DE102022204106A1 - Bending machine and wire processing system with bending machine - Google Patents

Abstract

A bending machine (300) for producing complex bent parts from straight wire rods (DS) comprises a computer numerical control unit (190) and a transport system (310) for transporting successive wire rods along a transport route (312), the transport system comprising a plurality of transport units (320). and each transport unit (320) has a workpiece receiving device (325) for receiving an individual wire rod (DS) and can be moved along the transport route (312) via control signals from the control unit (190). Furthermore, several work stations are provided, which are arranged along the transport route (312), with at least two of the work stations being designed as bending stations (BS1, BS2, BS3). The transport system (310) has for a number of the transport units (320), e.g. for each of the transport units, at least one support unit (720) which can be moved along the transport route and which comprises a support member (730) which is configured to provide a free section of a to contact the wire rod (DS) picked up by the workpiece receiving device (325) of the transport unit outside an engagement area of the workpiece receiving device (325) for mechanical stabilization of the free section.

Description

The invention relates to a bending machine for producing complex bent parts from straight wire rods according to the preamble of claim 1. The invention further relates to a wire processing system which includes such a bending machine.

A bending machine of the type considered here comprises a computer numerical control unit, a transport system for transporting successive wire rods along a transport route and a plurality of work stations arranged along the transport route, at least two of the work stations being designed as bending stations. The transport system has a large number of transport units. Each transport unit has a workpiece receiving device for holding an individual wire rod and can be moved along the transport route via control signals from the control unit. It is a computer numerically controlled multi-station bending machine that can process wire rods. Such bending machines are usually used when it comes to producing large numbers of complex bent parts in a short time. A complex bent part is a bent part that has more than one bend, some of the bends also being in different planes, so that a three-dimensionally bent part is present.

The document DE 10 2020 212 558 A1 discloses a bending machine of the type mentioned above, in which each transport unit can be moved along the transport route via control signals from the control unit according to an individual movement profile. The bending machine offers high productivity and great flexibility in the production of bent parts with different bending geometries and is also characterized by its compact size and correspondingly small space requirement.

There is a need for complex bent parts in the area of electromobility, among other things. Vehicles with fully or partially electric drives are increasingly being offered there. The vehicles usually have powerful energy storage systems with several battery modules. The electrical energy must be transported between the individual battery modules. For this purpose, insulated and curved copper or aluminum busbars are used, which are also known as “busbars”. Furthermore, the cable harnesses that run longitudinally between the front and rear of vehicles are increasingly being replaced by busbars. Since the installation space available for laying busbars is sometimes relatively narrow and geometrically complex, busbars that have bends in one or more places are required in many cases.

Wire materials in the form of insulated and bent copper or aluminum wires with a substantially rectangular or square cross-section are also often used to produce coil elements for building stators for electric motors, so-called “hairpins”.

Such bent parts are sometimes made from wire rods that are comparatively long and thin relative to their length. Their safe handling during the manufacturing process is not always easy, especially when working with short cycle times.

TASK AND SOLUTION

Against this background, the invention is based on the object of providing a bending machine of the type mentioned above, which operates reliably even with short cycle times, regardless of the bending part geometries to be produced.

To solve these and other tasks, the invention provides, according to a formulation of the invention, a bending machine with the features of claim 1. Furthermore, a wire processing system with the features of claim 17 is provided. Advantageous further developments are specified in the dependent claims. The wording of all claims is incorporated by reference into the content of the description.

In a generic multi-station bending machine, the transport system comprises several transport units, each of which has a workpiece receiving device for receiving a single wire rod. The transport units can be moved along the transport route via control signals from the control unit. According to a formulation of the claimed invention, the transport system for a number of the transport units has at least one support unit movable along the transport route, which comprises a support member which is configured to hold a free section of a wire rod received by the workpiece receiving device of the transport unit outside the engagement area of the workpiece receiving device, preferably at a distance from the engagement area to contact for mechanical stabilization of the free section.

At least one support unit can be provided for each of the transport units, so that the number of support units corresponds to the number of transport units. It is also possible, that no support unit is provided for one or more transport units. In any case, a support unit should be provided for at least one of the transport units.

Depending on the type of bent parts to be manufactured, it may happen that a wire rod has to be accommodated in the workpiece holding device in such a way that a relatively long piece of the wire rod protrudes beyond the engagement area of the workpiece holding device in the transport direction or on the opposite side (opposite to the transport direction). Depending on the thickness, the cross-sectional shape and the material stiffness of the wire material, it may be that the relatively long free section bends downwards due to its own weight under the influence of gravity, so that a free end removed from the workpiece receiving device no longer extends with sufficient accuracy the receiving axis of the workpiece receiving device lies. In addition, there may be oscillatory movements of the free section. Under these circumstances, problems can arise when threading the free section into the area of the bending tools of a bending station, including a collision between the wire rod and the bending tool. According to the claimed invention, this danger is systematically avoided by supporting and thereby stabilizing the free section outside the engagement area, usually at a suitable distance from the engagement area.

The stabilization relates, on the one hand, to the alignment of the free section, which should be such that before the first bend is created, the free section runs essentially coaxially to the receiving axis of the workpiece receiving device. Due to the mechanical contacting, oscillatory movements of the free section can also be largely suppressed, so that collision-free threading of the free end in the area of the bending tools of the next bending station is ensured. This means that even with wire rods with initially relatively long and/or unstable free lengths, trouble-free operation can be ensured even with high cycle times and correspondingly high transport speeds and/or accelerations.

This measure has proven successful, among other things, in the production of hairpins with relatively long leg lengths. For these bent parts, the required initial length of the straight wire rods can be so long that the aforementioned problem of deflection and strong vibration arises.

Another problem recognized by the inventors is that the locations where the individual bends should be made can change from bending station to bending station and depending on the desired final geometry of the bent part. According to a further development, this problem is taken into account in that a distance between the workpiece receiving device and the support member is adjustable, preferably continuously, via control signals from the control unit. This makes it possible to set and approach the optimal support point (at least one) for each bent part geometry in each phase of a process by programming the control unit, whereby the support length then becomes variable. If several bending operations are required at different locations on a free section, the distance can be adjusted gradually as the multi-stage bending operation progresses. By adjusting the distance, it is also possible to move the support member up to the outlet end of the workpiece holding device, so that in practice only a short extension of the clamping length results and the majority of the free wire section is available for bending operations.

