EP4215655A1 - Method for operating a spinning station of a rotor spinning machine and rotor spinning machine - Google Patents

Abstract

In a method for operating a spinning position (2) of a rotor spinning machine (1), in which a yarn (8) is produced by means of a spinning rotor (23) and the yarn (8) produced is monitored by means of a yarn monitoring device (10), upon detection of a yarn defect by the yarn monitoring device (10), the spinning position (2) is shut down and the yarn defect is removed from the yarn (8). A pneumatic cleaning of the spinning rotor (23) is then carried out at the spinning station (2) by means of a spinning station's own cleaning device (16) and the yarn (8) is re-spun at the spinning station (2). A specific length of yarn produced and/or a specific time interval is thereby established, as well as a maximum number of yarn defects within the length of yarn produced and/or the time interval. The number of yarn defects at least within the produced yarn length and/or the time interval is detected and if the maximum number of yarn defects within the produced yarn length and/or the time interval is exceeded, a mechanical intensive cleaning of the spinning rotor is carried out using at least one further cleaning device. A corresponding rotor spinning machine (1) has a control unit for carrying out the method.

Description

The present invention relates to a method for operating a spinning station of a rotor spinning machine, in which a yarn is produced by means of a spinning rotor and the yarn produced is monitored by means of a yarn monitoring device, with the spinning station being stopped by the yarn monitoring device when a yarn defect is detected and the yarn defect being removed from the yarn, the spinning rotor then being cleaned at the spinning station by means of a cleaning device belonging to the spinning station and the yarn being spun on again at the spinning station. The invention also relates to a rotor spinning machine with a large number of spinning positions arranged next to one another, each of which has a spinning device with a spinning rotor for producing a yarn, a yarn monitoring device for monitoring the yarn produced and a cleaning device for cleaning the spinning rotor, and with at least one further cleaning device for carrying out intensive mechanical cleaning of the spinning rotor.

Rotor spinning machines with cleaning devices for cleaning a spinning rotor have become known in the prior art in multiple designs. For example, rotor spinning machines are known in which, after an interruption in production, the thread is spun again by means of a movable maintenance device. Before piecing, the mobile maintenance device carries out a rotor cleaning. For this purpose, the mobile maintenance device has a cleaning device with a cleaning head with cleaning elements such as scrapers. To clean the spinning rotor, the maintenance device is positioned in front of the spinning device in question, opens it and places the cleaning head on it Closing the spinning rotor and cleaning it. Such a maintenance device with a cleaning device is from DE 102 31 484 A1 known. Due to the fact that the maintenance device has to be placed in front of the spinning station, rotor cleaning is comparatively time-consuming.

Furthermore, it is, for example, from the DE 27 35 311 A1 It is known to carry out the cleaning of the spinning rotor by means of a pneumatic cleaning device arranged on the spinning device. For this purpose, one or more cleaning holes are provided in a cover element of the spinning device, through which compressed air can be blown into the spinning rotor. The compressed air is supplied to the spinning device by the spinning machine, and the corresponding valves are triggered, for example, by a thread monitor as soon as it registers a thread breakage.

In the case of rotor spinning machines, it is also known to monitor the yarn produced for yarn defects by means of a yarn monitoring device. This is for example in the DE 10 2015 117 204 A1 described. If a yarn defect is detected by the yarn monitoring device, the relevant spinning position is brought to a controlled standstill and the yarn defect is removed by a so-called clearer cut. After such a controlled interruption of production, the DE 10 2015 117 204 A1 spin the described spinning position again automatically. Rotor cleaning is not necessarily provided there, but can be carried out by means of a blowing nozzle introduced into the rotor housing from the outside, which is then provided on a mobile maintenance device.

Finally, it is known from the applicant's R 70 rotor spinning machine to clean the rotor in the event of a clearer cut by means of a cleaning device arranged at the spinning station with at least one blowing nozzle. The spinning positions are designed as so-called self-sufficient spinning positions, which start spinning again independently after an interruption in the spinning process, be it due to a yarn break or a clearer cut can. Thanks to the spinning position's own cleaning device, the spinning position can start spinning again very quickly and without unnecessary waiting times.

However, it has been shown that yarn defects can occur more frequently at the spinning station despite rotor cleaning. It is therefore the object of the present invention to reduce the number of yarn defects.

