EP2929950A1 - Wire drawing machine and method of drawing wire - Google Patents

Abstract

Wire drawing machine (1) for producing a drawn wire (12), in particular a drawn aluminum wire, with a housing (2), wherein inside the housing (2) at least one die (4, 6) is arranged and in the region of a wire outlet opening (8 ) of the housing (2) in the wire conveying direction (15) after all drawing stones (4, 6) a rinsing nozzle (9) is arranged, which rinsing nozzle (9) for generating a substantially against the wire conveying direction (15) directed jet of a rinsing fluid for rinsing the Wire (12) is arranged, wherein the Abspüldüse (9) for non-contact storage of the wire (12) is arranged, and method for producing a drawn wire (12) in such a wire drawing machine (1).

Description

The invention relates to a wire drawing machine for producing a drawn wire, in particular a drawn aluminum wire, with a housing, wherein at least one die is arranged in the interior of the housing, wherein in the region of a wire outlet opening of the housing in the wire conveying direction after all dies a Abspüldüse is arranged, which for Producing a directed substantially against the wire conveying direction jet of a rinsing fluid is arranged for rinsing the wire, and a method for producing a drawn wire in such a wire drawing machine.

In particular, the invention relates to a wire drawing machine integrated in an enamel wire system, that is, wherein the wire drawing machine is a part of the enamel wire system. In this case, a thin wire with a cylindrical cross-section is first drawn from a wire with a relatively large cross-section in several steps, which is then coated. In enamelled wire systems, the enamelled wire basically passes through the following main components: the removal device of the preferred wire, the drawing device with a wire drawing machine to realize a required bare wire, the annealing to recrystallize the cold-formed bare wire, the lacquerware for applying the lacquer film to the bare wire, the Einbrennschacht in baking oven for drying and hardening of the paint, the cooling system for controlling the wire temperature on the lacquerware and the winder for removing the finished enameled wire. The process conditions in the baking oven during paint drying, ie paint composition, solvent content of the circulating air, process air or wire temperature, drawing speed and flow within the furnace, are the decisive factors influencing the coating quality of an enameled wire. Basis for achieving the required quality of the final product in terms of mechanical and electrical properties is still the nature of the towed output wire prior to the painting process. In addition to the very high roundness of the cross section and consistent physical properties, this must above all have a very good surface quality over the entire wire length exhibit. The wire must have sufficient softness (elongation at break, springback) before the initial coating and must be free from dirt, linings and baubles (ie wire material removed by the wire during the drawing process). The wire drawing process is all the more important for the drawing, cleaning and annealing process.

During the drawing process, the so-called preferred wire with a correspondingly large raw wire diameter is first taken from a reservoir and fed via guide rollers or deflection rollers of the drawing system with one or more wire drawing machines. Such drawing machines usually have individually driven drawing disks over which the preferred wire is guided or tensioned. Due to the single drive of the drawing discs, slippage, which could damage the wire surface, can be minimized or even almost completely prevented. Between the drawing discs there are drawing blocks with conically shaped drawing stones, whose perforated cores are usually made of polycrystalline synthetic diamonds. The hole cross-sections of the cores decrease as the number of drawing heads increases, as a result of which the wire body is drawn and deformed or pulled through successively as it passes through the preferred wire. Due to the mechanical deformation of the wire in the drawing cones correspondingly low Enddrahtstärken can be realized.

The force with which a wire is pulled through the dies is applied via the drawing disks respectively behind the dies. The transmission of this tensile force from the pulley to the wire is done by friction. The frictional force depends on the material of the pulley and the wire, the condition and the geometry of the wire support surface, the number of wire wraps, the slip and the lubricant used. The dies are basically intended to enable high wire throughput speeds (high drawing powers) and to provide long service lives. The quality of the surface and the roundness of the drawn wire must always be within the permissible tolerances. The drawing cone itself is subject to high frictional pressure. The internal friction created during forming in the wire and the external friction in the wire Drawing cone therefore cause a strong warming. At the same time, a high-pressure flushing system with liquid drawing agent ensures intensive lubrication and cooling of the wire as well as the drawing dies. In addition, the drawing agent leads from the drawing machine caused by abrasion tinsel and other impurities. The liquid drawing agent / flake mixture is then continuously cleaned via a filter system (eg with a drum belt filter), which is part of a drawing agent circuit. Despite the flushing with the drawing agent, due to the high friction between the wire and the die core (high pressures), a mixture of drawing agent and tinsel is pressed into the wire surface. This has the consequence that on the wire firmly adhering organic drawdown residues appear, which are difficult to clean with conventional methods (stripping, chemical, etc.). These firmly adhering drawing agent residues can be thermally cleaned, for example, in a later annealing process.

