EP4122858A1 - Winding machine and method for operating a work site of a winding machine - Google Patents

Abstract

In a method for operating a workstation (2) of a winding machine (1), a yarn (3) is rewound from a cop (22) onto a winding tube (6) by means of a winding device (5), with a yarn balloon (14) being in at least one Width direction is limited by means of a balloon limiting device (18). The balloon limiter (18) comprises at least one balloon limiter (23, 26) with a yarn guide surface (24, 27). A first portion of the yarn (3) on the spinning tube (4) is rewound onto the bobbin tube (6), with a yarn withdrawal force of the yarn (3) and/or a measured variable representing the yarn withdrawal force being recorded. When an increase in the yarn pull-off force is detected, the at least one balloon limiter (23, 26) is moved from a rest position (R) to a working position (A) and then a second part of the yarn (3) is rewound onto the bobbin tube (6). Alternatively, the distance (a1, a2) of a yarn guide surface (24, 27) of the at least one balloon limiter (23,26) to the axis of rotation (25) of the spinning tube (4) is reduced and then a second part of the spinning tube (4) located yarn (3) rewound onto the bobbin tube (6). Alternatively, a second balloon limiter (26) with a second yarn guide surface (27) is transferred from a rest position (R) to a working position (A). For this purpose, a workstation (2) of a winding machine (1) has a detection device (17) for detecting a yarn pull-off force of the yarn (3) and/or a measured variable representing the yarn pull-off force, and a control unit (13).

Description

The present invention relates to a method for operating a work station of a winding machine, in which a yarn is rewound from a cop having a spinning tube onto a bobbin tube by means of a spooling device, with a yarn balloon forming between the spinning tube and the bobbin tube during the rewinding process, at least in one width direction is limited by means of a balloon limiting device. The balloon limiter comprises at least one balloon limiter with a yarn guide surface. A first portion of the yarn on the spinning tube is rewound onto the bobbin tube, with a yarn pull-off force of the yarn and/or a measured variable representing the yarn pull-off force being recorded and the yarn guide surface at least in a working position of the balloon limiter or at least during the rewinding of the first part of the yarn has a certain distance to an axis of rotation of the spinning tube.

The invention further relates to a method for operating a work station of a winding machine, the balloon delimitation device comprising a first balloon delimiter with a first yarn guiding surface, the first yarn guiding surface of the balloon delimiter being at a first distance from an axis of rotation of the spinning tube, at least in one working position, with a first part of the yarn located on the spinning tube is rewound onto the winding tube, the yarn balloon being delimited by means of the first yarn guide surface and a yarn withdrawal force of the yarn and/or a measured variable representing the yarn withdrawal force being recorded.

Finally, the invention relates to a workstation of a winding machine for rewinding a yarn from a cop onto a bobbin tube by means of a bobbin winding device with a balloon limiting device to limit a during the rewinding process between the spinning tube and the Yarn balloons forming the bobbin tube, at least in a width direction, the balloon limiting device containing a first balloon limiter with a first yarn guide surface which, at least in a working position of the first balloon limiter, is a first distance from an axis of rotation of the spinning tube, with at least one detection device for detecting a yarn withdrawal force of the yarn and/or or a measured variable representing the yarn pull-off force and with a control device which is connected to the at least one detection device.

Winding machines are used to rewind yarn from wound spinning tubes, which originate, for example, from a ring spinning machine, onto a winding tube, so that larger bobbins (usually so-called cross-wound bobbins) are formed. This is necessary for the subsequent further processing of the yarn, since the spinning tubes usually contain relatively little yarn. Winding machines have a large number of winding stations, where rewinding processes largely take place independently of one another. During the rewinding process, the yarn from individual spinning tubes is sequentially joined by a splicer into a single continuous yarn. In addition, the rewinding process on the winding machine is used to remove yarn defects from the yarn that have arisen during the spinning process on an upstream spinning machine using a yarn clearer.

During rewinding from the spinning tube to the winding tube, a yarn balloon is formed between the unwinding position at which the spinning tube is located during the rewinding process and a yarn guide downstream of the spinning tube in the direction of yarn travel. This yarn balloon forms due to the centrifugal forces that act on the yarn when the yarn is unwound from the spinning tube. The larger the radius of the yarn balloon during the rewinding process, the greater the yarn tension in the area of the yarn balloon. There are therefore already numerous attempts to influence the yarn balloon or to to keep the yarn tension as low as possible during the rewinding process and thus to minimize the number of yarn breaks or the risk of impairment of the yarn quality.

From the DE 10 2006 052 826 A1 a winding machine with several work stations, each with a balloon limiting device, is known. The balloon limiting device can be adjusted in the vertical direction, so that it can be moved downwards during the winding process, following the unwinding progress of the spinning cop. The balloon limiting device comprises a tube which is continuously tracked in the vertical direction during the winding process in accordance with the position of the bobbin cone in such a way that a radial distance between the tube and the bobbin cone remains almost constant. Furthermore, the balloon limiting device includes a second tube which is tracked in the vertical direction depending on the signals of a yarn tension sensor. A so-called single-thread balloon should reliably set in during the entire school process, even at very high winding speeds. The device is structurally comparatively complex. In addition, depending on the winding state of the bobbin, comparatively high yarn tensions can still occur.

The object of the present invention is therefore to propose a method for operating a work station of a winding machine which enables winding with a winding speed which is as constant as possible. Furthermore, a job of a winding machine should be proposed.

The problem is solved by a method and a work station with the features of the independent patent claims.

