EP0664765B1 - Method of winding a yarn on to a cross-wound bobbin - Google Patents

Abstract

Described is a method of winding a yarn (1), fed at constant speed by a feed mechanism, on to a cross-wound bobbin (4). The method calls for the drives (6, 8) for the bobbin spindle (5) and for the cross-winding device (3) to be controlled by frequency converters (30) controlled in turn by a bobbin control unit (14). In addition, the change in rpm as the bobbin diameter increases is controlled by a yarn-tension sensor (2). The correction of the frequencies of the power supply to the drives (6, 8) is carried out in such a way that a prescribed angle is maintained for the yarn being wound on to the bobbin (4) and the variation in yarn tension follows a prescribed pattern.

Description

The invention relates to a method for winding a thread into a cheese in a wild winding according to the preamble of patent claim 1.
Such a winding process is known, for example, from US Pat. No. 4,245,794.
When winding threads into packages, especially at high winding speeds, the lay-off angle and the cross-over ratio as well as the thread tension during the winding process are essential factors for the stability of the winding, the avoidance of mirror formation and the good workability of the winding during further processing and transport. For this reason, the general aim is to avoid deviations from experience-based favorable settings, in particular when suppressing mirror formation, if possible. On the other hand, it is known that the thread tension prevailing in the thread during the winding process generally also increases in an undesirable manner as the winding diameter increases, unless measures are taken to counteract an increase in the thread tension.

In the case of a wild winding, the back and forth movement of the Thread on the bobbin surface during the bobbin travel essentially with a constant traversing frequency, which at essentially constant thread delivery at constant thread lay-off angles leads on the coil surface. The wild winding is there especially distinguished from the precision winding, in which the winding spindle drive and the traversing drive mechanically or electronically in a fixed, non-integer Ratio and the lay angle with increasing coil diameter is steadily decreasing.

Measures to influence the thread tension during the winding process are in the prior art, for example the aforementioned US Patent 4,245,794 known.

In the method described in this patent between the thread delivery godet and receipt of the traverse Thread tension converter and a rotating one, depending on the oscillation speed controlled pulsation device intended. According to the winding process to be carried out on the device the pulsation device is said to be due to the oscillation caused thread tension fluctuations essentially compensate for the fact that through them the thread synchronously with the Traversing from its straight barrel deflected on both sides becomes. By the in the thread run in front of the pulsation device intended thread tension transducers are intended in particular thread tension changes caused by the increase in the bobbin diameter in control impulses to influence the spindle speed be converted so that an increasing Thread tension counteracted by lowering the spindle speed and vice versa.

However, this leads to the fact that depending on the thread tension curve also the placement angle and the crossing ratio be changed in an unforeseeable, undesirable manner.

The invention has for its object the management of the thread tension without influencing the crossing ratio and lay angle to make. This task is accomplished by the in the label part of the specified feature solved.

From US-PS 4,394,986 it is known, in a continuous winding method with a plurality of winding spindles which are alternately put into operation, both the drive motor for the winding spindle and the drive motor for the traversing device with an electrical correction signal obtained from the thread tension measurement act upon.
However, it should be noted that this only takes place during the change phase of the chuck and to accelerate the empty sleeve. During the entire winding cycle, it would be disadvantageous because, while simultaneously reducing the rotational speed of the winding spindle and traversing frequency in the same ratio as the winding diameter increases, the lay-off angle is continuously changed, which has disadvantages for the winding structure.
In contrast, in the method according to the invention, the winding ratio or the K-value, which are defined by the ratio of winding spindle speed and traversing frequency - as the number of double strokes - remains unchanged when the thread tension and thus the winding spindle speed change.

This prevents the thread tension and the control the winding spindle speed in the control of the traversing program intervenes. This is particularly advantageous for traversing programs, which is determined by the course of the winding ratio are, e.g. according to EP-0093258 B or US-4,504,024 A or EP-0195325 B or US-4,697,753 A. In the former (EP-0093258 B) this is Changier law depending on the occurrence of certain critical winding conditions controlled so that the traversing speed or traversing frequency when approaching one of these ratios on the other of two values is switched. In the second traversing program (EP 0195325 B) the traversing speed follows a predefined one Program.

In the simplest case, such a traversing program includes one constant traversing speed. Such one constant predetermined traversing speed can also Fluctuations are superimposed (wobble). With the well-known The traversing speed does not remain constant, but is between an upper limit and a lower limit changed according to a predetermined law, whereby also the upper limit and the lower limit change during winding change a thread to a package (winding trip).

Experience shows in both process variants that it is not it is possible to avoid any critical wind-up situation. In principle, critical wind-up situations are such which the traversing frequency and the spindle speed are an integer or form an integer fraction. Man describes these events as "mirror formation". The so-called "Mirror" not only represents a significant disturbance in the coil structure represents, but can also interrupt the winding process and to destroy the winding machine by occurring Lead out of roundness.

