EP3163586B1 - Twisting device for electrical lines - Google Patents

Description

The invention relates to a twisting device for electrical lines, according to the preamble of claim 1, and a method therefor, according to the preamble of claim 13.

In the WO2013068990A1 For example, there is disclosed a method for twisting electrical or optical lines, such as wires, cables, bundles of lines, optical fibers, etc., in a twisting device having two counter-rotating twisting heads. The wires are successively drawn into the twisting device between the twisting heads, and during the twisting operation, the pitch of the twisting heads is reduced from each other, preferably in response to the turns of the twisting heads, to compensate for the total length shortening of the twisted wires during twisting. Advantageous variants provide for gradually increasing the rotational speed of the twisting heads during a first portion of the twisting operation and for successively reducing them during a second portion of the twisting operation or for separately increasing and reducing the rotational speeds of the twisting heads or for programmable rotational speed profiles.

In such methods, significant disturbances are the length fluctuation of the individual lines, tolerances due to cable changes in the machine, temperature fluctuations and tolerances of the cable outer diameter. The quality of the twist also depends on the force applied when twisting in the cable axis. Applying a constant force to the wires during twisting according to the shortening profile is very demanding in an automated process. An arithmetical (theoretical) determination of the shortening profile must be individually adjusted for each twist to eliminate the disturbance variables.

This applies equally to a device as in the EP1032095B1 discloses where a regulation of the shortening profile is provided. The cable is clamped on both sides, on a fixed gripper a force sensor is attached. A twisting rotor is movably installed and moves the shortening of the line as synchronously as possible to the actual line shortening, whereby its position is controlled taking into account the measured force. The tensile force is determined at the fixed terminal and derived derived from the feed path of the Verdrillmotors. This solution requires very fast signal processing. However, in the control process, the force fluctuates around a preset value, whereby due to the extremely dynamic process, it is only possible to respond with a delay, so that it is difficult to control an error. Maintaining an exact traction is almost impossible, which can also lead to a high percentage of rejects here. This applies in particular to short lines to be twisted, which have little damping effect axially; It is an extremely high standard effort required.

Another group of machines, the so-called semi-automatic line twisters, work in the area of line shortening against a permanent force, which is typically applied pneumatically. A quality control would be because of the long ways of shortening to realize only at considerable expense. The topic has little priority in manual processing because the operator sees every line in the production and can thus detect errors relatively well.

Similar problems as explained above also occur during stranding. For example, the DE19631770A1 a stranding machine in which prepared lines are manually clamped. The stranding of the two lines takes place by rotating the two lines starting from the cable ends clamped in the twisting head with simultaneous controlled movement of a drillship so that the distance between the drillship and the twisting head increases as the process progresses. In this process, the pipe sections that are located between the drillship and the twisting head are twisted. In the DE19631770A1 is also described that the Verdrillspannaufnahmen are arranged movable by means of a feed device, such as a pneumatic cylinder with back pressure control, along the linear guides. This feed device with pneumatic cylinder and counter pressure control, mounted under the twisting head with the Verdrillspannaufnahmen moves the entire shortening path that arises during twisting.

The object of the present invention was therefore to design a twisting device such that the very dynamic and difficult to control due to disturbances such as material tolerances twisting process is easy to monitor that a process automation is possible with the same constant traction, with load peaks on the Lines can be avoided, and that a possibility for immediate quality control of the twisted lines is created. Another object of the invention was a method for producing twisted lines with the advantages mentioned.

The object is solved by the features of independent claim 1 and independent claim 13. Advantageous developments are set forth in the figures and in the dependent claims.

The starting point is a device having at least one twisting head which can be rotated by a motor about a rotation axis and a clamping device for the ends of the lines opposite the twisting head, wherein the twisting head can be moved towards the clamping device in the direction of its axis of rotation. For example, the chuck may have a fixed, i. be non-rotating line clamp. The motor mobility of the twisting head can be accomplished by any drive, such as electric motors, fluid motors on pneumatic or hydraulic basis, etc.

