EP0027173B1 - Method for winding yarns - Google Patents

Description

The invention relates to a method for winding threads, in particular man-made fibers delivered at a constant speed, into wildly wound cross-wound bobbins, in which the traversing stroke length is shortened cyclically in a shortening cycle in the range of a maximum difference value compared to its predetermined maximum value, in an extension cycle to the predetermined one Maximum value is extended again and kept unchanged in a rest cycle.

When winding threads into cross-wound bobbins, in particular cylindrical and biconical cross-wound bobbins in a wild winding, hard and, under certain circumstances, thickened areas arise on the end edges of the bobbins. You counter this with the so-called »breathing«. The breathing stroke length is shortened cyclically during breathing. The respiratory tract or respiratory stroke (traverse stroke shortening, stroke shortening) depends on the titer. Shortenings of up to 10 mm are conceivable.

It has been found that breathing according to the known method of working does not yet completely solve the problem of the thickened and hardened areas of a cheese. Rather, it is sometimes observed that hardened areas form both on the front edges of the coil and at the end of the breathing path.

To solve this problem, the invention proposes that the breathing stroke - defined as the difference between the maximum and the smallest traversing stroke length of a breathing cycle - be changed several times during the winding cycle.

Experiments have shown that even in the area of the coil ends a uniform hardness of the coils and an exactly cylindrical structure can be achieved.

The breathing stroke can preferably be changed continuously from one breathing cycle to another, in particular in a non-periodic manner. This is technically solved in particular so that a sequence of numbers generated by a random number z. B. predefined directly or via a memory and the breathing path or breathing stroke in the successive breathing cycles is determined according to this sequence of numbers.

For this purpose, either the shortening speed can be changed according to the sequence of numbers, whereby the duration of the shortening cycle of breathing remains constant, or the duration of each shortening cycle or constant each breathing path can be changed according to the specified sequence of numbers if the shortening speed is constant for the winding cycle.

With breathing and in particular also with the type of breathing according to the invention, it has proven to be advantageous to keep the traversing stroke length constant at its maximum value for a certain time. In the context of this application, this time of the constant maximum traversing stroke is referred to as the resting time TR.

It can be provided within the scope of the above-mentioned proposals according to the invention that the ratio of the rest cycle to the entire movement cycle of a breathing cycle (sum of the duration of the shortening cycle and the extension cycle) is kept constant for the entire winding cycle.

This ratio, referred to in this application by k, is preferably greater than _^1/4 and less than ^_1/2.

The adjustment of the traversing stroke is carried out by a breathing motor for adjusting a device such as that used for. B. is shown in DE-C 1 916 580. This respiratory motor is preferably operated at the same speed during the shortening and lengthening of the traversing stroke, so that the duration of the shortening cycle of breathing is equal to the duration of the extension cycle.

The invention is based on the further problem that a so-called mirror formation is possible when winding threads into cross-wound bobbins in a wild winding, in which two layers of threads lie directly one on top of the other. In this case, the bobbin and the threads are damaged. The problem of mirror formation is avoided by the so-called "mirror disturbance".

For mirror disturbance, the traversing speed is usually changed continuously in a predetermined range of a maximum and a minimum traversing speed.

When combining the present invention with the older method of mirror disturbance according to DE-A 2 855 616, mirror disturbance and breathing can be coupled with one another in such a way that, according to claim 8, the times of greatest traversing speed and shortest traversing stroke length coincide. Under the same condition, the start of each breathing cycle with the start of the acceleration of the traversing speed for the purpose of mirror disturbance can be started with two or more than two alternately controlled time relays with different time constants. It has been shown that the best results in terms of coil structure, coil hardness and coil shape are achieved if the breathing is changed according to the invention and coupled with the mirror disturbance.

Preferably, the mirror disturbance and the breathing are coupled to one another in such a way that the rise clock of the mirror disturbance (ie the timing for increasing the traversing speed) and the shortening clock of breathing (ie the timing for shortening the traversing stroke) are synchronous, while the sum of the extension cycle (that is, the timing for the extension of the traversing stroke) and the rest cycle (that is, the timing of the constant maximum traversing stroke) are identical in time to the descent cycle of the mirror disturbance (that is, the timing of the reduction in the traversing speed).

