Method for manufacturing a shaped piece from a profiled element and wire processing machine

Abstract

In a method for manufacturing shaped parts from wire, a wire (W) is drawn from a wire store and fed to a wire processing machine (100). The wire is straightened in the wire processing machine (100) and shaped parts having a predefinable wire length are separated from the straightened wire by means of a cutting device (300). In order to separate a shaped part from the wire being fed, the wire (W) is first notched in at least one notching operation from both mutually opposite sides at a cutting position provided for the separation by means of a notching tool in such a way that a tapering wire cross section remains between the mutually opposite notches at the cutting position. Subsequently, the notched wire is cut in the region of the tapering wire cross section at the cutting position in a dividing operation by two dividing tools acting on opposite sides of the wire and fed synchronously transversely, in particular perpendicularly, to the wire axis in opposite feed directions until the wire material is severed at the cutting position (TP). A wire processing machine constructed for carrying out the method is also described.

Description

TECHNICAL FIELD

[0001] The present invention relates to a method and a wire processing machine for manufacturing shaped parts from wire. BACKGROUND

[0002] The shaped parts can be straight shaped parts, also referred to as "wire rods" in this application, or two- or three-dimensionally curved curved parts composed of wire, which have one or more curved sections between the wire ends.

[0003] Increasingly, vehicles with fully electric or partially electric drive are being offered on the market. The vehicles mostly have an energy storage system with a plurality of battery modules. The electrical energy has to be transmitted between the individual battery modules. For this purpose, insulated and curved copper or aluminum wires, also referred to as "busbars", are used. The busbars are usually manufactured using a correspondingly shaped flat material, for example a copper or aluminum flat wire with a flat, rectangular cross section. The flat material can be wrapped in sections or continuously with an electrically insulating insulation layer. For the manufactured busbar, the end sections are typically bare metal, i.e. without an insulation layer, and are, for example, screwed, clamped or welded in the region of the end sections in the installation environment provided for them. In order to ensure a reliable contact, the end sections of the wire should match the corresponding contact elements as well as possible. In order to make the reworking of the wire ends as superfluous as possible, the wire ends should be shaped immediately after the manufacture in a wire processing machine in such a way that a good match to the installation environment is produced.

[0004] Patent document DE 10 2018 114 579 B3 describes the field of application of profiled wire rods and a method and a device which can be used for manufacturing wire rods in order to separate the wire without burrs. Described here is the manufacture of individual winding elements (plug-in coils, so-called "Hairpins") in the manufacture of electric motors for traction drives, which winding elements are further processed into complete stator windings in a further process. In order to achieve a higher efficiency of the electric motor for reasons of a higher filling degree, a transition from round wire to wire with a rectangular cross section takes place in the Hairpin technology. In the context of the manufacture of plug-in coils, corresponding wire sections are dimensioned cut out of the continuous material and separated, which are welded to one another after being positioned on the stator. In order to be able to reliably separate the wire without burrs with simple design means, a method is proposed in which, first of all, in a first profiling step, the (burr-free) profiling of the wire takes place at a wire longitudinal position by moving two profiling sections of a first profiling unit, which are opposite one another in a first plane, towards one another along a first movement axis. Here, the wire cross section is tapered in this first profiling step from two opposite sides, for example from two narrow sides. When profiling the wire, the profiling sections of the first profiling unit are always spaced apart from one another, so that the tapered wire cross section is retained. Subsequently, in a second profiling step, the profiling of the wire takes place at the same wire longitudinal position by moving two profiling sections of a second profiling unit, which are opposite one another in a second plane, towards one another along a second movement axis. Here, the already tapered wire cross section is tapered in this second profiling step from the other two opposite sides, for example from two wide sides. When profiling the wire, the profiling sections of the second profiling unit are always spaced apart from one another, so that the already tapered wire cross section is retained in further tapered form. As a result, a material tab is left at the wire longitudinal position, which is arranged offset inwards with respect to the original cross-sectional shape of the wire. At this point in time, the wire sections arranged before and after the wire longitudinal position (of the set division site) are still connected to one another by the material tab. Subsequently, i.e. after the second profiling step, the pulling apart of the wire takes place at the same wire longitudinal position by applying a pulling force (acting at least partially in the wire longitudinal direction) to the wire. As a result, the wire is separated at the wire longitudinal position. SUMMARY

[0005] It is the task of the present application to provide a method and a wire processing machine for manufacturing profiled shaped parts from wire, which allow the manufacture of profiled shaped parts with wire ends which are very well defined in terms of geometry.

[0006] To solve this task, the application provides a method having the features of claim 1. Furthermore, a wire processing machine having the features of claim 16 is provided. Advantageous refinements are specified in the dependent claims. The original wording of all claims is incorporated into the description by reference.

[0007] The method and the wire processing machine serve to produce shaped parts from wire. In the context of the present application, the concept "shaped part" denotes a semi-finished or finished product made from wire, which has a desired wire length for the purpose of the application and a wire end that is as well defined as possible. The wire end should in particular have a geometry that is suitable for the purpose of the application, for example with a chamfer at the wire end. The raw material wire is a long, more or less bendable metal piece, which has a suitable cross-sectional shape. A wire with a circular cross-section is referred to as round wire. There are also wires with other cross-sectional shapes, for example flat wires, quadrangular wires or profiled wires.

[0008] The shaped part can be a straight shaped part, which is also referred to as "wire rod" in the present application, or a two- or three-dimensionally curved bent part composed of wire, which has one or more bends between the wire ends. Wire processing machines for producing straight shaped wire rods are sometimes referred to as "rod formers", and in wire processing machines for producing curved shaped parts, the term "bender" is often used. The shaped part can also be a spring, for example a helical spring, which can be produced from wire by means of a spring machine.

[0009] In the method, wire is continuously or intermittently drawn off from a wire store and fed to the wire processing machine in sections. In the wire processing machine, the wire is straightened. Then, the shaped part, a wire section with a wire length that can be predefined, and the desired shape, the outer shape, are separated from the wire.

[0010] Between straightening and severing, one or more bending operations can be carried out in order to produce a shaped part that has one or more bends, a bent part. As an alternative, a straight wire section, a so-called wire rod, can be separated from the wire that has been straightened.

[0011] In order to separate a wire rod having a desired length from the wire that is fed, a plurality of functionally different operations are carried out one after the other in time.

[0012] First, the wire material is notched in at least one notching operation by means of a notching tool at a severing position or severing site provided for the severing, from two mutually opposite sides in such a way that a section with a tapering wire cross-section remains between the mutually opposite notches at the severing position.

[0013] The term "notch" generally means herein a cut in the wire material produced by material displacement and / or material removal. The size and shape of the notch is determined by the embedding profile of the notching tool into the wire material and by the penetration depth thereof.

[0014] The notching operation is preferably a forming operation in which the notch is produced by material displacement or material forming only, without material removal. Thus, the notch is preferably produced by conventional shaping of the wire material in the region of the dividing location.

[0015] For example, the notching tool can have a more or less tapering wedge shape. The notch produced thereby then mostly forms a substantially V-shaped, i.e. wedge-shaped or tapering cut in the wire material. However, the shape of the notch is not limited to a V-shape. The notch can also be more or less rounded in the region of the notch bottom. A notch in the form of a cut which is substantially cylindrical or a notching with a U-shape can also be produced.

[0016] The notching tool is preferably synchronously fed along mutually opposite feed directions perpendicular to the wire axis during the notching operation. To this end, the notching mechanism can be configured accordingly for the synchronous feeding of the notching tool. What can be achieved thereby is that, ideally, no resultant transverse force acts on the wire during notching and that the wire is not bent as a whole by the notching.

[0017] The feed movement of the notching tool is preferably controlled in such a way that the penetration depth of the notching tool is at least 10% of the extent of the wire material which is not notched along the first direction, preferably in the range of 20% to 50% of this extent. Thus, in the tapering wire section or in the region of the narrowing of the thinner web, a respective residual width (perpendicular to the wire longitudinal direction) can be retained which is in the range of 90% or less of the original diameter along the first direction, in particular in the range of 50% to 80% of this original diameter. Thus, according to the experience of the inventor, a particularly good compromise between good preparation for the subsequent cutting operation and at the same time sufficient stability in the region of the tapering wire cross section can be achieved.

[0018] As an alternative thereto, the notch can be produced in the case of material removal, for example by means of milling or punching.

[0019] It is important that, during the notching operation, a wire section with a tapering wire cross-section remains in the region of the cutting position inside the wire. Thus, at the cutting position, the wire material is not completely severed, but the sections before and after the notch remain connected to one another integrally by means of the tapering wire material tab. In the notching operation by means of forming, a strengthening of the wire material, i.e. an increase in the mechanical strength of the wire material due to plastic deformation, is usually carried out in the region of the tapering wire cross-section.

[0020] The dividing operation is carried out after the end of the notching operation. By means of the dividing operation, the notched wire is divided at the cutting position in the region of the tapering wire cross-section by means of two dividing tools acting on opposite sides of the wire and fed synchronously in mutually opposite feed directions perpendicular to the wire axis until the wire material is severed at the cutting position.

