FR2790462A1 - Internally unwinding welding wire coil is wound around central axis with axially close wound turns divided into radial layers of turns - Google Patents

Abstract

The invention relates to a coil of metal wire comprising a metal wire wound around a central axis, in turns substantially contiguous axially to each other, the turns being distributed in several radial layers of turns, the radial layers of turns being superimposed. radially to each other. The coil has a central cavity and the unwinding end of the metal wire is formed by the end of the wire connected to the turns constituting the layer of turns located radially towards said central cavity of the coil. can be used in a welding operation, in particular an electric arc welding operation.

Description

The invention relates to a coil of metal wire, in particular wire

  welding fuse, with central cavity and unwinding from the inside, as well as its

manufacturing process.

  It is customary to condition the metallic wires, in particular the fusible welding wires, in the form

  spools of thread or in the form of drums.

  Usually, the coils of wires are obtained by winding the wire on the central core, generally of cylindrical shape, comprising two lateral cheeks fixed to the ends of this central core; the central core and the side cheeks being conventionally made of material

plastic or metal.

  Most often, the winding is done by winding with contiguous turns, metal wire on the central core, the turns being distributed in several layers

superimposed on each other.

  Such spools of wire usually weigh

about 15 kg.

  During the unwinding, the extraction of the unwound wire, that is to say the use of the wire in a welding operation for example, is done by pulling the wire by a motorized unwinding system, which generates a setting rotation of the coil around its central axis to

unwind the thread.

  In other words, more precisely, the motorized unwinding system exerts a tensile force on the unwinding end of the thread, that is to say on the end of the thread situated outside the spool, this

which generates the unwinding of the wire.

  In this case, the turns located towards the outside of the coil are unwound first since these turns were wound after the turns located further

  inside, i.e. the center of the coil.

  However, this type of winding requires putting the reel in rotation around its central axis in order to be able to unwind the said wire, which has the drawback of making it compulsory to use a reel-holder, on which must be positioned the reel before its unwinding, and requires - therefore manipulations by the operator of the reel before its unwinding. The wire feeder support must have braking means to prevent the turns from moving away from each other when the wire feed stops

(inertia of the coil).

  Furthermore, if one wishes to unwind this type of coil without spinning, it is then necessary to

  unwind by side pull.

  However, unwinding by lateral traction of this type of coil presents a major problem, namely that of leading to the formation of the phenomenon of "knots", resulting from a twist of the wire.

thus unfolded.

  Indeed, when you unwind by lateral traction the turns of a spool of any wire, the latter undergoes, during the unwinding, a twist of one turn per

  spiral wound leading to the formation of "knots".

  In order to try to solve the aforementioned problems and drawbacks, a particular type of packaging for metal wires has been developed,

  know the packaging in barrels or barrels.

  To do this, during its packaging, the metal wire is routed through a square tube animated by a rotational movement, while being introduced

inside the barrel.

  This rotational movement of the square tube generates a counter-twist in the wire which tends to oppose the harmful twist caused during unwinding. In addition, in order to ensure correct distribution of the wire over the entire height of the barrel, it is necessary to give the barrel both a rotational movement and a

  translation from top to bottom, and vice versa.

  This winding process overcomes the problem of forming "knots" by making it possible to

  unwinding of the wire from the inside of the spool, i.e.

  say that, in this case, the turns wound first are unwound first, unlike unwinding

  coils with contiguous turns mentioned above.

  However, this process is not entirely satisfactory because it is limited to the manufacture of coils packaged in drums, therefore of coils of a weight in general, of the order of 300 kg, and cannot be easily adapted to the coils. smaller dimensions,

  for example to coils of the order of 15 kg.

  In addition, this winding process does not allow

  wind the coils with contiguous turns.