To solve the problem, such a device is characterized in that the twisting head is seated on a first, automatically motor-driven length compensating slide, wherein the clamping device is mounted on a Wegausgleichsschlitten to a length compensating slide substantially parallel to the axis of rotation of the twisting head, via a force-generating element with a Acting essentially parallel to the axis of rotation force can be acted upon.

Preferably, it is provided that a further twisting head is seated on the path compensating slide as a clamping device, which is rotatable in opposite directions about an axis of rotation common to the first twisting head.

According to a preferred embodiment of the invention, the path compensating slide is passively movable and is acted upon by a biasing element with a force away from the first twisting head. In this way, a tensile force is applied to the lines over the entire travel range of the elements moved during the twisting process, thereby improving the twisting process and its quality.

Preferably, the biasing force of the biasing element is adjustable at least before the start of the activation of the drive of the length compensation slide and preferably remains constant during the twisting process. This way you can talk about the entire traversing range a constant tensile force when twisting be applied. Material-related tolerances are compensated during the twisting by the axially movable clamping device according to the constant tensile force adapts their axial holding position.

In a simple and easily controlled design, the biasing element is connected via a controllable pressure control valve to a pressure source fluid cylinder, preferably a pneumatic cylinder according to an advantageous embodiment.

Another optional feature according to the present invention resides in that the piston rod of the fluid cylinder or the path compensation slide is provided or coupled with a distance measuring sensor which is connected to an evaluation device for determining and evaluating the travel profile of the force compensation slide. For example, the position of the piston rod or the carriage can be monitored, which corresponds to the holding position of the clamping device. Due to the small axial movements of the clamping device during the twisting process, which are typically in the range of 40mm, so that the twisting process within the "normal" tolerances is well monitored. Faults and faults outside of this normal twisting process will cause the monitoring tolerance tube to leave. This quality control of the twisting process can be realized. Instead of Wegmesssensors also initiators are conceivable, which are damped as long as the carriage is moved in the allowable monitoring tolerance hose.

Instead of a biasing element, which is acted upon to compensate for different axial paths during the Verdrillvorganges with a constant biasing force, according to another inventive embodiment of the force balance slide with a force measuring sensor and a motor drive can be equipped as a force-generating element. In this case, the power compensation slide is acted upon in dependence on the signals of the force measuring sensor by the drive at least during the twisting operation with a direction away from the first twisting head and possibly variable force.

For the quality control of the twisting operation, the driving profile of the clamping device can also be used in this case - but now actively prescribable. For this purpose, according to the invention, the drive or a control device of the force compensation slide connected to the drive with an evaluation device for determining and evaluating the driving profile of the force balance slide.

According to a further embodiment of the invention, it is provided that a drive for the length compensating slide can be activated via a programmable controller in order to drive off a travel profile predetermined for each line, line type and / or twisting parameter predominantly in the direction of the clamping device, and the maximum possible travel path the Wegausgleichsschlittens by preferably adjustable stops is kept smaller than the maximum travel of the length compensation slide. Due to the twisting process, the length of the twisted wire is shortened depending on the twisting rotations after a parabolic function. Variables in the twisting process are e.g. Line diameter, line material, line length, number of twist rotations (forward and then backward for decompression), traction during twisting and twisting length, which is to be achieved as Verdrillergebnis. The length reduction in the twisting process is thus mathematically describable according to the aforementioned variables and can be stored as a file (so-called recipe). The basic data for these formulations are initially determined in preliminary tests for each line cross-section. Once basic data has been determined, the data for other line lengths can be derived mathematically. Theoretically, the axial tensile force in the pair of wires to be twisted would remain substantially constant according to the recipe, unless this was prevented by disturbances such as material tolerances. The compensation of these tolerances by a constant holding force on the jig, however, is possible by a much smaller axial displacement than the twist itself requires.

In order to enable the largely automated implementation and monitoring of the twisting process, preferably at least the drive of the length compensating slide is connected to a control unit in which for each combination of lines and Verdrillparametern a driving profile for controlling the drive of the length compensation slide is stored.

