Forming machine, and method for producing complexly bent shaped parts
Patent Information
- Application Number
- EP2024708159
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-02-28
- Filing Date
- 2024-02-27
- Publication Date
- 2026-01-07
AI Technical Summary
Current forming machines struggle to produce complex curved parts with high dimensional accuracy, particularly in applications like electromobility where precise geometry is crucial for components like hairpins in electric motors, due to limitations in tool feeding directions and bending operations.
A forming machine with a system of forming units that allows for oblique tool feeding directions, including a second forming unit with a rotatable tool part and slewing gear for independent rotation, enabling complex bending geometries and increased flexibility in producing three-dimensionally curved parts by allowing bends at already bent points and varying feed directions.
This configuration enhances the accuracy and flexibility of producing complex bends, allowing for precise control over bending operations, which is critical for achieving the tight tolerances required in electromobility applications, such as hairpin production, by providing additional degrees of freedom in shaping and reducing shape deviations from target geometries.
Smart Images
Figure EP2024054896_06092024_PF_FP
Abstract
Description
[0001] Forming machine and method for producing complex bent molded parts
[0002] FIELD OF APPLICATION AND STATE OF THE ART
[0003] The invention relates to a forming machine and a method for producing shaped parts from an elongated workpiece, in particular for producing complex bent parts from wire.
[0004] Forming machines are computer-numerically controlled machine tools that, with the aid of suitable tools, can produce small or large series of molded parts, sometimes with complex geometries, from elongated semi-finished products such as wire, tube, strip, or the like in an automated manufacturing process, predominantly by forming. A complex-bent molded part is a molded part that has more than one bend, with bends located relatively close together and / or merging into one another and / or sometimes even lying in different planes. If such molded parts are manufactured predominantly or exclusively by bending operations, they are occasionally referred to in this application as bent parts.
[0005] There is a need for complex bent molded parts in the field of electromobility, among others. In this field, vehicles with fully or partially electric drive systems are increasingly being offered. Insulated and bent copper or aluminum bars, also known as "busbars," are used to electrically connect battery modules and / or as a replacement for cable harnesses. Since the installation spaces available for busbars are sometimes relatively tight and geometrically complex, busbars with bends in one or more places are often required. Wire materials in the form of insulated and bent copper or aluminum wires with an essentially rectangular or square cross-section are also frequently used to manufacture coil elements for the construction of stators for electric motors, so-called "hairpins."
[0006] Computer-numerically controlled forming machines are used today for the efficient production of large quantities of molded parts. When manufacturing molded parts from wire, the wire is conveyed or transported toward a forming system of the forming machine using suitable devices controlled by an NC control program. The forming system comprises several forming units, each carrying a forming tool that can be brought into engagement with the workpiece by an infeed movement or withdrawn after engagement. Under the control of the NC control program, different forming tools can be successively brought into engagement with the workpiece to successively create multiple bends and, thus, potentially complex bending geometries.
[0007] DE 10 2020 212 558 A1 discloses a bending machine for producing complexly bent parts from straight wire rods. The bending machine comprises a computer-numerical control unit, a transport system for transporting successive wire rods along a transport path, and a plurality of workstations arranged along the transport path. The transport system has a plurality of workpiece holding devices, each for holding a single wire rod. At least two of the workstations are designed as bending stations and equipped with numerically controlled bending units. The bending units each have a bending tool on their side facing the workpiece, which is selectively brought into engagement with or removed from the wire rod by means of a feed drive. The feed movements each run perpendicular to the course of the transport path in the region of the bending unit.Some of the bending units feed horizontally, others feed vertically.
[0008] DE 10 2019 213 976 A1 discloses a wire processing machine for producing straight or curved shaped parts from insulated flat material. The wire processing machine comprises, among other things, a feed device for feeding the flat material from a material supply and for conveying the flat material parallel to a through-feed axis, an integrated stripping device with two milling units for stripping sections of the insulated flat material, and a forming system. Twhich comprises a star-shaped arrangement with several forming units that can be fed essentially radially to the feed axis, with tool heads on which forming tools can be used to form the flat material by bending. The forming units are mounted on a vertical front wall and lie in a common plane oriented perpendicular to the transport direction of the wire.
[0009] The requirements for the geometry of the finished bent parts are sometimes extremely high. One example of this are the hairpins mentioned above, which are required for the assembly of stators for electric motors. The hairpins are plug-in coil elements in the form of lacquered copper wire clips with a complex, three-dimensional bent shape, which are intended to form essential parts of the stator windings. Since the component density in a stator should be as high as possible, there is only relatively little space available for a hairpin. Each hairpin must be integrated into its designated place. For this purpose, precisely dimensioned recesses are provided in the stator, into which a hairpin must fit precisely. In order to achieve high power densities, the sections of immediately adjacent hairpins lying outside the recesses should also be able to be located as close to one another as possible. For this reason, for example,For hairpins, strict specifications for the target geometry of the finished bent part.
[0010] There is therefore a need to find techniques that allow the production of complex bent parts with systematically small deviations from their target shape.
[0011] TASK AND SOLUTION
[0012] The invention is based on the object of providing a forming machine of the type mentioned in the introduction, with which complex bent shaped parts of a wide variety of geometries can be produced with high dimensional accuracy.
[0013] To achieve this object, the invention provides a forming machine having the features of claim 1. Furthermore, a method having the features of claim 13 is provided. Advantageous further developments are specified in the dependent claims. The wording of all claims is incorporated into the content of the description by reference.
[0014] According to one aspect of the invention, a forming machine for producing shaped parts from an elongated workpiece is provided. In a preferred application, the forming machine is suitable and intended for producing complexly bent parts from wire. The forming machine has a device for conveying an elongated workpiece to a forming system having a plurality of forming units. These can be controlled in a coordinated manner via a control device. Each of the forming units has a tool carrier having a tool holder for receiving a forming tool. The forming tool can be moved back and forth between a position retracted from the workpiece without engagement with the workpiece and an engagement position using a numerically controlled feed axis (machine axis for the feed) of the forming unit with an infeed movement of the tool carrier. The feed into the engagement position does not yet result in forming.In the engaged position, contact with the workpiece may already be present, but this is not mandatory. Starting from the engaged position, the workpiece can be formed by a working movement of the forming tool, for example by bending in a bending operation. The feed movement runs transversely to a local transport direction of the workpiece. The "local transport direction" of the workpiece is also referred to in this application as "transport direction" for short and describes the direction in which the workpiece is transported to the area of the respective forming unit. The transport can take place, for example, by feeding a workpiece in the form of continuous material into the area of the forming unit. It is also possible for the workpiece to be in the form of a bar cut to a certain length and to be transported to the forming unit, for example using a movable workpiece holding device.Then at least one section of the rod that has not yet been bent extends in the direction of transport.