In a method for operating a work station of a winding machine, a yarn is rewound from a cop having a spinning tube by means of a winding device onto a bobbin tube, with a forming during the rewinding process between the spinning tube and the bobbin tube Yarn balloon is limited at least in a width direction by means of a balloon limiting device. The balloon limiting device comprises at least one balloon limiter with a yarn guide surface which can be transferred from a rest position to a working position, the yarn guide surface being at a certain distance from an axis of rotation of the spinning tube in the working position of the at least one balloon limiter. In this case, a first part of the yarn located on the spinning tube is rewound onto the winding tube, with a yarn pull-off force of the yarn and/or a measured variable representing the yarn pull-off force being recorded. It is provided that when an increase in the yarn withdrawal force by a predetermined value is detected, the at least one balloon limiter of the balloon limiter device is transferred from the rest position to the working position, and that a second part of the yarn on the spinning tube is then rewound onto the winding tube, with the yarn balloon is limited by the yarn guide surface.

The working position is a position of the balloon limiter that it assumes during rewinding and in which it limits the yarn balloon. On the other hand, the rest position is a position in which the balloon limiter does not limit the yarn balloon. At the same time, the rest position can be a bobbin changing position, which enables the empty spinning bobbin to be exchanged for a fully wound bobbin. However, it is also possible that the balloon limiter can be transferred to a cop changing position that differs from the rest position.

Incidentally, the axis of rotation is the central longitudinal axis of the normally rotationally symmetrical spinning tube. However, the spinning tube does not rotate during the rewinding process.

Likewise, the minimum distance between the yarn guide surface and the axis of rotation is meant by the distance between the yarn guide surface and the axis of rotation. The Garnführungsfläche can be cylindrical, so it has the same distance to the axis of rotation everywhere. However, it can also be polygonal or irregular in shape in some other way. In this case, the term "distance" refers to the smallest distance between the yarn guide surface and the axis of rotation.

In a second method for operating a work station of a winding machine, a first part of the yarn located on the spinning tube is rewound onto the winding tube, with a yarn withdrawal force of the yarn and/or a measured variable representing the yarn withdrawal force being recorded and with the yarn balloon being delimited by means of the yarn guide surface . The yarn guide surface of the at least one balloon limiter is at a specific distance from an axis of rotation of the spinning tube, at least during the rewinding of the first part of the yarn. In this second method, it is proposed that when an increase in the yarn withdrawal force is detected by a predetermined value, the distance between the yarn guide surface and the axis of rotation of the spinning tube is reduced and that a second portion of the yarn on the spinning tube is then rewound onto the bobbin tube, with the Yarn balloon is limited by means of the yarn guide surface at a reduced distance from the axis of rotation.

In a third method, the balloon limiter includes a first balloon limiter having a first yarn guide surface. A first portion of the yarn on the spinning tube is rewound onto the winding tube, the yarn balloon being delimited by the first yarn guide surface and a yarn withdrawal force of the yarn and/or a measured variable representing the yarn withdrawal force being recorded. At least during the rewinding of the first part of the yarn, the first yarn guide surface of the balloon limiter is at a first distance from an axis of rotation of the spinning tube. It is proposed that upon detection of an increase in the yarn withdrawal force by a predetermined value, the first distance between the first yarn guide surface and the axis of rotation of the spinning tube is reduced and that a second part of the Spinning tube located yarn is rewound onto the winding tube, wherein the yarn balloon is limited by means of the first yarn guide surface at a reduced distance from the axis of rotation.

Alternatively, it is proposed in this third method that, upon detection of an increase in the yarn withdrawal force by a predetermined value, at least one second balloon limiter of the balloon limiting device with a second yarn guide surface is moved from a rest position, in which it does not limit the yarn balloon, to an operative position, in which it does not limit the yarn balloon limited, is transferred, and that then a second part of the yarn located on the spinning tube is rewound onto the winding tube, the yarn balloon being limited by means of the second yarn guide surface.

For example, when the yarn withdrawal force is measured directly, an increase in the yarn withdrawal force by a predetermined value is detected when the yarn withdrawal force increases by a predetermined absolute or percentage value compared to an initial value. In the case of indirect measurement, for example by evaluating a position of a yarn tensioner, an increase in the yarn pull-off force by a predetermined value can also be detected by the yarn tensioner covering a predetermined distance or reaching a predetermined position. The predetermined value can, for example, be set by an operator on the basis of empirical values and stored in a control device of the winding machine. However, the predetermined value can also be obtained and defined by evaluating previous unwinding processes in a self-learning process by the winding machine, in particular a control device of the winding machine. It is also possible that the winding machine only suggests the predetermined value and it still has to be confirmed by the operator.

What all three methods have in common is that, depending on the yarn pull-off force, a yarn guide surface acts on the yarn or the action of a yarn guide surface on the yarn is intensified. This can be done by moving a balloon limiter from a rest position to a working position or by reducing the distance between a yarn guide surface and the axis of rotation of the spinning tube. The additional or intensified effect of the yarn guide surface therefore only occurs when the increase in yarn withdrawal force requires it. Advantageously, it can initially be wound without a balloon delimitation or with only one yarn guide surface acting on the yarn. By "switching on" or "intensifying" one or more yarn guide surfaces as a function of the thread tension, it is then possible to keep the yarn withdrawal force largely constant over the winding process. As a result, the bobbin tube can be wound with a largely constant winding tension, which means that high-quality bobbins can be produced. This also makes it possible to wind with a largely constant, comparatively high working speed during the entire school process. As a result, a continuous entrainment of the balloon limiting device with the winding state of the cop, as in the prior art, is not necessary.

It is also possible within the scope of the invention for additional yarn guide surfaces or additional balloon limiters to be "switched on" several times during the rewinding process depending on the yarn take-off force and/or for the distance between one or more yarn guide surfaces already acting on the yarn to be reduced several times depending on the yarn take-off force.

