DE10158975A1 - Cruciform thread to bobbin winding process matches bobbin peripheral speed to transverse thread guide movement - Google Patents

Abstract

In a bobbin cross-winding process, the bobbin turns at a pre-determined peripheral speed (VU) and the thread is guided back and forth. The speed of bobbin peripheral rotation is varied in accordance with changes in the thread back and forth speed (VG). The bobbin thread peripheral speed is altered as required to maintain essentially constant speed (VF) of the incoming thread and a constant feed angle alpha of the thread to the existing winding. The bobbin peripheral speed (VU) is derived from an assessment factor B, where B = (1 + (VG/VU)(/ (1 + (VGneu/VU)( , and VGneu is the new transverse speed.

Description

The invention relates to a method for winding a thread into one Cross-wound bobbin according to the preamble of claim 1.

When winding a synthetic thread into a package, the thread becomes before being placed on the package by means of a thread guide parallel to the package back and forth to intersecting deposits of the thread on the circumference of the Get coil. The cheese is driven at a rotational frequency, to maintain a predetermined peripheral speed of the package is reduced with increasing coil diameter. Through this Changes in the rotational frequency of the cheese occur conditions in which one Double stroke frequency of the thread guide a certain multiple of Rotational frequency of the cheese is. A double stroke is a complete one Back and forth movement of the thread guide before depositing the package. The ratio of the rotational frequency of the cheese to the double stroke frequency the thread guide is generally referred to as the crossover ratio K. In the cases where the crossing ratio K is an integer or is an integer fraction, the problem of so-called image windings occurs. The image windings, which are also called mirrors, lead to one threads lie directly on top of each other and thus become unstable Coil construction. Such image windings must therefore be particularly smooth Threads such as B. man-made fibers can be avoided.

The winding of a thread into a cheese can in principle according to the different types of winding of the wild winding, the Precision winding or the step precision winding. In the wild  The winding takes place at constant circumferential speed of the winding Cheese and at the same time constant double stroke frequency Thread guide. As the rotational frequency of the cheese changes with increasing Coil diameter is constantly changing, thus becoming a constant Change in the crossing ratio occur. Thus inevitably arise Picture windings.

In the case of a precision winding, the coil is built up with a Double stroke frequency of the thread guide, which corresponds to the rotational frequency of the package is directly proportional. This means that with a precision winding Crossing ratio is fixed and constant in the course of the winding travel remains while the double stroke frequency of the thread guide is proportional to Rotation frequency of the cheese decreases. Such a winding process reduces the risk of image winding but with the disadvantage that the Thread with a constant crossing angle is deposited on the package, what again leads to an unfavorable coil structure.

The so-called stepped precision winding or step precision winding differs from the precision winding only in that the Intersection ratio only during specified periods of winding remains constant. The crossing ratio becomes from time period to time period in jumps by suddenly increasing the double stroke frequency of the Thread guide reduced. That means that with the step precision winding Precision winding takes place within each time period or step, where the double stroke frequency of the thread guide is proportional to the Rotation frequency of the cheese decreases. After each time period the Double stroke frequency of the thread guide increases again suddenly, so that a results in a smaller crossing ratio.

There are winding methods for each of the aforementioned types of windings known for which additional measures to avoid  Image windings are suggested. For example, the wild Winding method from EP 0 093 258, EP 0 256 411 and US 5,725,164 known in which the double stroke frequency of the thread guide superimposed receives periodic changes to go through critical winding conditions. The guiding speed of the thread with which the thread is parallel to the package, changed.

It is also known for the winding type step precision winding, which Guiding speed of the thread before running on the package after certain rules to vary to critical intersection ratios run through, as for example in the publications EP 0 194 524, EP 0 195 325 or EP 0 578 966.

All methods known in the prior art have in common that for Avoiding image windings the guiding speed of the thread Storage on the package is changed. However, this does not take into account that every change in leadership speed is a change in Thread tension results. Methods are known in principle for which a thread tension measured on the running thread and in Depending on an actual / target comparison a regulation of the Peripheral speed of the package is running. In addition, leaves , as is known from EP 0 664 765, from the regulation of the Circumferential speed of the cheese an adjustment of Make guide speed. In this known method however, only after a change in the thread tension has been determined triggered.

