WO2022180160A1

WO2022180160A1 - Boom-arm segment and method for producing a boom-arm segment

Info

Publication number: WO2022180160A1
Application number: PCT/EP2022/054641
Authority: WO
Inventors: Andreas Benz; Ansgar MÜLLER; Benjamin RAU
Original assignee: Putzmeister Engineering Gmbh
Priority date: 2021-02-26
Filing date: 2022-02-24
Publication date: 2022-09-01
Also published as: EP4298297A1; US20240133191A1; DE102021104701A1; CN116917589A; KR20230150291A

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

Mast arm segment and method of making one

mast arm segment

The invention relates to a boom arm segment for a concrete pump and a method for producing such a boom arm segment.

Concrete pump boom arms are used to route a delivery line connected to a concrete pump in such a way that the liquid concrete delivered by the concrete pump can be discharged in an area away from the concrete pump. Such a concrete pump mast arm is usually composed of a plurality of mast arm segments, with the sum of the mast arm segments making up the length of the mast arm in an unfolded state, and with the mast arm segments being folded together in a compact state in a folded state are to facilitate transport.

Since concrete pumps are normally set up to pump the liquid concrete in spurts, the boom arms are subject to considerable dynamic loads. In addition, the boom arm segments can be folded differently when the concrete pump is in operation, depending on the distance at which the liquid concrete is to be discharged from the concrete pump. This means that the tensile and compressive loads on a mast arm segment act in very different directions, depending on the operating state of the mast arm. For these reasons, boom arm segments of a concrete pump are exposed to special loads during operation.

The object of the invention is to present a concrete pump boom arm segment and a method for producing a concrete pump boom arm segment, so that the concrete pump boom starm segment withstands the static and dynamic loads well, is inexpensive to manufacture and has a low weight. Based on the prior art, the object is achieved with the features of the independent claims. Advantageous embodiments are specified in the claims at under.

The mast arm segment according to the invention comprises a side part which extends between an upper chord and a lower chord of the mast arm segment. A fold is formed in the side part, so that a first section of the side part has a lateral offset relative to a second section of the side part. The side piece includes a transition section that forms a connection between the first section and the second section. A reinforcement part of the mast arm segment has a material thickness that bridges the lateral offset between the first section and the second section. The reinforcement part is butt-connected to the transition section.

Reinforcement elements that rest on the side part from the outside are known from the prior art, DE 102017 223 240 A1. This brings with it the disadvantage that the mast arm segment has a greater extent in the width dimension, which is undesirable in many cases. If a reinforcement part is to be connected to the side part without such an increase in the width of the mast arm segment, the lateral offset between the first section and the second section of the side part must be bridged in order to allow the reinforcement part to be connected to both the first section and also to allow the second section of the side part. With the invention it is proposed that the lateral offset between the first section and the second section is bridged by the material thickness of the reinforcement part and that the reinforcement part is butt-connected to the transition section. A joint within the meaning of the invention is a butt joint in which an end face of the transition section bears against an end face of the reinforcing part. In other words, the reinforcement part adjoins the transition section in the longitudinal direction. A straight line extending within the transition section in the longitudinal direction of the mast arm segment intersects the connected end faces of the transition section and the reinforcement part.

The invention has recognized that with such a combination of a reinforcement part and a side part, the static and dynamic forces occurring in the mast arm segment can be well absorbed. With the bevel in the side part, which extends in the longitudinal direction of the mast arm segment, the resistance to buckling is increased, so that a lower material thickness can be used for the side part compared to a flat side part without a bevel. The lower weight achieved in this way is particularly important for the parts of a concrete pump that are far away from the slewing gear, since the concrete pump can tip over if the load moment becomes too great. In addition, the underlying components can then be made less strong, since they do not have to carry the additional weight of the now lighter external parts. The reinforcement part can adjoin the transition section of the mast arm segment in the longitudinal direction and form an area of the mast arm segment that is designed for introducing greater forces into the mast arm segment. For example, an articulated connection for a connection to a neighboring boom arm segment or a receptacle for a hydraulic cylinder can be formed in the ampli effect part The side panel material can be dimensioned to withstand the normal loads encountered along the length of the mast arm. In areas of the mast arm where higher loads occur, such as joint mounts or recordings for hydraulic cylinders, the mast arm segment is reinforced with a reinforcement part whose material strength is greater than the material thickness of the side part. The invention proposes that the material thickness of the reinforcement part be chosen so large that the reinforcement part bridges the lateral offset between the first section and the second section of the side part. In this way, the reinforcement part can be connected to the transition section in abutting manner, ie end face to end face. It is also possible to create a direct connection between the reinforcement part and the side part in areas of the first and second section of the side part that adjoin the transition part. This results in a harmonious transition between the reinforced force application area and the bending beam.