The method set out in claims 8 to 11 can be carried out in that the acceleration amounts and the deceleration amounts of the traversing speed remain constant during each cycle of the mirror disturbance and over all cycles of the mirror disturbance of a winding trip, the amount of retardation of the traversing speed in each descent cycle Mirror disturbance is chosen so that the mirror disturbance occurs by changing the traversing speed above a minimum traversing speed which is constant for the winding travel. The amount of acceleration can preferably be greater than or at most equal to the amount of deceleration of the traversing speed. This proposal is characterized in that the mirror disturbance stroke - as the difference between the respectively maximum traversing speed and the minimum traversing speed which is constant over the winding travel - is proportional to the respiratory stroke. The advantage of this solution is that it is technically easy to implement. The drive for the mirror fault remains constant during the winding cycle. There is only a switchover from acceleration of the traversing speed to deceleration or from deceleration of the traversing speed to acceleration at the beginning and end of the shortening cycle of breathing, which is predetermined by a sequence of numbers, preferably a random number sequence, with a predetermined ratio of the acceleration amount to the delay amount.

Such a coupling of breathing and mirror disturbance is quite sufficient for many applications. For some applications, however, there is a disadvantage in that the average traversing speed and thus also the crossing angle can only be specified very imprecisely. If such an average traversing speed is to be predeterminable, the invention can be carried out by continuously changing the duration of the shortening cycle of breathing for each breathing cycle, while the traversing speed is first accelerated beyond the predetermined mean value during each shortening cycle of breathing, and that the deceleration amounts of the traversing speed are continuously adapted to the respective maximum value of the traversing speed in such a way that the maximum traversing speed and the minimum traversing speed are symmetrical to the predetermined mean traversing speed in a descent cycle.

gilt (b = Beschleunigungs-, v = Verzögerungswert).In practice, this can be achieved by setting the acceleration values and the deceleration values of the traversing speed in a certain relationship to one another, such that the formula for each breathing cycle

applies (b = acceleration, v = deceleration value).

In the solution specified in claim 12, the acceleration values and deceleration values in the previously described predetermined ratio depend on the minimum traversing speed initiating the respective mirror disturbance stroke and the respective mirror disturbance stroke as the difference between the maximum and the minimum traversing speed of the mirror disturbance cycle. The dependence of the acceleration values is such that a maximum traversing speed which is above the predetermined mean traversing speed is achieved in each rise cycle of the mirror disturbance. It can therefore be provided for the implementation of the invention that the controller for coupling breathing and perturbation also contains a computer which calculates the acceleration value and the deceleration value for the traversing speed with a lead time before each breathing and mirror disturbance cycle.

However, it is preferred that, according to claim 13, a sequence of numbers for the change in breathing and the values for the acceleration values and the deceleration values of the traversing speed which are to be assigned to this sequence of numbers are stored in a memory for synchronous retrieval. The latter values can be determined as a function of the differences in the numbers, which in their sequence determine the respective shortening cycle of breathing.

Finally, according to a further proposal according to claims 13 to 15, the change in the shortening cycle duration of the breathing and the breathing stroke, in particular at a constant shortening speed, are controlled by changing the resting clock period. Here, the duration of the breathing cycle consisting of shortening cycle, extension cycle and resting cycle can remain constant over the winding cycle.

The invention can be carried out by a large number of controls, in which case an electronics specialist must be consulted.

The control, which is only shown schematically, is constructed in such a way that it can carry out the functions of mirror disturbance and breathing shown in FIGS.

• Fig. 1, 2 und 4 Diagramme der Changiergeschwindigkeit und des Changierhubes für verschiedene Ausführungsbeispiele; Fig. 3 ein Blockschaltbild der Steuerung;
• Fig. 5 den Schaltplan für eine Steuerung des Ausführungsbeispiels nach Fig. 4.