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

In a method for operating a spinning position of a rotor spinning machine, a yarn is produced by means of a spinning rotor and the yarn produced is monitored by means of a yarn monitoring device. When a yarn defect is detected by the yarn monitoring device, the spinning position is stopped and the yarn defect is removed from the yarn. The spinning rotor is then cleaned at the spinning station by means of a cleaning device built into the spinning station and the yarn at the spinning station is re-spun.

The method now provides that a specific length of yarn produced is defined and that a maximum number of yarn defects within the specific length of yarn produced is defined. The number of yarn defects is then detected at least within the yarn length produced, i.e. more precisely during the production of the specific yarn length, and if the maximum number of yarn defects within the specific yarn length produced is exceeded, a mechanical intensive cleaning of the spinning rotor is carried out using at least one additional cleaning device.

Using this method and counting the yarn defects within the specific yarn length produced and/or the time interval, it is possible to detect an accumulation of yarn defects within a short time or within short intervals, which could be due to insufficient rotor cleaning. As soon as this is recognized, mechanical rotor cleaning can be carried out in a targeted manner using a further cleaning device, by means of which stubborn deposits and dirt in the rotor groove can also be removed, which often cannot be removed by purely pneumatic rotor cleaning.

The time-consuming, mechanical rotor cleaning is therefore only carried out when it is actually necessary due to the frequent occurrence of yarn defects. Although these can be removed again by the cleaning cuts, a new, very time-consuming attachment process is required after each cleaning cut. In addition, many piecings in the yarn adversely affect the quality of the yarn and can lead to unevenly wound bobbins with bulges. Because a mechanical rotor cleaning is carried out when yarn defects occur frequently, the yarn quality and the package quality can be improved. Furthermore, the mechanical rotor cleaning, which is carried out at least from time to time, also reduces the tendency to end breaks and improves the piecing quality.

As a rule, on the other hand, only the rapid rotor cleaning is carried out using the spinning station's own cleaning device. Rotor cleaning can therefore still be carried out quickly and downtimes at the spinning positions can be reduced as a result. The machine efficiency can thereby be improved.

Preferably, the spinning station's own cleaning device is a pneumatic cleaning device. The rotor cleaning can thus be very fast be performed. In principle, however, it would also be conceivable to provide a mechanical cleaning device as the cleaning device for the spinning station. This could then carry out a quick standard cleaning for each piecing and carry out a mechanical intensive cleaning as described above if yarn defects occur frequently. However, the mechanical intensive cleaning could also be carried out by means of a further cleaning device, which could be provided either at each individual spinning position or only once in a mobile maintenance device, as will be explained later.

By specifying a specific, produced yarn length, the permissible number of yarn defects can be specified independently of the current application, i.e. the current fiber material and yarn type, and quality requirements can thus be particularly well taken into account. As an alternative to the above-described definition of a specific length of yarn produced, a specific time interval and a maximum number of yarn defects within the time interval can also be defined according to another embodiment of the method. The number of yarn defects at least within the time interval is then detected and, if the maximum number of yarn defects within the time interval is exceeded, mechanical intensive cleaning is carried out. It is true that determining the number of yarn defects within a certain time interval is somewhat less precise, since the production speed is not taken into account. Nevertheless, the yarn quality and the package quality can also be improved in this way and the machine efficiency can be increased.

According to a second embodiment of the method, a specific minimum yarn length produced and/or a minimum time interval between two yarn defects is determined and the yarn length produced is recorded upon detection of the yarn defect and/or a point in time at which the yarn defect was detected. When falling below the minimum yarn length produced and/or the minimum At a time interval between two yarn faults, the spinning rotor is intensively cleaned mechanically by means of at least one further cleaning device.

It is also possible by means of this method to detect an accumulation of yarn defects within a short period of time, which could be due to insufficient rotor cleaning. In this case, as described above in the first embodiment of the method, a mechanical rotor cleaning is carried out in a targeted manner by a further cleaning device in order to remove contamination in the rotor groove. Here, too, the mechanical rotor cleaning is only carried out if this is necessary due to the frequent occurrence of yarn defects.