In order to increase the flexibility of the bending machine for processing a wide variety of component geometries, some embodiments provide that a support unit has at least one integrated actuator, which can be controlled via control signals from the control unit and is configured to switch the support member between different working positions. For example, a height adjustment and/or a transverse adjustment can be effected. The actuator can be, for example, an electromechanical or pneumatic actuator. However, the support unit can also be constructed as a passive unit without an integrated actuator, making the structure particularly cost-effective and robust.

In some embodiments it is provided that a transport unit is assigned at least one support unit, which has a support member which can be adjusted in height via control signals from the control unit. The support member can then, for example, have a working position in which the support surface is so close to the extension of the receiving axis of the workpiece receiving device that the wire rod is supported coaxially to the receiving axis. However, if the wire rod already contains at least one bend, it may be necessary to support the free section at a different height or in a different location. The height adjustment can be used for this. Alternatively or additionally, adjustability in the transverse direction and/or adjustability in an axial direction (for distance adjustment) running parallel to the receiving axis of the workpiece receiving device can be provided.

In some embodiments, a particularly high level of flexibility in the production of a wide variety of bent part geometries is achieved in that at least one support unit is designed as an individually controllable support unit, which can be moved along the transport route independently of an assigned transport unit via control signals from the control unit. Preferably, several such support units are provided; in particular, all support units can be designed as individually controllable support units. This configuration makes it relatively easy, among other things, to adjust the distance between the workpiece receiving device and the support member, namely by moving the completely individually controllable support unit to the appropriate position relative to the transport unit.

An individually controllable support unit can have an integrated self-drive for movement along the transport route, which can be controlled via the control unit.

The support according to the invention for mechanical stabilization can be provided in transport systems that have a fixed timing, in which all transport units are moved in the same way in unison. However, the transport system is preferably designed for variable timing. The term variable timing means that not all transport units are in the same state of movement at a given time, but that they can carry out their individual transport tasks according to an individual movement profile, whereby these movement profiles can differ at least in phases.

In some such embodiments, the transport system has a transport route with at least one linear motor unit and guide rails for guiding the movement of the transport units, wherein the transport units can be moved magnetically along the guide rails via the linear motor unit under control by the control unit. In particular in such embodiments it can be provided that the individually controllable support units are guided in the same way as the transport units and can be moved individually via the linear motor unit under control by the control unit.

Particularly in the variants with individually controllable support units, it is preferably provided that each of the transport units has a base element on which components of the workpiece receiving device are mounted, and that the individually controllable support units have a base element which is essentially identical in construction to the base element of the transport unit and which carries the support member . This brings, among other things, manufacturing advantages and cost advantages when producing through mass effects, and the movement of the individually controllable support units can also be controlled in the same way as with the assigned transport units.

Transport units and support units can be arranged alternately along the transport route, so that a support unit is arranged behind a leading transport unit in the transport direction and at the same time in front of a next, lagging transport unit in the transport direction. This further increases flexibility. The same support unit can be used to support either a rear free section on the leading transport unit or a front free section on the trailing transport unit.

An individually controllable support unit can have a support member which has a support surface that can be adjusted in height by means of a height adjustment device via control signals from the control unit. It is then possible to support an individual controllable support unit for support at at least two different heights. Alternatively or additionally, the support member can be adjusted in the transverse direction.

According to a further development, it is provided that an individually controllable or an integrated support unit has an adjusting device for adjusting a position of the support member in relation to a base element of the support unit or the transport unit, that the support unit is assigned an individually controllable actuating unit that can be moved along the transport route, and that the actuation unit is mechanically coupled to the adjustment device of the support unit via a mechanical coupling device or a gear in such a way that the adjustment device can be actuated by changing the distance between the actuation unit and the support unit. The gearbox (or the mechanical coupling device) is designed in such a way that it transfers a change in distance between the actuating unit and the support unit (gearbox input) into a change in position of the support member (output member) in accordance with its design-related transfer function. As a result, for example, a controllable height adjustment of the support member of the support unit can be realized. The support unit and the actuation unit can each be constructed relatively simply; the support unit does not require an integrated actuator, since the associated actuation element serves as an actuator.

The mechanical coupling device can, for example, have a toothed belt which is fixed to the actuation unit and interacts in the support unit with a gearwheel that meshes with it, which then effects, for example, a height adjustment of the support member. Alternatively, the coupling device can have, for example, an obliquely oriented coupling rod articulated on both sides. The coupling device can also be designed in the manner of a coupling gear with several gear members, for example in the manner of a scissor joint.

It is also possible for a second transport unit, which may be identical in construction to an immediately adjacent first transport unit, to be assigned to this first transport unit as an individually controllable support unit. The use of a transport unit as a support unit is suggested here. In this case, the workpiece receiving device of the second transport unit is used as a support element for calming and supporting the free section of the wire rod held by the first transport unit. For this purpose, the workpiece receiving device used as a support element is fixed in an open position.

While the wire rod is clamped and thus held in the workpiece holding device of the first transport unit used as a transport unit, the open workpiece holding device of the second transport unit, which is “misused” as a support unit, serves as a support element for supporting the free section of this wire rod.

The second transport unit used as a support unit can have a workpiece receiving device (used as a support member) which is rotatable about its receiving axis. Such a wire support can, for example, rotate synchronously with the clamping of the first transport unit when twisting.

The workpiece holding device of the second transport unit used as a support unit can be brought into a closed position at the bending station by the external clamping device of the bending station in order to clamp the wire rod as close as possible to the bending head.

The use of individually controllable support units offers a number of advantages, but is not mandatory. According to a further development, it is also possible for at least one transport unit to have an integrated support unit, so that the support unit is a structural component of the transport unit and can be moved together with it. It is preferably provided that a base element of the transport unit carries components of the workpiece receiving device and the support member of the support unit is mounted on a component of the transport unit relative to the workpiece receiving device. The support member can be mounted, for example, on the base element of the transport unit or on the workpiece receiving device itself.

