Boom-arm segment and method for producing a boom-arm segment

Abstract

The invention relates to a boom-arm segment for a concrete pump, wherein the boom-arm segment (30) comprises a side part (35, 36) which extends between a top chord (33) and a bottom chord (34) of the boom-arm segment (30). In the side part (35, 36), a bent portion is formed such that a first portion (42, 43) of the side part (35, 36) has a lateral offset (56) relative to a second portion (44) of the side part (35, 36). A transition portion (45, 46) forms a connection between the first portion (42, 43) and the second portion (44). The boom-arm segment (30) comprises a reinforcement part (40, 50), the material thickness of which spans the lateral offset (56) between the first portion (42, 43) and the second portion (44). The reinforcement part (40, 50) is butt-joined to the transition portion (45, 46). The invention also relates to a method for producing a boom-arm segment (30).

Description

[0001] The invention relates to a mast arm segment for a concrete pump and a method for manufacturing such a mast arm segment.

[0002] Concrete pump booms are used to guide a delivery line connected to a concrete pump so that the liquid concrete pumped by the concrete pump can be applied in an area remote from the pump. Such a concrete pump boom is typically composed of multiple boom segments, with the total length of the boom when extended and the segments folded into a compact form for easier transport when retracted.

[0003] Since concrete pumps are typically designed to deliver liquid concrete in pulses, the boom arms are subjected to significant dynamic loads. Furthermore, the boom arm segments can be folded differently depending on the distance from the pump where the liquid concrete is to be dispensed. This results in tensile and compressive loads acting on a boom arm segment in very different directions depending on the boom arm's operating state. For these reasons, the boom arm segments of a concrete pump are subjected to specific stresses during operation.

[0004] Document EP 1387012 discloses a mast arm segment according to the preamble of claim 1.

[0005] The invention is based on the objective of presenting a concrete pump mast segment and a method for manufacturing a concrete pump mast segment such that the concrete pump mast segment withstands static and dynamic loads well, is cost-effective to manufacture, and has a low weight. Starting from the aforementioned prior art, this objective is achieved by the features of the independent claims. Advantageous embodiments are specified in the dependent claims.

[0006] The invention is defined in claim 1.

[0007] The mast arm segment according to the invention comprises a side section extending between an upper chord and a lower chord of the mast arm segment. A chamfer is formed in the side section such that a first section of the side section has a lateral offset relative to a second section of the side section. The side section includes a transition section that forms a connection between the first and second sections. A reinforcing section of the mast arm segment has a material thickness that bridges the lateral offset between the first and second sections. The reinforcing section is butt-jointed to the transition section.

[0008] Reinforcing elements that rest on the side panel from the outside are known from the prior art (DE 10 2017 223 240 A1). This has the disadvantage that the mast arm segment has a greater width, which is undesirable in many cases. If a reinforcing element is to be connected to the side panel without such an increase in the width of the mast arm segment, the lateral offset between the first and second sections of the side panel must be bridged to allow the reinforcing element to be connected to both sections. The invention proposes that the lateral offset between the first and second sections be bridged by the material thickness of the reinforcing element and that the reinforcing element be butted together with the transition section.A butt joint within the meaning of the invention is a butt joint in which an end face of the transition section abuts an end face of the reinforcing part. In other words, the reinforcing part connects to the transition section longitudinally. A straight line extending longitudinally within the transition section along the mast arm segment intersects the connected end faces of the transition section and the reinforcing part.

[0009] The invention recognizes that such a combination of a reinforcing element and a side element effectively absorbs the static and dynamic forces occurring in the mast arm segment. The chamfer in the side element, extending longitudinally along the mast arm segment, increases its resistance to buckling deformation, allowing for a thinner material thickness compared to a flat side element without a chamfer. The resulting weight reduction is particularly important for components of a concrete pump located far from the slewing mechanism, as the pump can tip over if the load moment becomes too great. Furthermore, the lower components can be made less robust, since they no longer have to support the additional weight of the now lighter outer components.The reinforcement element can connect longitudinally to the transition section of the mast arm segment and form a section of the mast arm segment designed to transmit greater forces. For example, the reinforcement element can incorporate a hinged connection for linking to an adjacent mast arm segment or a receptacle for a hydraulic cylinder.