The same advantages as described above can also be achieved with this method, namely an improvement in the yarn quality and the package quality, an improvement in the piecing quality and a reduction in the thread breakage rate with simultaneously reduced downtimes with an improvement in the machine efficiency.

According to a development of the second embodiment of the method, the mechanical intensive cleaning is only carried out after the minimum yarn length produced and/or the minimum time interval between two yarn defects has been fallen below several times, with a maximum permissible number of times the minimum yarn length produced and/or the minimum time interval being undershot is specified. In this way, it can be ruled out that a complex, mechanical rotor cleaning is already carried out if a yarn defect has happened to occur twice in quick succession. For example, the mechanical intensive cleaning could only be carried out when the minimum yarn length produced and/or the minimum time interval is not reached for the third time, since only then is it assumed that yarn defects will occur frequently.

Preferably, both the minimum yarn length produced and/or the minimum time interval and the maximum permissible number for falling below the minimum yarn length produced and/or the minimum time interval can be specified by an operator and entered into a control unit of the rotor spinning machine, which can be either a central control unit or a work station controller of the spinning station.

Likewise, in the first execution of the method, the minimum yarn length produced and/or the time interval as well as the maximum number of yarn defects within the minimum yarn length produced and/or the time interval can be specified by an operator and stored in a control unit of the rotor spinning machine, which can be either a central control unit or a work station control.

According to an alternative embodiment, however, it is also possible with both methods for the minimum yarn length produced and/or the minimum time interval and the maximum permissible number for falling below the minimum yarn length produced and/or the minimum time interval or the produced yarn length and/or the time interval and the maximum number of yarn defects within the yarn length and/or the time interval to be specified by the manufacturer and permanently programmed in the respective control unit.

A rotor spinning machine with a large number of spinning stations arranged next to one another, each of which has a spinning device with a spinning rotor for producing a yarn, a yarn monitoring device for monitoring the yarn produced and a spinning station's own cleaning device for cleaning the spinning rotor, has a control unit for carrying out the method described above. Preferably is the spinning station's own cleaning device is a pneumatic cleaning device.

As described above for the two methods, the yarn length produced and/or the time interval and the maximum number of yarn defects within the yarn length produced and/or the time interval or the minimum yarn length or the minimum time interval and the maximum permissible number for falling below the minimum yarn length or the minimum time interval are specified in a control unit of the rotor spinning machine, which can be a central control unit or a work station control of the spinning station. In the case of a cleaner cut, the control unit can thus independently initiate the respectively provided type of rotor cleaning.

According to an advantageous embodiment of the rotor spinning machine, it also has at least one further cleaning device for carrying out mechanical intensive cleaning of the spinning rotor. This can be provided either at each individual spinning position or only once within a mobile maintenance facility.

According to a further development of the invention, the yarn defects are divided into several types of yarn defects and the yarn defects and/or the length of yarn produced upon detection of the yarn defects and/or the time of detection of the yarn defects are recorded separately for the multiple types. This makes it possible to carry out the targeted, mechanical rotor cleaning earlier in the case of certain yarn faults, which frequently occur with certain types of contamination of the spinning rotor.

It is also advantageous if the maximum number of yarn defects within the specific yarn length produced and/or the minimum yarn length produced between two of these yarn defects is specified for at least one type of yarn defect. For example, moiré errors are common when debris builds up at a specific location in the rotor groove have fixed. By separately detecting moiré errors and determining the maximum permissible number or the minimum yarn length produced, this contamination can be specifically removed by mechanical rotor cleaning. With other yarn defects, on the other hand, a higher number of yarn defects within the yarn length produced or a greater minimum yarn length between two yarn defects or falling below the minimum yarn length several times can be accepted before a complex mechanical rotor cleaning is carried out. The same applies to the definition of the maximum number of yarn defects within the specific time interval or to the definition of the minimum time interval between two of these yarn defects.

The multiple types of yarn defects may include, for example, moiré defects and yarn count defects.

It is also advantageous if the mechanical intensive cleaning is carried out by a further cleaning device of a maintenance device that can be moved along several spinning positions of the rotor spinning machine or, in the case of the rotor spinning machine, the further cleaning device is arranged in a maintenance device that can be moved along several spinning positions. In this case, the additional cleaning device only has to be provided once in the maintenance facility, so that the rotor pinning machine can be designed in a structurally simple and cost-effective manner. In this case, there may be waiting times until the maintenance device has positioned itself in front of the respective spinning station. However, since this is no longer necessary with every rotor cleaning, but only in certain cases, the effects on the machine efficiency are rather small overall.