The connection between the side part and the reinforcement part can be designed as a welded joint. The welded connection may be formed butt over the entire length of the connection between the reinforcement part and the side part, so that an end face of the reinforcement part is welded to an end face of the side part. It is also possible for the welded joint to include butt-welded and lap-welded sections. The butt welded portions of the weld joint may include the connection to the transition portion of the side panel as well as other portions.

The welded connection can include sections in which the areas of the side part adjoining the welded connection and of the reinforcement part lie in mutually parallel planes. This can apply to all sections of the welded joint that do not border on the transition section of the side part. In particular, an overlap between the side part and the reinforcement part can be provided in areas in which the ampli effect part and the side part are not connected to each other in abutting manner. Conversely, the connection may be free of overlap where the reinforcement piece and the side piece are butt joined together.

In one embodiment, the reinforcement member is butt-joined to the first portion of the side panel and lap-joined to the second portion of the side panel. The first section can form an edge section of the side part, which borders on the upper chord or the lower chord of the mast arm segment. The second section can form a central section of the side part, which is spaced apart from the upper chord and the lower chord. The reinforcement panel may be connected to the second portion of the side panel by a weld extending along a portion of a peripheral edge of the reinforcement panel. The material thickness of the reinforcement part can be dimensioned such that the reinforcement part does not protrude outward beyond the first section of the side part. It is desirable that no increase in the width of the mast arm segment is caused by the reinforcement part compared to the contour spanned by the side parts. In one embodiment, the side surface of the reinforcement part terminates flush with the first section of the side part. The invention also includes embodiments in which the first section of the side part projects further outwards in the lateral direction than the reinforcement part. It is also possible that the outside of the reinforcement part is flush with the inside of the first section. closes. This opens up the possibility of an overlap on the inside of the reinforcement part.

The side panel may be configured to include an upper edge portion that adjoins the upper chord and a lower edge portion that abuts the lower chord. The reinforcing member may be dimensioned to butt connect to both the transition portion between the central portion and the upper edge portion and the transition portion between the central portion and the lower edge portion. In addition, the reinforcing member may be butt-joined to both the upper edge portion and the lower edge portion. The reinforcement part can be in an overlapping connection with the central section. The information above and below refers to the condition of the mast arm segment shown in the drawings and does not mean any restriction with regard to the subsequent assembly position of the mast arm segment. In particular, mounting positions are possible that are rotated by 90° or by 180° compared to the state shown in the figures.

An upper end of the reinforcement part can end in the upper edge section, so that the reinforcement part does not protrude upwards beyond the contour spanned by the upper chord. A lower end of the reinforcement member may protrude beyond the lower edge portion. This is particularly useful when the reinforcement part forms a joint receptacle of the mast arm segment, via which the mast arm segment is connected to a neighboring mast arm segment or a base of the mast arm. The reinforcement part can include a receptacle for a hinge pin. The hinge pin can be arranged in a position below the lower chord. The lateral offset between the first section and the second section of the side part can be produced by folding the side part several times. The side part can be bent in one direction between the first section and the transition section. The side part can be bent in the opposite direction between the transition section and the second section. The bending angle of the two edges can be selected such that the first section of the side part lies in a plane which is parallel to the second section of the side part. The transition section can extend in a plane which intersects the plane of the first side part 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 and the transition between the central section and the lower edge section can be formed by two such edge combinations.