It turns out, however, that even when the winding ratio is not an integer or in winding conditions that are not a small whole number (2, 3, 4 ...) are broken, still mirror situations or mirror-like situations can occur. These situations are z. T. process-dependent and unpredictable.

Through the invention, such unpredictable winding conditions avoided.

A tolerance range is advantageous for the course of the thread tension given, for example, by targeted experiments or determined by experience from production can be. In particular, it should cover inevitable short-term fluctuations.

The nominal value of the thread tension can also be used as a long-term value Averaging can be determined and specified in experiments.

The winding method according to the invention is both in one Winding machine can be used with advantage, in which the bobbin drive by a driving roller driven at a constant speed Spool circumference takes place as well with a winding machine that an axle drive motor controlled by a feeler roller for the Has winding spindle.

Using the examples shown in the attached drawing a device for performing the method according to the invention the invention is explained.

Fig. 1

Schema einer erfindungsgemäß ausgestatteten Spulstelle mit direkt angetriebener Spulspindel;

Fig. 2

Funktionsschaubild einer Spulstelle mit Antrieb der Spulspindel durch eine Treibwalze;

Fig. 3

Funktionsschaubild einer Spulstelle mit Direktantrieb der Spulspindel.

Show it:

Fig. 1

Scheme of a winding unit equipped according to the invention with a directly driven winding spindle;

Fig. 2

Functional diagram of a winding unit with drive of the winding spindle by a drive roller;

Fig. 3

Functional diagram of a winding unit with direct drive of the winding spindle.

Fig. 1 shows the construction scheme for performing the winding station equipped according to the winding method according to the invention, in which the thread 1 through a winding spindle 5 with feeler roller 24 and direct drive 6 is wound into a cheese 4. The drive shaft 7 of the oscillation 3 also has its own Drive 8. Both drives 6, 8 are via converters 30 and Supply lines 28, 29 guided by a control unit 9. Instead of being driven directly by the motor 6, it is alternatively also known and customary, the cheese 4 on her Circumference driven by a constant circumferential speed To drive the driving roller.

The control unit 9 has the task of the drives 6, 8 in mutual To coordinate dependency so that the Crossing ratio and the laying angle with those for the whole Predetermined setpoint curves in accordance being held. For this purpose, the target and actual values and the frequencies for the spindle drive 6 (frequency generator 19) and the drive 8 of the oscillation 3 (frequency generator 18), the actual speed 22 of the winding spindle 5 or the number of double strokes Traversing 3 (speed 21 of the drive shaft 7), the course of the Thread tension (setpoint 20, actual value 23) and - with direct drive the winding spindle 5 - the peripheral speed determined by the feeler roller 24 25 entered the coil 4 in the control unit 9.

Between a not shown, at a constant speed driven delivery plant, for example one from Thread entwined godet and the entrance of the traversing triangle Forming head thread guide 10 is an adjacent to the thread 1 Thread tension transducer 2 is provided via a signal line and not one because of the better clarity shown D / A converter (digital-analog / converter) the course the measured thread tension (signal 23) to the control unit 9 transmitted. By coming from the thread tension sensor 2 Signals become the predetermined setpoints in the control unit 9 modified for guiding the drives 6, 8 so that with that required to compensate for thread tension deviations Changing the spindle speed also means changing the The traversing speed is such that the specified one The course of the crossing ratio and the lay angle remain unchanged preserved.

The functional diagrams shown in Figures 2 and 3 agree in essential parts and are therefore with the provided the same reference numerals for the comparable units.

Both are specified by the fundamental frequency generators 11 (for traversing) and 12 (for spool drive) generated fundamental frequencies and the setpoint curve 20 of the Thread tension. The generators 11, 12 generate the corresponding setpoints 18, 19 specified by the winding program respective basic frequencies for the coil drive and the traversing drive, which of the winding head control belonging to the control unit 9 14 are supplied. In the supply line from which the Fundamental frequency 18 of the oscillation generating generator 11 for Spool head control 14 (connection CH) is a disturbance generator 13 provided that the generation of the setpoint 18 of the traversing signals to be given for the intended interference procedure (e.g. B. wobble) serves to suppress the mirror image. In the to a winding device with a directly driven winding spindle (Fig. 1) belonging to Fig. 3 is also in that of the fundamental frequency generator 12 leading to connection S of the winding head control 14 Line a spindle drive control 17 is provided.