According to an alternative embodiment, however, it is also possible for the intensive cleaning to be carried out by a further cleaning device belonging to the spinning station. In this case, each of the spinning positions is its own mechanical cleaning device arranged. Waiting times for the mobile maintenance facility can be avoided as a result.

It is therefore also advantageous if the yarn is re-spun by means of a spinning station's own piecing device. In this case, the spinning positions of the rotor spinning machine are designed to be self-sufficient and, at least after a clearer cut, can both clean the rotor themselves and spin the yarn again independently. There are therefore no waiting times for a mobile maintenance device, which would impair the efficiency of the machine.

Figur 1

eine schematische Vorderansicht einer Rotorspinnmaschine nach einer ersten Ausführung,

Figur 2

eine schematische Vorderansicht einer Rotorspinnmaschine nach einer zweiten Ausführung

Figur 3

eine schematische, teilweise geschnittene Seitenansicht einer Spinnstelle einer Rotorspinnmaschine nach einer ersten Ausführung,

Figur 4

eine schematische, teilweise geschnittene Seitenansicht einer Spinnstelle einer Rotorspinnmaschine nach einer zweiten Ausführung, sowie

Figur 5

eine schematische, teilweise geschnittene Seitenansicht einer Spinnstelle einer Rotorspinnmaschine mit einer davor platzierten, verfahrbaren Wartungseinrichtung.

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

figure 1

a schematic front view of a rotor spinning machine according to a first embodiment,

figure 2

a schematic front view of a rotor spinning machine according to a second embodiment

figure 3

a schematic, partially sectioned side view of a spinning position of a rotor spinning machine according to a first embodiment,

figure 4

a schematic, partially sectioned side view of a spinning position of a rotor spinning machine according to a second embodiment, and

figure 5

a schematic, partially sectioned side view of a spinning station of a rotor spinning machine with a movable maintenance device placed in front of it.

In the following description of the figures, the same reference symbols are used for features that are identical and/or at least comparable in the various figures. The individual features, their design and/or mode of action are usually only explained in detail when they are first mentioned. If individual features are not explained in detail again, their design and/or mode of action corresponds to the design and mode of action of the features already described that have the same effect or have the same name. 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 rotor spinning machine 1 according to a first embodiment. The rotor spinning machine 1 has a multiplicity of spinning stations 2 arranged next to one another, of which only two are designated in the present case. The spinning stations 2 are each arranged between two frames 3, usually on two longitudinal sides of the rotor spinning machine 1. Each of the spinning stations 2 has a feed device 4 for feeding a fiber material 22 to a spinning device 7 . In the spinning device 7, a yarn 8 is spun from the fiber material 22, which is drawn off by means of a take-off device 9 and fed to a winding device 12, where it is wound onto a spool 13. In the present example, the yarn also passes through a waxing device 11. To control the functions of the rotor spinning machine 1 and/or the spinning stations 2, the rotor spinning machine 1 also has a central control unit 19. Furthermore, according to the present illustration, each of the spinning stations 2 also has its own control unit for the spinning station, namely the work station controller 20 .

In the present case, a yarn monitoring device 10 is arranged below the take-off device 9 at each of the spinning positions 2, by means of which the yarn 8 can be checked for yarn defects such as thin and thick spots, moiré defects and other defects. Used by the yarn monitoring device If a yarn defect is detected, the yarn monitoring device 10 triggers a so-called clearer cut. The running yarn is cut, the faulty piece of yarn that has already run onto the spool is unwound in the opposite direction to the normal winding direction, cut again and removed. Then the yarn error is cut out and the yarn 8 can be spun again. A rotor cleaning is usually carried out before piecing. For this purpose, the spinning stations 2 each have their own cleaning device 16 (see figure 3 ), which is not shown here.