The invention is therefore based on the object of a method for Winding a thread to create a package in which the through the winding of the thread produced fluctuations in the thread tension be avoided.  

This object is achieved by a method with the features according to claim 1 solved.

Further advantageous developments of the invention are in the subclaims Defined 2 to 11.

The inventive method is characterized in that the Disturbance variable which would cause a fluctuation in the thread tension, through a corresponding countermeasure in its negative impact is neutralized. The disturbance variable during winding is the Change the guiding speed of the thread to see that to avoid of image windings can be changed according to predetermined process patterns. each The proposed change in the guide speed is according to the invention Control of the peripheral speed of the package is used. By The peripheral speed of the cheese can be changed immediately influence the thread tension in the starting thread. So that represents The method according to the invention represents a possibility of compensating the Make thread tension changes without making any changes to can act alone.

Since the thread speed with which the thread of the package is running as A characteristic size of the thread tension can be seen in a particularly advantageous method variant according to claim 2 Circumferential speed of the package in relation to the change in Guiding speed of the thread changed such that a predetermined Thread speed remains essentially constant. This ensures that the thread tension remains constant and a very even one Coil structure can be generated. The per unit time on the cheese The amount of thread deposited is due to the constant thread speed essentially constant throughout the winding time. With that  Predicting the stored thread lengths per unit of time or achieved coil diameter per unit of time in a simple manner.

In the event that certain angle of deposit during the change of The guiding speed must be observed, the process variant is according to Claim 3 particularly advantageous. Here, the peripheral speed of the Cross-wound bobbin in relation to the change in the guiding speed of the thread changed such that a predetermined crossing angle when the thread is deposited remains essentially constant.

However, it is also possible, according to another particularly preferred Process variant a preset crossing ratio during the To maintain change.

In another particularly advantageous method variant, the control the peripheral speed from the change in the guide speed Evaluation factor determined. This evaluation factor is then used as a measure of the adjustable change of the peripheral speed used. So that exists Ability to predict changes in peripheral speed, so that exact control is possible during the entire winding time. Every change in the management speed is in one Evaluation factor implemented so that in each case a proportional change in the Peripheral speed is executable.

The weighting factor B is preferably derived from the equation

B = [1 + (v _G / v _U ) ² ] / [1 + (v _Gneu / v _U ) ² ]

calculated. The new peripheral speed to be set then results from the relationship V _Uneu = B * v _U , the guide speed being designated as v _G , the changed guide speed as v _Gneu , the peripheral speed as v _U and the peripheral speed to be set as v _Uneu .

To those resulting from the upstream processes Eliminating thread tension changes is the process variant according to Claim 8 particularly advantageously applicable. This is a superimposed Control of the peripheral speed depending on a thread tension provided, the thread tension measured on the running thread and a Actual / target comparison is supplied. Depending on a generated one Differential signal can then be a superimposed change in Set peripheral speed.

The method according to the invention can be used for any type of winding. So it is possible that during an entire winding time for winding the Cheese has a basic setting in which the double stroke frequency of Thread guide is kept proportional to the rotational frequency of the package.

However, there could also be a basic setting in which the Double stroke frequency of the thread guide independent of the rotational frequency of the Cheese is kept constant.

However, it is also possible to make a basic setting for which at times the double stroke frequency of the thread guide is proportional to that Rotational frequency of the cheese is held and at which the Double stroke frequency of the thread guide independent of the rotational frequency of the Cheese is kept constant.

Further advantages and possible uses of the invention are now based on the description of an embodiment with reference to the figures explained in detail.  

Show it:

Figure 1 shows schematically a winding device for winding a thread into a package.

Figure 2 shows the vector sum of a peripheral speed of the package and a guide speed of the thread.

Fig. 3 is a diagram showing the waveform of the command speed and the peripheral speed;

Fig. 4 is a diagram showing the course of the guide speed, the peripheral speed and the thread speed.