A work station of a winding machine for rewinding a yarn from a cop having a spinning tube onto a winding tube by means of a winding device is also proposed. The work station includes a balloon limiter to limit deflection during the rewinding process between the spinning tube and the winding tube forming yarn balloons at least in a width direction, wherein the balloon limiting device includes a first balloon limiter with a first yarn guide surface which is at a first distance from an axis of rotation of the spinning tube at least during rewinding. The work station also has at least one detection device for detecting a yarn pull-off force of the yarn and/or a measured variable representing the yarn pull-off force, as well as a control device which is connected to the at least one detection device. At this job, the controller is in communication with the balloon constraint. Depending on a signal from the at least one detection device, the first balloon limiter of the balloon limiter can be transferred from a rest position, in which it does not limit the yarn balloon, to an operative position, in which it limits the yarn balloon.

Alternatively, it is provided in this work station that the first distance between the first yarn guide surface and the axis of rotation of the spinning tube can be reduced as a function of a signal from the detection device.

According to a further embodiment, at this work station it is additionally or alternatively provided for the balloon limiting device to contain at least one second balloon limiter with a second yarn guide surface, which can be transferred from a rest position to a working position as a function of a signal from the at least one detection device.

As already described, depending on the yarn withdrawal force, the action of a yarn guide surface on the yarn can be “switched on” once or several times during the rewinding process in such a work station in order to keep the yarn withdrawal force largely constant throughout the winding process. Such a work station also makes it possible in an advantageous manner to wind at a constant working speed. Since a continuous tracking of the balloon limiting device with the winding state of the cop is not required, the work station can hereby be designed in a structurally simple and cost-effective manner.

In the method and the device according to the third embodiment, it is advantageous if the second yarn guide surface has a second distance from the axis of rotation of the spinning tube in the working position of the second balloon limiter, which distance is less than the first distance. The bobbins coming from the ring spinning machine are usually unwound in stages so that the spinning tube is gradually freed from the yarn and laid bare from top to bottom. The yarn balloon therefore becomes larger and larger during the winding process. If the second yarn guide surface is at a smaller distance from the axis of rotation of the spinning tube than the first, the yarn balloon can advantageously be narrowed more with the second yarn guide surface than with the first yarn guide surface.

It is also advantageous if, in order to detect the increase in the yarn withdrawal force by a predetermined value, a limit value for the yarn withdrawal force and/or the measured variable representing the yarn withdrawal force is specified and if the limit value is exceeded, the respective balloon limiter is transferred to its working position (A) and/or the distance between the respective yarn guide surfaces is reduced. The limit value can, for example, be an absolute value of the measured yarn pull-off force. If, on the other hand, the path of a yarn tensioning element is recorded as a measured variable representing the yarn withdrawal force, the limit value can also be defined by a specific position of the yarn tensioning element.

It is also advantageous if, in order to detect the increase in the yarn withdrawal force by a predetermined value, a permissible fluctuation range of the yarn withdrawal force and/or the measured variable representing the yarn withdrawal force is defined and if the fluctuation range is exceeded, the balloon limiter is transferred to its working position and/or the distance is reduced. The range of variation can be an allowable deviation of the yarn pull-off force from a previous measured value. If the current measured value leaves this specified tolerance range by the previous measured values, the respective balloon limiter can be transferred to its working position or the distance between the respective yarn guide surface can be reduced.

Furthermore, it is advantageous if the yarn pull-off force is detected by means of a tensile force sensor or, at the work site, the at least one detection device is a tensile force sensor. Such a tensile force sensor is usually already present at the work site, for example in order to control a yarn tensioner depending on the yarn withdrawal force. This can then advantageously also be used to trigger the switching on of the action of a yarn guide surface.

However, it is also advantageous if a position and/or an adjustment path of a tensioning element of a yarn tensioner is recorded as the measured variable representing the yarn withdrawal force. The twine tensioner is usually controlled or regulated depending on the tensile force, i.e. it is opened further when the twine pull-off force increases and it is closed further when the twine pull-off force decreases. The position or the adjustment path covered by the tensioning element of the twine tensioner is therefore a measured variable that represents the twine pull-off force, at least as long as the twine tensioner has not yet reached its end position, and can be used to trigger the activation of a twine guide surface.

Accordingly, it is advantageous if the position of the tensioning element is detected by means of a proximity switch, in particular an optical sensor. It is also advantageous at the workplace if the at least one detection device is a proximity switch, in particular an optical sensor. Alternatively, of course, inductive, capacitive, magnetic or other proximity switches are also possible.

Alternatively, it is advantageous at the work site if the adjustment path of the tensioning element is recorded by means of a path sensor.

According to an alternative embodiment of the method, it is advantageous if the adjustment path of the tensioning element is detected by evaluating a manipulated variable and/or measuring a load variable of a drive of the yarn tensioner, in particular of the tensioning element. For example, a step number of a stepper motor could be detected when the yarn tensioner is moved by means of a stepper motor. Likewise, the adjustment path could also be determined from currents, voltages or other load variables of the drive of the yarn tensioner. In this case, at the workplace, the control of the drive represents the at least one detection device.

Furthermore, it is advantageous if the first balloon limiter and/or the at least one second balloon limiter is a balloon constriction ring. This does not necessarily have to be circular, but can also have a polygonal or other shape, including an irregular shape. Likewise, the first and/or the second balloon limiter could also be tubular structures. The balloon limiter or limiters can be completely closed or have an opening. The balloon limiter or limiters can also be designed to be divisible.

There are advantages if the first and/or the at least one second balloon limiter has at least two limiter elements which can be moved from a first position into a second position. For example, the delimiting elements can assume the first position when the balloon delimiter is in a rest position and the second position when it is in a working position. It is also possible that the limiting elements assume the first position in order to form the yarn guide surface at the first distance from the axis of rotation of the spinning tube and that they assume the second position in order to form the yarn guide surface at the second distance to form the axis of rotation. More than two delimiting elements are also conceivable, which can form yarn guide surfaces with different diameters in the manner of a screen.

