ES2405544T3 - Profile shape for a crane arm - Google Patents

Abstract

Crane arm for a crane (4), with a longitudinal axis and with an imaginary contour line, that extend a transverse plane in relation to an axis of symmetry (s) at least approximately in mirror symmetry and linear configuration at least by sections, in which the contour line cuts the axis of symmetry (s) at a first and second intersection points (S1, S2) and narrows in the direction of the second intersection point (S2) at least in front of the last third of the distance between the first and second intersection points (S1, S2), in which the narrowing of the contour line continues to the second intersection point (S2) and ends in a rounding on the line of symmetry (s), in that the contour line between the first intersection points (S1) and a middle point (M), which is arranged equidistant to the first and second intersection points (S1, S2), presents, at least partially, a section (k1 ) at least approximately In the form of a circular arc, which is preferably configured as a quarter of a circular arc and because the midpoint of the curvature (K) of the circular arc shaped section (k1) is on or near the axis of symmetry ( s) and preferably between the first point of intersection (S1) and the midpoint (M), and in which the contour line has a linear section (g1), whose imaginary extension (g1 ') in the direction of the second point of intersection (S2) cuts the axis of symmetry (s) under an angle with acute preference (β), characterized in that a second linear section (g2) is connected in the first linear section (g2), which ends in a rounding.

Description

Profile shape for a crane arm

The invention relates to a crane arm with the features of the preamble of claim 1.

A crane arm with some features of the preamble of claim 1 is shown, for example, in Figure 13 of EP 583 552 B1.

This crane arm has the disadvantage that, especially during installation in a boom system in the upper area of the crane arm, an unfavorable introduction of force takes place. Moreover, the manufacture of such a crane arm is relatively expensive.

A crane arm with the features of the preamble of claim 1 is deduced from document DE 10 23 17 595 A1.

The purpose of the invention is to solve the described problems of the prior art.

This task is solved by means of a crane with the characteristics of claim 1.

A real crane arm presents, of course, by virtue of the thickness of the material of the components that form it both an outer contour and also an inner contour. The "imaginary contour line" refers to the

15 outer contour of the crane arm.

The center of gravity of the surface is understood in the sense of this publication as the center of gravity of the entire area included by the imaginary contour line (figure 2). The concept of "center of gravity of the surface" should therefore not be understood in relation to the surface included between the outer contour and the inner contour.

The measures according to the invention cause the crane arm to be manufactured from a single sheet. The upper part of the crane arm can be used, as a whole, for the introduction of force, particularly between the extensions of the boom during assembly in a boom system. The narrowing of the contour line upwards results in a favorable relationship between the length of the sides and the thickness of the sheet. Through the invention it is possible to use thinner sheets than in the case of the prior art.

Other advantageous embodiments are defined in the dependent claims.

The invention also relates to a boom system for a crane, in which at least one boom and / or a boom extension is configured as a crane arm according to one of claims 1 to 8. Preferably , are provided between one and twenty, preferably between five or ten extensions of the pen. It is especially preferred that more than five extensions of the pen are provided.

The invention also relates to a crane, in particular a loading crane, with a crane arm according to one of the above-mentioned embodiments or to a boom system of the type mentioned above as well as to a commercial vehicle equipped With such a crane.

Figure 1a shows a first embodiment of the imaginary contour line of a crane arm according to the invention.

Figures 1b and 1c show the construction of a line contour (figure 1b) and the corresponding sheet construction (figure 1c) of an exemplary embodiment, in which the circular arc-shaped section k1 is approximated by a line polygonal.

Figure 1c shows a pen system with three extensions of the pen according to Figure 1b.

Figure 1e shows the crane arm according to Figures 1a to 1c, in which the position of the center of surface gravity is represented.

Figure 1f shows a boom system with a boom extension, in which the arrangement of the bearing elements is shown.

Figure 1g shows a pen system with a pen extension, in which the circular arc section in the pen and the pen extension have been approximated by means of different polygons.

Figure 2 shows the crane arm according to Figures 1a to 1c and 1e, in which, as a representation of all the exemplary embodiments, that surface has been represented with a dashed line, to which the center of gravity of the surface.

Figure 3 shows a second embodiment of the contour line of an unclaimed crane arm.

Figure 4 shows the perspective view of a pen system according to Figure 1d, and

Figure 5 shows a commercial vehicle with a crane according to the invention.

It is anticipated that all figures are represented to scale to the extent that the lengths of the sections

5 individual contours as well as the angles represented are in correct relation to each other. All angle indications refer to the measurement in degrees, so that a full angle corresponds to 360 degrees. An acute angle means an angle less than ¼ full angle. An obtuse angle means an angle greater than ¼ and less than ½ full angle. An angle equal to ¼ full angle is designated as a right angle.