[0010] The material of the side section can be dimensioned to withstand the normal loads occurring along the length of the mast arm. In areas of the mast arm where increased loads occur, such as at joint mounts or mounts for hydraulic cylinders, the mast arm segment is reinforced with a reinforcing element whose material thickness is greater than that of the side section. The invention proposes selecting the material thickness of the reinforcing element to be large enough to bridge the lateral offset between the first and second sections of the side section. In this way, the reinforcing element can be butted together with the transition section, i.e., end-to-end.Furthermore, it is now possible to create a direct connection between the reinforcement section and the side panel in areas adjacent to the transition section of the first and second sections of the side panel. This results in a smooth transition between the reinforced force application area and the bending beam.

[0011] The connection between the side panel and the reinforcement panel can be a welded joint. The weld can be butt-welded along the entire length of the joint between the reinforcement panel and the side panel, so that an end face of the reinforcement panel is welded to an end face of the side panel. It is also possible for the weld to include butt-welded and overlapping welded sections. The butt-welded sections of the weld can include the connection to the transition section of the side panel as well as other sections.

[0012] The weld joint may include sections where the areas of the side member and the reinforcement member adjacent to the weld joint lie in parallel planes. This can apply to all sections of the weld joint that do not adjoin the transition section of the side member. In particular, an overlap between the side member and the reinforcement member may be provided in areas where the reinforcement member and the side member are not butted together. Conversely, the joint may be free of an overlap where the reinforcement member and the side member are butted together.

[0013] In one embodiment, the reinforcing element is butt-jointed to the first section of the side panel and overlaps with the second section of the side panel. The first section can form an edge section of the side panel, adjacent to the top or bottom chord of the mast arm segment. The second section can form a central section of the side panel, spaced apart from the top and bottom chords. The reinforcing element can be connected to the second section of the side panel by a weld extending along a portion of a circumferential edge of the reinforcing element. The material thickness of the reinforcing element can be dimensioned such that it does not project outwards beyond the first section of the side panel. It is desirable that the reinforcing element does not increase the width of the mast arm segment compared to the contour defined by the side panels.In one embodiment, the side surface of the reinforcement element is flush with the first section of the side panel. The invention also encompasses embodiments in which the first section of the side panel projects further outwards in the lateral direction than the reinforcement element. It is also possible for the outer surface of the reinforcement element to be flush with the inner surface of the first section. This allows for an overlap on the inner surface of the reinforcement element.

[0014] The side section can be designed to include an upper edge section adjacent to the top chord and a lower edge section adjacent to the bottom chord. The reinforcing element can be dimensioned to butt-join both the transition section between the central section and the upper edge section, and the transition section between the central section and the lower edge section. Additionally, the reinforcing element can butt-join both the upper and lower edge sections. The reinforcing element can overlap with the central section. The above and below specifications refer to the state of the mast arm segment as shown in the drawings and do not imply any restriction regarding the subsequent assembly position of the mast arm segment.In particular, mounting positions are possible that are rotated by 90° or 180° compared to the state shown in the figures.

[0015] An upper end of the reinforcement element can terminate in the upper edge section, so that the reinforcement element does not project upwards beyond the contour defined by the top chord. A lower end of the reinforcement element can project beyond the lower edge section. This is particularly advantageous when the reinforcement element forms a hinge receptacle for the mast arm segment, connecting the mast arm segment to an adjacent mast arm segment or the base of the mast arm. The reinforcement element can include a receptacle for a hinge pin. The hinge pin can be positioned below the bottom chord.