[0021] The concept "perpendicular" is to be understood here as meaning that the direction either runs exactly perpendicular to the wire axis (at an angle of 90°) or deviates from the exactly orthogonal direction by one or a few degrees, for example by a maximum of 5°. It is decisive that the feed is sought to be perpendicular within the range of technical tolerances. The concept "synchronously" accordingly means contemporaneity within the range of reasonable technical tolerances caused by control and hardware.

[0022] In the present application, the concept "dividing" means, in accordance with DIN standard DIN 8588, that the wire is completely divided into two parts at the cutting position. Here, the division is carried out in a mechanical manner without the formation of chips. The dividing operation is thus a kind of cutting operation in which the wire is not subjected to chip-forming machining, but is divided without chips (without material removal or without the production of chips). The dividing tool is thus a chipless cutting tool.

[0023] In a wire processing machine for producing shaped parts, for example wire rods or bent parts, from wire material, in order to separate the shaped parts from the wire material which has been straightened or is straightened after one or more dimensional bending operations, a dividing device is provided at a cutting position provided for the cutting, which has a notching mechanism and a dividing mechanism which can be actuated in time after the notching mechanism. The dividing device is set up to carry out the method.

[0024] The method can be carried out in such a way that, after straightening, a straight wire rod with a predefined length is separated from the straightened wire without an intervening bending operation. As an alternative, it is also possible to produce one or more bends in the straightened wire after straightening and before cutting, so that the shaped part is a bent part.

[0025] A wire processing machine adapted to carry out the method and adjusted has a dividing mechanism which, in the adjusted state ready for operation, has two dividing tools between which the wire can pass through, wherein the dividing tools can be fed synchronously in mutually opposite directions perpendicular to the wire axis for carrying out a dividing operation, and wherein the dividing mechanism is configured in such a way that a slotted wire can be cut at a cutting position in the region of a tapering wire cross section by feeding the dividing tools synchronously in mutually opposite directions perpendicular to the wire axis in a dividing operation until the wire material is severed at the cutting position.

[0026] Before starting the feed of the dividing tools, there is generally no contact between the dividing tools and the wire, so that the dividing tools do not hold the wire. The dividing tools then come into contact with the wire and mechanically act on the wire material during the feed. In theory, the dividing tools would simultaneously contact the wire with the same force. In practice, this cannot always be ensured due to technical tolerances. In order to avoid the wire tilting out of the desired wire orientation when the oppositely acting dividing tools embed differently, an adjustable hold-down device can be provided before and after the cutting position, which temporarily holds the wire in the desired orientation in time before the dividing operation and, if necessary, also at the beginning of the dividing operation.

[0027] By the synchronous two-sided embedding of the dividing tools on opposite sides of the wire material, an overall bending of the end section can be avoided, so that the end section also assumes a straight shape existing without transverse forces at the time of and after the dividing operation. The shaped wire rod produced according to the method can generally be used for the intended application without subsequent processing. Further processing can thus be more economical than before.

[0028] Within the scope of the invention there are different options to design the slitting operation and the dividing operation and to coordinate them with each other.

[0029] According to an expansion, the dividing operation in the form of a cutting operation is carried out after the end of the slitting operation. The wire is thus cut at the cutting position by a cutting process which is a special type of non-cutting division. Correspondingly, the dividing mechanism is configured as a cutting mechanism and the dividing tools are designed as cutting tools. The cutting tools have at least one cutting edge on which a cutting edge is configured, which is preferably a straight cutting edge here.

[0030] The division is preferably carried out by means of a bite cut or a shear cut, which is explained in detail below.

[0031] In one variant of the cutting operation, the slotted wire material is slit at the region of the tapering wire cross section, i.e. at the parting location, by means of a bite cut. This is done in such a way that the wire material is held in place in the region between the two wedge-shaped cutting edges of the cutting tool and the cutting tool or the wedge-shaped cutting edges are moved towards each other relative to each other until the wire material is severed at the parting location. Prior to the start of the feed of the cutting edges, there is usually no contact between the cutting edges and the wire, so that the wire is not held by the cutting edges. The cutting edges then come into contact with the wire and are pressed into the wire material during the feed.

[0032] The manufacturing method "bite cut" is a variant of wedge cutting and belongs to the following parting methods according to DIN 8588, which divide the workpiece to be parted without producing chips. The cutting edges formed on the wedge-shaped cutting edges are here in one common plane. The relative movement can be guided in such a way that the cutting edges come into contact with each other at the end of the cutting operation. The feed movement can also be ended in advance if the flat material has already been severed before contact occurs between the cutting edges. In the case of a bite cut, the wedge-shaped cutting edges press into the wire material to be divided from two opposite sides. It has been shown that the formation of sharp burrs at or on the end of the wire material can be avoided by this cutting method. It can be said that the cutting operation enables the wire material to be cut substantially burr-free.

[0033] By the simultaneous, two-sided embedding of the wedge-shaped cutting edges of the cutting tool on the opposite sides of the wire material, the overall bending of the end section can be avoided, so that the end section remains in the straight shape existing without transverse forces at the time of the cutting operation and thereafter. The wire rod thus shaped can usually be used without reworking for the intended application.

[0034] This two-stage process variant "slitting and bite cut" precisely causes the parting of the wire section before and after the intended parting location without having to introduce a pulling force acting in the longitudinal direction of the wire from the outside. In contrast to the conventional pulling apart, it is thus possible to dispense with the corresponding device for pulling apart. Since the pulling force acting in the longitudinal direction of the wire has to be added in order to carry out the pulling apart, it cannot be ruled out that the length of the wire rod to be parted thereby changes slightly, so that a length error caused by the pulling force can occur. This error source is excluded in the method according to the application claimed, so that shaped parts, for example wire rods, having a precisely defined length between the wire ends are systematically manufactured.

[0035] Furthermore, the geometry of the wire end produced at the splitting location can be precisely defined by the scoring tool used in the scoring operation and / or the effective geometry of the wedge-shaped cutting edge used in the cutting operation. This applies especially when the scoring operation is a purely forming operation, since the scoring tool and the wedge-shaped cutting edge do not act by pulling and / or material removal, but only by plastic material displacement, so that their action profile is at least partially pressed into the wire material or the wire end. Thus, it is possible to systematically produce formed wire pieces (straight or curved) with narrow length tolerances and with wire ends that are very well defined in terms of geometry.

[0036] The two-stage process can also be described as follows, such that a scoring operation is provided before the cutting operation, in which the wire material is cut at the splitting location by means of "bite cutting" in the cutting operation, and in which the wire material is prepared for the bite cutting in the area of the defined splitting location by the scoring operation. Especially when the preparatory scoring operation is carried out by means of a forming method for producing a tapering wire cross-section, the wire material is strengthened in the area where it is later to be cut by a wedge-shaped cutting edge. Thus, the wedge-shaped cutting edge does not come up against untreated wire material, but against wire material that has been pre-treated and which, by the scoring operation, is strengthened and thus can be reliably and more cleanly split than untreated wire material, which is softer in comparison to the tapering wire cross-section. This effect also contributes to the clean geometric definition of the wire end.

[0037] According to an expansion, the notching tools are arranged or can be arranged opposite one another along a first direction and can be fed parallel to the first direction, while the wedge-shaped cutting edges of the cutting tools are arranged or can be arranged opposite one another along a second direction and can be fed parallel to the second direction, wherein the first and second directions run perpendicularly to one another. Thus, the notching operation and the cutting operation act on the wire material along directions orthogonal to one another. Thereby, a tapering structure of the wire material can be produced at the wire end along two mutually perpendicular directions. The cutting face or fracture face produced at the snap cut is ultimately inside the envelope surface of the initial wire from all directions, so that no burr remains outside this envelope surface. The orthogonal acting directions of the notching operation and the cutting operation can advantageously be utilized in all workpiece cross sections, thus also in circular wires. If an initial workpiece having a rectangular cross section is to be divided, the wire material should be oriented relative to the first and second directions such that the first direction is oriented perpendicular to a first pair of flat sides, while the second direction is oriented perpendicular to a second pair of parallel sides. Thus, the notching tools and later the cutting tools can embed into the wire material over the entire width of the contact face, respectively, substantially simultaneously, thereby producing the geometrically defined wire end particularly well.

[0038] Before the cutting tool is later embedded on the wide side, the narrow side is usually notched first. Thus, the notching geometry is largely preserved at the cut. However, the reverse order (notching on the wide side, cutting on the narrow side) is also possible.

[0039] It is possible that the notching tools are in a first plane oriented perpendicular to the wire passing direction and the wedge-shaped cutting edges of the cutting tools of the cutting mechanism are in a second plane perpendicular to the wire passing direction, which second plane is offset from the first plane along the wire passing direction. With this arrangement, it is possible to produce a structural freedom for the design of the cutting mechanism and the notching mechanism. However, in order to ensure that the cutting operation embeds sufficiently precisely at the location of the previously notched recess, the material transport between the two planes must take place with high precision.

[0040] In a preferred embodiment, the wire material is not moved along the wire longitudinal direction between the notching operation and the cutting operation, so that the notching operation and the cutting operation are carried out in the same plane. This can be solved structurally in that the notching tool of the notching mechanism, more precisely the end of the notching tool which acts, and the cutting edge of the cutting tool or cutting mechanism are arranged in a common plane. In this embodiment, the notching and cutting can be precisely carried out at the prescribed split location without depending on the movement state of the wire, so that no axial offset occurs between the notch and the split location on the wire. The shape of the wire end can be precisely predefined by the tool shape of the notching tool and the cutting edge.