[0015] The forming system comprises different types of forming units, namely at least one first forming unit and at least one second forming unit.
[0016] A first forming unit is characterized in that its tool carrier and the forming tool attached thereto can be advanced in a first feed direction, which lies in an orthogonal plane perpendicular to the local transport direction of the workpiece. The first feed direction can, for example, be oriented radially to the section of the workpiece to be formed, or possibly also tangentially to it.
[0017] In contrast, a second forming unit is characterized in that, in at least one working configuration of the second forming unit, its tool carrier and the forming tool attached thereto can be advanced in a second feed direction that is oblique to the local transport direction and oblique to the orthogonal plane. This second feed direction thus corresponds to an oblique direction that, in this working configuration, forms an acute angle with both the orthogonal plane and the local transport direction, i.e., an angle that lies between 0° and 90°.
[0018] This special design offers considerable advantages over conventional arrangements of forming units on similar forming machines, including the accuracy with which even complex bends can be created in the workpiece. The inventors' investigations have shown that although the conventional method of advancing forming tools perpendicular to the local transport direction is advantageous in many cases, with certain requirements regarding the shape or design of the bent part it can be more advantageous to advancing a forming tool at an angle to the local transport direction and to an orthogonal plane at at least one point, thereby bringing it into engagement with the workpiece material. This also makes it possible, among other things, to subsequently create a bend at a point that has already been bent.The second tool carrier has a tool holder for holding a forming tool in the form of a bending tool, which has at least one tool part rotatable about a bending axis. To enable the rotatable tool part to be rotated about the bending axis under NC control, the second forming unit has a rotary mechanism with a rotary drive for rotating the rotatable tool part about the bending axis. The bending axis is aligned parallel to the second feed direction. The bending axis thus runs parallel to the feed direction of the second forming unit.
[0019] This allows a wide variety of different bending geometries to be created. The infeed and the forming operation, or bending, are then two separate work movements. The actual forming can follow the linear infeed movement and is realized using at least one rotary movement.
[0020] Due to the possibility of inclining the second feed direction in combination with the simple spatial relationship (parallelism) between the orientation of the linear second feed direction on the one hand and the orientation of the bending axis on the other, even complex bending operations are relatively easy to program and can be carried out precisely on the workpiece.
[0021] The forming machine's configuration makes it ideally suited for producing three-dimensionally bent molded parts. If required, only two-dimensionally bent molded parts can also be produced. The proposed design provides greater degrees of freedom in forming compared to conventional forming machines, especially those of the type mentioned in the introduction, and certain limitations in forming can be avoided.
[0022] In many embodiments, several or all forming units, i.e. also one or more first forming units, are designed with a rotating mechanism corresponding to the second forming unit in order to be able to use a forming tool in the form of a bending tool with at least one tool part that can be rotated about a bending axis.
[0023] According to a further development, at least one of the forming units is designed to accommodate a forming tool in the form of a bending tool, which has two tool parts that can be rotated independently of one another about a bending axis, and the rotating mechanism has two independently controllable drives. This enables two independent rotations of tool parts of a accommodated bending tool. In many embodiments, several or all of the forming units, including one or more first forming units, are constructed in this manner.
[0024] According to a further development, a further contribution to the dimensional accuracy of the achievable bends is achieved by at least one forming unit having a machine axis designed to move the rotatable tool part toward a bending die, so that the received workpiece section can be clamped between the bending die and the tool part by means of the tool part. The workpiece can then be drawn around the bending die by rotating the tool part. The bending die can also rotate, enabling a rotary draw bending operation.
[0025] It is also possible that one or more first forming units can only be advanced linearly and the forming is achieved by continuing the linear movement of the tool carrier after reaching the workpiece contact in order to produce a bend.
[0026] A forming unit and the associated forming tool can also be designed for other forming operations that change the shape essentially without removing material, such as winding or coiling, or possibly also for pressing or embossing. Additionally, machining units can be provided for other machining operations, in particular material-removing operations such as punching, drilling, threading, milling, chamfering, and / or facing.
[0027] The second forming unit may be designed and installed in the forming system in such a way that the second feed direction permanently corresponds to a selected inclined direction that cannot be changed or cannot be changed without extensive assembly work. This inclined direction may, for example, be at a 45° angle to the transport direction and the orthogonal plane.
[0028] In other embodiments, however, a feed direction adjustment device is provided for variably adjusting the orientation of the second feed direction within a feed direction angle range. This allows different inclinations of the second forming unit relative to the local transport direction to be set, thereby increasing the flexibility in using the forming machine. Preferably, continuous adjustment is provided.
[0029] In particular, the feed direction angular range may include, in addition to one or more different oblique directions, at least one feed direction that lies in the aforementioned orthogonal plane. In this case, the second forming device can be fed in the same way as a first forming unit in corresponding working configurations. In some embodiments, the feed direction angular range is at least 180°. Thus, in some embodiments, it is possible to feed a second forming unit from two opposite directions perpendicular to the local transport direction, like a first forming unit, and additionally to optionally set an oblique direction as the feed direction.
[0030] In some embodiments, the feed direction adjustment device is designed for manual adjustment, so that the desired inclination of the second forming unit can only be set when setting up or converting the forming machine according to the desired target geometry of the molded part. In other embodiments, the feed direction adjustment device is a controllable machine axis, so that the inclination direction can be set and changed in response to control signals from the control unit by means of a dedicated drive, which is also possible during a sequence of bending operations on one and the same molded part, if necessary. In other words, during the production of a molded part, a second forming unit can, if necessary, be brought into engagement with the workpiece more than once and, if necessary, from different feed directions in order to introduce one or more bends at different points on the workpiece.
[0031] A preferably stepless adjustment of the second feed direction is realized in some embodiments in that the feed direction adjustment device has a curved guide on which a carriage is guided, which carries the second forming unit together with a drive of the feed axis for the second feed.
[0032] Alternatively or additionally, the second forming unit can be mounted on a rotary table, in particular such that the second forming unit can be pivoted about a rotation axis that runs perpendicular to the second feed direction. This further increases the flexibility of use.
[0033] It is possible that a single first forming unit is sufficient. In most embodiments, however, several, for example two, three, four or more first forming units are provided. This can increase the flexibility for producing different bending geometries. Different first forming units can be equipped with different forming tools; if necessary, several first forming units can also be equipped with the same type of forming tool. The first forming units can form a substantially coplanar arrangement in which several first feed directions or several first forming units, in particular all first feed directions or all first forming units, lie in a common orthogonal plane or in the vicinity thereof and the feed direction of the second forming unit is oriented obliquely to this orthogonal plane and to the transport direction.The individual forming units do not necessarily have to be arranged exactly in a single common plane. They can be arranged slightly offset in the transport direction and / or moved over short travel distances in the transport direction, while remaining close to the common orthogonal plane.
