EP1136616B1 - Method and device for preforming steel wires - Google Patents

Abstract

To maintain the character of steel wires (21) as they are drawn off their supply bobbins (20) for cable twisting, and keep them free of any twist before the cable twisting point (18) at a cable twisting machine (1), force components are applied to the wire (21) in a number of successive stages according to the wire diameter to impose a defined and durable spiral shape. On stretching out a coil in an axial and radial direction, the shape and dimensions match the laying length and the radial gap between the wire in its layer from the center axis of the cable, with the wire length in a coil within its twisted layer in the finished cable structure. The force components applied to the wire (21), to give the spiral structure, are applied by simultaneous and defined draw forces with bending and friction and twisting on the wire (21) surface. The number and strength of the force components applied to the wire (21) in the successive stages, and the spatial gaps between the stages and between them and a torsion block are set according to the required expansion of the spiral coils in the wire (21). A constant and accurate draw tension on the wire (21) is maintained, as it is drawn off its bobbin, by control of the bobbin brake (25) or the bobbin drive. An INDEPENDENT CLAIM is included for a cable twisting machine assembly (1) with a torsion block in the path of the wire (21) from the supply bobbin (20) to the cable twisting point (18). It has one or more guide rollers and a suitable number of fixed and adjustable shaping pins. The wire (21) is wound around the torsion block in one or more coils and in a serpentine path between the pins, on a path with narrow axial restrictions and in contact with the pins. The draw tension on the wire (21) as it is taken from the bobbin (20) is held to 100% accuracy and constancy by control of the bobbin brake (25) or the bobbin drive system. Preferred Features: The diameter of the rollers at the torsion block is set according to the wire diameter, so that the wire (21) around the rollers is brought to the threshold of plastic distortion after elastic distortion. The number of wire coils around the torsion block rollers is set so that the wire rotation around its longitudinal axis does not travel back as far as the supply bobbin (20). The diameter (D) of the guide rollers, according to the diameter (do) of the steel wire (21), is set to meet the conditions: 50Xdo=D=70Xdo. The adjustment range for the wire structuring section (19) includes the radial gap (z) from the center of the final guide roller of the torsion block to the leading shaping pin, the gap (y2) between the final guide roller and the leading shaping pin, the diameter (d) of the pin and the gap (y1) between the shaping pins according to the diameter (do) of the steel wire (21), the length (l) of the wire (21) within the twisted cable in its layer and the laying length (s) to satisfy the conditions: D/2X2do=z=D/2do/2 5do=d=7do 0.9X1/3=y1=s/3 y2=2y1 The shaping pins are deployed exactly in succession in a line or with side offset displacements, according to the number of pins used and the force components to be applied to the wire (21). The pins are of a wear resistant material with a density of 12-15 g/cm3> and a surface roughness of 0.15=Rz1=1.5. The assembly has a number of wire structuring units (19) to process a number of steel wires (21) for the twisted cable, at a fixed structuring head (37). A number of structuring heads (37) are used to match the number of twisted wire layers in the twisted cable, arranged in succession in the wire take-off direction. Each structuring head (37) is a compact unit, with a number of axially neighboring disks rotating on a common axis and which can be locked, for the array of guide rollers and the selected number of shaping pins. The controlled bobbin brake (25) is a dancer control with a swing lever (26) and a dancer roller (27) with a coupled brake belt (28), and a suitable number of brake pads (29) with a brake lining. A brake disk (30) is keyed to the bobbin (20), with a brake surface which is chromed, ground and polished to give a surface roughness of Rz2=10. The control circuit for the bobbin drive system has a frequency converter with analog processing and a proportional integral derivative (PID) control and a bus connection. The setting unit is a three-phase induction motor followed by a gearing. The feedback is taken from the draw forces on the steel wire (21) taken from the bobbin by a measurement roller and an amplifier for the measurements.

Description

The invention relates to a method and a device for the preforming of steel wires, which run without rotation of Drahtablaufspulen a stranding and are subsequently stranded in one or more layers to a steel wire strand.

Steel wire strands are known to be produced without backlash on double-turn stranding machines of the type OUT-IN or IN-OUT.

