METHOD FOR THE MULTI-CORE DEBURRING OF WIRES AND ASSOCIATE

Abstract

The invention relates to a method for the multi-core deburring of wires, preferably wires (1) separated from a wire strip comprising a plurality of wire strips which are arranged parallel to each other, in particular for producing round wires and shaped wires. The wires (1) are, after passing through a pair of separating rollers (3), separated by a separating roller unit (4) according to even-numbered and odd-numbered wires, such that two stands of mutually distanced wires (1) are formed. Both of the wire strands (1) then traverse according to an adjustable tensile stress, respectively a deburring station provided with deburring blades. The tensile stress is selected in such a manner that after taking into account the notch angle and the blade angle of the deburring blades, the wires (1) undergo an automatic, central alignment ensuring chips are removed in a uniform manner on both sides of said wires (1). Subsequently, the wires (1) are brought together in a traction unit (6) comprising rollers to again form a common strand of wires (1). The invention also relates to a corresponding device.

Description

The invention relates to a method for simultaneously deburring a multiplicity wire conductors, preferably a plurality of wire conductors that are separated from a wire conductor ribbon and are parallel to each other, in particular for producing round and shaped wires, wherein a sheet metal ribbon is first pregrooved on one or both opposite faces so as to create the wire conductors of the wire conductor ribbon, after which grooving the wire conductors still connected by webs undergo a flexing process so as to then transform the webs into thin frangible webs that are easily separable from each other and form smooth and nearly burr-free edges when detached, each web undergoing repeated bending deformation about its longitudinal axis in such a way that incipient cracks forming the frangible web are created by fatigue failure at the webs, wherein the frangible web can also be opened locally. Production of this type of wire conductor ribbon is described in WO 2008/135002 [US 2010/0129678].

In the conventional production of round wire, a wire conductor is essentially cast, extruded or hot-rolled, and subsequently stripped, scraped, pickled, etc., after which this wire conductor is then drawn until reaching the desired final size.

Based on the above description, individual wire conductors, for example of very small size such as less than 1 mm in diameter, can be extracted from a wire conductor ribbon for further processing in a conventional wire production process. The entire preproduction process is then effected by rolling, which generally is more cost-effective; however, it is also possible when producing fine and ultrafine wire, for example for a plurality of wire conductors to be extracted simultaneously from the wire conductor ribbon produced from a metal sheet, where what is left is only a running-out starting-material ring that has been produced in preproduction exclusively by rolling. To ensure quality, it is advantageous for the edges together with frangible webs and frangible web remnants to be extracted from the wire conductors.

The object of this invention is therefore to provide a method for deburring wire conductors that have been created by the process of separating a wire conductor ribbon formed out of a metal sheet. This object is achieved according to the invention by an approach in which the wire conductors, after passing through a separating roller pair, are spread apart according to even-numbered and odd-numbered wire conductors by a spreading roller unit such that two arrays of mutually spaced wire conductors are created, wherein furthermore the two arrays of wire conductors pass under adjustable draw tension through respective deburring stations provided with respective deburring cutters, where the draw tension is selected such that an automatic central alignment, and thus a two-sided uniform removal of chips, is effected on the wire conductors due to the action of the groove-flank angle and of the adjusted angle of the deburring cutters, and wherein finally the wire conductors are reunited into a common group of wire conductors by rollers of a drawing unit, thereby achieving uniform drawing conditions for all wire conductors and transferring the wires on for further processing.

The advantage achieved by the invention essentially consists in the fact that, due to the separation of the initially closely adjacent wire conductors into two arrays, a space of the width of one wire conductor is now created between the wire conductors, thereby allowing deburring to be effected laterally on the originally present frangible webs. The subsequent reuniting of the two arrays in the drawing unit enables the then deburred wire conductors to be transferred on for further processing. If another means is found to ensure that the same draw force is applied to both arrays—by means of appropriately controlled electric motors, for example—then the subsequent reuniting of the two arrays can be eliminated. In other words, both arrays can also be moved along for separate further processing in the event this is desirable in terms of the process. If the selected spacing between the spreading rollers and the drawing unit is sufficiently large and the deburring station is then positioned centrally between these, the individual wire conductors will automatically align themselves centrally relative to the deburring cutters of the deburring device, since the cutting widths of the chips on both sides of the wire conductors will automatically adjust to be of equal width due to the pitches of the grooves (for which a groove-flank angle ranging between 45 and 90′ is advantageous). This obviates the need for horizontally guiding the wire conductors upstream of the deburring devices. The cutting pressure is sufficient to appropriately set the wire conductors centrally. As a result, the surfaces of the separating surfaces are completely removed reliably bilaterally on both sides of the respective wire conductors—a factor which is necessary to ensure quality.