In some embodiments it is provided that the support member can be advanced in relation to the receiving axis of the workpiece receiving device in a feed direction that runs transversely, in particular perpendicular, to the receiving axis of the workpiece receiving device. The support member can then be switched between a retracted neutral position and a support position in relation to this receiving axis. This functionality is useful, for example, if in a final phase of a series of bending operations the support member is to be moved out of the area between the workpiece holding device and the bending tool in order to enable bend generation close to the engagement area of the workpiece holding device.

There are different options for the structural design of the supporting member. In some embodiments, the support member has a wide support surface across the transport route, i.e. in the transverse direction, which lies at the same height level over a certain width. A length of the support surface measured perpendicular to the transport route can, for example, be several centimeters, in particular in the range of 50 to 150 mm. This ensures support in particular even if there is a curve in the transport route or part of a curve between the position of the transport unit and the position of the support unit.

It may be sufficient if a support member has a support surface that lies below the level of the wire section to be supported, so that the wire section rests on the support surface under its own weight. There is also the possibility of designing the support member in such a way that it is supported on several sides. In some embodiments, the support unit has a lower support surface and an upper support surface arranged at a height distance above the lower support surface, wherein a gap formed between the support surfaces has a height that essentially corresponds to the height of the wire rod such that the wire rod is horizontal with little height play fits movably into the gap. This means that a wire rod can be supported essentially bidirectionally in the vertical direction, so that, among other things, multiple jumps on the lower support surface can be prevented.

It is also possible for a support member to be designed as a clamping device. To operate the clamping device, the support unit can be assigned an actuator that can be controlled via the control unit and which actuates the clamping device and can switch between a clamping position and a release position.

It is also possible for a support member to be mounted so that it can rotate about a horizontal axis of rotation. For this purpose, the support element can be designed as a passively rotatable support element, which does not have its own rotary drive, but is rotated or taken along if necessary via the wire rod rotating around its axis. This means that the wire rod can be supported without interruption during a twisting operation if necessary. This functionality is particularly useful in conjunction with bending stations designed for rotary draw bending.

In some embodiments, a transport unit with an integrated support unit has a support member which is movably guided relative to a base element of the transport unit along a guide parallel to the receiving axis of the workpiece receiving device and is spring-loaded by means of a spring arrangement in the direction of an end position remote from the workpiece receiving device. The end position can then be determined by a corresponding stop and the distance to the workpiece receiving device can be adjusted accordingly so that in the absence of external forces, the support member supports the wire rod in accordance with its end position. If the transport unit is then advanced in the direction of a bending station, the spring-loaded support member can strike a corresponding counter-stop at the bending station and is then pressed against the force of the spring in the direction of the workpiece receiving device as the transport unit advances further, while an increasingly larger free length protrudes from the support member on the side opposite the workpiece receiving device and can be threaded into the area of the bending tools. A locking device can be provided to prevent unwanted restoring movements of the support member when the load is relieved.

BRIEF DESCRIPTION OF DRAWINGS

• 1 zeigt eine schematische Seitenansicht einer Drahtverarbeitungsanlage gemäß einem Ausführungsbeispiel;
• 2 zeigt schematisch den Bereich der Stabübergabe und der Ladestation der Biegemaschine;
• 3A bis 3D zeigen verschiedene Phasen einer mehrstufigen Biegeoperation mit Abstützung eines freien Abschnitts des Drahtstabs durch eine verfahrbare Stützeinheit gemäß einem Ausführungsbeispiel;
• 4 zeigt ein Ausführungsbeispiel einer Stützeinheit mit einem Stützorgan, das einen seitlich offenen Führungsschlitz aufweist;
• 5 zeigt ein Ausführungsbeispiel einer Stützeinheit mit einem passiv drehbaren Stützorgan;
• 6 zeigt ein Ausführungsbeispiel einer Stützeinheit mit einem als Klemmeinrichtung ausgeführten Stützorgan;
• 7 zeigt ein Ausführungsbeispiel einer Stützeinheit mit einem höhenverstellbaren Stützorgan;
• 8A und 8B zeigen ein Ausführungsbeispiel einer Transporteinheit mit einer integrierten Stützeinheit, die ein höhenverstellbares Stützorgan und eine Abstandsverstellung zwischen Stützorgan und Werkstückhalteeinrichtung aufweist;
• 9 zeigt ein Ausführungsbeispiel einer Transporteinheit mit einer integrierten Stützeinheit, die ein in drei Dimensionen verstellbares Stützorgan aufweist;
• 10A und 10B zeigen verschiedene Phasen der Nutzung eines Ausführungsbeispiels, bei dem der Stützeinheit eine individuell steuerbare Betätigungseinheit zugeordnet ist, die auf eine Höhenverstellung des Stützorgans wirkt;
• 11A und 11B zeigen verschiedene Phasen der Nutzung eines Ausführungsbeispiels, bei dem der Stützeinheit ein individuell steuerbare Betätigungseinheit zugeordnet ist, die auf ein als Klemmeinrichtung ausgelegtes Stützorgans wirkt;
• 12A bis 12D zeigen verschiedene Phasen der Nutzung eines Ausführungsbeispiels, bei dem die Transporteinheit eine integrierte Stützeinheit aufweist, deren Stützorgan als federbelastete Drahtführung ausgelegt ist.

Further advantages and aspects of the invention result from the claims and from the description of exemplary embodiments of the invention, which are explained below with reference to the figures.

• 1 shows a schematic side view of a wire processing system according to an exemplary embodiment;
• 2 shows schematically the area of the bar transfer and the loading station of the bending machine;
• 3A until 3D show different phases of a multi-stage bending operation with support of a free section of the wire rod by a movable support unit according to an exemplary embodiment;
• 4 shows an embodiment of a support unit with a support member that has a laterally open guide slot;
• 5 shows an exemplary embodiment of a support unit with a passively rotatable support member;
• 6 shows an exemplary embodiment of a support unit with a support member designed as a clamping device;
• 7 shows an exemplary embodiment of a support unit with a height-adjustable support member;
• 8A and 8B show an exemplary embodiment of a transport unit with an integrated support unit, which has a height-adjustable support member and a distance adjustment between the support member and the workpiece holding device;
• 9 shows an exemplary embodiment of a transport unit with an integrated support unit, which has a support member that is adjustable in three dimensions;
• 10A and 10B show different phases of the use of an exemplary embodiment in which the support unit is assigned an individually controllable actuation unit which acts on a height adjustment of the support member;
• 11A and 11B show different phases of the use of an exemplary embodiment in which the support unit is assigned an individually controllable actuation unit which acts on a support element designed as a clamping device;
• 12A until 12D show different phases of the use of an exemplary embodiment in which the transport unit has an integrated support unit, the support member of which is designed as a spring-loaded wire guide.