  Finally, the packaging of the metal wire in barrels has the drawback of increasing the handling problems, in particular the handling and storage at the site of use of the wire. Indeed, it is easily understood that a barrel of welding wire of 300 kg cannot be easily transported for the welding operation directly to the place where the welding must be carried out, for example on a construction site, and therefore requires the operator either to pre-cut the length of wire necessary for welding, or to recondition the wire on a small coil of wire more easily transportable, for example a coil of 15 Kg but, in this case, the aforementioned problems reappear ,

  notably the phenomenon of "knots" when unwinding.

  The present invention therefore aims to solve the problems and drawbacks raised by proposing a coil of metal wire: - with contiguous turns, - making it possible to unwind the wire without the appearance of the phenomenon of "knots", - of any dimensions, in particular of reduced dimensions compatible with easy handling by an operator, - whose unwinding does not require the use of a reel stand and does not require the spool to rotate, - which can be unwound directly inside the protective or conditioning packaging in which it is delivered, - which avoids all the drawbacks linked to the inertia of the coil (brake, force in the transient phases of acceleration, etc.), and - which eventually allows to provide the packaging containing the coil with new functions as explained below. The present invention therefore relates to a coil of metal wire comprising a metal wire wound around a central axis (AA) according to turns substantially contiguous axially to each other, the turns being distributed in several radial layers of turns, at least part said radial layers of turns being at least partially superimposed radially with one another, characterized in that the unwinding end of said metal wire consists of the end of the wire connected to the turns constituting the layer of turns located radially inward from the coil, i.e. to the central cavity of the coil. In other words, the unwinding end is the end of the wire wound first when winding the wire. Consequently, by operating a lateral pull on this unwinding end, the operator obtains an unwinding of the radial layers of turns of the coil, starting with those located towards the inside of the coil, that is to say layers of the most turns

  central, opposite the central cavity.

  As explained below, this type of coil with contiguous turns and unwinding from the inside carries a wire

  metallic rolled up being subjected to a counter force

  twist between 0.5 turn and 1.20 turn per wound coil, preferably about one turn per wound coil. In this way, during the unwinding of the wire, the counter twist force applied to the wire will oppose the twisting force which generates the phenomenon of "knots" and the wire can then unwind substantially

straight and knot-free.

  Preferably, the metal wire has an elastic limit (Rs) such that: (G. dext5) / (Db. (Dext - dint4)) <Rs

4 4 4 _

  with (dext4 / (dext - dint4)) = 1 for a solid wire, and o: - G is the transverse elastic modulus of the wire, - dext is the outside diameter of the wire, - Db is the diameter of the coil of wire,

  - dint is the inside diameter of the wire.

  In fact, when winding the wire, it should be constrained by about one turn on itself for each coil turn, but without this

  stress does not exceed the elastic limit of the wire.

  From there, if we compare the wire to a spring working in torsion (cf. "Technical formula of general mechanics", J. Muller, 16th edition, page 242, figure 252) then we obtain ,: PR = (7. G. dext4) / (16.Db) o - PR is the torque of the wire,

  - G, dext and Db being given above.

  From there, for a solid wire, one obtains, after simplification (cf. "Technical formula of general mechanics"): (G.dext) / Db <Rs (I) Clearly, it is advisable, so that the solid wire does not does not deform plastically, whether its elastic limit (Rs) is greater than or equal, preferably greater, than its modulus of transverse elasticity multiplied by the

  quotient of the wire diameter over the winding diameter.

  However, for a tubular wire (non-solid wire), of the cored welding wire type, it is necessary to take into account the moment of inertia which is in the ratio of (1 / d3) to

  (dext / (dext4 - dint4)), o dext and dint are given above.

  From there, formula (I) above becomes: (G. dext5) / (Db. (Dext4 - dint4)) <Rs (II) In summary, whatever the type of wire, formula (II) is verified because dint = 0 and, for a solid wire, we then have: (dext4 / (dext4 - dint4)) = 1 Thus, we have made coils of wire according to the invention, with solid steel wires having a elastic limit Rs of 40 kg.mm-2 and 60 kg.mm-2, an outside diameter (dext) equal to 1.2 mm and a diameter of

300 mm Db winding.

