JPH07252729A - Method and apparatus for winding up yarn - Google Patents

Abstract

PURPOSE: To form an optimum wound body while preventing ribboning by making a non-periodic change of traversing velocity in accordance with the change of the maximum value and the minimum value and the change of time limit between inversion points of a sweep trace. CONSTITUTION: The non-periodic change of the traversing velocity Vc is executed as follows when yarn is fed at a fixed velocity and is wound up in the coarse cheese winding form. To determine the non-periodic sweep trace 10, the maximum value and the minimum value of the traversing velocity are changed to the maximum 10a and the minimum 10b of the non-periodic sweep trace, respectively, and the time limit between the maximum 10a of the sweep trace and the subsequent minimum 10b or the time limit between the minimum 10b of the sweep trace and the subsequent maximum 10 is changed at random within a prescribed limit. The acceleration and delay in the traversing velocity are kept constant between these inversion points 10a, 10b of the sweep trace.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for winding a yarn, comprising: a) feeding the yarn at a constant speed; b) winding it into a coarse cheese roll; c) ribbon winding. The invention relates to a method for winding a yarn in the manner of making an aperiodic change of the twill speed (aperiodic sweep line (Wobbelkurve)) and an apparatus for carrying out this method.

[0002]

2. Description of the Related Art When winding a yarn, the yarn is fed to a winding device at a constant speed through a thread guide which usually moves parallel to the bobbin axis. In particular, when winding the yarn around the cheese wound in the rough winding, there is a problem that so-called ribbon winding must be avoided. This ribbon winding occurs almost always when a complete bobbin rotation is performed after every double stroke of the thread guide of the swinging device. At that time, a complete reciprocating motion of the thread guide is called a double stroke.

In ribbon winding, the reversal point of the yarn of the currently formed winding essentially lies above the reversal point of the preceding stroke, and thus the successive windings. The layers meander directly above and below.

Ribbon winding hinders the rewinding of the bobbin. In addition, the ribbon winding causes vibration of the winder during the winding process, thus causing a quiet abutment of the friction roller of the friction drive mechanism normally used in the winder, and a quiet silence of the friction roller on the bobbin. This causes abutment and slip between the friction roller and the bobbin, and damage to the bobbin. Therefore, ribbon winding should be avoided when winding smooth yarns, such as chemical fibers.

Various methods are known for avoiding ribbon winding, that is, for eliminating so-called ribbon winding.
For example, from DE 21 65 045 B2, the ribbon winding is performed by switching the swirling speed of the thread guide just before an integer ratio of the number of revolutions of the bobbin to the number of double strokes per unit time is reached. There is a known method of solving the problem.

The disadvantage of this method, however, is that it is only used in the case of individually driven winding units, the significance being that of the ratio of the number of revolutions per unit time to the integer number of double strokes formed. Each winding unit must be provided with one or more sensors for detection and a controller for controlling the swing speed. Therefore, this method is rarely used. This is because, for example, textile machines or spinning machines usually have a large number of winding units which cannot be driven individually. Moreover, this method is very expensive to apply.

In another method for avoiding ribbon winding, the swaying speed of the thread guide is cyclically in the form of a sweep line, usually between speed and maximum speed, according to a predetermined functional dependence. Attempts to change. However, in practice, it has been found that it is not possible to avoid ribbon winding effectively by this method (see German Patent Publication No. 28 55 616).

[0008] Therefore, in this German Patent Publication No. 28 55 616, the above method is improved and developed so that the aperiodic change of the swaying speed is represented in the form of an aperiodic sweep line. Methods of avoiding winding have been proposed. For this purpose, in particular, the acceleration-related or delay-related values of the swaying movement are not changed aperiodically, so that the time interval between the changes from acceleration to delay or vice versa is kept constant. . In this case, the aperiodic sweep line results from the amplitude modulation of the periodic sweep function.

Another possibility is to change the acceleration and delay values aperiodically, but as soon as the twiring speed reaches a predetermined maximum or minimum value, in any case switch immediately without depending on time. Is proposed to do. In this method, the aperiodic sweep line is generated by frequency modulation of the periodic sweep line.