The mode of operation of these stranding machines is essentially characterized in that the individual wires are withdrawn from discharge bobbins with constant force by means of a double-pulley take-off and correspondingly stranded together, and finally the twisted dressing produced is wound onto the take-up reel of a controlled rewinder.
This procedure, which is known per se, is relatively unproblematic to carry out in the processing of wires made of so-called "plastic materials", such as copper and aluminum, since these internal stresses arising during the stranding process can easily be compensated for by plastic deformation.
For the processing of steel wires, however, it is necessary to subject the individual wires of a pretreatment to introduce the same as far as possible in the desired position of the association and as a result to expensive post-treatments of the self-made steel strand as a result of possibly irregular layer structure and during to be able to dispense with the internal stress caused by the stranding process.

Thus, DE-A-43 37 596 proposes to deduct individual steel wires, in particular wires for the production of HT and Ultra HT cord, with constant tension of mechanically retractable delivery bobbins and due to a sliding and rolling on a conical guide roller in To twist a single stranding point in double strike to the finished wire strand in their structure. To better withstand the stresses of the stranding process, the individual wires undergo a pre-deformation prior to their entry into the stranding point by they are passed through a preform nipple or around a preform roll.

It is known that during the stripping of the individual wires from the respective supply spool and the stranding of the same, the individual wires are conveyed simultaneously both a progressive movement in the direction of the stranding point and a rotational movement about its longitudinal axis.
This circumstance is used to deform the individual wires so that they assume a permanent helical shape.
As a result of this permanent helical shape a facilitated layer structure and a reduction of the internal stresses in the single wire or in the steel wire strand is seen.

EP-A-0 231 376 discloses such a generic method and a device therefor, wherein the permanent deformation of the individual wires is effected in each case by a flat bend which realizes a plastic deformation of the steel wire on at least one support, here in the form of a guide roller , and a subsequent bend is made by means of an elongated cylindrical roller in a direction which is pivoted with respect to the original flat bend.
In essence, the flat bend is realized by one or more times wrapping the guide roller through the wire or by guiding it by a plurality of staggered guide rollers.
The subsequent bending, which also corresponds to a plastic deformation of the wire, is essentially realized by the wire is spirally guided several times around the elongated cylindrical roller.
Although it has been found in practice that the above measures ensure a permanent helical shape of the steel wire, the wire has not fully assumed the shape in which the extension of a helical coil in the axial and radial directions seen the desired lay length and the radial distance the later position to the center axis of the later stranding association and the wire length of a thread turn of the actual wire length in the later stranding within the respective position corresponds.

Furthermore, the above method including the associated device is considered to be complicated and technically complicated.

Finally, US-A-6 016 647 discloses a device for preforming steel wires, wherein the steel wires run off wire spools of a stranding device and are subsequently stranded in one or more layers into a steel wire strand. Between the wire bobbin of the respective steel wire and the stranding are seen in the wire flow direction successively a torsion consisting of one or more guide rollers, and any number preforming pins, wherein the steel wire in one or more turns led around the torsion, as well as guided serpentine between the preforming pins is.

The object of the invention is to provide a further improved method and apparatus of the generic type, with which the disadvantages of the above-described prior art, can be avoided.
In particular, it is intended to allow a defined, reproducible and consistent helical shape of the respective steel wire in order to ensure a facilitated layer structure and a reduction of the internal stresses in the individual wire or in the steel wire strand.

According to the invention the object is achieved by a method for preforming steel wires and in conjunction with the features in the preamble of claim 1 such that, while maintaining a 100% accurate and constant drain tension of the steel wire between Drahtablaufspule and Verseilpunkt a stranding, depending on the diameter " d ₀ "of the steel wire to the stranded steel wire, respectively on the surface thereof, in certain stages successively by simultaneous and defined effect of tensile force and bending, friction and torsion such a force component is applied, as a result, the steel wire a defined and permanent helical Taking shape, in which the extension of a coil in the axial and radial direction of the same seen the stroke length "s" and the radial distance of the later position to the center axis of the later stranding and the wire length of a Coil winding of the actual wire length "I" in the later stranding within the respective situation by the steel wire is first led around in one or more windings around one or more leadership roles torsion barrier, where he just just undergoes an elastic deformation at the border to the plastic, and then serpentine between any number of fixedly arranged, but adjustable Vorformstifte, in a narrowly limited in the axial direction of the steel wire extending portion of the surface of the same Vorformstifte touching, is passed.

Another measure provides that the number and size of the force components acting sequentially in stages as well as the spatial distance between them and an upstream torsion barrier depending on the desired extent of the helix of the steel wire is selected.

Furthermore, it can be regarded as being according to the invention that the 100% accurate and constant discharge tension of the steel wire is realized by regulating the reel brake of the wire dispensing reel or its reel drive.

