Forming machine comprising a plurality of workstations

Abstract

A numerically controlled forming machine (100) for producing complexly shaped formed parts from straight workpieces (WS) comprises a plurality of workstations, which comprise a loading station (400) and at least two processing stations (410, 420) connected downstream thereof, as well as a machine frame for mounting tool-carrying work units to form workstations. A transport system (500) for transporting successive workpieces (WS) from the loading station (400) to downstream workstations under the control of the control unit has a plurality of transport units (520), each of which has a gripping unit (560) for gripping a workpiece and is able to move back and forth in pendulum operation between two end positions (522-1, 522-2) of a pendulum stroke, each of which is assigned to a workstation, under the control of the control unit (190). The forming machine comprises components of a coordinate alignment system for aligning coordinates between a transport coordinate system (TKS), assigned to a transport unit, and a tool coordinate system (WKS) assigned to a respective workstation, in order to determine coordinate transformation data. The control unit is configured to control a transport unit using the coordinate transformation data in such a way that a gripping unit (560) of the transport unit can be controlled with positional accuracy to a target position that can be specified in the tool coordinate system.

Description

[0001] Forming machine with multiple workstations

[0002] FIELD OF APPLICATION AND STATE OF THE ART

[0003] The invention relates to a forming machine for producing complex shaped parts from straight workpieces made of wire or tube under the control of a computer numerical control unit according to the preamble of claim 1 and to a method for setting up such a forming machine.

[0004] A computer-numerically controlled forming machine of the type considered here has several workstations. The workstations include a loading station, via which the forming machine can be loaded with the usually straight workpieces to be processed, as well as a first processing station downstream of the loading station and at least one second processing station downstream of this first processing station. A processing station is a workstation in which the workpiece is processed and thereby its properties, in particular with regard to its shape or design, are changed. At least two of the processing stations are designed as forming stations, where the workpiece is formed, e.g., by bending or pressing. The forming machine performs several forming operations under the control of the control unit; additional processing operations, e.g., machining, can also be provided.

[0005] The workpieces to be processed pass through the workstations successively. For this purpose, the forming machine is equipped with a transport system for transporting successive workpieces from the loading station to downstream workstations. The transport system operates under the control of the control unit. Such multi-station forming machines are typically used when large quantities of possibly complex molded parts need to be produced in a short time.

[0006] A shaped part within the meaning of this application is an intermediate or final product, usually consisting predominantly or exclusively of metal, which is manufactured from a blank, wherein the original shape or form of the blank is deliberately changed by machining during the manufacturing process. The machining comprises forming operations that change the shape essentially without removing material, such as bending, pressing or embossing. In addition, other machining operations can be provided, in particular material-removing operations such as punching, drilling, threading, milling, chamfering and / or facing. The document US 2005 / 145003A1 describes a computer-numerically controlled bending system with a series of bending stations, each equipped with a bending head. The workpieces are transported from one bending station to the next using grippers.The grippers are suspended from a two-axis gantry and preferably grip the workpiece in a central area. Each bending head grips the tube at a different intermediate position. In the preferred embodiment, each bending station is capable of positioning the bending head so that the free end of the workpiece to be bent can be aligned in the bending plane without interference from an adjacent bending station.

[0007] Schmale Maschinenbau GmbH offers a purely servo-electric wire bending machine called the "X2000NC." Thanks to its modular design with a work wall and mountable work units, it allows for variable configuration with a wide variety of units to implement even complex forming processes (https: / / www.schmale-gmbh.de / maschinen / x2000nc.html). With bending slides, punching, upsetting, and embossing presses, many required forming processes can be implemented. A linear transfer is provided for transporting workpieces from workstation to workstation, serving the various forming stations simultaneously and is therefore significantly faster than conventional CNC wire bending machines.

[0008] There is still a need for forming machines that can operate with high unit output on the one hand and, on the other hand, offer the user great flexibility with regard to the multi-stage processes that can be implemented with them.

[0009] TASK AND SOLUTION

[0010] Against this background, the object of the invention is to provide a forming machine of the type mentioned in the introduction, which is capable of producing complex shaped parts of high quality at a high unit output and, on the other hand, offers the user high flexibility with regard to the realization of different multi-stage forming processes at low costs.

[0011] To achieve this object, the invention provides a forming machine having the features of claim 1. Furthermore, a method for setting up such a forming machine having the features of claim 9 is provided. Advantageous developments are specified in the dependent claims. The wording of all claims is incorporated into the description by reference. According to one formulation of the invention, a forming machine is provided for producing complexly shaped shaped parts from straight workpieces. The workpieces can consist of wire or tube. The production process is controlled by a computer numerical control unit of the forming machine. The forming machine has several workstations. These include a loading station, a first processing station downstream of the loading station in the direction of workpiece flow, and at least one second processing station downstream of the first processing station.Machining stations are workstations where the workpiece can be processed. The processing can include one or more forming operations. Forming can be achieved, for example, by bending or pressing. This allows the originally straight workpiece to be reshaped or otherwise altered in its shape or other properties using several consecutive processing steps.

