EP3011082A1

EP3011082A1 - Apparatus for electrolytic or electrochemical action on wire

Info

Publication number: EP3011082A1
Application number: EP14752367.4A
Authority: EP
Inventors: Michele Lapelosa; Gianpaolo ORLANDO
Original assignee: Assembling Srl
Current assignee: Assembling Srl
Priority date: 2013-06-21
Filing date: 2014-06-21
Publication date: 2016-04-27
Also published as: ITMO20130180A1; WO2014203072A1

Abstract

An apparatus for electrolytic action or electrochemical on wire, comprising a basin (8, 65, 73) within which is placed to slide the wire (4) in treatment; in the basin being present as electrolyte a connecting solution of the wire in treatment; an electrode that winds the wire at distance; an electrolytic action is applied between the wire in treatment, wire directly connected to an article of an electric circuit, and the electrode placed in the connecting solution to activate the electrolytic action, connected to the other head of the electric circuit; characterised by this that the electrode (21, 28, 31, 33, 37, 61, 68, 75) includes material to high electrical conduction and is placed in close contact from the surface in treatment; the used electrolytic solution is interposed between the electrode and the surface of the wire (4) in treatment to activate the electrolytic action, but also to constitute insulating meatus between electrode and wire in treatment; the proximity between the material to high conduction and the metallic wire generates micro discharged electrical in followed to micro short circuits between the material to high conduction and the wire. They are, moreover, described electrode constructive various forms, both for treatment apparatus in an intermittent way, and machine inserted in a continuous group of production and/or of drawing the wire continuously.

Description

APPARATUS FOR ELECTROLYTIC OR ELECTROCHEMICAL ACTION ON WIRE

Field of the invention

This invention relates to an apparatus for electrolytic or electrochemical action on metal wire, namely an apparatus that when operating removes the processing superficial residues of oxides and dirt patinas from a metal wire made in a continuous drawing group with the pickling, electrolytic action, or it applies an oxidizing, blackening or even electro-deposition, electrochemical action, besides the cleaning action. The apparatus being intended to be autonomous, that is, operating as a machine separated from the drawing group, as on wires with the most varying shape, or integrated in the same group to carry out the treatment action on the metal wire in the most appropriate production phase. Known art

The background art includes various solutions of electrolytic action basins for the pickling of the wire made in the continuous plants, they predominantly consist of basins with electrolytic etching solution where the wire is made perform several evolutions, in its continuous production motion, by means of multiple returns and in sequence in the wire path in such a way as to maintain the wire in the electrolytic solution, for a predetermined time to allow the pickling action on the wire, that necessarily occurs by means of the considerable volume of the electrolytic solution present in the basin. This constructive form causes a considerable dimension of the pickling basins due to the need to maintain therein a considerable length of the wire being processed, considering the slowness of the pickling action and the opposite continuous metal wire processing high speed of the plant with multiple turns maintained in the basin and developed in the length of the same.

In the art, from the document FR 2 648 734, overcoming the aforementioned pickling basins shape by using an electrolytic cell in which the wire produced in continuous enters and acts as electrode of the cell is known. The other electrode having a tubular shape, cut on the upper part, for the insertion of the wire to be pickled, within which the wire slides at the processing speed provided by the plant. This electrolytic cell operates with high tensions and the dimension of the pipe cannot be reduced to minimum values, in such a way as to allow the tension reduction, for the danger of forming discharging arches between the wire and the tubular electrode, that thus would create short circuit and the loss of the cell pickling action.

In fact, the main limit of the solution described in the previous document is the shape of the cell, namely of the tubular metal electrode that, in order to operate with a fair capacity of pickling or cleaning of the wire that crosses it, must operate with high tensions between the electrode and the wire. The apparatus in it described works on wire productions of the order of 1-2 mm of diameter starting from origin wire of 7-8 millimetres. In the case of not-cylindrical shaped wires, instead of the declared electro-technical wires, the aforementioned electrolytic cell presents said limits preventing the correct execution of the cleaning and of the pickling with irregular wires in the longitudinal and side development, as the wires of the foldable metallic clips.

In the background art the document JPH 10046400 in which is described a method and clearing device of a metal wire by means of an electrolytic cell in which the wire is placed in a way to cross a first portion of tubular cell, that constitutes the cathode without contacting the internal surface of the tubular electrode, but the same together with the wire is placed in immersion in the cell; the first portion of the cell ends without contacting the electrode constituting the anode, namely a contact mediated by the electrolytic solution between the cathode and the metallic wire is known. Then, immediately in sequence a second portion of electrolytic cell is placed with the metallic wire inserted in the second tubular electrode that is connected to the anode of the electric activation circuit of the cell and the electrolytic solution fills the tubular electrode and submerges completely the wire and the basins of the cell portions. To activate the electrical contact between the metal wire and the electrolytic solution in the end portion of the tubular first electrode a greater concentration of passing holes with the basin of the cell end portion is realized. Likewise in the second tubular electrode the series of passing holes is made in its initial portion with greater concentration, in such a way as to ensure a most effective contact of the solution with the metal wire that crosses the cell in the feeding motion for the treatment.

The described arrangement certainly ensures to avoid a short circuit between the electrodes, cathode and anode, just because they are housed in different portions of the electrolytic cell and the metal wire is the only means that is inserted into both portions. This arrangement therefore does not allow a making of the electrolytic action apparatus that is limited in the sizes and that could be placed indifferently both in line, with a drawing line of the metal wire, and as separate unit and set with an off-line autonomous and independent functioning. Moreover, the electrolytic action is always mediated by the solution used and the proximity between an electrode and the wire, that only after the passage in the first cell portion is charged with electric polarity and, in the passage in the second cell portion is subjected to the electrolytic action, well detached from the internal surface of the tubular electrode to avoid, as said the short circuit.