Furthermore, there are advantages if the first and/or the at least one second balloon limiter can be transferred into a cop changing position. In this case, the bobbin changing position is different from the rest position. However, it is also possible for the idle position to represent the bobbin changing position at the same time. In principle, the transfer of the first or second balloon limiter into the cop changing position is possible in various ways. It is conceivable, for example, to open divisible balloon constriction rings so far that the cop can be removed. Alternatively, the balloon limiter or the entire balloon limiter can be pivoted or moved linearly in order to be transferred from the working position or the rest position to the cop changing position.

It is advantageous, for example, if the work station has a drive device with the aid of which the first balloon limiter and/or the second balloon limiter can be moved along a guide in the direction of the axis of rotation of the spinning tube. For example, the balloon limiters can be transferred from a rest position or a bobbin changing position above the spinning tube to a working position at the level of the spinning tube.

In the case of a balloon delimitation device with two balloon delimiters, it is particularly advantageous if the first balloon delimiter and the second balloon delimiter are movably mounted on the guide via a common carrier. As a result, both balloon limiters can be transferred together, for example, to a cop changing position above the cop. Likewise, at least one of the two balloon limiters or also both balloon limiters can be transferred to their working position together.

Figur 1

eine Vorderansicht einer Spulmaschine mit einer Vielzahl nebeneinander angeordneter Arbeitsstellen,

Figur 2

eine Vorderansicht einer Arbeitsstelle einer Spulmaschine mit einem vollständig geschlossenen Garnspanner,

Figur 3

die Arbeitsstelle der Figur 2 mit einem vollständig geöffneten Garnspanner,

Figur 4

eine Detailansicht eines Kops und einer Ballonbegrenzungseinrichtung nach einer ersten Ausführung zu einem ersten Zeitpunkt zu Beginn des Umspulprozesses in einer Vorderansicht,

Figur 5

den Kops und die Ballonbegrenzungseinrichtung der Fig. 4 zu einem zweiten Zeitpunkt während des Umspulprozesses,

Figur 6

den Kops und die Ballonbegrenzungseinrichtung der Fig. 4 zu einem dritten Zeitpunkt während des Umspulprozesses,

Figur 7

eine Detailansicht eines Kops und einer Ballonbegrenzungseinrichtung nach einer zweiten Ausführung zu einem ersten Zeitpunkt zu Beginn des Umspulprozesses in einer Vorderansicht,

Figur 8

den Kops und die Ballonbegrenzungseinrichtung der Fig. 7 zu einem zweiten Zeitpunkt während des Umspulprozesses,

Figur 9

den Kops und die Ballonbegrenzungseinrichtung der Fig. 7 zu einem dritten Zeitpunkt während des Umspulprozesses,

Figur 10

eine Darstellung der Garnabzugskraft während des Spulprozesses sowie eines Grenzwertes für die Garnabzugskraft,

Figur 11

eine Darstellung der Garnabzugskraft während des Spulprozesses sowie eines Schwankungsbereichs der Garnabzugskraft,

Figur 12

eine Detaildarstellung eines Garnspanners sowie das Erfassen des Verstellwegs des Garnspanners in einer Vorderansicht,

Figur 13

einen Ballonbegrenzer mit zwei Begrenzungselementen in einer Ruhestellung in einer Draufsicht,

Figur 14

den Ballonbegrenzer der Figur 12 in einer Arbeitsstellung,

Figur 15

einen Ballonbegrenzer mit zwei Begrenzungselementen in einer ersten Stellung in einer Draufsicht, sowie

Figur 16

den Ballonbegrenzer der Figur 15 mit den beiden Begrenzungselementen in einer zweiten Stellung.

Further advantages of the invention are described in the following exemplary embodiments. They show, each schematically:

figure 1

a front view of a winding machine with a large number of work stations arranged next to one another,

figure 2

a front view of a work station of a winding machine with a fully closed yarn tensioner,

figure 3

the place of work of figure 2 with a fully open yarn tensioner,

figure 4

a detailed view of a cop and a balloon limiting device according to a first embodiment at a first point in time at the beginning of the rewinding process in a front view,

figure 5

the cop and the balloon confinement device 4 at a second time during the rewinding process,

figure 6

the cop and the balloon confinement device 4 at a third time during the rewinding process,

figure 7

a detailed view of a cop and a balloon limiting device according to a second embodiment at a first point in time at the beginning of the rewinding process in a front view,

figure 8

the cop and the balloon confinement device 7 at a second time during the rewinding process,

figure 9

the cop and the balloon confinement device 7 at a third time during the rewinding process,

figure 10

a representation of the yarn pull-off force during the winding process and a limit value for the yarn pull-off force,

figure 11

a representation of the yarn pull-off force during the winding process and a fluctuation range of the yarn pull-off force,

figure 12

a detailed representation of a twine tensioner and the detection of the adjustment path of the twine tensioner in a front view,

figure 13

a balloon limiter with two limiter elements in a rest position in a plan view,

figure 14

the balloon limiter figure 12 in a working position

figure 15

a balloon limiter with two limiter elements in a first position in a plan view, and

figure 16

the balloon limiter figure 15 with the two limiting elements in a second position.

In the following description of the exemplary embodiments, identical features or features that are at least comparable in terms of their design and/or mode of action are provided with the same reference symbols. Furthermore, these are only explained in detail when they are mentioned for the first time, while in the following exemplary embodiments only the differences from the exemplary embodiments already described are discussed. Furthermore, for reasons of clarity, of several identical components or features, often only one or just a few are labeled.

figure 1 shows a schematic front view of a winding machine 1. The winding machine 1 has a multiplicity of work stations 2 arranged next to one another, which are located between two frames 21, of which only in the present case one is shown. The work stations 2 are designed to unwind a yarn 3 from a cop 22 having a spinning tube 4 and to wind it onto a winding tube 6 by means of a winding device 5 . The workplaces 2 have numerous working bodies for this purpose. The working elements include a splicer 16, which connects a yarn end on the spinning tube side to a yarn end on the bobbin tube side after a yarn break, a cleaner cut or the spinning tube 4 has run dry, a movable suction nozzle for locating a yarn end on the bobbin tube side and a movable suction pipe 20 for locating a yarn end on the spinning tube side . The work station also has a yarn clearer 12 .

