DE102021102656A1 - Method of operating a work station of a spinning machine and work station - Google Patents

Abstract

The invention relates to a method for operating a work station (1) of a spinning machine, in which a yarn (3) is drawn off from a spinning unit (4) at a take-off speed during normal operation, the yarn (3) being measured with the aid of a quality sensor (5) with regard to at least one yarn parameter is monitored, the yarn (3) being wound onto a tube (7) at a winding speed with the aid of a winding device (6) and a package (8) thus being formed, the yarn (3) being wound onto the tube (7) is moved back and forth along a traversing width (CB), and a stop sequence being initiated by the quality sensor (5) when a deviation (F) caused by a yarn defect from a target value of the at least one yarn parameter is detected. During the stop sequence, the winding speed is reduced, with a yarn loop (S) being formed due to the resulting difference in speed between the winding speed and the take-off speed. The invention also relates to a work station (1) of a spinning machine.

Description

The present invention relates to a method for operating a work station of a spinning machine, with a yarn being drawn off from a spinning unit at a take-off speed during normal operation, with the yarn being monitored with the aid of a quality sensor with regard to at least one yarn parameter, with the yarn being spooled with the aid of a winding device in a winding speed is wound onto a tube and a package is formed, the yarn being moved back and forth along a traversing width when being wound onto the tube, and a stop sequence being initiated by the quality sensor when a yarn defect-related deviation from a target value of the at least one yarn parameter is detected . Furthermore, the invention relates to a work station of a spinning machine.

Generic spinning machines and methods for operating a work station of such spinning machines are well known in the prior art. The spinning machines can be configured as air-jet spinning machines or rotor spinning machines, for example. The aim here is to initiate a stop sequence if at least one yarn parameter deviates from a target value.

For example, from the DE 10 2015 110 486 A1 discloses a method for operating a spinning station of a spinning machine, in which a stop sequence is initiated upon detection of a defined deviation of a monitored yarn parameter from at least one target value. As part of the stop sequence, the spinning unit and the winding unit are stopped in such a way that the yarn section produced last does not completely run onto the tube located in the winding device. The yarn section that has the detected deviation of the yarn parameter is often wound onto the tube with an indefinite length of subsequent yarn. This indefinite length of subsequent yarn then has to be unwound and cut off again. This creates a large amount of yarn waste.

The object of the present invention is to eliminate the disadvantages known from the prior art. The object is in particular to create a method for operating a work station of a spinning machine and a work station which makes it easier to search for the end of the yarn, improves the winding of the yarn onto the tube and/or reduces yarn waste.

The object is achieved by a method for operating a work station of a spinning machine and a work station with the features of the independent patent claims.

A method for operating a work station of a spinning machine is proposed, with a yarn being drawn off from a spinning unit at a take-off speed during normal operation. The spinning machine is preferably an air or rotor spinning machine. Depending on the type of spinning machine used, the spinning unit comprises, for example, a turbulence chamber or a rotor and produces the yarn from a supplied fiber material. The yarn is then withdrawn from the spinning unit by a withdrawal device. The take-off speed is the speed of the yarn at which it is taken off from the spinning unit. Furthermore, the work station generally includes other elements necessary for yarn production, such as a drafting system for drafting and/or an opening roller for separating the fiber structure.

After leaving the outlet of the spinning unit, the yarn is monitored with the aid of a quality sensor with regard to at least one yarn parameter. The yarn parameters are, for example, the thickness, the hairiness or other parameters characterizing the quality of the yarn or their fluctuations over time.

The yarn is then wound onto a tube with the aid of a winding device at a winding speed and a package is thus formed, the yarn being moved back and forth along a traversing width when being wound onto the tube. The work station has a traversing device for moving the yarn back and forth along the traversing width. The traversing width is the distance between the two turning points of the traversing device. The term sleeve means the body onto which the yarn is wound. The term spool means the combination of said tube and the yarn located on the tube. The winding speed is the speed at which the yarn is wound onto the tube or onto the surface of the bobbin. The winding speed is therefore the speed of the yarn just before it runs onto the tube or onto the bobbin. The winding speed is primarily dependent on the rotational speed of the tube or bobbin, the outer diameter of the bobbin, the traversing width and/or a traversing frequency at which the traversing device moves along the traversing width.