The first section, the transition section and the second section of the side part can be an element of a shell component in which the shell component comprises a surface section of the upper chord or the lower chord. The shell component can consist of a metal sheet which is folded between the surface section of the upper chord or lower chord and the edge section of the side part. An edge area of the upper chord or lower chord can enclose an angle of between 70° and 100°, preferably an angle of between 80° and 90°, with the edge section of the side part.

The mast arm segment can comprise a box profile with an upper chord, a lower chord and two side parts arranged between the upper chord and the lower chord. The box profile can be composed of half-shells. A first half shell can comprise the upper chord as well as an upper edge section and an upper transition section of the opposite side parts. A second half-shell can include the lower chord as well as a lower edge section and a lower transition section of the opposite side parts. Each of the side parts can be provided with a fold so that the central sections have a lateral offset relative to the edge sections. The fold may be designed so that the distance between the central portions of the opposite side parts is smaller than the distance between the edge portions of the opposite side parts.

The upper chord and/or the lower chord can be designed as flat metal sheets. In order to further increase the stability of the mast arm segment, a plurality of edges aligned in the longitudinal direction can also be introduced into the upper chord and/or the lower chord. The edges can all be bent in the same direction, so that the upper/lower chord forms a curved profile in cross-section. Edges that are bent in opposite directions to one another are also possible, so that one or more beads are formed in the top chord and/or bottom chord.

The side parts of the box-shaped profile can be arranged in a plane parallel to the force of gravity. In the case of the box-shaped profile, the side parts can be aligned parallel to one another and/or the belt surfaces can be aligned parallel to one another in a section perpendicular to the longitudinal axis of the mast arm segment.

In particular when the box section is composed of two half-shells, but also when there are a different number of sub-sections distributed over the circumference of the box section, it can be provided to create a connection between two profile parts arranged within the side part. In an embodiment, the connection is not arranged in one of the edge sections of the side part, but rather in a central section of the side part that is folded over relative to the edge section.

The connection arranged within the side part between a first profile part and a second profile part of the box profile can be designed to butt or overlap.

The connection can be made with a weld which extends along the end edge of one of the profile parts involved. The end edge of the other profile part can be bent over the central section, so that the end edge acts as an additional buckling stiffener. In relation to the box section, the buckling stiffener can be oriented inwards.

The reinforcement piece may include an end portion that terminates within the side piece. The end area can end in the form of a taper in the side part. The end area can overlap with the side part. The tip of the end portion may terminate in the central portion of the side piece. The outermost point of the end area is referred to as the tip, regardless of whether the end area tapers to a point there or has a different shape, for example rounded. The tip of the end portion may have a position spaced from a weld joint to which sections of the box section are connected. In particular, the tip of the end region can be arranged close to the neutral axis of the mast arm segment, which means that the distance between the tip of the end region and the nearest girth is at least 2 times, preferably 3 times, more preferably 2 times tor 5 is greater than the distance between the tip and the neutral axis. The end can by a circumferential Welded connection to be connected to the side panel. In order to avoid voltage peaks, the weld seam can extend beyond the end of the end area into the side part. Another measure to avoid stress peaks can be to process the reinforcement part, for example by milling, in such a way that the material thickness of the reinforcement part is reduced in one area. This can apply in particular to a region where the reinforcement part overlaps the side part. It is also possible, for the purpose of weight reduction, to produce a reduced material thickness in areas where the reinforcement part is under less stress.

The box profile may taper from proximal to distal. The taper can refer to the vertical plane and/or the horizontal plane. The length over which the box profile tapers can correspond to at least 30%, preferably at least 50%, more preferably at least 70% of the length of the mast arm segment. Proximal designates an end of the mast arm segment which, when the mast arm is in the unfolded state, is closer to the base (ie for example the truck) on which the mast arm is suspended. Conversely, when deployed, the distal end of the mast arm segment is closer to the free end of the mast arm.

The reinforcement part can form a proximal joint receptacle of the mast arm segment. A receptacle for a hinge pin can be formed in the reinforcement part. An articulated lever, to which a hydraulic cylinder can be connected, can be connected to the reinforcement part. The hydraulic cylinder has the function of pivoting the mast arm segment relative to an adjacent structure, in particular relative to a neigh disclosed mast arm segment. The articulated lever can be connected to the reinforcement part via a pivot connection. 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 amplification part.