In a preferred embodiment of the invention, the wire conductors pass in the deburring station through a comb-like deburring device provided with tines that form deburring cutters.

It is furthermore critical that the wire conductors in the deburring station be transported under tension, where the drawing unit provided with guide grooves generates the draw force that is also required to advance the wire conductors, while the separating roller pair as well as the spreading roller unit provided with guide grooves generate a braking force.

Appropriately coordinating these units with each other enables the specific advantageous tension to be effected. It can also be advantageous in this regard if the tension in the wire conductors can be controlled in a continuously variable fashion between the two units.

It has furthermore been found advantageous within the scope of the invention for the wire conductors not to be subject to any horizontally restricted guidance so as to provide a uniform, two-sided deburring operation in the region upstream and downstream of the deburring station. This enables the wire conductors to be horizontally aligned centrally by the two cutters engaging on the left and the right so as to achieve a uniform two-sided deburring. The effect of self-alignment by the wire conductors in the deburring device is most efficient if the width-to-thickness ratio is not significantly greater than 1:1. Another aspect of the invention is that the wire conductors are guided upstream of the deburring devices only under light contact pressure across respective guide rollers; that is, this pressure is applied only very gently. This attenuates vibration and furthermore ensures that the wire conductors get twisted before passing through the deburring device, while the possibility of a horizontally centered alignment still exists.

The feeding of a new wire conductor ribbon into the deburring station is laborious in that the start of the wire conductor ribbon into the upstream separating rollers is not separated, and the wire conductor ribbon is guided and threaded up to the drawing unit when the spreading roller have not been mounted. During subsequent configuration, the separating rollers are activated and the wire conductor ribbon is separated until the separated wire conductors have reached the drawing unit. Then a sufficient length of wire conductor is generated between the separating rollers and the drawing unit to allow the spreading rollers to be mounted. At the same time, the array of wire conductors is divided up so that, for example every second wire conductor number is guided over the top spreading roller, while the other wire conductors pass over the bottom spreading roller and are fitted there into the respective guide grooves. The wire conductors are then placed under tension and the deburring devices are installed. In order to allow this to be done as rarely as possible, it is useful to employ long wire conductor ribbons, although the length of these cannot be unlimited. For this reason, the invention proposes an approach whereby the wire conductor ribbon passes through a welding station before entering the separating roller pair, in which station a new wire conductor ribbon is butt-welded on when the end of a wire conductor ribbon is reached such that the individual wire conductors are flush to one another. This approach essentially allows the process in principle to be carried out with an “endless” wire conductor ribbon, as long at least as wire conductor ribbons of identical dimensions and geometry are being worked. Specifically, it has been found that the welded seam does not negatively affect the separation of the individual wire conductors from each other at the frangible web, and this is particularly true according to another proposal of the invention whereby the welding bead formed on the welding seam is ground flat on both sides of the wire conductor ribbon, and the welding bead at the grooves is also almost completely removed by an appropriately shaped tool by simultaneously grinding the top and bottom face of the wire ribbon.

In terms of an apparatus, the object of the invention is achieved by a deburring station for a wire conductor ribbon that is formed from a metal sheet pregrooved on one or both faces and in which wire conductors still connected by webs after grooving undergo a flexing process so as to transform the webs into thin frangible webs that are easily separable from each other, and form smooth and nearly burr-free edges when detached, whereby, after undergoing repeated bending deformation about their longitudinal axis, incipient cracks forming the frangible webs are created by fatigue failure at the webs, wherein the frangible web can also be opened locally, and the deburring station includes a separating roller pair that separates the wire conductor ribbon into wire conductors, the object of the invention furthermore being achieved by a spreading roller unit in which even-numbered wire conductors are spread apart relative to uneven-numbered wire conductors such that two arrays of mutually spaced wire conductors are created, furthermore one deburring device for each of the two arrays of wire conductors, as well as rollers forming a drawing unit in which the wire conductors are reunited into a common group.

The deburring device here advantageously includes tines arranged as in a comb and forming deburring cutters.

Another advantageous aspect is that the deburring device is oriented at an acute angle to the travel direction of the wire conductors so as to reinforce the self-alignment effect of the wire conductors since the cutting width is increased, and also to ensure is downward ejection of chips.