The device for preforming of steel wires is characterized in conjunction with the features in the preamble of claim 4, characterized in that between the wire drain reel of the respective steel wire and the stranding of the stranding seen in the wire flow direction successively a torsion, consisting of one or more guide rollers, as well as any Number of fixedly arranged, but adjustable preforming pins are provided, wherein the steel wire in one or more turns around the twist lock and serpentine between the preforming pins, in a narrow axially extending in the axial direction of the steel wire extending portion of the surface of the preform pins, passed, wherein in order to obtain a 100% accurate and constant drain tension of the steel wire of each wire drain reel is associated with a controllable spool brake or a controllable spool drive system, and wherein the guide roller n the torsion barrier depending on the diameter "d ₀ " of the steel wire such a diameter "D" that the order of these Guided steel wire at the border to plastic just undergoes an elastic deformation.

Furthermore, the device is characterized in that the number of convolutions is selected around the guide rollers of the torsion lock so that the existing rotational movement of the steel wire does not run back around its longitudinal axis due to the actual stranding process in the wire feed bobbin.

genügen sollte und die Einstellmaße der Vorrichtung zur Vorformung, wie der radiale Abstand "z" von Mitte letzter Führungsrolle der Torsionssperre zur Mitte erster Vorformstift, der Abstand "y₂" der letzten Führungsrolle zum ersten Vorformstift, der Durchmesser "d" der Vorformstifte und der Abstand "y₁" zwischen den Vorformstiften in Abhängigkeit vom Durchmesser "d₀" des Stahldrahtes, der wirklichen Drahtlänge "I" des Stahldrahtes im späteren Verseilverband innerhalb der jeweiligen Lage zu wählen sind und folgenden Bedingungen genügen sollten: $$\mathrm{D}/2-2{\mathrm{d}}_0\le \mathrm{z}\le \mathrm{D}/2+{\mathrm{d}}_0/2$$

$$5{\mathrm{d}}_0\le \mathrm{d}\le 7{\mathrm{d}}_0$$

$$0,9\times \mathrm{l}/3\le {\mathrm{y}}_1\le \mathrm{s}/3$$

$${\mathrm{y}}_2\approx 2{\mathrm{y}}_1$$

Furthermore, it was found that the diameter "D" of the guide rollers of the torsion barrier depending on the diameter "d ₀ " of the steel wire of the condition $$50\times {\mathrm{d}}_0\le \mathrm{D}\le 70\times {\mathrm{d}}_0$$

and the setting dimensions of the preforming device, such as the radial distance "z" from the torsion lock center last guide roller to the center first preform pin, the distance "y ₂ " of the last guide roller to the first preform pin, the diameter "d" of the preform pins and Distance "y ₁ " between the preforming pins as a function of the diameter "d ₀ " of the steel wire, the actual wire length "I" of the steel wire in the later stranding within the respective layer are to be selected and should satisfy the following conditions: $$\mathrm{D}/2-2{\mathrm{d}}_0\le \mathrm{z}\le \mathrm{D}/2+{\mathrm{d}}_0/2$$

$$5{\mathrm{d}}_0\le \mathrm{d}\le 7{\mathrm{d}}_0$$

$$0.9\times \mathrm{l}/3\le {\mathrm{y}}_1\le \mathrm{s}/3$$

$${\mathrm{y}}_2\approx 2{\mathrm{y}}_1$$

It is also appropriate to arrange the Vorformstifte depending on their number and the force component to be applied to the steel wire exactly in series behind one another or laterally offset from one another at a certain distance.

It has proved to be advantageous if the preforming pins are made of wear-resistant material with a density of 12-15 g / cm ³ and a surface roughness 0.15 ≦ Rz ₁ ≦ 1.5.

Also, it is considered to be according to the invention if the devices for preforming a plurality of steel wires to be preformed are arranged successively on a common fixed preform head and possibly several such preform heads depending on the number of layers to be stranded in the direction of drainage of the steel wires.

In a further development of the invention, it is provided that each preform head is designed as a compact component or consists of two or more on a common axis axially successively and separated from each other rotatably arranged, but lockable discs, in turn, the guide rollers and / or a freely selectable in a suitable arrangement Number Vorformstifte have.

According to a further measure, the controllable spool brake of the respective wire spool includes a dancer control in the form of a coupled with a pivot lever dancer roller brake band, which in turn has any number of brake shoes with a friction lining made of polytetrafluoroethylene (PTFE) with wear-reducing additives, and a non-rotatably connected to the Drahtablaufspule Brake disc whose chrome-plated, ground and polished brake surface has a surface roughness Rz ₂ ≤ 10.