Upon detection of a yarn error-related deviation from a target value of at least a yarn parameter by the quality sensor, a stop sequence is then initiated. The yarn section that exhibits the deviation from the target value of the at least one yarn parameter caused by the yarn defect can be referred to as a defect. A stop sequence is a sequence that stops the normal operation of the work station. The stop sequence is the chronological sequence of different operations when normal operation is stopped. Individual elements such as the spinning unit, the winding device, the take-off device and/or the traversing device can be stopped step by step or simultaneously. In order to monitor the at least one yarn parameter of the yarn after leaving the outlet of the spinning unit, the quality sensor can be arranged between the spinning unit and the take-off device. Additionally or alternatively, the quality sensor can be arranged between the take-off device and the winding device.

According to the invention, the method provides for the winding speed to be reduced during the stop sequence, with a yarn loop being formed as a result of the resulting speed difference between the winding speed and the take-off speed. The take-off speed remains essentially constant and/or the reduction in the take-off speed is less than the reduction in the winding speed, so that the yarn loop is formed. The winding of the yarn is slowed down by reducing the winding speed during the stop sequence and thus after the detection of the deviation from the target value of the at least one yarn parameter caused by the yarn defect. The missing part of the yarn is therefore not wound onto the tube or the surface of the bobbin, or only at a slower rate. In addition, the position of the defect between the quality sensor and the winding device and/or on the spool can be localized more precisely due to the slowed-down winding. The yarn tension during the slow winding of the yarn onto the tube during the stopping sequence remains approximately constant despite the difference in speed due to the yarn loop formed. In this way, fluctuations in the yarn tension, which result from the reduction in the winding speed and/or from the back and forth movement of the traversing device along the traversing width with the traversing frequency, can be compensated for.

It is advantageous if the traversing width is reduced during the reduction in the winding speed and/or thereafter. By reducing the traversing width, the yarn runs onto the sleeve or onto the surface of the bobbin within this reduced traversing width. This can ensure that the defect then runs onto the bobbin within this traversing width. This makes it easier to find this defect. The lower yarn tension resulting from the reduction in the traversing width can be compensated for by enlarging the yarn loop. In this way, a constant yarn tension can continue to be guaranteed with a simultaneously smaller traversing width.

It is also advantageous if, following the reduction in the winding speed and/or after the reduction in the traversing width, the yarn is severed in the area of the yarn loop, with a resulting yarn end on the bobbin side being guided in the direction of the bobbin at the winding speed. If the yarn is severed in the area of the yarn loop following the reduction in winding speed, the yarn end is slowly guided towards the bobbin. Because of the reduced winding speed, the end of the yarn can be stopped before it runs up, in particular at a pick-up position. As a result, it can be found and/or picked up more easily during a subsequent piecing process. If the yarn is additionally or alternatively severed after the reduction of the traversing width in the area of the yarn loop, the position of the defect and/or the yarn end can also be limited in width when being guided in the direction of the spool.

It is also advantageous if the yarn loop is formed and/or severed in an intermediate store. The intermediate store preferably works pneumatically and sucks in the yarn by means of negative pressure. The maintenance of the yarn tension can be guaranteed by the buffer. If the yarn loop is severed in the intermediate store, the end of the yarn on the spool side can be guided out of the intermediate store again counter to the direction of the suction effect as it moves in the direction of the spool. The yarn end on the take-off side can be discharged or sucked off by means of the intermediate store, which in particular works pneumatically.