DETAILED DESCRIPTION OF THE EMBODIMENTS

1 shows a schematic side view of a wire processing system 100 according to an exemplary embodiment. The wire processing system 100 is set up to produce complex bent parts in the form of coil elements for stators Manufacture electric motors (“hairpins”). A starting material (also referred to as a workpiece) is processed which has a wire-shaped electrically conductive carrier material (e.g. made of copper) with a substantially rectangular cross-sectional shape, which is covered by an electrically non-conductive insulation layer made of paint, thermoplastic or the like. is enveloped. The workpiece is hereinafter also referred to as “wire” D or insulated wire. The wire processing system is basically also suitable for processing round material (insulated or without insulation).

The computer numerically controlled, multi-axis wire processing system 100 has several controllable machine axes, a drive system with several mostly electric drives for driving the machine axes and a computer numerical control device 190 for coordinated control of work movements of the machine axes in a manufacturing process according to a computer-readable control program specific to the manufacturing process. A machine axis has at least one drive, e.g. an electric motor. The drive drives a movably mounted component of the machine axis. Depending on the type of movement of the component to be driven (rectilinear movement or rotary movement), a distinction is made between translational machine axes, which are also referred to here as linear axes, and rotary machine axes, which are also referred to here as rotation axes. A linear axis can, for example, drive a linearly movable slide. A rotation axis can drive a turntable, for example.

In the exemplary embodiment, the wire processing system has a rectangular machine coordinate system MK, marked with lowercase letters x, y and z, with a vertical z-axis and horizontal x and y axes. In the example shown, the x-axis runs parallel to the axis of travel of the wire. A distinction must be made between the coordinate axes x, y and z and the regulated machine axes, some of which are designated with capital letters (e.g. A-axis) on arrows. The arrows or double arrows represent the work movements that can be generated via the respective machine axes or their drives.

The starting material D is in the form of a wound material supply (coil), which in the example is wound on a reel 105. In other embodiments, no reel is provided; the material supply can also lie in, for example, a barrel-shaped storage and be withdrawn from it.

The workpiece enters a bar assembly machine 200 with an integrated stripping device 250. The rod assembly machine 200 has its own base 205 and includes, in this order along the pass axis of the workpiece, a straightening unit 220, a length measuring device 230, the stripping device 250 equipped with a milling device 240, a brush device 260 connected downstream of this, a feed device connected downstream of this 270 and one of the feed device downstream cutting device 280.

The cutting device 280 is connected immediately downstream of the feed device and separates straight wire rods DS of a predetermined length from the supplied, partially stripped wire. These are then transported one after the other using a bar transfer device 290 to a downstream bending machine 300. The longitudinal direction (direction of the longitudinal central axis) of the wire rods DS runs horizontally and parallel to the transport direction of the wire rods. This can be particularly advantageous for relatively thin wires, as it can avoid unwanted deformations during accelerated movements. This also results in relatively short delivery paths for bending units, which can have a positive effect on processing speed.

The bending machine 300 has its own base 305, on the top of which components of a transport system 310 for transporting successive wire rods along a transport route 312 are attached. The transport route runs in a horizontal plane (xy plane). In 1 For illustrative purposes, the transport route is shown in the area of the base 305 in a schematic top view of the transport level.

The transport route 312 is closed in the circumferential direction and has a substantially rectangular shape with long sides running in the x direction and shorter broad sides running in the y direction. There are 90° curve sections in the corner areas.

The transport system 310 includes a plurality of individual transport units 320, for example three, four, five, six, seven, eight, nine, ten or more transport units. The number of transport units should preferably correspond to at least the number of work stations so that the work steps can be carried out in parallel with one another. Preferably there can be more transport units than work stations.

Each transport unit has a workpiece receiving device 325 for receiving a workpiece individual wire rod DS. This runs in the area of the workpiece receiving device coaxially to its horizontal receiving axis 326 and parallel to a direction of travel that corresponds to the local transport direction on the transport route.

Each movement of a transport unit 320 can be carried out according to an individual movement profile, which can be specified by the control unit 190 based on a computer program. The drive for the transport movement, i.e. for the movement along the transport route 312, is controlled accordingly or supplied with power. The movement profile can be characterized, for example, by the distance covered during the movement, the speed and/or the acceleration of the movement as a function of time or other parameters.

The transport units 320 are moved via linear direct drives. The transport route 312 is constructed with a large number of linear motor units connected in series, on which there are guide rails to guide the horizontal movement of the transport units. The powered primary parts of the linear motor are located in the transport route 312, and passive components (secondary parts) of the linear motors are located within the transport unit 320, so that a transport unit 320 does not have a traveling drive for movement along the transport route.

In the exemplary configuration, the bending machine 300 has three bending stations arranged one after the other along the transport route 312, namely a first bending station BS1, a second bending station BS2 arranged behind it in the transport direction and a third bending station BS3 arranged behind it at a greater distance in the transport direction. During operation, the bending stations can be parallelized, i.e. work at the same time at least in phases, which makes high unit outputs possible.

A bending unit is arranged at each bending station, with which a bending operation can be carried out on the wire rod. There are two different types of bending units in the configuration shown. A base bending unit 340-2 (bending unit of the second type) is attached to the first bending station BS1, with a horizontal bending head axis. A rotary draw bending unit 340-1 (bending unit of the first type) is attached to the second bending station BS2, with the bending head axis aligned vertically. At a greater distance behind, a basic bending unit 340-2 is again attached to the third bending station BS3, but with a vertical bending head axis.