[0016] The lateral offset between the first and second sections of the side panel can be created by bending the side panel multiple times. Between the first section and the transition section, the side panel can be bent in one direction. Between the transition section and the second section, the side panel can be bent in the opposite direction. The bend angle of the two edges can be chosen such that the first section of the side panel lies in a plane parallel to the second section. The transition section can extend in a plane that intersects the plane of the first side panel at an angle between 10° and 80°, preferably at an angle between 15° and 30°.If the side part has an upper edge section and a lower edge section, the transition between the central section and the upper edge section, as well as the transition between the central section and the lower edge section, can be formed by two such edge combinations.

[0017] The first section, the transition section, and the second section of the side panel can be elements of a shell component, in which the shell component comprises a surface section of the top or bottom chord. The shell component can consist of a metal sheet that is bent between the surface section of the top or bottom chord and the edge section of the side panel. An edge region of the top or bottom chord can form an angle between 70° and 100°, preferably an angle between 80° and 90°, with the edge section of the side panel.

[0018] The mast arm segment can comprise a box section with a top chord, a bottom chord, and two side sections arranged between the top and bottom chords. The box section can be composed of half-shells. A first half-shell can comprise the top chord as well as an upper edge section and an upper transition section of each of the opposing side sections. A second half-shell can comprise the bottom chord as well as a lower edge section and a lower transition section of each of the opposing side sections. Each of the side sections can be chamfered such that the central sections have a lateral offset relative to the edge sections. The chamfer can be designed such that the distance between the central sections of the opposing side sections is smaller than the distance between the edge sections of the opposing side sections.

[0019] The top chord and / or the bottom chord can be made of flat sheets. To further increase the stability of the mast arm segment, multiple longitudinally oriented edges can be incorporated into the top chord and / or the bottom chord. These edges can all be bent in the same direction, giving the top / bottom chord a curved profile in cross-section. Alternatively, edges bent in opposite directions are possible, creating one or more corrugations in the top chord and / or bottom chord.

[0020] The side sections of the box-shaped profile can be arranged in a plane parallel to gravity. In a section of the box-shaped profile, viewed perpendicular to the longitudinal axis of the mast arm segment, the side sections and / or the flange surfaces can be aligned parallel to each other.

[0021] Particularly when the box profile is composed of two half-shells, but also when there is a different number of sub-profiles distributed around the circumference of the box profile, it may be possible to create a connection between two profile parts arranged within the side panel. In one embodiment, the connection is not arranged in one of the edge sections of the side panel, but in a central section of the side panel that is angled relative to the edge section.

[0022] The connection within the side section between a first and a second profile section of the box section can be a butt joint or an overlap. The connection can be made with a weld extending along the end edge of one of the profile sections. The end edge of the other profile section can be chamfered relative to the central section, so that the end edge acts as an additional buckling stiffener. This buckling stiffener can be oriented inwards relative to the box section.

[0023] The reinforcing element can include an end section that tapers within the side section. The end section can taper into the side section. The end section can overlap the side section. The tip of the end section can terminate in the central section of the side section. The tip is defined as the outermost point of the end section, regardless of whether the end section tapers to a point or has another shape, such as a rounded edge. The tip of the end section can be positioned at a distance from a weld joint connecting profile sections of the box section. In particular, the tip of the end section can be located near the neutral axis of the mast arm segment, meaning that the distance between the tip of the end section and the nearest flange is at least twice, preferably three times, and more preferably five times greater than the distance between the tip and the neutral axis.The end section can be connected to the side panel by a circumferential weld. To avoid stress concentrations, the weld can extend beyond the end of the section into the side panel. Another measure to avoid stress concentrations is to machine the reinforcement section, for example by milling, to reduce its material thickness in a specific area. This is particularly relevant in areas where the reinforcement section overlaps the side panel. It is also possible to reduce the material thickness in areas where the reinforcement section is subject to less stress, in order to reduce weight.

[0024] The box section can taper from proximal to distal. The taper can refer to the vertical and / or the horizontal plane. The length over which the box section tapers can be at least 30%, preferably at least 50%, and more preferably at least 70% of the length of the mast arm segment. Proximal refers to an end of the mast arm segment that, in the extended state of the mast arm, is closer to the base (i.e., the truck) from which the mast arm is suspended. Conversely, the distal end of the mast arm segment, in the extended state, is closer to the free end of the mast arm.