[0041] There are different possibilities for the design of the notching tool. In a preferred embodiment, the notching tool is configured as a roof-shaped notching wedge with a sharp or rounded tip region, i.e. also substantially wedge-shaped. It can be advantageous if the wedge-shaped notching tool is designed as a symmetrical wedge. The term "symmetrical wedge" means here a wedge whose wedge faces or wedge side walls are substantially inclined symmetrically to the feed direction. Thus, a symmetrical material displacement on both sides can be achieved during notching. If the wire end of the shaped part is to be designed differently, for example, an asymmetrical wedge shape is also possible.

[0042] The wedge angle, i.e. the angle enclosed by the substantially flat wedge faces, can be selected depending on the application. In many embodiments, the wedge angle enclosed by the wedge faces is in the range of 90° to 140°, i.e. it is obtuse. With this geometry, for example, a precisely produced chamfer on the wire end can be achieved.

[0043] As an alternative or in addition, it can be provided that the wedge-shaped cutting edge of the cutting tool has a wedge angle in the range of 90° to 140°. In particular, it can be arranged so that the wedge angle of the notching wedge substantially coincides with the wedge angle on the wedge-shaped cutting edge. It is thereby possible to produce a uniformly inclined chamfer on all four sides, for example, on a wire material having a rectangular cross section. The wedge-shaped cutting edge can be configured symmetrically with respect to the feed direction, if necessary also asymmetrically.

[0044] The notching tool and / or the wedge-shaped cutting edge can each have its own drive which causes the feed movement. Preferably, however, the notching mechanism has only one unique drive which is coupled to both notching tools for synchronous feed. This is a cost-advantageous solution on the one hand, since one drive can be saved. On the other hand, the precision of the mutually opposite feed of the notching tools during the notching operation can thereby be ensured structurally.

[0045] It is similarly possible to provide for the cutting mechanism to have only one unique drive, which is coupled to both wedge-shaped cutting edges for synchronized feeding.

[0046] In some embodiments, the drive of the grooving mechanism drives a crankshaft, which drives two linearly movable sliders, which are able to move in opposite directions, by means of two connecting rods, which carry the grooving tools on their ends facing the workpiece. A similar solution can be provided in the cutting mechanism.

[0047] An alternative solution provides for only one unique drive to be provided for controlling the movement of the grooving tool of the grooving mechanism and the wedge-shaped cutting edge of the cutting mechanism. This drive can drive a cam disk with control cams, which are designed such that, when the cam disk is rotated about its axis of rotation at the correct tempo and in the correct direction of rotation and to the correct extent, it alternately first feeds and then pulls back the grooving tool and, thereafter, is able to feed and then pull back the cutting tool with the wedge-shaped cutting edge in the direction of the workpiece. In order to adapt this variant to different wire geometries, it is possible to replace the cam disk with a cam disk having other control cams.

[0048] The cutting device or its components can be mounted on the frame of the wire processing machine in a stationary manner on the machine. In some embodiments, however, it is provided that the cutting device is supported floatingly parallel to the direction of passage of the wire or parallel to the passage axis. Thus, the cutting device can compensate for the resultant forces in the longitudinal direction of the wire that occur during grooving and / or dividing by means of a floating movement parallel to the direction of passage of the wire. It has been shown that, inter alia, it is thereby possible to achieve that the wire geometry at the wire end is particularly precisely predetermined and that the wire piece is not bent, but straight, in the vicinity of the wire end. It is also possible that the cutting device can be moved parallel to the direction of passage of the wire by means of a drive, for example a servo motor.

[0049] In wire processing machines in which shaped formed parts in the form of bent parts are to be produced, corresponding bending devices with one or more bending tools are provided. The bending devices are arranged and constructed in such a way that, after all the prescribed bending operations have been completed, a cut is made between the bent formed part and the delivered section of wire that has not yet been bent. Various structural possibilities exist for this. The bending device can be arranged behind the cutting device along the direction of passage of the material, so that there is an axial spacing between the two. It is also possible for the bending device or its tools to be in the same plane as the cutting device. The tools of the bending device can thus act in the cutting plane. The produced formed parts can be sorted, for example, into good parts and problematic parts by means of a sorting device and then transported away. This is also possible in a similar way in wire processing machines that are configured as bar formers for producing straight wire bars with defined wire ends.

[0050] In contrast, some embodiments are distinguished by the provision of a transport gripper for grasping the wire section to be separated before the notching operation and / or the cutting operation in order to transport the separated wire section to a working station arranged behind after the cutting operation has ended. The transport gripper can be guided in such a way that it can be moved linearly parallel to the wire transport axis and be activated during the notching operation and / or during the cutting operation in such a way that forces and torques are reduced, so that the transport gripper can follow the length-compensating movement of the wire section to be separated floatingly during the notching operation and / or during the cutting operation. It is thus ensured for the device for continued transport of the formed part that has been dimensionally cut that no counterforces act on the cutting process from the formed part that has already been grasped.

[0051] In order to ensure in addition that the cutting operation is not negatively influenced by tensile forces acting parallel to the wire longitudinal axis, the transport device is preferably configured in such a way that the transport movement only begins after the cutting operation has ended, that is, only when the formed part to be separated has also actually been separated from the delivered wire. In contrast, the grasping of the formed part to be separated can already take place before the wire is completely severed.

[0052] Other developments combine the method steps, that is, the notching and the subsequent cutting. It is thus possible, among other things, to solve the following problems.

[0053] In order to reliably join hairpins into a stator lamination stack with slot insulation paper, as far as possible burr-free, chamfered end portions on the hairpin legs are preferred. In the process of the bite cut or in the process of the pull-apart, depending on the wedge angle of the slotting and cutting tool, a more or less pointed pyramid shape can be produced. After the insertion of the hairpins into the stator lamination stack and the crossing over in the stator lamination stack, the hairpin end portions are usually contacted by means of a welding process. Therefore, the pointed end portions of the hairpin legs are often recut before the welding process, in order to produce perpendicular surfaces which can be better welded to one another.

[0054] According to an expansion of the application, the recutting can be dispensed with without quality loss.

[0055] In this expansion, the dividing operation is designed as a shearing operation in which the wire is divided at the dividing position by shearing by holding the wire between two dividing tools which are formed as shearing tools, the dividing tools acting on different axial sides of the dividing position and moving synchronously in mutually opposite feed directions perpendicular to the wire axis until the wire material is severed at the dividing position.

[0056] The dividing mechanism is correspondingly designed as a shearing mechanism which, in the adjusted ready-to-operate state, is configured for the shearing operation.

[0057] It is known that in mechanical devices a shearing arises from the action of force couples which are arranged offset. The forces are introduced by the shearing tools in which one shearing tool acts before the dividing position in the wire longitudinal direction and the other shearing tool acts after the dividing position in the wire longitudinal direction on opposite sides with respect to the wire axis. The forces thus act on the wire at axially offset positions between which the dividing position is located. There, under correct method control, a comparatively smooth shear plane is produced on the free wire end which is oriented perpendicular to the wire longitudinal axis.

[0058] The shearing tools can have non-cutting, planarly extending working surfaces and support planarly and material-protecting in the vicinity of the dividing position on the axially and diametrically opposite sides of the wire and introduce forces when the shearing tools are fed mutually opposite which, by shearing at the dividing position, cause the dividing result.

[0059] It is preferred to use shearing tools with cutting edges. In other words, the cutting operation can also be designed as a shearing cutting operation.

[0060] Especially in view of such above outlined applications in the manufacture of hairpins, an extension of the shearing cutting operation is proposed which enables a simplification of the entire process and which makes subsequent processes, such as trimming of the leg ends, superfluous.

[0061] In this variant, the separation immediately after the grooving is carried out by shearing cutting. According to DIN 8588, the shearing cutting or shearing is a separation of material by two cutting edges which move past each other next to each other. In the context of the present application, it is applied according to the modified definition that the material is separated when sheared by two cutting edges which can move past each other next to each other, but not necessarily always. Unlike in the case of the nibbling cutting, the cutting edges are not in a common plane, but in planes which are slightly axially offset relative to each other. For relatively soft materials, such as for example copper, the cutting edges must generally move past each other next to each other in order to achieve the cleaving. For harder, more brittle materials, such as for example spring steel, it is possible that the material breaks before the cutting edges hit each other and thus the cleaving is completed. The feed can then be stopped.

[0062] For the shearing cutting, the shearing tool is equipped with cutting edges like scissors, which move past each other next to each other in planes which are offset relative to each other during the shearing process and, if necessary, move past each other next to each other. Here, the material is sheared due to the shearing force. Here, the cutting edges move parallel to the cutting plane between them, there is a narrow shearing gap between the cutting edges. The cutting plane is positioned at the cleaving position. By means of the shearing cutting it is possible that the end face of the separated wire is essentially in a plane perpendicular to the wire longitudinal axis at the cleaving position. The end section of the wire can have the shape of a truncated pyramid. A flat, macroscopically flat end face can be advantageous especially in cases where the wire should be connected to other components face- wise, for example by welding, in subsequent processing steps.