Conventional wire drawing machines now have the problem that the last drawing die is wetted with drawing agent for lubrication and cooling before the wire runs in, but that the wire containing the tinsel and drawing agent is no longer cleaned after it has left the drawing die before it has been removed from the die so-called Ausziehscheibe arrives. Especially during the drawing process of soft aluminum wires, where far more material is removed than when drawing e.g. Copper wires, accumulate at the die exit and on the Ausziehscheibe correspondingly high amounts of metal baubles. These are pressed while guiding the wire over the Ausziehscheibe in the wire surface. The wire surface is thereby massively damaged and contaminated, as a result of which massive losses in coating quality have to be accepted.

The main reason for this problem is that the last drawing die of the wire drawing machine (also called end marker) sits directly within the framework of the housing or drawing cabinet of the wire drawing machine. This has next to the plastic rejuvenation of the bare wire also the task of the wire outlet of the To seal the drawing machine to prevent a discharge of high amounts of liquid drawing agent. The fact that the wire after exiting the last die, however, at the same time uncleaned metal baubles outward pulls, the consequences mentioned above.

The DE 2 434 109 A1 shows a lubricating nozzle for generating a directed against the wire conveying direction jet for lubrication and cooling of the continuous wire. The nozzle opening of the lubricating nozzle is accordingly spaced from the wire and arranged in the region of a drain opening to allow lateral outflow of the fluid.

It is an object of the invention to provide a wire drawing machine of the type mentioned, with which reduces damage to the wire on a Ausziehscheibe and the achievable in the sequence coating quality can be improved. At the same time a discharge of liquid drawing agent should be largely avoided.

To achieve this object, the invention provides that in a wire drawing machine of the type mentioned the Abspüldüse is set up for non-contact storage of the wire. Accordingly, the above object is achieved in a method of the type mentioned in that the wire is stored without contact in the rinsing nozzle. The wire is eg stored in a floating manner on a rinsing fluid cushion formed by the jet in the rinsing nozzle and the wire run is thus stabilized by the rinsing nozzle. The beam can thereby completely surround the wire or be guided all around parallel to a longitudinal axis of the wire and along the wire surface. The flushing fluid is preferably under high pressure, so that the jet has a high jet pressure. As a result of this and due to the jet direction directed counter to the movement of the wire, a high shear and thus an efficient removal, in particular of coarse-grained, of the wire surface are brought about. In particular, this makes it possible to use flake particles and liquid drawing agent on metal wires drawn by means of drawing dies after the last drawing die preferably coaxial conical fluid jets are cleaned on the basis of highest wall shear stress on the wire surface opposite to the wire running direction. In this case, preferably, a coaxial drawing agent jet is produced, which initially strikes the wire surface obliquely and then completely escapes at the wire inlet opening of the nozzle. Thus, not only flake particles are cleaned and transported away when the jet impinges on the wire, but also during the passage of the drawing agent along the annular gap between the wire surface and the nozzle wall at the inlet part of the nozzle. The emerging drawing agent jet from the wire inlet of the nozzle on the one hand contributes to the cleaning and on the other hand leads the wire at the same time non-contact and stabilizes him also. Due to the non-contact bearing naturally small gap widths between the wire surface and the nozzle wall additional wall shear stress on the wire for the removal of flake particles can be generated, resulting in a further improvement of the cleaning effect. Particularly favorable is the cleaning of the wire after passing the last die, since thus even the costs incurred in the last die baubles can be cleaned. The wire surface therefore advantageously has, after passing through the rinsing nozzle in addition to the non-cleanable, firmly pressed into the wire residues, only the rinsing fluid with particularly fine-grained bauble on; coarse flake particles remain in the drawing machine and do not get between wire and one of the drawing machine usually downstream Ausziehscheibe so that there caused damage to the wire is avoided. In addition, due to the contactless storage of the wire, damage to the wire through the cleaning process is avoided. Any transverse forces acting on the wire are thereby completely avoided, so that no harmful vibrations of the wire are excited. Preferably, the wire after the last die is guided without contact, ie in particular without further stabilization bearing, from the wire drawing machine.