10 Figure 1a shows a first embodiment of the development of the imaginary line of the crane arm contour in a transverse plane of the crane arm. A transverse plane is understood in this case as a plane, which is crossed orthogonally. All crane arms according to the invention have an axis of symmetry arranged in the transverse plane, in relation to which the contour line of the crane arm extends in the transverse plane at least approximately in mirror symmetry. In the event that the crane arm is on

15 a large part or over its entire longitudinal extent the same shape of the cross section, this axis of symmetry s represents the line of intersection of the transverse plane with the plane of symmetry (middle plane) that extends along the longitudinal axis. In all embodiments, the contour line cuts the axis of symmetry s at a first and a second intersection points S1, S2. The midpoint M disposed on the axis of symmetry s equidistant from the first and second intersection points S1, S2 represents the position of half the height

20 of the crane arm in the transverse plane. Starting from the midpoint M in the direction of the intersection point S2, it is located in an area of the crane arm, which is predominantly loaded with traction in operation. The area of the guide arm, which is between the midpoint M and the first intersection point S1, is essentially loaded under pressure during operation.

The development of the contour line of the crane arm shown in Figure 1 has four sections k1, g1, 25 g2, g3, which can be differentiated from each other.

The section k1, which is arranged in the area of the maximum pressure load in operation, is configured in the form of a circular arc, since this cross-sectional shape, as it is known in itself, exhibits reduced pressure tensions and a decreased threat of buckling. It is sufficient that this section is configured, at least approximately, in the form of a circular arc in the sense that it can be approximated by

30 means of a polygon, as shown in Figures 1b and 1c. The approach of the section k1 in the form of a circular arc through a polygonal line allows a simpler fabrication through edging of the sheets that form the crane arm. But, of course, a circular arc-shaped configuration can also be made by means of a rolling process.

The circular arc-shaped section k1 can only be approximated in the form of a circular arc in the direction of

35 which may be formed, for example, by one or more elliptical sections with correspondingly reduced eccentricity. It would also be conceivable to configure a section k1 in the form of a circular arc through a juxtaposition of linear, elliptical and / or correspondingly short circular arc segments.

As shown in Figure 1, it is especially advantageous that section k1 is configured as four circular arc, that is, it extends over an angle of approximately 90 degrees. In this way, it is possible to configure the large part of the development of the contour line between the first intersection point S1 and the midpoint M in the form of a circular arc-shaped section k1. The variant shown in Figure 1 is especially preferred, in which the midpoint of the curvature K of the circular arc-shaped section k1 is in the vicinity or on the axis of symmetry and the midpoint of the curvature K of the circular arc-shaped section k1 is located between the first intersection point S1 and the midpoint M. Represented other than in the

Figure 1, the circular arc-shaped section k1 can be extended, in general, to the first intersection point S1. Therefore, in this case the entire contour line is configured in the area of the intersection point S1 and the point M as a circular arc section k1.

However, the embodiment shown in Figure 1 is especially preferred, in which tangentially the circular arc-shaped section k1 in the direction of the first intersection point S1 is

50 extends a third linear section g3, which forms an angle with the axis of symmetry! less than 90 degrees (here the angle! has approximately 72 degrees). This results in a good welding capacity of the crane arm, an improved fixing capacity for welding through the inclined sections that impinge on each other as well as the possibility of performing a longitudinal welding seam without additional preparation of the songs In general, it is a secure configuration in the process.

55 The angle is preferably less than 80 degrees. Preferably, the angle! It is higher than 70 degrees.

In the exemplary embodiment shown in Figure 1, the midpoint of the curvature K of the circular arc-shaped section k1 is directly on the axis of symmetry s between the midpoint M and the first intersection point S1. Represented in another way, the point of curvature K may also be arranged slightly offset with respect to the axis of symmetry s. However, you should always be in the area between the point

5 half M and the first intersection point S1.

In the circular arc-shaped section k1, in the direction of the second intersection point S2 tangentially to the auxiliary circle represented in Figures 1a and 1b the first linear section g1 is connected, which extends over the large part of the development the contour between the midpoint M and the second intersection point S2. Through this long linear linear configuration in the upper area of the crane arm and the narrowing of the cross section 10 resulting in this way an area is formed, which is better suited than in the state of the art for the absorption of the tensile forces that appear here as well as the support forces in the case of the arrangement in n boom system. The imaginary extension g1 ’of the linear section g1 (see Figure 1b) forms an acute angle with the axis of symmetry ∀, which is approximately 18 degrees in the embodiment shown. In general, the acute angle ∀ can also be in a range greater than 10 degrees, with

15 preference greater than 15 degrees. In this case, an upper limit of 25 degrees, respectively, is preferred to exclude a too flat development of the linear section g1.