Each bending station is also set up to carry out geometry measurements on the bent part manufactured there. 1 shows the cameras 355 of the assigned measuring systems. This means that the bending stations can also function as measuring stations for the bending machine. In other exemplary embodiments, there are separate measuring stations that are located at a distance downstream of a bending station. There are also embodiments without a measuring system.

A bending station does not have its own workpiece holding device for holding the piece of wire to be bent. This is held during the bending operation by the workpiece holding device 325 of the transport unit 320 that is in the processing position. In order to ensure that the piece of wire does not slip during the bending operation due to the forces occurring within the relatively flexible clamping workpiece holding device 325, a bending station has a clamping device. With the help of the clamping device, a force can be exerted on the movable holding element 327 of the workpiece holding device 325, whereby the piece of wire is clamped in the workpiece holding device 325 so that it cannot be pulled out. When the clamping device engages, all forces directed to the workpiece holding device via the wire are absorbed by the clamping device, so that the transport unit 320 is relieved of the bending forces and accordingly no special design measures are required for high mechanical stability.

The workpiece receiving device 325 of a transport unit 320 or its components that come into contact with the workpiece are rotatably mounted about a receiving axis 326. During a bending operation, this runs parallel to the direction of travel. For this purpose, the holding elements of the workpiece receiving device 325 of a transport unit 320 can be mounted in a rotatable sleeve, so that the workpiece receiving device or its holding elements can be rotated about the longitudinal direction of the received wire rod or about the direction of travel. A bending unit may be designed to be able to generate rotation of the workpiece-contacting components of the workpiece holding device 325 about the longitudinal axis of the wire using a rotary machine axis, if necessary.

This makes it possible, among other things, to rotate the holding elements around the axis of the held wire section during rotational bending, so that there is not just one bend on the piece of wire is created, but at the same time also a twisted section, i.e. a permanent deformation of the wire rod, which is caused by torsion or twisting of the wire rod.

In the example case of 1 three consecutive bending operations are carried out before the finished bent part is removed from its transport unit at an unloading station 380. This can work similarly to the loading station and includes a gripper 392, which grips the finished bent part and transports it for further processing or further processing.

To ensure a consistently high quality of the finished bent parts, a measuring system is provided for each bending station, with which geometric parameters of the bent wire rod are recorded after the bending operation has been completed and reported to the control unit 190 in the form of measurement signals or measurement data derived therefrom. This carries out a target/actual comparison of the geometries and can then change the bending parameters of the assigned bending station at this stage if the measured actual geometry deviates too much from the target geometry stored in the control unit, so that the bending geometry is also included in a subsequent piece of wire can be generated with less error. The measurement signal from a measuring station can also be used to change bending parameters at a subsequent bending station so that an error that may have occurred at a bending station can be partially or completely corrected at one or more subsequent bending stations.

The components described up to this point are also in the wire processing system DE 10 2020 212 558 A1 available, which is why reference is made to the description there for further details.

The exemplary embodiment of the present application includes further components which, among other things, can further improve the handling of particularly unstable wire rods at high throughput.

The transport system 310 includes for each of the transport units 320 at least one assigned support unit 720, which, just like a transport unit, can be moved along the transport route 312 under the control of control signals from the control unit 190 according to an individual movement profile. In the example of 1 There is exactly one support unit for each transport unit, with transport units and support units being arranged alternately along the transport route 312.

In 2 an example of a support unit 720 is shown in the area of the bar transfer. The support unit 720 has a support member 730 in the form of a table with a central table top support, which is configured to support a free section DS-F of a wire rod DS picked up by the workpiece receiving device 325 of the transport unit 320 outside the engagement area of the workpiece receiving device from below and by the mechanical to stabilize contact. The engagement area is the area of the workpiece holding device 325 equipped with the components that come into contact with the workpiece. The support point can be at a distance ABA from the engagement area, possibly also directly adjacent to it. With the help of the support unit, the free wire section DS-F can be prevented from bending downwards, and no vibrations can build up in the entire free section due to the support.

A support unit 720 can partly have a similar structure to a transport unit. A transport unit 320 has a base element 322 on which the components of the workpiece receiving device 325 are mounted. Rollers can be mounted on the base element, which roll along guides of the transport route in order to enable smooth movement. The secondary part of the linear motor is also housed on or in the base element.

The support unit 720 has an identical base element 722. Instead of a workpiece receiving device, the e.g. T-shaped support member 730 is provided, which has on its upper side a flat support surface 732 that is relatively wide perpendicular to the longitudinal direction for the free section DS-F of the wire rod DS. The support surface is located slightly below the receiving axis 326 of the workpiece receiving device 325; after setting up, the continuously adjustable level difference corresponds to approximately half the height of the wire rod, so that the wire rod can rest freely with a horizontal orientation and is therefore supported against deflection.

Since a support unit can be moved independently of the assigned transport unit according to an individual movement profile along the transport route 312, the distance AB between a transport unit 320 and the assigned support unit 720 can be continuously adjusted via the control unit and changed in the course of the process. This means that the distance ABA between the workpiece receiving device 325 or its engagement area and the support member 730 can be continuously adjusted.

Based 2 The transfer of a wire rod DS between the rod assembly machine 200 and the bending machine 300 in the area of the rod transfer device 290 will now be explained. This includes a horizontally oscillating gripper 292, which can grip a straight piece of wire DS and transport it horizontally from the area of the cutting device 280 to a transport unit 320 of the transport system. This has a workpiece receiving device 325, which is designed as an elastically flexible clamping device. In a holding frame there is at least one permanently mounted lower clamping element and, opposite, an upper clamping element 327, which is biased in the direction of the opposite fixed clamping element using the spring force of a spring arrangement. An actuating element 329 with a widened head which projects outwards through the holding frame is attached to the upper clamping element 327. An unlocking device 295, which can be controlled via the control unit 190, has a vertically displaceable gripper 297 which can engage the actuating element to transmit tensile forces. The gripper is operated via an electric drive and forms the vertical translational axis (double arrow).