[0034] Some conventional torsion spring machines can be retrofitted with a second forming unit including associated drives and corresponding software components.
[0035] A further increase in the flexibility of the forming machine in the production of different three-dimensional bending geometries is achieved in preferred embodiments in that the devices for conveying the workpiece comprise a feed device for drawing in an elongated workpiece from a material supply and for conveying the workpiece to the forming system, wherein the feed device is preferably designed as a rotatable feed device for numerically controlled workpiece rotation. The feed device is thus designed as a rotatable feed device and has a rotary machine axis for numerically controlled workpiece rotation. The wire material can then be rotated with the aid of the feed device to change the orientation of the bending plane. The workpiece can then be rotated about the transport axis, for example, between the creation of a first bend and the creation of a second bend.
[0036] It is also possible for the first feed directions or first forming units to be located in different orthogonal planes offset from one another in the transport direction, and for the second forming unit to be arranged downstream of at least one first forming unit in the transport direction. This allows a subsequent bend to be created at an already bent location. In particular, a second forming unit can be arranged between an upstream and a downstream first forming unit.
[0037] Different forming tools can be used on the various forming units of the forming system depending on requirements, the workpiece material to be processed and the target geometry of the molded parts to be produced. The temporal sequence of their use is then specified via the control unit. A forming tool can be designed, for example, as a pin-and-mandrel tool with or without a rotating mandrel or as a rotary draw-bending tool. With a pin-and-mandrel tool, the mandrel does not usually rotate while the pin rotates around the bending axis during the bending operation. In rotary draw bending using a rotary draw-bending tool, the central bending mandrel and the rotatable tool part rotate synchronously during a bending operation, with the workpiece being clamped radially between the bending mandrel and the rotatable tool part.
[0038] A forming tool can also be designed as a winding tool or a coiling tool.
[0039] Preferably, at least one pin-mandrel tool and at least one rotary draw bending tool are used for a multi-stage bending sequence.
[0040] Accordingly, in some embodiments it is provided that at least one of the forming units, in particular a first forming unit, is configured as a rotary drawing bending unit.
[0041] In some embodiments, a fully configured forming machine has, on at least one forming unit, a multi-part forming tool comprising a bending die with a circumferential groove for receiving a portion of the workpiece to be bent and a tool part that can be rotated around the bending die by rotation about a bending axis for engaging a portion of the workpiece to be bent. The bending die is designed as a split bending die and has a lower die part and an upper die part that is movable relative to the lower die part. A lower boundary surface of the circumferential groove is formed on the lower die part, and an upper boundary surface of the circumferential groove is formed on the upper die part.To change the clear height of the circumferential groove, the upper and lower mold parts can be moved relative to one another by means of a drive between a closed configuration with a relatively smaller clear height and an open configuration with a comparatively larger clear height. To perform a bending operation, the forming tool is first moved into the open configuration and the workpiece is partially inserted into the circumferential groove so that a side of the workpiece facing the tool can be supported on the bending die. The forming tool is then moved into the closed configuration by means of the drive in such a way that the parts of the workpiece lying within the circumferential groove lie between the boundary surfaces of the circumferential groove without any play. This prevents the workpiece material from bulging in the area of the inner radius when the bend is created, thereby preventing it from deviating from the desired bending geometry.According to a further development, one of the molded parts, in particular the lower molded part, has a guide opening for axially guiding a displacement movement of the other molded part, while the other molded part, in particular the upper molded part, has a guide section dimensioned for insertion into the guide opening and a head section that is wider than the guide section, wherein a radial outer surface of the guide section delimits the circumferential groove inwardly and one of the boundary surfaces of the circumferential groove is formed on the head section. In this case, the guide section can have a cylindrical outer contour, at least on the side on which the flat material engages in the circumferential groove, such that the radially inner base surface of the circumferential groove is formed by the part of the radial outer surface of the guide section that is exposed between the upper and lower boundary surfaces.The mutual guidance of the molded parts makes the construction particularly simple and functionally reliable.
[0042] In some embodiments, the drive is controlled, at least during some bending operations, such that the section accommodated in the circumferential groove is clamped between the upper and lower boundary surfaces in the closed configuration with a clamping force acting substantially parallel to the bending axis. This allows for even better dimensional accuracy of the workpiece in the bending region.
[0043] Particularly when creating bends in flat material by bending over a narrower side of the flat material, it is considered advantageous if the boundary surfaces are aligned parallel to each other and perpendicular to a bending axis of the forming tool. This allows a flat bend without bulging to be achieved in a flat material, even when bending over a short side.
[0044] A forming machine according to the claimed invention can be used just like a conventional forming machine of the type mentioned in the introduction, given a corresponding number of first forming units. Additionally, methods for producing shaped parts are also possible in which at least one first bend is created in a first section of the workpiece by means of a first forming unit, wherein the first forming unit is advanced in a first feed direction perpendicular to the transport direction, and at least one second bend is created in a second section by means of a second forming unit, wherein the second forming unit is advanced in a second feed direction that is oblique to the transport direction and oblique to the orthogonal plane of the transport direction.To produce the second bend, a bending tool with at least one rotatable tool part is used, which is rotated about a bending axis oriented parallel to the second feed direction to produce the second bend.
[0045] This makes it possible to ensure that the first bend lies in a first bending plane containing the transport axis, and the second bend lies in a second bending plane oriented perpendicular to the second feed direction. The first and second bends can thus lie in different bending planes such that the molded part is a three-dimensionally bent part.
[0046] The at least one second bend can be created after a first bend. In particular, it can be the case that after the creation of a first bend, the workpiece has a section running in the transport direction and a section following the first bend, which section runs in a direction oblique to the transport direction, and that the second bend is created in this oblique section or in the region of the first bend. Due to the possibility of obliquely orientating the second feed direction, the process can be operated such that the second feed direction is oriented essentially perpendicular to the orientation of a workpiece section to be formed with the second forming unit. This means that the advantages of a feed directed orthogonally to a workpiece section can also be used if the section to be bent does not extend in the transport direction, but obliquely to it.This creates new degrees of freedom, including with regard to the sequence of bending operations in the production of complex bent molded parts.
[0047] Some processes are characterized by the fact that the second forming unit creates two bends with opposite curvatures in immediate succession, preferably without an intermediate straight section. This type of operation can be used, for example, to create the so-called S-bend in the production of hairpins.