In Fig. 1, a winding device for winding a thread to a package is shown schematically. The winding device comprises a spindle 4 which is connected to a drive 5 . A sleeve 3 is clamped on the circumference of the spindle 4 . A cheese 2 is wound on the sleeve 3 . The thread 1 is guided in an oscillating manner essentially parallel to the package 2 by a thread guide 6 . For this purpose, the thread guide 6 is coupled to a drive 7 . The drives 5 and 7 are controlled via the control device 8 .

In the winding device shown in FIG. 1, the control device has 8 parameters for winding, such as the type of winding, winding time, mirror interference method, etc., stored. Depending on the stored data and the control program, drives 5 and 7 are controlled. The cheese 2 can be driven at a peripheral speed v _U. The thread guide 6 can be moved back and forth at a guide speed v _G. This results in a thread speed v _F , which can be determined as a vector sum from the peripheral speed v _U and the guide speed v _G. For this purpose, the vector sum is shown schematically in FIG. 2. The angle formed by the vector sum is equal to the crossing angle α, which results when the thread is deposited on the package. From the graphic representation of the vector sum it can now be derived directly that any change in the guide speed v _{G of} the thread must lead directly to a change in the thread speed v _F and thus to a change in the thread tension. This is where the method according to the invention begins, in which the peripheral speed v _{U of} the cheese is controlled as a function of the change in the guide speed v _G. The peripheral speed v _U can now be controlled in such a way that the thread speed v _F remains constant regardless of the change in the guide speed v _G. Here, the crossing angle α, which was set immediately before the change in the guide speed v _G , can also be kept constant. It is also possible to take the pre-change in the guide speed v _G set crossing ratio K into account when controlling the peripheral speed in such a way that the crossing ratio K remains constant. The crossing ratio K results from the ratio of the rotational frequency of the cross-wound bobbin f _S and the double stroke frequency of the thread guide f _C.

Depending on the desired requirements, an evaluation factor B can be determined from the change in the guide speed. This is the relationship

B = [1 + (v _G / v _U ) ² ] / [1 + (v _Gneu / v _U ) ² ]

used. v _G is the leading _speed before the change, and v _{Gneu is} the leading _speed after the change. V _{U is also} the circumferential speed before the guide speed changes. From this equation, the evaluation factor is calculated, from which the peripheral speed to be set is determined.

The following applies: v _Uneu = B * v _U.

In Fig. 3 is a diagrammatic representation of the command speed and the peripheral speed is illustrated. Here, for example, a basic setting of the guiding _{speed is} predefined with v _G. This basic setting of the guide speed is maintained during the entire winding time. Superimposed on the basic setting of the guide speed v _G , there is a change in the guide speed, which alternately provides for the guide speed to be raised and lowered. This course is marked in the diagram with v _eff and represents the effective guiding speed of the thread. This effective guiding _speed can now be applied as the changed guiding _speed V _Gneu , so that for each corresponding changed value of the guiding speed a changed value of the peripheral speed V _Uneu is predictable. This is shown in the lower diagram in Figure. 3 shows the course of the peripheral speed v _{Uneu of} the _cheese . It can be seen that any increase in the guide speed results in a reduction in the peripheral speed. The resulting changes in thread tension cancel each other out, so that the thread tension remains constant during winding.

In the event that the changes in the guide speed v _{G are carried out} in very short time intervals, a resulting basic setting can be calculated from the effective guide _speed v _eff and the basic setting of the guide speed v _G. The unchanged guide speed v _{G is} modified with the evaluation factor B. And there is the course of the corrected basic _setting V _GKor .

The course of the peripheral speed of the cheese v _{U is} shown in the middle diagram, the changes in the peripheral speed in this case being proportional to the changes in the basic _{setting of} the guide _speed V _GKor . In addition to the thread speed, a constant crossing angle can advantageously be achieved when the thread is deposited on the package. The course of the thread speed v _{F is} shown in the lower diagram in FIG. 4. The thread speed v _F remains constant. In this respect, the impediment to the guiding speed to avoid image windings is advantageously compensated for.