[0012] The forming machine has a machine frame with mounting structures for assembling tool-carrying work units that can be mounted on the machine frame to form work stations. The fully operational forming machine also has a transport system for transporting successive workpieces from the loading station to the downstream work stations under the control of the control unit. The transport system comprises several transport units. A transport unit has a gripper unit for gripping a workpiece and can be moved back and forth between a first end position and a second end position of a pendulum stroke under the control of the control unit. The first end position is assigned to one of the work stations, and the second end position to another work station downstream of this.

[0013] According to the claimed invention, the forming machine comprises components of a coordinate alignment system for aligning coordinates between a transport coordinate system assigned to a transport unit and a tool coordinate system assigned to a respective workstation to determine coordinate transformation data. The control unit is configured to control movements of a transport unit using the coordinate transformation data such that the gripping unit of the transport unit can be precisely controlled to a target position specified in the tool coordinate system.

[0014] The target position can, for example, be an insertion position or deposit position to which the gripping unit holding the workpiece must be moved so that the tools of the associated workstations can process or further process the workpiece. A target position can also correspond to a pick-up position. This is understood to be the position to which the gripping unit must be moved in order to grip the workpiece machined at the workstation after the end of at least one machining operation and thus pick it up so that it can be transported to a subsequent workstation. The pick-up position can correspond to the insertion position, i.e. have the same coordinates. Often, however, the coordinates of the insertion position and the pick-up position differ, so that the workpiece is held in a different place during transport to the work unit than for transport away.

[0015] With a forming machine equipped in this way, the forming machine can be set up for subsequent productive operation much faster than before, with high precision. It is not necessary to have the setup work performed by experienced, trained personnel, as the coordinate alignment system supports the setup work.

[0016] According to another aspect, the invention relates to a method for setting up a forming machine of the type mentioned above. A machine frame is provided having mounting structures for mounting tool-carrying work units to form work stations. The mounting structures are preferably flexible in use, so that available mounting positions are not fixed in all directions by stops or the like. By mounting work units at mounting positions on the machine frame, several work stations are formed, which comprise a loading station, a first processing station downstream of the loading station, and at least one second processing station downstream of the first processing station. Furthermore, components of a transport system of the type mentioned above are mounted using corresponding transport units.To set up the forming machine before productive operation, a setup operation is carried out. This includes a coordinate comparison operation in which coordinates are compared between a transport coordinate system assigned to a transport unit and a tool coordinate system assigned to a respective workstation. From this comparison, coordinate transformation data is determined, processed, and saved. During production, the movements of a transport unit are then controlled using the coordinate transformation data in such a way that a gripping unit of a transport unit can be precisely controlled to a target position specified in the tool coordinate system. The position of the respective gripping unit in the transport coordinate system is known. This can be used when attaching the gripper unit to the component that supports it, for example.be predetermined by the geometry of the assembly structures and may be determined by re-measuring during setup and taken into account during coordinate alignment.

[0017] The target position can be specified, for example, as the position that the gripping unit is to reach when transporting a workpiece and / or the position at which the gripping unit is to be positioned in order to grip the workpiece after completion of the operation to be carried out at a work station and then transport it further.

[0018] The claimed invention offers particularly great advantages in cases in which flexibly usable mounting structures are provided on the machine frame, which in principle make it possible to freely select the working units of the various workstations relative to the machine frame and also relative to each other within certain limits.

[0019] For example, the forming machine may comprise a machine frame with a mounting wall that has flexibly usable mounting structures on a front side with a plurality of mounting grooves and / or mounting holes for mounting work units to form the workstations. The mounting wall may be modular in design, for example, allowing the mounting wall to be expanded as needed by adding one or more mounting wall modules.

[0020] The mounting structures may comprise a plurality of mounting grooves arranged at a distance one above the other and oriented parallel to the transport direction, which are designed such that work units and / or other components can be mounted at any position along the mounting grooves.

[0021] Flexible assembly structures are advantageous, among other things, in terms of optimal space utilization, but they pose the problem that an assembled work unit is not automatically located in a position known to the control unit after assembly. Some variants do not have a defined zero point on the machine frame to which control commands can later refer. This could lead to incorrect positioning when delivering or picking up workpieces.

[0022] With the help of the coordinate alignment system, it is now possible to set up the forming machine with relatively little time and effort so that the transport unit or its grippers can move precisely to their respective target positions in every process phase. This increases the operational reliability of the forming machine and also contributes to the production of workpieces with high dimensional accuracy.