There are also advantages if the traversing width is reduced to almost zero, as a result of which the yarn runs onto the spool in at least one parallel winding. The reduction of the traversing width to approximately zero is to be understood here in such a way that the yarn can run onto the surface of the bobbin in approximately parallel windings. The windings of the yarn are lined up in a narrow width so that parallel windings are created. The defect runs onto the surface of the coil in the area of the at least one parallel winding. The coil side Gar end is preferably stopped before it runs onto the spool. By winding the yarn in parallel, it can then be unwound again in a simplified manner and fed back into the spinning unit in a piecing process that follows the stopping sequence.

It is also advantageous if the at least one parallel winding runs onto the coil in the middle. The traversing width, which is preferably reduced to approximately zero, is thus formed in the center of the coil. The defect runs centrally in the area of the at least one parallel winding onto the surface of the coil. The spool-side yarn end is preferably stopped before it runs onto the spool, the gripping position of the spool-side yarn end thus being arranged essentially in the center of the spool. Because the yarn end on the spool side is picked up in the middle, it can be found and/or picked up more easily.

It is advantageous if, after the yarn has been severed and/or a yarn monitor has detected that the yarn end on the bobbin side has passed, the take-off speed and/or the bobbin speed is reduced to a standstill. The yarn monitor is preferably arranged between the take-off device and the winding device and/or between the intermediate store forming the thread loop and the winding device. In this way, the end of the yarn on the bobbin side can be detected before it runs onto the bobbin. Additionally or alternatively, the traversing device can be stopped. This allows the stop sequence to be completed. The defect can then advantageously be removed and/or the piecing process can be started.

It is also advantageous if the winding device continues to be operated after the yarn monitor has detected that the yarn end on the bobbin side has passed, until the yarn section with the deviation caused by the yarn defect runs onto the surface of the bobbin and/or the yarn end on the bobbin side is arranged at a pick-up position. In this way, an always constant pick-up position can be guaranteed.

The invention also relates to a workstation of a spinning machine, with a take-off device for drawing off a yarn from a spinning unit, with a quality sensor for monitoring the yarn with regard to at least one yarn parameter, with a winding device for winding the yarn onto a tube, and with a traversing device for back and forth moving the yarn along a traverse width during winding. The workstation has a control unit or is operatively connected to a control unit that is designed to operate the workstation according to the preceding description, it being possible for the features mentioned to be present individually or in any combination.

It is advantageous if the work station has an intermediate store, preferably one that operates pneumatically, for forming a yarn loop.

It is also advantageous if the intermediate store has a yarn cutting device for cutting the yarn in the area of the yarn loop.

• 1 bis 4 eine schematische Darstellung des erfindungsgemäßen Verfahren zum Betreiben einer Arbeitsstelle einer Spinnmaschine.

Further advantages of the invention are described in the following exemplary embodiments. Show it:

• 1 until 4 a schematic representation of the inventive method for operating a workstation of a spinning machine.

1 shows a section of a schematic front view of a work station 1 of a spinning machine during normal operation. During normal operation, a yarn 3 is drawn off from a spinning unit 4 at a drawing-off speed by means of a drawing-off device 2 . The take-off device 2 is preferably designed in the form of a pair of take-off rollers. In the exemplary embodiment shown, the spinning unit 4 is a spinning nozzle with a turbulence chamber of an air spinning machine, in which fibers of a fiber material are twisted into the yarn 3 with the aid of a turbulent air flow. The feeding of the fiber material, which is usually realized by means of a drafting system in air-jet spinning machines, is not shown here.

If, alternatively, the work station 1 is a work station 1 of a rotor spinning machine, the fiber material is usually dissolved into its individual fibers with a dissolving device. Instead of a vortex chamber, the spinning unit 4 has a rapidly rotating rotor for forming the yarn 3 .