This method, in particular for avoiding ribbon winding, is such that the absolute values of the acceleration and the delay of the swinging motion are kept constant and that the switching between the acceleration and the delay or vice versa. Is done in such a way that the maximum and minimum values are changed aperiodically each time.

If the acceleration and delay values of the swing motion are likewise constant, another possibility is to periodically change the time interval between the switching points, in which case the maximum and minimum swing speed values are It is proposed that the switching be exceptionally time-independent when is reached.

[0012] However, experience has shown the drawbacks of the method for determining aperiodic sweep lines described in German Patent Publication No. 28 55 616.
Even if equal accelerations and delays are made, the same swing speed can be reached relatively often. This reduces the intended effect of unwinding the ribbon, so that in any case optimum winding formation is not guaranteed.

[0013]

The problem underlying the present invention is that the abovementioned disadvantages are avoided and that, with a small outlay, optimum winding formation is ensured with sufficient avoidance of ribbon winding. To provide a method and apparatus for winding.

[0014]

SUMMARY OF THE INVENTION The above problems are solved by the present invention by the features set forth in claims 1 and 13 of the claims.

Switching from acceleration to delay or vice versa is performed randomly, the maximum and minimum values of the switching of the swing speed are randomly changed, and between this reversal point (Umkehrpunkt) within predetermined limits. Due to random changes in time,
When acceleration and delay are equal, it is unlikely that equal swing speeds will form. Therefore, the formation of an integer ratio of the number of bobbin revolutions to the number of double strokes per unit time-where ribbon winding occurs-is even more unlikely in machines with a large number of winding devices. This is because, unlike the known method, the method according to the present invention forms an aperiodic sweep line, and changes the maximum value and the minimum value of the swing speed in this sweep line and the time interval between the reversal points. This is because the values of acceleration and delay of the swing speed always change statistically by random selection of.

According to another configuration of the present invention, different value ranges are used to determine the time interval between the inversion points of the sweep line, the time interval between the minimum and maximum values of the sweep line or the time interval between the maximum and minimum values of the sweep line. Applied regardless of whether is detected. Values are randomly selected from these value regions in an alternating manner to determine aperiodic sweep lines.

The above-mentioned configuration has the advantage that different value ranges can be obtained for the acceleration and delay values of the swing motion. These value ranges differ with respect to their width and / or their position, which avoids with a greater probability that a constant swing speed is often formed when the acceleration and the delay are equal.

In a particularly advantageous construction of the method according to the invention, the value range for the maximum and minimum values of the swing speed and the value range for the time interval between these inversion points of the sweep line are each one. It is composed of a constant average value and a value range overlapped with this average value. As a result, the effort in randomly determining the reversal point of the sweep line is, for example, one different average value for each of the maximum and minimum values of the swaying speed and the only value that is overlapped with this average value. It is reduced by composing from the region. This method, of course, helps to reduce the time and effort required for calculation when determining the time limit, even when the value range regarding the time limit between the maximum and the minimum or between the minimum and the maximum of the sweep line is different.

According to another configuration of the method according to the invention, the dependence between the value ranges for the time limits between the reversal points on the one hand and for the maximum and minimum values of the swaying speed on the other hand is also time-dependent. It is generated that each value obtained from the value range has its own value range relating to the maximum and minimum speeds of the swing motion. As a result, a two-dimensional value region having an aperiodic shape (assuming Cartesian coordinates) is formed.

In a superior construction of the method according to the invention, the non-periodic sweep line is first determined on the basis of the periodic sweep line, the time intervals between the reversal points being random at each time point. Is selected equal to the average of the value ranges for the random determination, and the maximum and minimum values of the swing speed are selected equal to the average of the value range for the random determination of this value. In this case, the value range is a value range that changes symmetrically with respect to zero. However, it is of course also possible to use an arbitrary value instead of the mean value, and to consider further transitions of the reversal point of the periodic sweep line into a value range that is not symmetrical about zero. In this configuration of the method according to the invention,
Each of the inversion points of the periodic sweep line belongs to a two-dimensional value area formed from the value areas that are overlapped with the average value. At that time, the inversion point of the aperiodic sweep line is determined by randomly selecting a coordinate pair from this two-dimensional value region, and at this coordinate (all positive and negative signs (Vorzeiche
Considering n)) the corresponding average values are added.

