EP1951605A1

EP1951605A1 - Method for avoiding ribbon windings

Info

Publication number: EP1951605A1
Application number: EP06818388A
Authority: EP
Inventors: Maximilian Preutenborbeck; Jürgen Meyer; Manfred Lassmann; Olaf Reissig; Gregor Gebald
Original assignee: Oerlikon Textile GmbH and Co KG
Current assignee: Oerlikon Textile GmbH and Co KG
Priority date: 2005-11-15
Filing date: 2006-11-07
Publication date: 2008-08-06
Also published as: CN101291862A; WO2007057109A1; DE102005054356A1; US20090134263A1

Abstract

The invention relates to a method for avoiding ribbon windings in the production of winding-on bobbins which are wound as a ‘randomly wound package’ type on the workstations of textile machines which manufacture crosswound bobbins, by changing the crosswinding, with which the thread is wound onto the winding-on bobbin, wherein the workstations have in each case a single-motor drive which can be actuated in a defined manner for rotating the crosswound bobbin and a single-motor drive which can be actuated in a defined manner for an oscillating thread guide. According to the invention, there is provision for the diameters (DSP k) of the crosswound bobbin (8) to be determined which are dependent on the width (BSp) of the crosswound bobbin (8) and a crosswinding angle (α) which is selected during winding of the crosswound bobbin (8) and are particularly critical with regard to a ribbon winding, for the crosswinding angle (α) to be changed in each case briefly before a critical diameter (DSP k) of this type is reached to a value (α1) which precludes the production of a ribbon winding in this diameter region, and for the crosswinding angle (α1) to be reset again to its original value (α) after the critical diameter (DSP k) has been passed.

Description

Description:

Method for avoiding image windings

The invention relates to a method for avoiding image windings in the creation of package creels according to the preamble of claim 1.

In the preparation of packages on workstations of cheese-producing textile machines, for example, in an open-end spinning device, supplied at a constant speed to a winding device yarn when moving onto a bobbin by a traversing yarn guide so shifts that he in intersecting layers on the Coil runs up and forms a so-called cross-wound bobbin. In the manufacture of cross windings in the winding type "wild winding", however, there is the problem that, if no special measures are taken, in the course of the coil travel repeatedly comes to so-called image windings. Such image windings always occur when there is an integer turn ratio, that is, when the cross-wound bobbin makes one or more complete revolutions per double stroke of the traversing yarn guide.

In such a case, the reversal points of the thread substantially over the reversal points of the previous stroke, so that the thread is deposited several times at the same or at an immediately adjacent location on the Spulumfang, resulting in ribbon-like thread layers, which are referred to as image windings leads , Since with such an inhomogeneous structure of the yarn layers when unwinding the cheeses often comes to stripping complete yarn layers of the bobbin surface, resulting in serious malfunction, such image windings must be avoided at all costs.

For the avoidance of image windings, therefore, various methods and devices have been known for a long time, which are known in the art

Coil structure to overcome the above problem should serve.

In these so-called Bildstörverfahren and facilities in the Bildwickelgefährdeten areas of the cheese is influenced on the turns ratio.

In DE 25 34 239 C2, for example, a method and apparatus for image disturbance are described in which / is trying by constantly changing the crossing angle to prevent the formation of integer Windungsverhältnisse. The traversing yarn guide a machine side are driven together by a first drive with at least two different speeds and the winding rollers of this machine side can be acted upon jointly by a second drive.

The two drives are also connected via an electronic gear such that synchronously and depending on the movement of the traversing yarn guide the winding rollers and thus the cheeses are driven so that the quotient of peripheral speed of the cheeses and cosine of the half cross-hair angle is constant.

That is, in this known method, an attempt is made to avoid both integer winding conditions, as well as resulting winding speed of the thread and thus to keep the thread tension almost constant.

From DE 43 37 891 Al a Bildstörverfahren is known in which a supplied at a constant speed and after the manner of "wild winding" wound on a cross-wound yarn to avoid image windings with a variable traversing speed is wound.

The device has a single motor driven winding roller and a single motor driven traversing yarn guide.

In this known Bildstörverfahren the traversing speed of the thread guide is subjected to a non-periodic change.

The maximum and minimum values of the traversing speed, in each case a changeover from an acceleration to a deceleration and vice versa, as well as the time intervals between the reversal points, are thereby changed by means of a computer within predetermined limits.