Embodiments of the invention are explained below with reference to FIGS. 1 to 5. Show it

• 1, 2 and 4 diagrams of the traversing speed and the traversing stroke for different exemplary embodiments; Fig. 3 is a block diagram of the controller;
• 5 shows the circuit diagram for a control of the exemplary embodiment according to FIG. 4.

Zum Begriff der »Changiergeschwindigkeit« sei hier noch folgendes bemerkt:In Figures 1 to 4, the letter designations mean:

The following should be noted here regarding the term "traversing speed":

The "traversing speed" is the speed of the traversing thread guide.

In connection with the mirror disturbance, the traversing speed is expressed in double strokes (back and forth stroke) per minute, also referred to as »number of strokes« for short.

For example, a traversing device can have an average speed of 100 double strokes (DH) per minute, the number of strokes being able to move between 95 and 105 (DH / min) to avoid mirror formation. The traversing speed changes continuously between the specified maximum and minimum values.

In connection with breathing, the traversing speed is expressed in m / min. If breathing alone - i.e. no mirror disturbance - is used, the number of strokes (DH / min) remains constant during the winding travel, and only the traversing stroke length changes during the winding travel given time periods. In this case the traversing speed in m / min results from:

Double strokes per minute [DH / min] - stroke length per double stroke [m / DH] If the stroke length changes, the traversing speed also changes, expressed in m / min.

With the combination of mirror disturbance and breathing, the traversing speed is influenced both by the number of strokes (number of double strokes / min) and by the change in the traversing stroke length (m / DH). In the context of this invention, the traversing speed is expressed as the number of double strokes / min [DH / min], although the influence of breathing on the change in traversing speed can be of the same order of magnitude as the influence of mirror interference on the change of traversing speed.

It should be mentioned in advance that in the diagrams according to FIGS. 1 and 2 the factor k = TR / TB = ½.

The essential criterion of the mirror disturbance according to FIG. 1 is that the acceleration of the traversing speed, which is represented by the tangent of the rise angle alpha, remains constant over the entire winding travel. The same applies to the deceleration of the traversing speed, which is represented by the tangent of the descent angle beta. It should be noted that alpha and beta are not the same as each other, but that beta is preferably smaller than alpha. In principle, it is also possible to provide the control in such a way that the descent angle beta is greater than the ascent angle alpha. For breathing, the speed for shortening and lengthening the traversing stroke, which are each represented by the angles gamma and delta, are constant over the entire winding travel.

Both the acceleration and deceleration values of the traversing speed and the speed of the stroke shortening can be set for the winding travel in terms of their absolute amount.

die Zeitdauer für den Verlängerungstakt TL und den Ruhetakt TR der Atmung bestimmt wird.In Fig. 1, the duration of the breathing cycle TA is variably specified from one cycle to another. This can be done by specifying either the duration of the shortening cycle TK of each breathing cycle TA or the breathing stroke 4A of each breathing cycle using a sequence of numbers, preferably an arbitrary, ie non-periodic sequence of numbers, and then based on the boundary conditions:

the time period for the extension clock TL and the resting clock TR of breathing is determined.

im vorgegebenen Beispiel = 2 ist. In Fig. 1 ist dies darin abzulesen, daß tan alpha = 2 tan beta ist.The traversing speed is then switched over to its constantly predetermined acceleration value at the constantly predetermined acceleration value at the beginning and end of the respective shortening cycle of breathing. The delay is calculated in advance so that the traversing speed after each full breathing cycle TA again reaches its minimum traversing speed which is constantly predetermined for the winding travel. This means that the ratio of the absolute amounts of

in the given example = 2. In Fig. 1 this can be read from the fact that tan alpha = 2 tan beta.

As can be seen from FIG. 1, no average traversing speed for the winding travel can be predetermined with this solution.

In the solution according to FIG. 2, the breathing cycle is again specified for each breathing cycle TA by either specifying the duration of the shortening cycle TK or the respiratory path AA according to a number sequence programmed into a memory.

According to the invention, breathing and perturbation are coupled to one another in such a way that the times of greatest traversing speed VS max and smallest traversing stroke length HCH min _i coincide.