After leaving the spinning unit 4, the yarn 3 is monitored with the aid of a quality sensor 5 with regard to at least one yarn parameter. With the help of a yarn monitor 15, the presence of the yarn 3 can then also be monitored. The yarn 3 is then wound onto a sleeve 7 at a winding speed with the aid of a winding device 6, as a result of which a coil 8 is formed. A yarn guide element 9 can be arranged between the yarn monitor 15 and the winding device 6 for additional guiding of the yarn 3 . To produce a cross-wound bobbin, the yarn 3 is wound onto the sleeve 7 or onto the surface of the bobbin 8 using a traversing device 10 along a traversing width CB moved back and forth. In the exemplary embodiment shown, during normal operation of work station 1, the traversing width CB is selected such that the traversing device 10 can distribute the yarn 3 evenly over a winding width SB on the sleeve 7 or on the surface of the bobbin 8. For this purpose, the traversing width CB during normal operation of the work station 1 is essentially equal to the winding width SB.

The workplace 1 also has a control unit 11 . The control unit 11 is designed in such a way that it can operate the components of the work station 1 according to appropriately stored specifications, in particular according to the previous and/or following description. Additionally or alternatively, the control unit 11 can be arranged centrally on the spinning machine and operate one or more work stations 1 of the spinning machine according to the specifications. The control unit 11 is in operative connection with the work station 1 .

If, during normal operation of work station 1, there is a deviation F of the at least one yarn parameter from a target value due to a yarn defect, then, as in 2 shown, after the detection of the yarn defect-related deviation F by the quality sensor 5, a stop sequence is initiated.

In the following descriptions of the 2 until 4 illustrated embodiments are for features that compared to the previous embodiment of the 1 are identical and/or at least comparable in their design and/or mode of operation, the same reference numbers are used. If these are not explained again in detail, their design and/or mode of action corresponds to the design and mode of action of the features already described above.

At the beginning of the stop sequence, as in 2 shown, a yarn loop S is formed by reducing the winding speed and the resulting speed difference between the winding speed and the take-off speed. The winding speed is primarily dependent on the rotational speed of the sleeve 7 or the bobbin 8, which is introduced by the winding device 6, and its diameter. The take-off speed is primarily dependent on the rotational speed of the pair of take-off rollers of the take-off device 2 .

The work station 1 has an intermediate store 12 for forming the yarn loop S. For sucking in the yarn loop S, the intermediate store 12 is preferably operated pneumatically. As shown in the exemplary embodiment shown, the buffer store 12 is preferably arranged between the quality sensor 5 and the yarn monitor 15 or between the take-off device 2 and the yarn monitor 15 . Due to the slower winding speed, the deviation F caused by the yarn defect is then guided in the direction of the spool 8 at a slower rate.

The traversing width CB is reduced during and/or after the reduction in the winding speed. 3 shows this point in time of the stop sequence, with the traversing width CB being reduced to almost zero. Reducing the traversing width CB to approximately zero results in at least one parallel winding PW of the yarn 3 on the surface of the bobbin 8. In addition, the yarn loop S can be enlarged by reducing the traversing width CB.

After the winding speed has been reduced and the traversing width CB has been reduced, the yarn 3 is severed in the area of the yarn loop S using a yarn separating device 13 . A resulting yarn end 14 on the bobbin side is guided further in the direction of the bobbin 8 together with the deviation F caused by the yarn defect with the winding speed. This time of the stop sequence is in 4 shown. After the yarn 3 has been severed and/or after the yarn end 14 on the bobbin side has passed the yarn monitor 15, the winding speed is reduced to a standstill. As shown in the exemplary embodiment shown, the yarn end 14 on the spool side comes to a standstill before it runs onto the surface of the spool 8 . In the 4 The position of the yarn end 14 on the bobbin side shown is called the pick-up position. The pick-up position is arranged essentially in the middle of the sleeve 7 or the coil 8 . The deviation F caused by the yarn defect is wound up on the surface of the bobbin 8 in the area of the at least parallel winding PW. In addition, the spinning unit 4 can stop the production of the yarn 3 and then the take-off speed can be reduced to a standstill. The yarn 3 produced after the yarn 3 has been severed can be sucked off with the aid of the intermediate store 12 . The stop sequence is then ended.