[0048] It is also possible for the workpiece to be moved a distance in the transport direction between the creation of the first bend and the creation of the second bend. In particular, it may be the case that the workpiece is moved in a transport direction after the creation of the first bend and then, in a second section located at a distance from the first section, at least one second bend is created by means of a second forming unit. The second section is oriented in a direction transverse to the transport direction due to the first bend, and the second forming unit is fed in a feed direction that is oblique to the transport direction and oblique to a plane orthogonal to the transport direction.
[0049] In some embodiments, further degrees of freedom of design arise from the fact that the workpiece is rotated around the transport axis between the creation of a first bend and the creation of a second bend in order to change the bending plane.
[0050] In some embodiments, the forming machine comprises a forming system with a plurality of first forming units, whose first feed directions lie in a common orthogonal plane to the local transport direction or close to this common plane. In addition, at least one second forming unit is provided, in which the second feed direction is oriented obliquely to the orthogonal plane and the local transport direction. The workpiece is transported in the transport direction via a machine axis of the forming machine, referred to as the feed axis, with successive sections of the elongated workpiece material being successively conveyed into the region of the orthogonal plane.
[0051] In other embodiments, the forming machine is designed to produce complexly bent shaped parts from straight workpiece sections of a predetermined length. These can be straightened and separated from the supplied workpiece material in upstream operations before the first forming operation begins with a forming unit of the forming system. Such embodiments have a transport system for transporting successive straight workpiece sections (rods) along a transport path, wherein the transport system has a plurality of workpiece receiving devices, each for receiving an individual rod-shaped workpiece section. The forming system of this exemplary embodiment comprises a plurality of work stations arranged along the transport path, wherein at least two of the work stations are designed as bending stations in that at least one forming unit designed as a bending unit is arranged therein.The workpiece transport in the transport direction is realized here by a travel movement of the workpiece holding device along the transport route.
[0052] BRIEF DESCRIPTION OF THE DRAWINGS
[0053] Further advantages and aspects of the invention emerge from the claims and from the description of exemplary embodiments of the invention, which are explained below with reference to the figures. Fig. 1 shows an oblique perspective view of a forming machine designed in the manner of a torsion spring machine according to one exemplary embodiment;
[0054] Fig. 2A shows a part of the forming area of the forming machine from Fig. 1 from a different perspective;
[0055] Fig. 2B shows an oblique perspective view of a plug-in coil element;
[0056] Fig. 3 shows a schematic side view of a wire processing plant with a forming machine according to another embodiment;
[0057] Fig. 4 shows a bending station with a horizontally adjustable first forming unit;
[0058] Fig. 5 shows a bending station with a vertically adjustable first forming unit;
[0059] Fig. 6 shows a bending station with an inclined second forming unit;
[0060] Figs. 7A to 7F show different phases of a multi-step process for producing a hairpin in oblique perspective;
[0061] Fig. 8A to 8F show different phases of a multi-step process for producing a hairpin in plan view.
[0062] DETAILED DESCRIPTION OF THE EMBODIMENTS
[0063] Fig. 1 shows an oblique perspective view of a forming machine 100 designed like a leg spring machine according to one exemplary embodiment. Fig. 2 shows a part of the forming area of the forming machine from Fig. 1 from a side perspective during a phase of producing a hairpin.
[0064] The forming machine 100 is configured to produce complex, three-dimensionally bent molded parts in the form of coil elements for electric motors. A starting material (also referred to as workpiece W) is processed, which comprises a wire-shaped electrical conductor material (e.g., copper) with a substantially flat, rectangular, in particular square, cross-sectional shape, which is encased in an electrically non-conductive insulating layer of varnish or the like. The starting material is in the form of a wound material supply (coil). The workpiece is also referred to below as "wire" or "flat material" for short.The computer-numerically controlled, multi-axis forming machine 100 has a plurality of machine axes controllable via a control unit 190, a drive system with a plurality of electric drives for driving the machine axes, and a control device for the coordinated control of working movements of the machine axes in a manufacturing process according to a computer-readable control program specific to the manufacturing process.
[0065] In the exemplary embodiment, the forming machine has a rectangular machine coordinate system MK, designated by lowercase letters x, y, and z, with a vertical z-axis and horizontal x- and y-axes. The coordinate axes x, y, and z are to be distinguished from the controlled machine axes, whose drives are controlled via the control unit 190 of the forming machine.
[0066] The forming machine 100 comprises a machine frame having a vertically oriented front wall 105 at its front. The front-accessible forming system 200 of the forming machine comprises, among other things, a plurality of first forming units 220-1, 220-2, 220-3, and precisely one second forming unit 230.
[0067] Behind the front wall 105 are devices designed to convey the elongated, straightened workpiece material toward the forming system 200. These include a feed device 120 for drawing in the elongated workpiece material from a material supply and for advancing, conveying, or transporting the workpiece parallel to a transport axis 310 into the area of the forming system 200, as well as a straightening unit upstream of the feed device 120 for straightening the workpiece coming from the workpiece supply before it enters the feed device 120. The structure behind the front wall can correspond to the structure described in DE10 2019 213 976 A1. Reference is made to the corresponding disclosure.
[0068] In the example, the feed device 120 is designed as a belt feed device, but can also be designed as a roller feed device, a gripper feed device, or a caterpillar feed device. The feed device is designed to convey successive workpiece sections of the workpiece material coming from the material supply and straightened by the straightening unit with a numerically controlled feed rate profile in the horizontal transport direction 308 more or less coaxial with the transport axis 310, i.e., parallel to the x-axis of the machine coordinate system MK, through a downstream guide device 110 into the area of the forming system 200. The feed device 120 is rotatable by means of a servo-electric drive about a feed rotation axis corresponding to the transport axis 310 in both directions by predeterminable rotation angles (e.g., + / - 180°) (see curved double arrow).
[0069] The wire exits the guide device 110, which is equipped with a guide bushing, perpendicular to the front wall 105 and coaxial with the transport axis 310, into the area of the forming system 200. The guide bushing has a guide opening with a rectangular cross-section adapted to the rectangular cross-section of the flat material. The local transport direction 308 of the wire in the area of the forming units 220-x, 230 runs coaxially with the transport axis 310.
[0070] The wire is formed into a three-dimensionally bent part using numerically controlled tools of the forming system 200. The finished or largely finished formed part is then separated from the supplied wire with a scissor cut by a cutting unit 280. The cutting unit 280, equipped with a movable cutting blade, is positioned at a 45° angle to the vertical direction.
[0071] On the front wall 105, three first forming units 220-1, 220-2, 220-3 of the forming system 200 are mounted in a suitable orientation to the transport axis 310.