The winding machine 1 has a central control device 13 which controls the operations on the winding machine 1 . In addition, as shown here, each of the work stations 2 can also have a work station's own control device 13 which is connected to the central control device 13 and which controls the processes at the individual work station 2 .

The yarn 3 wound on the spinning tube 4 is withdrawn from the spinning tube 4 and passes through a balloon limiter 23, a yarn guide 15 and a yarn tensioner 7, which exerts an adjustable yarn withdrawal force on the running yarn 3 (see Fig. Figures 10 and 11 ) raises. For this purpose, the yarn tensioner 7 can be controlled accordingly by a control device 13 of the winding unit 2 . In the present case, a tensile force sensor 10 is arranged near the bobbin tube 6 in order to measure the yarn withdrawal force. Depending on the yarn pull-off force measured, the yarn tensioner 7 is adjusted and the yarn pull-off force is thereby regulated.

The yarn tensioner 7 is now based on the Figures 2 and 3 explained in more detail. while showing figure 2 a work station 2 in a schematic front view. The yarn tensioner 7 is shown in a closed position GP. In regular winding operation, the yarn tensioner 7 assumes a partially closed position, so that the yarn 3 is deflected several times at the yarn tensioner 7 and is thereby subjected to friction. The yarn pull-off force can be influenced by opening or closing the yarn tensioner 7 further. The yarn tensioner 7 shown here is designed as a rack tensioner and has two tensioning elements 8 that can be moved relative to one another by means of a drive 9 . Only one of the two clamping elements 8 can be moved or both clamping elements 8 can be moved, as is shown here. Furthermore, a yarn balloon 14 forming between the spinning tube 4 and the winding tube 6 during the rewinding process is also indicated in this representation.

figure 3 shows the fully open position OP of the yarn tensioner 7, in which the yarn 3 passes through the yarn tensioner 7 freely and without contact. Accordingly, no tension is applied to the yarn 3 in this position.

By means of the yarn tensioner 7 it is possible to regulate the yarn withdrawal force over a wide range of the winding process and to keep it largely constant. However, as soon as the yarn tensioner 7 has reached the fully open position OP or the closed position GP or the tensioning element or elements 8 have reached their end position, the yarn withdrawal force can no longer be influenced by means of the yarn tensioner 7 . In order to continue to keep the yarn pull-off force low, it is therefore provided that the shape and size of the yarn balloon 14 be limited by means of a balloon limiting device 18 (see Fig. 4 ) depending on the yarn pull-off force.

figure 4 12 shows a first embodiment of a balloon limiting device 18 and a cop 22 with a spinning tube 4. The balloon limiting device 18 has a balloon limiter 23, 26, which in the present case is designed as a balloon constricting ring. The balloon limiter 23,26 has a yarn guide surface 24, 27, which has a specific distance a1, a2 from an axis of rotation 25 of the cop 22 or the spinning tube 4. Again figure 4 still further removable, the balloon confinement device 18 communicates with a control device 13, as indicated by the dotted line. The control device 13 is in turn connected to a detection device 17 which detects the yarn pull-off force or a measured variable representing the yarn pull-off force. the figure 4 shows the job 2 or the cop 22 at the beginning of the rewinding process. The spinning tube 4 is still completely wound at this point in time. The yarn balloon 14 that is being formed therefore has only a comparatively small height and a comparatively small width at this point in time. In the present example, the balloon limiter 23, 26 is positioned at a fixed height relative to the spinning tube 4 during the entire rewinding process, and is therefore not moved along the axis of rotation 25.

figure 5 shows the cop 22 or the job 2 of figure 4 at a further point in time of the rewinding process, after a piece of the yarn 3 wound on the spinning tube 4 has already been unwound. It can be seen that the spinning tube 4 is gradually freed from the yarn from top to bottom during the unwinding and the upper cop cone therefore moves further down. The yarn balloon has therefore become larger, so that the yarn guide surface 24, 27 now acts on the yarn 3 and limits the yarn balloon 14 in the width direction. This has resulted in a double balloon, as a result of which the centrifugal forces in the yarn balloon 14 and thus also the yarn pull-off force are reduced. A first portion of the yarn 3 located on the spinning tube 4 is now unwound, with the yarn balloon 14 being delimited by the yarn guide surface 24,27.

However, especially in the second half of the rewinding process, there is an increase in the yarn pull-off force, despite the limitation imposed by the yarn guide surface 24,27. If the detection device 17 increases by one If a predetermined value is detected, the distance a1, a2 of the yarn guide surface 24, 27 from the axis of rotation 25 is reduced on the basis of this signal from the detection device 17.

figure 6 shows the cop 22 and the balloon limiting device 18 of FIGS. 4 and 5 at a third point in time, at which the distance a1, a2 of the yarn guide surface 24, 27 from the axis of rotation 25 has just been reduced. A second part of the yarn 3 is now unwound from the spinning tube 4, with the yarn guide surface 24, 27 now acting on the yarn balloon 14 with the reduced distance a1, a2. The yarn balloon 14 now becomes even higher following the winding state of the spinning tube 4, but further expansion in the width direction is counteracted by the fact that the yarn balloon 14 is now limited with the yarn guide surface 24, 27 that is constricted to a smaller distance a1, a2.