In the art the document US 3,619,382 in which is described a reduction process of metal compounds in a matrix by means of the electrochemical action of an electrode made up of anode and cathode on a movable head and placed to slide on the surface to be treated when immersed in an electrolytic solution suitable for the action on its surface is also known. The electrode presents a pole, the cathode, endowed with thin metal filament ends or even conductors of electric current as the carbon fibres, in particular the graphitized ones, which are most elasticized in such a way as to maintain a more rigid shape for spring-back. The electrode is made so that the anode is never in contact neither with the surface to be treated nor with the fibres or thin filaments constituting the cathode and that these could slide on the surface to be treated that is in contact with the anode only through the electrolytic solution; moreover, in the so combined electrode there are holes for the escape of the gas produced in the treatment.

Also in this case the ends conducting the electric current on the surface to be treated are spaced in order not to originate short circuit sparks, only the continuity created by the electrolytic solution allows the action required on the surface being treated.

Finally, the devices known up to now, for what mentioned above do not allow a versatility in the type of metal wire to be treated, being related to the shape of the volume of the electrolytic cell where the electrodes operate. Finally, in the known fittings the actions of different electrochemical treatment, with appropriate electrolytic solution, as the pickling, the oxidizing, the blackening and also the electro-deposition of metals, must occur on different fittings each intended to the different treatment action without having a possible conversion with the same apparatus that could, when required, perform different electrochemical or electrolytic actions. This background art is susceptible of important improvements with regard to the possibility to realize an apparatus for electrolytic or electrochemical action on metal wire, that overcomes the aforementioned limits of the known art, executing a new electrolytic cell shape for the apparatus for the pickling and cleaning of the metal wire, that could be adapted to the specific treated wire and to its starting condition, as well as being versatile for the different type of treatment which the metal wire requires.

The technical problem, therefore, that is at the base of the present invention is to realize an apparatus for electrolytic or electrochemical action on metal wire, that allows a versatility in the typology variation of the treated wire and, moreover, that realizes the electrochemical or electrolytic treatment operation using limited tensions between the electrode in the bath and the wire or even null distances between the metallic wire, connected with a polarity, and the electrode with opposite polarity.

An aim included in the previous technical problem is to realize shapes of the electrode that can be adapted to multiple shapes of the metal wire to be treated, moreover, that in these same could be allowed tensions and currents which are not-unlike between the different types of electrode.

An additional and further aim of the present invention is to allow in addition to the pickling and cleaning also other electrochemical action operations such as the blackening and the wire coating with its oxide or even the electro- deposition of metals. Another aim oriented to the application versatility of the apparatus of the present invention, but not less important, regarding the over exposed technical problem, relates to the insertion of the apparatus in a continuous line of metal wire-drawing, namely making it part of the same line and avoiding, thus, the unwinding and rewinding operations of wire for bobbins, typical of the off-line working.

Finally, a further part of the technical problem and of completion of what above exposed refers to the need to make null the damage of the electrode in correspondence with the continuous passage of metal wire for the treatment and also to make its possible replacement practical, easy and fast.

Summary of the invention

This problem is solved, according to the present invention, by an apparatus for electrolytic action on metal wire, comprising a basin within which is made slide the metal wire in treatment; in the basin being present as electrolyte an etching solution of the wire in treatment; an electrode that winds the wire at distance; an electrolytic action is applied between the metal wire in treatment, wire directly connected to a lead of an electric circuit, and the electrode placed in the etching solution to activate the electrolytic action, connected to the other lead of the electrical circuit; characterised in that the electrode includes material with high electrical conduction and is placed in narrow contact from the surface in treatment; the electrolytic solution used is interposed between the electrode and the surface of the metal wire in treatment to activate the electrolytic action, but also to constitute insulating meatus between electrode and metal wire in treatment; the proximity between the material with high conduction and the metal wire generates electrical micro discharges following to micro short circuits between the material with high conduction and the metal wire.

In an additional constructive form the electrode presents the material with high electrical conduction in the form of filaments present in the components of the electrode or constituting the electrode itself in all or partly when dispersed or as covering of other flexible or rigid material.

Moreover, in a specific execution the electrode presents said filaments made up of wires in carbon fibre.

Moreover, in an additional constructive form, the wires in carbon fibre are placed free as a brush near the surface of the wire in treatment.

Moreover, in an improved specific execution the wires in carbon fibre are placed to constitute a tissue or braiding associated to the electrode put in contact with the surface of the wire in treatment.

Moreover, in an additional constructive form the filaments with high electrical conduction are made with wires in carbon fibre placed immersed in a tissue, wire or braiding in insulating material and placed in proximity or contact surface of the metal wire in treatment.

Furthermore, in a specific execution, the wires in carbon fibre of the tissue or braiding, constituting an electrode immersed in the electrolytic solution under the level of this latter, cover a rigid body that is not put in contact with the metal wire in treatment.

Moreover, in an additional constructive form, the wires in carbon fibre of the tissue braiding, constituting an electrode immersed in the electrolytic solution under the level of this latter, cover a body in insulating material and resistant to the sliding mechanical action in the contact with the metal wire in treatment.

Moreover, in a specific execution, the wires in carbon fibre of the tissue braiding, constituting an electrode immersed in the electrolytic solution under the level of this latter, cover a body in flexible insulating material and resistant to the sliding mechanical action in the contact with the metal wire in treatment.