[0025] The reinforcement element can form a proximal pivot point for the mast arm segment. The reinforcement element can incorporate a receptacle for a pivot pin. A pivot lever, to which a hydraulic cylinder can be connected, can be attached to the reinforcement element. The hydraulic cylinder's function is to pivot the mast arm segment relative to an adjacent structure, particularly another mast arm segment. The pivot lever can be connected to the reinforcement element via a pivot joint.

[0026] It is also possible that the reinforcement part is designed as a receptacle for a hydraulic cylinder. In particular, the reinforcement part can form a receptacle for a pivot pin, via which a hydraulic cylinder can be pivotally connected to the reinforcement part.

[0027] In one embodiment, the mast arm segment comprises a first reinforcing element configured as a hinged receptacle and a second reinforcing element configured as a receptacle for a hydraulic cylinder. Both reinforcing elements can have the aforementioned features and be connected to the side sections in the manner described. The hinged receptacle can form one end of the mast arm segment. The receptacle for the hydraulic cylinder can be spaced apart from the ends of the mast arm segment. In particular, the distance between the receptacle and the nearest end of the mast arm can be at least 5%, preferably at least 10%, of the length of the mast arm segment. The distance between the first reinforcing element and the second reinforcing element can be at least 10%, preferably at least 30%, of the length of the mast arm segment.

[0028] The reinforcing element can extend across the width of the mast arm segment and be connected to one of the side pieces on both sides of the mast arm segment as described. In particular, the reinforcing element can be designed so that it does not project laterally beyond the upper edges of the side pieces on either side. This prevents the mast arm segment from increasing in width due to the reinforcing element. The reinforcing element can be a bent sheet of metal. It is also possible for the reinforcing element to be manufactured in other ways, for example, as a casting, a forging, or by 3D printing. The side piece can be made of sheet metal.

[0029] The mast arm segment can include a mounting receptacle for a conveyor pipe support. The mounting receptacle can extend transversely through the mast arm segment, forming a cross-connection between the opposing side sections of the mast arm segment. For example, the mounting receptacle can be welded to each of the side sections. The mounting receptacle can extend between the central sections of the opposing side sections. In this way, the mounting receptacle can provide additional protection against the side sections of the mast arm segment deflecting laterally under load. The connection to the side sections allows the forces exerted by the attached elements to be effectively transferred into the side sections.

[0030] On one side of the mast arm segment, the mounting bracket can project beyond the side panel. On this side, the mounting bracket can be designed to accommodate a holder for the conveying line. For example, blind holes for a screw connection can be provided. Alternatively, the holder can be welded to the mounting bracket. In one embodiment, the mast arm segment includes a holder for a conveying line connected to the mounting bracket and / or a conveying line connected to the mounting bracket. Furthermore, hydraulic lines can be connected to the mast arm segment, enabling, for example, the operation of hydraulic devices for folding and unfolding the mast arm.

[0031] The mast arm segment can comprise a plurality of such mounting receptacles, in particular at least two, preferably at least three, and more preferably at least four. The mounting receptacles can be substantially evenly distributed along the length of the mast arm segment. One or more of the mounting receptacles can be connected to a reinforcing element.

[0032] The application also discloses a concrete pump mast arm with a plurality of mast arm segments. A pivot joint is formed between each pair of adjacent mast arm segments. The axis of the pivot joint can be oriented such that it extends through both side parts of the mast arm segment, the two side parts preferably being intersected at right angles or forming an angle of less than 10°, preferably less than 5°, with this direction. The flange surfaces can extend parallel to the pivot axis.