In one embodiment, the mast arm segment comprises a first reinforcement part, which is designed as a joint mount, and a second reinforcement part, which is designed as a mount for a hydraulic cylinder. Both reinforcement parts can have the features mentioned and be connected to the side parts in the manner mentioned. The joint mount can form one end of the mast arm segment. The mount for the hydraulic cylinder can be spaced from the ends of the mast arm segment. In particular, the distance between the receptacle and the nearest end of the mast arm can correspond to at least 5%, preferably at least 10%, of the length of the mast arm segment. The distance between the first reinforcement part and the second reinforcement part can correspond to at least 10%, preferably at least 30% of the length of the mast arm segment.

The reinforcement part can extend over the width of the mast arm segment and can be connected to one of the side parts on both sides of the mast arm segment in the manner described. In particular, the reinforcing part can be designed in such a way that it does not protrude laterally beyond the upper edge portions of the side parts on both sides. In this way it can be avoided that the mast arm segment experiences an increase in width due to the reinforcement part. The reinforcement part can be a folded metal sheet. It is also possible that the reinforcement part is made in a different way, for example than Casting, forging or 3D printing. The side part can be made of sheet metal.

The mast arm segment can include a mounting seat for a holder of a conveyor line. The attachment receptacle can extend transversely through the mast arm segment and form a transverse connection between the opposite side parts of the mast arm segment. For example, the attachment mount can be welded to each of the side parts. The attachment receptacle may extend between the central portions of the opposite side pieces. In this way, the attachment receptacle can offer additional protection against the side parts of the mast arm segment deviating to the side under load. Due to the connection with the side parts, the forces exerted by the fastened elements can be introduced well into the side parts.

On one side of the mast arm segment, the attachment mount can protrude from the side panel. On this side, the mounting receptacle can be designed in such a way that a holder for the delivery line can be connected. For example, blind holes can be provided for a screw connection. But it is also possible for the holder to be welded to the fastening mount, for example. In one embodiment, the mast arm segment comprises a holder, connected to the fastening receptacle, for a conveyor line and/or a conveyor line connected to the fastening receptacle. In addition, hydraulic lines can be connected to the mast arm segment, via which, for example, hydraulic devices for folding and unfolding the mast arm can be operated. The mast arm segment can include a plurality of such attachment receptacles, in particular at least two attachment receptacles, preferably at least three attachment receptacles, more preferably at least four attachment receptacles. The attachment mounts can be substantially evenly distributed over the length of the mast arm segment. One or more of the mounting brackets may be connected to a reinforcement member.

The invention also relates to a concrete pump boom arm having a plurality of boom arm segments, at least one of the boom arm segments being designed according to the invention. A swivel joint is formed between each two adjacent boom arm segments. The axis of the pivot joint may be oriented to extend through both sides of the mast arm segment, with the two sides preferably being cut perpendicularly or at an angle of less than 10°, preferably less than 5°, with this direction. The belt surfaces can extend parallel to the pivot axis.

The linkage may include a first linkage pivotally attached to a first mast arm segment. The joint may include a second link lever pivotally attached to the second mast arm segment and also pivotally attached to the first link lever. A hydraulic cylinder can extend from the first mast arm segment to the first articulated lever, so that a lifting movement of the hydraulic cylinder is translated into a pivoting movement between the mast arm segments. The hydraulic cylinder is seen from the first mast arm segment preferably, beyond the second articulated lever on the first articulated lever. The concrete pump boom arm can include a conveying line for a thick material, in particular fresh concrete, which extends along the boom arm. A segment of the conveying line can be assigned to each segment of the boom arm. Neighboring segments of the conveying line can be connected to one another via a joint, with the joint axis preferably being coaxial with the joint with which the associated boom arm segments are connected to one another. The individual segment of the conveyor line can be designed as a rigid pipeline. The invention also relates to a method for producing a boom arm segment for a concrete pump, the boom arm segment comprising a side part which extends between an upper chord and a lower chord of the boom arm segment. A fold is formed in the side part, so that a first section of the side part has a lateral offset relative to a second section of the side part. A transition section forms a connection between the first section and the second section. A reinforcement part, the material thickness of which bridges the lateral offset between the first section and the second section, is butt-connected to the transition section.