Moreover, in a constructive additional variation, the tissue or the braiding is tube-like shaped and the metal wire in treatment is introduced and surrounded by the tube-like shaped electrode.

Moreover, in a specific constructive form, the tissue or the braiding is made as a wound strip to form a tube wound on the metal wire in treatment and stopped by interrupted rings.

Moreover, in a specific structure, the electrode, made in material however conductor of the electric current, is coated of woven insulating material, interposed between it and the wire in treatment, so being able to be approached to the surface in treatment of the metal wire. Moreover, in a specific preferred execution, the wires in carbon fibre are immersed in a wire and form the same wire, completely in carbon fibre, so to constitute an electrode in the form of wire, that is placed wound as a spiral on a portion of the wire in treatment, immersed in the basin with the electrolytic solution suitable for the needed treatment; the wire constituting the electrode is released on one side of the portion from an unwinding bobbin and is picked up, that is wound, on the opposite side on a rewinding bobbin; the wire constituting the electrode is wound as a spiral on the metal wire in treatment and is rewound with motion in a direction opposite to the advancement motion of the wire in treatment.

Moreover, a machine execution is conceived in such a way that the metal wire in the passage in the treatment basin is subjected to the treatment in following basins in its path; moreover the passage between a basin and the following one occurs by a return of the same wire several times in different and parallel passage paths in at least a pair of basins in sequence.

Finally, in an execution for high production the aforementioned basins are placed at different levels with an upper basin and a lower basin and at least one pulley that deviates the wire/s between the two basins.

Further features and the advantages of the present invention, in the execution of an apparatus for electrolytic or electrochemical action on metal wire, will be shown from the description, made in the following, of embodiments examples having an indicative and non-exhaustive title with reference to the fourteen enclosed drawing tables. Brief description of drawings

Figure 1 represents a sideway schematic view of an apparatus, according to this invention, in the constructive form with separate functioning from a continuous wire production plant;

- Figure 2 represents a plan schematic view of the apparatus of previous Figure 1 ;

- Figure 3 represents a longitudinal cross-section view of the basin of the apparatus of previous Figures; - Figure 4 represents a schematic section IV-IV of Figure 3 to show the position of the wire in treatment inside the basin and the level of the electrolytic solution;

- Figure 5 represents a schematic section, similar to the section IV-IV of Figure 3, in which is represented a first constructive form of electrode according to the found of the present invention, comprising filaments in carbon fibre distributed on the length of the wire portion within the aforementioned basin, placed immersed in the electrolytic solution and in contact with the wire;

- Figure 6 represents a schematic section, similar to the section IV-IV of Figure 3, in which is represented a second constructive form of electrode according to the present invention, comprising a section in pairs of metallic buffers of the electrode coated in insulating tissue, however porous, extended on the length of the metal wire portion within the aforementioned basin;

- Figure 7 represents a schematic section, similar to the section IV-IV of Figure 3, in which is represented a third constructive form of electrode according to the present invention, comprising a tubular section of the electrode in insulating tissue with inserted wires in carbon fibre, subtended on the length of the metal wire portion within the aforementioned basin;

- Figure 8 represents a limited plan schematic view of the third constructive form with the electrode with tubular section;

- Figure 9 represents an enlarged schematic section T-T of Figure 8 of the wire in treatment and of the electrode with tubular section;

- Figure 10 represents a limited plan schematic view of a variation of the third constructive form with the electrode with tubular section here wound by a strip of material in insulating tissue with inserted wires in carbon fibre;

- Figure 11 represents an enlarged schematic section T-T of Figure 10 of the metal wire in treatment and of the electrode with tubular section wound by strip of material in insulating tissue with inserted wires in carbon fibre;

- Figure 12 represents a plan schematic view of the basin of the apparatus of a fourth constructive form of spiral-like electrode wound on the metal wire in treatment, in which the unwinding and rewinding bobbins of the spiral-like electrode wound on the wire are represented; - Figure 13 represents the schematic shape of the spiral-like electrode wound on the metal wire in treatment and of the power-operated picking bobbin of the electrode itself in a motion opposite to the sliding motion of the wire in the electrolytic treatment basin as visible in the fourth constructive form;

- Figure 14 represents a schematic view of a machine for the electrolytic treatment of the metal wire with a treatment basin split in an upper one and a lower one, here being a multi-wire one, to house more portions of the same metal wire in treatment, but to increase its length and therefore the effectiveness of the applied treatment also at passage higher speeds, being the same wire sprung back from a pulley to the other within the two basins and successively in the washing and drying basin;

- Figure 15 represents a plan schematic view of the machine of Figure 14 with the washing and drying basin of the wire coming from the same machine being visible;

- Figure 16 represents a longitudinal schematic section of the basin of

Figure 14 suitable to house a plurality of wires, in parallel and at the same level, with sliding of the wire on the underlying electrode with a polarity of the treatment, while the other electrode being connected to the same wire, in such a way as to have an infinitesimal distance between the wire in treatment and the material constituting the electrode;

- Figure 17 represents a longitudinal schematic plan view of the basin of previous Figure 16 with the rigid longitudinal electrode coated with material constituting the electrode;

- Figure 18 represents a XVIII-XVIII schematic section of Figure 16, enlarged to show the arrangement of the lower electrode and a strip in insulating material, for the spacing of the wires in treatment from the underlying electrode to show a fifth constructive form;

- Figure 19 represents a schematic section of a cloth in soft insulating material and coated by an external layer of conducting material as a braiding in carbon fibre to constitute an electrode to be used also in the constructive form of previous Figure 6, or the like;

- Figure 20 represents a schematic section of a further constructive form in which the electrode includes a rigid material with the wound braiding in carbon fibre similarly to the constructive forms visible at the Figures from 5 to 7;

- Figures 21 and 22 are images obtained with the electronic microscope of a surface of a first sample of not-treated metal wire, Figure 21 , and a treated one, Figure 22, before and after the electrolytic cleaning treatment of the wire with the apparatus of Figure 14;

- Figures 23 and 24 are images obtained with the electronic microscope of a surface of a second not-treated sample of metal wire, Figure 23, and a treated one, Figure 24, before and after the electrolytic cleaning treatment of the wire with the apparatus of Figure 14;

Finally, Figure 25 is an image in greater blow-up of the result of the electrolytic cleaning treatment in which only residues of matter foreign to the surface of the wire remaining in the micro-hollows evidenced in the circled points are visible.

