EP0396068B1 - Method and apparatus for making a bundle of wires or a cable - Google Patents

Abstract

The invention relates to a method and an apparatus for making a bundle of a plurality of individual metal wires (strands) or a cable composed of a plurality of strands. To obtain strands of substantially improved quality, it is proposed to give the strand a low constant tensile stress during production, continuously to measure the torsion value of the strand or cable in the region of this low constant tensile stress during the entire production operation, and, in the event of deviations of the measured torsion value from the predetermined torsion value, to generate a control signal, by means of which the rotational speed of the overwinding device is varied in such a way that the strand or cable assumes the set torsion value again.

Description

The invention relates to a method for producing a bundle from a plurality of metallic individual wires (strand) or a rope from a plurality of strands, in which the wires or strands are pulled off in a conventional manner by means of a pull-out device via a rotor from braked coils of a coil carrier and with an adjustable lay length are laid around one another and / or twisted around one another, in which the stranded wires or stranded strands are then further twisted in their twisting direction in an overturning device, so that the residual torsion of the strand or the rope fluctuates by an adjustable constant value, and at the end the finished strand or rope is wound up on a spool or is processed immediately. The invention further relates to a device for producing a bundle of several metallic individual wires (strand) or a rope made of several strands, with a coil carrier with braked coils for receiving individual wires or strands with a rotor for folding and / or twisting the wires or Stranded wire, with an overturning device, with at least one pull-out mechanism and with a winding or transfer device (see, for example, JP-A-56-9489).

A strand is understood to mean a bundle of at least two, but usually several, for example four or five individual wires, which are laid around and / or twisted around one another. A rope is understood to mean a bundle of several strands or of more than eight individual wires or of a combination of strands and individual wires, which in turn are laid around and / or twisted around one another. Under one Lay length is to be understood as the distance between two points of a wire or a strand with the same spatial position after a complete twist by 360 ^o . The unit of measurement 1 torsion is to be defined in the context of this application in such a way that a 6 m long piece of strand unwound from a spool after the end has been released is rotated 360 ^o in the direction of rotation (+ 1 torsion) or in the opposite direction (- 1st Torsion).

When producing a strand on known stranding machines, the individual wires, e.g. high-strength, surface-treated steel wires can be drawn off from coils by means of a pull-out mechanism and twisted around one another with an adjustable lay length by means of a rotor to form a strand. Because of the spring properties of the wires, a torque that opposes this torsion occurs. In order to produce a strand with a certain torsion value, e.g. To obtain the value zero, the strand is twisted even further in its direction of rotation by means of an overturning device, as a rule beyond the elastic deformation range into the plastic one.

The reaction of such an "overturned" strand is a reverse rotation which fluctuates around zero, ie the strand will normally show no or only a weak reaction in or against the direction of rotation. One then speaks of plus or minus residual torsions. In a metal cord made from the strands, these residual torsions represent an important feature of the cord, since the flatness of a rubberized metal cord sheet mainly depends on the residual torsions. Furthermore, the residual torsions are responsible for the uniformity of the cut edges of the cord sections, which are required, for example, in tire construction to produce the individual layers. In case of different or strong residual torsions have a ripple effect in the cutting edge.

In known bunching machines, the residual torsions can only be measured when the machine is switched off and the strand is cut open. If the measured value is within the permissible limits, the machine is put into operation again; if the value is inadmissible, the speed of the overturning device is usually increased or decreased via a mechanical adjustment gear in order to obtain the desired value. These measurements are repeated after passing through predetermined strand lengths.

In the known manufacturing processes, there are not inconsiderable residual torsional fluctuations over the strand or rope lengths, which primarily result from the surface properties of the individual wires differing over the wire length and the structure of the steel wire itself, to a lesser extent from influences of the bunching machine. The known manufacturing processes therefore have the disadvantage that products of poor quality or even to a considerable extent result in rejects and that the bunching machines cannot be operated optimally because of the frequent stopping and restarting.