[0023] According to a further development, the coordinate alignment system is configured for automatic alignment between the transport coordinate system and the tool coordinate system. This means, among other things, that after the work units have been mounted on the machine frame and, if necessary, after attaching temporarily usable components of the coordinate alignment system, key steps of the coordinate alignment operation can be performed automatically or without operator intervention. Such (fully) automatic coordinate alignment offers significant time savings compared to purely manual or semi-automatic coordinate alignment, without any loss of the achieved precision of the setup.Semi-automatic setup can be performed by moving a transport unit "manually" to a reference point at a workstation. As it approaches this point, it slows down and then, for example, passes over this point once to the left and once to the right. This is how teaching takes place. The taught points can then be used in the machine's control system. The transmission of the coordinate transformation data and the receipt of information about the target position are then usually automatic.

[0024] To create a workstation, it is possible to mount one or more work units of the workstation directly at corresponding mounting positions on the machine frame. During setup, the work units mounted on the machine frame would then have to be more precisely adjusted relative to the machine frame and, if necessary, relative to each other. This can make it take a relatively long time until the forming machine is assembled and set up for a new process.

[0025] According to a further development, however, it is provided that at least one of the workstations has a tool module mounted or mountable on the machine frame, which comprises a base support mounted or mountable on the machine frame and which supports two or more, in particular all, work units of the workstation. In this case, all work units that may carry tools can be aligned with reference to a common reference point in a support-fixed or module-fixed tool coordinate system. This embodiment can be provided for a single workstation, for several of the workstations, or even for all workstations. During the assembly of the forming machine and the setup work, the procedure can then be such that one or more tool modules are first pre-assembled away from the machine frame.A tool module comprises a base support that can be mounted on the machine frame, which is then equipped with and supports one or more work units. All tool-carrying work units of a tool module are then aligned with reference to a reference point in the support-fixed or module-fixed tool coordinate system. The pre-assembled tool module is then mounted in a suitable position on the machine frame. Since all work units (one or more) within the tool module are already aligned with reference to a common reference point, all that needs to be done when setting up the forming machine is to ensure that the position of the tool module is determined and that data representing this position is made available to the control unit during coordinate alignment. Only the position of the reference point is required for coordinate alignment.

[0026] Starting from the reference point, certain points of interest on a work unit or tool module can be dimensioned. The reference point can, in principle, be located anywhere on a tool, work unit, or base support. The location can be chosen based on practical considerations. The specific points mentioned here could, for example, be the deposit position and pick-up position of the gripping unit of the transport unit.

[0027] It is possible to establish the relationship between the tool coordinate system and the transport coordinate system by directly determining the position of the reference point in the transport coordinate system. However, the reference point is often a virtual point whose position does not necessarily have to be visible or marked. For the practical implementation of coordinate alignment, preferred embodiments provide for a work unit or a tool module to have an optically, mechanically, or otherwise tangible auxiliary structure that defines an auxiliary zero point that has an offset relative to the reference point that can be described using offset data, and for the coordinate alignment system to have a device for storing the offset data or data derived therefrom.

[0028] The auxiliary structure can, for example, comprise a visually visible marking (e.g., a glass scale) attached to a work unit, a tool, or a tool module in a clearly visible location and can be contacted during setup using a non-contact (e.g., optical) or tactile method. If necessary, selected edges of the base support, a defined bore in the base support that can be contacted using a measuring probe, or other contactable contours on the tool module can also be used as an auxiliary structure.

[0029] The offset can be determined, for example, when setting up the tool module components; the offset data will be needed later for coordinate alignment. The auxiliary zero point and the reference point can coincide (so that the offset is then zero); typically, the reference point and auxiliary zero point are spaced apart.

[0030] According to a further development, the coordinate alignment system comprises at least one probing device for probing the auxiliary structure, which is mounted or can be mounted in the correct position on a transport module and, in the mounted state, is movable with the transport unit. This probing device can be attached or formed on a work unit or a part of the tool module. The probing then enables a link between the coordinate systems (of the transport unit and the tool side). The probing device can be used only during setup mode and removed again before the start of productive operation. However, the probing device can also be permanently mounted on the transport unit and, if necessary, also used during productive operation.

[0031] A probing device can operate tactilely and, for example, have at least one measuring tip and associated sensors. There are also non-contact probing devices that operate according to an optical principle, for example. This can involve a measuring camera and / or a laser system, e.g., with a laser pointer.

[0032] There are several options for storing offset data for later use during coordinate alignment. In some embodiments, the tool module or a work unit has a preferably automatically readable data carrier containing the offset data or access data for accessing the offset data. The offset data can be stored, for example, in a data storage device accessible to the control unit of the forming machine. In this case, it may be sufficient to provide a corresponding identification of the tool module or work unit on the tool module or a work unit in order to enable access to the associated stored offset data.

[0033] If a transport unit has a read-out device that can be moved with the transport unit at least during a setup operation for reading out data contained in the data carrier, the read-out operation can possibly take place simultaneously with the probing operation without the need for an operator to intervene.