Regardless of the angle between the wire conductors and the deburring device that is specifically selected or set in terms of the operation, what has been found advantageous for this purpose is a value of approximately 45.

Provision is furthermore made within the scope of the invention whereby the deburring device is adjustable longitudinally of the tines. This allows the deburring device to be reset if the cutters have become dull in the working area.

In order finally to be able to feed the separated wire conductors to the deburring device in an ordered arrangement and alignment, it can be advantageous for the rollers of the spreading unit to be provided with guide grooves for the wire conductors. The deburring device should be placed centrally between the spreading rollers and the drawing unit; the selected spacing here from the spreading rollers to the drawing unit must be sufficiently great to allow the wire conductors to be easily aligned automatically in the horizontal plane according to the cutting pressure.

The following describes the invention in more detail with reference top an embodiment illustrated in the drawing in which:

FIG. 1 is a schematic side view of an apparatus for carrying out the method according to the invention;

FIG. 2 is a view of the deburring device in the direction of production;

FIG. 3 is a side view of the structure shown in FIG. 2;

FIG. 4 is a detail in cross-section from FIG. 2.

The arrangement shown in FIG. 1 deburrs wire conductors 1 that have been separated out from a wire-conductor ribbon 2 comprising a plurality of parallel wire conductors. This deburring method is intended in particular for producing round and/or profiled wires.

In order to form the wire conductors 1 from the wire conductor ribbon 2 fed to this illustrated arrangement, a metal sheet is first pregrooved on one or both faces to form wire conductors 1 that are connected by webs after grooving, then undergo a flexing process such that the webs are transformed into thin frangible webs that are easily separable from each other to form smooth and nearly burr-free edges. During this flexing process, each web undergoes repeated bending deformation about its longitudinal axis such that incipient cracks are formed by fatigue failure in the webs to convert them into the frangible web that can be opened locally.

In the arrangement of FIG. 1, this thus created wire conductor ribbon 2 first passes through a separating roller pair 3 that separates wire conductors 1 that are still connected to each other by frangible webs or residual frangible webs. A roller unit 4 positioned downstream of the separating roller pair 3 spreads the now separated wire conductors 1 as even-numbered and uneven-numbered wire conductors such that two arrays of spaced wire conductors 1 are formed. Since each of the two arrays now contains every second wire conductor from the original wire conductor ribbon 2, the result is that gaps, which each have approximately the width of a wire conductor 1 that is actually in the other group, are created between adjacent wire conductors 1 in each group.

These two arrays of wire conductors 1 then each pass through a deburring device 5 and are then reunited into a common group of wire conductors 1 between rollers of a drawing unit 6.

As is evident in particular in FIG. 2, the two deburring devices 5 are formed as combs having tines 6 whose edge faces form cutters for the deburring operation.

The wire conductors 1 are transported through the deburring station under tension, the drawing unit 6 generating the draw force also required to advance these wire conductors 1 while the separating rollers 3 and spreading rollers 4 generate a braking force, with the result that the requisite draw tension is created by the interaction of these devices that vertically orient the wire conductors 1 upstream of the deburring device 5 as a result of to resting gently on a horizontally disposed guide roller 7. The guide roller 7 furthermore suppresses vibration in the wire conductors 1.

Relative to their horizontal axes, the wire conductors 1 adjust themselves automatically for a uniform two-sided deburring operation since—due to the angles of the groove flanks—the cutting width that is set on both sides of wire conductor 1 by the cutting pressure is approximately equal, and the wire conductor is thus aligned centrally relative to the cutters of the deburring device. This self-alignment is most effective given a width/thickness ratio of 1:1, that is, when the width of the wire conductor is not too great.

Since refeeding of a new wire conductor ribbon 2 is laborious due to the required spreading of individual wire conductors 1, it is recommended that the process be operated using “endless” wire conductor ribbons 2. To this end, a welding station can be provided upstream of the separating roller pair 3, at which station the start of a new wire conductor ribbon 2 can be butt-welded on so that individual wire conductors 1 are aligned flush with each other. The welding bead formed here on the welding seam can then be ground flat on both edges of the conductor ribbon 2 using a method not shown in detail in the drawing, and the welding bead can also be removed at the grooves so as to ensure that subsequently at the welding seam it is also possible to separate wire conductors 1 from each other without difficulty.

