i ≥ 1.5, in particular H _A / H _i ≥ 2, and in particular H _A / H _i ≥ 2.5. The same applies to the boom sections 12 and 13th

The boom sections 19, 22 and 25 have, perpendicular to the seesaw plane W, partial cross-sectional areas A ₁ , A ₂ and A ₃ which respectively result from the circular area with the associated outer radius R ₁ , R ₂ and R ₃ . The partial cross-sectional areas A _i thus each include the associated material cross-sectional areas A _Mi as well as the cavity-cross-sectional areas A _Hi bounded by the material, where i = 1 to 3. Due to the spaced arrangement of the sub-boom 16, 17 and 18 and the sub-boom sections 19, 22 and 25, the boom 9 in the region of the boom section 11 has a cross-sectional area A _A , which is greater than a sum A _{S of} the partial cross-sectional areas A ₁ to A ₃ is. The cross-sectional area A _A is in Fig. 6 illustrated by the dotted lines which each extend tangentially between adjacent sub-boom sections 19, 22, 25. The dotted lines together with the sub-boom sections 19, 22, 25 form a peripheral line of the boom section 11. The peripheral line defines the cross-sectional area A _A. Figuratively speaking, the cross-sectional area A _A , by a circumferential line forming the rope around the boom sections 19, 22, 25 taut. The same applies to the boom sections 12, 13th

For the ratio of the cross-sectional area A _A to the sum A _{S of} the partial cross-sectional areas A ₁ to A _{3, the} following applies: A _A / A _S > 1, in particular A _A / A _S ≥ 1.5, in particular A _A / A _S ≥ 2 , in particular A _A / A _S ≥ 2.5, in particular A _A / A _S ≥ 3, and in particular A _A / A _S ≥ 4. The same applies to the boom sections 12 and 13, wherein it should be noted that the sub-boom sections 20, 23, 26 and 21, 24, 27 have due to the telescoping correspondingly lower radii R ₁ , R ₂ and R ₃ .

wobei
i ein Laufindex für die Teil-Ausleger ist,
I_z,i der Eigenanteil des Teil-Auslegers i ist,
b_i der Abstand der Schwerlinie bzw. Mittellängsachse des Teil-Auslegers i von der Schwerlinie bzw. Mittellängsachse des Auslegers in y-Richtung ist, A_Mi die Material-Querschnittsfläche des Teil-Auslegers i ist,
b_i ² · A_Mi der Steineranteil des Teil-Auslegers i ist und n die Anzahl der Teil-Ausleger ist.By this construction, the boom 9 in comparison to conventional arms on a higher area moment of inertia I _{z, ges} or I _{y, ges} with respect to perpendicular to the rocker W and in the rocker W acting bending forces. The area moment of inertia I _{z, ges} with respect to perpendicular to the rocker plane W acting bending forces, ie at a bend about the z-axis, results in: $$I_{z.\mathit{ges}}={\displaystyle \underset{i=1}{\overset{n}{\Sigma }}}\left[I_{z.i}+{\mathrm{<figure-callout\; id="2"\; label="b\; i"\; filenames="imgf0010.png"\; state="\{\{state\}\}">b\; </figure-callout>}}_i^{}\cdot A_{\mathit{Wed.}}\right]$$

in which
i is a run index for the sub-arms,
I _{z, i is} the intrinsic portion of the sub-cantilever i,
b _{i is} the distance of the center of gravity of the sub-cantilever i from the center of gravity of the cantilever in the y-direction, A _{Mi is} the material cross-sectional area of the sub-cantilever i,
b _i ² · A _{Mi is} the stone fraction of the sub-boom i and n is the number of sub-beams.