In the shortening cycle TK, the traversing speed VS is increased in such a way that, taking into account its output value at the end of the shortening cycle TK or the rising clock TAN, it is greater than the average traversing speed VS medium, which is constantly predetermined for a coil. The acceleration of the traversing speed is therefore dependent on the one hand on the minimum traversing speed VS mini achieved at the beginning of the rise cycle and on the other hand on the length of the predetermined rise cycle or shortening cycle of the breathing cycle. This acceleration value of the traversing speed VS can either be specified with a short lead time before each shortening cycle TK by a computer connected to the controller, which detects the minimum traversing speed VS min _i at the beginning and the duration of the rising clock TAN. However, it is technically simpler for the sequence of numbers entered into a memory, which determines the shortening cycles TK of breathing for the entire duration of the winding travel, the required acceleration values of the traversing speed VS, which is the condition mentioned above are sufficient to calculate in advance and also store and retrieve from the memory with each number of the number sequence for the shortening cycle TK of a breathing cycle.

ermittelt.The deceleration of the traversing speed, which is represented by the tangent of the angle beta, is chosen for each descent cycle TAB of the mirror disturbance such that the maximum traversing speed VS max and the minimum traversing speed VS min; of this descent cycle are symmetrical to the average traversing speed VS medium specified for this coil. In order to achieve this, a prediction of the delay value, which is represented by the tangent beta, is again required. This can also be done by a computer which, on the one hand, achieves the maximum traversing speed VS max; this mirror disturbance cycle and the duration of the shortening cycle TK of respiration or the duration of the rise cycle TAN of the increase in the traversing speed VS are detected and therefrom

determined.

Corresponding values can, however, also be calculated in advance and then again entered into a memory with the corresponding acceleration values and specified for the mirror disturbance with each descent cycle TAB of the control device.

It is hereby achieved that the traversing speed VS always oscillates around the mean traversing speed VS given for the spool, so that the spool is to be constructed with a pre-calculated mean value of the crossing angle.

In the block diagram according to FIG. 3, the frequency generator 1 and the counter 2 generate an actual time signal which is given to the changeover switch 3. A set time signal is generated by the time preset memory 4 and is likewise given to the changeover switch 3. In accordance with the actual time signal, the breathing control 6 is first switched to shortening and then to an extension of the traversing stroke and then to a constant traversing stroke. The duration of the shortening cycle TK, extension cycle TL and rest cycle TR can be stored directly in the time preset memory 4.

The output signal of the changeover switch 3 is simultaneously given to a timer 5 which, via the converter 7, gives a positive or negative voltage signal to the control device 8 for the mirror disturbance in alternating sequence if the target time signal and the actual time signal match. The amplitude of the mirror interference can be influenced by the additional control device 9.

In this form, the control device can be used for the embodiment of the invention described with reference to FIG. 1.

For the exemplary embodiment according to FIG. 2, the control is to be supplemented by a memory device 10, which converts the output signal of the converter 7 in such a way that the mirror interference is operated with the pre-calculated acceleration and deceleration values.

In FIG. 4, the traversing speed between the maximum value VS max and the minimum value of the traversing speed VS min is continuously changed in constant cycle times TS for the purpose of mirror interference. For this purpose, the drive motor for traversing during the drive time TAN of the mirror fault is accelerated as a function of an additional drive pulse on a drive line 15 (FIG. 5), which is omitted during the descent time TAB of the mirror fault.

The breathing cycle TA is identical to the cycle TS of the mirror disorder. In the exemplary embodiment, the breathing stroke is between a maximum breathing path HCH max and a minimum breathing path HCH min; continuously changed in four stages. This is done by starting each breathing cycle with a rest period TRA, for which four different values are preprogrammed. Otherwise, the motor which causes the change in the traversing stroke HCH is switched so that it changes its direction of rotation when the pulse on the control line 15 ceases to exist and thus increases the traversing stroke again until it reaches a limit switch 43 when the maximum traversing stroke HCH max is reached (Fig. 5) drives, which puts the engine out of operation again. It then remains out of operation for the time period TRE until the next breathing cycle TA is started with another of the preprogrammed initial rest periods TRA.