[0033] The joint can comprise a first articulated lever pivotally attached to a first mast arm segment. The joint can also comprise a second articulated lever pivotally attached to the second mast arm segment and pivotally attached to the first articulated lever. A hydraulic cylinder can extend from the first mast arm segment to the first articulated lever, such that a lifting motion of the hydraulic cylinder is translated into a pivoting motion between the mast arm segments. Viewed from the first mast arm segment, the hydraulic cylinder is preferably attached to the first articulated lever beyond the second articulated lever.

[0034] The concrete pump boom can include a delivery line for a viscous material, particularly fresh concrete, extending along the boom. Each boom segment can be associated with a segment of the delivery line. Adjacent segments of the delivery line can be connected to each other via a joint, the axis of which is preferably coaxial with the joint connecting the associated boom segments. The individual segment of the delivery line can be designed as a rigid pipe.

[0035] The invention further relates to a method for manufacturing a mast arm segment for a concrete pump, according to claim 1, wherein the mast arm segment comprises a side section extending between an upper chord and a lower chord of the mast arm segment. A chamfer is formed in the side section such that a first section of the side section has a lateral offset relative to a second section of the side section. A transition section forms a connection between the first section and the second section. A reinforcing element, the material thickness of which bridges the lateral offset between the first section and the second section, is butted together with the transition section.

[0036] The method can be further developed with additional features, which are described in connection with the mast arm segment according to the invention. The mast arm segment can be further developed with additional features, which are described in connection with the method according to the invention.

[0037] The invention is described below by way of example with reference to advantageous embodiments in the accompanying drawings. They show: Fig. 1: A concrete pump truck with a mast arm in the folded position; Fig. 2: The concrete pump truck made of Fig. 1 with unfolded mast arm; Fig. 3: a mast arm segment according to the invention; Fig. 4: a joint between two mast arm segments; Fig. 5: the proximal end of the mast arm segment made of Fig. 3 in enlarged view; Fig. 6: a section of the mast arm segment made of Fig. 3 in enlarged view; Fig. 7: the distal end of the mast arm segment made of Fig. 3 in enlarged view; Fig. 8: a mounting bracket of the mast arm segment made of Fig. 3 in enlarged view; Fig. 9: the mounting bracket made of Fig. 8 from a different perspective; Fig. 10: the proximal end of the mast arm segment from Fig. 5 in perspective view; Fig. 11: the distal end of the mast arm segment made of Fig. 7 in perspective view; Fig. 12: a cross-section along line AA in Fig. 5 .

[0038] One in Fig. 1 The truck 14 shown is equipped with a concrete pump 15, which pumps liquid concrete from a pre-filling tank 16 through a delivery line 17. The delivery line 17 extends along a mast arm 18, which is rotatably mounted on a slewing ring 19. The mast arm 18 comprises three mast arm segments 20, 21, 22, which are articulated together. By pivoting the mast arm segments 20, 21, 22 relative to each other via the joints, the mast arm 18 can be moved between a folded state ( Fig. 1 ) and an unfolded state ( Fig. 2 ) change. The delivery line 17 extends beyond the distal end of the third mast arm segment 22, so that the liquid concrete can be applied in an area remote from the concrete pump 15.

[0039] Depending on the swivel position of the mast arm, the loads act on the mast arm segments 20, 21, and 22 in very different directions. Furthermore, the mast arm is subjected to a high dynamic load due to the intermittent delivery of the liquid concrete.

[0040] The pivot joints between the mast arm segments 20, 21, 22 are designed to allow a large pivot angle. In the folded state, the mast arm segments 20, 21, 22 lie essentially parallel to each other and form a small angle between them. In the unfolded state according to Fig. 2 The mast arm segments 20, 21, 22 extend approximately in line with each other.

[0041] The joint design is in Fig. 4 This is illustrated using the example of the pivot joint between the first mast arm segment 20 and the second mast arm segment 21. The joint axis is formed by a joint pin 23, through which a proximal end of the mast arm segment 21 is connected to a distal end of the mast arm segment 20. Adjacent to the joint pin 23, a first joint lever 24 is attached to the first mast arm segment 20. Adjacent to the joint pin 23, a second joint lever 25 is attached to the second mast arm segment 21. The two joint levers are pivotally connected to each other at 26. A hydraulic cylinder 27 extends from a receptacle 28 on the first mast arm segment 20 to the outer end of the first articulated lever 24. Via the articulated levers 24, 25, a lifting movement of the hydraulic cylinder 27 is translated into a pivoting movement between the mast arm segments 20, 21.