From DE 196 28 402 Al further a Bildstörverfahren is known, in which, similar to the device according to DE 25 34 239 C2, the winding rollers of a machine side are acted upon together by a first drive and the yarn guide this machine side together by another drive ,

The traversing speed of the yarn guides and the circumferential speed of the winding rollers are constantly changed in opposite directions between predetermined maximum and minimum values around a mean value. One of the two speeds forms the guide variable, which is tracked to the other speed in each case as a consequence of the process.

In each case, when the leading variable has reached a maximum or minimum value, a signal is generated at the beginning of its opposite change, which triggers the opposite change in the sequence size.

Also in DE 102 09 851 Al a Bildstörverfahren for cheeses is described, which are wound in the winding type "wild winding".

In this known method, the rotational speed of the winding roller is determined depending on the delivery speed of the thread, the Anspannverzuges and the crossing angle and changed for the purpose of image distortion of the crossing angle by changing the speed of the traversing yarn.

The drive for the winding rollers and the drive for the traversing yarn guides are designed as variable-speed motors, which is delivered to the value representing the desired crossing angle signal from which the motors derive the required engine speed.

However, the aforementioned Bildstörverfahren or Bildstöreinrichtungen have the disadvantage that they are all relatively complicated or expensive.

That is, for carrying out the known method either requires a high mechanical and control engineering effort, or the Bildstörverfahren lead during the winding of the cheeses to unsatisfactory results. Based on the aforementioned prior art, the present invention seeks to provide a relatively simple method for avoiding image windings, which is particularly advantageous for jobs that have single-motor drives for the winding roller and the traversing yarn guide.

This object is achieved by a method as described in claim 1.

Advantageous embodiments of the invention are the subject of the dependent claims.

The inventive method offers the possibility that

Developing image windings already in the beginning thereby reliably preventing suitable measures for

Picture disturbance already be taken before, while winding a

Cheese crosses a critical area is reached.

That is, just before reaching such, through the

Coil width and the crossing angle predetermined critical

Range is changed by changing the crossing angle

Windungsverhältnis defines adjusted so that the formation of image windings is reliably excluded.

The modified crossing angle is maintained until the critical diameter range of the cross-wound bobbin is passed through.

Subsequently, it is returned to the original crossing angle and continue to be wound with this crossing angle until, during the course of the coil travel, the diameter of the cross-wound bobbin approaches the next critical diameter range. As set forth in claim 2, the critical diameter ranges of a cross winding wound in the winding winding mode are advantageously calculated according to the formula: D _s pk = A x B _S p / π x tan (α / 2), where D _{SP k represents} a critical diameter range of the cheese, A is an integer, B _{SP is} the respective bobbin width of the cheese and α is the selected crossing angle of the cheese. The diameter data can be calculated, for example, in a workstation computer and processed to the effect that in each case in good time before reaching a critical diameter range of the cheese from the workstation a change in the crossing angle is initiated. As a critical diameter range while the areas of the cheese are referred to, in which an integer turns ratio is present, that is, in which the cheese performs per double stroke of the traversing yarn due to the present diameter one or more complete revolutions.

As set forth in claim 3, it is provided in an advantageous embodiment that the crossing angle is reduced shortly before reaching a critical package diameter, by reducing the speed of the traversing yarn guide.

The reduction of the crossing angle leads directly to a change in the turns ratio with the consequence that it can not come to the formation of image windings in this per se critical diameter range of the cheese.

As set out in claim 4, the workstation computer preferably initiates a speed to change the crossing angle. Change in the traversing thread guide. At the same time, in addition, the rotational speed of the winding roller and thus the winding speed of the cross-wound bobbin are adjusted so that the thread tension of the running thread remains almost constant. That is, the speeds of traversing yarn guide and winding roller are adjusted so that the resultant of the laying speed of the traversing yarn guide and the rotational speed of the winding roller always remains almost the same.

According to claim 5, the drive of the traversing yarn guide is preferably designed as a stepper motor.

Such stepper motors are cost-effective mass-produced components, which are also very precisely controlled in a relatively simple manner.

That is, with such stepper motors, for example, a very precise displacement of the traversing yarn guide is possible, with the control engineering effort keeps within reasonable limits.

The invention will be explained in more detail with reference to an embodiment shown in the drawings.