The winding head control 14 are continuously determined Actual values, namely 21 of the oscillation 3 (double stroke rate, oscillation frequency), 22 of the winding spindle speed and 23 of the thread tension and in the embodiment according to FIG. 3 also by the feeler roller 24 determined coil circumferential speed (signal 25), fed. In addition, the actual values go to a control unit 9 belonging unit 16 for actual value acquisition, the Actual value signal 23 of the thread tension to a control unit 15 for the thread tension is passed on. The control unit 15 Correction signals generated pass through line 26 to Connection S (winding spindle) of the control 14 and via the line 27 to the interference generator 13 and from there together with the interference signals to the CH connection of the winding head control 14 both inputs of the controller 14 from the fundamental frequency generators 11, 12 generated signals by multiplicative evaluation with the same evaluation factor depending on the thread tension modified.

3 is also in the for Line belonging to the winding spindle drive from the fundamental frequency generator 12 for the winding head control 14, a control 17 for the winding spindle drive intended. The coming from the actual value acquisition 16 to the actual values 22 (winding spindle speed) and 25 (scanning roller speed) belonging signals get here in the Control 17, the actual value signal 22 of the spindle speed reaches as well as the actual value signal 21 of the traversing to the disturbance generator 13.

In the winding head control 14, the over in both cases Inverters 30 are supplied to the drives 6, 8 in this way modified that without disturbing the given crossing ratio and the lay-off angle the actual value curve of the thread tension is adapted to the course of the setpoint.

It should also be pointed out here that this is shown in FIG. 1 to 3 described method for controlling the drives 6,8 a winding spindle 5 and the traversing 3 assigned to it on a winding device with several, on a reel turret arranged winding spindles is applicable, the winding spindles likewise either by a direct drive 5 according to FIG. 3 or a friction roller drive according to FIG. 2 can be driven.

REFERENCE SIGN LISTING

1

thread

2nd

Thread tension sensor

3rd

Traversing

4th

Winding, spool

5

Winding spindle, direct drive

6

Winding drive

7

drive shaft

8th

Traverse drive

9

Control unit

10th

Head thread guide

11

Basic frequency generator oscillation

12th

Basic frequency generator coil drive

13

Vibration disturbance generator

14

Spooling head control

15

Thread tension control

16

Actual value acquisition

17th

Spindle drive control

18th

Setpoint frequency change

19th

Target frequency winding spindle drive

20th

Thread tension setpoint

21

Actual value change

22

Actual value of spindle speed

23

Actual thread tension value

24th

Sensing roller

25th

Actual value of coil circumferential speed

26

Signal line

27

Signal line

28

power supply

29

power supply

30th

Converter

Claims (4)

1. Method for winding a thread (1) to form a cross-wound bobbin (4) by random winding, in which

   a) the thread (1) is delivered to a fixed thread guide (10) by a delivery device which is driven at a constant rotational speed;

   b) the thread (1) is laid to and fro by a traversing device (3, 7 8), forming a traversing triangle between the thread guide (10) and the surface of the bobbin;

   c) the traversing device (3, 7, 8) has a traversing drive (8) by which the thread (1) is deposited on the cross-wound bobbin (4) in dependence on a predefined traversing setpoint value (18), at delivery angles which are non-dependent on the bobbin diameter;

   d) the thread tensile force (23) is measured between the delivery device and the fixed thread guide(10),

   e) the cross-wound bobbin (4) is mounted on a winding spindle (5) which is driven by its own winding spindle drive, and

   f) the circumferential speed of the bobbin (4) is varied in dependence on the measured thread tensile force (23) in such a way that the thread tensile force (23) assumes a predefined value (20),
   characterized in that

   g) the circumferential speed of the bobbin (4) is regulated in dependence on the difference between a predefined circumferential speed setpoint value (19) and a measured circumferential speed actual value and in that the circumferential speed setpoint value (19) is additionally varied in dependence on the measured thread tensile force (23) in such a way that the thread tensile force (23) assumes the predefined value (20), and

   h) the traversing setpoint value (18) for the traversing drive (8) is simultaneously varied in the same ratio by which the circumferential speed setpoint value (19) of the bobbin (4) is varied in dependence on the measured thread tensile force (23).
2. Method according to Claim 1, having the further features:

   a) a winding program is predefined with speed setpoint values (19) for controlling the winding spindle drive (6) in such a way that the cross-wound bobbin (4) is driven with a predefined circumferential speed characteristic;

   b) the speed setpoint values (19) are varied in the same ratio, dependent on the thread tensile force (23) as the traversing setpoint values (18).
3. Method according to either of Claims 1 or 2,
   characterized in that
   the winding spindle drive is a driving roller, bearing against the circumference of the cross-wound bobbin (4), with a driving roller motor to which the speed setpoint values (19) are input;
4. Method according to either of Claims 1 or 2,
   characterized in that

   a) the winding spindle drive is a spindle motor (6);

   b) bearing against the circumference of the cross-wound bobbin (4) there is a sensing roller (24) whose rotational speed (25) is continuously measured, and

   c) the spindle motor (6) is controlled in dependence on the measured rotational speed (25) and in dependence on the predefined speed setpoint values (19).

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