EP1388379A1 - Device for drawing or stretching (wires, bars, tubes) with a quasi zero wear of the die and the reaching of optimal tribological conditions - Google Patents

Abstract

The device uses a threaded tube (1) screwed into a threaded sleeve (2) which itself is held in a large section square (3) welded to the side plates of the slide or soap box. The device uses a threaded tube (1) screwed into a threaded sleeve (2) which itself is held in a large section square (3) welded to the side plates of the slide or soap box. A range of tubes of different internal diameters and substantial thickness are made with a hardness in the range 58HRC (Rockwell C hardness) to 3500HV (Vickers hardness) and have a conical part which matches exactly the angle of the drawing frame. The two surfaces in contact are mirror polished to a roughness of Ra=5/100[deg] of micron. The carbides of the working drawing frame are compacted micrograins using the best HIP (High isostatic pressure) processes. Alternatively, the drawing frame is made of industrial nitride, carbide or boride ceramics with a very high hardness, greater than 1200HV (Vickers), or combined industrial diamond structures of very high hardness and compactness, greater than 1500HV (Vickers). The extruding or drawing lubricants are high viscosity greases or oils (between 20 and 15000 centistokes), with or without the following additives: graphite, molybdenum bisulphide, metal powder or alloys, polymer powder or liquid, or stearate, palmitate, calcium oleate, or sodium doped or otherwise with high pressure elements. The threaded or unthreaded tubes are cylindrical or conical with an angle of 0 to 12[deg] and of any length. The entrance of the tube is equipped with a very hard ring acting as a guide and laminator for the lubricant to engage the very high pressures. In particular for wet drawing, liquid lubricants are used with a non-return valve in the drawing frame.

Description

The present invention relates to a device for drawing or to stretch ferrous or non-ferrous metals as wire, bar, tube or non-cylindrical profile by applying very high pressures in front of the working cone of the wire drawing process (7) of FIG. 2, thus creating an anti-wear film, thanks to selected lubricants. In the current state of the art, Metal drawing and drawing, conditions tribological are such that the factories are faced with anticipated wear and tear on the supply chains, therefore budgets important, to anticipated wear of the Metallization, capstans, to excessive consumption of wire drawing soap, to creation of surface defects on the wires with all their unfortunate consequences for the final product. in addition lead the manufacturer to reduce by 30 to 50% the speed of machines, this, by force of circumstances, with the loss of consecutive productivity.

The device according to the invention makes it possible to remedy, quantitatively and qualitatively to all these disadvantages inherent in the Trades supra.

• la figure 1 représente en vue de dessus un dispositif de l'invention. La figure 2 représente en coupe une zone précise de ce dispositif.La figure 3 représente les trois pièces mécaniques de ce dispositif, soit 1,2,3 (en vue de dessus).
• La figure 4 représente la pièce (4) en coupe.
• La figure 5 un tube (16) non fileté.
• La figure 6 représente un montage spécifiquement adapté au Tréfilage VOIE HUMIDE, oü les lubrifiants sont liquides et de faible Viscosité.
• La figure 7 représente un montage simplifié par rapport à celui de la fig 1 et s'applique plus particulièrement aux petites et moyennes filières cylindriques (ou non).

The accompanying drawings illustrate the invention:

• Figure 1 shows a top view of a device of the invention. Figure 2 shows in section a specific area of this device. Figure 3 shows the three mechanical parts of this device, or 1,2,3 (in top view).
• Figure 4 shows the part (4) in section.
• Figure 5 a tube (16) not threaded.
• FIG. 6 represents an assembly specifically adapted to WET DRAWING, where the lubricants are liquid and of low viscosity.
• Figure 7 shows a simplified assembly compared to that of Fig 1 and applies more particularly to small and medium cylindrical (or not).

For figure 1: There are 2 kinds of tubes (1) and (16) page 2/3 and 3/3: -the threaded tubes, which are an integral part of the device according to the invention and the non-threaded tubes.

