Device for the internal bending of pipes for pipelines

Abstract

The invention relates to a device for the internal bending of pipes (100), more particularly coated pipes, for pipelines, the device comprising a main body (11), which can be positioned in the pipe and which has, on at least one side (12), preferably the bottom side, at least one contact surface (13) for contacting an inner wall (101) of a pipe (100) to be bent, wherein the main body (11) has a side opposite from the contact surface (13), preferably the top side, on which at least one tool for applying a bending force to the pipe (100) is movably provided, which tool can be moved relative to the main body (11) by means of at least one actuator (18, 20) in order to apply the bending force. According to the invention, the tool is provided as a tool element (21) which has at least two bending-force application portions (28, 29) for applying the bending force to the pipe (100), which bending-force application portions can be moved relative to the main body (11) by means of at least one actuator (18, 20) each.

Description

[0001] The invention relates to a device for the internal bending of pipes, in particular coated pipes, for pipelines, comprising a base body that can be positioned in the pipe and has at least one support surface with an inner wall of a pipe to be bent on at least one side, preferably the underside. The base body has a support surface on the opposite side, preferably the upper side, on which at least one tool for introducing a bending force into the pipe is movably provided. The tool is movable relative to the base body via at least one actuator for introducing the bending force. The tool is provided as a tool element that has at least two bending force introduction sections for introducing the bending force into the pipe, each of which is movable relative to the base body by at least one actuator. The at least two bending force introduction cuts (28) are provided in the outer region of the tool element.

[0002] These pipes are used in pipelines that carry large quantities of liquids or gases over long distances. The media transported include petroleum, chemicals, and / or water. Other pipes made of various materials, such as copper, stainless steel, brass, etc., can also be bent. This technique is particularly suitable for pipes with a relatively thin wall thickness relative to their diameter, as these would otherwise be very difficult or impossible to bend.

[0003] Pipelines for transporting both liquid and gaseous substances over long distances exist throughout the world. These pipelines are generally made up of sections of individual pipes ranging in length from 6 to 18 meters. The pipes usually have a diameter of 101.6 mm to well over 1905 mm (4 to well over 75 inches) and are welded together to form a pipeline, laid on the earth's surface, underground, and / or underwater. Pipelines often follow the general contour of the earth's surface. The course of the pipelines, particularly in their horizontal and vertical extensions, can also be diverted or otherwise guided around obstacles.

[0004] A major challenge in the planning and construction of such pipelines is joining the ends of the individual pipes using high-quality welds. In order to follow the contours of the earth's surface and avoid any obstacles in the pipeline's route, changes in direction within the pipeline are necessary. When creating these changes in direction, we try to avoid welded joints wherever possible. Changes in direction in pipelines can be created, especially in pipes with a large diameter, by welding individual pipe sections together with miter cuts. To minimize the number of welds and thus increase the reliability of the pipelines, the change in direction in the pipe must be created by bending the pipe. In addition, the curved pipes enable significantly greater flexibility on the construction site and much tighter radii when routing the pipeline.

[0005] As is common with large-diameter pipes, a bend is achieved by performing numerous small, ordered bending steps in the pipe. The desired bend radius is thus created in the shape of a polygon, even if this is ideally not recognizable on the finished bend. With this type of bending system, the operator has complete control over the number of incremental and / or step bends to be created, the spacing between the incremental and / or step bends, and the extent of each incremental and / or step bend in the pipe. Experienced operators can efficiently control the pipe bending machines to create precise bends in the pipes, minimizing the number of damaged or incorrectly bent pipes, which result in a waste of time and raw materials such as energy and pipes.

[0006] After each bending process, the tube and bending fixture must be moved relative to each other with high precision. This can involve both moving the tube within the bending fixture and moving the bending fixture itself. The latter option has the disadvantage that the tube must be realigned within the bending fixture. Moving large-diameter tubes, precisely repositioning the mandrel, and checking the resulting bend require significant personnel and energy expenditure.

[0007] Due to the size of the pipes to be bent, bending devices are generally massive in nature and are operated hydraulically.

[0008] A bending device is generally known from US Pat. Nos. 3,834,210 and 5,092,150. Such bending devices have devices for gripping the pipe, moving the pipe within the bending device, and creating the bend in the pipe. These devices are all hydraulically operated under the control of an operator.