Detailed description of preferred embodiments

In the Figures 1 and 2 a bench 1 , as supporting structure, the parts constituting the apparatus 2 in the constructive form for an use separate from a continuous drawing and production line can be seen. On the bench there are a bobbin 3 for unwinding the metal wire 4 to be treated, a bobbin 5 for rewinding the wire, some driving gears 6 for guiding the wire 4 in a prearranged position on the bench 1 ; the path of the wire is completed by a rewinding device 7, that places the wire on the bobbin 5, for a correct completion of its layers. The apparatus 2 includes a basin 8, within which the metal wire 4 slides at the prearranged height and is immersed in electrolytic solution for the electrochemical treatment required; the basin 8 ends with a drying group 9; the wire exited from the drying group of the basin 8 enters thereupon in the washing basin 10 and exits from this latter through an additional drying group 11 , before engaging the driving gear 6 downstream and the rewinding device 7. At the basin 8 a pipe 12 introduces the treatment electrolytic solution, that maintains the level imposed by the end weirs 13 of the basin and the exceeding solution is collected in a respective discharge compartment 14, present upstream and downstream of said weirs 13; a corresponding pipe 15 conveys the exceeding solution from said discharge compartments in the collection container 16 of the treatment electrolytic solution. In the same way the washing basin 10 presents a pipe 17 that introduces the washing water in the basin, the end weirs 18 of the basin maintain the level and the exceeding water is collected in respective discharge compartments 19, present upstream and downstream of said weirs 18; a corresponding pipe 20 conveys the solution in a container/installation of collection and/or treatment of the washing water, here not represented.

In the Figures 3 and 4 it can be seen as the wire 4 crosses the basin 8, always at the same height determined by the height of the weirs 13 and by the passage slumped point of the metal wire 4 in the weirs; the exceeding electrolytic solution flows through the weirs 13 in the discharge compartments 14, always maintaining the same level L in the basin 8 determined by the weirs and allowing the metal wire 4 to remain immersed in solution for the whole length of the basin 8, that is in the portion between the weirs 13.

In the Figure 5 a first constructive form characterised by an electrode 21 , as visible in the previous Figure 2, supported in the length of the basin by arms 22 can be noticed. Each electrode is made by linear brushes 23 placed aligned to the path of the metal wire 4 in the basin 8. Each brush ends with a plurality of wires in carbon fibre 24 that extend near the metal wire 4 in its path within the basin 8, between the weirs 13 and immersed in the treatment electrolytic solution; the brushes have only the conductor wires in carbon fibre immersed and are in contact with the wire in treatment, as visible in the Figure 5, but the motion of the metal wire 4 and the consequent swaying of the carbon filaments limit the electric discharges in short circuit, carrying out at the same time the desired electrolytic action.

In the second constructive form shown in the Figure 6 a couple of linear electrodes 28 is approached sideways to the metal wire 4 immersed in electrolytic solution of level L; the electrodes are sustained by arms 22, as the electrodes of the brush constructive form 23 and have a coating in woven insulating material 29, or anyway permeable, so as to let pass the electrolytic solution between the electrode 28 and the wire 4 in treatment without carrying out an effective contact between electrode and wire. Advantageously, the insulating material 29 presents a thickness from few tenths of millimetre to few millimetres and in the experimentations resulted useful a woven material in PEEK (polyetheretherketone) trade name of the Dupont, for the high heat resistance without carbonizing that identifies it. With this constructive form the winding of the electrochemical action is complete and made at the minimum distance allowed by the thickness of the same insulating material. Moreover, the insulating material 29 is fixed to the body of each electrode 28 by means of fastening elements 30 that allow the replacement of the insulating material, if overly worn out for the sliding on the metal wire 4 in treatment. Each electrode 28 can advantageously be made up of graphite or similar conducting material resistant to the used electrolytic solution. Moreover, the arrangement of the electrodes 28 can be spaced of one or two millimetres with respect to the surface of the wire, in such a way as to allow the treatments similar to those of the previous constructive form, the electro-deposition included. Even if in this constructive form is possible to replace the electrodes, the maintenance with the change of the worn out insulating material occurs off line, allowing to stop a continuous drawing line for a short period; or, also to avoid the stopping, for the replacement of an electrode 28 that is necessary, of the production line if in the basin more portions are placed, of couples of coated electrodes 28, in sequence: the replacement occurs every single portion of electrode maintaining the wire 4 in continuous motion.