In this case, in practice, the next reversal point of the aperiodic sweep line must be determined before the next reversal point of the swing motion is reached. Then, from the two coordinate pairs of the reversal point, for example, a particularly constant acceleration of the swing motion required to reach the maximum value or the minimum value of the swing speed of the next reversal point within a predetermined time period is determined. To be done.

In order to implement the method according to the invention in a particularly digital manner, the two-dimensional value domain of each periodic sweep line is divided into a predetermined number of sub-regions, each sub-region being non-periodic. A non-consecutive pair of values for the corresponding inversion point of the sweep line is assigned.

On the one hand in order to utilize the available value ranges for the maximum and minimum values, and on the other hand to utilize the maximum and minimum or the time interval between minimum and maximum, two-dimensional values with the same probability in particular. One of the partial areas of the area is randomly selected.

In a preferred embodiment of the method according to the invention, the peripheral speed of the bobbin is adapted to the current twilling speed so that the length of the yarn wound per unit time is constant. In this way, disadvantageous false drafts are avoided, especially when winding synthetic fibers.

In order to randomly detect the reversal points of the aperiodic sweep line in order to determine the peripheral speed, the two-dimensional value range is taken into consideration by taking into account the corresponding mean value. Used in a two-dimensional value domain to determine the corresponding inversion point of the curve for. Of course, in this use, there is no change in the time between inversion points. This is because the change in the bobbin peripheral speed must be synchronized with the change in the speed of the swing motion.

In order to determine the bobbin circumferential speed between the reversing points for reducing the trouble of removing the ribbon winding, the trouble of adjusting, or the trouble of controlling, the change in the speed of the bobbing motion and the bobbin are roughly determined. It is based on a proportional relationship between changes in circumferential velocity-an angle function-which must be considered if it is taken strictly in this dependence-.

A characteristic of the device for carrying out the method according to the invention described above is that the winding device comprises a control unit, which controls the peripheral speeds of the thread guide and the bobbin by the method described above. It is configured to do.

Hereinafter, the present invention will be described in detail with reference to the embodiments illustrated in the accompanying drawings.

[0029]

1 shows the components of a winding device 1 which are important for understanding the invention, for example the components for the spinning position of a draw winder for producing synthetic yarns. The yarn 2 is supplied to the winding device 1 at a constant speed. The yarn 2 is fed-as shown in FIG. 1-for example via a godet roller 3 driven at a constant number of revolutions, by a feed roller 3a or by another feed mechanism.

A twill drive mechanism 5 driven by a motor 4 capable of converting the number of revolutions is provided with a reciprocating thread guide 6, and this twill drive mechanism makes the yarn 2 constant or variable in the twill swing width. The cheese roll 7 is guided over its entire length. At that time, the thread guide 6 is particularly parallel to the axis of the cheese roll 7. The cheese roll 7 is rotated along its peripheral surface by a friction roller 9 driven by a motor 8 capable of converting the rotation speed. At this time, this drive by the friction roller is constant without the peripheral speed of the cheese roll depending on the diameter of the cheese roll, that is, the number of rolls, and for controlling or adjusting the drive mechanism for this purpose. It has the advantage that it does not require time and effort.

The drive motors 4 and 8 consist of a central control unit 9
This control unit controls both drive motors 4, 8 in the manner according to the invention as described below.

In order to avoid the formation of ribbon winding, the central control unit 9 causes the aperiodic sweep line 10 (FIG. 1) with respect to the swing speed Vc-the movement of the thread guide 6 according to this swing speed being carried out. 2)). At this time, the swing speed Vc is defined as the number of reciprocating movements (double stroke) of the sled guide 6.

In order to determine the aperiodic sweep line 10 according to the present invention, the maximum value of the swing speed is 10a at the maximum of the aperiodic sweep line 10 and the minimum value of the swing speed is at the minimum 10b. Changed, and the time limit between the maximum 10a of the sweep line and the subsequent minimum 10b or the minimum 10b of the sweep line
And the time period between the maximum and the subsequent 10a is randomly changed within a predetermined limit. These inversion points 10 of the sweep line 10
Between a and 10b, the acceleration and delay of the swing speed Vc must be kept particularly constant.