The reduction of the distance a1, a2 of the yarn guide surface 24,27 can be done, for example, by moving two or more limiting elements 29 of the balloon limiter 23,26 from a first position I to a second position II, as later with reference to FIG Figures 15 and 16 is described.

figure 7 shows a second embodiment of a balloon limiting device 18. This has a first balloon limiter 23, which is also designed as a balloon constriction ring and has a yarn guide surface 24 at a distance a1 from an axis of rotation 25 of the cop 22 or the spinning tube 4. Furthermore, the balloon delimitation device 18 has a second balloon delimiter 26 with a second yarn guide surface 27 . The second balloon limiter 26 is from a rest position R, which is in the Figures 7 and 8 is shown in a working position A, which is in the figure 9 is shown, transferable. Again, the balloon limiting device 18 is with the Control device 13 in connection, as shown by the dotted line. figure 7 12 again shows the cop 22 at the beginning of the rewinding process when the spinning tube is still completely wound.

figure 8 shows the cop 22 or the job 2 of figure 7 now during the unwinding of a first part of the yarn 3 wound on the spinning tube 4, the yarn guide surface 24 of the first balloon limiter 23 acts on the yarn 3 and limits the yarn balloon 14 in the width direction. The second balloon limiter 26 is still in its rest position R. In order to move the second balloon limiter 26 to its working position A (see 9 ) to be transferred, are again delimiting elements 29 (see Fig. 13-16 ) Convertible from a first position I into a second position II. In the present example, this is done by pivoting the delimiting elements 29 through 90°. The balloon limiter 26 is thus designed as a divisible balloon constriction ring.

figure 9 finally shows the cop 22 and the balloon limiter 18 of FIG Figures 7 and 8 at a point of time just after an increase in yarn withdrawal force has been detected by the detector 17. On the basis of the signal from the detection device 17, the balloon delimitation device 18 was in turn activated by the control device 13 and the second balloon delimiter 26 was transferred from its rest position R to its working position A. In working position A, the second yarn guide surface 27 is at a distance a2 from the axis of rotation 25, which in the present case is less than the distance a1 between the first yarn guide surface 24 and the axis of rotation 25. A second part of the yarn 3 is now unwound from the spinning tube 4, the second yarn guide surface 27 now acting at the second distance a2 on the yarn balloon 14 and limiting it.

Deviating from that in the Figures 7-9 illustrated embodiment, the distance a2 of the second balloon limiter 26 to the axis of rotation 25 does not have to be is necessarily smaller than the distance a1 of the first balloon limiter 23. It would also be conceivable for the first yarn guide surface 24 and the second yarn guide surface 27 to act on the yarn balloon 14 and limit it at the same time. Depending on the distance between the two balloon limiters 23, 26, a multiple balloon is formed in this case.

Furthermore, it differs from the representation of Figures 7-9 also possible that the balloon limiting device 18 as well as that of Figures 4-6 has only a single balloon limiter 23,26, which can be converted from a rest position R into a working position A. This can then also be activated when an increase in the yarn pull-off force is detected (see Figures 10 and 11 ) are transferred from the rest position R to the working position A based on a signal from the detection device 17 .

It is also possible for several balloon limiters 23, 26 to be combined in a balloon limiter device 18, which are transferred from their rest position R to their working position A one after the other or in some cases simultaneously when an increase in the yarn pull-off force is detected, or in each case when an increase in the yarn pull-off force is detected Garnabzugskraft the distance a1, a2 to the axis of rotation 25 is reduced. The different configurations of balloon limiters 23, 26 can also be combined in a single balloon limiter device 18.

In order to trigger the transfer from the rest position R to the working position A and/or the reduction of the distance a1, a2, a limit value 28 for the yarn pull-off force can be specified, for example. this is in figure 10 shown.

Finally, it is also possible that the two balloon limiters 23, 26 or even further balloon limiters 23, 26 are arranged together at the work station 2 so that they can be adjusted in height. The balloon limiters can do this 23, 26 can be arranged, for example, on a common carrier which is mounted in a displaceable and drivable manner on a guide extending in the direction of the axis of rotation 25. The balloon limiters 23,26 can be arranged at a constant height in relation to the spinning tube 4 during the rewinding process, but can be moved to a cop changing position above the spinning tube to remove an empty spinning tube 4 and replace a fully wound spinning tube 4.

figure 10 shows the progression of the yarn pull-off force over the entire rewinding process or the run length of the yarn, as this would progress without the balloon being influenced. It can be seen that the yarn pull-off force is largely constant over the first half of the rewinding process, while it increases in the second half. It can also be seen that towards the end of the rewinding process, especially in the last third, there is an exponential increase in the yarn pull-off force. Since smaller fluctuations in the yarn pull-off force tend to be unproblematic and can generally still be compensated for by the yarn tensioner 7, a value can be assumed as limit value 28, for example, which is 20% above the value of the yarn pull-off force in the first half of the rewinding process.

Alternatively, it is also possible not to use the exceeding of a limit value 28 as the triggering signal, but rather the exceeding of a fluctuation range 30. This is in figure 11 shown.

Since smaller fluctuations in the yarn pull-off force are not a problem, a permissible fluctuation range 30 of 5-10 N can be specified within a certain comparison period, for example. The yarn pull-off force is continuously recorded and compared with previous measured values of the comparison period. If the permissible fluctuation range of 30 is exceeded, as stated in figure 11 is shown, this is detected by the detection device 17 and a signal is output to the control device 13 . The control device 13 can then based on this signal control the reward limiting device 18 in order to bring an additional balloon limiter 23,26 into effect or to reduce a distance a1, a2 of the yarn guide surface 24,27 from the axis of rotation 25.

As a further alternative, it is also possible not to measure the yarn pull-off force directly, but instead to measure a measured variable that represents the yarn pull-off force. this is in figure 12 shown.

figure 12 10 shows a detailed view of a yarn tensioner 7 with two tensioning elements 8 that can be moved by means of a drive 9. As already mentioned at the outset, the drive 9 is controlled on the basis of signals from a tensile force sensor 10, which measures the yarn withdrawal force. The current adjustment path s, which is shown here as an example for the tensioning element 8 shown in the figure on the right, or the current position of the tensioning element or elements 8, is therefore an indirect parameter for the yarn pull-off force.