If a controlled coil drive favors instead of the known dancer-controlled coil brake, the control loop of this coil drive system consists of a control device in the form of an inverter with analog processing and PID controller and bus connection, an actuator in the form of a 3-phase asynchronous motor with subsequent transmission and the Return, consisting of the running steel wire and the detection of the tensile force "Fz" in the form of a measuring roller and a measuring amplifier together.

The main advantages of the invention are particularly seen in the fact that a method and an apparatus for preforming steel wires were created, due to which the steel wires according to their position in the stranding, respectively in the finished steel wire strand, a defined, reproducible and consistent helical shape can be applied can.
The claimed method and the device are also as uncomplicated and the technical effort to realize the same as low estimate.

Further details of the invention will become apparent from the following explanation of the embodiments schematically illustrated in the drawings.

Figur 1

die schematische Ansicht einer das erfindungsgemäße Verfahren durchführenden Verseileinrichtung in Form einer Doppelschlagverseilmaschine der Bauart OUT-IN zur Herstellung von Stahldrahtlitzen,

Figur 2

die schematische Ansicht der Vorrichtung zur Vorformung von Stahldrähten,

Figur 3

die Ansicht 1 nach Fig. 2,

Figur 4

die Draufsicht nach Fig. 3,

Figur 5

die schematische Ansicht einer Stahldrahtlitze,

Figur 6

das Blockschaltbild eines Spulenantriebssystems der Drahtablaufspulen,

Figur 7

die schematische Ansicht einer weiteren das erfindungsgemäße Verfahren durchführenden Verseileinrichtung, hier in Form einer Doppelschlagverseilmaschine der Bauart IN-OUT.

Show it:

FIG. 1

1 is a schematic view of a stranding device according to the invention in the form of a double-turn stranding machine of the type OUT-IN for producing steel wire strands;

FIG. 2

the schematic view of the device for preforming steel wires,

FIG. 3

the view 1 of Fig. 2,

FIG. 4

the top view of FIG. 3,

FIG. 5

the schematic view of a steel wire strand,

FIG. 6

the block diagram of a coil drive system of Drahtablaufspulen,

FIG. 7

the schematic view of another the method according to the invention performing stranding, here in the form of a double-twisting machine of the type IN-OUT.

FIG. 1 schematically shows a stranding device 1 in the form of a double-turn stranding machine of the type OUT-IN, on which steel wire strands 2 can be produced and which are used, for example, in the tire industry.
This stranding device 1 essentially comprises the drive stands 3, 4, 5 and 6 in each of which the rotating systems are mounted.
Between the drive stands 3 and 4, the delivery bobbin 7 for the core wire 8 or the core strand is mounted in a creel 9, which in turn is rotatably mounted about not shown end-side hollow pin about the central axis of the rotating system, but not rotates due to its own weight in the stranding.
The same is true for the rotating system of the drive stand 5 and 6, wherein here within a creel 10, which in turn is also mounted by means not shown Endseitiger hollow pin pendulum, the take-up reel 11 together with a double-pulley 12 and optionally a Nachformeinrichtung 13 in the form of a series of are provided in a row with mutual displacement arranged straightening rollers.

On the drive shaft 14 of the drive stator 3, a guide roller 15 for the core wire 8 and the core strand is arranged, which in turn rotates at the rotational speed n = x about the central axis of the rotating system and the core wire 8 and the core strand in a free flight curve to a the drive stand 4 arranged swirling 16 leads. The twisting device 16 rotates at a speed n ≥ 2x.

On the downstream drive stand 5, a further swirling device 17 is arranged, which in turn rotates at the same speed and in the same direction of rotation as the swirling device 16.

Between the two swirling devices 16 and 17, the stranding point 18 in the form of a stranding nipple is arranged on the drive column 5, which in turn is arranged and regulated by devices 19 for preforming it braked or controlled driven wire drain coils 20 expiring steel wires 21 for a desired layer stranding of the same, upstream.