In the exemplary embodiment according to Figure 1, in the first linear section g1 a second linear section g is connected directly, which extends to the axis of symmetry s, there ends at a edge 7 and cuts it at the second point of intersection S2 As can be recognized especially in Figure 1c, for technical reasons of

It may be desirable that the second linear section g2 (as opposed to that shown in Figure 1a) is not connected directly, but through another section preferably configured curved with the first linear section g1.

In the exemplary embodiment shown in Figure 1, the second linear section g2 forms an angle # with the axis of symmetry. Which is less than 90 degrees (in the exemplary embodiment of Figure 1, angle # has

25 approximately 85 degrees). An interval for angle # less than 70 degrees is especially preferred. However, the angle # should in this embodiment be greater than 60 degrees.

The second linear section g2, which ends in a rounded in the form of a edging 7, implies the advantage that with this in the area around the tip of the crane arm a favorable local introduction of the force is possible, as it leads to out, for example, in the support of sliding packages between individual extensions of the

30 pen Through the short length of the side a favorable relationship between the thickness of the sheet and the length of the side results, so that a deformation of the crane arm in the upper area is prevented.

However, in principle a configuration of the contour development in this area in the form of a second circular section k2 would also be possible (see Figure 3). Such configuration is not part of the invention. But this represents only a special variant of the general idea, namely that in which the

The profiled line ends in a rounding in the line of symmetry s. As an alternative to the configuration of the rounding as section k2 in the form of a circular arc, the rounding could be represented, for example, also as edging 7, as shown in Figure 1.

In general terms, in relation to all the embodiments of the crane according to the invention, it should be said that the center of gravity F of the surface formed by the profiled line in the transverse plane is

40 lies in an area between the midpoint M and the first intersection point S2, that is, below half the height of the crane arm. In this way, the concentration of the cross-section of the guide arm is moved to the downward pressure zone if possible, resulting in a smaller portion of the pressure tension.

As can be recognized from the figures, the profiled line of all embodiments shows

45 between the first intersection point S1 and the second intersection point S2 an end point E with maximum distance e from the axis of symmetry s. The distance D between the first point of intersection and the second point of intersection S2, S2 may in this case be at least twice that of the distance e. Preferably, distance D is at least two and a half times, preferably 2.75 times greater than distance e. The distance D may in each case be less than 3 times the distance e.

50 It may be provided that the distance d of the profiled line with respect to the axis of symmetry s approximately one quarter of the distance D between the first point of intersection and the second point of intersection S1, S2 starting from the second point of symmetry S2 is less than or equal to 0.8 times the maximum distance e.

In the exemplary embodiment shown in Figure 1, the end point E is between the midpoint M and the first intersection point S1 approximately at the height of the midpoint of the curvature K. In the development 55 depicted in Figure 1a , the profiled line has only a single end point E, that is, both in the direction of the first intersection point S1 and also in the direction of the second intersection point S2

the width of the crane arm is reduced starting from the end point E. In the case of the approach of the circular arc section k1 through a polygonal line, as shown in Figure 1c, naturally all the points of The polygonal section, through which the circular arc section k1 approaches in the area of the end point E, has this maximum distance e.

Starting from the auxiliary circle represented in figure 1a with the radius r, the embodiment according to figure 1 has a width of the profile b according to b ∃2r, a height of the profile D according to D ∃3r and a width of the profile above b1 according to b1 ∃r. These especially advantageous dimensions can be provided in general in crane arms according to the invention.

Figure 1e shows for the embodiment of Figure 1 the position of the center of gravity of the surface F between the midpoint M and the first intersection point S1 on the axis of symmetry s. The center of gravity of the surface F refers in this case to the surface represented with dots and strokes in Figure 2, that is, to the entire surface, which is included by the imaginary profiled line (corresponds to the outer contour).

Figure 1f shows a boom system 5 with a boom extension, in which the housing of the boom system 5 on a bearing element 1 is also shown as well as the boom extension housing on the boom on bearing elements 2. The exemplary embodiment shown is, of course, purely exemplary in relation to the number of extensions shown on the boom. The same bearing elements can be applied in boom systems 5 with a discretionary plurality of boom extensions.

In the exemplary embodiment according to Figure 1g, two crane arms are shown, in which, for example, an extension of the boom arranged in a boom is discussed. It is important that the circular arc-shaped section k1 be approximated by different polygons. The profile of the internal cross-section has less circular edging in the area of the circular arc section, which can be especially advantageous in the case of small profiles, conditioned by manufacturing.