In the intended use in a wire drawing machine, it is particularly advantageous if the flushing fluid for cooling the Wire is used drawing agent. If the same liquid is used as rinsing fluid and as drawing agent, the wire drawing machine does not require a new rinsing cycle for cleaning after the last drawing die, ie the wire drawing machine has only one rinsing cycle. The Abspüldüse is to generate the beam with liquid and hermaphroditic drawing agent, ie with filtered or purified drawing agent liquid from the drawing machine system itself, supplied. The removed by the jet of Abspüldüse baubles is preferably introduced into the drawing agent circuit of the drawing machine. That is, the exiting from the Absspüldüse drawing with the wire-cleaned particles remains in the drawing machine housing and runs there on the ground together with the drawing agent of previous dies in the cleaning or filter circuit.

In connection with the rinsing nozzle, it is particularly advantageous if, in the wire conveying direction downstream of the rinsing nozzle, a blow-off nozzle is arranged for producing an air jet directed essentially against the wire conveying direction for cleaning the wire of remaining rinsing fluid. Accordingly, it is also advantageous in the proposed method, if after flushing the wire remaining on the wire rinsing fluid is removed by means of a counter to the wire conveying direction directed compressed air jet from the wire. The Abspüldüse can be arranged offset in this case from the wire outlet opening into the interior of the housing. For example, the blower nozzle is operated with compressed air and blows compressed air against the wire movement around along the wire surface and parallel to the wire. The massive shear flow removes the blob / rinse fluid mixture remaining on the wire after the rinse nozzle and the wire comes out of the drawing machine with almost no liquid coating agent coating. Consequently, virtually no liquid drawing agent is dragged along with the wire to the pulley, so that the pulley results in a dry and clean wire, whereby ideal process conditions prevail in the wire guide itself and in subsequent sequence optimum coating quality is made possible. In the drawing machine As a result of the air jet generated by the blower blown air can escape eg through vents in the housing.

With regard to the blow-off nozzle, it has proved to be advantageous if it is arranged or seated directly in the wire outlet opening of the housing, so that the wire outlet opening is dynamically sealed by the air jet of the blow-off nozzle. In this arrangement, the flushing fluid, in particular the drawing agent, is enclosed in the housing in a particularly simple way, i. not discharged from the case.

Furthermore, it is particularly advantageous if the rinsing nozzle and / or the blow-off nozzle is or are an annular nozzle surrounding the wire and directed against the wire conveying direction. That the respective nozzle has a nozzle opening surrounding the wire in the entire circumference, from which the jet emerges. In order to determine the jet direction, the nozzle has one of the annular nozzle openings substantially parallel or slight angled towards the longitudinal axis of the wire tapered to the nozzle opening nozzle channel. This type of nozzle allows homogeneous and complete cleaning of the wire even with very small wire diameters (e.g., up to 0.25 mm) and centered support of the wire in a wire opening of the nozzle within and concentric with the annular nozzle opening.

In order to ensure a stable and reliable centering of the wire before entering the rinsing nozzle, it is also advantageous if arranged in the wire conveying direction in front of the rinsing nozzle Endziehstein is offset from the wire outlet opening into the interior of the housing. The Endziehstein, ie the last and narrowest die of the wire drawing machine is thus arranged in the wire conveying direction immediately in front of the rinsing nozzle, so that no deflection rollers between the Endziehstein and Abspüldüse are arranged. In addition, the Endziehstein, the Abspüldüse and possibly the Abblasdüse are aligned in a line so that the emerging from the Endziehstein or extended wire exactly through the center the rinsing nozzle and optionally the blow-off nozzle is guided.