In the third constructive form of Figures from 7 to 11 between two arms 22 is subtended an electrode 31 wound on the wire 4 in treatment, made with a coating small tube 32, composed of woven insulating material with different inserted filaments in carbon fibre, in such a way as to make the tissue electrically conductive; the small tube 32 must be inserted in a lead of the wire 4 in treatment, in such a way as to need the stopping of the apparatus for the introduction of the metal wire 4 in said small tube; the small tube 32 with the wire inside, then, is fixed between two arms 22 of the portion of the small tube-like electrode 31 immersed in the basin 8. In the constructive variation of Figures 14 and 15 a small tube 33 is made by winding of a portion of insulating tissue 34, always with the wires in carbon fibre in its inside, that is fixed so wound by a strip with interrupted rings 35, placed in intermediate positions between the end arms 22 of a wound small tubelike electrode 36.

In the Figures 12 and 13 is shown a fourth constructive form in which a wire in insulating material 37 having inside wires of carbon fibre, in such a way as to make it a conductor, is unwound by a bobbin 38 and wound as a spiral with various turns around the metal wire 4 in treatment inside the basin 8; a successive bobbin 39, power-operated by an electrical ratio-motor 40, winds the wire in insulating material 37, that has been in contact with its own turns on the metal wire 4 in treatment; advantageously, the winding and advancement motion of the wire in insulating material 37 is opposed to the advancement motion A of the metal wire 4 in treatment in the basin with the electrolytic solution 8.

In the Figures 14 and 15 the application of the arrangement in contact and at very-short distance with the electrode from the wire is made for a machine 41 placed in a continuous drawing line of metal wire 4. The machine presents a couple of basins 42 and 43 with multiple passages of the metal wire 4 in each of them, then the arrangement with the upper basin 42 and the lower basin 43 allows to obtain said multiple passages with a minimum encumbrance with the spring back carried out between a basin and the other by the pulleys with multiple grooves 44. The wire 4 enters on one side 45 of the machine 41 and passes with a first passage in the upper basin 42 and with the return of the pulley 44 on the opposite side returns with the passage in the lower basin 43. The sequence of the returns between the pulleys allows to develop much the length of the wire in treatment within the two basins 42 and 43. The machine 41 shown makes a series of six passages of the wire 4 in each upper basin 42 and lower basin 43.

The wire 4 so treated exits from the basins at the top 46 of the machine and with a spring back 47 enters the washing and drying group 48 then with a following spring back 49 continues the path provided by the drawing line. The washing group presents a basin 50, limited by two ^"upstream and downstream weirs 51 , continuously fed by the washing water from the pipe 52 and the exceeding water is collected by the drains 53 as described in the basin 10 of Figures 1-3; so in the drying part the wire crosses a sequence of drying groups 11 in its exit path from the machine 41. In the Figure 15 are shown also the treatment portions 54 of the electrolytic solution, for the basins 42 and 43, and the water, for the washing and drying basin 48, portions that are known and therefore not further described.

The assembly of the two described basins, upper one 42 and lower one 43, is represented in the figures 16-18 in which the single multiple basin 55 presents end weirs 56 equipped with an upper wall 57 to limit the upper passage to the weirs and therefore to limit the reflux of the electrolytic solution in exit. The electrolytic solution that exits both from the weirs 56 and from the blow-by from the underside of the single basin from holes 58, of which is equipped the bottom 59 of each basin, falls or drips G below this basin: for the upper basin 42 the dripping occurs in the underlying basin 43 and from this, instead, the dripping G and the solution exiting from the weirs 56 is collected in the collection basin 60 underlying said basins, visible in Figure 14, for the recirculation in the portions 54 of machine intended for the treatment of the electrolytic solution used. The bottom 59 is wound by a layer 61 of tissue or braiding in carbon fibre, conductor, to constitute the electrode, for the contact with the metallic wire 4 in treatment, opportunely connected with the wire terminal of the electrical equipment with the pole opposite to the one put in contact with the wire, as described in the previous constructive forms. The body of the bottom 59 is, advantageously, composed of rigid and insulating material on which the braiding or the tissue 61 in carbon fibre is wound. At regular spaces spacer 62 are placed, between the wires 4 that slide in the basin from end to end and said electrode in carbon fibre, they are in insulating material and resistant to the wire abrasion, as the Zylon (PBO) trade name of the Toyobo, or even the above-mentioned PEEK, in the form of felt small cloth to space out, precisely, the metal wire from the underlying electrode in carbon fibre. The spacers 62, four in the Figures, allow the wire to flex between a spacer and the following spacer, in such a way as to graze or even cut the carbon fibres of the layer 61 constituting the electrode. After the incision of the layer the continuous sliding of the wire generates an infinite series of micro short circuits between the fibres that, even if sheared, continue to conduct current towards the metallic wire that slides between them. The electric micro discharges so generated activate beyond measure the wanted electrolytic action without therefore damaging the carbon fibres, that do not wear with the repetition of the discharges and the spacer that, even if being in sliding contact with the wire 4, it does not wear if opportunely made with the above mentioned materials. The spacers 62, being flexible are laid on the bottom 59 of the basin against the layer 61 in carbon fibre and have the upper end ends 63 grasped by clips 64 to the side edges 65 of the relative basin 42 or 43, as visible in the section of Figure 8.

A variation, of the constructive form of coated electrode of Figure 18, is in the Figure 19 where a section of felt 66 or cloth in insulating material, as above, Zylon or PEEK, is coated with a tissue or braiding 67 in carbon fibre to constitute a composite small cloth 68 usable in electrodes as the one described in previous Figure 6, and the like. The contact with the metal wire, in crossing between the two coated electrodes of the composite small cloth 68, occurs as described for the sliding of the wire 4 in the aforementioned basins 42 and 43, so the minimum distance between the carbon fibres and the metal wire ensures the maximum electrolytic action of the micro electric discharges that generates, even if the carbon fibres are sheared by the sliding of the metal wire on them.