[0034] The claimed invention can be advantageously applied to differently constructed forming machines. In a particularly preferred embodiment, the individual transport units are movable under the control of the control unit with individual movement profiles, so that they can independently perform their transport tasks at individual rhythms, possibly in different back-and-forth movements over different lengths of a pendulum stroke. In this case, it is advantageous to perform a separate calibration procedure for each transport unit. This ensures highly precise transport and removal of workpieces at each workstation.

[0035] However, the invention can also be used in forming machines where multiple transport units are firmly coupled to one another and moved back and forth parallel to a transport direction according to the same motion profile. One example of this is forming machines where the individual transport units of the transport system are installed at fixed positions, spaced apart from one another, on a common beam-shaped support. In this case, a precise coordinate alignment could be performed for one of the transport units; at the other workstations, additional individual setup work might be necessary to position or retrieve the workpieces as precisely as possible.It would be possible to mount the transport units at fixed positions on a common carrier, but to design the gripping units to be adjustable to a certain extent relative to the mounting position on the carrier so that the distances between the gripping units parallel to the transport direction can be individually corrected to match the distances between the workstations.

[0036] BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Further advantages and aspects of the invention emerge from the claims and from the description of embodiments of the invention, which are explained below with reference to the figures.

[0038] Fig. 1 shows a schematic oblique perspective view of a forming system for producing complex shaped parts from wire or tube according to one embodiment; Fig. 2 shows a detail of the forming machine from Fig. 1;

[0039] Fig. 3 shows another detail of the forming machine from Fig. 1; and

[0040] Fig. 4 shows a detail of a forming machine according to another embodiment with a bending station and a press station.

[0041] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] Figure 1 shows a schematic oblique perspective view of a forming system 100 for producing complexly shaped molded parts from wire or tube according to one exemplary embodiment. This is a computer-numerically controlled multi-station forming system on which complexly shaped molded parts can be produced primarily by forming and, if necessary, additionally modified by other processing operations. The computer-numerical control unit 190 for controlling all connected components can be housed, for example, in a control box.

[0043] The metallic starting material W (wire or tube) is in the form of a coiled material supply (not shown). The forming system comprises a finishing machine 200 for producing straightened workpieces WS of a predefined length from the initially curved starting material, as well as a forming machine 300 downstream of the finishing machine 200 for producing complexly bent and / or otherwise specifically modified formed parts from the straight workpieces.

[0044] The assembly machine has a feed device 270 for feeding workpiece material from the wound material supply, a straightening device 275 for straightening the workpiece material W and a downstream cutting device 280 for separating straightened workpiece sections WS from the supplied workpiece material.

[0045] Directly at the cutting device 280, the separated straight workpieces are transferred to the downstream forming machine 300. The loading station 400 of the forming machine is located there.

[0046] The forming machine 300 has a torsion-resistant machine frame 310 comprising a vertical mounting wall 312 whose vertical front side 313 is parallel to the xz-plane of the machine coordinate system MKS. The horizontal y-direction runs perpendicular to the front side 313. Flexible mounting structures with a plurality of horizontal, T-profile mounting grooves 314 arranged at a distance from one another are formed on the front side. These allow components of the forming machine to be attached at any position in the x-direction, in particular the components of tool-carrying processing units that are intended to form the workstations of the multi-station forming machine. In addition to the horizontal mounting grooves, mounting holes and other structures for fastening components can be present.The horizontal x-direction is also referred to as the longitudinal direction, the horizontal y-direction as the transverse direction and the z-direction as the height direction.

[0047] In the illustrated configuration, the forming machine 300 has four work stations, namely the loading station 400, which is located near the cutting device 280, and three forming stations arranged in a horizontal row, namely a first forming station 410, a second forming station 420 and a third forming station 430.

[0048] The first forming station 410 is designed as a bending station for bending the workpiece. It has four work units 412-1, 412-2, 412-3, and 412-4, each comprising a slide that can be moved linearly by means of a servo motor. The vertically stacked and vertically movable slides 412-1 and 412-2 each carry a clamping tool on their front sides for clamping or holding the workpiece WS in a desired spatial position. The tool of the lower slide 412-2 serves as a counter element to the bending slides and defines parts of the resulting shape. The two work units 412-3 and 412-4, which can be advanced at an angle from above, carry bending tools on their front sides that engage the clamped workpiece in a working stroke, thereby creating bends in the workpiece.

[0049] The second forming station 420 is equipped with three parallel work units 425-1, 425-2, and 425-3 arranged above the transport line. These work units feature linearly movable bending slides, allowing the already bent workpieces arriving there to be bent using the bending slides. The tool of the lower slide 412-4 serves as a counter element to the bending slides and defines parts of the resulting shape.