figure 2 shows another embodiment of a rotor spinning machine 1, which in contrast to the rotor spinning machine 1 of figure 1 has a maintenance device 21 that can be moved along the spinning positions 2. The mobile maintenance device 21 also has a control unit 19 which is connected to the central control unit 19 of the rotor spinning machine 1, as indicated by the dot-dash line. Furthermore, the movable maintenance device 21 has a further cleaning device 18 for carrying out a rotor cleaning. Otherwise, the rotor spinning machine 1 corresponds to that of figure 1 and is therefore not explained in more detail here.

figure 3 shows a schematic, partially sectioned side view of a spinning station 2 of a rotor spinning machine 1 according to a first embodiment. It can be seen here that the fiber material 22 is fed to the spinning device 7 and there to a spinning rotor 23 by means of the feed device 4, which includes a feed roller 5 and an opening roller 6. The present spinning station 2 is also designed as a self-sufficient spinning station 2, which can carry out a piecing process independently, at least after a clearer cut. The individual working bodies of the spinning station, which already figure 1 have been described, each have their own drive 15, so that each spinning station 2 can be operated independently of the others can. For this purpose, the working elements, namely the feed roller 5, the opening roller 6, the spinning rotor 23, the yarn monitoring device 10, the take-off device 9, and the winding device 12 or their drives 15 are connected to the control unit 20, which in turn is connected to the central control unit 19 of the rotor spinning machine 1. For the independent implementation of a piecing process, the spinning station 2 also has a piecing device (not shown) belonging to the spinning station. This includes at least one device for returning the yarn end to the spinning rotor 32, for example a blowing unit.

Each of the spinning stations 2 also has its own spinning station cleaning device 16, which is pneumatic in the present case, for cleaning the rotor. The spinning station's own cleaning device 16 contains a blowing nozzle 17, which in the present case is arranged in a cover element 14 that closes the spinning device 7 during operation. The cover element 14 is arranged in a manner known per se on the spinning station 2 such that it can be swung away. The blowing nozzle 17 is connected to a compressed air source 25 via a compressed air line 26 . In order to be able to pivot the cover element 14, a coupling 24 is also provided in the compressed air line 26.

As previously described, as soon as a yarn defect has been detected by the yarn monitoring unit 10, a clearer cut is triggered. The yarn defect is cut out and the yarn 8 is then re-attached. In principle, the piecings meet the quality requirements for the yarn, so that they are generally not detected as a yarn defect. Nevertheless, each piecing forms a slub in the yarn. Problems can therefore arise if the yarn 8 contains too many piecings. On the one hand, the quality of the yarn 8 suffers, and on the other hand, with a large number of piecings wound onto the bobbin 13, the bobbins 13 may bulge. The number of piecings on the bobbin 13 should therefore not be too high. The aim is therefore to reduce the number of cleaner cuts and thus to reduce the number of piecings through regular rotor cleaning. For this reason, after a cleaning cut, the rotor is generally also cleaned by the spinning station's own pneumatic cleaning device 16 .

The rotor can be cleaned comparatively quickly by means of the spinning station's own cleaning device 16, since, for example, in the case of a pneumatic cleaning device 16, only a valve (not shown) of the cleaning device 16 has to be actuated to trigger a blowing blast. The production losses due to the spinning device 7 being idle during the cleaning of the rotor can be kept low as a result. Rapid standard cleaning of the spinning rotor 23 is also possible in the case of a spinning station's own mechanical cleaning device 16 . However, if the cleaning by the spinning station's own cleaning device 16 is insufficient or if the current application causes renewed contamination very quickly, further yarn faults can quickly occur despite the rotor cleaning that has been carried out. This increases the number of clearer cuts and thus also the number of piecings, as a result of which the quality of the yarn 8 and the bobbin 13 can be impaired.

It is therefore proposed to carry out a mechanical intensive cleaning of the spinning rotor by means of a mechanical cleaning device 16, 18 as soon as new yarn faults occur within a short period of time after piecing. The distances can relate both to yarn length distances and to time intervals. The rotor groove is intensively cleaned by the intensive cleaning and any adhesions are removed, so that accumulations of yarn faults can be avoided. If necessary, such an intensive cleaning can also be repeated, ie it can be carried out, for example, with three consecutive cleaning cuts. The operator in the central control unit can preferably do this 19 or the work station control 20 of the spinning station 2 in question. The mechanical rotor cleaning, which is only carried out when yarn defects occur more frequently, can improve the quality of the yarn 8 and the bobbin 13 and yet keep the production losses due to the idle times of the spinning station 2 low.