Equation (1) also describes n = 3 and b ₁ = 0. Equation (1) describes the achievable area moment of inertia I _{z, ges} for an ideally rigid cantilever 9. In the practical dimensioning of the cantilever 9, a reduction factor α is the Steiner proportions to be considered, which depends on the number of connecting elements 28 to 31 and their degree of flexural rigidity.

wobei
i ein Laufindex für die Teil-Ausleger ist,
I_y,i der Eigenanteil des Teil-Auslegers i ist,
h_i der Abstand der Schwerlinie bzw. Mittellängsachse des Teil-Auslegers i von der Schwerlinie bzw. Mittellängsachse des Auslegers in z-Richtung ist,
A_Mi die Material-Querschnittsfläche des Teil-Auslegers i ist,
h_i ² · A_Mi der Steineranteil des Teil-Auslegers i ist und
n die Anzahl der Teil-Ausleger ist.Correspondingly, the area moment of inertia I _{y, ges} results with respect to bending forces acting parallel to the rocker plane W, that is to say with a bend about the y-axis, to: $$I_{y.\mathit{ges}}={\displaystyle \underset{i=1}{\overset{n}{\Sigma }}}\left[I_{y.i}+{\mathrm{<figure-callout\; id="2"\; label="H\; i"\; filenames="imgf0010.png"\; state="\{\{state\}\}">H\; </figure-callout>}}_i^{}\cdot A_{\mathit{Wed.}}\right]$$

in which
i is a run index for the sub-arms,
I _{y, i is} the intrinsic portion of the sub-cantilever i,
h _{i is} the distance of the center of gravity or center longitudinal axis of the sub-boom i from the center of gravity or the center longitudinal axis of the boom in the z-direction,
A _{Mi is} the material cross-sectional area of the sub-cantilever i,
h _i ² · A _{Mi is} the Steiner portion of the sub-boom i and
n is the number of sub-arms.

Corresponding to equation (1), an attenuation factor β must be taken into account in equation (2) for the Steiner shares.

The area moments of inertia provide a measure of the rigidity of the boom 9 relative to the respective bending forces. Due to the Steiner shares, the area moments of inertia are considerably increased compared to conventional cantilevers.

The connecting elements 28 to 31 are substantially formed as triangular plates and each have two passage openings 36, 37 for the partial boom sections 22 to 27 of the sub-arms 12 and 13. Furthermore, the connecting elements 28 to 31 each have a rectangular passage opening 38 for the sub-boom sections 19 to 21 of the sub-boom 16, which extends approximately to the central longitudinal axes 34, 35. The passage openings 38 thus form in the connecting elements 28 to 31 a cable guide channel 39 for guiding a support cable 52. The support cable 52 is guided in a conventional manner from the free end of the boom 9 to a winch 53 arranged on the uppercarriage 3. The support cable 52 is guided at the free end of the boom 9 via two pulleys 54, 55 which are rotatably supported by a support frame 56 at the free end of the boom 9.

The sub-arms 17 and 18 are displaceable relative to the sub-boom 16 parallel to the rocker plane W. For this purpose, at the end facing the uppercarriage 3, on both sides of the partial boom section 19, two hydraulic cylinders 40 are fixedly arranged on the latter and connected to the connecting element 28. Correspondingly, two hydraulic cylinders 41, which are connected to the connecting element 29, are attached to the end of the partial boom section 19. For displacing the sub-arms 17, 18 or for fixing these sub-arms 17, 18 relative to the sub-boom 16 locking units 42 are provided. The locking units 42 are integrated into the sub-boom sections 19 to 21 and the associated connecting elements 28 to 31. The Fig. 2 and 5 show, for example, to the partial boom section 19 and to the connecting element 29 associated locking unit 42. The locking unit 42 has two oppositely disposed and opening into the passage opening 38 locking holes 43 which are perpendicular to the rocker W. By associated locking bolt 44, which are feasible by locking holes 45 of the sub-boom section 19 and the locking holes 43, a locking or unlocking is possible. The locking bolts 44 are hydraulically, pneumatically or electromechanically actuated, for example.

By the hydraulic cylinders 40, 41 and the locking units 42 of the boom 9 can be transferred from a transport position to an operating position and vice versa. In the transport position, the cross-sectional area A _A or the height H _{A of} the boom 9 is reduced in comparison to the operating position, whereby the mobile telescopic crane 1 has a lower overall height. The reduction of the overall height is required, for example, in order not to exceed a maximum permitted height in road traffic.