A sixth constructive form of electrode 70 is visible in Figure 20 in which the electrode, schematically represented, consists of two adjoining halves 71 which can be approached and adjusted with adjustable supports 72 both for the replacement of the two halves and for the adjustment on a specific wire to be treated. The basin 73 is similar to the basin 8 of Figures 1-3 and the two halves of the electrode 71 include each a conductor body 74 coated by tissue or braiding 75 in carbon fibre intended to come into contact with the metal wire 76 in treatment. The metal wire 76 placed to slide between the two halves 71 is not in contact with the conductor bodies 74, but only with the filaments of the carbon fibre of the tissue or braiding 75 that, for the sliding, get sheared and remain at a very-short distance from the surface of the metal wire. Also in this case the electrolytic action is obtained increased by the micro electric discharges between the sheared and fluctuating carbon fibres and the surface of the metal wire 76 that slides between them.

The functioning of the pickling apparatus with electrolytic action on the metal wire 4 occurs as specified in following for the described various constructive forms. The subtended metal wire 4 within the treatment basin 8 is dipped for its length and soaked by the electrolytic solution between the weirs 13; the continuous electrolytic solution contribution from the pipe 12 allows the maintenance of the level within the basin 8, even if from the weirs the solution overflows maintaining its level. The electrolytic solution that overflows is collected in the discharge compartments 14, and with the pipes 15 is flown in the container 16, so it can be made circulate by a pump, not represented, that draws the electrolytic solution from the container and sends it back in the electrolytic treatment basin. So the wire 4 that passes within the basin is subjected to the action of specific electrodes, described in the constructive various forms, connected to a conductor of the electric circuit activating the electrolytic action and the other wire of the circuit is placed in contact with the wire 4 in treatment. In this way it is possible to carry out on the metal wire 4, that transits in the treatment basin 8, different types of electrolytic treatment as the pickling, the blackening or covering of the surface with its oxide and also the electro-deposition of metals on the surface itself of the wire 4, in an intermittent way on the apparatus of Figure 1 or the like, or in a continuous way in a continuous processing line with the metal wire 4 that crosses an apparatus, as that of Figure 1 however lacking the bobbins 3 and 5 and of the rewinding device 7.

In the first constructive form of Figure 5 the electrodes transmit the electrolytic action to the solution by means of wires in carbon fibre 24 of the brushes 23: the wires are of infinitesimal diameter in such a way as to have a great surface wet by the electrolytic solution and the range of action towards the surface of the metal wire is very accentuated. In the positioning of the wires in carbon fibre the contact with the metal wire 4 in treatment is so obtained, moreover the contact is not continuous and is mediated by interposing the electrolytic solution itself in such a way as to minimize electrical arches of short circuit, for the continuous fluctuation of the wires in carbon fibre, due to combined motions of the solution and of the metal wire. This arrangement allows a very good result in the pickling action, while if applied to the blackening treatments of the metal wire with its oxide, oxidizing or even of electro-deposition leaves striations and irregularities on the treated surface of the metal wire also visible to bare eye, but that can however be accepted in relation to the aesthetic quality that the treated surface requires.

Likewise to what described for the constructive form with brushes 23, the constructive form with coated electrodes 28, of Figure 6, is advantageous for all the treatments, with the only limit of the continuity of the of the metal wire 4 external surface, that must remain and must not present asperities in the length of the metal wire while sliding within the two electrodes 28 opposed in the case of approach in contact with the coated electrodes against the metal wire 4 in treatment. Moreover, in the experimentation it has been verified the need of a preventive superficial de-greasing of the metal wire in treatment to avoid a fast fouling of the coating in insulating material 29 in the sliding contact on it, that otherwise needs a fast replacement. Moreover, it has been experimented that operating with said coated electrodes 28 at a short distance is possible, i. e. not in contact but one or very few millimetres distant from the surface of the metal wire 4. In this way also the blackening treatments of the metal wire with its oxide, oxidizing or even of electro-deposition become possible and obtained with a good surface quality, that is without the aforementioned deficiencies.

In the constructive form of closed 32 or 34 wound small tube-like electrode, of Figures from 7 to 11 , the electrolytic action is activated for the effect of electrolytic cell that is set regularly between the wires in carbon fibre, immersed in the insulating tissue of the same small tube, and the metal wire 4, that is the other pole of the electric circuit. The thin electrolytic solution layer, linked to the thin air space between the internal diameter of the small tube and the surface itself of the metal wire allows an effective electrolytic action however without generating directly a contact between the wires in carbon fibre and the surface of the metal wire 4 in treatment. In this way the pickling action, or blackening the metal wire with its oxide, oxidizing or even of electro-deposition is obtained.

As said in the description of the Figures, the small tube 32 needs introduction of the metal wire with idle apparatus, namely, it is most suitable for a treatment apparatus out of the production or drawing line, while the constructive form with the wound small tube 34 and the closing interrupted rings 35 makes easy and fast the replacement of the small tube also with the metal wire 4 tensioned in the treatment basin 8, namely it does not require to operate on one end of the wire in treatment. This constructive form is suitable to apparatuses placed and operating in a continuous processing line.

Moreover, in the fourth constructive form of Figures 12 and 13 the metal wire 4 in treatment can have any form also with asperities in the length of the same wire, so the wire in insulating material 37 mixed with wires in carbon fibre, that constitutes the electrode, makes in its spiral-like winding an electrolytic action similar to the shape of the small tube-like electrode described with the considerable advantage of the continuous replacement of the wire 37 constituting the spiral-like electrode. Thus this constructive form is advantageous for the insertion of the electrolytic action apparatus in a continuous operating production line, because the replacement of the insulating wire 37 with wires in carbon fibre, constituting the electrode, occurs in a continuous way by release of the insulating wire 37 from the bobbin 38 and its rewinding in the bobbin 39 placed in rotation by an electrical ratio-motor 40. In this way, also with this constructive form, the pickling action, or blackening the metal wire with its oxide, oxidizing or even of electro-deposition is obtained.