A unique value region is provided for each of the values to be determined, in order to randomly determine the maximum and minimum swing speeds and to randomly determine the time interval between the inversion points of the sweep line. Each value is randomly selected from this value area. That is, likewise when determining the time interval between the minimum 10b and the maximum 10a, or between the maximum 10a and the minimum 10b, respectively, separate value ranges are likewise applied for the maximum and minimum values of the velocity.

Regarding the time limit between the minimum 10b of the sweep line 10 and the maximum 10a following it, or the maximum 1 of the sweep line 10
By applying a different value range for the time period between 0a and the subsequent minimum 10b, the probability of ribbon winding occurrence is significantly reduced. This is because by randomly determining the maximum or minimum value of the swaying speed and the corresponding time interval between the reversal points, the acceleration and delay of the swaying movement are also continuously and statistically changed. In other words, a constant (especially averaged) value for the swing speed Vc is reached between each of the sections of the sweep line 10 between the minimum 10b and the maximum 10a or vice versa. But these points pass with great probability, each with one other acceleration and delay. As a result, no ribbon winding is observed.

These inversion points 10a, 10 of the sweep line 10
The random selection of the coordinates of b can be done in various ways. Two of these methods will be described below. Of course, the invention is not limited to these two methods.

First, as described above, the maximum swing speed, the minimum swing speed, one minimum and the maximum time following each, and one maximum and the minimum time following each, respectively. We start by preparing four different value fields for random selection.

Of course, these value ranges apply corresponding value ranges corresponding to one corresponding value, and the values randomly selected from this value range for the above parameters correspond to the change of the value range. It is also possible to form it so that it may be added to each value (considering both positive and negative signs). In particular, the conversion of the value range is carried out such that the original value range is shifted symmetrically with respect to zero, the value of this transition being equal to the respective mean value.

By such a method, in some cases,
The above four value areas are converted into only two value areas, that is, between the value area for determining the maximum and minimum values of the swing speed, and between the minimum value and the following maximum value or the opposite stroke. It is possible to reduce the value range for the determination of the time limit.
Of course, then, different constant value areas are correctly added to the values randomly selected from these value areas. However, the premise of this possibility to save effort is that there is a constant (or standardized) difference between the limits of the two merged value ranges. This generally has no adverse consequences.

In the two methods described below, first, the maximum value and the minimum value of the swaying speed for the inversion point of the aperiodic sweep line 10 to be determined are selected from the value range, and depending on the case, Is added with a constant value. For this purpose, the central control unit 9 must know whether the reversal point to be determined is a maximum 10a or a minimum 10b. However, since the minimum 10b and the maximum 1a of the aperiodic sweep line 10 alternate, the central control unit 9 has to select the desired maximum or minimum value only from the other value range in each case, or If only one value field is applied, then another constant value must be added to the randomly selected value.

Random timed selection is also the same for the two methods described below to detect aperiodic sweep lines. These methods differ in the temporal parallelism of randomly selected values for the time period between inversion points.

The possibility for a chain of time periods is that they are easily paralleled. That is, the ending point of the preceding time period coincides with the starting point of the next randomly selected time period. Another possibility for randomly selected timed chains is shown in FIG. In this case, the value range in which the time period is randomly selected is represented in such a manner that the value range correspondingly symmetrically transitioning to zero is superposed on a certain average value.
Randomly selected time chain-also this is "a constant mean value + positive and negative sign correctly randomly selected value"
Exists in the form of so that the closest time period is not added to the end of the preceding time period, but to the end of the average value of this preceding time period.

Therefore, the whole method for determining the aperiodic sweep line 10 can be stated as follows. That is, the starting point is a periodic sweep line 11, and the inversion points 11a and 11b of this sweep line are determined by the coordinates of a constant average value of the value range which changes symmetrically with respect to zero in each case. The maximum and the minimum of this periodic sweep line are displaced in time by a value randomly selected from the value range that has changed in the first stage.

Subsequently, these reversal points of the already aperiodic sweep line are now plotted on the ordinate so that the value of the swing speed Vc corresponds to a value randomly chosen for these reversal points 10a, 10b. Is changed in the direction of.