[0050] At the third forming station 430, three bending slides arranged at angles to each other are mounted. Additionally, a counter-tool is mounted that can be fed from below. This counter-tool serves as a counter element to the bending slides and defines parts of the resulting shape. The work units (e.g., bending slides) of the individual work stations can be moved variably. For example, they can be moved coupled or separately and can be operated force-controlled, position-controlled, or displacement-controlled.

[0051] The work units of a workstation are not mounted directly or immediately on the mounting wall 312, but indirectly via a common base support. This is explained using the first workstation 410 as an example.

[0052] All work units 412-1 to 412-4 of the first work station 410 are mounted on the front side of a common plate-shaped base support 415, which is also referred to here as the tool support plate 415. The fastening elements matching the mounting structures of the mounting wall 312 are attached to the opposite rear side of the base support 415.

[0053] The base support 415 and the work units 412-1 to 412-4 it supports are completely pre-assembled and configured before being attached to the mounting wall. They then form a first tool module 450-1, which is mounted as a whole on the mounting wall. The base support 415 defines a tool coordinate system (WKS) fixed to the support. All tool-supporting work units of the tool module are configured with reference to a common reference point RP-1 in the tool coordinate system fixed to the support or module (see Fig. 3).

[0054] For transferring or transporting the workpieces between the workstations, the forming machine has a transport system 500. This system has a modular design and, in the example shown, comprises four transport modules 550-1, 550-2, 550-3, and 550-4. Each of the transport modules is a separately pre-assembled unit that can be mounted, for example, via a support bracket on the front of the assembly wall or independently of the assembly wall 310.

[0055] All transport modules are nominally identical or largely identical in design and together ensure the successive transfer of consecutive workpieces from loading station 400 to all three subsequent processing stations and then to a removal station. This main transport direction runs in the x-direction.

[0056] The first transport module 550-1 is intended for transporting cut straight workpieces between the loading station 400 or cutting device 280 and the first work station or forming station 410. The second transport module 550-2 ensures transport between the first forming station 410 and the second forming station 420, etc.

[0057] The structure of the second transport module 550-2 is explained in more detail using the example of Fig. 2. A transport module has a narrow support structure 510 that is horizontally elongated in the x-direction. The length is only a fraction of the total length of the transport system between the loading station 400 and the pickup point, e.g., less than 50%, e.g., between 10% and 40% (depending on the number of transport modules in the entire transport route). The support structure can be attached to a bracket (not shown) at a certain distance from the front side 313 of the mounting wall 312, or it can be free-standing.

[0058] Each support structure carries a single transport unit 520, which is guided displaceably in the x-direction by means of a carriage 521 on two guide rails attached to the top of the support structure. To move the transport unit 520 in the x-direction (main transport direction), a module-specific drive system is provided, which comprises a transport drive 530, which in the example is designed as a servomotor with a vertical axis of rotation and is mounted at one end of the support structure. The servomotor drives a horizontally rotating toothed belt 524, which is guided over deflection pulleys in the axial end regions of the support structure. The carriage is attached to the toothed belt and, with the aid of the transport drive 530, can be moved back and forth in pendulum operation between a first end 521-1 closest to the transport drive 530 and a second end 521-2 furthest away from it.The distance between ends 521-1 and 521-2 is referred to here as the module transport distance and corresponds to the maximum stroke of the pendulum movement in the x-direction. Using this drive concept, pendulum movements with a shorter pendulum stroke in the x-direction can also be realized.

[0059] A pendulum movement does not have to cover the entire module transport path. The pendulum stroke of the actual pendulum movement runs between a first end position of the pendulum movement and the opposite second end position of the pendulum movement.

[0060] A base support 540 is attached to the carriage 521, which can be moved horizontally in the x-direction using the transport drive 530. This base support carries a gripper arm 545 with a rectangular profile that can be moved horizontally in the y-direction perpendicular to the module transport path. At its end facing the front wall, this gripper arm carries a mechanical gripping unit 560, which can be actuated pneumatically, for example, for gripping a workpiece. The horizontal movement (transverse stroke) of the gripper arm in the y-direction is generated by a drive 542, which is attached to the base support of the transport unit 520 and can move with it in the x-direction. A transport unit can be constructed, for example, using a suitably dimensioned, ready-to-install linear axis in the form of an omega module.

[0061] In some variants, the gripping unit is permanently mounted on the horizontally movable gripper arm. In other variants, the gripping unit can be rotated 180° around a gripping unit rotation axis oriented in the y-direction using a rotating assembly installed between the gripping unit and the gripper arm. The additional structure or length of this unit in the y-direction can be compensated for by the variable stroke in the y-direction. The gripper arms are preferably height-adjustable in a controlled manner. For the rotation and lifting / lowering functions, a pneumatic or servo-electric drive can be provided, for example. The movements can be freely programmed via the control unit.

[0062] The transport modules are arranged in two rows, one behind the other, in the horizontal xy plane. Due to the two-row arrangement with an offset in the main transport direction, the transport routes of immediately adjacent transport modules overlap within an overlap zone within a workstation. The length of the overlap zone can be up to almost half the length of the module transport route, so that there is a relatively wide area in front of each workstation that can be accessed by both the transport unit of an upstream transport module and the transport unit of the downstream transport module.