[0072] The single second forming unit 230 is mounted on an NC-controlled carriage 235, which can be moved over 180° on a semicircular curved guide 234 in a horizontal plane and can be fixed at various points along the curved guide. The carriage carries a rotary table 233, which is NC-controlled and motor-rotatable about a vertical axis of rotation, which in turn carries the second forming unit 230. These components belong to a feed direction adjustment device 270 for variably adjusting the orientation of the second feed direction within a feed direction angular range. This range is slightly more than 180° here and includes all oblique directions as well as an orientation parallel to the transport direction 308 and orientations of the second feed direction parallel to the orthogonal plane OE.
[0073] Each of the forming units has a tool holder for receiving a forming tool on its side facing the transport axis 310, wherein the forming tools here are generally one-piece bending tools or bending tools composed of several components.
[0074] Each forming unit has a translationally movable slide serving as a tool carrier, with which the respective forming tool can be selectively advanced into engagement with the workpiece or retracted in a linear or rectilinear advance movement along a feed direction. Furthermore, each forming unit has a rotary mechanism with one or more rotary drives to rotate movable components of the forming tool about a rotation axis (bending axis) 225 oriented parallel to the feed direction in response to control signals from the control device 190.
[0075] All first forming units are located near a common orthogonal plane OE (corresponding to a yz plane) oriented perpendicular to the transport axis 310. The associated first tool carriers 240-1, 240-2, 240-3 can each be fed in a first feed direction 222-1, 222-1, which lies in the orthogonal plane perpendicular to the local transport direction of the workpiece.
[0076] The second forming unit has a second tool carrier 242 which, in the illustrated working configuration, can be fed in a second feed direction 222-2 which is inclined at an acute angle W1 to the local transport direction 308 or 310 and at an acute angle W2 to the orthogonal plane OE (yz plane).
[0077] The first forming unit 220-1, visible on the right in Fig. 1 and on the left in Fig. 2A, is mounted on the front wall 105 with a horizontal slide axis for vertical displacement and can be advanced and retracted towards the workpiece using a feed drive in a first feed direction 222-1 running perpendicular to the transport axis and parallel to the orthogonal plane OE. The multi-part forming tool 250-1, mounted in a tool holder on the front of the workpiece carrier, is a pin-and-mandrel tool. It has a central bending mandrel with a diametrical groove that can be rotated about the horizontal bending axis and a bending pin that can be rotated around the bending mandrel independently of the bending mandrel. The bending tool can be used to create bends whose bending plane lies perpendicular to the rotational axis 225 of the bending tool or in the xz plane of the machine coordinate system.The position of the bending plane in relation to the transport axis can be specified by rotating the rotatable feed 120.
[0078] The diametrically opposite second forming unit 220-2 also has a first feed direction 222-1 in the y-direction, i.e., in the orthogonal plane OE. The forming tool attached to the front side of the tool carrier is also designed as a pin-and-mandrel tool, similar to the opposite side.
[0079] Above the transport axis, another first forming unit 220-3 is mounted horizontally on the front wall 105. Here, the slide axis or the feed direction 222-1 of the workpiece carrier runs vertically, i.e., parallel to the z-direction. The multi-part bending tool 250-3, mounted on the front of the tool carrier, engages the workpiece from above. It can produce flat bends in a horizontal bending plane.
[0080] The bending tool is specially adapted to bend a wire made of flat material around the short side, i.e. to create a flat bend in which the broad sides of the flat material in front of and behind the bend lie, if possible, in a common plane in which the flat material also lies in the area of the bend.
[0081] The forming tool 250-3 is designed as a rotary draw-bending tool. It comprises a central bending die 252, which can be rotated about the bending axis and has a circumferential, shallow groove 253 for receiving a section of the workpiece to be bent. Furthermore, a tool part 254 is provided, which can be rotated about the bending axis and the bending die. The rotatable tool part can be moved radially toward the bending die and in the opposite direction by means of its own machine axis. The flat material received in the circumferential groove can thus be held radially between this tool part and the bending die.
[0082] The bending die 252 is designed as a split bending die. It has a stationary die part 255, which is fixed relative to the tool holder, and an outer die part 256 with a widened head, which is movable relative to the stationary die part. One of the boundary surfaces of the circumferential groove is formed on the stationary die part, and the opposite boundary surface is formed on the movable die part. The movable die part 256 has a cylindrical guide section formed integrally with the head, which is guided for axial movement in a cylindrical guide opening of the stationary die part 255 and whose outer side forms the radially inner base of the circumferential groove.The clearance height of the circumferential groove can be continuously adjusted by using a drive to shift the movable mold part relative to the stationary mold part between a configuration with a relatively smaller clearance height and a configuration with a comparatively larger clearance height. A pneumatic drive has the advantage of force-controlled clamping and is thus independent of fluctuations in the wire dimensions. Clamping can also be implemented via a controlled machine axis, preferably with displacement control.
[0083] When performing a bending operation, the forming tool is first moved into the open configuration and the workpiece is partially inserted into the circumferential groove in such a way that a narrow side of the flat wire can rest against the bending die in the area of the groove base. The forming tool is then moved into a closed configuration so that the parts lying in the circumferential groove lie between the boundary surfaces of the circumferential groove without any play and are clamped with a clamping force acting parallel to the bending axis. This prevents the workpiece material from bulging in the area of the inner radius during bending and thus deviating from the desired bending geometry. The split bending tool is therefore used here to create a flat bend with a bending plane that corresponds to an xy plane.
[0084] The forming tool 250-2 on the horizontally adjustable tool carrier 242 of the second forming unit 230 is also constructed in several parts and has a central mandrel 251 with a diametrically continuous receiving channel for the workpiece and a tool part 253 with a bending pin that can be rotated around the mandrel.
[0085] By providing a second forming unit that can be advanced not in an orthogonal plane, but obliquely to this plane and the transport direction 308 or transport axis 310, new degrees of freedom arise in the design of bending geometries. Among other things, this makes it possible, after creating a bend in the workpiece, to introduce at least one further bend in the area of this bend. The second forming unit 230 can therefore act on a workpiece section that does not run parallel to the transport axis and may even already be bent. This allows completely new sequences of bending steps to be realized. It has been shown that, for example, in the production of hairpins, this can significantly improve the dimensional accuracy of the finished molded parts.