At this time, when the value area relating to the random selection of the maximum value and the minimum value of the inversion points 10a and 10b also exists in the form of "a value area which changes symmetrically with respect to a constant average value + zero", This is the diagram shown in FIG. Symmetric sweep line 1
The two-dimensional value areas 12 belong to the maximum 11a and the minimum 11b of 1 respectively. This value range is formed in particular in the form of a rectangle, in which case the spread of this value range in the abscissa direction lies in the symmetrically zero-shifted value range for the maximum and minimum random choices, and in the ordinate direction. In particular, the spread at corresponds to a value range that is symmetrically shifted with respect to zero for the random selection of the maximum and minimum values for the swing speed.

Of course, these methods can be modified so that other shapes can be applied instead of a rectangular two-dimensional value domain. However, in this case, the dependence of the spread of the value range in the ordinate direction, that is, the spread of the value range for determining the maximum and minimum swing speeds on the value in the value range in the time axis direction is established.

In the digital realization of this method, the two-dimensional value area, which is formed in particular in the form of a rectangle, is divided into individual sub-areas, with each sub-area being associated with a maximum and a minimum twirl speed. A non-continuous value and a non-continuous value for the time interval of the above-mentioned inversion point from the temporal position of the preceding inversion point of the periodic sweep line are assigned. Random selection of the coordinates of the reversal points of the aperiodic sweep line is carried out in a similar manner by randomizing the non-continuous values of the corresponding reversal points of the periodic sweep line in the abscissa and ordinate directions. It is done by various choices.

Another possibility for randomly determining the position of these inversion points is that the individual sub-regions of the two-dimensional value domain are numbered and one of these many numbers is randomized. It is to take out. The corresponding coordinate pair for the inversion point can be inferred, for example, from the corresponding sequence table.

Since the length of the yarn wound per one stroke or double stroke changes due to the change in the twill swing speed of the thread guide, in order to avoid an illegal draft and to ensure a satisfactory winding body formation, The peripheral speed of the cheese roll 7 must be adjusted appropriately. At that time, essentially, mutual dependence is generated between the swing speed Vc and the required bobbin peripheral speed Vu.

FIG. 3 is based on the method shown in FIG. 2 for determining an aperiodic sweep line, the time-dependent peripheral velocity of the cheese roll 7 and the number of revolutions of the friction roller 9 proportional thereto. Shows the possibility to decide. At this time, the curve 12 relating to the peripheral velocity Vu indicates that the peripheral velocity V corresponding to each of the maximum value and the minimum value relating to the swing speed Vc
The value for u is determined as calculated. At this time, in order to reduce the trouble of unwinding the ribbon, each two-dimensional value area is converted into a corresponding value area regarding the peripheral speed Vu and stored in the control unit 9. This storage shortens the two-dimensional value area in the ordinate. This is because the peripheral speed Vu must change in synchronization with the swing speed Vc.

In order to determine the value relating to the peripheral velocity Vu between these transferred values of the reversal point, the angle function parameter must be taken into account in the following relation, if strictly speaking, but the peripheral velocity is approximated. It is presumed that the proportional dependence of the change of the sway on the change of the swing speed is proportional. However, in practice, it has been found that this approximation is sufficient for accuracy.

Therefore, when the acceleration and delay of the swing speed Vc between the inversion points of the aperiodic sweep line are constant, the peripheral velocity between the inversion points of the aperiodic sweep line 12 regarding the peripheral velocity Vu is also the same. Constant acceleration and delay of

[0053]

The winding device according to the invention avoids the above-mentioned disadvantages of the conventional winding devices and guarantees optimum winding formation without the need for ribbon winding at a small expense. It

[Brief description of drawings]

1 shows an embodiment of the device according to the invention for winding a yarn. FIG.

2 shows clearly the aperiodic sweep line and the peripheral velocity required for the bobbin determined thereby according to a preferred embodiment of the method according to the invention.

FIG. 3 clearly shows the aperiodic sweep line and the peripheral velocity required for the bobbin determined thereby according to a preferred embodiment of the method according to the invention.