[0042] One in Fig. 3 The mast arm segment 30 shown according to the invention extends from a proximal end 31 to a distal end 32. The mast arm segment 30 is designed as a box-shaped profile with an upper chord 33, a lower chord 34, and two side sections 35, 36. The box-shaped profile of the mast arm segment tapers continuously from the proximal end 31 to the receptacle 28 for the hydraulic cylinder. Thus, the two side sections 35, 36, as well as the upper chord 33 and the lower chord 34, approach each other with increasing distance from the proximal end 31.

[0043] Near the proximal end 31, the mast arm segment 30 is reinforced with a first reinforcing element 40, which forms a proximal joint receptacle 57 of the mast arm segment 30. Extending from the first reinforcing element 40, the box-shaped profile is formed towards the distal end 32. The box-shaped profile is composed of an upper half-shell 41 and a lower half-shell 47, each formed as bent sheet metal.

[0044] According to the cross-sectional view in Fig. 12 The two side sections 35, 36 each comprise an upper edge section 42, which adjoins the upper chord 33, and a lower edge section 43, which adjoins the lower chord 34. The upper edge section 42 and the lower edge section 43 lie in the same plane. A central section 44 is arranged between the edge sections 42, 43, which has a lateral offset 56 relative to the edge sections 42, 43. The side parts 35, 36 are bent inwards, so that the central sections 44 of the two side parts 35, 36 are closer together than the edge sections 42, 43 of the side parts 35, 36. Transition sections 45, 46 are formed between the central section 44 and the edge sections 42, 43, each forming an angle of approximately 30° with the plane of the edge sections 42, 43 and the parallel plane of the central sections 44, respectively.

[0045] The upper half-shell 41 comprises the top flange, the upper edge sections 42, the upper transition sections 45, and the upper part of the central sections 44 of both side members 35 and 36. The lower half-shell 47 comprises the bottom flange 34, the lower edge sections 33, the lower transition sections 46, and the lower part of the central section 44 of both side members 35 and 36. The upper end of the lower half-shell 47 overlaps the lower end of the upper half-shell 41. A weld is formed at the lower end of the upper half-shell 47, connecting the two half-shells 41 and 47. The lower half-shell 47 has its end edge 55 bent inwards, thus forming a buckling stiffener for the box section.

[0046] The first reinforcement part 40 has a greater material thickness than the box profile made of the half-shells 41, 47, see Fig. 12 The outer surface of the first reinforcement section 40 coincides with the outer surface of the upper edge sections 42. The inner surface of the first reinforcement section 40 coincides with the outer surface of the central sections 44. The box profile alternates between the outer and inner surfaces of the first reinforcement section 40 at the transition sections 45 and 46.

[0047] The transition sections 45, 46 and the edge sections 42, 43 are butt-welded to the first reinforcement section 40. The central sections 44 overlap the first reinforcement section 40. The connection between the first reinforcement section 40 and the central sections 44 is formed by a circumferential weld around the first reinforcement section 40.

[0048] In Fig. 12 A straight line extending longitudinally along the side panel is essentially perpendicular to the plane of the drawing. In the area of ​​an upper edge section 42, where the connection to the reinforcing part 40 is butted, a straight line extending inside the upper edge section 42 intersects an end face of the upper edge section 42 and an end face of the reinforcing part 40 at the butt joint. Similarly, in the area of ​​the transition sections 45, 46, and in the area of ​​the lower edge sections 43, such a straight line intersects the corresponding end faces. In contrast, the connection to the central sections 44 is overlapping, so that the inside of the reinforcing part 40 is flush with the outside of the central sections 44.A straight line extending longitudinally within the central section 44 does not intersect the end face of the reinforcement part 40, but extends at a distance to the inside of the reinforcement part 40.