Threaded or not, there are 3 dimensional models of tubes for be able to cover the whole range of wire diameters to be drawn.

In figure 1, the part (3) is a square of 60X60m / m of steel (XC48) welded on the flanges of the casting machine after a meticulous alignment. The tube (1) of great thickness and high hardness, is terminated by a mirror-polished cone (8) which fits perfectly into the mirror-polished cone made of Tungsten carbide or other material of the die (11). The tightening under high pressure is done by the threaded sleeve of (2) which is fitted with a hexagon nut (10); a flat (9) allows the tube to be held during its plating in the cone of the die. In FIG. 1: the 2 surfaces (8) have undergone a mirror-polish type glazing, ie a Ra (roughness) = 5/100 of a micron. The cylindrical dies (11), according to the European ISO model, are housed in a very thick metal ring (12), which itself is introduced into the die holder (13). The lubricant, greases or oils of high viscosity or lubricant powder, flows into (5) by means of a translucent funnel adjusted to the diameter of the hole. The ring (14) allows to receive a die / guide with a diameter greater than 20 / 100 m / m to that of the diameter of the wire (18). The wire, with its speed and its roughness causes lubricant "extreme pressure" in the cramped corridor (6) to (4) and thus plays the role a real compressor piston. The pressures in 7, FIG. 2, are very high, greater than 5000 bars depending on the lubricant chosen, and when the values of the air gap (6) and the length of the tube (1) are optimized; the table on page 5 gives values without limitation. Zone 4 benefits from a lamellar flow, of the hydrodynamic type which has the consequence of bending the metal before the point of impact on the carbide track or other material .

Therefore, the "drawing ring" on the tungsten carbide cone or other disappears and with it, the anticipated deterioration of the die, the "drawing ring" is a halo on the cone (8) of tungsten carbide due to the impact of metal arriving at high speed, generally soiled on its skin with metal particles of an earlier origin, and also due to the strong pressures to which the carbide track is subjected (8). This phenomenon anticipates death of the sector; it has always been known in the trade, but real solutions have not been provided; the device according to the invention acts on this precise point, and visceral for the wire drawing.

The device according to the invention thus makes it possible to do away with the “Retapage” operation, which is expensive and tedious for the manufacturer. The film (15) of high compactness and of lamellar structure, repeated several times will play a real anti-wear role; it constitutes the first device objective according to the invention so that the drawing machines can rotate at the speeds provided by the Manufacturers.

• des graisses au graphite,ou au bisulfure de molybdène,ou avec des poudres métalliques, ou avec des ajouts d'alliages métalliques ,ou avec des polymères type anti-friction ou autres: Téflon,etc .... ).
• des graisses sans les additifs précités;à titre non limitatif, les Extrême-pression et autres. Ces 2 types de graisses coulantes auront une viscosité élevée,à titre non limitatif,de 200 à 15000 Centistokes, en visant la fourchette 800 à 3000 Centistokes à l'ambiante ( 20° environ) préférenciellement, ou encore,des savons nous,coulants,de viscosité également 200 à 15000Cst chargés en corps gras connus pour leurs propriétés extrême-pression et à utiliser quand les produits finis nécessitent un lavage à l'eau;cité à titre d'exemple non limitatif.Les filières seront en carbure de Tungstène de type"micro-grains",réalisées selon le procédé HIP(haute pression isostatique), fabriquées par les grands carburiers actuels.A titre ion limitatif,les filières utilisées avec le dispositif selon l'invention pourront être constituées par des céramiques industrielles de très haute dureté,par exemple:les cermets.,les nitrures de Silicium ,les nitrures de Bore,carbures de Bore,les Diamants tous type etc ....