The devices 19 for preforming consist according to Figures 2 to 4 seen in the wire flow direction successively each of a so-called Torsionssperre 22, here in the form of two successively or juxtaposed guide rollers 23a and 23b over which the steel wire 21 is guided around in one or more turns.
The number of convolutions is chosen so that an existing due to the stranding rotational movement of the steel wire 21 around its longitudinal axis can not run back into the wire feed reel 20.
Furthermore, the diameter "D" of the guide rollers 23a; 23b depending on the diameter "d ₀ " of the Stahldrates 21 chosen so that the steel wire 21 undergoes an elastic deformation just at the border to the plastic just. It should preferably satisfy the following condition: $$50\times {\mathrm{d}}_0\le \mathrm{D}\le 70\times {\mathrm{d}}_0$$

The torsion barrier 22 in the form of the guide rollers 23a and 23b is an arbitrary number of stationary arranged preforming pins 24a to 24n downstream, between which the steel wire 21 is guided serpentine.
In this case, this in a narrowly limited in the axial direction of the steel wire 21 extending portion of the surface thereof the Vorformstifte 24a to 24n and learns according to the number of Vorformstifte 24a to 24n, ie in stages, suitable force components, which in turn from a simultaneous effect of tensile force , Bending, friction and torsion on the steel wire 21, respectively on its surface, result.

$$5{\mathrm{d}}_0\le \mathrm{d}\le 7{\mathrm{d}}_0$$

$$0,9\times \mathrm{l}/3\le {\mathrm{y}}_1\le \mathrm{s}/3$$

$${\mathrm{y}}_2\approx 2{\mathrm{y}}_1$$

As a result of extensive experimentation, it has been found that the setting dimensions of the preforming device 19, such as the radial distance "z" from the center last guide roller 23b of the torsion stopper 22 to the center of the first preforming pin 24a, the distance "y ₂ " of the last guide roller 23b to the first preforming pin 24a, the diameter "d" of the preform pins 24a to 24n and the distance "y _1" between the preform pins 24a to 24n depending on the diameter "d _0" of the steel wire 21 and the actual wire length "l" of the steel wire 21 in the latter, d. H. finished stranded strand within the respective position and the lay length "s" are selected and should satisfy the following conditions: $$\mathrm{D}/2-2{\mathrm{d}}_0\le \mathrm{z}\le \mathrm{D}/2+{\mathrm{d}}_0/2$$

$$5{\mathrm{d}}_0\le \mathrm{d}\le 7{\mathrm{d}}_0$$

$$0.9\times \mathrm{l}/3\le {\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="imgf0001.png,imgf0006.png"\; state="\{\{state\}\}">y</figure-callout>}}_1\le \mathrm{s}/3$$

$${\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="imgf0001.png,imgf0006.png"\; state="\{\{state\}\}">y</figure-callout>}}_2\approx 2{\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="imgf0001.png,imgf0006.png"\; state="\{\{state\}\}">y</figure-callout>}}_1$$

Referring to Fig. 5, the actual wire length "l" of the steel wire 21, also referred to as the straight length, is determined by the condition | = √ s ² + (d _mi x π) ² , where "s" is the lay length and "d _mi "denote the mean diameter of the ith layer.

It goes without saying for the person skilled in the art that as the number of preforming pins 24a to 24n increases, the force components acting on the steel wire 21 also change.
In order to be able to influence these within limits, it is indicated if necessary, the Vorformstifte 24a to 24n, which are fixed to be arranged to perform so adjustable that this either as shown in Fig. 4 exactly in series one behind the other or at a certain distance from one another laterally can be arranged offset (not shown).

In a preferred arrangement, in practice at diameters "d ₀ " of the steel wire 21 from 0.18 to 0.22 mm, four preforming pins 24a to 24n have proven successful.

In order to be able to counteract wear of the preforming pins 24a to 24n or damage to the steel wires 21 to be stranded, the preforming pins 24a to 24n are preferably made of wear-resistant material with a density of 12-15 g / cm ³ and a surface roughness of 0.15 ≤ Rz ₁ ≤ 1.5 made.
For this purpose, preferably offer hardened steel but also ceramic materials.

As essential for the achievement of the task, a 100% accurate and constant drain tension of the steel wire 21 between the wire feed bobbin 20 and the stranding point 18 of the stranding device 1 has been found.

This can be realized such that, as shown in Fig. 1, each Drahtablaufspule 20 is provided with a regulated spool brake 25, wherein the spool brake 25 from a known dancer control in the form of a coupled to a pivot lever 26 of a dancer roller 27 brake band 28, in turn, any number of brake shoes 29 with a friction lining made of polytetrafluoroethylene (PTFE) with wear-reducing additives, such. B. 20 to 25% carbon content and / or certain glass fiber proportions, and also consists of a rotatably connected to the Drahtablaufspule 20 brake disc 30 whose chromed, ground and polished braking surface over a surface roughness Rz ₂ ≤ 10 has.