It shows:

1 is a side view of a workstation of an open-end rotor spinning machine producing cross-wound bobbins, with a winding device operating according to the method of the invention, FIG. 2 shows schematically on a larger scale the winding device required for carrying out the method according to the invention,

3 is a diagram illustrating the relationship between the rotational speed of the winding roller and the speed of the traversing yarn guide, especially when changing the crossing angle,

4 shows schematically the yarn path in a cross-wound bobbin, which has reached a critical diameter range.

1 shows schematically in side view one half of a cross-wound textile machine 1, in the embodiment of an open-end rotor spinning machine, is shown. Such textile machines have, as is known, between their (not shown) Endgestellen a plurality of similar jobs 2, which, inter alia, each have a spinning unit 3 and a winding device 4. In the spinning units 3 slivers 6, which are stored in sliver cans 5, processed into threads 7, which are then wound on the winding devices 4 to cheeses 8.

The finished cross-wound bobbins 8 are conveyed, for example via a cross-wound bobbin transport device 12, to a loading station (not shown) arranged on the machine end.

As further indicated in FIG. 1, the individual work stations 2 have, in addition to the spinning unit 3 and the winding device 4, further handling devices. For example, a thread take-off device 10, a suction nozzle 17 or a paraffine 14 on.

The functions of these components are known and explained in detail in numerous patents.

The winding device 4 essentially has a creel 9, a winding roller 11 and a thread-changing device 16.

The winding roller 11, which can be acted upon by a single motor 13 by a drive, while driving the freely rotatably mounted in the reel frame 9 cross-wound bobbin 8 frictionally.

FIG. 2 shows, in a front view, schematically a winding device 4 required for carrying out the method according to the invention.

As indicated in the drawing, in a (not shown) creel freely rotatably supported cross-wound bobbin 8 on a winding roller 11 and is taken from this by frictional engagement.

The winding roller 11 is connected to a drive 13, which in turn is connected via a control line 23 to a workstation computer 19 in connection.

For laying the thread 7 while it rests on the spool 8, a thread-changing device 16 is also provided, the traversing yarn guide 18 is driven by its own drive, preferably a stepping motor 20, oscillating.

Also, the stepper motor 20 is connected via a control line 24 to the Ärbeitsstellenrechner 19 and controlled by this controllable. Furthermore, a sensor device 21 is provided, which is connected via a signal line 22 to the workstation computer 19 and detects the respective rotational speed of the cross-wound bobbin 8 during the winding process.

That is, the workstation computer 19 is supplied with signals of the sensor device 21 and calculated on the basis of the rotational speed of the winding roller, the known diameter of the winding roller and determined by the sensor device 21 speed of the cheese 8 constantly the instantaneous diameter of the cheese 8.

FIG. 3 shows a diagram in which the speed V _{FF of} the traversing yarn guide 18 is shown on the abscissa and the rotational speed V _{m of} the winding roller 11 is shown on the ordinate.

As indicated, results during the regular spool travel at a speed Vi _{FF of} the yarn guide 18 and a rotational speed V ₁ w, the winding roller 11 a yarn running speed V _A i. The thread runs at an angle α / 2 on the cheese 8.

Shortly before reaching a critical diameter range Ds _{P k of} the cheese 8, the value of the yarn running angle α / 2 is changed to αχ / 2.

That is, the speed of the thread guide 18 becomes, as in

3, reduced to V _{2 FF} .

In order to keep the yarn running speed V _Ai = V _A2 constant, in addition, the rotational speed of the winding roller 11 is adjusted so that the winding roller 11 now rotates with V _{2 m} .

This means that from the orbital velocity V _m of

Winding roller 11 and the speed V _{FF of} the yarn guide 18th resulting resulting yarn running speed V _Ai or V _A2 remains constant regardless of crosshairs angle α or αi.

FIG. 4 shows a cross-wound bobbin 8 which has reached a first critical diameter range D _S p _{k which} depends on the bobbin width B _S p and the crossing angle α.

As indicated by the yarn path representing line 30 and the associated arrows 31 - 36, would be at this diameter of the cheese 8 and a crossing angle α per double stroke of the traversing yarn guide 18 several complete revolutions of the cheese 8 take place, with the result that the thread would be stored in overlying thread trays.

In order to avoid image windings, therefore, the value of the crossing angle α is changed to Qt ₁ shortly before reaching the critical diameter range D _S pk.