[0063] The modular transport system 500 offers a high degree of flexibility in terms of manipulation options. The stroke in the x-direction (main transport direction or direction of the x-pendulum movement) can be controlled at each workstation independently of the other workstations. The same applies to the stroke in the y-direction, which is also referred to as the transverse direction and enables the movement of the gripping units toward and away from the workstations. Due to the mutual overlap of the pendulum strokes of adjacent transport units, an overstroke in the x-direction is possible at each workstation. It is also possible to operate a workstation from two different sides (in the x-direction).

[0064] Thanks to the separate drives for the x-stroke and y-stroke, each transport module's gripping unit 560 can be flexibly moved in the x- and y-directions independently of the gripping units of the other transport modules. This results in, among other things, a high degree of flexibility in the spacing between workstations. "Spacing" here refers to the distance measured in the x-direction between adjacent workstations or their workpiece holding devices. The concept is highly flexible, not only with regard to different spacing between workstations. The assembly wall can also be expanded with one or more modules. Additional transport modules can then be attached as needed.

[0065] The forming machine is highly flexible with regard to the x-position of the individual workstations, allowing it to be optimally adapted to the sequence and type of process steps of a forming process. However, it would normally require a relatively long time to set up the forming machine after assembling the tool modules so precisely that the workpieces are placed precisely in the correct depositing or insertion position of the workstation served by the transport unit using the transport unit 520 and then picked up again at the correct location for further transport. If this is not done with sufficient precision, it can lead to disruptions in the operating process and / or to unacceptable errors in the part geometry.

[0066] To remedy this situation, a coordinate synchronization system is provided for synchronizing coordinates between the transport coordinate system (TKS) assigned to the transport unit 520 and the tool coordinate system (WKS) assigned to a respective workstation or tool module. Using the coordinate synchronization system, coordinate transformation data can be determined, which can be used by the control unit 190 during productive operation to synchronize each of the transport units 520 orto precisely control their gripping units so that a gripping unit of the transport units can be precisely positioned to a target position specified in the tool coordinate system, for example, the position the gripping unit should reach when transporting a workpiece (deposit position) and / or the position to which the gripping unit must move in order to grip the workpiece after completing the operation to be performed at a workstation and then transport it further. This is explained in more detail using Figs. 3 and 4.

[0067] The coordinate alignment system includes components that are assigned to the individual work units, as well as components that are assigned to the transport system or the individual transport units with their gripping units.

[0068] Fig. 3 shows, on the left, the loading station 400 with the cutting device 280, and, on the right, the first work station 410 following in the material flow, which is designed as a forming station in the form of a bending station. The four work units 412-1 to 412-4 are attached to the front of a rectangular tool carrier plate 415 and, together with the tool carrier plate supporting them, form a first tool module 450-1. After being attached to the tool carrier plate, the work units are aligned relative to this tool carrier plate and relative to one another with respect to a reference point RP-1, so that the tool module was completely aligned before it was attached to the assembly wall 310. The reference point RP-1 has known coordinates with respect to the tool coordinate system WKS, whereby generally only the coordinates in the x-direction (main transport direction) and in the z-direction (vertical direction) are of interest here.

[0069] The upstream cutting device 280 has a corresponding reference point RP-0 in relation to the tool coordinate system. Reference numeral 560 designates the gripping unit of the transport unit of the first transport module 550-1, which is responsible for transporting the workpiece WS cut from the wire supply from the loading station 400 or the cutting device to the first work station. In order to accomplish this transport precisely, the gripping unit must engage at a precisely predeterminable point in the front workpiece area before the straight workpiece WS is severed from the fed wire. The workpiece is then transported parallel to the wire feed direction orto the machine center line 317 and in the x-direction in the direction of the first work station 410 and is lifted slightly upwards in the process so that it can be positioned precisely in the area of ​​the first work station 410 with regard to the height direction and main transport direction so that the work units set up at the reference point RP-1 can bend the workpiece precisely at the intended sections. For this purpose, the workpiece WS is transported forward into its processing position in the engagement area of ​​the work units of the first work station. The vertical sliders of the work units 412-1, 412-2 are then advanced towards the workpiece until the workpiece is clamped between them. The gripper 560 of the first transport unit is then opened and moved back in the y-direction. The forming operation or bending operation then takes place by advancing the inclined work units.

[0070] The formed workpiece is then to be transported by the second transport unit toward the subsequent second work station 420. According to the process, the gripping unit 560-2 of the second transport unit grips the bent workpiece at a precisely specified location (pick-up position), moves it out of the work area of ​​the work units via a Y-stroke, and then transports it further in the Z-direction to the subsequent work station.