This breathing with a modified breathing stroke _L 1A and its synchronization with the mirror disturbance is carried out by a circuit according to FIG. 5. The heart of this circuit is the timing relays 11, 12, 13 and 14, to which different time constants are programmed. These time constants correspond to the initial rest periods TRA1, TRA2, TRA3, TRA4. The timing relays 11 to 14 are controlled by the so-called step-up relays 16 and 17 as a function of the pulse on the control line 15.

Step-by-step relays are commercially available components that assume a predetermined switching position due to an input pulse and which are retained even when the pulse is removed.

• Relais 22 die Schalter 26 und 27
• Relais 23 die Schalter 28 und 29
• Relais 24 die Schalter 30 und 31
• Relais 25 die Schalter 32 und 33

The switching relays 22 to 25 are controlled by the switching relays 16 and 17 via the switches 18 to 21. It operates

• Relay 22 switches 26 and 27
• Relay 23, switches 28 and 29
• Relay 24, switches 30 and 31
• Relay 25, switches 32 and 33

These switches 26 to 33 are connected in series with the time relays 11 to 14 in pairs. The lines 34 to 37 come from a control transformer, not shown. The pulses on the control line 15 determine the start of the cycle for the mirror disturbance and breathing and, in addition, also the changeover time for the deceleration of the traversing speed VS and the extension of the traversing stroke HCH.

• Impuls 1 betätigt die Relais 22,23 und das Zeitrelais 11
• Impuls 2 betätigt die Relais 23,24 und das Zeitrelais 12
• Impuls 3 betätigt die Relais 22,25 und das Zeitrelais 13
• Impuls 4 betätigt die Relais 23,25 und das Zeitrelais 14

Due to the continuous series of pulses, the relays and timing relays are operated as follows:

• Pulse 1 actuates relays 22, 23 and timing relay 11
• Pulse 2 actuates relays 23, 24 and timing relay 12
• Pulse 3 actuates relays 22, 25 and timing relay 13
• Pulse 4 actuates relays 23, 25 and timing relay 14

The time relays 11 to 14 control corresponding switches 11'-14 'after the preset initial sleep time TRA1 to TRA4 has elapsed. Via this switch, the motor (respiratory motor) 38 with the direction of rotation 39 for reducing the traversing stroke is set in motion by the relay 40 and the switch 41 when or since the switch 42 is closed by the pulse on the control line 15. As soon as the pulse on line 15 drops, switch 42 is opened. However, since the motor 38 has now moved from the limit switch 43, the motor 38 with the direction of rotation 46 is now switched over via the relay 44 and the switch 45 to increase the traversing stroke. The motor 38 remains in operation until it opens the limit switch 43 again. It is only put back into operation when another time relay is activated and the pulse on control line 15 reappears. The lines 47 and 48, via which the motor 38 is controlled on the one hand by the time relays 11 to 14 and on the other hand by the limit switch 43, are interlocked with one another by the relays 40 and 44 already described and the switches 49, 50.

It has been found that the change in the breathing stroke between two, three, four or another limited plurality of values in many fields of application - such as e.g. B. when winding textured by false twisting man-made fibers - can achieve a very good winding structure without thickened edges, running difficulties or damage to the thread.

In other areas of application of the invention - such as. B. when winding up smooth man-made fibers - a continuous and possibly non-periodically repeating change of the respiratory tract is preferable, the required technical effort being adapted to the requirements of the winding process.

Claims (15)

1. Method for winding yarns, particularly man-made fibres which are delivered at a constant speed, into a cross wound package, in which method the length of the traverse stroke (HCH) (of the yarn guide) with respect to its predetermined maximum length (HCH max) is periodically shortened within a maximum differential range (dA max) during a stroke length shortening period (TK), and is increased during a stroke length increasing period (TL) onto said predetermined maximum length of the traverse stroke (HCH max), and remains unmodified during a rest period (TR) (stroke modification = »breathing«), characterized by the fact that the length of stroke modification (dA) - which is the difference between the maximum length (HCH max) and the minimum length (HCH mini) of the traverse stroke of a stroke modification cycle (TA) - is repeatedly changed during the package winding cycle.