The method can be developed with further features that are described in connection with the mast arm segment according to the invention. The mast arm segment can be developed with additional features that are described in connection with the method according to the invention.

The invention is described below with reference to the accompanying drawings based on advantageous embodiments in by way of example. Show it: 1: a concrete pump vehicle with a mast arm in the folded state;

FIG. 2: the concrete pump vehicle from FIG. 1 with the boom arm folded out; 3: a mast arm segment according to the invention; 4: a joint between two mast arm segments; Fig. 5: the proximal end of the mast arm segment from Fig.

3 in an enlarged representation;

FIG. 6 shows a detail from the mast arm segment from FIG. 3 in an enlarged representation; FIG.

FIG. 7: the distal end of the mast arm segment from FIG. 3 in an enlarged view;

FIG. 8 shows a fastening receptacle for the mast arm segment from FIG. 3 in an enlarged representation; FIG. 9: the fastening receptacle from FIG. 8 in a different perspective; FIG.

FIG. 10: the proximal end of the mast arm segment from FIG. 5 in a perspective view;

FIG. 11: the distal end of the mast arm segment from FIG. 7 in a perspective view;

Fig. 12: A cross-section along line A-A in Fig. 5.

A truck 14 shown in Fig. 1 is equipped with a concrete pump 15 which pumps liquid concrete from a hopper 16 promotes through a delivery line 17. The conveyor line 17 he stretches 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 to one another. By pivoting the mast arm segments 20, 21, 22 relative to one another via the joints, the mast arm 18 can switch between a folded state (FIG. 1) and an unfolded state (FIG. 2). The delivery line 17 extends beyond the distal end of the third boom arm segment 22 so that the liquid concrete can be discharged in an area remote from the concrete pump 15 .

Depending on the pivoting state of the mast arm, the loads act on the mast arm segments 20, 21, 22 in very different directions. In addition, the mast arm is exposed to high dynamic loads due to the intermittent conveyance of the liquid concrete.

The swivel joints between the mast arm segments 20, 21, 22 are designed in such a way that they allow a large swivel angle. The mast arm segments are in the folded state

20, 21, 22 are substantially parallel to each other and enclose a small angle between them. In the unfolded state according to FIG. 2, the mast arm segments 20 extend

21, 22 approximately in extension to each other.

The joint construction is shown in FIG. 4 using the example of the swivel joint between the first mast arm segment 20 and the second mast arm segment 21 . The hinge axis is formed by a hinge 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 hinge pin 23, a first articulated lever 24 is struck on the first mast arm segment 20. A second articulated lever 25 is attached to the second mast arm segment 21 adjacent to the articulated pin 23. gen. The two articulated levers are articulated at 26 together. 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 converted into a pivoting movement between the mast arm segments 20, 21 .

A mast arm segment 30 according to the invention shown in Fig. 3 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 parts 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. The at the side parts 35, 36 and the upper chord 33 and the lower chord 34 so approach each other with increasing distance from the proximal En de 31 to each other.

Near the proximal end 31 the mast arm segment 30 is reinforced with a first reinforcement part 40 which forms a proximal joint receptacle 57 of the mast arm segment 30 . Starting from the first reinforcement part 40, the box-shaped profile extends in the direction of the distal end 32. The box-shaped profile is composed of an upper half-shell 41 and a lower half-shell 47, which are each designed as canted metal sheets.

According to the cross-sectional view in FIG. 12, each of the side parts 35, 36 has an upper edge section 42, which adjoins the upper flange 33, and a lower edge section 43, which adjoins the lower flange 34. The upper edge portion 42 and the lower edge portion 43 are in the same plane. Between the edge sections 42, 43 is a zen tral section 44 which has a lateral offset 56 relative to the edge sections 42, 43. The Seitentei le 35, 36 are bent inwards, so that the central sections 44 of the two side parts 35, 36 have a smaller Ab stood to each other than the edge sections 42, 43 of the side parts 35, 36. Between the central section 44 and the edge sections 42, 43 are transition sections 45, 46 ausgebil det, each of which encloses an angle of approximately 30° with the plane of the edge sections 42, 43 or the plane of the central sections 44 parallel thereto.