[0086] Fig. 2B illustrates a typical geometry of a multiply bent three-dimensional molded part FT or bent part in the form of a hairpin. The finished molded part essentially has the shape of a U-shaped bracket made of bent enameled copper wire and has two legs that should ideally run parallel to each other to allow the plug-in coil to be inserted into the designated space. The target geometry shown is characterized by a straight first section A1, which is connected via a complex curved section A3 to a second section A2, which according to the target geometry should run parallel to the first section A1. The broad sides of the flat material of the legs are usually at an angle to each other and are therefore not coplanar.In the roof-shaped section A3, which is occasionally referred to as roof section A3 due to its roof shape, a so-called S-bend S is formed in the area of the roof ridge. The S-bend is a sequence of directly merging bends with different curvature directions. The following example explains the sequence of bending steps that can be used to produce such a formed part using the forming machine shown in Fig. 1. Depending on the required geometry, a modified process may result.
[0087] First, a piece of flat material is advanced parallel to the transport axis 310. Then, the first forming unit 220-1 is brought into engagement with the still straight workpiece material by horizontal advancement radially to the transport axis, in order to subsequently create a slight inclination of the bent section with a small rotation.
[0088] The upper first forming unit 220-3 is then brought into engagement with the workpiece material by vertical infeed radially to the transport axis. The rotary draw bending movements create a first bend B1, which forms the transition between the first leg A1 and one side of the roof. Additionally, a slight torsion can be introduced by rotating the infeed.
[0089] In the following roof section, three small bends are then produced at short intervals and with the same direction of curvature using the horizontally adjustable first forming unit 220-1 in order to produce a slight curvature with a relatively large radius of curvature in this section.
[0090] The rotary draw-bend tool 250-3, coming from above, is then engaged again to create bend B2, which forms the roof ridge. In the area of this bend, the S-bend is now to be created by directly merging, opposing bends. This is where the advantage of the inclined second forming unit 230 comes into play. The bends to form the S-bend S are to be created in a tool section that does not run parallel to the transport axis 310, but rather at an angle to it. Because the second feed direction is also oriented at an angle to the transport axis 310 and the orthogonal plane, the pin-mandrel bending tool 250-2 of the second forming unit can be engaged from the side more or less perpendicular to the wire path. The two opposing partial curvatures of the S-bend can then be created by rotating the tool components forwards and backwards.
[0091] The bending operations already applied on the first side then follow in reverse order, first using the first forming tool to create the curves on the other side of the roof by means of three small bends. The rotary draw bending tool, which can be fed from above, is then engaged again to form the transition between the other side of the roof and the second leg, etc. Once all bends have been created, the cutting tool 280 is engaged to separate the finished shaped part in the form of a hairpin from the supplied wire material.
[0092] By rotating the feeder by a suitable angle, the workpiece is optimally turned or rotated for the engagement of the corresponding forming tool.
[0093] Alternatives to this structure and process are, of course, possible. For example, as an alternative to the first forming unit coming from above, a first forming unit coming from below can be provided on the opposite side. This can also be provided in addition to a first forming unit coming from above.
[0094] The structure and function of a second exemplary embodiment will now be explained with reference to Figs. 3 to 8. Fig. 3 shows a schematic side view of a wire processing system 400, which may be constructed identically or similarly in most parts to the wire processing system of the exemplary embodiment from the applicant's published application DE 10 2020 212 558 A1. Reference is made to the description therein.
[0095] The wire processing system is also designed to produce complex, three-dimensionally bent shaped parts in the form of hairpins from an insulated flat wire material. The starting material is in the form of a coiled material supply wound on a reel 504. The workpiece enters a rod assembly machine 410 with an integrated stripping device and passes successively through a straightening unit, a length measuring device, a milling device as part of a stripping device, a downstream brushing device, a downstream feed device, and a downstream cutting device. Regarding the design and function of the rod assembly machine, reference is made to the above-mentioned patent application.
[0096] The rod assembly machine 410 delivers elongated workpieces W in the form of straightened wire rods of a predefined length as an intermediate product, which are cut from the supplied wire. The wire rods are transported to a downstream forming machine in the form of a bending machine 500 by means of a rod transfer device. The longitudinal direction (direction of the longitudinal center axis) of the wire rods runs horizontally and parallel to the transport direction of the wire rods.
[0097] The bending machine 500 has its own base 505, to the top of which components of a transport system 510 are mounted for transporting successive wire rods along a transport path 512. The transport path runs in a horizontal plane (xy plane). For illustrative purposes, the transport path is shown in Fig. 3 in the area of the base 505 in a schematic plan view of the transport plane. The transport path 512 is closed in the circumferential direction and has a substantially rectangular shape with straight longitudinal and transverse sides and curved sections in the corner areas.
[0098] The transport system 510 comprises a plurality of individual transport units 515, for example, from three to ten or more transport units. Each transport unit has a workpiece receiving device 525 for receiving a single wire rod W. This wire rod W runs in the region of the workpiece receiving device coaxially to its receiving axis and horizontally and parallel to a direction that corresponds to the local transport direction on the transport path.
[0099] Each movement of a transport unit 515 can be performed according to an individual movement profile, which can be specified by the control unit based on a computer program. The transport units 515 are moved via linear direct drives.
[0100] In the example, the bending machine 500 has several bending stations 550-1, 550-2, etc. arranged one after the other along the transport path. At each of the bending stations, a forming unit is attached, with which a bending operation can be carried out on the wire rod, or possibly even several bending operations.
[0101] Fig. 4 shows a perspective side view of the first bending station 550-1. It has a first forming unit 520-1, which can be positioned parallel to the transport path and in the vertical direction using suitable drives. The forming unit has a tool holder for holding a forming tool on its side facing the transport axis. In the example case, this is a multi-part forming tool in the form of a pin-mandrel tool, the rotatable components of which can be rotated about a horizontal axis of rotation. The infeed movement runs in an orthogonal plane OE parallel to a horizontal infeed direction that is oriented perpendicular to the transport direction. With the help of the infeed drive, the forming tool can be brought into engagement with the workpiece in order to then create a bend in the flat material through a rotary working movement.
[0102] Fig. 5 shows a schematic side view of a second bending station 550-2 with a forming unit 520-2 that can be positioned horizontally (parallel to the transport axis). Just like the forming unit of the first bending station, the first forming unit 520-2 can be linearly advanced in an orthogonal plane OE oriented perpendicular to the transport direction. The associated advance direction can be vertical or at an acute angle to the vertical. The ability to change the advance direction within the orthogonal plane OE oriented perpendicular to the transport direction is enabled by a curved guide at the base of the bending station. The forming tool of this forming unit corresponds to the forming tool 250-3 with a split bending die, which was explained in connection with Fig. 2 by other embodiments.At this bending station, the wire can be bent by means of rotary draw bending, whereby the bending point can remain clamped in the split bending mold and bulges are thus prevented, so that even when bending over the short side of the flat material, no bulges arise from the bending plane.