2. Method according to claim 1, characterized by the fact that the length of stroke modification (dA) is changed continuously from one stroke modification cycle (TA) to another.

3. Method according to claim 1 or 2, characterized by the fact that the length of stroke modification (dA) is changed aperiodically.

4. Method according to any of the claims 1 to 3, characterized by the fact that the length of stroke modification (dA) is changed by varying the rate at which the length of stroke is shortened, while the duration of the stroke length shortening period (TK) remains constant.

5. Method according to any of the claims 1 to 3, characterized by the fact that the length of stroke modification (dA) is changed by varying the duration of the stroke length shortening period (TK), while the rate at which the stroke length is shorttened remains constant.

6. Method according to any of the claims 1 to 5, characterized by the fact that the duration of the stroke length shortening period (TK) is equal to the duration of the stroke length increasing period (TL).

7. Method according to claims 2 and 6, characterized by the fact that the ratio (k) of the rest period (TR) and the sum of the stroke length increasing period (TL) and stroke length shortening period (TK) is maintained constant during the entire package winding cycle, with the following formula preferably applying to said ratio (k):

8. Method according to claim 1, characterized by the fact

that - in order to avoid pattern formation - the traverse motion speed (VS) is continuously accelerated during a period of acceleration (TAN)

and is decelerated during a period of deceleration (TAB) within a range of maximum speed (VS max) and minimum speed (VS min),

and that pattern breaking and stroke modification are correlated in such a manner that the moments of maximum traverse motion speed (VS maxi) within each traverse stroke cycle coincide with the moments of minimum length (HCH mini) of said traverse stroke cycle.

9. Method according to claim 8, characterized by the fact that the amount of acceleration (|b|) of the traverse motion speed (VS) exceeds, or is equal to, the amount of deceleration (|v|) of the traverse motion speed (VS).

10. Method according to claim 8 or 9, characterized by the fact that, in order to avoid pattern formation, the starting time of each stroke modification cycle (TA) is synchronized with the starting time of the acceleration of the traverse motion speed (VS) by means of two or more alternately actuated timing relays (11,12,13,14), each of which is subjected to a different time constant.

11. Method according to claim 8 or 9, characterized by the fact that the period of acceleration (TAN) of the traverse motion speed (VS) is synchronized whith the stroke length shortening period (TK) of the stroke modification cycle, so that the stroke length increasing period (TL) and the rest period (TR) of the stroke modification cycle occur at the same time as occurs the period of deceleration (TAB) of the traverse motion speed (VS).

12. Method according to claim 11, characterized by the fact that the duration of the stroke length shortening period (TK) is changed for each stroke modification cycle (TA),

that the traverse motion speed (VS) exceeds a predetermined average value (VS mittel) during the stroke length shortening period (TK) of the stroke modification cycle,

and that the amounts of deceleration of the traverse motion speed (VS) are determined in such a manner that during the deceleration period (TAB) the maximum and minimum traverse motion speeds (VS) are symmetrical with respect to the predetermined average traverse motion speed (VS mittel).

13. Method according to claim 12, characterized by the fact,

that the duration of the stroke length shortening period (TK) of the stroke modification cycle is controlled by a memory fed with a sequence of numbers,

and that the amounts of acceleration or of deceleration for the traverse motion speed (VS) are produced as a function of the differences of the numbers of that number sequence which controls the stroke length shortening period (TK) of said stroke modification cycle.

14. Method according to claim 8, characterized by the fact that the duration of the stroke length shortening period (TK) of the stroke modification cycle is changed and the length of stroke modification (LfA) is determined by control of the duration of the rest period (TRA, TRE), particularly while the rate at which the length of stroke is shortened is maintained constant.

15. Method according to claim 14, characterized by the fact that the duration of the stroke modification cycle (TA) consisting of the stroke length shortening period (TK), the stroke length increasing period (TL) and the rest period (TR) is constant during the entire package winding cycle.

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