By way of nonlimiting example, the internal conicity of the 2 types of tubes (1) and (16) will further increase the "compacting" pressures of the lubricant film chosen, in particular in (7) Figure 2. page 6 gives the characteristics of the threaded tubes. Page 5 gives the characteristics of the unthreaded tubes, also called floating tubes. On multi-passes having 6 to 12 passes or more, the device according to the invention is used on 50% of the first passes; on the other 50% of the machine, the manufacturer may use floating tubes (not threaded). He himself will decide their number on the multipass. According to a variant of FIG. 3, the angle (17) will be from 0 ° (cylindrical tube) to 12, knowing that the recommended angle of the device according to the invention is The device according to the invention describes a series of threaded tubes (1) which are given on page 6; Page 5 gives the range of non-threaded (floating) tubes. Page 7 gives the mounting instructions for the tubes according to the diameters to be drawn with the 2 formulas (a) and (b) for calculating the increment inside diameter (Φi)) of the tubes. Pages 5 and 6 give: a range of Rockwell C Hardness (HRC) from 58 to 64 for a shade 100C6 as an indication. The hardness scale can range from 58 HRC (Rockwell C hardness) to 3500 HV (Vickers hardness) in passing through metallic carbides or industrial ceramics, very thick tubes to resist bursting. Lubricants will, depending on the type of product to be hardened:

• greases with graphite, or with molybdenum disulphide, or with metallic powders, or with additions of metallic alloys, or with anti-friction type polymers or others: Teflon, etc.).
• greases without the aforementioned additives; non-limiting, Extreme-pressure and others. These 2 types of flowing fats will have a high viscosity, without limitation, from 200 to 15,000 Centistokes, targeting the range 800 to 3000 Centistokes at room temperature (approximately 20 °), or even soaps, soaps, also of viscosity 200 to 15000Cst loaded with fatty substances known for their extreme-pressure properties and to be used when the finished products require washing with water; cited as a non-limiting example. The dies will be made of Tungsten carbide type "micro-grains", produced according to the HIP process (high isostatic pressure), manufactured by current large carburetors. By way of limitation, the dies used with the device according to the invention may be constituted by industrial ceramics of very high hardness , for example: cermets., silicon nitrides, boron nitrides, boron carbides, diamonds of all types, etc.

The device according to the invention is particularly intended to create a zone (7) in FIG. 2 of very high pressures on a lubricant extreme pressure, of lamellar structure with strong anisotropy, non-limiting title, thus creating a hydrodynamic regime remarkable.In these optimal conditions, the tube (1) acts as pre-die by "preparing" the final work of the die / grader. Figure 7 shows a more simplified variant of the Device according to the invention of Figure 1:

A ring (12) made of non-ferrous or ferrous metal has 2 threaded holes (25), diametrically opposite, each receiving a screw (24) which presses the tube (1) by resting on a notch (9) which has been made in this tube; the tube (1) is conical according to the same criteria mentioned above on the preceding pages; it can be terminated, on the die side, either by a mirror-polished cone, according to the criteria defined above, or by a polished flat part which is applied vigorously against the die (11); at the entrance to this tube, a housing is provided, during its design, to receive a welded, brazed or other core (14) of tungsten carbide or other material; this core will play the role of : guide die and laminating lubricant die to use the principle of FIG. 6, already explained. The screws, two or more in number, are, without limitation, hardened steel of hardness 42/60 HRC having a fine thread for power resistant to high clamping pressures, plating the tube (1) against the die ( 11). The thick frusto-conical ring (12) will, as an indication, be made of high-strength bronze or hardened steel of hardness 48/60 HRC to save the duration of the threading. When the work hardening is important e> 25%, the ring (12) can receive 2, (see 3) dies (11) and (23) thus allowing to optimize the reduction of section in a single operation. to work, a preliminary Curve of Wire Drawing Constraints is to be established; (Purpose: to know the relationship between the required Wire Drawing Effort and the resistance of the wire, to avoid its Breakage during the manufacturing phase).
the ring (12) equipped with its tube 1, its die (s) 11 + 23, its screws 24 is threaded into its die holder 13, generally cooled with water, by the water-jacket system. the criteria / Material and dimensions on: the tube (1), the support ring 12, the screws 24, the die (s) 11 + 23 are given without limitation; the tables on pages 5,6,7,8 nevertheless give elements leading directly to an optimization of the Implementation of Metals and other materials.