The unlocking unit 295 is part of a loading station 360, at which the straight wire rods DS are loaded into the transport system 310. For this purpose, a transport unit 320 is moved into the loading position shown. The gripper 297 engages the actuating element and with its help pulls the upper clamping element 327 upwards against the force of the spring arrangement 328, so that an unlocked configuration is achieved and the wire rod DS is inserted horizontally into the opened clamping device (tool holder device 325) without overcoming resistance can be. Once the desired position is reached, the clamping device is transferred to a locked configuration by releasing the actuating element 329. The workpiece holding device 325 then holds the workpiece firmly with the force of the spring assembly 328, with the holding forces acting over a relatively long clamping length. Then the transport unit 320 moves with the clamped wire rod along the transport route to a first work station of the bending machine. This is a bending station BS1, which is the first bending station on the transport route.

When loading the wire rod DS, a support unit 720 is arranged between the gripper 292 and the transport unit. The table-shaped support member 730 supports the wire rod when it is inserted into the workpiece receiving device 325 and ensures that the front end of the wire can be inserted coaxially to the receiving axis 326 without colliding with components of the workpiece receiving device before it is closed. After the transport unit has been released, the transport unit and the associated support unit move together, possibly also synchronously, in the direction of the first bending station. If necessary, the distance from the transport unit to the support unit can be adjusted or changed on the way to the first bending station.

Based on 3A until 3D Some basic principles of how a support unit works will now be explained by way of example. 3A shows the transport unit 320 and the associated support unit 720 according to the in connection with 2 explained handover of the baton. The wire rod was inserted into the workpiece receiving device 325 in such a way that the front end section of the wire rod is clamped and the rest of the wire rod protrudes freely, essentially horizontally, at the rear end of the engagement area or on the back (seen in the transport direction 312). In order to prevent the free end from bending downwards due to its own weight, the support unit 720 is arranged at a distance behind the transport unit, which supports the free wire section DS-F approximately in its middle, so that the wire rod rests there on the support surface 732 .

The wire rod should be formed from its rear free end in several bending operations. For this purpose, the transport unit 320 and the support unit 720 first move together in the transport direction 312 to a position behind the first bending station BS1, which is in 3B is shown. For purposes of illustration, this is a bending head with a vertically aligned bending head axis. During the movement of the transport unit and support unit into the in 3B In the position shown, the distance AB between these two units can remain constant, but it can also change. The two units are moved into the area behind the first bending station BS1 in such a way that the free wire section on the side of the support device facing away from the workpiece receiving device can be positioned relative to the bending station so that the first bend B1 can be generated on the wire rod. Here the support unit 720 is still located between the transport unit 320 and the bending head axis. Since the support member supports the wire rod in the vicinity of the intended bending point, the bending head can engage the wire rod exactly at the intended bending point.

Thereafter, in a second bending operation at a downstream second bending station BS2, a second bend B2 is to be created on the wire rod at a distance from the first bend B1. To do this, the transport unit and the support unit move together towards the second bending station ( 3C ). The Distance between transport unit and support unit is reduced by corresponding unequal movement profiles of transport unit and support unit, so that the next bending point B2 is located just behind the support area and can therefore be safely positioned in the engagement area of the second bending unit. Here too, the support unit is still located between the transport unit and the bending head axis.

A third bend B3 should then be created on the wire rod at a distance from the second bend B2, closer to the clamped section. For this purpose, the transport unit 320 and the support unit 720 move into the area of a third bending station BS3 downstream in the transport direction, which is in 3D is shown schematically and which here also has a vertical bending head axis. The support unit moves to a position beyond the bending head unit, so that the bending head BK lies between the transport unit and the support unit and can now attack the wire rod in the immediate vicinity of the clamped section and produce the third bend there. Here the distance AB between the transport unit and the support unit is greater than immediately after the bar was handed over (cf. 3A) .

It can be seen that due to the individual movability of the transport unit 320 and the support unit 720, the free wire end can be supported at any suitable point or also released for access by a bending unit.

The support member of the support unit 3 has a single, essentially flat support surface 732 on which the wire rests, i.e. a lower support surface. 4 shows a variant of a support unit 720 with a support member 730-4, which has a lower support surface and an upper support surface, between which a gap is formed, the height of which corresponds approximately to the height of the wire rod DS in the z direction. The gap is on the in 4 visible side open at the side. Because the wire rod lies in the supported area with only a small amount of height play between the lower and upper support surfaces, vibrations in the vertical direction are even better prevented than with just a lower support surface.

As mentioned above, the workpiece receiving device can be rotated about the receiving axis, for example in order to create a twist in the bent material during the bending operation during rotational draw bending. In the exemplary embodiment of 5 the support member 730-5 comprises a sleeve-shaped support element 732, which is rotatably mounted in a bearing about a horizontal axis and has a single radial receiving slot for the wire rod DS. Due to the rotatable mounting, the support can rotate with the workpiece receiving device, so that the wire section between the workpiece receiving device 325 and the support member 730-5 is not twisted, but the twisting only takes place between the support member and the bending head.

In the exemplary embodiments of 3 and 4 The support units are relatively simple as passive units; they do not have integrated actuators to adjust the geometry of the support unit. However, the height of the support surface in relation to the base element can be manually adjustable when setting up the machine.

In the exemplary embodiments described so far, the wire rod is supported by the support member, but is nevertheless movable laterally and upwards relative to it. It is also possible to design the support member in such a way that the wire rod is mechanically fixed at the support point, which may provide even more reliable protection against deflection and build-up of vibrations. In the exemplary embodiment of 6 The support unit 720 has a support member 730-6 in the form of a clamping device with two clamping jaws, each movable in the vertical direction, which can be switched between a clamping configuration and a release configuration using a suitable actuator (for example electrical or pneumatic). Between the clamping jaws is similar to the embodiment of 4 a laterally open slot is formed, the height of which is adjustable and can be adjusted to the height of the wire rod.

In the exemplary embodiment of the support unit 720 from 7 is the support member 730-7 with the support surface that is wide in the transverse direction, similar to the exemplary embodiment 3 designed, but in contrast to this, the height (in the z-direction) can be adjusted using an integrated actuator. A corresponding height adjustment device can have an actuator that can be actuated electrically or pneumatically, for example, and which can be integrated into the base element, for example. This can be used, for example, to support an already curved section at a different height.