In addition, the locking units 42 belonging to the connecting elements 29 and 30 have locking bores 46, by means of which the locking bolts 44 can also be guided. The locking holes 46 are respectively formed in the inner sub-boom portion 20 and 21, so that in the locked state, the adjacent sub-boom portions 19 and 20 or 20 and 21 are locked in the longitudinal direction L.

For locking in the longitudinal direction L further locking units 47 and 48 are provided, which are arranged in the region of the connecting elements 29 and 30. The locking units 47 and 48 are mounted or attached directly to the respectively associated connecting element 29 or 30. The locking units 47, 48 each have locking holes 49, 50 formed in the adjacent sub-boom sections 22 and 23, 23 and 24, 25 and 26, and 26 and 27. By the locking holes 49, 50, a respective locking bolt 51 is feasible, so that the desired mechanical locking of the boom sections 11 and 12 and 12 and 13 can be achieved. Alternatively, corresponding to the locking units 42, two locking bolts 51 may be provided, which are arranged opposite to each other and in each associated locking holes 49, 50 are displaced. The locking bolts 51 are hydraulically, pneumatically or electromechanically actuated, for example.

The Fig. 1 and 2 show the mobile telescopic crane 1 in the intended state for driving. The boom 9 is in a fully retracted transport position. The locking units 42, 47 and 48 are unlocked and the boom sections 11 to 13 telescoped. Furthermore, the sub-arms 17 and 18 are completely lowered by means of the hydraulic cylinders 40, 41, so that the sub-boom 16 is arranged completely in the passage openings 38. In this state, the mobile telescopic crane 1 has the lowest possible total height, so that the maximum permitted height in the road is not exceeded. Fig. 2 illustrates the transport position of the boom 9 based on a cross section through the connecting element 29th

The Fig. 3 By means of the lifting cylinders 40, 41, the sub-arms 17, 18 and the connecting elements 28 to 31 were extended relative to the sub-boom 16 parallel to the rocker plane W. The locking units 42 belonging to the connecting elements 28 and 31 are subsequently locked.

Then the boom 9 is erected by means of the hydraulic cylinder 10 in the rocker W and telescoped by means of the hydraulic cylinder 14. Fig. 4 shows the mobile telescopic crane 1 in an operating position with the fully erected and austeleskopierten boom 9. In this state, which are associated with the connecting elements 29 and 30 Locking units 42, 47 and 48 also locked, so that the boom 9 has a high rigidity. Fig. 5 shows a cross section through the adjacent to the connecting element 29 locking units 47, 48th

The boom 9 according to the invention has a high rigidity against bending forces perpendicular and parallel to the rocker plane W due to the high area moments of inertia. This can be achieved in relation to the weight of the boom 9, a significant load increase. In particular, the boom 9, even without weight gain over conventional arms or with only a slight increase in weight on a significant increase in load, which corresponds approximately to that of a conventional boom with guy supports. However, no separate transport and no complex assembly is required compared to a conventional boom with guy supports.

The following is based on Fig. 7 A second embodiment of the invention described. In contrast to the first exemplary embodiment, the sub-arms 17a, 18a are fixedly arranged on the sub-arm 16a by means of the connecting elements 28a to 31a and can not be displaced relative thereto. If this is the maximum allowable height of the mobile telescopic crane 1a is not exceeded, so a simplification of the structure of the boom 9a is possible. The fact that the connecting elements 28a to 31a are fixedly arranged on the sub-arm 16a, the locking holes 43 can be omitted. With regard to the further construction and further operation, reference is made to the description of the first embodiment.

The following is based on the 8 to 12 A third embodiment of the invention described. In contrast to the preceding exemplary embodiments, the mobile telescopic crane 1b has a boom 9b with three partial arms 16b, 17b and 18b, the partial boom 16b arranged in the rocking plane W having an oval cross-section. The connecting elements 28b to 31b accordingly have oval passage openings 38b. To guide the support cable 52, the cable guide channel 39b is formed in the connecting elements 28b to 31b above the sub-arm 16b. The sub-boom center longitudinal axis 33 of the sub-boom 16b extends at the intersection of the maximum height H ₁ and the maximum width B _{1 of} the sub-boom 16b.