  The coil according to the invention can, moreover, comprise one or more of the following characteristics: - the unwound end of the wire is substantially straight and without "without knot"; - the metal wire is a welding wire, preferably a solid welding wire, - the wire has a wire length (LF) of at least 500 m, preferably at least 1 km, and / or has a wire diameter (DF) of between 0.7 mm and 1.7 mm, - it comprises from 50 to 300 turns per axial layer and / or from 2 to 100 radial layers of turns per coil, preferably from 10 to 50 radial layers, - it does not have a central core or means

winding support.

  The invention also relates to a packaging, preferably of cardboard or plastic material, shrinking the outer turns, containing a coil of metal wire according to the invention, said packaging further comprising at least one orifice for passage of the end of

unwinding of the metal wire.

  Furthermore, the invention also relates to an installation for manufacturing a spool of wire according to the invention, it comprises: - means for supplying a metal wire coming from a source of metal wire, - means of torsion enabling a controlled counter-torsion force of between 0.5 and 1.20 turns to be applied to the metal wire per wound coil, preferably approximately 1 turn per coil, - means for driving the wire, - metal wire straightening means arranged downstream of the twisting means, - winding means comprising at least one winding mandrel, at least one mandrel being capable of being rotated about its axis

central by rotary means.

  Depending on the case, the installation may include one or more of the following characteristics: - torsion means comprise at least one torsion pin; - The wire straightening means comprise at least one wire straightener making it possible to straighten the wire and participating in the counter-twisting of said wire; - the winding mandrel is retractable; - It also includes conditioning means allowing the coil to be inserted into

a means of packaging.

  In addition, the invention relates to a method of manufacturing a coil of wire according to the invention, it comprises at least the following steps: (a) a metal wire is brought in from a metal wire source, (b) a controlled counter-twisting force of between 0.5 turn and 1.20 turn per wound coil is applied to the wire to the wire, preferably equivalent to approximately one turn per wire wound, and (c) the wire is wound to contiguous turns and in several layers of turns at least

  partially superimposed on a winding mandrel.

  Preferably, steps (a) to (c) are carried out

substantially continuously.

  Advantageously, the metal wire is straightened between

steps (b) and (c).

  Preferably, the winding speed is at least 5 m.s-1, preferably from 15 m.s-1 to 30 m.s1 The invention will now be described in more detail using the attached figures given as

illustrative but not limiting.

  Figure 1 shows a schematic view of a coil manufacturing installation 1 according to the invention. More specifically, a metal wire F originating from a source 2 of metal wire, such as a supply coil, is subjected to a counter-torsional force in torsion means 3, such as a torsion pin, so as to impart to the wire a counter-torsion force equivalent to

  approximately 1 turn per coiled coil.

  The twist of the wire is obtained thanks to the

  wire F which is linked in rotation to the torsion pin.

  The wire is rotated by the pull of the take-up reel 1 comprising a retractable mandrel 6 with an axis (AA), the wire F being guided by conveyor means 5, such as drive rollers or the like. In this case , the speed WA of rotation of the winding axis (AA) and the speed WB of rotation of the axis of

  the torsion pin 3 are such that: WA = 2.WB.

  It should be noted that the supply coil 2 is preferably linked in rotation to the torsion pin 3 and rotates at speed WB, so as not to subject the wire F to torsion upstream of the pin 3

of torsion.

  In addition, after passing through the torsion drive system comprising the wire straightening means 4 and the conveying means 5, the wire F is wound on the retractable mandrel 6, which allows, after winding, to have access to the internal turns of the coil 1 which can then be unwound the

  first thus avoiding the appearance of "knots".

  The wire F therefore undergoes, between the wire straightening means and the winding mandrel 6, a controlled counter-twist equivalent to approximately one revolution per

coil wound on coil 1.

  The previous system applies particularly well to coils of small dimensions, that is to say from 5 to 25 kg, but can also be used to produce coils of larger size, for example coils of 100 to 300 kg. In addition, this system makes it possible to manufacture coils with contiguous turns which makes it possible to reduce the size of the packaging, that is to say of the protective packaging,

of each coil thus produced.