In order to detect an accumulation of yarn defects, a maximum permissible number of yarn defects within a specific yarn length produced can be established according to a first embodiment of the method. The yarn defects detected by the yarn monitoring device are registered and counted by the work station controller 20 or the central control unit 19 . If the maximum permissible number of yarn defects within the specific yarn length is exceeded, the control unit 19 or the work station control 20 initiates the intensive mechanical cleaning of the spinning rotor 23 . Instead of the specific yarn length produced, a specific time interval can also be specified within which only a specific number of yarn defects may occur.

Alternatively, it is also possible to specify a specific minimum length of yarn produced and/or a specific minimum time interval between two yarn defects. The yarn defects detected by the yarn monitoring device are registered by the work station controller 20 or the central control unit 19 and the yarn length produced is also recorded when the yarn defects are detected and/or the time at which the yarn defects are detected. The work station control 20 or the central control unit 19 compares the yarn length actually produced or the actual time interval between two yarn faults with the specified minimum yarn length or the specified minimum time interval. If the predetermined minimum yarn length and/or the predetermined minimum time interval is not reached, the intensive mechanical cleaning of the spinning rotor is initiated again.

According to a first embodiment of the method, the mechanical intensive cleaning is carried out by a further cleaning device 18 which is also arranged at the spinning station 2 . figure 4 shows a schematic, partially sectioned side view of such a spinning position 2 with a further cleaning device 18 belonging to the spinning position. The further cleaning device 18 can be designed, for example, as an extendable scraper, as here in figure 4 shown.

Alternatively, a brush or another mechanical cleaning element would also be conceivable. It is also not absolutely necessary for the further, mechanical cleaning device 18 to be arranged on the cover element 14 . It would also be possible to arrange the further cleaning device on the spinning position 2 such that it can be moved and fed to the spinning rotor 23 . In this case, the cover element 14 would first have to be swiveled away in order to deliver the further cleaning device 18 to the spinning rotor 23 .

Furthermore, it would also be conceivable for only a single, mechanical, spinning-station-specific cleaning device 16 to be arranged at the spinning station, which performs both standard cleaning for each piecing and, as described above, mechanical intensive cleaning if yarn defects occur frequently.

According to another embodiment of the method, the mechanical intensive cleaning is carried out by a further cleaning device 18 which is arranged in a maintenance device 21 which can be moved along the spinning positions 2 of the rotor spinning machines 1 . The structure of such a rotor spinning machine 1 is in figure 2 shown.

figure 5 shows a schematic, partially sectioned side view of a spinning station 2 of such a rotor spinning machine 1 with a movable maintenance device 21 placed in front of it. In the present example, the cover element 14 of the spinning device 7 has already been folded down to enable mechanical rotor cleaning. The pivoting of the cover element 14 can be done both by the maintenance device 21 and by the spinning station 2 itself. In the present case, the further cleaning device 18 is designed as a cleaning head which can be advanced to the spinning rotor 23 and which is also provided with retractable scrapers. In the illustration shown, the cleaning device 18 has already been delivered to the spinning rotor 23 and the scrapers have already been extended.

In order to achieve optimal production with good yarn and bobbin quality at the same time, it is advantageous if the parameters that define an accumulation of yarn defects can be defined in the control unit of the rotor spinning machine 19 or, if necessary, also individually for each spinning position 2 in the work station control 20. As already described, the parameters include the specific yarn length produced and/or the duration of the time interval and the maximum number of yarn defects or the minimum yarn length produced and/or the minimum time interval between two yarn defects and, if applicable, the permissible number of times the minimum yarn length produced and/or the minimum decency is not reached. Preferably, this can be specified by the user himself, but it is possible for this to be permanently programmed into the corresponding control unit 19 by the manufacturer. These parameters are particularly advantageously defined separately for different types of yarn defects. This also makes it possible, for example, to carry out a time-consuming, mechanical rotor cleaning only when the same yarn defect occurs more frequently.

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 features, too if they are shown and described in different embodiments.