The arranged in the rocker W partial boom 16b has a maximum width B ₁ perpendicular to the rocker W and a maximum height H ₁ in the rocker W, where: H ₁ / B ₁ > 1, in particular H ₁ / B. ₁ ≥ 1.2, and in particular H ₁ / B ₁ ≥ 1.5. The sub-boom 16b overlaps in the direction of the rocker plane W with the sub-arms 17b, 18b with an overlap dimension h ₁₂ or h ₁₃ , where h ₁₂ = h ₁₃ . Furthermore, h ₁₂ <R ₂ and h ₁₃ <R ₃ . The partial cross-sectional area A ₁ is in each case larger than the partial cross-sectional area A ₂ and A ₃ . Preferably, A ₁ / A ₂ ≥ 1.5, in particular A ₁ / A ₂ ≥ 2, and in particular A ₁ / A ₂ ≥ 2.5. The same applies to A ₁ / A ₃ . The boom 9b has in the region of the boom section 11b a maximum height H _A , which results from the sum of H ₁ and R ₂ minus the overlap h ₁₂ . Furthermore, the boom 9b in the region of the boom section 11b has a maximum width B _A , which results from the sum R ₂ , R ₃ , b ₂ and b ₃ . The same is true for the boom sections 12b and 13b, wherein the outer radii R ₂ and R ₃ and the maximum height H ₁ and the overlap h ₁₂ due to the telescoping of the boom 9b are correspondingly smaller.

The sub-arms 17b, 18b are arranged according to the second embodiment at a fixed distance to the sub-boom 16b. Alternatively, the sub-arms 17b, 18b according to the first embodiment may be displaceable relative to the sub-boom 16b. The hydraulic cylinder 14b for telescoping the boom 9b is disposed inside the sub-boom 16b.

The locking units 47b, 48b are fastened directly to the connecting elements 29b, 30b, so that adjacent partial boom sections 22b and 23b, 23b and 24b, 25b and 26b and 26b and 27b are mechanically lockable to each other at the end. The locking units 47b, 48b each have two oppositely disposed locking pins 51b, which are feasible by respective associated locking holes 49, 50. The locking bolts 51b are hydraulically, pneumatically or electromechanically actuated, for example.

The boom 9b has a high bending stiffness with respect to bending forces acting in the rocker plane W and bending forces acting perpendicularly to the rocker plane W. Due to its oval cross-section and its partial cross-sectional area A ₁ , the sub-arm 16 b can, in particular, absorb high bending forces which act in the rocking plane W. With regard to the further structure and further operation of the mobile telescopic crane 1b, reference is made to the preceding embodiments.

The features of the boom 9 to 9b are basically combined in any way to a boom according to the invention. In addition to the simple increase in the load by increasing the moment of inertia point the boom 9 to 9b invention further advantages over a conventional boom with guy supports. The booms 9 to 9b according to the invention can be optimized separately in each boom section 11 to 13b for the bending forces acting, so that they are received continuously along the boom 9 to 9b and not only at the end of the boom. In addition, both the transfer of the boom 9 to 9b in the operating position and their operation is extremely simple. In particular, no complex control of the biasing force of the guy ropes is required, whereby the operation is simplified and at the same time the reliability is increased, since no erroneous control of the biasing force is possible. On the number of sub-arms 16 to 17b and their arrangement and distance to each other, whereby the cross-sectional area A _{A is} defined, as well as the cross-sectional shape and the partial cross-sectional areas A _i are given a variety of optimization parameters, whereby an inventive boom 9 to 9b can be optimized in terms of the absorption capacity of perpendicular to and in the rocker plane W acting bending forces and in terms of weight. Overall, the boom according to the invention allow 9 to 9b at a predefined weight a significant increase in load over conventional booms. In particular, a significantly easier handling of the boom 9 to 9b with respect to transport and installation or transfer to the operating position over conventional booms with guy supports is possible with the same load.