[0009] DE 600 28 484 T2 shows a conventional bending device adapted for creating bends in a large-diameter pipe. The bending device generally includes a reinforced frame to which the components are anchored against relative movement. The main components of the pipe bending device include a bending tool, a mandrel, a support device, and a fastening shoe. The bending tool is a solid body that is stationary with respect to the frame and has a curved surface facing the pipe, whereby the pipe is pressed against the bending tool during the bending process. The support device is actuated by hydraulic pressure during the bending process and pivoted towards the bending tool. The fastening shoe, meanwhile, fixes the pipe.During the bending process, forces are transferred to the pipe by means of the bending tool, the support device, and the clamping shoe in the working areas of the bending device, causing it to deform. The mandrel is a flexible, link-based structure that allows the pipe to be bent without altering its circular shape at the bend point. Such mandrels are well known in the art and are typically composed of spring steel strips / sheets.

[0010] As the bending device mentioned above demonstrates, bending devices typically have three working areas in which the forces required to bend the pipe are transferred to the pipe. During the bending process, active force is applied in one working area by means of a hydraulic cylinder. The remaining passive working areas serve as abutments and are connected to the active working area via the frame. DE 696 03 499 T2 shows a bending device in which the middle of the three working areas is designed as the active working area.

[0011] Bending such large-diameter pipes requires considerable force. The necessary bending devices and mandrels must be correspondingly large and robust. The equipment required for such large bending devices, such as diesel generators, hydraulic pumps, and mandrels, is also large in volume and heavy in weight. Overall, the operation of such (external) bending devices places considerable demands on space requirements during transport and at the site of use. In addition to the high logistics costs, there are also the costs for consumables, especially fuels and energy sources.

[0012] To reduce labor costs, DE 600 28 484 T2 also discloses a method for automating a bending device and a control system with a programmable processor. Automation is particularly necessary to perform incremental and / or step-by-step bends with a high degree of repeatability and accuracy. To achieve higher quality, the duration of the entire bending process should be reduced, thus simultaneously reducing the transport weight and energy consumption of the bending device.

[0013] A device mentioned above and a corresponding method are known from DE 10 2008 060 897. This device provides a bending device which, at least with its essential parts for the function of the bending machine, can be positioned entirely inside the pipe to be bent. This allows the bending device to apply the forces required to bend the pipe from the inside. This results in low labor and energy consumption. Furthermore, damage to a coating applied to the outside of the pipe, such as paint, thermal insulation, and / or synthetic resin reinforcement, is fundamentally avoided.

[0014] JP S58138523 A also discloses a bending device that performs the bending inside the pipeline. This device has two active working areas (front and rear), while the central working area is passive. Here, the precise application of force to both separate working areas is disadvantageous.

[0015] DE 10 2012 012 139 A1 discloses an internal pipe bending device in which at least three contact elements are provided on a support, two contact elements being arranged on a first side of the support at the ends of the support, and one contact element being arranged on a second side of the support opposite the first side in the center of the support. This allows the bending device to be movable within the pipe like a rocker.

[0016] A bending device of the type mentioned above is known from GB12740059A. A method for cold bending pipes is disclosed, comprising inserting a device with bending elements into the pipe, bending the pipe by actuating the elements, and freely moving the device within the pipe after bending for the next bending operation. The disclosed device comprises a rigid frame mounted on spring-loaded wheels and driven by the pipe by means of an electric motor via a reduction gear connected to one of the wheels. A bending shoe is attached to the center of the frame, facing the stretched section of the pipe. The bending elements, consisting of two hydraulic cylinders pivotally mounted on rollers and held in the vertical position by springs, are located at the ends of the frame. The cylinders carry articulated segment heads.An expansion mechanism is installed in the center of the frame to improve the stability of the pipe wall under pressure during bending. It consists of three vertical and six horizontal hydraulic cylinders supporting articulated bent segment heads.

[0017] The invention is based on the object of creating a bending device that can bend pipes from the inside with significantly higher forces and, at the same time, with greater precision. Furthermore, the design of the machines should be simplified to achieve the longest possible service life.

[0018] The object is achieved by the device according to claim 1, wherein the tool element has at least one elastic section between the at least two bending force introduction sections, via which the bending force introduction sections are connected to one another.

