TELESCOPIC SECTION HAVING A VARIABLY EXTENDING FITTING EDGE

Abstract

A boom section for the boom of a telescopic crane has a lower shell and an upper shell. The lower shell and the upper shell are welded to one another, and the weld seam extends between the lower shell and the upper shell angled in at least one region to at least one section edge of the boom section.

Claims

1. A boom section for a boom of a telescopic crane, the boom section having a lower shell and an upper shell, wherein the lower shell and the upper shell are welded to one another, and wherein a weld seam between the lower shell and the upper shell extends at least in one region of the boom section at an angle to at least one section edge of the boom section.

2. The boom section in accordance with claim 1, wherein the lower shell is thicker than the upper shell.

3. The boom section in accordance with claim 1, wherein a thickness of the lower shell increases in accordance with a torque progression in the boom section.

4. The boom section in accordance with claim 1, wherein the weld seam between the lower shell and the upper shell extends along the entirety of the boom section at a constant or varying angle greater than 0 degrees to the at least one section edge of the boom section.

5. The boom section in accordance with claim 1, wherein the weld seam between the lower shell and the upper shell extends along a first part of the boom section at a constant or varying angle greater than 0 degrees to the at least one section edge of the boom section.

6. The boom section in accordance with claim 5, wherein the weld seam between the lower shell and the upper shell extends along a second part of the boom section in parallel with the at least one section edge of the boom section, and wherein the first and second parts of the boom section are contiguous.

7. The boom section in accordance with claim 1, wherein the lower shell and the upper shell are welded to one another by a laser hybrid process.

8. A boom for a telescopic crane having at least one boom section, the boom section having a lower shell and an upper shell, wherein the lower shell and the upper shell are welded to one another, and wherein a weld seam between the lower shell and the upper shell extends at least in one region of the boom section at an angle greater than 0 degrees to at least one section edge of the boom section.

9. A telescopic crane having at least one boom section, the boom section having a lower shell and an upper shell, wherein the lower shell and the upper shell are welded to one another, and wherein a weld seam between the lower shell and the upper shell extends at least in one region of the boom section at an angle greater than 0 degrees to at least one section edge of the boom section.

10. The boom section in accordance with claim 1, wherein the weld seam is curved and extends along the entire length of the boom section.

11. The boom section in accordance with claim 1, wherein the weld seam is curved and extends along only part of the length of the boom section.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0019] FIGS. 1, and 2 show different views of a boom section in accordance with the prior art.

[0020] FIGS. 3, and 4 show different views of the boom section in accordance with the present disclosure with a weld seam rising over the total section length.

[0021] FIGS. 5, and 6 show different views of boom sections in accordance with the present disclosure with kinked weld seams.

[0022] FIG. 7 shows different views of the boom section in accordance with the present disclosure with a freely extending weld seam.

[0023] FIG. 8 shows different views of the boom section in accordance with the present disclosure with a weld seam extending in a curved manner.

DETAILED DESCRIPTION

[0024] FIG. 1 shows a boom section of the boom of a telescopic crane known from the prior art having a lower shell 2 and an upper shell 1, wherein the lower shell 2 and the upper shell 1 are welded to one another by means of a weld seam 3 extending over the total section length. As can be recognized in FIGS. 1 and 2, the weld seam 3 extends in parallel with a section edge 4 of the boom section.

[0025] FIGS. 3 and 4 show a weld seam 3 in accordance with the present disclosure extending at an angle that can have a constant angle with the section edge 4 or with the second edges 4 over the total length of the boom section. The weld seam 3 extending at an angle can be called a fitting edge in this respect.

[0026] The welding beyond section edges 4 shown in FIGS. 3 to 7 or the welding of non-planar weld seams is possible by modern welding processes such as laser hybrid processes. The weld seam 3 can in this respect no longer extend in parallel with the section edges 4 and can instead extend at curved surfaces of the boom section and/or beyond edges. The optionally thicker lower shell 2 of the telescopic section or of the boom section can increase (e.g., the cross-sectional extent of the lower shell can increase relative to the cross-sectional extent of the upper shell) in accordance with the torque progression, such that a ratio of the lateral extent of the cross-section of the lower shell to the lateral extent of the cross-section of the upper shell at a given position along the length of the boom section is proportional to and/or varies with the compression force on the boom section and/or bending torque of the boom section at that position (e.g., when the boom section is subject to a load). A manner of construction is, however, also conceivable having an initially increasing or angled section extent or weld seam extent and having a parallel alignment of the weld seam 3 with section edges 4 of the boom section in the further extent, as is shown in FIG. 5. In the rear region of the boom section or in the right region of the boom section in FIG. 5, the further extent having the parallel alignment can be the clamping region of the boom section in which the boom section is clamped correspondingly in a different boom section or in another clamping apparatus.