[0049] According to Fig. 5 , 10 The first reinforcement section 40 has a joint bore 37. This joint bore accommodates the joint bolt 23, which connects the mast arm segment 30 to an adjacent mast arm segment. Next to the joint bore 37, a stud bolt 38 is arranged, to which the joint lever 25 is attached. Similarly, near its distal end, the mast arm segment 30 includes another joint bore 37 and another stud bolt 38, to which a joint lever 24 can be attached.

[0050] The mast arm segment 30 includes a second reinforcement part 50, which forms the receptacle 28 for the hydraulic cylinder. The second reinforcement part 50 has the same material thickness as the first reinforcement part 40 and fits into the contour of the upper half-shell 41 in the same way. The second reinforcement part 50 thus overlaps the central sections 44 of the side parts 35, 36 and is connected to the upper half-shell 41 there by a circumferential weld. The upper transition section 45 and the upper edge section 42 are butt-welded to the second reinforcement part 50.

[0051] The Fig. 7 and 11The distal joint receptacle 51 shown comprises a reinforcing plate 52, which is doubled onto the sheet of the box section. The connection between the reinforcing plate 52 and the box section is formed by a circumferential weld that extends over the circumference of the reinforcing plate 52. The joint receptacle 51 includes a joint bore 37, which accommodates the joint bolt 23 for connection to an adjacent mast arm segment. A stud bolt 38 is arranged next to the joint bore 37, to which the joint lever 25 is connected.

[0052] The mast arm segment includes, according to Fig. 3 A plurality of mounting receptacles 53 for attaching brackets (not shown) for the conveying line 17. A first mounting receptacle 53 is connected to the first reinforcement part 40. Two further mounting receptacles 53 are arranged in the side parts 35, 36 of the box profile. A fourth mounting receptacle 53 is arranged near the distal joint receptacle 51.

[0053] According to the Fig. 8 und 9 The mounting receptacle 53 forms a transverse connection 54 between the first side section 35 and the second side section 36. The transverse connection 54 is formed by a pipe section that is welded to the central sections 44 of both side sections 35, 36. By holding the side sections 35, 36 at a fixed distance from each other by the pipe section 54, the mounting receptacles 53 counteract buckling deformation of the mast arm segment 30.

[0054] On the side of the first side panel 35, the pipe section 54 ends as a stub pipe that projects slightly beyond the central section 44 of the side panel 35. On the side of the second side panel 36, the mounting receptacle 53 is provided with four threaded holes to which the holder for the delivery pipe can be screwed.

Claims

1. Boom-arm segment for a concrete pump, wherein the boom-arm segment (30) comprises a lateral part (35, 36) which extends between an upper chord (33) and a lower chord (34) of the boom-arm segment (30), and wherein configured in the lateral part (35, 36) is a bent edge extending in a longitudinal direction of the boom-arm segment so that a first portion (42, 43) of the lateral part (35, 36) has a lateral offset (56) relative to a second portion (44) of the lateral part (35, 36), and having a transition portion (45, 46) which forms a connection between the first portion (42, 43) and the second portion (44), wherein the boom-arm segment (30) has a reinforcement part (40, 50), the material thickness of the latter bridging the lateral offset (56) between the first portion (42, 43) and the second portion (44), characterized in that the reinforcement part (40, 50) and the transition portion (45, 46) are connected by way of a butt joint so that an end face of the transition portion (45, 46) bears on an end face of the reinforcement part (40, 50) and so that the reinforcement part (40, 50) adjoins the transition portion (45, 46) in the longitudinal direction.

2. Boom-arm segment according to Claim 1, characterized in that the connection between the reinforcement part (40, 50) and the lateral part (35, 36) is designed as a welded connection.

3. Boom-arm segment according to Claim 1 or 2, characterized in that the reinforcement part (40, 50) and the first portion (42, 43) of the lateral part (35, 36) are connected by a butt joint.