[Explanation of symbols]

 1 Winding device 2 Thread 3 Godet roller 4 Motor 5 Twill drive mechanism 6 Thread guide 7 Cheese winding 8 Motor 9 Friction roller 10 Sweep line 10a Max 10b Min 11 Sweep line 11a Max 11b Min 12 Sweep line

Claims (13)

[Claims] 01. A method for winding a yarn, comprising: a) feeding the yarn (2) at a constant rate, b) winding into a coarse cheese roll, c) avoiding ribbon winding In a method for winding a yarn in a manner in which a twirl speed (aperiodic sweep line) is aperiodically changed, d) acceleration of a sweep line (10) to delay or its (reversal point 10a) , 10b) changing the maximum and minimum values of the swing speed (Vc) at which the respective switching to the opposite process is performed, e) the time interval between the inversion points (10a, 10b) of the sweep line (10) For winding a yarn characterized by randomly varying the 2. Method according to claim 1, characterized in that the value of the acceleration or the delay of the swing motion is essentially constant. 03. To determine a time period between each minimum (10b) and maximum (10a) of each sweep line (10), and between each maximum (10a) and minimum (10b) of each sweep line. Method according to claim 1 or 2, characterized in that equal or different value ranges are used to determine the time period and the time periods are alternated and randomly selected from these value ranges. 04. Applying different value ranges to determine the maximum and minimum values of the swing speed (Vc),
The method according to any one of claims 1 to 3, wherein the maximum value and the minimum value are alternately selected from these value regions and selected at random. 05. One constant average value and one random value range for the maximum value and minimum value of the swing speed (Vc) and / or for the time period between the inversion points of the sweep line. 5. A method according to claim 3 or 4, characterized in that the composition comprises a value range which is overlapped with the average value and symmetrically shifts to zero for determining. 06: The value region relating to the time limit and the value region relating to the maximum value or the minimum value of the swaying speed (Vc) are mutually dependent so as to relate to the maximum value or the minimum value of the swaying velocity (Vc) to each value of the time period. Method according to claim 4 or 5, characterized in that a predetermined limit of the corresponding value range is assigned. 07. A non-periodic sweep line (10) is determined by using a periodic sweep line (11) as a basis, wherein the time intervals between the reversal points (11a, 11b) are determined randomly. Selecting the maximum and minimum values of the swing speed equal to the average value of the value range for the random determination of this value, and this periodic sweep line ( Inversion point (11a, 11b) of 11)
A two-dimensional value area formed from a value area that is symmetrically shifted to zero and is superposed on the average value is assigned to each of the values, and this value area is assigned to the reversal point of the aperiodic sweep line (10) ( 10a, 1
Method according to 5 or 6, characterized in that it is used to determine 0b). 08. Each two-dimensional value region of a periodic sweep line is divided into a predetermined number of sub-regions, and the corresponding inversion point (10a) of the aperiodic sweep line (10) is divided into each sub-region. , 1
Method according to claim 7, characterized in that the non-contiguous value pairs for determining 0b) are assigned. 9. Method according to claim 8, characterized in that the sub-regions are selected with the same probability. 10. To determine a non-continuous pair of values, first one of the non-continuous values for the time period, and subsequently one of the non-continuous values for the maximum and minimum swing speed (Vc). The method according to claim 8 or 9, characterized in that, or one of the opposite values of these values is randomly selected from the value range that symmetrically changes with respect to zero. 11. The bobbin (7) is adapted so that its peripheral speed (Vu) corresponds to the twilling speed (Vc) at that time so that the length of the yarn wound per unit time is constant. The method according to any one of claims 1 to 10, wherein: 12. In order to determine a required bobbin peripheral velocity (Vu), a value region or a two-dimensional value region concerning the maximum value and the minimum value of the swing speed (Vc) is considered in consideration of a corresponding average value. Then, the functional dependence required to reach a certain winding speed is applied to form a corresponding value range for the required peripheral speed (Vu), where twirl movements can occur. In order to assign the required value of the bobbin peripheral speed to each of the reversal points, and to determine the bobbin peripheral speed between the two reversal points, the change of the swing speed (Vc) and the direction of the bobbin peripheral speed (Vu) are determined. The method according to claim 11, characterized by applying a cyclic dependency between the opposite required changes in. 13. Device for winding a yarn, the winding device comprising a control unit (9), said control unit comprising movement of the thread guide (6) and peripheral speed (Vu) of the bobbin (7). An apparatus for winding a yarn, characterized in that it is configured to control and according to the above method.