In the exemplary embodiments described so far, the support units 720 can each be moved independently of one another in an individually controlled manner, just like the associated transport units 320, so that, for example, the distance to the transport unit in the transport direction can be adjusted continuously. In the exemplary embodiments of 8A and 8B On the other hand, the support unit 720-8 is integrated into the assigned transport unit 320. The schematically illustrated support unit 720-8 from 8A includes a base support 734, which is in a corresponding bearing of the base element 322 of the transport unit 320 is guided so as to be horizontally displaceable, the direction of displacement being parallel to the direction of travel of the transport unit. The base support carries the support element 730-8, which in the example case 8A can be adjusted in height in relation to the transport unit or the base support by means of another actuator. Thus, as in 8B shown, both the distance between the support member 730-8 and the workpiece holding device 325 of the transport unit 320 can be adjusted continuously (by moving the base support 734) and the height of the support surface of the support member can be adjusted continuously. As a result, the support member can, for example, be brought downwards out of engagement with the wire rod in order to make it possible to make a bend close to the engagement area of the workpiece receiving device 325.

9 shows a variant of a transport unit 320 with integrated support unit 720-9, wherein the support member 730-9 can be moved not only horizontally in the transport direction (distance adjustment) and vertically (height adjustment) using suitable actuators, but also in a transverse direction running horizontally transverse to the transport direction. As a result, the support surface can also be advanced in the transverse direction under the control of the control unit 190, for example in order to support a laterally projecting section in the case of complex bent parts. The support can therefore be moved in space in all three axes and can therefore support the bent part at any point.

As an alternative to the embodiments shown, such functionalities can also be implemented with differently designed support members, for example with a rotatable sleeve or a laterally open longitudinal slot.

Based on 10A , 10B , 11A and 11B Embodiments of support units are described, the support member 730-10 of which can be adjusted in relation to the base element 732 of the support unit. The actuation is carried out using an associated actuation unit 820, which is mechanically coupled to the support unit in such a way that a change in the distance between the actuation unit and the support unit causes an adjustment of the position of the support member. In the exemplary embodiment of 10 the support member 730-10 of the support unit 720 is mounted in a height-adjustable manner within the base element 722. The support unit is assigned an actuation unit 820, which, like the support unit and a transport unit, is guided on guides of the transport route and can be moved individually and independently of the movement state of the assigned support unit via control signals from the control unit 190. The actuation unit 820 can be constructed similarly to a base unit of the support unit or the transport unit and has rollers for rolling on the guides of the transport route and a secondary part of the linear motor. The actuation unit 820 is coupled to the adjustable support member of the support unit 720 via a mechanical coupling device with a rigid coupling rod 840. One end of the coupling rod is articulated on the actuating element, the other end on the foot section of the support member. The bearing points are at different heights such that the support member 730-10 is pushed upwards when the distance between the actuating unit 820 and the support unit 720 decreases and is pulled downwards when the distance increases. This creates an actuator that functions by changing the distance between the support unit and the individually controllable actuation unit.

In the example of 10A and 10B This actuator achieves a height adjustment of the support member 730-10 or its support surface. In the exemplary embodiment of 11A and 11B a support member 730-11 in the form of a clamping device is adjusted via the distance adjustment between the actuation unit 820 and the support unit 720. Via the mechanical coupling device 840, the upper clamping jaw of the clamping unit can be moved in the direction of the lower clamping jaw (in the clamping position) when the distance between the support unit and the actuating unit increases ( 11 B) . In these variants, the adjustment of the distance between the support unit and the associated actuation unit serves as an actuator for actuating a movable support member or a movable component of a support member.

Based on 12A until 12D A variant of a transport unit 320 with an integrated support unit will now be described in different phases of a bending process. The support member 730-12 of the support unit is designed here as a wire guide with a laterally open, slot-shaped passage opening for the wire rod DS to be supported or guided. The support member is movably guided parallel to the receiving axis 326 of the workpiece receiving device 325 using linear guides. A spring arrangement 733, which is arranged between the workpiece receiving device and the support member, biases the support member into an end position or starting position that is remote from the workpiece receiving device 325 and defined by a stop.

12A shows this transport unit 320 with an integrated, spring-loaded support member immediately after loading with a wire rod DS, which is held clamped in the workpiece receiving device. The free wire section runs through one Guide slot in the wire guide, which supports the free wire section approximately in the middle against downward bending. As a result, the protruding free end of the wire rod can be threaded reliably and without the risk of collision into the bending head BK of the bending unit. In the example case, this is designed with a horizontal bending head axis.

In order to introduce a first bend B1 on the wire rod DS, the in 12B The position shown is reached, in which the intended bending point is in the bending head and the first bend B1 can be introduced. The relative movement can be realized in different ways. For example, the transport unit 320 can be moved to the right in the illustration. Alternatively, it can also be the case that the bending head is moved to the left. It is also conceivable that both the transport unit and the bending head are moved relative to one another in order to adjust the arrangement to the first bending position. When the support member or the wire guide 730-12 approaches the bending head, it abuts against a stop of the bending head and, as it approaches further, is pressed against the force of the spring arrangement in the direction of the workpiece receiving device. A grid 734 on the guide elements prevents the wire guide or the support member 730-12 from jumping back into its starting position or end position when the external pressure force is no longer present.

To produce the second bend B2, the distance between the transport unit 320 and the bending head or bending head axis is reduced in accordance with the distance between the two bends, with the spring arrangement 733 being further compressed. Here too, the grid on the guides ensures that it does not jump back. Then, in an analogous manner, the location for the third bend B3 is brought into the engagement area of the bending head by further reducing the distance between the transport unit and the bending head and the third bend B3 is generated. Here the spring arrangement is compressed even further; the wire guide is prevented from springing back by means of a locking mechanism.

When the finished bent part is removed, the clamping function of the workpiece holding device 325 of the transport unit and the grid are released, so that the wire guide or the support member 730-12 can jump back to its front end position after the bent part has been removed. The transport unit is then ready to receive the next wire rod.

An advantage of this solution is that the free length of the wire rod or the developing bent part can always be guided to the greatest possible length during transport by means of the transport unit.