The upper half-shell 41 comprises the upper chord, the upper edge sections 42, the upper transitional sections 45 and the upper part of the central sections 44, each from both sides 35, 36. The lower half-shell 47 comprises the lower chord 34, the lower edge sections 33, the lower transition sections 46 and the lower part of the central section 44 from both side parts 35, 36. The upper end of the lower half-shell 47 overlaps with the lower end of the upper half-shell 41 which the two half-shells 41, 47 are connected to each other. The lower half-shell 47 is folded inward with its end edge 55 and forms there with a buckling stiffener for the box profile.

The first reinforcement part 40 has a greater material thickness than the box profile made up of the half-shells 41, 47, see Fig.

12. The outside of the first reinforcement piece 40 coincides with the outside of the upper edge portions 42. FIG. The inner side of the first reinforcement part 40 coincides with the outer side of the central portions 44 . With the transition sections 45, 46, the box profile changes between the outside and the inside of the first reinforcement part 40. The transition sections 45, 46 and the edge sections 42, 43 are butt welded to the first reinforcement part 40. The central sections 44 overlap with the first reinforcing part 40. The connection between the first reinforcing part 40 and the central sections 44 is formed by a circumferential weld seam around the first reinforcing part 40.

In FIG. 12, a straight line that extends in the longitudinal direction of the side part is essentially perpendicular to the plane of the drawing. In the area of an upper edge section 42, where the connection to the reinforcement part 40 is butt-jointed, a straight line extending inside the upper edge section 42 intersects in the area of the butt joint an end face of the upper edge section 42 and an end face of the reinforcement part 40. The same applies in Area of the transition sections 45, 46 and in the area of the lower edge portions 43 that such a straight line intersects the corresponding end faces. In contrast to this, the connection to the central sections 44 is designed to overlap, so that the inside of the reinforcement part 40 is flush with the outside of the central sections 44 . A straight line extending longitudinally within the central portion 44 does not intersect the end face of the reinforcement member 40 but extends at a distance to the inside of the reinforcement member 40.

According to Fig. 5, 10 in the first reinforcement part 40 a hinge hole 37 is formed. The hinge bore accommodates the Ge pivot pin 23 which connects the mast arm segment 30 to a neighboring mast arm segment. A stud 38 is arranged next to the joint bore 37, to which the joint lever 25 is connected. Correspondingly, the mast arm segment 30 includes a further joint bore 37 near its distal end such as another stud 38 to which an articulated lever 24 can be connected.

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 reinforcing part 50 thus overlaps with the central sections 44 of the side parts 35, 36 and is connected there to the upper half-shell 41 by a circumferential weld seam. The upper transition section 45 and the upper edge section 42 are butt welded to the second reinforcement part 50 .

The distal joint mount 51 shown in FIGS. 7 and 11 comprises a reinforcement plate 52 which is doubled onto the plate of the box profile. The connection between the reinforcement plate 52 and the box section is formed by a circumferential weld seam which extends over the circumference of the reinforcement plate 52 . The joint mount 51 includes a joint bore 37 which receives the joint pin 23 for the connec tion with an adjacent mast arm segment. A stud 38 is arranged next to the joint bore 37, to which the joint lever 25 is connected.

According to FIG. 3, the mast arm segment comprises a plurality of fastening receptacles 53 for attaching holders (not illustrated) for the conveying line 17. A first fastening receptacle 53 is connected to the first reinforcement part 40. In the side parts 35, 36 of the box profile, two further mounting receptacles 53 are arranged. A fourth mounting receptacle 53 is net angeord near the distal joint receptacle 51 . According to FIGS. 8 and 9, the fastening receptacle 53 forms a cross connection 54 between the first side part 35 and the second side part 36. The cross connection 54 is formed by a piece of pipe which is welded to the central sections 44 of both side parts 35,36. Since the side parts 35 , 36 are held at a fixed distance from one another by the pipe section 54 , the fastening mounts 53 counteract buckling of the mast arm segment 30 .

On the side of the first side part 35 the tube piece 54 ends as a tube stub which protrudes slightly in relation to the central section 44 of the side part 35 . On the side of the second Be tenTeil 36, the mounting bracket 53 is provided with four threaded holes to which the holder for the delivery line can be screwed.