[0019] This allows the bending energy to be optimally introduced into the pipe to be bent in a particularly simple and precise manner.

[0020] The device according to the invention also provides that the tool element has a contact section located between two outer bending force introduction sections, preferably centrally. This section is preferably connected to the two surrounding sections. This allows the pipe to be easily supported during bending to prevent unwanted deformations.

[0021] It is advantageous that the third contact section is movable via one or more actuators, particularly in the radial direction. This allows the support effect in the area of ​​plastic deformation of the tube to be particularly advantageously controlled.

[0022] The device according to the invention also provides that the bending force introduction sections and / or contact sections are inherently elastically deformable and / or capable of expanding. This makes it easy to counteract ovalization.

[0023] A further teaching of the invention provides that at least one elastic section is provided between the at least two bending force introduction sections, and / or the middle contact section is inherently elastic in the direction of the bending to be generated.

[0024] It is advantageous for the elastic section to be provided by reducing the material in the tool element, preferably in the form of recesses in the tool element. A preferred embodiment of this is to provide the elastic region in the form of ribs and recesses between the ribs. The ribs are particularly advantageously designed to allow the necessary deformations while simultaneously absorbing the necessary supporting forces. The ribs can also take on free shapes that specifically allow the desired deformations. These are determined, for example, using topology optimization on the computer.

[0025] It is further advantageous that the at least one area with a material reduction in the tool element is at least partially filled with an elastic material. Preferably, the aforementioned ribs and recesses are completely or partially filled with an elastic material. The elastic material is compressed in the ribs during bending and thereby forced out of the ribs. This provides additional support for particularly thin-walled pipes.

[0026] A further teaching of the invention provides that the actuators are hydraulic cylinders or similar linear actuators such as pneumatic cylinders, threaded spindles, and / or piezo elements. This allows the force to be applied directly into the pipe particularly effectively and without losses.

[0027] A further teaching of the invention provides hydraulic cylinders with one or more pistons arranged one behind the other. The pistons can be housed in a single or several separate cylinder blocks and act on a common force transmission element. This element is either part of the upper tool element or transmits the force there and is rotatably mounted relative to the upper tool to prevent excessive forces on the cylinders.

[0028] A further teaching of the invention provides that the actuator moves the tool element away from the base body, preferably upwards, and in an arc from the base body toward the inner wall of the pipe. This ensures that there is no relative displacement between the tool and the pipe, nor between the actuator and the tool. Due to its elasticity, the tool precisely follows the contour of the pipe's inner surface and compresses to the same extent.

[0029] A further teaching of the invention provides that the actuators move the outer bending force introduction sections of the tool element upward and in an arc from the base body toward the inner wall of the pipe. This ensures that there is no relative displacement between the bending force introduction sections and the pipe, nor between the actuator and the bending force introduction sections. Due to its elasticity, the tool precisely follows the contour of the pipe's inner surface and compresses to the same extent.

[0030] It is further advantageous that the actuators and the bending force introduction sections of the tool element are arranged and designed such that the actuators can move the outer bending force introduction sections of the tool part away from the base body, preferably upwards, and in an arc from the base body towards the inner wall of the pipe.

[0031] A further feature of the invention provides for the lower contact surface to be curved. This allows the optimal bending of the tube to be easily specified.

[0032] A further teaching of the invention provides for a carriage for movement within the pipe to be provided on the base body. This allows the bending device to be easily moved within the pipe.

[0033] A further teaching of the invention provides that the carriage has at least two carriage elements, preferably with rollers, which are preferably located on the end faces and / or in front of and behind the lower contact element and are retractable, preferably via spring elements. This allows for safe movement within the interior of the pipe in a simple manner.

[0034] A further teaching of the invention provides that at least one chassis element is arranged in the region of the lower contact element and is arranged to be retractable into the main body via a spring force. It has been shown that this easily eliminates the need for active raising / lowering.

[0035] A further teaching of the invention provides at least one push rod and / or push chain for pushing and pulling the bending device into and out of the pipe to be bent. This push rod and / or push chain is attached to a base outside the pipe and can be driven from there via a mechanism. This allows for a simple movement of the bending device within the pipe.

[0036] A further feature of the invention provides that the position of the machine in the pipe can be detected via the push rod / push chain. This allows for simple, precise control of the position of the device in the pipe.