Claims (22)

1. Mobile telescopic crane with

   - a movable undercarriage (2),

   - a superstructure (3) rotatably arranged on the undercarriage (2),

   - a jib (9; 9a; 9b), which is telescopic in a longitudinal direction, arranged on the superstructure (3) and is pivotable in a luffing plane, characterised
   in that the telescopic jib (9; 9a; 9b) has at least three part-jibs (16 to 18; 16a to 18a; 16b to 18b),
   in that each of the part-jibs (16 to 18; 16a to 18a; 16b to 18b) is constructed from at least two part-jib portions (19 to 27; 19a to 27a; 19b to 27b) so as to be telescopic in the longitudinal direction,
   in that part-jib portions (19 to 27; 19a to 27a; 19b to 27b) arranged at a spacing from one another transverse to the longitudinal direction each form a jib portion (11 to 13; 11a to 13a; 11b to 13b) with at least one flexurally rigid connecting element (28 to 31; 28a to 31a; 28b to 31b), and
   in that respective adjacent jib portions (11 to 13; 11a to 13a; 11b to 13b) are mechanically lockable with respect to one another in the longitudinal direction.
2. Mobile telescopic crane according to claim 1, characterised in that the jib (9; 9a; 9b), perpendicular to the luffing plane, has a cross-sectional area A_A produced by the at least three part-jibs (16 to 18; 16a to 18a; 16b to 18b) and each of the part-jibs (16 to 18; 16a to 18a; 16b to 18b), perpendicular to the luffing plane, has a part-cross-sectional area (A₁ to A₃), wherein there applies to a ratio of the cross-sectional area A_A to a sum A_S of the part-cross-sectional areas: A_A/A_S> 1, in particular A_A/A_S ≥ 1.5, in particular A_A/A_S ≥ 2, and, in particular A_A/A_S ≥ 2.5.
3. Mobile telescopic crane according to claim 1 or 2, characterised in that the jib (9; 9a; 9b), perpendicular to the luffing plane, has a width B_A and each of the part-jibs (16 to 18; 16a to 18a; 16b to 18b) has a width B_i, to the ratio of which there applies, in each case: B_A/B_i ≥ 1.5, in particular B_A/B_i ≥ 2, and, in particular B_A/B_i ≥ 2.5.
4. Mobile telescopic crane according to any one of claims 1 to 3, characterised
   in that the jib (9; 9a; 9b), parallel to the luffing plane, has a height H_A and each of the part-jibs (16 to 18; 16a to 18a; 16b to 18b) has a height H_i, to the ratio of which there applies, in each case: H_A/H_i ≥ 1.2, in particular H_A/H_i ≥ 1.5, in particular H_A/H_i ≥ 2, and in particular H_A/H_i ≥ 2.5.
5. Mobile telescopic crane according to any one of claims 1 to 4, characterised
   in that the part-jibs (16 to 18; 16a to 18a; 16b to 18b) are arranged symmetrically with respect to the luffing plane.
6. Mobile telescopic crane according to any one of claims 1 to 5, characterised
   in that the part-jibs (16 to 18; 16a to 18a; 16b to 18b) are arranged polygonally, in particular triangularly, with respect to one another.
7. Mobile telescopic crane according to any one of claims 1 to 6, characterised
   in that at least one part-jib (17, 18) is displaceable to change the cross-sectional area A_A, in particular to change a height H_A of the jib (9), with respect to at least one other part-jib (16).
8. Mobile telescopic crane according to any one of claims 1 to 7, characterised
   in that the part-jib portions (19 to 27; 19a to 27a; 19b to 27b) of all the part-jibs (16 to 18; 16a to 18a; 16b to 18b) are configured as hollow cylinders and adjacent part-jib portions (19 to 27; 19a to 27a; 19b to 27b) are in each case telescopeable into one another.
9. Mobile telescopic crane according to any one of claims 1 to 8, characterised
   in that the part-jib portions (19 to 27; 19a to 27a) of all the part-jibs (16 to 18; 16a to 18a) have a geometrically similar and, in particular, an identical cross-section.
10. Mobile telescopic crane according to any one of claims 1 to 9, characterised