Advantageously, it is provided that in the control unit, a sequence is implemented, which interrogates the evaluation and / or the Wegmesssensor and depending on the determined driving profile of Wegausgleichsschlittens generates a quality statement and / or adapted the driving profile of the length compensation slide, possibly as stored new driving profile for this combination of lines and Verdrillparametern in the control unit, and / or aborts the twisting operation with an error message.

The monitoring of the twisting process can also be used to automatically adjust the parameters of the twisting process. For this purpose, a device is particularly advantageous which is characterized in that a sequence is implemented in the control unit, which controls the length compensation slide such that the values supplied by the Wegmesssensor lie in a predetermined range, and generates a quality statement depending on the determined driving profile of Wegausgleichsschlittens and / or the driving profile of the length compensating carriage adapted, possibly deposited as a new driving profile for this combination of lines and Verdrillparametern in the control unit, and / or the Verdrillvorgang aborts with an error message.

• Ablängen einer ersten Leitung und Übergabe an einen aktiv verfahrbaren Verdrillkopf und eine gegenüberliegende verschiebbare Einspannvorrichtung,
• Spannen der Leitung zwischen Verdrillkopf und Einspannvorrichtung durch Verfahren zumindest des Verdrillkopfes weg von der Einspannvorrichtung,
• Aktivieren des Verdrillkopfes zur Drehung um eine parallel zu den eingespannten Leitungen liegende Drehachse, unter gleichzeitigem Verfahren des Verdrillkopfes in Richtung der Einspannvorrichtung gemäss einem vorgegebenen Fahrprofil.

To solve the problem set above, a method for twisting electrical lines can be adapted. The basic steps of such a process include the steps:

• Cutting to length of a first line and transfer to an actively movable twisting head and an opposing displaceable clamping device,
• Tensioning the line between the twisting head and the clamping device by moving at least the twisting head away from the clamping device,
• Activation of the twisting head for rotation about an axis of rotation parallel to the clamped lines, with simultaneous movement of the twisting head in the direction of the clamping device according to a predetermined driving profile.

• Beaufschlagung zumindest der Einspannvorrichtung mit einer vom Verdrillkopf weg gerichteten Kraft, allenfalls unterschiedlicher Stärke, zumindest während des Verdrillvorganges, und
• Ermittlung und Auswertung eines Fahr- oder Kraftprofils für die verschiebbare Einspannvorrichtung.

Such a method according to the invention is characterized by the following steps:

• Actuation of at least the clamping device with a direction away from the twisting force, possibly different strength, at least during the twisting process, and
• Determination and evaluation of a driving or force profile for the displaceable clamping device.

• motorisch angetriebenes Verschieben des Verdrillkopfes weg von der Einspannvorrichtung nach Einspannen der Leitung und vor Beginn des eigentlichen Verdrillvorganges, solange bis die Einspannvorrichtung um einen vordefinierten Verfahrweg verschoben ist oder eine vordefinierte Kraft anliegt,
• Messung oder zumindest mittelbare Bestimmung eines für die Länge der Leitung charakteristischen Wertes aus der dann eingenommenen Position des Verdrillkopfes,
• Wiederholung der obigen Schritte mit einer zweiten oder jeder weiteren, zusammen mit der ersten Leitung zu verdrillenden Leitung, wobei aus den Messwerten oder charakteristischen Werten ein Korrekturwert für das Ablängen der zweiten oder jeder weiteren Leitung bestimmt wird.

Preference is given as further optional steps:

• motor-driven displacement of the twisting away from the jig after clamping the line and before the beginning of the actual twisting until the jig is moved by a predefined travel or a predefined force is applied,
• Measurement or at least indirect determination of a characteristic of the length of the line value from the then assumed position of the twisting head,
• Repeating the above steps with a second or each further line to be twisted together with the first line, wherein a correction value for the cutting of the second or each further line is determined from the measured values or characteristic values.

A further variant of the method according to the invention is characterized in that the twisting head moves away in a driving direction in the direction of the clamping device for each line type and / or twisting parameter, while the force caused by shortening the twisted lines counteracts the effect of a force-generating element the twisting head is shifted.