  Figure 2 is a diagram of an installation according to the invention similar to that of Figure 1, which can be used to make coils according

  the invention, for example coils of 300 kg.

  As detailed in FIG. 2, the supplying reel 2 is carried by a reel support 12, which support 12 is driven by a rotational movement of WC speed, while the supplying reel 2 is driven by a rotating movement around of its axis (DD) of

WD speed.

  The wire F animated with a rotary movement of speed of rotation WB passes successively through the torsion spindle 3 then through the rectifier system 4 and 5, before being wound, that is to say wound, on the mandrel of

retractable winding 6.

  The winding mandrel 6 is, for its part, driven by a rotary movement of speed WA around its axis.

(A.A).

  As an indication, we choose WA, WB and WC such

that: WA = 2 WB and WC = WB.

  The mandrel 6 is, in this case, carried by a winding carriage 7 which is movable in translation and is provided with a foldable bearing 9 to allow the introduction of the coil 1, after complete winding, inside of

  its packaging 8, for example a cardboard packaging.

  In practice, when the winding of the reel 1 is completed, the bearing 9 folds down, so as to allow

  to bring the packaging 8 author of the reel 1.

  Then, the mandrel 6 can be retracted and the assembly constituted by the packaging 8 and the coil 1 can then

be evacuated.

  The winding installation according to the invention makes it possible to manufacture coils of all dimensions with contiguous turns and unwinding from the inside without appearance

  of the phenomenon of "knots" and without inertia.

  In fact, the winding of the wire F on the retractable mandrel 6 is done by starting from the inside of the coil and ending with the turns located the outermost, that is to say at the periphery of the reel 1, while the unwinding of reel 1 is done

  also from the inside of the coil.

  FIGS. 3 to 5 represent, respectively, a coil B of welding wire F according to the prior art (Fig. 3) and according to the present invention (Fig. 4 and 5),

  shown schematically during unwinding.

  In Figure 3, we see that, according to the prior art, the unwinding of the reel is done by lateral traction of the wire carried by the reel B, which is usually placed on a reel support not shown, the turns S located at outside of the coil B taking place first, which leads to the untimely formation of loops or "knots" N on the wire F unwound by lateral traction. Conversely, as shown in Figures 4 and, the unwinding of a coil B of wire according to the invention does not require a reel support and is done statically, since the coil B is not

rotation.

  Indeed, the coil B according to the invention takes place from the inside, that is to say through its central cavity CC; the turns S which unwind first are those located most inward of the coil B, which

  has neither central core nor side cheeks.

  The wire F having been subjected to a counter-twist of about one turn per wound coil, during its winding, it takes place while remaining substantially

  straight and without causing a loop or knot.

  This also allows the coil B to be left in its packaging C, in the wall of which is an orifice 0 for passage of the wire F. As can be seen in FIG. 5, which is a diagram in longitudinal section of a part of the coil of FIG. 4, the wire F which unwinds first and which therefore constitutes the unwinding end comes from the unwinding of the layer of turns SP1 situated opposite

  the central cavity CC of the coil B of central axis (A'-

  AT'). In other words, the unwinding is done from the inside of the coil B, the layer of turns SP1 unwinding before the layer of turns SP2, which

  takes place before the layer of turns SP3 ....

  The coils 1 of wire produced according to the invention have numerous advantages, namely in particular:

  - they can be unwound statically, that is

  that is to say without having to be placed on a reel support and it is therefore no longer necessary to provide a coil brake whose adjustment is often a problem; - the reeling force exerted by the operator is constant whatever the diameter of the reel, in particular the phenomenon of inertia at the start and end of reeling no longer exists; - thanks to the counter-twist applied to the wire during its winding, the unwinding of said wire immediately leads to a substantially straight wire without loop or knot; the absence of an expanding loop improves operator safety and reduces the risk of injury; - The implementation of the reels is facilitated because they can remain in their wrapping or packaging, since it is no longer necessary to place them on reel supports. All the information relating to the wire can therefore be read at any time, for example through an opening or a window fitted on the packaging. This allows the operator

to avoid any wire confusion.