Reference List

1

rotor spinning machine

2

spinning position

3

frame

4

feeding device

5

food roller

6

opening roller

7

spinning device

8th

yarn

9

trigger device

10

yarn monitoring device

11

paraffining device

12

spooling device

13

Kitchen sink

14

cover element

15

drive

16

spinning station's own cleaning device

17

air nozzle

18

further cleaning device

19

control unit

20

job control

21

maintenance facility

22

fiber material

23

spinning rotor

24

coupling

25

compressed air source

26

compressed air line

Claims (12)

Method for operating a spinning position (2) of a rotor spinning machine (1), in which a yarn (8) is produced by means of a spinning rotor (23) and the yarn (8) produced is monitored by means of a yarn monitoring device (10), when a yarn defect is detected by the yarn monitoring device (10), the spinning position (2) is stopped and the yarn defect is removed from the yarn (8), then at the spinning station (2) the spinning rotor (23) is cleaned by means of a preferably pneumatic cleaning device (16) belonging to the spinning station and the yarn (8) is re-spun at the spinning station (2), characterized in that that a specific length of yarn produced and/or a specific time interval is specified, that a maximum number of yarn defects is specified within the produced yarn length and/or the time interval, that the number of yarn defects is detected at least within the yarn length produced and/or the time interval and that if the maximum number of yarn defects is exceeded within the yarn length produced and/or the time interval, the spinning rotor (23) is subjected to intensive mechanical cleaning. Method for operating a spinning position (2) of a rotor spinning machine (1), in which a produced yarn (8) is monitored by means of a yarn monitoring device (10), wherein when a yarn defect is detected by the yarn monitoring device (10), the spinning station (2) is stopped and the yarn defect is removed from the yarn (8), then at the spinning station (2) the spinning rotor (23) is cleaned by means of a preferably pneumatic cleaning device (16) belonging to the spinning station and the yarn (8) is re-spun at the spinning station (2), in particular according to the previous claim, characterized, that a certain minimum length of yarn produced and/or a certain minimum time interval between two yarn defects is specified, that the length of yarn produced is recorded upon detection of the yarn defects and/or a point in time at which the yarn defects were detected, and that if the minimum produced yarn length between two yarn defects and/or the minimum time interval between two yarn defects is not reached, a mechanical intensive cleaning of the spinning rotor (23) is carried out. Method according to the preceding claim, characterized in that the mechanical intensive cleaning is only carried out after the minimum yarn length produced and/or the minimum time interval between two yarn defects has been undershot several times, with a maximum permissible number of times the minimum yarn length produced and/or the minimum time interval being undershot is specified. Method according to one of the preceding claims, characterized in that the yarn defects are divided into several types of yarn defects and the number of yarn defects and/or the yarn length produced upon detection of the yarn defects and/or the time of detection of the yarn defects for the multiple types are recorded separately. Method according to one of the preceding claims, characterized in that at least for one type of yarn defect, the maximum number of this yarn defect within the specific yarn length produced and/or the time interval and/or the minimum yarn length produced and/or the minimum time interval between two of these yarn defects is specified. Method according to one of the preceding claims, characterized in that the yarn defect is a Moiré defect. Method according to one of the preceding claims, characterized in that the mechanical intensive cleaning of the spinning rotor (23) is carried out by means of at least one further cleaning device (18). Method according to one of the preceding claims, characterized in that the intensive cleaning is carried out by a further cleaning device (18) of a maintenance device (21) which can be moved along several spinning stations of the rotor spinning machine (1). Method according to one of the preceding claims, characterized in that the intensive cleaning is carried out by a further cleaning device (18) belonging to the spinning station. Method according to one of the preceding claims, characterized in that the yarn (8) is re-spun by means of a piecing device belonging to the spinning station. Rotor spinning machine (1) with a large number of spinning positions (2) arranged next to one another, each of which has a spinning device (7) with a spinning rotor (23) for producing a yarn (8), a yarn monitoring device (10) for monitoring the yarn produced (8) and a preferably pneumatic cleaning device (16) belonging to the spinning station for cleaning the spinning rotor (23) with a control unit for carrying out the method according to one of the preceding claims. Rotor spinning machine (1) according to the preceding claim, characterized in that the rotor spinning machine (1) has at least one further cleaning device (18) for carrying out mechanical intensive cleaning of the spinning rotor (23).

Images