At an intersection angle αi and a coil width B _{SP, it} is ensured in the area of the cross-coil diameter D _{SP k} that no image windings can occur.

The yarn path adjusting at a crossing angle αi and a package width B _S p is indicated in FIG. 4 with reference to the line 40 or the associated arrows 41 - 49.

Function of the method according to the invention:

At the beginning of a batch, first the most important parameters of the cross-wound bobbin, for example the intended final diameter of the cheese 8, the bobbin width B _s p, the crossing angle α with which the cheese 8 is to be wound, as well as a further crossing angle αi are determined and, for example, in FIG Central control unit of a textile machine entered. The central control unit of a textile machine stands in turn, preferably via a bus connection or the like, with the individual workstation computers 19 of the workstations 2 in connection.

Based on the aforementioned data, the central control unit or the workstations computers 19 first calculate / calculate the critical diameter ranges D _{SP k of} the cross-wound bobbin, that is, the areas in which, if no special measures are taken, image windings would occur.

For example, the workstation computer 19 determines according to the formula: D _{SP k} = integer x coil width B _Sp / π x tan crossing angle α / 2, that with a coil width of, for example, 150 mm and a crossing angle of α = 36 °, the particularly critical diameter ranges of Cheese 8 at D _SP _k = 147 mm, 294 mm, etc. lie.

After the start of the spinning / spooling process, the speed of the cross-wound bobbin 8 is constantly monitored by means of the sensor device 21 and the actual diameter D _S p of the cross-wound bobbin 8 is calculated in the workstation computer 19 according to the formula: D _SP = Dww x nw "/ nsp.

When the workstation computer 19 determines that the diameter D _{SP of} the cross-wound bobbin 8 approaches a critical diameter range D _{SP k} , the value of the crossing angle α is changed to αi, for example, reduced from α = 36 ° to αi = 30 °. The reduction of the crossing angle α in αi is carried out by reducing the speed V _FF of the traversing yarn guide 18. That is, the workstation computer 19 controls the drive 20 of the Fadenchangiereinrichtung 16 in the sense "delay" on. In order to keep the thread tension of the thread 7 running on the cross-wound bobbin 8 constant, the workstation computer 19 simultaneously controls the drive 13 of the winding roller 11 in the sense of "accelerating".

That is, the peripheral speed V ^ _n , the winding roller 11 is increased so that the run-up speed V _{A of} the thread 7 remains almost constant on the cheese 8 despite changing the crossing angle.

The invention is not limited to the illustrated embodiment, in an alternative embodiment may be used as control computer instead of the workstation of course, section computer or the central control device of the textile machine used.

Claims

claims

1. A method for preventing image windings in the

Creation of packages, which are wound on the jobs of cross-wound textile machines in the winding type "wild winding" by changing the traversing speed with which the thread is wound onto the package, the work stations each have a defined controllable, single-motor drive for rotation of the cheese and have a defined controllable, single-motor drive for a traversing yarn guide,

characterized,

in that the diameters (D _{SP k} ) of the cross-wound bobbin (8) that are particularly critical with regard to the formation of image windings are determined by the width (B _Sp ) of the cross-wound bobbin (8) and a crossing angle (α) chosen during winding of the cross-wound bobbin (8) in that, shortly before reaching one of these critical diameters (D _{SP k} ), the crossing angle (α) is changed to a value ((Xi) which precludes the formation of image windings in this diameter range and in that after passing the critical diameter (D _{3P k} ) the crossing angle (αi) is restored to its original value (α).

2. The method according to claim 1, characterized in that the critical diameter (D _S p _k ) of the cheese (8) according to the formula (D _{SP k} ) = (integer) x coil width (B _Sp ) / π x tan half Crossing angle (α / 2) are determined.

3. The method according to claim 1, characterized in that the crossing angle (α) shortly before reaching a critical diameter (D _SP jj the cross-wound bobbin (8) is reduced.

4. The method according to any one of the preceding claims, characterized in that for changing the crossing angle (α) the speed (V _FF ) of the traversing yarn guide (18) is changed, at the same time the rotational speed (Vww) of the winding roller (19) is adjusted so that that the thread tension of the running thread (7) remains almost constant.

5. The method according to claim 4, characterized in that as the drive for the traversing yarn guide (18), a stepping motor (20) is used.