[0037] A further teaching of the invention provides that the push rod / push chain is held torsionally rigidly on a base outside the pipe. This largely prevents or at least captures any twisting of the bending device within the pipe.

[0038] A further teaching of the invention provides at least one roller in the upper region of the base body and / or tool. This roller is not spring-mounted like the lower rollers, but protrudes above the tool geometry at an adjustable distance. After the first bending step, the roller(s) simply prevent the tool element from contacting the pipe as soon as the lower rollers push the machine upwards using spring force.

[0039] A further teaching of the invention provides that the tool is at least partially slotted in its longitudinal direction in order to enable a slight elastic expansion in the radial direction.

[0040] A further teaching of the invention provides that the base body and / or the tool element are constructed in two parts, preferably in the form of an inner base body and an outer base body and / or an inner tool element and an outer tool element.

[0041] A further teaching of the invention provides that the tool element is constructed in several parts, wherein the tool element is constructed from at least two bending force introduction section parts and a contact section part, which is preferably designed to be elastic, which are connected to one another.

[0042] It is advantageous that the contact section part consists of at least two beams, that the beams are connected to the at least two bending force introduction section parts, and that at least two rib elements are arranged on the beams.

[0043] It is also advantageous that the rib elements are arched and rest on one side of each beam. The connection is preferably loose. Alternatively, it is advantageous for the rib elements to have a positive connection to the beam. This prevents significant deformation of the ribs and achieves a better support effect in the pipe.

[0044] It is also advantageous that the at least two rib elements are spaced apart, creating a gap. This allows the rib elements to move into the gap and toward each other.

[0045] It is particularly advantageous that at least one elastically deformable element is provided in the gap. This element can deform elastically as the ribs move into the gap, support the rib elements, and / or move outward in a bulge-like manner, thus providing support for the pipe to be bent.

[0046] A further teaching of the invention provides that at least one actuator is provided in the region of the contact section. Advantageously, one actuator is arranged centrally under each of the at least two beams.

[0047] The invention is explained in more detail below using a preferred embodiment in conjunction with a drawing. The drawings show: Figure 1 shows a side view of a first embodiment of a bending device according to the invention in a pipe to be bent, Figure 2 shows a spatial representation of Figure 1 , Figure 3 a sectional view to the longitudinal axis Figure 1 , Figure 4 a sectional view of a part of the first embodiment of the device according to the invention transverse to the longitudinal axis, Figure 5 a side view of a second embodiment of a bending device according to the invention with chassis, Figure 6 a second side view of Figure 5 , Figure 7 a side view of a third embodiment of a bending device according to the invention with chassis and push rod, Figure 8 a spatial representation of Figure 7 , Figure 9 a spatial representation of a guide of a push rod to Fig. 7 and 8, Figure 10 a side view of a fourth embodiment of a bending device according to the invention with chassis and protruding bending tool, Figure 11 a spatial partial view of Figure 10 , Figure 12 a side view of a fifth embodiment of a bending device according to the invention with chassis, projecting bending tool and covers of the contact sections Figure 13 a spatial representation of Figure 12 , Figure 14 a side view of a basic version without covers for the embodiment to Figure 13 , Figure 15 a spatial representation of Figure 14 , Figure 16 a sectional view to the longitudinal axis Figure 13 , Figure 17 is a side view of a sixth embodiment of a bending device according to the invention, Figure 18 is a sectional view of a part of the sixth embodiment of the device according to the invention transverse to the longitudinal axis, and Figure 19 is a partial view of Figure 17 in the bending state.

[0048] Figure 1shows a first pipe bending device 10 according to the invention with a base body 11. The base body 11 has a bottom side 12. The bottom side 12 has a lower contact surface 13 in the center. The bottom side 12 is preferably completely curved.

[0049] A partially arched design is also possible as an alternative.

[0050] Also possible but not shown is a pipe bending device 10 tilted by up to 90 degrees for horizontally bending the pipe 100.

[0051] The curved shape is designed so that the radius is narrower than the final intended radius of a fully bent tube 100. The bend of the underside 12 is essentially convex. The shape of the contact surface 13 can be designed as a freeform to achieve optimal roundness of the tube after bending.

[0052] Preferably, the base body 11 is constructed in one piece. Alternatively, the base body can be split longitudinally, for example, to facilitate the manufacture of the base body 11.