Furthermore, it is advantageous if the cross section of a nozzle opening of the rinsing nozzle and / or the blow-off nozzle for the inlet of a rinsing fluid or an air jet to the wire is adjustable. The nozzle opening for the feed is inside the nozzle and is directed substantially (at an angle) against a wire conveyed through the nozzle. Different drawing machine configurations (inlet and outlet diameter of the bare wire, wire metal, wire diameter, wire speed, drawing die type, number of drawing dies, type of drawing medium, fat content of the drawing agent, etc.) lead to the formation of different tinsel amounts in different size distributions. In addition, different wire diameters result in different gap widths between the wire surface and the inlet part of the nozzle (ceramic insert) with different counter-pressures. In addition, different wire speeds require different drag effects and residence times of the wire. Therefore, different wall shear stresses are necessary on the wire surface in order to optimally clean the wire in all cases and to be able to ensure that the drawing agent jet exits the nozzle at a wire inlet side opening opposite to the wire feed direction. Due to the adjustability of the cross section of the nozzle opening, the nozzle or the wall shear stress achieved in the nozzle can be adapted to the respective prevailing conditions.

In this context, it has proved to be advantageous if the nozzle opening is formed between a nozzle body with an at least partially substantially conically tapering towards the wire conveying direction interior space for the transport of a rinsing fluid or an air jet and a guide member arranged at least partially in the interior, wherein the guide member is arranged adjustable relative to the nozzle body parallel to the wire conveying direction. In particular, the guide part can be displaceable parallel to the wire conveying direction relative to the nozzle body.

A reliable and accurate setting of the nozzle opening can be achieved if the guide member has an external thread with which it is screwed in an internal thread of the nozzle body about an axis parallel to the wire conveying direction. In this case, the nozzle opening can be adjusted by turning the guide member in the nozzle body.

In order to prevent or at least complicate movement of the guide member in the nozzle body after adjustment and to fix a fixed axial position of the guide member in the nozzle body, it is advantageous if a lock nut is screwed onto the external thread of the guide member, by means of which the guide member fixed to the nozzle body is. In this case, the guide member is tightened by tightening the lock nut substantially between the nozzle body and lock nut, so that a twisting of the guide member is counteracted.

• Fig. 1 eine schaubildliche Ansicht einer Drahtziehmaschine zur Herstellung eines gezogenen Drahtes;
• Fig. 2 schematisch einen Längsschnitt durch eine Abspüldüse und eine Abblasdüse einer Drahtziehmaschine gemäß Fig. 1; und
• Fig. 3 genauer einen Längsschnitt durch eine Abspüldüse gemäß Fig. 2.

The invention will be explained below with reference to particularly preferred embodiments, to which it should not be limited, and with reference to the drawings. The drawings show in detail:

• Fig. 1 a perspective view of a wire drawing machine for producing a drawn wire;
• Fig. 2 schematically a longitudinal section through a rinsing nozzle and a blow-off nozzle of a wire drawing machine according to Fig. 1 ; and
• Fig. 3 more precisely a longitudinal section through a rinse nozzle according to Fig. 2 ,