Following the stopping sequence, the yarn end 14 on the bobbin side can be prepared for piecing. For this purpose, the yarn end 14 on the spool side is picked up at the pick-up position with the aid of the workplace’s own resources and/or with the aid of a service robot, the at least one parallel winding PW is unwound from the spool 8, the deviation F caused by the yarn error is removed and the spinning unit 4 is returned. After piecing, work station 1 can resume normal operation.

The present invention is not limited to the illustrated and described embodiments. Modifications within the scope of the patent claims are just as possible as a combination of the features, even if they are shown and described in different exemplary embodiments.

Reference List

1

place of work

2

trigger device

3

yarn

4

spinning unit

5

quality sensor

6

spooling device

7

sleeve

8th

Kitchen sink

9

yarn guide element

10

oscillating device

11

control unit

12

cache

13

twine cutter

14

Bobbin end of yarn

15

yarn guard

cb

oscillating width

SB

winding width

f

yarn defect-related deviation

S

yarn loop

pw

parallel winding

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102015110486 A1 [0003]

Claims (11)

Method for operating a work station (1) of a spinning machine, - wherein a yarn (3) is drawn off from a spinning unit (4) at a take-off speed during normal operation, - wherein the yarn (3) is measured with the aid of a quality sensor (5) with regard to at least one yarn parameters is monitored, - the yarn (3) being wound onto a tube (7) at a winding speed with the aid of a winding device (6) and a coil (8) being formed in this way, - the yarn (3) being wound onto the tube (7) is moved back and forth along a traversing width (CB), and - whereby a stop sequence is initiated by the quality sensor (5) when a deviation (F) caused by a yarn defect from a target value of the at least one yarn parameter is detected, characterized in that during the stop sequence, the winding speed is reduced, with a Ga forms a loop (S). Method according to the preceding claim, characterized in that the traversing width (CB) is reduced during the reduction in the winding speed and/or thereafter. Method according to one of the preceding claims, characterized in that following the reduction in the winding speed and/or after the reduction in the traversing width (CB), the yarn (3) is severed in the region of the yarn loop (S), the resultant yarn end ( 14) is guided towards the spool (8) at the spooling speed. Method according to one of the preceding claims, characterized in that the yarn loop (S) is formed and/or severed in an intermediate store (12). Method according to one of the preceding claims, characterized in that the traversing width (CB) is reduced to approximately zero, as a result of which the yarn (3) runs onto the spool (8) in at least one parallel winding (PW). Method according to one of the preceding claims, characterized in that the at least one parallel winding (PW) runs centrally onto the coil (8). Method according to the preceding claim, characterized in that after the yarn (3) has been severed and/or after a yarn monitor (15) has detected the passage of the yarn end (14) on the bobbin side, the take-off speed and/or the bobbin speed is reduced to a standstill . Method according to one of the preceding claims, characterized in that the winding device (6) after the yarn monitor (15) has detected the passing of the yarn end (14) on the bobbin side continues to be operated until the yarn section with the deviation (F) caused by the yarn defect reaches the Surface of the coil (8) runs up and / or the coil-side yarn end (14) is arranged at a pick-up position. Work station (1) of a spinning machine, - with a take-off device (2) for drawing off a yarn (3) from a spinning unit (4), - with a quality sensor (5) for monitoring the yarn (3) with regard to at least one yarn parameter, - with a Winding device (6) for winding the yarn (3) onto a tube (7), and - with a traversing device (10) for moving the yarn (3) back and forth along a traversing width (CB) during winding, characterized in that the workstation (1) has a control unit (11) or is operatively connected to a control unit (11) which is designed to operate the workstation (1) according to one or more of the preceding claims. Work station (1) according to the preceding claim, characterized in that the work station (1) has an intermediate store (12), preferably working pneumatically, for forming a yarn loop (S). Work station (1) according to one of the preceding claims, characterized in that the intermediate store (12) has a yarn cutting device (13) for cutting the yarn (3) in the area of the yarn loop (S).

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