[0053] Furthermore, the base body 11 has an upper side 14, which here is preferably curved with a maximum above the lower contact surface 13. The upper side 14 has a concave shape on the end faces 15 of the pipe bending device 10, as shown in Figure 2 The base body 11 is preferably designed so that it can absorb the highest possible forces while simultaneously providing sufficient space for the necessary attachments and a tool element 21.

[0054] Inside the base body 11, recesses 16 are provided on a front and a rear side of the base body 11, which recesses are connected to a channel 17. Actuators 18, preferably hydraulic cylinders here, are arranged in the recesses 16, which can be extended upwards in the direction of arrow A and retracted in the opposite direction to the direction of arrow A.

[0055] In addition, as shown here in Figure 3 As shown, in the region of the lower contact surface 13 in the upper side 14, between the recesses 16, further recesses 19 may be provided, in which one or more further actuators 20, here preferably a hydraulic cylinder, are arranged. This can also be extended and retracted in the direction of arrow A.

[0056] Channel 17 may contain connecting lines (not shown) between actuators 18 for power supply and control. A connection (not shown) also exists, if provided, to actuator 20 or other actuators. These are preferably hydraulic lines and valves, as well as cables for sensors or electrically driven actuators, and for connecting chassis lines if necessary.

[0057] A tool element 21 is arranged on the upper side 14. This tool element has a lower side 22, which preferably corresponds to the upper side 14 of the base body 11 such that it can be arranged on the upper side 14 of the base body 11. The lower side 22 of the tool element 21 has corresponding recesses 23, which are arranged above the recesses 16. Furthermore, the lower side 22 has a recess 24, which is correspondingly arranged above the recess 19 when the tool element 21 is arranged on the base body 11.

[0058] The recesses 23, 24 each have a contact surface 25, 26 against which a contact surface 36 of one of the actuators 18, 20 acts during its movement in the direction of arrow A and on which the actuator 18, 20 accordingly exerts a force in the direction of arrow A.

[0059] Furthermore, the tool element 21 has an upper surface 27. The upper surface 27 is preferably designed such that it substantially coincides with the inner radius of the pipe 100 to be bent in the contact area with the inner wall 101 of the pipe 100. When unloaded, the radius can be smaller or the same size so that the pipe bending device 10 can be extended and retracted into the pipe. When loaded, the radius can, for example, widen if necessary.

[0060] Preferably, the upper side 27 has two outer bending force introduction sections 28 and a central contact section 29.

[0061] The outer bending force introduction sections 28 and the central contact section 29 are preferably separated from each other by elastic deformation sections 30.

[0062] Furthermore, the tool element 21 preferably consists of a single, continuous part or several mechanically interconnected parts. The tool element 21 is designed to be elastic at least in the center to follow the inner wall 101 of the tube 100 during bending. Several elastic deformation sections 30 can also be provided next to the center of the upper part to apply a stronger / different force to the inner wall 101 of the tube 100. The force and position of the force application from the tool element 21 to the tube 100 can be adjusted via the elasticity and original shape of the tool element 21.

[0063] The elastic deformation sections 30 preferably have ribs 31 and recesses 32 that extend in the circumferential direction on the upper side 27 of the tool element 21. The recesses 32 have a width B. The recesses 32 are preferably designed with different depths depending on the elasticity to be achieved in the deformation section 30. In Figure 3 The recesses 32 become deeper with increasing distance from the central contact section 29. Here, the depth is preferably selected such that the distance between the deepest point 33 of the recess 32 and the underside 22 of the tool element 21 is constant relative to the respective recess 32. Alternatively, the distances can be varied depending on the desired elasticity.

[0064] If the actuators 18, 20 are extended in the direction of arrow A, the upper side 27 of the tool element 21 is first moved against the inner wall 101 of the tube 100 until the bending force introduction sections and the middle contact section 28, 29 and, if applicable, also the upper sides 34 of the ribs 31 rest against the inner wall 101.

[0065] The central contact section 29 serves to support the transformation of the tube 100 in order to prevent deformation of the tube that deviates from maintaining the circumferential shape of the tube 100. It has been shown that it is advantageous if the central contact section 29 is also designed to be elastically deformable.