An advantageous preparation of the actual twisting process is possible by a variant of the invention in which before starting the actual twisting the lines to be twisted are loosely clamped, after which the lines are brought to a loose initial twisting by moving the twisting head to tension until the jig about half of the maximum travel has been shifted, wherein the clamping device is acted upon by a force away from the twisting head.

Quality monitoring of the twisting process, in particular in the case of an automated process sequence, is advantageously possible if the driving profile of the clamping device is evaluated during the twisting operation, whereby the exceeding of a predetermined limit for the travel path and the associated revolution is preferably monitored, so that a monitoring hose can be displayed which is at Demand requires a detailed assignment of the limit violation in association with the revolution.

Preferably, a variant according to the invention can provide that the driving profile of the twisting head is adapted as a function of the driving profile of the clamping device, preferably for a predefinable number of twisting operations with similar lines and twisting parameters.

Further advantages, features and details of the invention will become apparent from the following description in which with reference to the drawings embodiments of the invention are described. The features mentioned in the claims and in the description may each be essential to the invention individually or in any desired combination.

The list of reference numerals as well as the technical content of the claims and figures are part of the disclosure. The figures are described coherently and comprehensively. The same reference symbols denote the same components, reference symbols with different indices indicate functionally identical or similar components.

• Fig. 1 beispielhaft eine schematische Seitenansicht einer erfindungsgemässen Verdrillvorrichtung mit zwei Verdrillköpfen,
• Fig. 2 eine vergrösserte Einzeldarstellung der Baugruppe der Verdrillvorrichtung der Fig. 1 mit der zum Wegausgleich verschiebbaren Einspannvorrichtung in komplett zurückgefahrener Stellung,
• Fig. 3 eine vergrösserte Einzeldarstellung der Baugruppe der Fig. 2 in komplett ausgefahrener Stellung, und
• Fig. 4 ein Beispiel für einen pneumatischen Schaltplan für die Ansteuerung des Vorspannelementes für die Einspannvorrichtung.

It shows:

• Fig. 1 by way of example a schematic side view of a twisting device according to the invention with two twisting heads,
• Fig. 2 an enlarged detail of the assembly of the twisting the Fig. 1 with the clamping device displaceable for path compensation in completely retracted position,
• Fig. 3 an enlarged detail of the assembly of Fig. 2 in fully extended position, and
• Fig. 4 an example of a pneumatic circuit diagram for the control of the biasing member for the jig.

In the Fig. 1 shown twisting device with compensation of the theoretical length reduction in the twisting process has a twisting 1 on. On the opposite side of the twisting head 1, a pair of wires 3 to be twisted is held by a second twisting head 5, wherein the two twisting heads 1, 5 can be rotated in the opposite sense about a common axis of rotation. Instead of the second twisting head 5, a non-rotary clamping device may also be provided. The non-rotary clamping device can be provided as a variant and instead of the first twisting head 1, in which case the second twisting 5 is rotated. In principle, the twisting of three or more lines is also conceivable if the twisting heads 1, 5 or the clamping device, in particular their clamping mechanisms, are designed accordingly.

After passing the line pair 3 to the twisting heads 1, 5, the lines are initially arranged side by side in parallel and clamped at the ends in the grippers of the twisting heads 1, 5. Once the twisting process starts, the two will Lines by the action of at least the twisting head 1 twisted around each other, wherein the axial tensile force should be constant during twisting. However, a variable tensile force depending on the progressive twisting process may also make sense. By the twisting process, the length of the twisted wire 3 between the twisting heads 1, 5 is shortened. Shortening takes place as a function of the twist rotations after a parabolic function. The number of twist rotations required for the twist application is approximately equal to the length of the twisted pipe 3 (plot / job) divided by lay length. In addition, for example, about 40% of overdrive must be expected, which then have to be drilled back.

The length reduction in the twisting process can be described mathematically using the variables in the twisting process (eg line diameter, line material, line length, number of twist rotations (forward and backwards for decompression), traction during twisting and twisting length to be achieved as twisting result, etc.) , The parameters of the twisting process for a specific configuration of these variables can be saved as a file (so-called "recipe"). The basic data for these formulations are initially determined in preliminary tests for each line cross-section. Once basic data has been determined, the data for other line lengths can be derived mathematically.