Fig. 1 shows a wire drawing machine 1, more precisely a so-called Inlineziehmaschine, with a housing 2 and a wire pre-cleaning system 3. In the housing 2, a plurality of dies 4 or drawing blocks are arranged, with which the wire (not shown) to the desired shape or the desired wire cross section is deformed. Between the dies 4, the wire is guided over each individually driven pulleys 5. The cleaning system 3 shown here is to rid the wire after passing the last die 6 (also called Endziehstein) of tinsel without liquid drawing agent from the wire drawing machine 1 is discharged. The Endziehstein 6 is on a special holder 7 fixed in the housing 2, so that the Endziehstein 6 not in the context of the housing 2 (also called drawing cabinet) sits, but offset inwardly in the housing 2 itself is placed. Between the Endziehstein 6 and the wire outlet opening 8 in the context of the housing 2, a Abspüldüse 9 is arranged, which applies correspondingly high pressure jets of liquid and tinsel-free drawing agent on the wire surface against the wire movement, ie reversed to the wire conveying direction. The resulting high shear causes an efficient removal, especially of coarse-grained tinsel from the wire surface, which is automatically introduced into a drawing agent circuit (not shown) of the wire drawing machine 1. The wire surface has after passing through the Abspüldüse 9 next to the non-cleanable, firmly pressed-drawing agent residues, only more liquid drawing agent with a particularly fine-grained tinsel. The Abspüldüse 9 is a Abblasdüse 10 with compressed air connected after (see. Fig. 2 ), which sits directly in the wire outlet opening 8 of the housing frame. The blow-off nozzle 10 blows compressed air against the wire movement. The massive shear flow achieved thereby not only removes any bauble / drawing agent mixture remaining on the wire after the rinsing nozzle 9 and feeds it to the main drawing agent circuit of the wire drawing machine 1, but also seals the wire outlet opening 8 of the wire drawing machine 1 dynamically. The particles cleaned off with the drawing agent jet generated by the rinsing nozzle 9 pass into a main drawing agent circuit of the wire drawing machine 1, whereby no new rinsing cycle has to be installed. The blown into the wire drawing machine 1 due to the air jet generated by the blower 10 air can escape through vents 11 from the housing 2.

On the basis of in Fig. 2 shown sectional view of the structure of the Abspüldüse 9 and the Abblasdüse 10 is more clearly visible. The two nozzles 9, 10 are arranged substantially centered on a straight line defined by a longitudinal axis of the wire 12, ie, the center of a wire channel 13 of the nozzle 9, 10 is in each case on the straight line. The two nozzles 9, 10 each have a nozzle body 14, which surrounds the wire channel 13 for the passage of the wire 12. In the nozzle body 14 is a conically tapered against the wire conveying direction 15 interior 16 is formed. In the interior 16 a beak-shaped guide member 17 is received, the inside of which forms a portion of the wire channel 13 and the outside of which - conically tapered against the wire conveying direction 15 - comparable to the interior 16, but slower, ie at a shallower angles against the wire channel 13. In the wire conveying direction 15, the inner space 16 is sealed by the guide part 17. The interior 16 has an inlet opening 18, to which a pressure valve 19 is connected. The introduced through the pressure valve 19 in the nozzle 9, 10 fluid, eg liquid drawing agent or compressed air, distributed in the interior 16 outside the guide member 17 and is pressed under pressure through an annular nozzle opening 20 between the guide member 17 and the nozzle body 14. Due to the shape of the nozzle body 14 and the guide member 17, the nozzle opening 20 has a ring cross-sectional area for the flow of the pulling means, so that the fluid in each case in an annular, the wire 12 substantially concentrically and uniformly surrounding beam exiting the interior 16, which beam continues along the wire 12 and for the most part exits through a front wire opening 21 of the nozzle 9, 10 from the nozzle 9, 10. By the directed from the Abspüldüse 9 on the wire 12 beam of liquid drawing agent (see the drawing agent flow along the arrows 22) are all, not pressed into the wire 12 residues, in particular coarse-grained tinsel, away from the wire surface and against the wire conveying direction 15 to Front 23 rinsed from the rinse 9. In the blow-off nozzle 10, which is arranged behind the rinsing nozzle 9 in the wire conveying direction 15, the compressed air introduced through the pressure valve 19 (see air flow along the arrows 24) is directed against the wire 12 through the annular nozzle opening 20 against the wire conveying direction 15 and blows any liquid drawing agent residues to the front 23 and through the wire opening 21 from the Abblasdüse 10. The emerging from the Abblasdüse 10 air flow or the compressed air jet forms at the In the wire conveying direction 15 after the blow-off nozzle 10, the wire 12 is usually taken up by a pulley (not shown) and pulled out of the wire drawing machine 1 (see FIG. Fig. 1 ).