Furthermore, it is also possible to regulate the discharge voltage by means of a controllable coil drive system for each delivery reel 20. Substantially, the control loop of this coil drive system according to FIG. 6 is composed of the control device in the form of an inverter 31 with analog processing and PID controller and bus connection 32, an actuator in the form of a 3-phase asynchronous motor 33 with subsequent transmission 34 and the feedback from the outgoing steel wire 21 and the detection of the tensile force "Fz" in the form of a measuring roller 35 and a measuring amplifier 36, together.

It has proven expedient to arrange the devices 19 for preforming a plurality of steel wires 21 to be preformed on a common preforming head 37, preferably concentrically around the central axis thereof (FIGS. 1 and 2).

Likewise, it is also possible to arrange a plurality of such preform heads 37, for example, depending on the number of layers to be stranded in the direction of flow of the steel wires 21 in succession (not shown in detail).

Each preforming head 37 can furthermore be embodied as a compact component, wherein the individual preforming pins 24a to 24n are designed to be adjustable so that they can laterally be displaced relative to one another due to, for example, a plurality of threaded bores arranged on the surface of the preforming head but also of two (Fig.3 and 4) or a plurality of discs 37b axially rotatable and separated from each other on a common axis 37a, but rotatably mounted; 37c, which in turn have the guide rollers 23a and 23b of the torsion locks 22 and / or a freely selectable number of preforming pins 24a to 24n in a suitable arrangement.
The discs 37b and 37c are each frictionally locked by means of a screw 37d on the axis 37a, for example.

With the above measure, depending on the arrangement of the devices 19 for preforming on the said discs 37b; 37c, if necessary, the possibility of both the radial distance "z" from the center last guide roller 23b of the torsion 22 to the center of the first preforming pin 24a and the lateral displacement of the preforming pins 24a to 24n to each other to set limits.

The mode of operation of the invention at the stranding device 1 in the form of a double-turn stranding machine of the type OUT-IN (FIG. 1) is described below:

As already stated above, the core wire 8 or the core strand with constant tensile force is drawn off from the bobbin 7 arranged in the coil frame 9 and via the with the rotational speed n = x rotating about the central axis of the rotating system guide roller 15 in free flight curve to the Draliereinrichtung 16, which in turn rotates at twice the speed (n = 2x) of the guide roller 15 and continues to the stranding point 18.
Within the Verseilpunktes 18, the individual layers of steel wires 21 are applied, the individual steel wires 21 according to the invention with 100% accurate and constant drain voltage of controlled slowed down drain bobbins 7 withdrawn and before entering the stranding 18, the device 19 for preforming the respective steel wire 21st consisting of the torsion brake 22 and the successively arranged Vorformstiften 24a to 24n happen.

Depending on the diameter "d ₀ " of the steel wire 21, by means of successively arranged preforming pins 24a to 24n, that is, in certain stages successively such a force component applied to the respective steel wire 21, that as a result, the steel wire 21 a defined and lasting assumes a helical shape in which the extension of a helical coil in the axial and radial directions thereof seen the desired lay length "s" and the radial distance of the later position to the center axis of the later stranding, or the finished steel wire strand 2, and the wire length of a coil turn of the actual wire length "I" in the later stranding within the respective situation corresponds.

It has been found that the force component producing the helical twist of the steel wire 21 is generated by the simultaneous and defined action of tensile force and bending, friction and torsion on the steel wire 21, respectively on the surface thereof, such that the steel wire 21 is serpentine between the preforming pins 24a to 24n is guided while in a narrowly limited in the axial direction of the steel wire extending portion of the surface of the preform pins 24a to 24n touched.

The number and size of the force components acting sequentially in stages as well as the spatial distance of the same to each other and to the upstream torsion barrier 22 is selected as a function of the desired extent of the helix of the steel wire 21, that for preferred wire diameter "d ₀ " in the context of previous Try the number of preforming pins 24a to 24n and optionally the lateral offset of each other and, using the particular conditions determined, the appropriate distance "y ₂ " between the last guide roller 23b of the torsion barrier 22 and the first preforming pin 24a, the appropriate distances "y ₁ " between the individual preform pins 24a to 24n and the suitable radial distance "z" from the center of the last guide roller 23b of the torsion barrier 22 to the middle of the first preform pin 23b.