[0071] In order to be able to carry out this work operation of the transport system with precise positioning, the control unit 190 must know to which positions in the transport coordinate system the transport units or their gripping units must be moved in order to reach the desired target position in the tool coordinate system.

[0072] For this purpose, a coordinate alignment operation is performed in a setup operation using the components of the coordinate alignment system. In the example case, a tactile probing device 610 is mounted on the horizontally movable arm of the first transport unit 520-1. This device has a probe tip whose position in the transport coordinate system is known. Using this probe tip, the vertical front edge KV and then the horizontally aligned bottom edge KU of the tool carrier plate 415 are first probed. The probe can also be probed in the reverse order. The probing operation determines the x-coordinate of the front edge and the z-coordinate of the bottom edge in the transport coordinate system.

[0073] The edges of the tool carrier plate intended for probing serve as a probable auxiliary structure on the tool module. They define an auxiliary zero point HP, which in this case, for example, is located at the corner where the probing edges meet. The relative position of the edges to the reference point RP can be specified by the offset VX in the x-direction with respect to the leading edge KV and the offset VZ with respect to the probable lower edge.

[0074] Instead of approaching the edges of a tool carrier plate individually, it would also be possible for the tactile probe to approach a defined hole in or on the tool carrier plate. In this case, the hole serves as an auxiliary structure.

[0075] Using this offset data, it is now possible to align the tool coordinate system (WKS) and the transport coordinate system (TKS). For example, the x-position of the reference point (RP) results from the sum of the coordinates of the leading edge (KV) in the transport coordinate system and the offset (VX) between the leading edge and the reference point.

[0076] In order to enable the control unit to control the movements of the transport unit using the offset data in such a way that precisely definable target positions in the tool coordinate system can be approached precisely, the control unit requires the offset data in addition to the information obtained by probing auxiliary structures on the tool module.

[0077] In one embodiment, the offset data is encoded in an optically readable data carrier DT on the tool module. For example, a QR code can be affixed there or arranged in some other way. A QR scanner or a camera can be mounted on the transport unit 520-1 or 520-2, which delivers image data to the control unit 190. This can contain decoding software to determine the offset data encoded in the QR code and store it in a memory. The offset data can also be specified in plain text and captured by a camera on the transport unit and converted into storable offset data using image processing (text recognition). Alternatively, an RFID chip could be used as a data carrier, which could be read by a read head mounted on the transport unit.

[0078] The control unit 190 can access this memory for subsequent control during productive operation. In a similar way, the two coordinate systems (tool coordinate system and transport coordinate system) can be synchronized with each other at all workstations.

[0079] As a further example, Fig. 4 shows the first work station 410 on the left and, to the right, a second work station 470, which is designed not as a bending station but as a pressing station 440. The pressing unit has a die located below and a slide arranged above, which, in cooperation with the die below, forms the section of the already pre-bent workpiece WS inserted between them by pressing. The illustration illustrates that aligning the two tool carrier plates to the machine centerline 317 is not necessary. For control purposes, it is sufficient if the coordinates of the corresponding reference points RP1, RP2 in the transport coordinate system are known.

[0080] The equipment of the forming machine is only an example. In addition to two or more forming stations, other processing stations and / or other work stations may be provided. For example, a section with a thread, grooves, knurl or the like may be required on the molded part to be produced. The production of a thread can be carried out, for example, using a flat-die roller, which can be arranged, for example, between the cutting device 280 and the first forming operation at the first forming station 410. Thread production using a rolling head can be provided at the end of the operation, i.e. downstream of the third forming unit 430. If necessary, machining can also be carried out on the separated workpiece, for example by chamfering, leveling or pointing.A corresponding machining station can be arranged, for example, between the cutting device 280 and the first forming station 410, so that machining can be performed on the still straight workpiece. At least one workstation can, if necessary, comprise a CNC press, for example, to produce a flattened section on a molded part made of round material. A measuring station can also be provided, for example, to optically determine the geometry of the measured molded part using a camera and image processing.

Claims

Patent claims 1. A forming machine (100) for producing complex shaped parts from straight workpieces (WS) made of wire or tube under the control of a computer numerical control unit (190), comprising: a plurality of work stations comprising a loading station (110), a first processing station (410) downstream of the loading station, and at least one second processing station (420) downstream of the first processing station (410); a machine frame with mounting structures for mounting tool-carrying work units to form work stations; a transport system (500) for transporting successive workpieces (WS) from the loading station (400) to downstream work stations under the control of the control unit (190);wherein the transport system has a plurality of transport units (520), each having a gripping unit (560) for gripping a workpiece and being movable back and forth between a first end position (522-1) and a second end position (522-2) of a pendulum stroke under the control of the control unit (190), the first end position being assigned to one of the work stations and the second end position being assigned to a work station downstream of this work station;characterized in that the forming machine has components of a coordinate adjustment system for adjusting coordinates between a transport coordinate system assigned to a transport unit and a tool coordinate system assigned to a respective workstation in order to determine coordinate transformation data, and the control unit (190) is configured to control a transport unit using the coordinate transformation data in such a way that a gripping unit (560) of the transport unit can be controlled with precise positioning to a target position that can be specified in the tool coordinate system.; 2. Forming machine according to claim 1, characterized in that flexibly usable mounting structures are provided on the machine frame, wherein preferably the forming machine comprises a machine frame with a mounting wall (310) which has on a front side (313) flexibly usable mounting structures with a plurality of mounting grooves (314) and / or mounting holes for mounting work units to form the work stations, wherein preferably the mounting structures have a plurality of mounting grooves (314) arranged at a distance one above the other and oriented parallel to a transport direction of the transport system, which mounting grooves are designed in such a way that Working units and / or other components can be mounted at any position along the mounting grooves.