The manufacture of a crane arm according to the invention can be carried out, for example, in such a way that the crane arm is formed by two shells, which are configured in mirror symmetry with each other and in which one of the shells corresponds in each case to one of the embodiments. The two shells may be connected to each other, for example welded, in the area of the first intersection point S1 and the second intersection point S2.

However, especially advantageously, it would be planned to manufacture the crane arm, at least along a section of its longitudinal extension of a single sheet, which is properly shaped and then closed (for example, welded) along a single line. This line can be extended, for example, in the area of the first intersection point S1 or the second intersection point S2.

The configuration of the sheets can be carried out in a known way or through edging and / or lamination as well as for example welding.

If different wall thicknesses are necessary, the outer contour should remain preferably the same and the thickness of the sheet must be applied inwards.

Figure 4 shows by way of example a pen system 5 with a pen extension arranged in a pen.

An example of a commercial vehicle 3 is shown in Figure 5, on which a crane 4 according to the invention is arranged. The crane 4 has a boom system 5 according to the invention, the individual extensions of the boom being able to move telescopically towards each other by means of thrust cylinders 6. The telescopic displacement capability e can, of course, also ensure through of other drive means. In the rear area of the commercial vehicle 3, for example, a cargo structure not shown may be arranged.

Claims (11)

1.- Crane arm for a crane (4), with a longitudinal axis and with an imaginary contour line, which extends in a transverse plane in relation to an axis of symmetry (s) at least approximately in mirror symmetry and configured linearly at least by sections, in which the contour line cuts the axis of symmetry (s) at a first and 5 a second intersection points (S1, S2) and narrows in the direction of the second intersection point (S2 ) at least in front of the last third of the distance between the first and second intersection points (S1, S2), in which the narrowing of the contour line continues to the second intersection point (S2) and ends in a rounding in the line of symmetry (s), in which the contour line between the first intersection points (S1) and a midpoint (M), which is arranged equidistant to the first and second intersection points (S1, S2) , it presents, at least partially, a section (k1) to the approximately in the form of a circular arc, which is preferably configured as a quarter of a circular arc and because the midpoint of the curvature (K) of the circular arc-shaped section (k1) is on or near the axis of symmetry (s) and preferably between the first point of intersection (S1) and the midpoint (M), and in which the contour line has a linear section (g1), whose imaginary extension (g1 ') in the direction of the second intersection point (S2) cuts the axis of symmetry (s) 15 under an angle with acute preference (∀), characterized in that in the first linear section (g1) a second linear section (g2) is connected, which ends in a rounding. 2. Crane arm according to claim 1, characterized in that the rounding is performed as edging (7). 3.-Crane arm according to claim 1 or 2, characterized in that either the second linear section (g2) 20 is connected directly in the first linear section (g1) or because the second linear section (g2) is connected through another section, preferably configured curved, with the first linear section (g1). 4. Crane arm according to claim 3, characterized in that the acute angle (∀) is greater than 10 degrees, preferably greater than 15 degrees and preferably less than 25 degrees. 5. Crane arm according to one of claims 1 to 4, characterized in that the linear section (g1) is configured as a tangential continuation of the section (k1) in the form of a circular arc. 6. Crane arm according to one of claims 1 to 5, characterized in that the circular arc-shaped section (k1) is approximated by a polygon. 7. Crane arm according to one of claims 1 to 6, characterized in that the crane arm is constituted by at least one sheet and the sheet thickness of all sections (k1, k2, g1, g2, g3 ) of the arm of 30 crane in the transverse plane is at least essentially the same size. 8. Crane arm according to one of claims 1 to 7, characterized in that the crane arm is constituted by two shells, which are configured in mirror symmetry with each other and - preferably are connected to each other in the area of the first point of intersection (S1) and the second point of intersection (S2) -. 9. Crane arm according to one of claims 1 to 7, characterized in that the crane arm is 35 constituted at least along a section of its longitudinal extension of a single sheet, which is closed along a single line, which preferably extends in the area of the first intersection point (S1) or the second point of intersection (S2). 10. A boom arm for a crane, characterized in that at least one boom and / or a boom extension are configured as a crane arm according to one of claims 1 to 9. 11. Pen system according to claim 10, characterized in that the shapes of the profiled line of the pen and the profiled lines of all extensions of the pen - if necessary, except for the degree of arc approximation circular through polygons - they are the same. 12. Crane, especially loading crane, characterized by a crane arm according to one of claims 1 to 9 or a boom system (5) according to claims 10 or 11. 13. 13. Commercial vehicle (3) with a crane (4) according to claim 12.