Thus, the operation of the multiple basins 42 and 43 occurs by sliding of the metal wire on the tissue or braiding in carbon fibre 61 that covers the body of the bottom 59, the sliding with support of the metal wires 4 on the spacers 62 in insulating material generates no damage of the same spacers because the material Zylon or PEEK is resistant to the continuous abrasion of the wire. The cut of the carbon fibres made by wire sliding generates no additional damage of the tissue or braiding 61 for the minimum elastic resistance of the same fibres that fluctuate in the electrolytic solution also in dragging to the motion of the wire and of the liquid of the solution. The variable distance of the ends of the carbon fibres from the contact with the wire at few tenths of millimetre allows to perform the action of the micro electric discharges between the surface of the metal wire 4 and the carbon fibres. The pickling and cleaning actions of the wire are made with greater effectiveness and in a very economical way seen the low electrical powers found to activate the required actions. ln the tests carried out the superficial status of the wire was detected, by detections at the electronic microscope on a metal wire with diameter of 1 millimetre, and the results are compared for two wire samples in the Figures 21 and 23, with mechanical usual cleaning of the wire, while in the Figures 22 and 24 the samples are shown in which besides the mechanical cleaning also the cleaning with the electrolytic solution in the described fittings was carried out. The presence of dirt particles, characterised by the elements of Sodium Na, Potassium K and Chlorine CI, in the untreated sample is extended also to the surface of the wire, while in the treated sample such elements are limited inside the deepest slots, as visible in the Figure 25, of an investigation by the electronic microscope with quadruple enlargement with respect to the previous detections. Only in the deep slots, enhanced with the hooping, it was possible to detect traces of residual dirt precisely because of the presence therein of the aforementioned chemical elements; the surface of the metallic wire resulted free from said elements which are indication of dirt.

In the experimentation carried out with the machine of Figures 14-18 the single wire 4 was made pass several times in a paired way in the respective upper 42 or lower 43 basin, by means of spring back with the multiple groove pulleys 44. Moreover a similar constructive form can be obtained, using the same basins 42 or 43 for the passage of a series of metal wires in treatment that travel in parallel and therefore that should not be rewound, but are part of a drawing line with multiple wires treated in parallel, that is, the basins being directly placed on the passage line of the metal wires in parallel.

Finally in the experimentation was noticed that the thickness of the cloth in insulating material, Zylon or PEEK, must be comprised between a minimum of 1 millimetre to a convenient maximum of 4 millimetres; with the preferred thickness not higher than 1 ,5 millimetres.

The advantages in the use of an apparatus for electrolytic action on metal wire, according to the invention, can be summarized as follows. With respect to the known art the apparatus described is of very reduced sizes because the required electrolytic treatment action is carried out in small basins with respect to those utilized with more spring back in the continuous productions. Moreover, the execution of an apparatus as described, that operates in a non-continuous way, allows to operate out of line on lots of variable products, that is with a maximum flexibility and possible rapidity. In fact an apparatus described executes the desired treatment by introducing in the basin 8 the electrolytic solution suitable for the same treatment, therefore with the replacement of the electrolytic solution the same apparatus can carry out different treatments; even more, it is possible to use in the same apparatus different electrodes and shapes of electrodes, in such a way as to make more practical and effective the desired electrolytic action on the metal wire 4 in treatment.

From the functional verification carried out it was noticed that the amount of present carbon fibres is correlated to the capacity of action of the treatment of the specific electrode used, for the greater wet surface that each fibre, of infinitesimal diameter, develops in the sum with the surfaces of the other fibres in carbon constituting the brush 23 or inserted in the insulating material of the insulating wire 37. The electrode 28, being instead of fixed surface, about parallelepiped like, if made with the portion conducting the superficial electric power and obtained with a metal surface or coating in conducting material, as a tissue with immersed carbon fibres, are these latter ones to determine the capacity of electrolytic action more or less effective on the surface in treatment. However, with the use of the described apparatus, both for out of production or drawing line treatments, or inside the same drawing groups results much more economical and effective than the known treatments, because the surface of the electrode wet from the solution used is directly correlated to the quantity of wires in carbon fibre used and to the possibility of maintaining a position at infinitesimal distance from the surface of the metal wire 4 in treatment in the passage inside the two coated electrodes 28.

So, also the treatment machine described and represented in the Figures 14-18 results versatile in the possibility to carry out, in addition to the pickling and/or cleaning treatment of the metal wire, also possible electrochemical treatments as the blackening of the metal wire with its oxide, the oxidizing or even electro-deposition, both in the constructive form represented in which the metal wire is single and placed to come across several times the couple of upper 42, and lower 43 basins, and if the metal wires are part of a drawing installation of wires in parallel that is without spring back of the wire in the same basin.

Moreover, the direct use of tissue or braiding with only carbon fibre makes possible a most effective continuous action of pickling and/or cleaning just because of the infinitesimal distance or even contact that the carbon fibres have with the surface of the metal wire in treatment. The described constructive forms are all directed to minimize the distance between the carbon fibres and the surface of the wire in treatment.