Fig. 3 shows the rinsing nozzle 9 according to Fig. 2 more in detail. The guide member 17 is axially, ie parallel to the wire conveying direction 15, relative to the nozzle body 14 slidably, which is provided by a provided in a cylindrical portion of the guide member 17 external thread 26 which is screwed into a provided in the nozzle body 14 internal thread 27. The guide member 17 is thus axially displaceable by turning with seat in the internal thread 27 of the nozzle body 14 so that between the nozzle body 14 and guide member 17 different ring cross-sectional areas are released for the nozzle opening 20 and the cross section of the nozzle opening 20 is thus adjustable. The different settings lead to different fluid velocities and therefore also to different wall shear stresses on the wire at a given draw agent flow (pressure), so that it is possible to react to specification changes during wire drawing. In addition, a counter nut 28 with an internal thread for seating on the external thread 26 of the guide member 17 is an operating aid for rotating the guide member 17 without having to touch its external thread 26 by hand. By tightening the lock nut 28, the guide member 17 can be fixed in a certain axial position.

Claims (12)

Wire drawing machine (1) for producing a drawn wire (12), in particular a drawn aluminum wire, having a housing (2), wherein inside the housing (2) at least one die (4, 6) is arranged, wherein in the region of a wire outlet opening ( 8) of the housing (2) in the wire conveying direction (15) after all dies (4, 6) a Abspüldüse (9) is arranged, which for generating a substantially against the wire conveying direction (15) directed jet of a rinsing fluid for rinsing the wire (12 ) is set up, characterized in that the rinsing nozzle (9) for non-contact storage of the wire (12) is arranged. Wire drawing machine (1) according to claim 1, characterized in that the flushing fluid is a drawing means used for cooling the wire (12). Wire drawing machine (1) according to claim 1 or 2, characterized in that in the wire conveying direction (15) after the rinsing nozzle (9) a blower nozzle (10) for generating a substantially against the wire conveying direction (15) directed air jet for cleaning the wire (12). is arranged by remaining flushing fluid. Wire drawing machine (1) according to claim 3, characterized in that the blow-off nozzle (10) is arranged directly in the wire outlet opening (8) of the housing (2), so that the wire outlet opening (8) is dynamically sealed by the air jet of the blow-off nozzle (10) , Wire drawing machine (1) according to one of claims 1 to 4, characterized in that the rinsing nozzle (9) and / or the blowing nozzle (10) is a ring nozzle (s) surrounding the wire (12) and directed against the wire conveying direction (15) . are. Wire drawing machine (1) according to one of Claims 1 to 5, characterized in that a wire conveying direction (15) projects in front of it the Abspüldüse (9) arranged Endziehstein (6) of the wire outlet opening (8) into the interior of the housing (2) is arranged offset. Wire drawing machine (1) according to one of claims 1 to 6, characterized in that the cross-section of a nozzle opening (20) of the rinsing nozzle (9) and / or the Abblasdüse (10) for the inlet of a rinsing fluid or an air jet to the wire (12). is adjustable. Wire drawing machine (1) according to claim 7, characterized in that the nozzle opening (20) between a nozzle body (14) with an at least partially substantially conically tapered against the wire conveying direction (15) interior space (16) for the transport of a flushing fluid or a Air jet and an at least partially in the interior (16) arranged guide member (17) is formed, wherein the guide member (17) relative to the nozzle body (14) parallel to the wire conveying direction (15) is adjustably arranged. Wire drawing machine (1) according to claim 8, characterized in that the guide part (17) has an external thread (26) with which it can be screwed in an internal thread (27) of the nozzle body (14) about an axis parallel to the wire conveying direction (15). Wire drawing machine (1) according to claim 9, characterized in that a counter nut (28) is screwed onto the external thread (26) of the guide part (17) by means of which the guide part (17) can be fixed relative to the nozzle body (14). A method for producing a drawn wire (12), in particular a drawn aluminum wire, in a wire drawing machine (1) with a housing (2), wherein inside the housing (2) at least one die (4, 6) is arranged, wherein the wire (12) after passing all of the dies (4, 6) of the wire drawing machine (1) in a direction of a wire conveying direction (15) counter directed jet of flushing fluid from a Rinsing nozzle (9) is cleaned, characterized in that the wire in the rinsing nozzle (9) is mounted without contact. A method according to claim 11, characterized in that after the cleaning of the wire (12) on the wire (12) remaining rinsing fluid by means of a counter to the wire conveying direction (15) directed compressed air jet from the wire (12) is removed.

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