The theoretical length reduction is implemented in the twisting process by the first twisting head 1 sitting on a length compensating slide 2, which can be actively moved by a programmable servo drive according to the required recipe during twisting and preferably according to the Verdrillumdrehungen and thus the shortening of the lines to be twisted third compensated during the twisting process. Theoretically, the axial tensile force in the cable pair 3 to be twisted would have to remain substantially constant, as is desirable for most twisting processes. On the basis of the appropriate recipe, however, a variable traction force profile could also be programmed via the twisting.

The second twisting 5 - or any non-rotary clamping device - sitting on another linear slide, a Wegausgleichsschlitten 4, which is acted upon by an adjustable biasing member with an adjustable biasing force, which force in a first twisting head 1 opposite and parallel to the common Rotary axis of the twisting heads 1, 5 oriented direction acts. Preferably, the carriage 4 is subjected to a constant and above all independent of the carriage position constant tensile force. The applied during the twisting on the lines 3 via the twisting head 1 axial tensile force corresponds to the force acting on the path equalizing slide 4 traction.

When conditioned by e.g. Material tolerances in the process the shortening of the twisted wire not exactly the programmed according to driving profile and moved target path of the length compensation slide under Verdriller 1, the path compensating slide 4 under the twisting 5 compensate for this difference. The traction remains the same.

As a biasing element, for example, a pneumatic cylinder 6 are used, a working space with adjustable and independent of the piston position constant pressure is applied. In this way, over the entire travel range of the length compensation carriage 2 by the compensating effect of Wegausgleichsschlittens 4 a defined tensile force, for example, over the entire travel range of both carriages 2, 4 are applied to the twisted pair of wires 3 during twisting. The pneumatic pressure to supply the cylinder 6 is - as in Fig. 4 shown in an exemplary pneumatic circuit diagram is set by means of a programmable pressure control valve, preferably a 5/2-way valve 44 by user interface. The pneumatic system comprises in total the compressed-air source 41, an electropneumatic regulator 43 inserted between the latter and the compressed-air accumulator 42, as well as two mufflers 47 at the outlet openings of the valve 44. A stopper 45 closes a path of the valve 44 parallel to the cylinder 6. The pneumatic cylinder 6 becomes supplied with the pneumatic pressure on one side, so that the existing on the piston rod traction over the entire travel range of the piston is constant. Material-related tolerances are compensated during the twisting by the now axially movable twisting head 2 according to the constant tensile force adapts its axial holding position.

Alternatively, it is also possible to vary in association with the Verdrillumdrehungen the pneumatic pressure and thus acting on the lines 3 tensile force, so that, for example, at the beginning of the Verdrillprozesses a lower tensile force acts, then a larger. Furthermore, alternative embodiments are possible in which the Pneumatic pressure and thus the biasing force of the cylinder 6 is driven to a programmed profile. This also applies to the subsequent re-twisting process.

The twist reduction to be compensated for by tolerances requires only a relatively short travel of the path compensating slide 4 mounted below the twisting head 5, in particular in comparison to the travel of the length compensating slide 2 for the first twisting head 1, typically in the range of approximately 40 mm. This is also by comparing the FIGS. 2 and 3 to recognize. If the position of the piston rod, of the carriage 4 or of the twisting head 5, ie the twisting head holding position, is monitored by means of a displacement sensor 7, the twisting process can thus be monitored well within the "normal" tolerances. Faults and faults outside of this normal twisting process will cause the monitoring tolerance tube to leave. This can be detected, processed and displayed by an evaluation unit. Also, further actions - cancel the twisting operation, leaving the pair of conductors as faulty, etc. - be triggered by it, so that a monitoring or quality control can be realized. Advantageously, the maximum possible travel path of the path compensating slide 4 is kept smaller by preferably adjustable stops 8a, 8b than the maximum travel path 8 of the length compensating slide 2.