Subsequently, the permanent helically shaped steel wires 21 are stranded in the stranding point 18 in layers, with first and second stranding being realized in the common stranding point 18.
Subsequently, the steel wire strand 2, which is finished in its structure, is moved, via the second swirling device 17, which rotates at the same rotational speed as the swirling device 16, in a free flight curve to form a guide roller 38 on the Drive stand 6 arranged drive shaft 39 passed, which rotates at half the rotational speed of the twisting 16 and 17 (x = n). Finally, the steel wire strand 2 is known to be fed via the double-pulley 12 and optionally provided Nachformeinrichtungen 13, which in turn should still eliminate any residual stresses in the steel wire strand 2, which is arranged within the coil frame 10 take-up reel 11.

It goes without saying that the invention not only for double-twist stranding machines of the type OUT-IN, but also for other known stranding 1, such. B. Doppelschlagverseilmaschinen of the type IN-OUT, can be used.

7 shows a stranding device 1 in the form of a double-hemming stranding machine of the type IN-OUT, which in turn differs from the already described double-hemming stranding machine of the type OUT-IN in that the Drahtablaufspulen 20, including controlled bobbin brake 25 or alternatively controllable coil drive system and the preform head 37 are mounted with the devices arranged thereon 19 for preforming the steel wires 21 within the rotating system thereof in a coil frame 40 oscillating.

The core wire 8 or the core strand is known to be withdrawn from a arranged outside the rotating system drain spool 7 and guided over so-called concurrent flyers 41 a and 41 b in free flight curve in the central axis of the rotating system to the stranding point 18. There, the individual steel wires 21 after they have passed their device 19 for preforming layer by layer on the core wire 8 and the core strand applied, which seen in the wire flow direction behind the stranding point 18 arranged swirling device 42 with the double speed of the flyer 41 a and 41 b rotates and As a result, the steel wire strand 2 formed by the individual steel wires 21 experiences a complete stranding, the first and second stranding being combined in one stranding point 18.

Finally, the self-made steel wire strand 2 via the two flyers 41 a and 41 b from the rotating system out to the known double-disc take-off 12 and optionally via already mentioned above Nachformeinrichtungen 13 and over a turning device 43 of the take-up reel 11 fed.

Claims (13)

1. Method for preforming steel wires (21) which unreel, without backtwist, from wire pay-off reels (20) of a stranding device (1) and are subsequently stranded into one or more layers to form a steel wire heald (2), wherein, if a 100% accurate and constant pay-off tension of the steel wire (21) between the wire pay-off reel (20) and the stranding point (18) of the stranding device (1) is maintained, as a function of the diameter "d₀" of the steel wire (21) there can be applied to the steel wire (21) to be stranded, and to the surface of the same, successively in set stages by simultaneous and defined action of tensile force, as well as bending, friction and torsion, a force component such that the steel wire (21) eventually assumes a defined and permanent helical form in which the extension of a turn, viewed in the radial and axial direction of the same, corresponds to the desired length of lay "s" and to the radial distance of the subsequent layer to the centre axis of the subsequent stranding structure, and the wire length of a turn corresponds to the actual wire length "1" in the subsequent stranding structure within the respective layer, characterized in that the steel wire (21) is firstly led in one or more turns around one or more guide rollers (23a, b) of a torsion lock (22), whereupon it undergoes, at the boundary to the plastic deformation, just about an elastic deformation, and is then led through in a serpentine pattern between an optional number of fixedly disposed, yet adjustable preform pins (24a-n) in a tightly confined region of the surface of the steel wire (21) extending in the axial direction of the same, such that it touches the preform pins (24a-n).
2. Method according to Claim 1, characterized in that the number and size of the force components acting successively in stages, and the mutual spacing of the preform pins (24a-n) and the distance to the upstream torsion lock (22), are chosen as a function of the desired extension of the turn of the steel wire (21).
3. Method according to Claim 1 or 2, characterized in that the 100% accurate and constant pay-off tension of the steel wire (21) is achieved by a controlling of the reel brake (25) of the wire pay-off reel (20) or of its reel drive.
4. Device (19) for preforming steel wires (21) which unreel, without backtwist, from wire pay-off reels (20) of a stranding device (1) and are subsequently stranded into one or more layers to form a steel wire heald (2), wherein, between the wire pay-off reel (20) of the respective steel wire (21) and the stranding point (18) of the stranding device (1), there are successively provided, viewed in the wire pay-off direction, a torsion lock (22), comprising one or more guide rollers (23a, b), and an optional number of fixedly disposed, yet adjustable preform pins (24a-n), whereupon the steel wire (21) is led in one or more turns around the torsion lock (22), and is led in a serpentine pattern between the preform pins (24a-n) in a tightly confined region of the surface of the steel wire (21) extending in the axial direction of the same, such that it touches the preform pins (24a-n), wherein, in order to obtain a 100% accurate and constant pay-off tension of the steel wire (21), each wire pay-off reel (20) is assigned a controllable reel brake (25) or a controllable reel drive system, characterized in that the guide rollers (23a, b) of the torsion lock (22), as a function of the diameter "d₀" of the steel wire (21), have a diameter "D" such that the steel wire (21) led around these undergoes at the boundary to the plastic deformation, just about an elastic deformation.
5. Device (19) according to Claim 4, characterized in that the number of turns around the guide rollers (23a, b) of the torsion lock (22) is chosen such that the existing rotary motion of the steel wire (21) about its longitudinal axis does not feed back into the wire pay-off reel (21) as a result of the actual stranding operation.
6. Device (19) according to Claim 4 or 5, characterized in that the diameter "D" of the guide rollers (23a, b) of the torsion lock (22), as a function of the diameter "d₀" of the steel wire (21), satisfies the following condition: $$50\times {\mathrm{d}}_0\le \mathrm{D}\le 70\times {\mathrm{d}}_0\mathrm{.}$$