[0063] Thereby, especially a cleaving method is provided in which a chamfered wire end is produced in order to easily engage into a stator lamination stack and in addition a straight surface is retained on the wire end, which is necessary for a process-reliable welding. Thereby, a subsequent process "re-cleaving of the hairpin end" can be dispensed with, which reduces the manufacturing costs in the manufacture of the stator.

[0064] As a preparation for the shearing operation, in particular the shearing cutting operation, it has proven advantageous if the wire is notched beforehand on four mutually pairwise opposite sides. For a wire having a rectangular cross section, the notches are preferably on all the essentially flat sides. To this end, the notching mechanism of the respective embodiment is configured such that, in a notching operation provided before the shearing operation, the wire is first notched on two sides opposite along a first direction and thereafter notched on two sides opposite along a second direction, wherein the first and second directions run perpendicularly to one another.

[0065] For the notching operation and the dividing operation, different tools can be used, which are designed specifically for the respective operation. However, this is not mandatory. In some embodiments, a combined tool is used for the notching operation and the cutting operation on opposite sides of the wire, which has (at least) an integrated notching tool and an integrated dividing tool, which are fed pairwise synchronously in time one after the other along two mutually perpendicular directions. Here, the notching function and the dividing function (for example by bite cutting or by shearing cutting) are integrated in one unique tool. The tool-carrying assembly of the wire processing machine must then have the required degrees of freedom of movement, which allow the feed along the orthogonal feed directions.

[0066] A combined tool can be designed, for example, for the step sequence notching-bite cutting. Another combined tool can be designed for the step sequence notching-notching-shearing cutting.

[0067] Furthermore, in the variant of producing the dividing result by shearing, in particular by shearing cutting, many of the accompanying features and measures can be selected similar to the variant of dividing by bite cutting. This includes, in particular, the use of one unique drive for the different working movements of the tool and / or the use of a transport gripper and / or the preferred dimensions of the notching depth, the notching angle and / or the rest of the wire during the steps of the dividing operation. BRIEF DESCRIPTION OF DRAWINGS

[0068] Further advantages and aspects of the application result from the claims and from the following description of preferred embodiments of the application, which are explained below with the aid of the drawings. Therein:

[0069] Figure 1 A side view of a wire processing machine designed as a rod forming machine is shown according to an embodiment;

[0070] Figure 2 A transport device arranged behind the dividing device for the separate further transport or handover of the divided wire rods to a further processing machine arranged behind is shown;

[0071] Figure 3 a perspective view of the assembly of the splitting device in Figure 1 ;

[0072] Figure 4 a perspective view of the assembly of the splitting device in Figure 1 ;

[0073] Figure 5 a perspective view of the assembly of the splitting device in ;

[0074] Figure 6 a perspective view of the assembly of the splitting device in ;

[0075] Figure 7 a perspective view of the assembly of the splitting device in Figure 6 ;

[0076] Figure 8 a perspective view of the assembly of the splitting device in ;

[0077] Figure 9 a perspective view of the assembly of the splitting device in Figure 8 ;

[0078] Figure 10 a perspective view of the assembly of the splitting device in Figure 9 ;

[0079] Figure 11A a perspective view of the assembly of the splitting device in ;

[0080] Figure 11B a perspective view of the assembly of the splitting device in Figure 11A ;

[0081] Figure 12 a perspective view of the assembly of the splitting device in ;

[0082] Figure 13A a perspective view of the assembly of the splitting device in 13B ;

[0083] Figure 14A a perspective view of the assembly of the splitting device in14B Figures 14C and 14D schematically show a method variant with the sequence of steps slitting - slitting - shearing, in which for all sub-steps a combined tool is used on opposite sides of the wire, which has three differently configured functional sections for the functions (i) slitting along a first direction, (ii) slitting along a second direction perpendicular to the first direction and (iii) shearing cut. DETAILED DESCRIPTION

[0084] Figure 1 A side view of a wire processing machine 100, which is designed as a rod forming machine as a whole according to an embodiment, is shown. The wire processing machine is set up for producing formed shaped parts in the form of straight wire rods. The wire processing machine has a rectangular machine coordinate system MK with a perpendicular z-axis and horizontal x- and y-axes, which are denoted by the lower case letters x, y and z. In the example shown, the x-axis extends parallel to the through direction of the wire material. Distinct from the coordinate axes of the machine coordinate system are the machine axes, which are driven in a regulated manner and are generally denoted by upper case letters (e.g. A-axis, etc.). A control unit 110 of the wire processing machine controls and coordinates the working movements of all machine axes.

[0085] The wire-shaped raw material W exists in the form of a wound material reserve (coil), which in the present example is wound on a winding machine 105. The raw material exists in the form of an electrically insulating flat material, which has an electrically conductive base material, which is wrapped by an electrically insulating insulation layer. The concept "flat material" generally denotes here a workpiece, whose electrically conductive base material has a pair of mutually parallelly oriented side faces. The base material can for example have a rectangular cross section, which has relatively sharp or slightly or completely rounded and / or bevelled edges. A flat material in the form of an insulated copper or aluminium wire with a rectangular cross section can for example be used for producing coil elements for electric motors or for producing busbars.

[0086] After leaving the winding machine 105, the flat material enters into an arrangement of subsequent structure assemblies more or less coaxially to the through axis 155. This arrangement comprises in this order along the through axis 155 of the workpiece a straightening device 120, a length measuring device 130, a stripping device 200, a brush device 160 arranged behind the stripping device, a pulling-in device 140 arranged behind the brush device and a dividing device 300 arranged behind the pulling-in device.

[0087] The straightening device 120 has two subsequently arranged straightening members with straightening rollers, which subsequently process and thereby straighten the passing workpiece along two mutually perpendicular directions.

[0088] The optional length measuring device 130 has a measuring wheel and an opposing working wheel and allows the length of the workpiece being conveyed to the subsequent unit to be measured precisely.

[0089] The integrated stripping device 200 serves to strip sections of the insulated flat material before the shaped piece is separated from the conveyed flat material. The milling device 200 comprises two subunits arranged axially offset relative to one another, namely a first subunit 200-1 arranged directly behind the length measuring device 130 and a second subunit 200-2 arranged axially spaced behind the first subunit. Each subunit is designed to strip both mutually opposing sides of the flat material simultaneously in a milling operation by means of peripheral milling. Each subunit has two milling units whose milling spindles are arranged axially parallel and axially offset to one another such that the rotational axes of the milling spindles are parallel offset relative to one another and the milling tools received in the milling spindles can be rotated about the parallel offset rotational axes. For the first subunit 200-1, the rotational axes of the two milling units are oriented vertically, i.e. parallel to the z direction of the machine coordinate system, so that the mutually opposing sides of the flat material in the horizontal plane can be stripped simultaneously. For the following second subunit 200-2, the rotational axes of the milling units are oriented horizontally, i.e. parallel to the y axis of the machine coordinate system, in order to strip the upper and lower sides of the flat material passing through vertically one above the other simultaneously. The milling units of the subunits arranged one after the other with a spacing are thus mounted offset by 90° relative to one another.

[0090] In other embodiments, the stripping device works according to other principles, for example by means of laser machining or by means of a skinning operation with a tool having a straight cutting edge which is arranged in the working position of the tool in the vicinity of the side of the base material which is to be exposed such that the portion of the insulation layer which is seized by the tool is removed from the base material when the flat material is moved relative to the tool (cf. DE 10 2017 200 745 A1).

[0091] The stripping device can also be dispensed with, for example, if the raw material to be machined is bare, i.e. not wrapped in an insulation layer. The same applies to the brush device 160 if appropriate.

[0092] The feed movement is generated by means of the draw-in device 140 arranged behind the stripping device 120, which draws the workpiece through the devices arranged in front with a draw-in profile which can be predefined by the control device and conveys it to the cutting device 300 arranged behind. Here, the feed force in the draw-in direction (x direction) is generated by the friction between the draw-in rollers or draw-in belts of the draw-in device and the flat material. As an alternative, for example, a jaw draw-in can be provided.

[0093] The cutting device 300 is arranged immediately behind the pulling-in device 140, without a bending shaping of the flat material taking place inside the wire stripping device 120, so that the cutting device separates a straight shaped piece, i.e. a wire rod, having a predefinable length from the wire-stripped flat material being conveyed. The cutting device and variants thereof will be described in detail below.

[0094] After being separated from the wire material being conveyed, the wire rod can be collected in a not shown collection device and conveyed to a further processing process, for example. In the present embodiment, a transport device 400 is arranged behind the cutting device 300, which is shown schematically in Figure 2 The transport device serves for further transporting or handing over the separated wire rod individually to a further processing machine arranged behind and also referred to herein as "rod handover device" or simply "rod handover". The transport device 400 has a horizontal linear guide 410 carried by a carriage 405, on which a transport gripper 420 is guided in a linearly movable manner. The gripping mechanism of the transport gripper is mounted on a slide 430 equipped with a servo motor, which is movable along the linear guide 410.

[0095] In Figure 2 Before the cutting operation is started, the suspended transport gripper grasps the wire rod W1 to be separated from above, holds it in a horizontal orientation during the cutting operation and transports the separated wire rod to the left for handover before the transport gripper moves back horizontally to the rear of the cutting device for grasping a new wire rod.