Claims

patent claims

1. Boom arm segment for a concrete pump, the boom arm segment (30) comprising a side part (35, 36) which is located between an upper flange (33) and a lower flange (34) of the boom arm segment (30 ) extends, and in the side part (35, 36) is formed a fold, so that a first

Section (42, 43) of the side part (35, 36) has a lateral offset (56) relative to a second section (44) of the side part (35, 36), and with a transition section (45, 46) which has a connection between the first section (42, 43) and the second section (44), the mast arm segment (30) forming a reinforcement part (40,

50), the material thickness of which bridges the lateral offset (56) between the first section (42, 43) and the second section (44), and wherein the reinforcement part (40, 50) butts against the transition section (45, 46) ver is bound.

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

3. mast arm segment according to claim 1 or 2, characterized in that the reinforcing part (40, 50) butt to the first portion (42, 43) of the side part (35, 36) is connected ver.

4. mast arm segment according to one of claims 1 to 3, characterized in that the reinforcing part (40, 50) overlaps with the second section (44) of the side part (35, 36).

5. mast arm segment according to claim 4, characterized in that the reinforcing part (40, 50) by a weld connected to the second portion (44) of the side member (35, 36) which extends along a portion of a peripheral edge (58) of the reinforcement member (40, 50).

6. Mast arm segment according to one of Claims 1 to 5, characterized in that the first section (42, 43) forms an edge section of the side part (35, 36) which is attached to the upper chord (33) or the lower chord (34) of the Side part (35, 36) is adjacent.

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

8. mast arm segment according to claim 6 or 7, characterized in that the side part (35, 36) comprises an upper edge section (42) and a lower edge section (43) and that the reinforcement part (40) cut with the upper edge section (42) and the lower edge portion (43) is welded.

9. Mast arm segment according to one of Claims 1 to 8, characterized in that the first section (42, 43), the transition section (44) and the second section (45, 46) of the side part are elements of a shell component (41, 47) are, in which the shell component (41, 47) cut a surface section of the upper chord (33) or the lower chord (34) summarizes.

10. mast arm segment according to one of claims 1 to 9, characterized in that the mast arm segment (30) comprises a box profile with an upper chord (33), a lower chord (34) and two between the upper chord (33) and the bottom chord (34) arranged side parts (35, 36), and that the box profile is composed of half-shells (41, 47), with a first half-shell (41) having the upper chord (33) and one upper edge section (42) each and an upper transition section (45) of the opposite side parts (35, 36) and wherein a second half-shell (47) includes the lower chord (34) and a lower edge section (43) and a lower transition section

(46) of the opposite side parts (36).

11. Mast arm segment according to claim 10, characterized in that the first half-shell (41) and the second half-shell

(47) are connected to each other in the central portion of the side part.

12. mast arm segment according to claim 10 or 11, characterized in that an end edge (55) of the second half-shell (47) relative to the central portion (44) is bent to form a buckling stiffener for the box profile.

13. Mast arm segment according to one of Claims 10 to 12, characterized by a fastening receptacle (53) for a holder of a conveyor line (17), the fastening receptacle having a cross connection (54) between the opposite side parts (35, 36) of the Mast arm segment (30) forms det.

14. Mast arm segment according to one of claims 1 to 13, characterized by a marked first reinforcement part (40) which is designed as a joint mount (57) and a second reinforcement part (50) which serves as a mount (28) for a hydraulic lik cylinder is designed.

15. A method for producing a boom arm segment for a concrete pump, the boom arm segment (30) having a side part (35, 36) which extends between an upper chord (33) and a lower chord (34) of the mast arm segment (30), and in the side part (35, 36) forms a fold out so that a first Section (42, 43) of the side part (35, 36) has a lateral offset (56) relative to a second section (44) of the side part (35, 36), and with a transition section (45, 46) which forms a connection between the first section (42, 43) and the second section (44), with a reinforcement part (40, 50), the material thickness of which compensates for the lateral offset (56) between the first section (42, 43) and the second section section (44) is bridged, butted to the transition section (45, 46).