The invention is therefore based on the object of specifying a method for producing a strand or a rope of substantially improved quality, in which, in particular, the problems indicated no longer occur due to different residual torsions.

This object is achieved in that the strand or the rope behind the overturning device or the puller is given a low constant tension that in the range of low constant tension during the entire manufacturing process Torsion value of the strand or the rope is measured continuously and that if the torsion measurement deviates from the set torsion value, a control signal is generated by means of which the speed of the over-twisting device is changed in such a way that the strand or the rope again assumes the set torsion value.

A device for producing a strand or a rope is characterized in that a tension generator stage for maintaining a low constant tension is located between the pull-out unit and the winding or transfer device, and in the area of the low constant tension a torsion measuring device for the continuous detection of the torsion value is present, the measurement signal of which can be fed to a control device, the output signal of which changes the speed of the overturning device.

The main idea of the invention is to continuously measure the torsion value of the strand or the rope during the entire production process and to correct it immediately in the event of deviations from the set value. The measurement is carried out in a measuring loop with a torsion measuring roller, which changes its angular position in the event of deviations from the target value and thereby generates a correction signal. In order to be able to detect even slight deviations from the residual torsion setpoint with the torsion measuring device, it is proposed according to the invention to give the strand a low constant tensile stress in a certain area and to arrange the measuring device in this area of the strand guide. The control signal of the torsion measuring roller is used to change the speed of the overturning device via an electrical circuit in such a way that the strand or the rope again assumes the set torsion value (setpoint).

Above all, the invention offers the advantage that for the first time it has been possible to produce a strand of great length which, regardless of the length-changing properties of the individual wires, maintains a predetermined residual torsion value over its entire length. This avoids rejects both in the strand material and in the cord material subsequently produced therefrom. The advantage of the stranding or stranding machine is that the elimination of a mechanical winding coupling and a mechanical adjusting mechanism of the overturning device eliminates approximately 95% of the wear parts of the machine, which results in a considerable reduction in indirect personnel. Finally, a further advantage is a reduction in testing costs and rework.

The invention is explained in more detail below using the example of a bunching machine in the form of a double striking machine.

It shows the only figure
a beating machine (partially schematic) in a side view.

The bunching machine essentially consists of the main assemblies bobbin 1, rotor 2, overturning device 3, pull-out mechanism 4, take-up device 5 and the assemblies according to the invention tension generator 6, torsion measuring device 7, control device 8 and conventional drive units.

In the coil carrier 1 there are two coils 1.2 on each of two fixed axes 1.1, on which wires 1.3, for example brass-plated steel wires, are wound, from which a strand is to be produced. In the case of strands for tire cords, the individual wires 1.3 can have a diameter of approximately 0.25 mm. To slow down the Coils 1.2 serve brakes 1.4. The wires 1.3 are guided when pulling over collecting rollers 1.5 and rollers 1.6 forming a fixed point and an output roller 1.7.

The rotor 2, which is driven by the motor 9 via belts 10 and an intermediate shaft 11, consists essentially of two rotor disks 2.1, which are wrapped several times by the individual wires 1.3. Two deflection rollers 2.2 are used to guide the individual wires 1.3 that have already been brought together to form a strand 12.

After leaving the rotor 2, the heald 12 is fed to the overturning device 3, which essentially consists of two rollers 3.2, arranged side by side in a bracket 3.1, around which the heald 12 is guided, and a drive unit 3.3. The drive unit 3.3 can be designed in such a way that the overturning device 3 is driven by the main motor 9 via drive belt 10, the intermediate shaft 11 and a gear 4.3 and that an additional motor in the unit 3.3 is only used to change the speed. However, a separate drive motor can also be provided. In any case, synchronization means should be provided for a synchronous start of the roto 2 and the overturning device 3. By changing the speed of the overturning device 3, the degree of overturning of the strand 12 and thus its residual torsion value can be set.