[0096] In the shown configuration, the transport gripper 420 is switched on in a reduced force and torque manner during the cutting operation, so that the transport gripper 420 can follow the possible length compensation movements of the wire section to be separated in a horizontally floating manner during the cutting.

[0097] The construction and function of the cutting device 300 will be explained in detail below by means of Figures 3 to 5 A perspective view of the cutting device 300 is shown in Figure 3 A perspective view of the cutting device 300 is shown in Figure 4 A vertical section of the cutting device 300 in the plane in which the notching tool and the wedge-shaped cutting edge of the cutting mechanism act, the cutting plane, is shown in Figure 5 A perspective view of the cutting device 300 is shown in

[0098] The cutting device 300 serves to separate shaped pieces having a predefined wire length from the wire material being conveyed at a cutting position, which can be predefined for the cutting. The concept "cutting position" describes a defined position along the wire, i.e. a specific point along the wire. The cutting device 300 comprises a notching mechanism 320 and a dividing mechanism in the form of a cutting mechanism 340, which can be operated in coordination with the notching mechanism, wherein in Figure 4 some components of the notching mechanism 320 are shown, and components of the cutting mechanism 340 are shown again separately in Figure 5 .

[0099] The components of the cutting device 300 are floatingly supported in their entirety along a horizontal direction parallel to the through axis 155 of the wire. To this end, the components are mounted on a base plate 310, which is guided in a linearly movable manner on a linear guide 312 in the form of a roller circulating guide. On the side facing the straightening unit 140, a servo motor 314 is mounted, which can move a pull rod, which is articulated on the base plate, in an axial manner. As a result, the cutting device 300 can be retracted in a motor-driven manner after a forward floating movement as a whole. The servo motor can also be used to actively move the cutting device during the cutting process, if the floating support is not sufficient to be able to balance the resultant force in the longitudinal direction. The servo motor can thus also be used to axially position the entire cutting device 300 along the x direction (parallel to the through axis 155).

[0100] In Figure 4The assembly of the grooving mechanism 320 can be seen in a vertical section, which is constructed such that the wire material can be grooved by shaping, that is to say without material being cut away, at the desired cutting position by means of a grooving operation from both mutually opposite sides with the grooving tools 325-1, 325-2. Here, the grooving operation is controlled such that a tapering wire cross section is left at the cutting position between the opposite notches. To this end, the grooving tools can be fed counter-parallel along a vertical first direction (parallel to the z-axis) in coordination with the axis of symmetry 155. To this end, the grooving mechanism has a servomotor-type drive 322, which drives a crankshaft 324, which is supported with a horizontal shaft, in rotation by means of a transmission 323. A first connecting rod 326-1 and a second connecting rod 326-2 are rotatably supported on the crankshaft at respective eccentric sections of the crankshaft. The first connecting rod is coupled to a first slide 327-1, which can be moved linearly upwards and downwards along the vertical first direction by means of the crankshaft through the connecting rod. On the workpiece-facing end side of the first slide 327-1 there is a receptacle for the first grooving tool 325-1, which corresponds to this and is pressed into the workpiece from above. The second connecting rod 326-2 drives a second slide 327-2, which is configured in an L shape, which can also be moved upwards and downwards parallel to the first direction and has a tool receptacle for the second grooving tool 325-2 at its front end. The two grooving tools can thus be fed by the servodrive 322 simultaneously in mutually opposite directions towards or away from the workpiece. The stroke of the connecting rods or slides is here adjusted such that the grooving tools produce notches in the workpiece without the workpiece being completely severed at the cutting position. Instead, a notch is left on each of the opposite sides, leaving a "web" of wire material with a tapering wire cross section between the notches.

[0101] The cutting mechanism 340, which functions as a dividing mechanism, is similarly configured. It comprises a cutting drive 342 in the form of a servo motor, which drives, via a transmission mechanism, a crankshaft supported with a horizontal axis, which in synchronism via two connecting rods drives a first slide 347-1, which can be moved linearly horizontally, and a second slide 347-2, which can be moved linearly parallel thereto, in mutually opposite feed directions. The slides possess on their ends tool receptacles in which a first cutting tool 345-1 with a wedge-shaped cutting edge is seated and, in opposition, a second cutting tool 345-2 with a wedge-shaped cutting edge is seated on the second slide. By means of the manipulation of the drive 342, the two wedge-shaped cutting edges can be moved towards or away from each other parallel to the second direction (y direction) symmetrically about the axis 155 in order to carry out a cutting operation. By means of the cutting tools with wedge-shaped cutting edges, the grooved wire material can be divided in the region of the tapering wire cross section at the division location by means of a bite cut, by moving the wedge-shaped cutting edges towards each other in the cutting operation relative to each other until the wire material is severed at the division location.

[0102] The active cutting edge of the grooving tool directed at the workpiece (wire) and the cutting edge of the wedge-shaped cutting edge of the cutting tool are arranged in the same plane (division plane, drawing plane in Figure 4 , which is oriented perpendicular to the through direction. The working movements of the grooving tool and the cutting tool are coordinated by means of the drive means 322, 342 assigned thereto by means of the control device 110 of the wire processing machine, so that the grooving tool can only be inserted into the workpiece when the cutting tool is returned outwardly into its retracted position, so that a collision between the grooving tool and the cutting tool is excluded. The grooving tool is then moved away from the workpiece into its retracted position before the cutting operation, in which the cutting tool severs the wire of the workpiece in the region of the tapering wire cross section by means of a bite cut.

[0103] In Figure 6 and 7 the grooving operation ( Figure 6 ) and the cutting operation ( Figure 7 ) are shown schematically. In the grooving operation ( Figure 6), using a scribing tool 325-1, 325-2 in the form of a roof-shaped scribing wedge with a sharp or slightly rounded tip region. The wedge angle KWK between the wedge faces is an obtuse angle and in the present case approximately greater than 100°, for example 120°. The scribing operation is a pure forming operation without any material removal. When the scribing tool is pressed into the wire material counter-parallel, the material is essentially expelled along the longitudinal direction of the wire without material removal. However, this material expulsion along the axial direction does not lead to a bending of the wire material, since the cutting device 300 is floatingly supported and can perform a compensating movement in the axial direction. In the region between the notches a tapered wire section WD remains, in which the wire material is strengthened relative to the undeformed wire material as a result of the scribing operation.

[0104] After the scribing tool has been retracted, the cutting tools 345-1, 345-2 are simultaneously fed in the direction of the material that has been scribed, i.e. parallel to the second direction, i.e. orthogonal to the direction of action of the scribing tool, at the opposing notches KB. Figure 7 A case is shown in which the cutting edges of the cutting tools that face each other in a plane are in such a way in contact or almost in contact with each other that the wire material is severed by a snap cut at the cutting position TP in the cutting plane. It can be seen that the snap cut takes place at the cutting position in the region of the material that has been scribed, where the wire material has been strongly strengthened by the preceding scribing operation. This leads to a very smooth and substantially defined fracture surface in the cutting operation.

[0105] In addition, the wedge faces of the scribing tool and the wedge faces of the cutting tool are responsible for producing a clearly defined chamfer in the form of an inclined, more or less trapezoidal plane on the wire end of the resulting profile piece, respectively. In some variants, the wedge angle KWS between the wedge faces of the cutting tool corresponds to the wedge angle KWK of the scribing tool, so that not only the bevel on the wide side of the flat (in the present case the bevel is constructed by the scribing tool) but also the chamfer or plane on the narrow side of the flat (in the present case the chamfer or plane is constructed by the cutting tool) are adjusted at the same angle relative to the original orientation of the side. It is also possible for the wedge angles of the cutting tool and the scribing tool to differ from each other.

[0106] Differing from the structure shown, the relative arrangement of the scribing mechanism and the cutting mechanism can also be reversed, so that, for example Figure 4 An assembly of the cutting mechanism (for vertical cutting) is shown and Figure 5 An assembly of the scribing mechanism (for horizontal scribing) is shown.

[0107] By means of Figures 8 to 10 to explain another embodiment of a wire processing machine with a two-stage splitting device (notching and snap cutting). The wire processing machine 800 is a bending machine 800 for manufacturing profiled bends, i.e. profiled shaped parts, which have one or more bends between the wire ends. In the present example case, the bending machine 800 is constructed and programmed in such a way that the bends FT in the form of wire loop elements, so-called Hairpins, which are profiled in the form of a U-bend, can be bent in order to construct an electrical motor (see Figure 10 ).

[0108] The bending machine has a machine frame with a vertical front wall 810 in which a wire guide 820 is mounted, which guides the wire to be processed along a through-axis 855. In the enclosed area behind the machine front wall 810 there are, inter alia, a straightening unit and a pulling-in device with which the wire is drawn out of a continuous stock and, after straightening, is pushed forward through the wire guide 820. The wire guide and the devices arranged in front of it, which are coupled to it in a torsion-proof manner (pulling-in device and straightening unit), can be rotated around the through-axis 855 in a controlled manner. The components of the splitting device 900 are arranged in a vertical plane behind the wire guide. On the exit side of the splitting device, which faces away from the machine wall, there is a bending unit 850, which is not shown in detail here, with one or more bending tools for producing prescribed bends in the wire material. During the manufacturing process, the wire material is fed forward in the direction of the bending unit 850 and is bent there one or more times in one or more mutually offset bending planes in order to obtain the desired bending geometry of the shaped part. The manufactured shaped part is then separated from the wire stock being fed by means of the splitting device 900.