[0027] Exemplary section edges 4a and 4b are identified in the rightmost cross-sectional views of FIG. 5. Section edge 4a is a longitudinally extending region of the upper shell where a bent portion of the upper shell meets a planar portion of the upper shell, and corresponds to the section edge labeled 4 in the side view shown in FIG. 5. Section edge 4b is a longitudinally extending region of the lower shell where a bent portion of the lower shell meets a planar portion of lower shell. Section edge 4a is structurally integrated in and forms part of the upper shell, and section edge 4b is structurally integrated in and forms part of the lower shell.

[0028] FIGS. 2 and 4-8 show different weld seam types in more detailed views. In this respect, the respective corresponding metal sheets of lower shell 2 and upper shell 1 are shown in unwound form in the upper region of the named Figures. In this respect, the lower shell 2 and the upper shell 1 are shown in a respective planar plan view and without the longitudinally extending section edges, that is unwound, required for completing the lower shell 2 and the upper shell 1.

[0029] Side views of the respective boom sections are shown in the middle regions of the named Figures, with additional terminations being able to be recognized at the ends of the boom sections.

[0030] Sectional views at the corresponding points of the boom sections are illustrated in the lower regions of the named Figures. It can be recognized in this respect that the lower shells 2 are as a rule thicker than the corresponding upper shells 1. Thicker can in this respect mean the sheet metal thickness of the corresponding component (e.g., the material forming the lower shell is thicker than the material forming the upper shell). The dashed vertical lines indicate the region in which the respective sections are arranged or which region of the corresponding boom section they show.

[0031] The sectional views show embodiments of the boom sections in which the lower shells 2 have a rounded lateral cross-section. All other lateral cross-sections are, however, conceivable that satisfy the demands of the corresponding telescopic crane.

[0032] The boom sections in accordance with the present disclosure can be manufactured such that a determination of which loads occur along the boom section is made in a first step. Which section thicknesses or material thicknesses are required to take up these loads along the longitudinal extent of the boom section is determined in a next step. In a next step, the geometry of lower and upper shells 2, 1 suitable for taking up the calculated loads is determined and the lower shells 2 and upper shells 1 thus defined are produced from suitable semi-finished products. The welding of the lower shell 2 and of the upper shell 1 takes place in a further step, e.g. by means of a laser hybrid process. Additional steps, e.g. for preparation or post-processing of the boom sections, or also further intermediate steps between the above-named main steps can naturally likewise be present.

[0033] FIG. 7 shows a weld seam 3 having a free extent in which regions 5 that are thicker than the remaining regions of the boom section, due to a corresponding weld seam course, can be formed by a correspondingly reinforced lower shell 2 that forms the regions 5 or that is arranged in the regions 5. The regions 5 to be thick can, for example, be portions at which force introductions into the boom section take place. Exemplary force introduction elements 9 arranged in regions 5 are shown. Force introduction elements 9 may be any structures which allow for the introduction of forces into the boom, such as welded plates or hardpoints in general.

[0034] FIG. 8 shows, in a similar manner to FIGS. 3 and 4, a weld seam 3 that extends at an angle in accordance with the present disclosure and that does not extend linearly over the total length of the boom section, but rather is at least partly curved. To better illustrate the curvature of the weld seam 3, a straight line 6 is shown and the spacing between the straight line 6 and the weld seam 3 is emphasized at specific points by two respective arrows directed against one another. The weld seams 3 of all the embodiments shown can be provided laterally at the boom sections, with a respective weld seam 3 typically being able to be provided at the left and right of the boom section (e.g., the left and right in a cross-sectional view of the boom section). The two weld seams 3 of a boom section can in this respect be symmetrical or non-symmetrical with respect to one another (e.g., a weld seam on the left side of the boom section in a cross-sectional view of the boom section may differ from a weld seam on the right side of the boom section).

[0035] An example includes a telescopic crane, which may be a mobile crane, comprising a telescopic boom which is rotatably hinged to the vehicle about an upright axis of rotation and is luffably hinged about a horizontal axis. The telescopic crane is one non-limiting embodiment of a telescopic crane which can incorporate one or more boom sections such as those described in the present disclosure.

[0036] In the example, the telescopic boom has a hinged boom section, which is hinged to the vehicle in the named manner, as well as two further telescopic boom sections which can be telescoped out of the hinged boom section. A guying of the telescopic boom is guided over a pair of guy supports. Guying-ropes lead from the free end of the guy supports to the tip of the telescopic boom, with it also being possible to guide the guy-ropes at the head of the central telescopic section, for example. The guy supports are in turn captured via guy-ropes in the region of the hinge end of the hinged section. The guy supports are movably hinged to the head of the hinged section, and indeed such that they are folded in a transport position at the hinged section, whereas they are spread apart in V shape in the manner shown in an operating position. [0037] While the example including a telescopic crane includes exactly one hinged boom section and exactly two telescopic boom sections, it will be appreciated that a telescopic crane in accordance with the present disclosure may include a different number (e.g., one, three, four, etc.) of telescopic boom sections. Further, a telescopic crane in accordance with the present disclosure may be configured without a hinged boom section.