[0103] Fig. 6 shows a variant of a second forming unit 530, which is also mounted along the transport path, for example in a third bending station 550-3 between the second bending station 550-2 and a subsequent fourth bending station.
[0104] The second forming unit 530 is shown in a working position in which the horizontal feed direction of the tool carrier is neither parallel to the transport direction 508 nor in an orthogonal plane (plane perpendicular to the transport direction). Instead, the second forming unit has a second tool carrier which, in the working configuration shown and other working configurations of the second forming unit, can be fed in a second feed direction 522 which is oblique to the local transport direction 508 and oblique to an orthogonal plane. The angle of incidence W2 between the feed direction and the transport direction 508 is continuously adjustable. For this purpose, the base plate 521, which supports the forming unit, is mounted on a turntable 522, which in turn is mounted on a carriage 523 which can be moved parallel to the transport direction.The available feed direction angle range extends over more than 90° in a horizontal plane, so that the second forming unit 530 can also be used as a first forming unit by adjusting the feed direction by rotating the turntable so that it is oriented radially to the transport axis of the wire rod.
[0105] With this forming machine, too, a particularly efficient bending process for producing hairpins with particularly high dimensional accuracy is possible by using at least one second forming unit 530 with the option of inclined feed.
[0106] 7A to 7F show, by way of example, a schematic bending sequence for producing a hairpin using a forming machine similar to Fig. 3, wherein the bending units of the first and second bending stations are interchanged. Since the sequence of images is self-explanatory, only brief details of particularly noteworthy aspects will be given. In the straight wire rod W, a first larger bend is first created using the vertically adjustable forming unit (Fig. 7A), before slight bends are created using a horizontally adjustable forming unit, opening up the third dimension (Fig. 7B). A vertically adjustable rotary draw bending unit is then brought into engagement again to create the bend at the roof ridge (Fig. 7C). At the next bending station (Fig. 7D) there is then a second forming unit, i.e. a forming unit whose bending tool can be advanced in an inclined direction to the transport direction and to the orthogonal plane.The forming tool, designed as a pin-and-mandrel bending tool, then creates the so-called S-bend in the prefabricated bend by alternating engagement and alternating rotation in opposite directions. Here, too, the inclined infeed allows for optimal tool engagement, resulting in optimal tool geometry. The next bending operations are then performed sequentially at two subsequent bending stations. The bend shown in Fig. 7E is created in a vertical bending plane, while the final bend shown in Fig. 7F is created with the rotary draw bending tool that can be fed from above.
[0107] Figs. 8A to 8G show a corresponding sequence of bending operations in a schematic plan view. After the first bend with a horizontal bending plane (Fig. 8A), a curved roof side is created by three small bends in a vertical bending plane (Fig. 8B), before the bend that will form the roof ridge is created in a subsequent bending operation in a horizontal bending plane (Fig. 8C). The second forming unit then comes into action, which is advanced obliquely to the transport direction and to the orthogonal plane. Fig. 8D shows the first bending operation in a bending plane oriented vertically and obliquely to the transport direction. Fig. 8E shows the subsequent bending operations, which create a bend with the opposite direction of curvature slightly offset from the first bend to form the S-bend. Figs. 8F and 8G then show the final bending operations leading to the finished hairpin (Fig. 8G).
Claims
Patent claims 1. A forming machine (100) for producing shaped parts from an elongated workpiece, in particular for producing complexly bent wire parts, comprising: means for conveying an elongated workpiece (W) to a forming system (200) having a plurality of forming units (220-x, 520-x), each of the forming units having a tool carrier (240-x, 242) having a tool holder for receiving a forming tool (250-x, 550-x), which is movable back and forth between a position retracted from the workpiece (W) and an engagement position by means of a numerically controlled feed axis of the forming unit via a feed movement of the tool carrier directed transversely to a local transport direction of the workpiece; characterized in that the forming system (200) comprises at least one first forming unit and at least one second forming unit,wherein the first forming unit (220-x) has a first tool carrier (240-x) that can be fed in a first feed direction (222-1) that lies in an orthogonal plane (OE) perpendicular to the local transport direction (308) of the workpiece, and the second forming unit (230) has a second tool carrier (242) that can be fed in at least one working configuration of the second forming unit in a second feed direction (222-2) that lies obliquely to the local transport direction (308) and obliquely to the orthogonal plane (OE), wherein the second tool carrier (242) has a tool holder for receiving a forming tool (250-2) in the form of a bending tool, which has at least one tool part (253) that can be rotated about a bending axis (225), and the second forming unit has a rotary mechanism with a rotary drive for rotating the rotatable tool part about the bending axis (225),wherein the bending axis (225) is aligned parallel to the second feed direction (222-2)., 2. Forming machine according to claim 1, characterized in that several or all forming units (220-x, 520-x) have a rotating mechanism for operating a forming tool in the form of a bending tool with at least one tool part rotatable about a bending axis and / or that at least one of the forming units is designed to receive a forming tool in the form of a bending tool which has two tool parts rotatable independently of one another about a bending axis and that the rotating mechanism has two independently controllable rotary drives for rotating the rotatable tool parts.
3. Forming machine according to claim 1 or 2, characterized in that at least one forming unit, in particular a first forming unit (220-3), is configured as a rotary draw-bending unit and for this purpose has a machine axis which is designed to move the rotatable tool part in the direction of a bending mold (252) so that a received workpiece section can be clamped by means of the tool part between the bending mold and the tool part.
4. Forming machine according to claim 1, 2 or 3, characterized by a feed direction adjustment device (270) for variably adjusting the orientation of the second feed direction (222-2) within a feed direction angular range, wherein the feed direction angular range preferably comprises, in addition to an oblique direction, at least one feed direction which lies in an orthogonal plane (OE) perpendicular to the local transport direction (308) and / or wherein the feed direction angular range is at least 180°.
5. Forming machine according to claim 4, characterized in that the feed direction adjustment device has a controllable machine axis for changing the second feed direction (222-2), wherein the feed direction adjustment device preferably comprises a curved guide (234) on which a carriage (235) is guided, which carries the second forming unit (230) together with a drive of the feed axis and / or wherein the second forming unit (230) is mounted on a turntable (233), in particular in such a way that the second forming unit (230) is pivotable about a rotation axis (231) which runs perpendicular to the second feed direction (222-2).