Downstream of the overturning device 3 is a pull-out mechanism 4, which in the present example essentially consists of two pull-out rollers 4.1 and 4.2, of which the pull-out roller 4.2 is motor-driven, specifically via a reduction gear 4.3, which is connected to the intermediate shaft 11. The strand 12 is generally wrapped around the rollers 4.1 and 4.2 at least ten times. Can in certain applications two pull-out units are also used, of which the second is then usually located between the rotor 2 and the overturning device 3.

At the end of the bunching machine, the finished strand 12 is wound in the winding device 5 onto a driven spool 5.1. A laying device 5.2 ensures the correct winding of the strand 12 in the usual way. If required, the finished strand 12 can be fed to an immediate further processing instead of to the winding device 5 via a deflection roller (not shown). If necessary, the bunching machine can also have a customary post-forming device.

The subassemblies of the bunching machine that are essential to the invention are described below, namely the tension generator stage 6, the torsion measuring device 7 and the control device 8.

After leaving the pull-out unit 4, the strand 12 is fed to the tension generator stage 6 via a deflection roller 13, which in the present example consists of a dancer device with two rollers 6.1 and 6.2. The roller 6.2 is arranged in a fixed position, while the dancer roller 6.1 is located on a dancer arm 6.3 which can be pivoted about an axis A and which carries a weight 6.4 on its rear side via a linkage. The weight 6.4 determines the position of the dancer arm 6.3. The strand 12 is guided around the rollers 6.1 and 6.2 about four times. On the back of the dancer arm 6.3 there is also a signal transmitter (potentiometer) 6.5, the signal of which is fed in the control device 8 to a control circuit with the controller R1, which controls the winding device 5 in such a way that a constant position results for the movable dancer arm 6.3, which results in a constant tension for the strand 12. In the case of a strand of four or five individual wires for one Tire cord, this tension should be less than 15 Newtons.

After leaving the tension generator stage 6, the strand 12 is fed to a first deflecting roller 7.1 of the torsion measuring device 7 and runs from there, forming a measuring loop 7.2 around a torsion measuring roller 7.3, back to a second deflecting roller 7.4 and finally to the winding device 5. The upper edges of the rollers 7.1 and 7.4 are approximately at the level of the axis of the torsion roller 7.3. The torsion measuring roller 7.3, the diameter of which can be between 8 and 20 cm, is mounted in a roller arm 7.5, which is easily rotatable about its longitudinal axis.

An electronic signal transmitter 7.6 is connected to the torsion measuring roller 7.3 and generates an electrical signal depending on the angle of rotation of the roller arm 7.5 and thus the torsion measuring roller 7.3. This signal is fed in the control device 8 - possibly with the interposition of an integrator stage 8.1 - to a comparison stage 8.2. In comparison stage 8.2, the signal is compared with a signal which can be set on controller R2 and which corresponds to the desired value of the residual torsion. In response to the comparison, an output signal is generated in comparison stage 8.2 and sent to the drive unit 3.3 of the overturning device, which changes the speed of the overturning device 3 in such a way that the strand 12 again assumes the value set on the controller R2.

The operation of the stranding machine and the method for producing a strand are to be explained in more detail below. After starting the The beating machine sets the rotor 2, the puller 4, the overturning device 3 and the winding device 5 in motion, whereby a synchronous start is ensured. After start-up, the strand 12 moves at a speed of approximately 100 to 200 m / min, and the striking discs 2.1 of the rotor 2 rotate at a speed of approximately 5 to 6000 rpm. The four individual wires 1.3 are withdrawn from the braked coils 1.2 and rotated around one another with the aid of the striking discs 2.1, where they receive their first lay on the right deflection pulley 2.2 and their second lay on the left deflection pulley 2.2, so that here the final lay length of the strand 12 is reached. The amount of the lay length is determined by the pull-off speed of the pull-out unit 4 and the speed of the striking discs 2.1.