4. Boom-arm segment according to one of Claims 1 to 3, characterized in that the reinforcement part (40, 50) overlaps the second portion (44) of the lateral part (35, 36).

5. Boom-arm segment according to Claim 4, characterized in that the reinforcement part (40, 50) is connected to the second portion (44) of the lateral part (35, 36) by a weld seam which extends along a portion of an encircling edge (58) of the reinforcement part (40, 50).

6. Boom-arm segment according to one of Claims 1 to 5, characterized in that the first portion (42, 43) forms a peripheral portion of the lateral part (35, 36), which peripheral portion is contiguous to the upper chord (33) or the lower chord (34) of the lateral part (35, 36).

7. Boom-arm segment according to one of Claims 1 to 6, characterized in that the second portion (34) forms a central portion (44) of the lateral part (35, 36), which central portion (44) is spaced apart from the upper chord (33) and the lower chord (34).

8. Boom-arm segment according to Claim 6 or 7, characterized in that the lateral part (35, 36) comprises an upper peripheral portion (42) and a lower peripheral portion (43), and in that the reinforcement part (40) is welded to the upper peripheral portion (42) and to the lower peripheral portion (43).

9. Boom-arm segment according to one of Claims 1 to 8, characterized in that the first portion (42, 43), the transition portion (44), and the second portion (45, 46) of the lateral part are elements of a shell component (41, 47) in which the shell component (41, 47) comprises an areal portion of the upper chord (33) or of the lower chord (34).

10. Boom-arm segment according to one of Claims 1 to 9, characterized in that the boom-arm segment (30) comprises a box section with an upper chord (33), a lower chord (34), and two lateral parts (35, 36) disposed between the upper chord (33) and the lower chord (34), and in that the box section is assembled from half-shells (41, 47), wherein a first half-shell (41) comprises the upper chord (33) and in each case one upper peripheral portion (42) and in each case one upper transition portion (45) of the mutually opposite lateral parts (35, 36), and wherein a second half-shell (47) comprises the lower chord (34) and in each case one lower peripheral portion (43) and in each case one lower transition portion (46) of the mutually opposite lateral parts (36).

11. Boom-arm segment according to Claim 10, characterized in that the first half-shell (41) and the second half-shell (47) are connected to one another in the central portion of the lateral part.

12. Boom-arm segment according to Claim 10 or 11, characterized in that an end edge (55) of the second half-shell (47) is edge-bent in relation to the central portion (44) so as to form a buckling strength for the box section.

13. Boom-arm segment according to one of Claims 10 to 12, characterized by a fastening receptacle (53) for a holder of a conveying line (17), wherein the fastening receptacle forms a transverse connection (54) between the mutually opposite lateral parts (35, 36) of the boom-arm segment (30).

14. Boom-arm segment according to one of Claims 1 to 13, characterized by a first reinforcement part (40) which is configured as a joint receptacle (57), and by a second reinforcement part (50) which is designed as a receptacle (28) for a hydraulic cylinder.

15. Method for producing a boom-arm segment for a concrete pump, wherein the boom-arm segment (30) comprises a lateral part (35, 36) which extends between an upper chord (33) and a lower chord (34) of the boom-arm segment (30), and wherein configured in the lateral part (35, 36) is a bent edge extending in a longitudinal direction of the boom-arm segment so that a first portion (42, 43) of the lateral part (35, 36) has a lateral offset (56) relative to a second portion (44) of the lateral part (35, 36), and having a transition portion (45, 46) which forms a connection between the first portion (42, 43) and the second portion (44), wherein a reinforcement part (40, 50), the material thickness of the latter bridging the lateral offset (56) between the first portion (42, 43) and the second portion (44), is connected to the transition portion (45, 46) by way of a butt joint so that an end face of the transition portion (45, 46) bears on an end face of the reinforcement part (40, 50) and so that the reinforcement part (40, 50) adjoins the transition portion (45, 46) in the longitudinal direction.

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