According to the invention, the twisting process is thus divided into two movements. After the line 3 has been loosely clamped in both twist heads 1, 5, the line 3 is servomotorically brought to tension immediately or after a loose initial twisting with the length compensation until the twisting 5 or another, the twisting head 1 opposite jig about the middle of the possible Traversing the Wegausgleichschlittens has reached. The pneumatic cylinder 6 acts on the line 3 now with the set force constant. Then, the twisting is started and traversed by the length compensation of the twisting head 1 with a predetermined driving profile, wherein the twisting head 1 performs a computationally determined compensation ride to simulate the shortening of the lines to be twisted 3.

The second clamping device, in this case the second twisting head 5, drives against the first twisting head 1 (it can also move away from the twisting head 1 under certain conditions), the travel distance being dependent on the force preset on the biasing element 6 for tensioning the lines 3 while twisting. The twisting head 5 or the path compensating slide 4 supporting it only compensates small deviations from the ideal, programmed shortening of the cable.

A displacement sensor 7 or any other signal generator in conjunction with the second twisting 5 determines its driving profile during a twist and in an evaluation unit, the deviation of the line shortening is determined. For quality monitoring, the driving profile of the twisting head 5 is recorded and evaluated via the twisting of the line 3. A faulty twist can thus be detected over the entire course, even a statistical evaluation is possible

Furthermore, an optimization of the machine process is possible. For this purpose, the driving profile of the length compensation of twisting head 1, taking into account the balancing path of twisting 5 in the course of the first twists for similar lines 3 or similar Verdrillparameter is gradually adjusted.

• Überwachungsfähigkeit der Verdrillung bei exakt gleichbleibender Zugkraft im Automatikprozess.
• Prüfung / Überwachung der fertig verdrillten Länge
• Überwachung der Verkürzung bei Verdrillen als Qualitätsmerkmal
• Sehr sensibles Ansprechen der Längenkorrektur verhindert Belastungsspitzen der Leitungen
• Qualitätssteigerung der Verdrillung durch absolut gleichbleibende Zugkraft im automatischen Verdrillprozess
• Zugkraftprofil programmierbar im automatischen Verdrillprozess, mit Zugkraft zugeordnet zu den Verdrillumdrehungen bei fortschreitendem Verdrillprozess und/oder beim anschliessenden Rückverdrillen
• Verbesserte Erkennung einer Schlechtverdrillung
• Die Leitungen werden beim Verdrillen in axialer Richtung nicht überlastet.
• Prüfung / Überwachung der unverdrillten Leitungslänge

Further advantages of the device and the method according to the invention exemplified above:

• Monitoring ability of the twisting at exactly the same tensile force in the automatic process.
• Checking / monitoring the finished twisted length
• Monitoring the reduction in twisting as a quality feature
• Very sensitive response of the length correction prevents load peaks of the lines
• Increasing the quality of twisting by means of absolutely constant tensile force in the automatic twisting process
• Tensile force profile programmable in the automatic twisting process, with tensile force assigned to the twisting rotations as the twisting process progresses and / or during the subsequent reverse twisting
• Improved detection of poor twisting
• The cables are not overloaded when twisting in the axial direction.
• Checking / monitoring the untwisted cable length

A variant of the invention provides that the path compensating slide 4 or any arrangement having the same effect enables automatic determination of the driving profile for the first twisting head 1. The driving profile typically follows a parabolic function. If the actual values for the initial range of the parabola are known, the complete parabola can be calculated from this.

According to the invention two alternatively three or more to be twisted lines 3 are cut to length and clamped between the twist heads 1, 5. For this purpose, the line length is predetermined, preferably via a graphical user interface, so that the length compensation slide 2 can be positioned. The desired tensile force on the lines 3 is then adjusted to the pressure control valve 44 of the path compensation slide 4. Typical values are around 50N. Thereafter, the carriage 1 is moved back far enough that the carriage 4 of the twisting head 5 is pulled by the clamped lines 3 in the pneumatically controlled travel range.