6. Forming machine according to one of the preceding claims, characterized in that the forming machine has a plurality of first forming units (220-1, 220-2, 220-3), in particular two, three, four or more first forming units, 7. Forming machine according to claim 6, characterized in that several first forming units (220-1, 220-2, 220-3) with differently oriented first feed directions (222-1) are arranged in or near a common orthogonal plane (OE) and the second feed direction (222-2) of the second forming unit (230) is oriented obliquely to this orthogonal plane (OE) and to the transport direction (308) 8. Forming machine according to one of the preceding claims, characterized in that the means for conveying the workpiece comprise a feed device (120) for drawing in an elongated workpiece (W) from a material supply and for conveying the workpiece to the forming system (200), wherein preferably the feed device is designed as a rotatable feed device (120) for numerically controlled workpiece rotation.
9. Forming machine according to claim 6, characterized in that a plurality of first forming units (520-1, 520-2) are arranged in different orthogonal planes (OE) offset from one another in the transport direction and the second forming unit (530) is arranged downstream of at least one first forming unit in the transport direction (308), wherein preferably a second forming unit (530) is arranged between an upstream and a downstream first forming unit.
10. Forming machine according to one of the preceding claims, characterized in that at least one forming unit has a multi-part forming tool (250-3) which has a bending mold (252) with a circumferential groove (253) for receiving a section of the workpiece (W) to be bent and a tool part (254) which can be rotated about the bending mold by rotation about a bending axis (225) for engaging a section of the workpiece to be bent.
11. Forming machine according to claim 10, characterized in that the bending mold (252) is designed as a split bending mold which has a lower mold part and an upper mold part which is movable relative to the lower mold part, wherein a lower boundary surface of the circumferential groove is formed on the lower mold part and an upper boundary surface of the circumferential groove is formed on the upper mold part, and the upper mold part and the lower mold part are displaceable relative to one another by means of a drive between a closed configuration with a relatively smaller clear height and an open configuration with a larger clear height compared to the smaller clear height in order to change the clear height of the circumferential groove (253), wherein the boundary surfaces are preferably aligned parallel to one another and perpendicular to a bending axis (225) of the forming tool (250-3).
12. Forming machine according to claim 11, characterized in that the drive is designed such that the section accommodated in the circumferential groove (253) is clamped in the closed configuration with a clamping force acting parallel to the bending axis (225) between the upper and the lower boundary surface and / or that one of the mold parts has a guide opening for axially guiding a displacement movement of the other mold part, and the other mold part has a guide section dimensioned for insertion into the guide opening and a head section widened compared to the guide section, wherein a radial outer surface of the guide section delimits the circumferential groove inwards and one of the boundary surfaces of the circumferential groove is formed on the head section wherein the guide section preferably has a cylindrical outer contour at least on the side on which the engagement of the flat material in the circumferential groove takes place, such that a radially inner base surface of the circumferential groove is formed by a part of the radial outer surface of the guide section which is exposed between the upper and lower boundary surfaces.
13. A method for producing shaped parts from an elongated workpiece, in particular for producing complexly bent bent parts from wire, wherein the elongated workpiece is conveyed towards a forming system having a plurality of forming units, each carrying a forming tool which can be moved, via a feed movement running transversely to a local transport direction of the workpiece, either into a working position engaging with the workpiece or into a retracted position; wherein at least one first bend is produced in a first section of the workpiece by means of a first forming unit, wherein the first forming unit is fed in a first feed direction running perpendicular to the transport direction;in a second section, at least one second bend is produced by means of a second forming unit, wherein the second forming unit is fed in a second feed direction which is oblique to the transport direction and oblique to an orthogonal plane of the transport direction, and a bending tool with at least one rotatable tool part is used to produce the second bend, which is rotated about a bending axis oriented parallel to the second feed direction to produce the second bend; 14. Method according to claim 13, characterized in that at least a second bend is produced temporally after a first bend.
15. Method according to claim 13 or 14, characterized in that the first bend is produced by means of rotary draw bending.
16. Method according to claim 13, 14 or 15, characterized in that after the creation of a first bend, the workpiece has a section running in the transport direction and a section following the first bend which runs in a direction oblique to the transport direction and that the second bend is created in the oblique section or in the region of the first bend.
17. Method according to one of claims 13 to 16, characterized in that the second feed direction is oriented substantially perpendicular to the orientation of a workpiece section to be formed with the second forming unit.
18. Method according to one of claims 13 to 17, characterized in that two bends with opposite curvature directions are produced in immediate succession with the second forming unit.
19. Method according to one of claims 13 to 18, characterized in that the workpiece is moved in a transport direction after the production of the first bend and then at least one second bend is produced in a second section located at a distance from the first section by means of a second forming unit, wherein the second section is oriented in a direction running transversely to the transport direction due to the first bend and the second forming unit is fed in a feed direction which is oblique to the transport direction and oblique to an orthogonal plane of the transport direction.
20. Method according to one of claims 13 to 19, characterized in that the workpiece is rotated about the transport axis between the production of a first bend and the production of a second bend in order to change the bending plane.
21. A forming machine for producing shaped parts from an elongated workpiece, in particular for producing complex bent parts from wire, comprising: a feed device (120) for feeding an elongated workpiece (W) from a material supply and for conveying the workpiece along a transport axis (310) to a forming system (200), wherein the feed device is designed as a rotatable feed device (120) for numerically controlled workpiece rotation about the transport axis (310);and the forming system (200), which has at least one forming unit (230) having a tool carrier (242) with a tool holder for receiving a forming tool (250-2), which is movable back and forth between a position retracted from the workpiece (W) and an engaged position by means of a numerically controlled feed axis of the forming unit via a feed movement of the tool carrier directed transversely to a local transport direction of the workpiece; characterized in that the tool carrier (242), in at least one working configuration of the forming unit (230), is feedable in a feed direction (222-2) that lies obliquely to the local transport direction (308) and obliquely to an orthogonal plane (OE) that lies perpendicular to the local transport direction (308) of the workpiece, and in that; a feed direction adjustment device (270) is provided for variably adjusting the orientation of the feed direction (222-2) within a feed direction angular range which, in addition to the feed direction (222-2) oriented obliquely to the local transport direction (308) and obliquely to the orthogonal plane (OE), comprises at least one feed direction which lies in the orthogonal plane (OE).
22. Forming machine according to claim 21, characterized in that the feed direction angular range is at least 180°.
23. Forming machine according to claim 21 or 22, characterized in that the feed direction adjustment device has a controllable machine axis for changing the second feed direction (222-2), wherein the feed direction adjustment device preferably comprises a curved guide (234) on which a carriage (235) is guided, which carries the second forming unit (230) together with a drive of the feed axis 24. Forming machine according to claim 21, 22 or 23, characterized in that the second forming unit (230) is mounted on a rotary table (233), in particular such that the second forming unit (230) is pivotable about an axis of rotation (231) which runs perpendicular to the feed direction (222-2).