In the present example, a sensor 11 detects whether the tensioning element 8 is in its fully open position OP. The closed position GP of the yarn tensioner 7 is also shown in dot-dash lines. However, the adjustment path s covered could also be detected by means of a path sensor.

the Figures 13 and 14 finally show a balloon limiter 23, 26, which has two limiting elements 29, which, from a first position I, in figure 13 is shown, are movable into a second position II, which is in figure 14 is shown. For this purpose, the two delimiting elements 29 are pivotably mounted (in the present case, however, they are shown broken off). In the present example, the balloon limiter 23, 26 is in a rest position R when the limiter elements 29 are in the first position I. In the rest position R the balloon limiter limits 23.26 den Yarn balloon 14 not. Since in this rest position R the delimiting elements 29 have moved far outwards from the circumference of the cop 22, the rest position R can also serve as a cop changing position.

in the in figure 14 In contrast, the working position A of the balloon limiter 23, 26 shown, the limiting elements 29 assume the second position II. In this position, the delimiting elements 29 form a closed balloon constriction ring and can delimit the yarn balloon 14 .

Again figure 14 further removable, due to the fact that the balloon limiter 23,26 has a rest position R, it is also possible that the diameter of the yarn guide surface 24,27 of the balloon limiter 23,26 is smaller than the outer diameter of the cop 22. If this is the case, then so the balloon limiter 23, 26 can only be moved into its working position A when at least an upper part of the spinning tube 24 is already exposed.

the Figures 15 and 16 show another embodiment of a balloon limiter 23, 26 with limiter elements 29, which can be moved from a first position I to a second position II. This embodiment of a balloon limiter 23,26 can advantageously be used to reduce the distance a1, a2 of the yarn guide surface 24,27 from the axis of rotation 25 of the cop 22 or the internal dimension, here the inside diameter, of the yarn guide surface 24,27. There are in figure 15 the limiting elements 29 are in the first position I, in which the yarn guide surface 24,27 forms a larger diameter. In figure 16 however, the limiting elements 29 are in a second position II, in which the yarn guide surface 24, 27 is constricted and thus has a smaller diameter and thus also a reduced distance a1, a2 from the axis of rotation 25. The distance a1, a2 and the axis of rotation 25 are in the Figures 4 - 6 evident and in the Figures 15 and 16 not shown.

In the figures described here, the respective balloon limiter 23, 26 is transferred from the rest position R to the working position A by moving the movable limiter elements 29 from a first position I to a second position II. However, it is also possible for one or more balloon limiters 23, 26 to be arranged at the work station 2 so as to be movable overall, for example movable along the axis of rotation 25, in order to move out of their rest position R, which is, for example, above the cop 22 near the yarn guide 15 (see Figures 2 - 9 ) could be arranged to be transferred to their working position A.

The invention is not limited to the illustrated and described embodiments. Modifications within the scope of the patent claims are just as possible as any combination of the features described, even if they are shown and described in different parts of the description or the claims or in different exemplary embodiments, provided that there is no contradiction with the teaching of the independent claims.

Reference List

1

Dishwasher

2

place of work

3

yarn

4

spinning tube

5

spooling device

6

bobbin case

7

Yarn Tensioner

8th

clamping element

9

Drive of the clamping element

10

draft sensor

11

sensor

12

yarn clearer

13

control device

14

yarn balloon

15

yarn guide

16

splicer

17

detection device

18

balloon confinement device

19

suction nozzle

20

intake manifold

21

frame

22

cop

23

first balloon limiter

24

first yarn guide surface

25

axis of rotation

26

second balloon limiter

27

second yarn guide surface

28

limit

29

boundary element

30

range of fluctuation

A

working position

R

rest position

a1

first distance

a2

second distance

s

adjustment range

I

first position

II

second position

gp

closed position of the twine tensioner

OP

open position of the twine tensioner

Claims (15)