The device according to the invention with its 2 variants, inexpensive, can easily be adapted to all kinds of casting machines, benches and multipasses.
the device according to the invention is particularly intended for creating a film of residual lubricant, highly compacted, intended to perfect the tribological conditions during the shaping by the customers whose permanent concern is: the wear of their tools. According to a second variant of the invention, in the case of Wet Wire Drawing, all metals combined, the device will be mounted in a "enclosing" tube represented by FIG. 4: the die 11, the non-threaded tube 16, the die 14 are all closed in a tube 19 of great thickness threaded at one end supporting a nut 20 of large caliber; the die 14 has a core / wire gap of 0 to a few hundredths of m / m, with a value of 5 to 10 1 / 100 'of m / m, as an indication; taking into account the film of lubricant which is "rolled" on the wire to increase its wettability, the velocities of the kinetic energies of the lubricant "crushed" on the wire by the roller clamp 21 being located just upstream from the "rolling machine""; the device according to the invention creates a lubricant anti-return system; note that the quantity of this which passes through the air gap is 3 to 4 times greater than the quantity of the wire / flier interface film; this film undergoes a high degree of compacification thanks to the triple congested phenomenon of: exiguity of the air gap of the die (14), of the corridor effect of the tube of unlimited length and spacer and of the phenomenon of "corner" of the conical corridor with an angle 17 of 1.7 ° given to non-limiting title. The two copper seals 22 seal the assembly.

In the case of H-wire Drawing, and especially for very heavy metals hard (more than 2000 MPa), the materials of the dies will be of a hardness greater than 1500 HV by targeting 3500/4000 HV as an indication and not limiting; the polishing of the working cone will be 5/100 of Ra approximately and the working angle, commonly called 2α will be 6 to 25 ° with an indicative value of 8 °. Liquid lubricants or pasty will preferably consist of molecules of large size, strong anisotropy, which have good resistance to strong Shear stresses and mechanical "aging" and thermal: either polymers, long chain copolymers, soaps soluble doped or not, waxes, paraffins, silicones, given without limitation. To increase the compressibility of the lubricant, it must be free of micro air bubbles in its mass, by quoting by way of nonlimiting example, the Oils of power transmission, without limitation. The conjugation optimized from the above-mentioned Criteria makes it possible to have in (7) very high pressures, to bend the metal in 4, and, therefore, obtaining of a hydrodynamic regime with lamellar facies, as a result of the good aforementioned lubricant, and the considerable minimization of the "point impact "of metal arriving at high speed; these conditions met remove the presence of the "Wire Drawing Ring" that exists even on very hard materials, diamonds, in others; in Consequently, the dies "wear out", but without being damaged; Intern in the Supply Chain Workshop finally becomes possible and with consequence for the Producer of the metal involved, the removal of the expensive and tedious "Retapage" operation; Multipasses, only the "Finished" sectors are new; others in the machine body come from the RITA system: Bearing Internal on the Heap, of the sectors mentioned above.

Page 7 gives, without limitation, a range of diameters inside the tubes which can be either cylindrical or preferably conical with an angle of 1.5 ° given as indicative, of unlimited length.

Due to its Tribological Objectives of the implementation of Metals in the form of Long Products, by drawing or drawing operation, the device according to the invention with its 2 main targets: Dry Way and Wet Way , all products and all shades combined, is really intended to honor the fundamental objectives of the aforementioned profession, namely: the productivity of the machines by applying the speeds designed by the Manufacturer, the reduction in the "Sector Budget", the Quality of the surface condition of the work hardened products, the Longevity of metallization of capstans and control of the costs of drawing lubricants.