[0109] The splitting device 900 is supported as a whole floating in parallel to the x-direction of the machine coordinate system or in parallel to the through-axis 855 in order to allow a compensatory movement of the length extension on the manufactured shaped part during the notching and cutting operation, if necessary. A servo motor, which can be used to move the splitting device 900 actively in parallel to the through-axis 855 during the splitting process, can also be connected if the floating support is not sufficient to be able to compensate the resultant force in the longitudinal direction (similar to the servo motor 314 of Figure 2 ).

[0110] The slitting device 900 comprises a grooving mechanism 920 and a cutting mechanism 940, which together form a cross-shaped arrangement with four sub-units. The grooving mechanism 920 comprises a first slide 927-1 supported in a linearly movable manner, which can be moved back and forth radially to the material passage axis 855 in a first direction by means of a flange-connected servo drive via an intermediate connected drive mechanism with ball screw drive. On the tool-facing end of the slide there is a tool receptacle for receiving a first grooving tool 925-1. Opposite in radial direction a second slide 927-2 is mounted, which can feed a second grooving tool 925-2 counter-parallel to the first grooving tool in the direction of the workpiece or in the opposite direction (parallel to the first direction) by means of its own servo drive. The first direction is inclined by 45° with respect to the y and z directions in the y-z plane perpendicular to the passage axis.

[0111] The two sub-units of the cutting mechanism 940 are arranged with a peripheral offset of 90° with respect to the respective unit of the grooving mechanism. Here, the first slide 947-1 of the cutting mechanism carries a first cutting tool 945-1 with a wedge-shaped cutting edge, and opposite the second slide 947-2 carries the second cutting tool 945-2 with a wedge-shaped cutting edge. In Figure 10 The arrangement of the tools can be seen particularly clearly in

[0112] The slides are each mounted on a plate-like support, which can be moved not only parallel to the z direction but also parallel to the y direction, so that the tools carried by the slides and the working direction of the tools can be coordinated with the respective workpiece geometry.

[0113] In this embodiment, one own servo drive is provided for each tool, each of the two grooving tools and each of the two cutting tools. The servo drives are coordinated by the control unit of the wire processing machine in such a way that in the same plane (slitting plane) at the location of the slitting position of the wire first the grooving tools are fed counter-parallel in order to produce opposite notches, thereafter the grooving tools are pulled back radially, and thereafter the cutting tools with wedge-shaped cutting edges are fed radially inwards along a second direction perpendicular to the first direction until the wire material is cut off in the region of the tapering wire tab by means of a bite cut.

[0114] In contrast to the illustration in Figure 8 there are also embodiments in which the components of the slitting device and the components of the bending unit for producing the bend are in a common plane. The slides and tools of the bending unit can for example be arranged respectively along the circumferential directionFigure 9 The units of the slotting mechanism 920 and the cutting mechanism 940, which are inclined at an angle of 45° with respect to the horizontal, are arranged between them. They are able to form a cross-shaped arrangement with units that are oriented horizontally and vertically.

[0115] It has been shown in numerous tests that a two-stage slitting operation carried out in the production of shaped formed parts by means of shaping and subsequently cutting off in the gradually tapering wire section by means of a bite cut, together with a preceding slotting, leads to wire ends that are very well defined in terms of geometry. Comparative tests were carried out for the purpose of illustration, in which the cutting off was carried out in a two-stage method according to the application on the one hand and, for comparison, a one-off bite cut operation was carried out without prior slotting on the other hand.

[0116] For the purpose of explanation, Figure 11A Views of the wire end of a flat wire with a rectangular cross section are shown, on the one hand from the wide side (upper part) and on the other hand from the narrow side (lower part). The results of a finite element (FEM) simulation are shown on the left, photographic images of the wire end according to the experiment are shown on the right, mirror-inverted thereto. A large number of tests were carried out. Due to the good agreement between simulation and experiment, the results are considered to be representative and important.

[0117] In the bite cut operation without prior slotting ( Figure 11A ), when a slot is produced on the opposing wide side of the material, a clear cross-sectional widening in the form of an outwardly pointing bulge WB of the material is produced on the narrow side. In this region, the material is pushed outward beyond the envelope contour of the original unprocessed wire material by material displacement. In addition to this, the resulting geometry corresponds to the desired geometry, which has a substantially flat, bevelled chamfer on the wide side of the wire end.

[0118] In contrast, Figure 11B The results when carrying out the cutting operation together with the prior slotting operation are shown. As can be seen from the two lower part diagrams, a clear cross-sectional tapering in the form of a slightly inwardly curved, otherwise more or less flat chamfer FS is also produced on the narrow side of the wire material. The wire end produced in this way is thus provided with an inwardly pointing chamfer FS not only on the wide side but also on the narrow side, so that no material projects beyond the envelope contour of the original material in the end region.

[0119] The drive solutions of the embodiments shown above are merely exemplary. There are also other possible solutions for manipulating the slotting tool and the cutting tool.

[0120] Schematic Figure 12The components of the drive concept are shown exemplarily, which with a unique drive for the notching tool and the cutting tool can suffice. The drive, which is not shown, drives a cam disk 1210, which by means of the drive can be rotated about a rotational axis running parallel or coaxially to the through axis 155. The cam disk is equipped with a cam track, which in the present case is introduced in the form of a circumferential groove 1212 or can also be on the outer or inner side of the cam disk. The course of the cam track is taken up by rollers 1214, which in the present case are arranged on vertically movable first slides 1227-1, 1227-2 and horizontally movable second slides 1047-1, 1047-2. Analogous to the first embodiment, the slides guided in a manner linearly movable radially to the through axis 155 have a tool receptacle for the notching tool or the cutting tool on their inner side facing the workpiece.

[0121] The resetting of the slide movement can take place either forcibly by the geometry of the groove 1212 or by the resetting force of a spring, which presses the rollers or elements coupled with the rollers onto the cam track, depending on the construction form. In this concept, not only the vertical notching movement but also the horizontal cutting movement are controlled with a unique cam disk 1210. The cam disk can be exchanged in order to realize other movement characteristics. Very high forces can be generated by the cam geometry, which are advantageous for the forming process, firstly in notching but also in the case of the clamping cut. In the present case, the cam disk is not revolved without limit but reversibly moved in a range of a maximum of 90° (see double arrow). The adjustment of the notch depth takes place by the angle of rotation of the cam disk. The greater the extent of the maximum range of revolution of 90° is used, the deeper the notch is punched, respectively. The concept of the cam disk is a compact solution, in which both movements (for the notching tool and the cutting tool) can be realized on a small space. A good and variable force transmission ratio is generated when using cams with different slopes.

[0122] The following embodiment is also possible, in which only two servo drives with wedge-shaped tools are provided, which are used not only for notching but also for cutting. For this purpose, the wire can be rotated by 90° between notching and cutting, for example.

[0123] The wedge-shaped tools can also be constructed or designed in such a way that by corresponding movements in the z and y direction on the wire W not only a notching operation can be carried out but also in the same plane a cutting operation can be carried out in a direction perpendicular thereto. Figure 13ATo this end a notching operation is shown with two tools 1330-1, 1330-2 which are triangular on the free end and have two wedge-shaped cutting edges which extend at 90° to each other. On the two flat sides of the wire which are rectangular in cross-section and which lie opposite each other in the y direction, kerfs are glazed. Figure 13B A cutting operation is shown with the same tools which are triangular on the free end, wherein now wedge-shaped cutting edges which extend at 90° offset are used. The feed direction for the cutting operation extends parallel to the z direction. The tools thus function not only as notching tools but also as cutting tools. They have wedge-shaped cutting edges for each operation, wherein the cutting edges extend perpendicularly to each other.

[0124] The slitting device of the present embodiment has a notching mechanism and a cutting mechanism which can be operated after the notching mechanism in time, which share the same components, so that the notching mechanism is also used as a cutting mechanism. The notching mechanism and the cutting mechanism are thus not necessarily separate devices from each other, they can be integrated.

[0125] The tools 1330-1, 1330-2 in Fig. 13 are examples of a combined tool which has an integrated notching tool and an integrated snap-off cutting tool which have cutting edges which extend orthogonal to each other. In Figure 13A the notching tool is inserted synchronously with the workpiece, in Figure 13B the cutting tool is carried out with symmetrical wedge-shaped cutting edges.

[0126] By means of Figures 14A to 14D Another process variant is described in which other combined tools 1430-1, 1430-2 are used. In the combined tools an first notching tool 1425-1 and a second notching tool 1425-2 with wedges which are orthogonal to each other are integrated as well as a cutting tool 1435-1 which is designed as a scissors.

[0127] In the process a workpiece W in the form of a wire with a rectangular cross-section is divided or slitted at a slitting position. To this end the wire W is first notched simultaneously on the flat sides which lie opposite each other in the y direction (notching operation 1). Figure 14A Thereafter the wire is notched on the flat sides which lie opposite each other in the z direction at the same axial position with the same combined tools 1430-1, 1430-2 (notching operation 2). Figure 14B The workpiece is thus notched on all four sides in a two-stage notching operation (or by means of two notching operations) so that there are V-shaped kerfs there. The kerf bottoms KG which are shown in dashed lines in Figure 14C limit the tapering wire cross-section at the slitting position.