[0066] Furthermore, it has been found that, for improved support, it is advantageous to provide an actuator 20, preferably a hydraulic cylinder, which can exert a force in the direction of arrow A via the central contact section 29 onto the inner wall 101 of the tube 100 during bending. The actuator 20 can optionally be used to precisely control the support effect of the central region, for example, for very thin-walled tubes.

[0067] In an alternative embodiment, the outer bending force introduction sections 28 and the central contact section 29 can be designed as individual components. Recesses / spaces can be provided between the bending force introduction sections 28 and / or the central contact section 29. Alternatively, a hinged connection can be provided between the sections 28, 29 instead of the elastic sections to enable more precise guidance.

[0068] If actuators 28 are now extended in the direction of arrow A, the outer contact elements 28 exert a force on the inner wall 101 of the tube 100. As soon as a limit force is exceeded, the outer bending force introduction sections 28 move together with the tube 100 in the direction of arrow D until the curved underside 12 of the base body 11 comes into contact with the inner wall 101 of the tube 100 at its outer sections 35. The tube 100 deforms both elastically and plastically. As the outer bending force introduction sections 28 move in the direction of arrow D, the width B between the ribs 31 in the recesses 32 decreases.

[0069] If the actuators 28 are now moved back in the opposite direction of arrow A, the outer bending force introduction sections 28 move in the opposite direction of arrow D. The tube 100 also moves in the opposite direction of arrow D to reduce the elastic deformation until the elastic deformation is reduced and only the plastic deformation of the tube 100 remains. Meanwhile, the width B of the recesses 32 between the ribs 31 widens accordingly.

[0070] Once the actuators 18 are fully retracted, the underside 22 of the tool element 21 preferably rests completely on the upper side 14 of the base body 11. Subsequently, the pipe bending device 10 is moved in the pipe 100 to the next bending point, and the previously described process is repeated.

[0071] Springs or similar return elements can be provided to return the tool element 21 to its original position. Additionally, guide elements can be provided that hold the tool element 21 in position relative to the base body 11, while simultaneously allowing elastic movements of the tool element 21 as well as movements in the vertical direction.

[0072] Advantageously, the contact surfaces 25, 26 of the recesses 23, 24 are designed in the shape of a cylindrical segment or a spherical segment. Furthermore, it is advantageous that the contact surfaces 36 of the actuators 18, 20 are also designed in the shape of a cylindrical segment or a spherical segment. It is advantageous if the shape of the contact surfaces 36 is flatter than the shape of the contact surfaces 25, 26. This is shown in Figure 4This causes an outer bending force introduction section 28 and / or a central contact section 29 to deform / expand in the direction of arrow E when the actuator 18, 20 is moved in the direction of arrow A, in order to then adapt to the shape of the inner wall 101 of the tube 100 in such a way that a cross-sectional deformation of the tube 100 is counteracted.

[0073] Figure 5 shows a second pipe bending device 10 according to the invention with an identical structure to the first in the Figures 1 to 4 shown embodiment of the invention.

[0074] Additionally, the second embodiment features a chassis. This comprises a chassis element 41 on each of the end faces 15 and rollers 42 mounted on the upper side 14 of the base body 11. These rollers are arranged on a support (not shown) and each extend through an opening 40 in the upper side 27 of the tool element 21.

[0075] The chassis element 41 comprises a base body 43 connected to the end face 15. The base body 43 is movably connected in the direction of arrow F to a support element 44. Rollers 45 are arranged on the support element 44, preferably at an angle relative to the perpendicular bisector of the pipe bending device in accordance with the pipe inner diameter, with the rollers 45 being arranged on the support element 44 via supports 46.

[0076] The base body 43 is connected to the support element 44 via preload elements 47, which here are preferably spring elements 48, each arranged on a guide 49. The spring elements can also be arranged independently of the guide.

[0077] The rollers 45 rest on the inner pipe wall 101 as the pipe bending device 10 moves. Once the bending point is reached, the tool element 21 is pressed in the direction of arrow A against the inner pipe wall 101 via the actuators 18, 20. The tool element 21 is moved past the rollers 42 as they move through the openings 40. When the upper side 27 with the bending force introduction sections 28 reaches the upper inner wall 101, it is pressed against it. This applies a counterforce to the prestressing element 47, so that the support elements 44 move relative to the base bodies 43 in the direction of arrow F, with the spring elements 48 preferably being compressed here. This moves the underside 12 with the contact surface 13 towards the inner pipe wall 101 until the contact surface 13 rests against it and the pipe bending process can begin as described above. After the pipe bending is completed, the process is reversed.