  - they can exist in various dimensions and sizes; - they remain protected by their packaging during their use and it is therefore possible, even desirable, in certain applications to subject the interior of the packaging to a flow of welding gas or to scanning by means of an inert gas or not; - the packaging can be provided with coding means, such as a printed circuit establishing contact between several tips to identify wire parameters, in particular the diameter or nature of the wire contained in the packaging, or to automatically call a given display or welding program by means of a link between said packaging and a welding current generator; and - they can be easily fitted with an electrical contact device to detect the end of the coil. The invention also relates to the use of a coil of wire according to the invention, possibly contained in a package, in a welding operation, in particular an electric arc welding operation, in particular in MAG (Metal Active) welding. Gas) or arc

submerged.

Claims (10)

Claims   1. Coil of metal wire comprising a metal wire wound around a central axis, according to turns substantially contiguous axially to each other, the turns being distributed in several radial layers of turns, at least part of said radial layers of turns being at least partially superimposed radially to each other, characterized in that said coil has a central cavity and in that the unwinding end of said metal wire consists of the end of the wire connected to the turns constituting the layer of turns located radially towards   said central cavity of the coil.   2. Coil according to claim 1, characterized in that the wound metal wire is subjected to a counter-twisting force of between 0.5 turn and 1.2 turn per wound coil, preferably equal to or equivalent to approximately 1 turn per wound coil.   3. Coil according to one of claims 1 or 2,   characterized in that the metal wire has an elastic limit (Rs) such that: Rs 2 (G. dext5) / (Db. (dext4 - dint4)) with (dext4 / (dext4 dint4)) = 1 for a solid wire, and o: - G is the transverse elastic modulus of the wire, - dext is the outside diameter of the wire, - Db is the diameter of the coil of wire,   - dint is the inside diameter of the wire.   4. Coil according to one of claims 1 to 3,   characterized in that the unwound end of the wire is   substantially straight and without "without knot".   5. Coil according to one of claims 1 to 4,   characterized in that the metal wire is a welding wire, solid or tubular, in that the wire has a wire length (LF) of at least 500 m, and / or has a   wire diameter (DF) between 0.7 mm and 1.7 mm.   6. Coil according to one of claims 1 to 5,   characterized in that it comprises from 50 to 30 turns per axial layer and / or from 2 to 100 radial layers of turns per coil.   7. Packaging, preferably cardboard or plastic, containing a coil of metal wire according to   one of claims 1 to 6, said packaging   further comprising at least one orifice for passage of the unwinding end of the metal wire 8. Installation for manufacturing a spool of wire   according to one of claims 1 to 6, characterized in that   that it comprises: - means for supplying a metal wire coming from a source of metal wire, - torsion means making it possible to apply to the metal wire a controlled counter-torsion force of between 0.5 turn and 1.2 turn by turn, preferably approximately one turn per turn, - wire drawing means, wire straightening means arranged downstream of the twisting means, - winding means comprising a winding mandrel, at least said mandrel being capable of being rotated about its central axis by rotary means. 9. Installation according to claim 8, characterized in that the torsion means comprise at least one torsion pin and / or in that the wire straightening means comprise at least one wire straightener and / or in that the mandrel coil is retractable and / or in that it further comprises conditioning means allowing the insertion of the coil in a means of packaging.   10. Method of manufacturing a spool of wire according to   one of claims 1 to 6, characterized in that it   comprises at least the following steps, preferably carried out substantially continuously: (a) a metal wire is brought in from a metal wire source, (b) a controlled counter twist force of between 0.5 turns is applied to the metal wire 1.2 turn per turn, preferably equivalent to approximately one turn per wound turn, and (c) a winding is operated around a central axis of the metal wire with axially contiguous turns and in at least several radial layers of turns   partially superimposed on a winding mandrel.