[0128] After full grooving, the wire is completely severed at the cutting point during the shearing operation. For this purpose, cutting tools 1435-1 and 1435-2, respectively, constructed for shearing, are integrated into the combination tools 1430-1 and 1430-2. One cutting tool, for example, cutting tool 1435-1, serves as the upper blade of the cutting mechanism, and the other cutting tool, for example, cutting tool 1435-2, serves as the lower blade of the cutting mechanism. The cutting tools 1435-1 and 1435-2 can also be referred to as shearing tools or scissors.

[0129] exist Figure 14D The construction of the cutting tools (shear cutting tools) can be clearly seen in the side view. Each cutting tool 1435-1, 1435-2 has cutting edges 1436-1, 1436-2 that extend linearly parallel to the y-direction when the tool is fixed to the tool holder of its respective machine shaft and properly adjusted. The cutting edges are constructed on an asymmetrical cutting wedge, the limiting interfaces (free surfaces) 1437-1, 1437-2 of which are located near the cutting position are oriented almost parallel to the zy-plane, while another limiting interface (pressure surface) 1438-1, 1438-2 forms a wedge angle KW of less than 90° with the aforementioned limiting interfaces 1437-1, 1437-2 at the cutting edges 1436-1, 1436-1 and thus extends obliquely with respect to the y and z directions. The wedge angle KW is approximately half the size of the wedge angle KWK of the grooving tool that has undergone the preceding grooving step.

[0130] To perform the cutting operation, the wire W remains stationary, i.e., is not pushed forward. The combination tool moves by means of the assigned machine axis such that the cutting edges 1436-1, 1436-2 are substantially in the cutting position and cutting plane of the stationary wire.

[0131] Therefore, starting from the last grooving operation, two cutting tools need axial movements parallel to the z-axis and opposing movements parallel to the x-direction. A narrow cutting kerf exists between the free surfaces of the cutting wedges at the dicing position TP, with dimensions typically within a range of one-hundredth or a few-hundredths of a millimeter.

[0132] In Figure 14DThe relative positions shown in the middle serve as a starting point for the shearing cutting tool which is then fed in opposite directions parallel to the z direction (arrows). Here, the cutting edges 1436-1, 1436-2 first come into contact more or less simultaneously (in the ideal case simultaneously) with the bottom of the facing notches and are then pushed further into the interior of the wire material. On further penetration of the cutting wedge, the wedge faces 1436-1, 1436-2 act as pressure surfaces which push the material out of the shear location in opposite directions. In the cutting phase, the cutting edges 1436-1, 1436-2 approach each other symmetrically with respect to the wire longitudinal axis (wire center) MA until the wire cross section in the middle is very thin and the material breaks in the breaking phase on exceeding the maximum shear stress. If the wire is cut before the cutting edges hit each other, the opposite feed can be stopped. This can be the case, for example, for rather hard or brittle materials, like for example spring steel. It is also possible that the cutting edges pass each other by at the end of the shearing cutting operation. This is often the case when shearing cutting copper or other relatively soft metals.

[0133] By means of the shearing cutting operation, it is possible, with correct setting of the process parameters, to produce end faces on the separated wire ends which are macroscopically flat and oriented perpendicular to the wire longitudinal axis. The end sections of the wire then have the shape of a rectangular prism with a flat end face and are particularly suitable for large-area contact, for example by means of a welding process.

[0134] The complete chipless shear cut of the example in Fig. 14 thus consists of three steps which can be described as follows.

[0135] First step: two wedge-shaped knives arranged at right angles with respect to the wire at a distance from each other are moved symmetrically towards the wire center. This movement is stopped after a defined feed of the tool and thereby "only" material is displaced and no cutting / shearing operation takes place. After this step, the material is notched on both sides.

[0136] Second step: two further wedge-shaped knives arranged at right angles with respect to the wire at a distance from each other (but orthogonally with respect to the other two wedge-shaped knives) are likewise moved symmetrically towards the wire center. This movement is likewise stopped after a defined feed of the tool and thereby "only" material is displaced and no cutting / shearing operation takes place. After this step, the material is notched on four sides.

[0137] Third step: two scissors knives arranged at right angles with respect to the wire at a distance from each other are moved symmetrically towards the wire center. The cutting edges of the two knives are moved towards the wire center until the wire is sheared off.

[0138] The three steps for the four-sided grooving and subsequent slitting by means of shearing cutting should be carried out in one plane. For rectangular material, the wire end after cutting has the shape of a truncated pyramid.

[0139] The process of the type described here can be used, for example, for the geometric shaping of wire ends in copper components, such as hairpins, busbars, contact pins, etc. Thus, grooving and cutting of chain links is also possible.

Claims

1. Method for manufacturing shaped parts from wire, wherein: a wire (W) is drawn from a wire store and fed to a wire processing machine (100, 800), the wire is straightened in the wire processing machine (100, 800) and a shaped part having a predefinable wire length is separated from the straightened wire, wherein for separating the shaped part from the fed wire, firstly in at least one notching operation the wire (W) is notched from both mutually opposite sides at a cutting position (TP) provided for the separation by means of notching tools (325-1, 325-2, 925-1, 925-2, 1330-1, 1330-2, 1425-1, 1425-2) in such a way that between the mutually opposite notches (KB) at the cutting position a tapering wire cross section remains; and subsequently in a splitting operation the notched wire is cut at the cutting position (TP) in the region of the tapering wire cross section by means of two splitting tools (345-1, 345-2, 945-1, 945-2, 1330-1, 1330-2, 1435-1, 1435-2) acting on the opposite sides of the wire and fed synchronously in mutually opposite feed directions perpendicular to the wire axis until the wire is severed at the cutting position (TP), wherein the splitting operation is a cutting operation, wherein for the severing operation the notching tools (325-1, 325-2, 925-1, 925-2, 1330-1, 1330-2, 1425-1, 1425-2) are moved away from the wire before the splitting tools (345-1, 345-2, 945-1, 945-2, 1330-1, 1330-2, 1435-1, 1435-2) sever the wire.

2. The method of claim 1, wherein, The notching operation is carried out as a shaping operation, wherein the notches are produced exclusively by material shaping without material being cut away.

3. The method according to claim 1 or 2, characterized in that, The feed movement of the notching tools (325-1, 325-2, 925-1, 925-2, 1330-1, 1330-2, 1425-1, 1425-2) is controlled in such a way that the notching tools (325-1, 325-2, 925-1, 925-2, 1330-1, 1330-2, 1425-1, 1425-2) are fed synchronously in mutually opposite feed directions perpendicular to the wire axis and / or the extrusion depth of the notching tools is at least 10% of the extent of the wire not notched in the first direction and / or in the region of the tapering wire cross section there is a remaining width perpendicular to the wire longitudinal direction which is at or less than 90% of the original diameter in the first direction.

4. The method of claim 3, wherein, The extrusion depth of the notching tools is in the range of 20% to 50% of the extent of the wire not notched in the first direction. The extrusion depth of the notching tools is in the range of 20% to 50% of the extent of the wire not notched in the first direction.

5. The method of claim 3, wherein, The remaining width is in the range of 50% to 80% of the original diameter along the first direction.

6. The method of claim 1 or 2, wherein, The wire (W) is split at the split location (TP) by a bite cut or a shear cut after the grooving operation.

7. The method of claim 6, wherein, The wire is split at the split location (TP) by a bite cut in a cutting operation by moving the wire between two split tools with wedge-shaped cutting edges, which are formed as cutting tools (345-1, 345-2, 945-1, 945-2, 1330-1, 1330-2), and moving the wedge-shaped cutting edges towards each other relative to each other until the wire is severed at the split location (TP), wherein the cutting edges formed at the wedge-shaped cutting edges are in a common plane.

8. The method of claim 7, wherein, The grooving tools (325-1, 325-2, 925-1, 925-2, 1330-1, 1330-2) are opposite each other along a first direction and are fed parallel to the first direction, the cutting tools with wedge-shaped cutting edges are opposite each other along a second direction and are fed parallel to the second direction, and the first and second directions extend perpendicularly to each other.

9. The method of claim 1 or 2, wherein, The splitting operation is designed as a shear operation, wherein the wire is split at the split location (TP) by a shear cut by holding the wire between two split tools formed as shear cutting tools (1435-1, 1435-2), which act on different axial sides of the split location (TP) and are moved synchronously in mutually opposite feed directions perpendicular to the wire axis until the wire is severed at the split location (TP).

10. The method of claim 9, wherein, The shear operation is designed as a shear cut operation, wherein the wire is split at the split location (TP) by a shear cut by holding the wire between a shear cutting tool formed as an upper blade and a shear cutting tool formed as a lower blade and moving the cutting edges of the shear cutting tools towards each other in axially offset planes opposite each other until the wire is severed at the split location (TP).

11. The method of claim 10, wherein, The cutting edges of the shear cutting tools are moved towards each other in axially offset planes opposite each other and also beside each other until the wire is severed at the split location (TP).