Subsequently, the twisting operation is started at a slow speed of the twisting head 1 or the twisting heads 1, 5 and carried out until the carriage 4 has reached its Verfahrwegende. At the same time, the travel path in association with the revolutions is detected via the distance measuring sensor 7 of the carriage 4. Thus, the actual data for the beginning of the driving profile parabola are recorded. From this data, the parabola can be calculated including the continuing driving profile. Thus, the driving profile for the twisting head 1 and the length compensation slide 2 is programmable. The calculated driving profile is based on a relatively small number of actual data, so that the deviations of all other twisting operations must be corrected if necessary. The necessary corrections can be determined by means of the path sensor 7 of the path compensation slide 4 and used for the correction of the driving profile parabola.

A further advantageous application of the invention is to use the path compensating slide 4 for automated comparative measurement of the actual lengths of the two or more individually sequentially cut individual lines 3 in order to ensure the same length in the twisting region for both or more lines 3 to be twisted.

After the first line has been cut to length by means of the line feed and taken over into the grippers of the two twist heads 1, 5, the length compensating slide 2 is moved away from the opposite clamping device until the line 3 is tightened is and continues the path compensation slide 4 is moved and thus its set tensile force acts axially on the single line 3. The length compensation carriage 2 is then moved further to a defined reference point of the carriage 4, which is determined as a reference point by means of a value of the displacement sensor 7 or a fixed signal generator. The waypoint of the length compensation carriage 2 reached at this point (determined from the resolver data of its servomotor) is then stored.

The length compensation slide 2 is then returned to its original position, wherein the tensile force acting on the line 3 is reduced again to zero and the path compensating slide 4 moves back to its starting position and the measured line can be removed or ejected from the twisting heads 1, 5.

Thereafter, the same procedure is performed on the second line 3. By comparing the waypoint positions of the length compensation slide 2 for first and second and possibly further individual line 3, the difference length of the two lines can now be calculated. This difference measure can now be used for the correction of the Ablängvorganges the lines 3.

Claims (18)

1. Twisting device for electrical conductors, with at least one twisting head (1) that is drivable by motor power to rotate about an axis of rotation relative to a base, and a clamping device for the ends of the conductors (3) opposite of the twisting head (1), wherein the twisting head (1) is movable in the direction of its axis of rotation towards the clamping device, characterized in that the twisting head (1) is mounted on a first motorised length compensation carriage (2) which is movable automatically, wherein the clamping device is mounted on a travel compensation carriage (4) which is movable towards the length compensation carriage (2) in a direction essentially parallel to the axis of rotation of the twisting head (1), and to which a force acting essentially parallel to the axis of rotation is applied via a force generating element.
2. Twisting device according to Claim 1, characterized in that a further twisting head (5) which is rotatable in a direction opposite to that of the first twisting head (1) about a common axis of rotation is mounted on the travel compensation carriage (4) as a clamping device.
3. Twisting device according to Claim 1 or 2, characterized in that the travel compensation carriage (4) is displaceable passively and is subjected to a force directed away from the first twisting head (1) by means of a preload element.
4. Twisting device according to Claim 3, characterized in that the preload force of the preload element is adjustable at least before the start of activation of the length compensation carriage (2) drive means and preferably remains constant during the twisting process.
5. Twisting device according to Claim 3, characterized in that the preload element is a fluid cylinder, preferably a pneumatic cylinder (6) which is connected to a pressure source (41, 42, 43) via a controllable pressure control valve (44).
6. Twisting device according to any one of Claims 1 to 5, characterized in that the piston rod of the fluid cylinder (6) and/or the travel compensation carriage (4) is equipped or coupled with a displacement sensor (7) that is connected to an evaluation unit for determining and evaluating the travel profile of the travel compensation carriage (4).
7. Twisting device according to Claim 1 or 2, characterized in that the travel compensation carriage (4) is equipped with a force measuring sensor and a motorised drive unit as the force-generating element, wherein the travel compensation carriage (4) is subjected to a force that is directed away from the first twisting head (1) and variable as necessary depending on signals from the force measuring sensor, applied by the drive unit at least during the twisting process.
8. Twisting device according to Claim 7, characterized in that the drive unit or a control device of the travel compensation carriage (4) for the drive unit is connected to an evaluation unit for determining and evaluating the travel profile of the travel compensation carriage (4).
9. Twisting device according to any one of Claims 1 to 8, characterized in that a drive unit for the length compensation carriage (2) is activatable via a programmable controller to travel a travel profile prescribed for each conductor (3), conductor type and/or twist parameter, primarily towards the clamping device, and wherein the maximum possible displacement path of the travel compensation carriage (4) is kept shorter than the maximum displacement path (8) of the length compensation carriage (2) by preferably adjustable limit stops (8a, 8b).
10. Twisting device according to any one of Claims 1 to 9, characterized in that at least the drive unit of the length compensation carriage (2) is connected to a control unit in which a travel profile is stored for actuating the drive unit of the length compensation carriage (2) for each combination of conductors (3) and twist parameters.
11. Twisting device according to Claim 10, characterized in that a routine is implemented in the control unit which interrogates the evaluation unit and/or the displacement sensor (7), and generates a quality assessment and/or adapts the travel profile of the length compensation carriage (2) depending on the determined travel profile of the travel compensation carriage (4), optionally stores it in the control unit as the new travel profile for this combination of conductors (3) and twist parameters, and/or cancels the twisting process with an error message.
12. Twisting device according to Claim 10, characterized in that a routine is implemented in the control unit which controls the length compensation carriage (2) in such manner that the values delivered by the force measuring sensor lie within a prescribed range, and which depending on the determined travel profile of the travel compensation carriage (4) generates a quality assessment and/or adapts the travel profile of the length compensation carriage (2), optionally stores it in the control unit as a new travel profile for this combination of conductors (3) and twist parameters, and/or cancels the twisting process with an error message.
13. Method for twisting electrical conductors (3), comprising the steps of:

    - cutting the conductors (3) to size and transferring them to an actively displaceable twisting head (1) and an oppositely positioned displaceable clamping device,

    - clamping the conductors (3) between the twisting head (1) and the clamping device by moving at least the twisting head (1) away from the clamping device,

    - activating the twisting head (1) so that it rotates about an axis of rotation parallel to the clamped conductors (3) while at the same time actively moving the twisting head (1) towards the clamping device according to prescribed travel profile,

    characterized by the following steps:

    - applying a force directed away from the twisting head (1) and optionally of different magnitude to at least the clamping device, at least during the twisting process, and

    - determining and evaluating a travel and/or force profile for the displaceable clamping device.
14. Method according to Claim 13, characterized by:

    - motorised displacement of the twisting head (1) away from the clamping device after the conductor (3) has been clamped in place and before the actual twisting process begins, until the clamping device has been moved a predefined travel distance or a predefined force is exerted,

    - measuring or at least indirectly determining a characteristic value for the length of the conductor (3) from the position subsequently taken up by the twisting head (1),

    - repeating the above steps with a second or any further conductor (3) which is to be twisted together with the first conductor (3), wherein a correction value for cutting the second or any further conductor (3) to length is determined from the measured values or characteristic values.
15. Method according to Claim 13 or 14, characterized in that the twisting head (1) completes a pre-programmed travel profile towards the clamping device for each conductor type and/or twist parameter while the clamping device is shifted towards the twisting head (1) by the force created by the shortening of the twisted conductors (3) against the effect of a force-generating element.
16. Method according to Claim 13, characterized in that the conductors (3) to be twisted are clamped loosely before the start of the actual twisting process, after which the conductors are preferably brought to the required tension after a loose initial twisting by moving the twisting head (1) until the clamping device has been displaced by about half of its maximum travel path, wherein the clamping device is subjected to a force acting away from the twisting head (1).
17. Method according to Claim 13 or 14, characterized in that the the travel profile of the clamping device is evaluated during the twisting, wherein preferably exceeding a predetermined limit for the travel path and the assigned rotation are monitored, so that a monitoring range can be represented which if required enables a detailed assignment of events in which the limit values are exceeded with the rotation.
18. Method according to Claim 17, characterized in that the travel profile of the twisting head (1) is adapted according to the travel profile of the clamping device, preferably for a definable number of twisting processes with conductors (3) and twist parameters of the same kind.

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