High-strength steel wires, which are used in the manufacture of strands for a tire cord as individual wires 1.3, react when twisted due to their spring properties to the twist with a reverse torque against the twisting direction. This return torque of the strand 12 is canceled or set to a desired final value (residual torsion) in that the strand 12 is further twisted together in the overturning device 3, specifically via the elastic deformation region into the plastic one.

After passing through the pulling unit 4, the strand 12 is guided via the tension generator stage 6 and the torsion measuring device 7 to the winding device 5 and is wound there on a spool 5.1. While high pulling forces act on the strand 12 up to the pull-out mechanism 4, the tension generator stage 6 ensures that the strand 12 is guided over the measuring loop of the torsion measuring device 7 with an extremely low constant tension. Only this constant low Tension allows a sensitive torsion measurement on the strand 12. The amount of tension can be adjusted with the regulator R1. If the tensile stress begins to deviate from this value due to external influences, the dancer arm 6.3 changes its position by slightly pivoting about the axis A, as a result of which a correction signal is generated in the signal generator 6.5, which changes the winding speed of the winding spool 5.1 via the control device 8, so that the exact tension value is immediately restored.

In the torsion measuring device 7, the strand 12 is continuously guided as a measuring loop 7.2, in which the torsion measuring roller 7.3 hangs. In the example described, a value of approximately 1 m has proven to be favorable for the length of the measuring loop. It is important that the ends of the measuring loop 7.2 are guided as close as possible to one another. The torsion measuring device 7 functions as follows. First, the desired residual torsion value of the strand 12 is set with the regulator R2, which can be zero, but can also be a specific value of a plus torsion or minus torsion. As long as there are no torsional fluctuations in the measuring loop 7.2, the electrical circuit of the control device 8 supplies a signal to the drive unit 3.3, which has the effect that the overturning device 3 has exactly such a speed that it gives the strand 12 the desired residual torsion value. As long as the strand 12 maintains this value, the position of the torsion measuring roller 7.3 does not change. As soon as, for example, due to a changed surface quality of the individual wires 1.3, the residual torsion of the strand 12 in the measuring loop 7.2 deviates from the predetermined value, this results in the measuring roller 7.3 and thus the roller arm 7.5 being rotated, as a result of which a measuring signal is generated in the electronic signal transmitter 7.6 Comparator stage 8.2 is fed into the control device 8 and there is a changed one Output signal generated. With this output signal, the speed of the overturning device 3 is changed in such a way that the desired residual torsion value, which is set on the regulator R2, is immediately obtained again on the strand 12. As soon as the disturbance stops due to the changed surface of the individual wires, a control mechanism starts in the opposite direction. The detection of torsional fluctuations with the torsion measuring roller 7.3 is so sensitive that it may be expedient to first feed the signals generated in the electronic transmitter 7.6 to an integrator stage 8.1 and to initiate the readjustment mechanism after a certain threshold has been reached.

It should be noted that the invention can also be carried out with a single impact machine instead of the double impact machine described. Above all, instead of the strands described, the invention can also be used to produce ropes with a residual torsion that is constant over their length. In this case, there are not individual wires but strands in the coils 1.2 of the coil carrier.

List of reference numbers

1

Coil carrier

1.1

stationary axes

1.2

Do the washing up

1.3

Wires

1.4

Band brake

1.5

Collecting roles

1.6

roll

1.7

Initial role

2nd

rotor

2.1

Impact discs

2.2

Pulleys

3rd

Overturning device

3.1

hanger

3.2

roll

3.3

Drive unit

4th

Pull-out mechanism

4.1

Pull-out roll

4.2

motorized pull-out roller

5

Take-up device

5.1

Kitchen sink

5.2

Laying device

6

Tension generator stage

6.1

Dancer role

6.2

stationary role

6.3

Dancer arm

6.4

Weight

6.5

Signal generator

7

Torsion measuring device

7.1

first pulley

7.2

Measuring loop

7.3

Torsion roller

7.4

second pulley

7.5

Roller arm

7.6

electronic signal generator

8th

Control device

8.1

Integrator level

8.2

Comparison level

9

engine

10th

belt

11

Intermediate shaft

12th

Strand

13

Pulley

A

axis

R1

Controller 1

R2

Controller 2

Claims (13)