WET TRACK

• Gamme de fils tréfilés
  

• angle (α) : angle intérieur du tube (cônique).
  Nota: Dans la phase de Pré-Qualification du dispositif selon l'invention,il est recommandé,à titre de comparaison,de commencer avec des tubes à intérieur cylindriques (angle =O).
• Nuance des tubes/manchon : Inox austénitiques (anti-corrosion).
  
  
  

Either, submerged or semi-emerged machine or by bubbling. Liquid or pasty / greasy soaps. Table of tube dimensions for 2 types of Cylindrical Diamond Dies: 42 X 30 and 28 X 16. (diameter and thickness). in m / m. given by way of example and not limiting.

• Range of drawn wires
  

• angle (α): internal angle of the tube (conical).
  Note: In the Pre-Qualification phase of the device according to the invention, it is recommended, for comparison, to start with tubes with cylindrical interior (angle = O).
• Grade of tubes / sleeve: Austenitic stainless steel (anti-corrosion).
  
  
  

Claims (10)

Device for drawing or drawing ferrous and non-ferrous metals in the form of wire, bar, tube or non-cylindrical profile in that it is characterized by a threaded tube (1) screwed into a threaded sleeve (2) which itself is engaged in a square of large section (3) welded to the flanges of the casting machine or soap box. Device according to claim 1 characterized in that the range of tubes provided on page 6 are very thick, of hardness ranging from 58 HRC (Rockwell C hardness) to 3500 HV (Vickers hardness) and the conical part of which perfectly matches the angle of the die, and whose 2 contact surfaces have undergone a "mirror polish", ie a roughness of: Ra = 5/100 ° of micron. Device according to claim 2 characterized in that the carbides of the working dies are micro-grains compacted according to the best HIP (High Isostatic Pressure) processes. Device according to claim 2 characterized in that the dies are constituted by industrial ceramics of the Nitrides, carbides or Borides type of very high hardness, greater than 1200 HV (Vickers hardness); or industrial diamonds, all structures combined, very high hardness and compactness, greater than 1500 HV (Vickers hardness). Device according to one of the preceding claims, characterized in that the Drawing / Drawing Lubricants are greases or oils of high viscosity ranging from 20 to 15,000 Centistokes, with or without the following additives, without limitation: graphite, molybdenum disulphide , metallic powders or alloys, powdered or liquid / waxy polymers or, powders of the type: stearate, palmitate, calcium or sodium oleate doped or not with Extreme-Pressure elements, given without limitation. Device according to any one of the preceding claims, characterized in that the threaded (1) or non-threaded (16) tubes of length not determined but given for information, are cylindrical or conical with an angle ranging from 0 to 12 °. Device according to any one of claims characterized in that , in the case of assembly of FIG. 7, the tube 1 is equipped at the entrance with a very hard core playing the role of guide and laminator of lubricant for engaging the phenomenon of very high pressures. Device according to any one of the claims, characterized in that , in the case of drawing in the wet way more particularly, the assembly represented by FIG. 6 will be more suitable for liquid lubricants, taking into account the "non-return valve" effect. of the die 14 whose air gap Die / die will be from 0 to a few hundredths of m / m for the passage of the lubricant. Device according to any one of the preceding claims, characterized in that , for the Wet Way in particular, the lubricants chosen will be of the type: with macro-molecules doped or not with extreme-pressure elements and the combination of which is suitable for lubricants The chosen ones will be of the type: with doped or non-doped macro-molecules, a non-tearable wire / die interface film will be created due to its high compacification and the great anisotropy of the elements involved; by way of indication, the copolymers with a "ball" structure and of high molar mass added with teflon micro-powders, ie PTFE, will preferably be chosen, without limitation. Device according to any one of the preceding claims, characterized in that the Producer will fix himself, on the Benches and the Multipasses, one or other of the variants of the device according to the invention, either the model of Figures 1 or 5 or 6 depending on the Specifications and the metal involved.

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