   
7. Device (19) according to one of Claims 4 to 6, characterized in that the setting dimensions of the preforming device (19), such as the radial distance "z" from the middle of the last guide roller (23b) of the torsion lock (22) to the middle of the first preform pin (24a), the distance "y2" of the last guide roller (23b) to the first preform pin (24a), the diameter "d" of the preform pins (24a-n) and the distance "y₁" between the preform pins (24a-n), are chosen as a function of the diameter "d₀" of the steel wire (21), of the actual wire length "1" of the steel wire (21) in the subsequent stranding structure within the respective layer and the length of lay "s" and satisfy the following conditions: $$\mathrm{D}/2-2{\mathrm{d}}_0\le \mathrm{z}\le \mathrm{D}/2+{\mathrm{d}}_0/2$$

   

   $$5{\mathrm{d}}_0\le \mathrm{d}\le 7{\mathrm{d}}_0$$

   

   $$0.9\times \mathrm{l}/3\le {\mathrm{y}}_1\le \mathrm{s}/3$$

   

   $${\mathrm{y}}_2\approx 2{\mathrm{y}}_1.$$

   
8. Device (19) according to one of Claims 4 to 7, characterized in that the preform pins (24a-n), as a function of their number and the force component to be applied to the steel wire (21), are disposed exactly in line one behind the other or laterally offset at a set distance apart.
9. Device (19) according to one of Claims 4 to 8, characterized in that the preform pins (24a-n) consist of wear-resistant material having a density of 12-15 g/cm³ and a surface roughness 0.15 ≤ Rz₁ ≤ 1.5.
10. Device (19) according to one of Claims 4 to 9, characterized in that the devices (19) for preforming a plurality of steel wires (21) to be preformed are successively disposed, viewed in the pay-off direction of the steel wires (21), on a common, fixedly disposed preform head (37) and, where applicable, a plurality of such preform heads (37), as a function of the number of layers to be stranded.
11. Device (19) according to Claim 10, characterized in that each preform head (37) is constructed as a compact component or comprises two or more plates (37b; 37c), which are rotatably disposed on a common axis (37a) in axial succession and separate from one another, yet are lockable, and which, for their part, have the guide rollers (23a, b) and/or a freely selectable number of preform pins (24a-n) in suitable arrangement.
12. Device (19) according to one of Claims 4 to 11, characterized in that the controllable reel brake (25) of the respective wire pay-off reel (20) comprises a dancer control system in the form of a brake band (28) coupled to a pivoted lever (26) of a dancer roll (27), which brake band, for its part, has an optional number of brake shoes (29) with a friction lining made of polytetrafluoroethylene (PTFE) containing wear-reducing additives, and a brake disc (30), which is connected in a rotationally secure manner to the wire pay-off reel (20) and the chrome-plated, ground and polished brake surface of which boasts a surface roughness Rz₂ ≤ 10.
13. Device (19) according to one of Claims 4 to 12, characterized in that the control circuit of the reel drive system is composed of a control device in the form of a converter (31) with analogue processing and PID controller and bus port (32), a servo element in the form of a 3-phase asynchronous motor (33) with following gear mechanism (34) and the feedback circuit, comprising the unreeling steel wire (21) and the registration of the tensile force "Fz" in the form of a measuring roller (35) and a measurement amplifier (36).

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