1. Method of producing a bundle comprising a plurality of metallic individual wires (strand) or a cable comprising a plurality of strands, wherein the wires or strands are unwound from braked coils of a coil carrier in conventional manner by means of an extractor via a rotor and are laid around one another and/or twisted around one another with an adjustable length of lay and/or twist, wherein the stranded wires or cabled strands respectively are subsequently wound together further in an overwinding means in their twisting direction, so that the residual torsion of the strand or cable, respectively, varies by an adjustable constant value, and wherein the finished strand or the finished cable is wound onto a coil at the end or is subsequently directly treated, characterised in that the strand or the cable respectively is given a low constant tensile stress behind the overwinding means or the extractor, respectively, in that the torsional value of the strand or respectively of the cable is constantly measured in the region of the low constant tensile stress during the entire production process, and in that, in the event of the torsion measurement value deviating from the set torsional value, a control signal is produced, by means of which the speed of the overwinding means is changed in such a manner that the strand or cable respectively resumes the set torsional value.
2. Method according to claim 1, characterised in that the signal for the torsion measurement value is compared in a comparison stage with a signal which corresponds to the set torsional value, and in that, in the event of deviations, an output signal is produced and transmitted to the drive of the overwinding means, such signal changing the speed of said overwinding means.
3. Method according to claim 2, characterised in that the signal for the torsion measurement value is initially supplied to an integrator stage.
4. Method according to claim 1, characterised in that the torsion of the strand or cable respectively is measured in a measuring loop which has a length of approximately 1 m.
5. Method according to claim 1, characterised in that the low constant tensile stress is produced by a compensating means.
6. Method according to claim 1, characterised in that the maximum tensile stress of the strand or cable respectively behind the overwinding means is 15 newtons.
7. Apparatus for producing a bundle comprising a plurality of metallic individual wires (strand) or a cable comprising a plurality of strands, including a coil carrier having braked coils for receiving individual wires or strands, respectively, a rotor for laying and/or twisting the wires or strands around one another, an overwinding means, at least one extractor and one winding-on or advancing device, characterized in that a tensile stress producing stage (6), for keeping to a low constant tensile stress, is situated between the extractor (4) and the winding-on (5) or advancing device, and in that a torsion-measuring means (7), for constantly determining the torsional value, is provided in the region of the low constant tensile stress, the measuring signal of said torsion-measuring means being feedable to a regulating means (8), the output signal of which changes the speed of the overwinding means (3).
8. Apparatus according to claim 7, characterized in that the torsion-measuring means (7) has a torsion-measuring roller (7.3), which is mounted in a roller arm (7.5) rotatable about its longitudinal axis, and has a signal transmitter (7.6).
9. Apparatus according to claim 8, characterized in that the diameter of the torsion-measuring roller (7.3) is between 8 and 20 cm.
10. Apparatus according to claim 7, characterized in that the tensile stress producing stage (6) comprises a compensating means which has a stationary roller (6.2) and a roller (6.1), which is mounted in a compensating arm (6.3) pivotable about an axis (A).
11. Apparatus according to claim 7, characterized by a comparison stage (8.2) in the regulating means (8), the measuring signal of the signal transmitter (7.6) being feedable to one input of said regulating means, and a signal for a torsional value, which signal is adjustable with a regulator (R2), is feedable to the other input of said regulating means, and the output signal of said regulating means can be applied to one input of the drive assembly (3.3) of the overwinding means (3).
12. Bundle comprising a plurality of individual wires (strand), or cable comprising a plurality of strands, produced according to the method of claim 1, characterized in that the strand (12) or the cable respectively has a constant residual torsional value over its entire length.
13. Strand or cable according to claim 12, characterized in that it is processed in a cord web.

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