Method for operating a work station (2) of a winding machine (1), in which a yarn (3) is rewound from a cop (22) having a spinning tube (4) onto a winding tube (6) by means of a winding device (5), a yarn balloon (14) forming between the spinning tube (4) and the bobbin tube (6) during the rewinding process is limited at least in a width direction by means of a balloon limiting device (18), wherein the balloon limiter (18) comprises at least one balloon limiter (23, 26) with a yarn guide surface (24, 27) which can be transferred from a rest position (R) into a working position (A), a first portion of the yarn (3) on the spinning tube (4) being rewound onto the winding tube (6), with a yarn pull-off force of the yarn (3) and/or a measured variable representing the yarn pull-off force being recorded, the yarn guide surface (24 , 27) in the working position (A) of the at least one balloon limiter (23, 26) at a distance (a1, a2) from an axis of rotation (25) of the spinning tube (4), characterized, that upon detection of an increase in the yarn pull-off force by a predetermined value the at least one balloon limiter (23, 26) of the balloon limiter (18) is transferred from the rest position (R) to the working position (A), and that a second portion of the yarn (3) on the spinning tube (4) is then rewound onto the bobbin tube (6), the yarn balloon (14) being delimited by the yarn guide surface (24, 27). Method for operating a work station (2) of a winding machine (1), in which a yarn (3) is rewound from a cop (22) having a spinning tube (4) onto a winding tube (6) by means of a winding device (5), a yarn balloon (14) forming between the spinning tube (4) and the bobbin tube (6) during the rewinding process is limited at least in a width direction by means of a balloon limiting device (18), wherein the balloon limiting device (18) comprises at least one balloon limiter (23, 26) with a yarn guide surface (24, 27), with a first part of the yarn (3) located on the spinning tube (4) being rewound onto the bobbin tube (6), wherein a yarn pull-off force of the yarn (3) and/or a measured variable representing the yarn pull-off force is recorded, wherein during the rewinding of the first portion of the yarn (3), the yarn balloon (14) is delimited by means of the yarn guide surface (24, 27) and wherein the yarn guide surface (24, 27) is at a distance (a1, a2) at a distance (a1, a2) from a axis of rotation (25) of the spinning tube (4), characterized, that upon detection of an increase in the yarn pull-off force by a predetermined value the distance (a1, a2) of the yarn guide surface (24, 27) to the axis of rotation (25) of the spinning tube (4) is reduced and that a second part of the yarn (3) on the spinning tube (4) is then rewound onto the bobbin tube (6), the yarn balloon (14) being guided by the yarn guide surface (24, 27) at a reduced distance (a1, a2) is limited to the axis of rotation (25). Method for operating a work station (2) of a winding machine (1), in which a yarn (3) from a cop (22) having a spinning tube (4) is placed on a winding tube by means of a winding device (5). (6) is rewound, a yarn balloon (14) forming between the spinning tube (4) and the bobbin tube (4) during the rewinding process is limited at least in a width direction by means of a balloon limiting device (18), wherein the balloon limiter (18) comprises a first balloon limiter (23) with a first yarn guide surface (24), a first portion of the yarn (3) on the spinning tube (4) being rewound onto the bobbin tube (6), the yarn balloon (14) being delimited by means of the first yarn guide surface (24) and a yarn withdrawal force of the yarn (3) and/or a measured variable representing the yarn pull-off force is recorded, the first yarn guide surface (24) of the balloon limiter (23) being at a first distance (a1) from an axis of rotation (25) of the spinning tube ( 4) has, characterized in that that upon detection of an increase in the yarn pull-off force by a predetermined value the first distance (a1) of the first yarn guide surface (24) to the axis of rotation (25) of the spinning tube (4) is reduced and that a second part of the yarn (3) on the spinning tube (4) is then wound onto the bobbin tube (6) is rewound, the yarn balloon (14) being limited by the first yarn guide surface (27) at a reduced distance (a1) from the axis of rotation (25). and/or that at least one second balloon limiter (26) of the balloon limiter (18) is transferred from a rest position (R) to a working position (A) with a second yarn guide surface (27), and that then a second part of the spinning tube ( 4) located yarn (3) is rewound onto the bobbin tube (6), wherein the yarn balloon (14) is limited by the second yarn guide surface (27). Method according to the preceding claim, characterized in that the second yarn guide surface (27) in the working position (A) of the second balloon limiter (26) has a second distance (a2) from the axis of rotation (25) of the spinning tube (4), which is smaller than the first distance (a1). Method according to one of the preceding claims, characterized in that a limit value (28) for the yarn pull-off force and/or the measured variable representing the yarn pull-off force is specified and, if the limit value (28) is exceeded, the balloon limiter (23, 26) moves into its working position (A) is transferred and/or the distance (a1, a2) is reduced. Method according to one of the preceding claims, characterized in that a permissible fluctuation range (30) of the yarn pull-off force and/or of the measured variable representing the yarn pull-off force is defined and, if the fluctuation range (30) is exceeded, the balloon limiter (23, 26) moves into its working position (A) is transferred and/or the distance (a1, a2) is reduced. Method according to one of the preceding claims, characterized in that a position and/or an adjustment path (s) of a tensioning element (8) of a yarn tensioner (7) is detected as the measured variable representing the yarn withdrawal force. Work station (2) of a winding machine (1) for rewinding a yarn (3) from a cop (22) having a spinning tube (4) onto a winding tube (6) by means of a winding device (5) with a balloon limiting device (18) for limiting a yarn balloon (14) forming between the spinning tube (4) and the bobbin tube (6) during the rewinding process, at least in a width direction, the balloon limiting device (18) having a includes a first balloon limiter (23) with a first yarn guide surface (24) which is at a first distance (a1) from an axis of rotation (25) of the spinning tube (4) at least during rewinding, with at least one detection device (17) for detecting a yarn pull-off force of the yarn (3) and/or a measured variable representing the yarn pull-off force and with a control unit (13) which is connected to the at least one detection device (17), characterized, that the control unit (13) is connected to the balloon limiting device (18). and that the first balloon limiter (23) of the balloon limiter (18) can be transferred from a rest position (R) to a working position (A) as a function of a signal from the at least one detection device (17) or that the first distance (a1) of the first yarn guide surface (24) can be reduced to the axis of rotation (25) of the spinning tube (4) as a function of a signal from the at least one detection device (17). and/or that the balloon limiting device (18) contains at least one second balloon limiter (26) with a second yarn guide surface (27) which, depending on a signal from the at least one detection device (17), moves from a rest position (R) into a working position (A) is transferable. Work station (2) according to the preceding claim, characterized in that the second yarn guide surface (27) in the working position (A) of the at least one second balloon limiter (26) is a second distance (a2) from the axis of rotation (25) of the spinning tube (4) has, which is less than the first distance (a1). Work station (2) according to one of the preceding device claims, characterized in that the at least one detection device (17) is a tensile force sensor (10). Work station (2) according to one of the preceding device claims, characterized in that the at least one detection device (17) is a proximity switch or a distance sensor or a detection sensor, in particular an optical sensor (11) or a displacement sensor (11). Work station (2) according to one of the preceding device claims, characterized in that the at least one detection device (17) is a controller for a drive (9). Work station (2) according to one of the preceding device claims, characterized in that the first balloon limiter (23) and/or the at least one second balloon limiter (26) is a balloon constriction ring. Work station (2) according to one of the preceding device claims, characterized in that the first and/or the at least one second balloon limiter (23, 26) has at least two limiter elements (29) which can be moved from a first position (I) to a second position ( II) are movable. Work station (2) according to one of the preceding device claims, characterized in that the first and/or the at least one second balloon limiter (23) can be transferred into a cop changing position.

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