[0078] The Figures 7 to 9show a third embodiment of a pipe bending device 10 according to the invention with an identical structure to the first in the Figures 1 to 6 shown first and second embodiments of the invention.

[0079] Additionally, a preferably torsionally rigid push rod 50 is provided, which is connected to an attachment element 51, for example, on the end face 15 of the pipe bending device 10, for example, via a joint 52. The connection is suitable for transmitting pushing and pulling forces, for example, in the direction of arrow G, which are generated by a drive (not shown) and transmitted via the push rod 50 in order to move the pipe bending device 10 in the pipe 100 in the direction of arrow G. The push rod is provided here, for example, with a square cross-section. Figure 9 shows a base element 53, here preferably provided with rollers 54 for driving, guiding and stabilizing the push rod 50.

[0080] The Figures 10 and 11 show a fourth embodiment of a pipe bending device 10 according to the invention with an identical structure to that shown in the Figures 1 to 6 shown first and second embodiments of the invention. The features of the third embodiment may be added here, but are not shown.

[0081] In addition, the tool element 21 is designed longer than the base body 11, creating an overhang area 60 that extends over the chassis elements 41. This easily enlarges the bending area, reducing the surface pressure in the tube and thus potentially allowing the desired final bend to be achieved with fewer bending steps.

[0082] The Figures 12 to 16 show a fifth embodiment of a pipe bending device 10 according to the invention with an identical structure to that shown in the Figures 1 to 4 and 10 , 11shown first and fourth embodiments of the invention. Only the ribs 31 of the tool element 21 are flat here. The features of the second and third embodiments can be added here, but are not shown.

[0083] The base body 11 and the tool element 21 are constructed in two parts. They each comprise an inner base body 11a and an outer base body 11b, as well as an inner tool element 21a and an outer tool element 21b. The inner base body 11a and the inner tool element 21a form the basic structure of the pipe bending device 10 and are preferably made of steel. The base body 11a here, for example, has a flat, non-bent underside 12.

[0084] On an underside 12a of the base body 11a, a lower covering element 61, preferably made of plastic, is provided as the outer base body 11b, which also includes the support surface 13. On the upper side 27a of the inner tool element 21a, an upper covering element 62, preferably made of plastic, is provided as the outer tool element 21b, wherein the covering also has the bending force introduction sections 28. The structure and function of the pipe bending device 10 of the fifth embodiment otherwise correspond to those described above.

[0085] The covering elements 61 and 62 can also be designed as a further embodiment as a coherent elastic plastic part.

[0086] A sixth embodiment of the device 10 according to the invention is shown in the Figures 17 to 19 The structure of the base body, including the actuators 18, 20, corresponds to the structure described above.

[0087] The tool element 21 has an upper surface 27. The upper surface 27 is preferably designed such that it substantially coincides with the inner radius of the pipe 100 to be bent in the contact area with the inner wall 101 of the pipe 100. When unloaded, the radius can be smaller or the same size so that the pipe bending device 10 can be extended and retracted into the pipe. When loaded, the radius can expand, for example, if necessary.

[0088] Preferably, the upper side 27 has two outer bending force introduction sections 28 and a central contact section 29. The bending force introduction sections 28 and the central contact section 29 are designed as individual components 60, 61.

[0089] Preferably, the components 60, 61 are connected to one another via a connecting element 62. This connection is particularly preferably made via a force-locking and / or positive connection.

[0090] The contact section element 61 is preferably constructed from two parallel bars 63. The bars can be made in one piece or from multiple parts. The single-piece design is shown here. Furthermore, multiple bars can also be arranged one above the other.

[0091] The beams 63 are preferably connected to the connecting element 62. This connection is particularly preferably made via a force-locking and / or positive connection.

[0092] Rib elements 64, corresponding to the ribs 31, are arranged on the beams 63. These are preferably curved. Furthermore, the rib elements 64 preferably sit loosely on an upper side 65 of the beams 63. The ribs are preferably connected to the beam elements 63 in a radial direction via a positive fit.