The method according to the invention can be easily applied with a superimposed one Control of the peripheral speed depending on a thread tension complete. For this purpose, before the thread runs onto the cheese Thread tension preferably measured in the thread path in front of the thread guide. The Measured value is fed to the control device and with a setpoint adjusted. In the event that there is a difference, an additional Differential signal generated by the control device to drive the spindle to control accordingly. This can be used in the upstream process striking changes in thread tension are advantageously absorbed, without affecting the winding.

In the winding device shown in FIG. 1, a basic setting of the winding type is preferably predetermined in the control device 8 . As a basic setting, the control device 8 can be given that the double stroke frequency f _{C of} the thread guide, which is determined by the drive 7 , is kept proportional to the rotational frequency f _{S of} the cheese, which is determined by the drive 5 .

A basic setting is also possible in which the double stroke frequency f _{C of} the thread guide is kept constant independently of the rotational frequency f _S of the cheese.

The method can thus be used for both a wild winding and a Precision winding or with a step precision winding without restriction apply.  

LIST OF REFERENCE NUMBERS

1

thread

2

cheese

3

shell

4

spindle

5

drive

6

thread guides

7

drive

8th

control unit
v _U

circumferential speed
v _G

transfer speed
v _F

thread speed
B evaluation factor
K crossing ratio
f _p

rotational frequency
f _C

Doppelhubfrequenz
α crossing angle

Claims (11)

1. A method for winding a thread into a package, in which the package is driven at a predetermined circumferential speed (v _U ), in which the thread is fed back and forth parallel to the package before being deposited on the package at a guide speed (v _G ) and at which the guide speed (v _G ) is changed to avoid image windings (mirrors), characterized in that the peripheral speed (v _U ) of the package is controlled as a function of the change in the guide speed (v _G ) of the thread. 2. The method according to claim 1, characterized in that the peripheral speed (v _U ) of the package in relation to the change in the guide speed (v _G ) of the thread is changed such that a predetermined thread speed (v _F ) remains substantially constant. 3. The method according to claim 1 or 2, characterized in that the peripheral speed (v _U ) of the package in relation to the change in the guide speed (v _G ) of the thread is changed such that a preset crossing angle (α) when depositing the thread substantially remains constant. 4. The method according to any one of claims 1 to 3, characterized in that the peripheral speed (v _U ) of the cheese in relation to the change in the guide speed (v _G ) of the thread is changed such that a preset crossing ratio (K) from a rotational frequency ( f _S ) of the package to a double stroke frequency (f _C ) of the thread guide (K = f _S / f _C ) remains essentially constant. 5. The method according to any one of claims 1 to 4, characterized in that to control the peripheral speed (v _U ) from the change in the guide speed (v _G ) an evaluation factor is determined, which is a measure of the adjustable change in the peripheral speed (v _U ) represents. 6. The method according to claim 5, characterized in that the evaluation factor B is determined using the following relationship:
B = [1 + (v _G / v _U ) ² ] / [1 + (v _Gneu / v _U ) ² ] 7. The method according to claim 5 or 6, characterized in that the peripheral speed (V _Uneu ) of the _{package is set} to a value increased by the evaluation _factor (B * v _U ). 8. The method according to any one of the preceding claims, characterized in that a superimposed control of the peripheral speed (v _U ) is provided as a function of a thread tension, the thread tension measured on the running thread and an actual-target comparison is supplied. 9. The method according to any one of the preceding claims, characterized in that there is a basic setting during an entire winding time for winding the package, in which the double stroke frequency (f _C ) of the thread guide is kept proportional to the rotational frequency (f _S ) of the package. 10. The method according to any one of claims 1 to 8, characterized in that there is a basic setting during an entire winding time for winding the package, in which the double stroke frequency (f _C ) of the thread guide is kept constant independently of the rotational frequency (f _S ) of the package , 11. The method according to any one of claims 1 to 8, characterized in that there is a basic setting during an entire winding time for winding the package, in which at times the double stroke frequency (f _C ) of the thread guide is kept proportional to the rotational frequency (f _S ) of the package and at which the double stroke frequency (f _C ) of the thread guide is kept constant independently of the rotational frequency (f _S ) of the cheese.