3. Forming machine according to claim 1 or 2, characterized in that the coordinate adjustment system is configured for an automatic adjustment between the transport coordinate system (TKS) and the tool coordinate system (WKS).

4. Forming machine according to one of the preceding claims, characterized in that at least one of the work stations, in particular several or all work stations, has a tool module (450) mounted on the machine frame, which comprises a base support (415) mounted on the machine frame, which supports two or more, in particular all, work units of the work station, wherein the work units carried by the base support are set up with reference to a common reference point (RP-1) in the tool coordinate system fixed to the support.

5. Forming machine according to one of the preceding claims, characterized in that a working unit or a tool module (450) has an auxiliary structure (VK, UK) which can be touched optically, mechanically or in another way and which has an offset relative to the reference point (RP-1) which can be described via offset data (VX, VZ), and in that the coordinate adjustment system has a device for storing the offset data or data derived therefrom.

6. Forming machine according to one of the preceding claims, characterized in that the coordinate adjustment system has at least one probing device for probing the auxiliary structure, which is mounted or can be mounted in the correct position on a transport unit and can be moved with the transport unit in the mounted state.

7. Forming machine according to one of the preceding claims, characterized in that the tool module (450) has a preferably automatically readable data carrier (DT) which has the offset data or access data for accessing the offset data, wherein the data carrier preferably has a QR code or a barcode or a text marking or an RFID chip, and wherein a reading device compatible with the data carrier is mounted on a transport unit responsible for the workstation, at least during a setup operation.

8. Forming machine according to one of the preceding claims, characterized in that the transport units can be moved independently of one another with an individual movement profile under the control of the control unit (190).

9. Method for setting up a forming machine for producing complex shaped parts from straight workpieces (WS) made of wire or tube under the control of a computer numerical control unit (190), comprising the following steps: Providing a machine frame with flexibly usable mounting structures for mounting tool-carrying work units to form workstations; Mounting work units on the machine frame to form a plurality of work stations comprising a loading station (110), a first processing station (410) downstream of the loading station and at least one second processing station (420) downstream of the first processing station (410); Assembling components of a transport system (500) for transporting successive workpieces (WS) from the loading station (400) to downstream workstations under the control of the control unit (190); wherein the transport system has a plurality of transport units (520), each having a gripping unit (560) for gripping a workpiece and, under the control of the control unit (190), being movable back and forth in a pendulum operation between a first end position (522-1) and a second end position (522-2) of a pendulum stroke, wherein the first end position is assigned to one of the workstations and the second end position is assigned to a workstation downstream of this workstation;characterized in that, in order to set up the forming machine, a set-up operation is carried out which comprises a coordinate comparison operation in which coordinates between a transport coordinate system assigned to a transport unit and a tool coordinate system assigned to a respective work station are compared and coordinate transformation data are determined from the comparison and processed and stored in such a way that, in production operation, movements of a transport unit can be controlled using the coordinate transformation data in such a way that a gripping unit of a transport unit can be controlled with precise positioning to a target position which can be specified in the tool coordinate system.; 10. Method according to claim 9, characterized in that the target position is specified as the position which the gripping unit is to reach when transporting a workpiece and / or the position at which the gripping unit is to be positioned in order to to be picked up after completion of the operation to be performed at a workstation and then transported further.

11. Method according to claim 9 or 10, characterized in that during assembly of the forming machine at least one tool module is pre-assembled and set up away from the machine frame and that the tool module is then mounted on the machine frame, wherein for assembling a tool module a base carrier configured for assembly on the machine frame is equipped with several working units and all working units of the tool module are set up with reference to a common reference point in a carrier-fixed tool coordinate system.

12. Method according to claim 11, characterized in that when setting up the forming machine, the position of the tool module mounted on the machine frame is determined and data representing this position are made available to the control unit during coordinate adjustment.

13. Method according to claim 9, 10, 11 or 12, characterized in that the transport units are movable under the control of the control unit with an individual movement profile and that a separate adjustment procedure is carried out for each transport unit.

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