[0093] A distance 66 is preferably provided between two rib elements, corresponding to the recesses 32. An elastic element 67 is particularly preferably provided in this distance 66.

[0094] Furthermore, it has been found that it is advantageous for improved support that an actuator 20', preferably a hydraulic cylinder, can be provided here (see the detail view part in Fig. 17 ), which can exert a force A via the central contact section 29 onto the inner wall 101 of the tube 100 during bending. The actuator 20' can optionally be used to precisely control the supporting effect of the central region, for example, for very thin-walled tubes. For this purpose, at least one actuator 20' is provided below at least one beam 63.

[0095] If a bending force is introduced into the tool part 21 via the actuators 18, the beams 63 bend, as shown in Fig. 18As a result, the rib elements 64 move toward each other and squeeze the elastic elements 67, which thereby each form a bead 68 outwardly. The bead 68 presses against the tube 100 and additionally supports it.

Claims

1. Device for internal bending of pipes (100) for piping, having a main body (11) which is positionable in the pipe and which, on at least one side (12), has at least one bearing surface (13) with respect to an inner wall (101) of a pipe (100) to be bent, wherein the main body (11) has a side which is situated opposite the bearing surface (13) and on which at least one tool for introducing a bending force into the pipe (100) is movably provided, wherein the tool is movable in relation to the main body (11) via at least one actuator (18, 20) for introducing the bending force, wherein the tool is provided as a tool element (21) which has at least two bending-force-introducing portions (28) for introducing the bending force into the pipe (100), these being movable relative to the main body (11) by in each case at least one actuator (18, 20), and wherein the at least two bending-force-introducing portions (28) are provided in the outer region of the tool element (21), characterized in that, between the at least two bending-force-introducing portions (28), the tool element (21) has at least one elastic portion (30) via which the bending-force-introducing portions (28) are connected to one another.

2. Device according to Claim 1, characterized in that the tool element (21) has a contact portion (29) with respect to the pipe inner wall (101) that is provided between two outer bending-force-introducing portions (28).

3. Device according to Claim 2, characterized in that the contact portion (29) is movable via an actuator (20) or multiple actuators, in particular in a radial direction.

4. Device according to one of Claims 1 to 3, characterized in that the bending-force-introducing portions and / or contact portion (28, 29) are / is inherently elastically deformable and / or expand(s), and / or in that the elastic portion (30) is provided by at least one region with a material reduction in the tool element (21).

5. Device according to Claim 4, characterized in that the least one region with a material reduction in the tool element (21) is filled at least partially with an elastic material.

6. Device according to one of Claims 1 to 5, characterized in that at least one roller (42) is provided in the upper region of the main body (11) and / or of the tool.

7. Device according to Claim 6, characterized in that the at least one roller (42) is rigidly connected to the main body (11), and / or in that the at least one roller (42) extends through an opening (40) in the tool element (21), and / or in that the distance between the at least one roller (42) and the main body (11) is settable.

8. Device according to one of Claims 1 to 7, characterized in that the tool is at least partially slotted in its longitudinal direction so as to allow a slight elastic expansion in the radial direction.

9. Device according to one of Claims 1 to 8, characterized in that the main body (11) and / or the tool element (21) are of two-part construction.

10. Device according to one of Claims 1 to 9, characterized in that the tool element (21) is of multiple-part construction, wherein the tool element (21) is constructed from at least two bending-force-introducing-portion parts (60) and one contact-portion part (61), which are connected to one another.

11. Device according to Claim 10, characterized in that the contact-portion part consists of at least two bars (63), in that the bars (63) are connected to the at least two bending-force-introducing-portion parts (60), and in that at least two rib elements (64) are arranged on the bars (63).

12. Device according to Claim 11, characterized in that the rib elements (64) are of arcuate form and are seated on in each case one side (65) of the bars (63), and / or in that the ribs have a form fit with respect to the bending bar, and / or in that the at least two rib elements (64) have a spacing (66), resulting in a gap.

13. Device according to Claim 12, characterized in that at least one elastically deformable element (67) is provided in the gap.

14. Device according to one of Claims 10 to 13, characterized in that at least one actuator (20') is provided in the region of the contact-portion part (61).

15. Device according to Claim 14, characterized in that in each case at least one actuator (20') is arranged centrally below the at least two bars (63).

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