The transport system 310 with the individually controllable transport units 320 enables an optimal spatial distribution of bending stations with uneven distances along the transport route. As a result, an overall compact structure with a relatively small space requirement can be achieved. Productivity can also be increased by the transport system 310 by shortening the overall required transport times (non-productive times), so that more time (main time) remains for the bending operations. For example, a bent part can be transported to the subsequent bending station more quickly after a relatively long bending operation than in the case of a relatively short bending operation. In addition, some transport units may be moved while other transport units remain stationary at their bending stations because the bending operation has not yet been completed. Finally, the return transport of a transport unit between the unloading station 380 and the loading station 360 can take place very quickly, so that there is no waiting time for the productive bending operations. Compared to systems with fixed timing, such as a rotary transport system, variable timing results in significant practical and economic advantages. Thanks to the assigned support units 720, the individual operations systematically run smoothly without any problems, even at the highest processing and transport speeds and accelerations, as well as when processing mechanically unstable wires.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102020212558 A1 [0003, 0058]

Claims (17)

Bending machine (300) for producing complex bent parts from straight wire rods (DS), comprising: a computer numerical control unit (190); a transport system (310) for transporting successive wire rods along a transport route (312), the transport system having a plurality of transport units (320), each transport unit (320) having a workpiece receiving device (325) for receiving a single wire rod (DS) and via Control signals from the control unit (190) can be moved along the transport route (312); a plurality of work stations which are arranged along the transport route (312), at least two of the work stations being designed as bending stations (BS1, BS2, BS3), characterized in that the transport system (310) for a number of the transport units (320) along at least one the transport path has a movable support unit (720), which comprises a support member (730) which is configured to hold a free section (DS-F) of a wire rod (DS) picked up by the workpiece receiving device (325) of the transport unit outside an engagement area of the workpiece receiving device ( 325) for mechanical stabilization of the free section. Bending machine (300). Claim 1 , characterized in that a distance (ABA) between the workpiece receiving device (325) and the support member (730) is adjustable, preferably continuously adjustable, via control signals from the control unit (190). Bending machine (300). Claim 1 or 2 , characterized in that a support unit has an integrated actuator, which can be controlled via control signals from the control unit and is configured to cause a movement of the support member between different working positions. Bending machine (300) according to one of the preceding claims, characterized in that a transport unit is assigned at least one support unit which has a support member which can be adjusted in height and/or in an axial direction and/or in a transverse direction via control signals from the control unit. Bending machine (300) according to one of the preceding claims, characterized in that at least one support unit is designed as an individually controllable support unit (720), which is independent of an assigned transport unit (320) via control signals from the control unit (190) along the transport route (312). is movable, preferably several or all support units being designed as individually controllable support units. Bending machine (300). Claim 5 , characterized in that a transport unit (320) has a base element (322) on which components of the workpiece receiving device (325) are mounted, and that the individually controllable support units (720) have a base element (722) which is essentially identical in construction to the base element of the transport unit. have that the support member (730) carries. Bending machine (300). Claim 5 or 6 , characterized in that an individually controllable support unit (720) has a support member (730) which has a support surface which can be adjusted in height by means of a height adjustment device via control signals from the control unit (190). Bending machine (300). Claim 5 , 6 or 7 , characterized in that an individually controllable support unit or an integrated support unit has an adjusting device for adjusting a position of the support member (730) in relation to a base element of the support unit or the transport unit, that the support unit has an individually controllable actuating unit (820) which can be moved along the transport route ) is assigned, and that the actuating unit is mechanically coupled to the adjusting device of the support unit via a mechanical coupling device (840) in such a way that the adjusting device can be actuated by changing the distance between the actuating unit (820) and the support unit (720). Bending machine (300). Claim 5 , 6 , 7 or 8th , characterized in that transport units (320) and support units (720) are arranged alternately along the transport route (312) in such a way that a support unit (720) is behind a leading transport unit (320) in the transport direction and at the same time in front of a next, lagging transport unit in the transport direction (720) is arranged. Bending machine (300) according to one of the preceding claims, characterized in that at least one transport unit (320) has an integrated support unit (720), wherein preferably a base element (322) of the transport unit carries components of the workpiece receiving device (325) and the support member (730- 10, 720-12) of the support unit is mounted movably relative to the workpiece receiving device (325). Bending machine (300). Claim 10 , characterized in that the support member is adjustable in relation to the receiving axis (326) of the workpiece receiving device (325) parallel to the receiving axis, wherein preferably the supporting member is additionally adjustable in at least one feed direction which runs perpendicular to the receiving axis of the workpiece receiving device. Bending machine (300) according to one of the preceding claims, characterized in that the support member (730) has a support surface (732) which is elongated transversely to the transport route, a length of the support surface measured perpendicular to the transport route (312) being at least 50 mm. Bending machine (300) according to one of the preceding claims, characterized in that the support member has a lower support surface and an upper support surface arranged at a height distance above the lower support surface, wherein a gap formed between the support surfaces has a height which is essentially the height of the Wire rod corresponds in such a way that the wire rod fits into the space with little height play and can be moved horizontally. Bending machine (300) according to one of the preceding claims, characterized in that a support member (730-5) is rotatably mounted about a horizontal axis of rotation, the support member preferably being designed as a passively rotatable support member, which, if necessary, has a rotating about its axis Wire rod is rotated. Bending machine (300) according to one of the preceding claims, characterized in that the transport unit has a support member (730) which is movably guided relative to a base element (322) of the transport unit along a guide parallel to the receiving axis of the workpiece receiving device (325) and by means of a spring arrangement (733) is spring-loaded in the direction of an end position remote from the workpiece receiving device. Bending machine (300) according to one of the preceding claims, characterized by at least one of the following features: the transport system is designed such that each of the transport units can be moved along the transport route (312) via control signals from the control unit (190) according to an individual movement profile; at least one bending station (BS2) has a bending unit (340-2), which is configured as a rotary draw bending unit. Wire processing system (100) for producing complex bent parts from wire (D), comprising: a rod assembly machine (200) for producing straight wire rods (DS) of predeterminable length from wire material; a bending machine (300) connected downstream of the rod assembly system (200) for producing complex bent parts from the straight wire rods, the bending machine (300) according to one of Claims 1 until 16 is designed.

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