12. The method of claim 9, wherein, In a grooving operation before the shear operation, the wire is first grooved on two sides opposite along a first direction and thereafter on two sides opposite along a second direction, wherein the first and second directions extend perpendicularly to each other.

13. The method of claim 1 or 2, wherein, There is no movement of the wire along the wire longitudinal direction between the grooving operation and the splitting operation, so that the grooving operation and the splitting operation are carried out in the same plane (TE). There is no movement of the wire along the wire longitudinal direction between the grooving operation and the splitting operation, so that the grooving operation and the splitting operation are carried out in the same plane (TE).

14. The method of claim 1 or 2, wherein, For the notching operation and for the dividing operation each one combined tool (1330-1, 1330-2, 1430-1, 1430-2) is used on opposite sides of the wire (W), which has at least one integrated notching tool and one integrated dividing tool, wherein the combined tools are fed in pairs in time succession synchronously along two mutually perpendicular directions.

15. The method of claim 1 or 2, wherein, The wire sections to be separated are grasped before the notching operation and / or the dividing operation by means of a transport gripper (420) and the separated shaped pieces are transported after the end of the dividing operation by means of the transport gripper to a work station arranged behind.

16. The method of claim 15, wherein, The transport gripper (420) is guided in a manner that it can be moved linearly parallel to the wire transport axis and is activated in a force- and torque-reducing manner during the notching operation and / or during the dividing operation, so that it can follow the length-compensating movement of the wire sections to be separated floatingly during the notching operation and / or during the dividing operation.

17. The method of claim 1 or 2, wherein, A wire (W) having a rectangular cross section is processed.

18. The method of claim 17, wherein, A wire (W) having a rectangular cross section in the form of a flat material having two mutually parallel wide sides and two narrow sides oriented perpendicular to the wide sides is processed.

19. The method of claim 1 or 2, wherein, After straightening, straight wires having a predefined length are separated from the straightened wire, or after straightening and before cutting, one or more bends are produced in the straightened wire, so that the shaped pieces are curved pieces.

20. Wire processing machine (100, 800) for producing shaped pieces from a wire (W), comprising: a pulling-in device for pulling in a wire from a wire store; a straightening unit for straightening the wire; and a cutting device (300, 900) for separating shaped pieces from the wire at a cutting position (TP) provided for the separation, wherein the cutting device (300, 900) has a notching mechanism (320, 920) and a dividing mechanism (340, 940) which can be operated in time after the notching mechanism, wherein the notching mechanism (320, 920) is configured for notching the wire in at least one notching operation from two mutually opposite sides at the cutting position (TP) provided for the separation by means of notching tools (325-1, 325-2, 925-1, 925-2, 1330-1, 1330-2, 1425-1, 1425-2) in such a way that a tapering wire cross section remains at the cutting position between the opposite notches, and The dividing mechanism (340, 940) has two dividing tools (345-1, 345-2, 945-1, 945-2, 1330-1, 1330-2, 1435-1, 1435-2) in the adjusted state, wherein the wire (W) can pass through between the two dividing tools, wherein the dividing tools can be fed synchronously in mutually opposite directions perpendicular to the wire axis for carrying out a dividing operation, wherein the dividing tools are configured such that, in the region of the tapering wire cross-section, the notched wire is cut at the cut location (TP) by the dividing tools (345-1, 345-2, 945-1, 945-2, 1330-1, 1330-2, 1435-1, 1435-2) being fed synchronously in mutually opposite directions perpendicular to the wire axis during the dividing operation until the wire is severed at the cut location (TP), wherein the dividing mechanism (340, 940) is configured as a cutting mechanism and the dividing tools (345-1, 345-2, 945-1, 945-2, 1330-1, 1330-2, 1435-1, 1435-2) are designed as cutting tools, wherein, for carrying out a severing operation, the notching tool (325-1, 325-2, 925-1, 925-2, 1330-1, 1330-2, 1425-1, 1425-2) is moved away from the wire before the dividing tools (345-1, 345-2, 945-1, 945-2, 1330-1, 1330-2, 1435-1, 1435-2) sever the wire.

21. The wire processing machine of claim 20, wherein, The notching tool (325-1, 325-2, 925-1, 925-2, 1330-1, 1330-2, 1425-1, 1425-2) is configured as a forming tool such that the notching can be produced exclusively by material forming without material removal and / or the notching mechanism is configured to control the feed movement of the notching tool (325-1, 325-2, 925-1, 925-2, 1330-1, 1330-2, 1425-1, 1425-2) such that the notching tool (325-1, 325-2, 925-1, 925-2, 1330-1, 1330-2, 1425-1, 1425-2) is fed synchronously in mutually opposite feed directions perpendicular to the wire axis.

22. The wire processing machine of claim 20 or 21, wherein, The cutting mechanism is designed in the form of a nip cutting mechanism which has two cutting tools (345-1, 345-2, 945-1, 945-2, 1330-1, 1330-2) with wedge-shaped cutting edges in the adjusted state, the wire (W) being able to pass through between the two cutting tools, wherein the wedge-shaped cutting edges can be moved towards one another relative to one another for carrying out a cutting operation, wherein the cutting mechanism is configured such that, in the region of the tapering wire cross-section, the notched wire is cut at the cut location (TP) by the wedge-shaped cutting edges being moved towards one another until the wire is severed at the cut location (TP), The slotted wire is slit at the splitting position (TP) in the region of the tapering wire cross-section by a bite cut, by moving the wedge-shaped cutting edges of the cutting tools (345-1, 345-2, 945-1, 945-2, 1330-1, 1330-2) relative to one another towards one another in the cutting operation in a common plane until the wire is severed at the splitting position (TP).

23. The wire processing machine of claim 20 or 21, wherein, The slitting tools (325-1, 325-2, 925-1, 925-2) are arranged opposite one another along a first direction and are able to be fed parallel to the first direction, the cutting tools (345-1, 345-2, 945-1, 945-2) having wedge-shaped cutting edges are arranged opposite one another along a second direction and are able to be fed parallel to the second direction, and the first and second directions run perpendicularly to one another.

24. The wire processing machine of claim 20 or 21, wherein, The splitting mechanism is designed as a shearing mechanism which is configured such that the wire is slit at the splitting position (TP) by shearing, by holding the wire between two splitting tools which are constituted as shearing tools (1435-1, 1435-2) which act on different axial sides of the splitting position (TP) and are able to be moved synchronously in mutually opposite feed directions perpendicular to the wire axis, until the wire is severed at the splitting position (TP).

25. The wire processing machine of claim 24, wherein, The slitting mechanism is configured such that the wire is slotted first on two sides opposite along a first direction and thereafter on two sides opposite along a second direction in a slitting operation prior to a shearing operation, wherein the first and second directions run perpendicularly to one another.

26. The wire processing machine of claim 20 or 21, wherein, The splitting device has a combined tool (1330-2, 1330-2, 1430-1, 1430-2) on the opposite sides of the wire respectively, the combined tool having at least one integrated slitting tool and one integrated splitting tool, wherein the machine axis of the wire processing machine is configured such that the combined tools are able to be fed synchronously in pairs in two directions perpendicular to one another in time succession.

27. The wire processing machine of claim 20 or 21, wherein, The slitting tools (325-1, 325-2, 925-1, 925-2, 1330-1, 1330-2, 1425-1, 1425-2) are constituted as roof-shaped slitting wedges having a sharp or rounded tip region.

28. The wire processing machine of claim 27 wherein, The wedge angle (KWK) enclosed by the wedge surface is in the range from 90° to 140° and / or the wedge-shaped cutting edges of the cutting tools (345-1, 345-2, 945-1, 945-2) have a wedge angle (KWS) in the range from 90° to 140°.

29. The machine of claim 20 or 21, wherein, The cutting edges of the notching tools (325-1, 325-2, 925-1, 925-2, 1330-1, 1330-2, 1425-1, 1425-2) of the notching mechanism and the cutting tools (345-1, 345-2, 945-1, 945-2, 1330-1, 1330-2, 1435-1, 1435-2) of the cutting mechanism are arranged in a common plane.

30. The machine of claim 20 or 21 wherein, The notching mechanism (320, 820) has a unique drive (322) and / or the cutting mechanism (340, 840) has a unique drive (342).

31. The machine of claim 30 wherein, The drive (322) of the notching mechanism (320, 820) is coupled to both notching tools (325-1, 325-2) for synchronous feed.

32. The machine of claim 30 wherein, The drive (342) of the cutting mechanism (340, 840) is coupled to both cutting tools (345-1, 345-2) for synchronous feed.

33. The machine of claim 20 or 21 wherein, The cutting mechanism (300, 900) is supported floating parallel to the passage direction of the wire (W) or can be actively moved parallel to the passage direction of the wire (W) by means of a drive.

34. The machine of claim 20 or 21 wherein, The wire processing machine further comprises a transport gripper (420) for grasping the wire section to be separated before the notching operation and / or the cutting operation and for transporting the separated wire section to a station arranged behind after the cutting operation.

35. The machine of claim 34 wherein, The transport gripper (420) is guided linearly movable parallel to the wire transport axis and can be switched on with reduced force and torque during the notching operation and / or during the cutting operation, so that the transport gripper can follow the length compensation movement of the wire section to be separated floating during the notching operation and / or during the cutting operation.

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