As FIG. 3 shows, the tines 6 together with the cutters of deburring device 5 are oriented at an acute angle to the travel direction of the wire conductors 1 so that the cut line is somewhat increased, and the cutting pressure effected by the self-alignment of the wire conductors is thereby also increased, while the chips accumulated during deburring are also directed downward. In addition, the deburring device 5 is adjustable longitudinally of the tines 6, thereby allowing for readjustment whenever the cutters formed by the tines are dull in the working region.

Claims

1. A method for simultaneously deburring a multiplicity of wire conductors separated from a wire conductor ribbon and parallel to each other for producing round and shaped wires, wherein a sheet metal ribbon is first pregrooved on one or both sides so as to create the wire conductors of the wire conductor ribbon, after which the wire conductors still connected after grooving by webs undergo a flexing process so as to convert the webs into thin frangible webs that are easily separable from each other and that form smooth and nearly burr-free edges when detached, each web undergoing repeated bending deformation about its longitudinal axis in such a way that incipient cracks forming the frangible web are created by fatigue failure at the webs, wherein the frangible web can also be opened locally, characterized in that the wire conductors, after passing through a separating roller pair, are spread apart according to even-numbered and odd-numbered wire conductors by a spreading roller unit such that two arrays of relatively spaced wire conductors are created, wherein furthermore the two arrays of wire conductors pass under adjustable tension through respective deburring stations provided with respective deburring cutters, the draw tension being selected such that an automatic, central alignment, and thus a two-sided uniform removal of chips, is effected on the wire conductors due to the action of the groove-flank angle and of the adjusted angle of the deburring cutters, and wherein finally the wire conductors are reunited into a common group of wire conductors by rollers of a drawing unit.

2. The method according to claim 1, wherein the deburring station includes a comb-like deburring device that is provided with tines that form the deburring cutters.

3. The method according to claims 1 wherein the drawing unit downstream of the deburring station generates the draw tension intended for deburring as well as the draw force required to advance the wire conductors, and the separating roller pair and the spreading roller unit generate an opposing braking force, and both units are provided with guide grooves for the wire conductors.

4. The method according to claim 1 wherein the wire conductors are not subjected to restricted guidance in the horizontal plane so as to provide a uniform, two-sided deburring operation in the region upstream and downstream of the deburring station.

5. The method according to claim 1 wherein the wire conductors are guided vertically upstream of each of the deburring devices only under light applied pressure across one respective smooth guide roller.

6. The method according to claim 1 wherein the conductor ribbon passes through a welding station before entering the separating roller pair, in which station a new conductor ribbon is welded on when the end of a conductor ribbon has been reached such that the individual wire conductors are flush with each other.

7. The method according to claim 6, wherein the welding bead formed on the welding seam is ground flat on both sides of the conductor ribbon, and the welding bead at the grooves is also almost completely removed by an appropriately shaped tool by bilaterally and simultaneously grinding the top side and bottom side of the conductor ribbon.

8. An apparatus for carrying out the method according to claim 1, comprising: a deburring station for a conductor ribbon that is formed from a metal sheet in which wire conductors still connected by webs after grooving undergo a flexing process so as to then transform the webs into thin frangible webs that are easily separable from each other and form smooth and nearly burr-free edges when detached, whereby, after undergoing repeated bending deformation about their longitudinal axis, incipient cracks forming the frangible webs are created by fatigue failure at the webs, which frangible web can also be opened locally, wherein the deburring station includes a separating roller pair that separates the wire conductor ribbon into wire conductors, furthermore by a spreading roller unit in which even-numbered wire conductors are spread apart relative to uneven-numbered wire conductors such that two arrays of mutually spaced wire conductors are created, furthermore by a respective deburring device for each of the two arrays of wire conductors, as well asrollers forming a drawing unit in which the wire conductors are reunited into a common group, so that approximately the same tension acts on all wire conductors.

9. The apparatus according to claim 8, wherein the deburring device includes tines arranged like in a comb and forming deburring cutters.

10. The apparatus according to claim 9, wherein the tines are oriented at an acute angle to the travel direction of the wire conductors.

11. The apparatus according to claim 9 wherein the tines are oriented at an angle of approximately 45° to the wire conductors.

12. The apparatus according to claim 9 wherein the deburring device is adjustable in the longitudinal direction of the tines.

13. The apparatus according to claim 9 wherein the rollers of the spreading roller unit and the drawing unit are provided with guide grooves for the wire conductors.