Obviously, to the above described apparatus for electrolytic or electrochemical action on metal wire, a technician of the field, in order to satisfy specific and contingent needs, may bring numerous changes, all moreover contained within protection of the present invention as defined by the following claims. Thus even if less conveniently the filaments with high electrical conduction can be made of conducting material different from carbon fibre but with the same flexibility and resistance properties. Finally, in case of the electrolytic or electrochemical action machine, inserted in a drawing line of a plurality of wires in parallel, being the same machine able to present at least one couple of electrochemical or electrolytic treatment basins of the metal wire with at least one spring back of the multiple wires and a pair of basins (42 and 43) in said spring back with a pulley (44) between them.

Claims

1. Apparatus for electrolytic or electrochemical action on metal wire, comprising a basin (8, 65, 73) within which the metal wire (4) in treatment is placed to slide; in the basin being present as electrolyte an etching solution of the wire in treatment; an electrode that winds the wire at distance; an electrolytic action is applied between the metal wire in treatment, this wire being directly connected to a lead of an electric circuit, and the electrode placed in the etching solution to activate the electrolytic action, being connected to the other lead of the electric circuit; characterised in that the electrode (21 , 28, 31 , 33, 37, 61 , 68, 75) includes material with high electrical conduction and is placed in close contact at the surface in treatment; the electrolytic solution used is interposed between the electrode and the surface of the metal wire (4) in treatment to activate the electrolytic action, but also to constitute insulating meatus between electrode and metal wire in treatment; the proximity between the material with high conduction and the metal wire generates electrical micro discharges following to micro short circuits between the material with high conduction and the metal wire.

2. Apparatus for electrolytic or electrochemical action on metal wire, according to claim 1 , in which the electrode (21 , 31 , 33, 37, 61 , 68, 75) presents the material with high electrical conduction in the form of filaments present in the components of the electrode (31 , 33, 37, 68) or constituting the electrode itself (21 , 61 , 75) as a whole or partly when dispersed or as a covering of other flexible or rigid material.

3. Apparatus for electrolytic action on metal wire, according to claim 2, in which the electrode (21 , 31 , 33, 37, 61 , 68, 75) presents said filaments made up of wires in carbon fibre.

4. Apparatus for electrolytic action on metal wire, according to claim 3, in which the wires in carbon fibre (24) are placed free as a brush (23) near the surface of the metal wire (4) in treatment.

5. Apparatus for electrolytic action on metal wire, according to claim 3, in which the wires in carbon fibre are placed to make up a tissue or braiding (61 , 67, 75) associated to the electrode (61 , 68, 75) put in contact with the surface of the metal wire (4) in treatment.

6. Apparatus for electrolytic action on metal wire, according to claim 2, in which the filaments with high electrical conduction are made of wires in carbon fibre placed immersed in a tissue, wire or braiding (32, 34, 37) in insulating material and placed in proximity of or in contact with the surface of the metal wire (4) in treatment.

7. Apparatus for electrolytic action on metal wire, according to claim 5, in which the wires in carbon fibre of the tissue or braiding (6 ,75), making up an electrode dipped in the electrolytic solution under its level (L), cover a rigid body (59, 74) that is not put in contact with the metal wire (4) in treatment.

8. Apparatus for electrolytic action on metal wire, according to claim 7, in which the wires in carbon fibre of the braiding tissue (61 , 67, 75), making up an electrode dipped in the electrolytic solution under its level (L), cover a body in insulating material (59, 66, 74) and resistant to the mechanical sliding action in the contact with the wire (4) in treatment.

9. Apparatus for electrolytic action on metal wire, according to claim 8, in which the wires in carbon fibre of the braiding tissue (67), making up an electrode dipped in the electrolytic solution under its level (L), cover a body in flexible insulating material (66) and resistant to the sliding mechanical action in the contact with the metal wire (4) in treatment.

10. Apparatus for electrolytic action on metal wire, according to claim 6, in which the tissue or the braiding (32) is made like a small tube and the metal wire (4) in treatment is introduced and surrounded by this tube-like electrode (31).

11. Apparatus for electrolytic action on metal wire, according to claim 6, in which the tissue or the braiding is made as a wound strip (33) to form a wound small tube (34) on the metal wire in treatment and stopped by interrupted rings (35).

12. Apparatus for electrolytic action on metal wire, according to claim 1 , in which the electrode (28), made of a material however conductor of the electric current, is coated by woven insulating material (29), interposed between it and the metal wire (4) in treatment, so being able be approached to the surface in treatment of the metal wire.

13. Apparatus for electrolytic action on metal wire, according to claim 6, in which the wires in carbon fibre are immersed in a wire (37) and form the same wire, completely in carbon fibre, so as to make up an electrode in the form of wire (37), that is placed wound as a spiral on a portion of metal wire (4) in treatment, immersed in the basin (8) with the electrolytic solution suitable for the desired treatment; the wire making up the electrode (37) is released on a side of the portion from an unwinding bobbin (38) and is picked, namely wound, on the opposite side on a rewinding bobbin (39); this wire making up the electrode (37) is wound as a spiral on the metal wire (4) in treatment and is rewound by motion (S) in opposite direction to the advancing motion (A) of the metal wire (4) in treatment.

14. Machine for electrochemical or electrolytic action (41) on metal wire, according to one of the preceding claims, in which the metal wire (4) in the passage in the treatment basin (8, 42, 43, 73) is subjected to the treatment in following basins along its path; moreover the passage between a basin and the next one occurs by spring back of the same wire several times in different and parallel passage paths in at least a pair of basins in sequence.

15. Machine for electrochemical or electrolytic action (41) on metal wire, according to claim 14, in which the aforementioned basins are placed at different levels with an upper basin (42) and a lower basin (43) and at least one pulley (44) that deviates the wire/s between the two basins.