    in that respective adjacent part-jib portions (19 to 27; 19a to 27a; 19b to 27b) of all the part-jibs (16 to 18; 16a to 18a; 16b to 18b) are mechanically lockable with respect to one another in the longitudinal direction.
11. Mobile telescopic crane according to any one of claims 1 to 10, characterised
    in that at least two adjacent part-jib portions (19 to 27; 19a to 27a; 19b to 27b) are mechanically lockable with respect to one another by means of at least one locking bolt (44, 51; 44b, 51b).
12. Mobile telescopic crane according to any one of claims 1 to 11, characterised
    in that at least two adjacent part-jib portions (19 to 21; 19a to 21a; 19b to 27b) are mechanically lockable with respect to one another by means of at least two locking bolts (44; 44b, 51b).
13. Mobile telescopic crane according to any one of claims 1 to 12, characterised
    in that the jib (9; 9a; 9b) has a width that changes perpendicular to the luffing plane, the width increasing proceeding from at least one lower part-jib (16; 16a; 16b) facing the undercarriage (2) up to at least two upper part-jibs (17, 18; 17a, 18a; 17b, 18b) remote from the undercarriage (2).
14. Mobile telescopic crane according to any one of claims 1 to 13, characterised
    in that the jib (9; 9a; 9b) has precisely three part-jibs (16 to 18; 16a to 18a; 16b to 18b), which are arranged triangularly and symmetrically with respect to the luffing plane.
15. Mobile telescopic crane according to claim 14, characterised in that the part-jib (16; 16a; 16b) arranged in the luffing plane has a larger part-cross-sectional area (A₁) in comparison to the further part-jibs (17, 18; 17a, 18a; 17b, 18b).
16. Mobile telescopic crane according to claim 14 or 15, characterised in that the part-jib (16; 16a; 16b) arranged in the luffing plane is arranged on a lower side and the part-jibs (17, 18; 17a, 18a; 17b, 18b) arranged spaced apart from the luffing plane are arranged on an upper side of the jib (9; 9a; 9b).
17. Mobile telescopic crane according to any one of claims 14 to 16, characterised
    in that the part-jibs (17, 18; 17a, 18a; 17b, 18b) arranged spaced apart from the luffing plane have the same, in particular circular, cross-sections and the same part-cross-sectional areas (A₂, A₃).
18. Mobile telescopic crane according to any one of claims 14 to 17, characterised
    in that the part-jib (16; 16a; 16b) arranged in the luffing plane has a cross-section, at least in portions, which is selected from the group circular and oval.
19. Mobile telescopic crane according to any one of claims 14 to 18, characterised
    in that the part-jib (9; 9a; 9b) arranged in the luffing plane forms a receiving space, in which a hydraulic cylinder (14; 14b) is arranged to telescope the jib (9; 9a; 9b).
20. Mobile telescopic crane according to any one of claims 14 to 19, characterised
    in that respective adjacent part-jib portions (22 to 27; 22a to 27a; 22b to 27b) of the part-jibs (17, 18; 17a, 18a; 17b, 18b) arranged spaced apart from the luffing plane are mechanically lockable with respect to one another at the end, in particular the at least one locking bolt (51, 51b) provided in each case to lock adjacent part-jib portions (22 to 27;
    22a to 27a; 22b to 27b) being arranged on the associated connecting element (29, 30; 29a, 30a; 29b, 30b).
21. Mobile telescopic crane according to any one of claims 1 to 20, characterised
    in that the part-jibs (16 to 18; 16a to 18a; 16b to 18b) limit a cable guide channel (39; 39b).
22. Mobile telescopic crane according to any one of claims 1 to 21, characterised
    in that a support cable (52) is guided along the jib (9; 9a; 9b), the support cable (52) being arranged, in particular, in the cable guide channel (39; 39b).

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