Method for operating spinning station of rotor spinning machine and rotor spinning machine

Abstract

In a method for operating a spinning station (2) of a rotor spinning machine (1), a yarn (8) is produced by means of a spinning rotor (23), after an unexpected interruption of the production at the spinning station (2), the spinning rotor (23) is subjected to standard cleaning, and the yarn (8) is reconnected at the spinning station (2). At least one special cleaning condition is defined, and when the at least one condition occurs, the spinning rotor (23) is specially cleaned. The at least one condition comprises the occurrence of a predetermined yarn alarm and / or a predetermined number of yarn alarms and / or exceeding a predetermined yarn break rate and / or being below a predetermined splicing efficiency. When at least one condition occurs, a mechanically strengthened cleaning of the spinning rotor (23) is performed as a special cleaning. A corresponding rotor spinning machine (1) comprising a plurality of adjacently arranged spinning stations (2) has at least one cleaning device (16, 18) for cleaning a spinning rotor (23) and a control unit (19) for carrying out the method.

Description

[0001] The invention relates to a method for operating a spinning station of a rotor spinning machine, in which method yarn is produced by means of a spinning rotor, wherein, after an unexpected interruption of production at the spinning station due to yarn breakage, yarn clearer cutting or bobbin replacement, the spinning rotor is subjected to standard cleaning and the yarn is reconnected at the spinning station. In the method, at least one special cleaning condition is defined, and when at least one condition occurs, production at the spinning station is interrupted in a targeted manner and the spinning rotor is subjected to special cleaning. The invention also relates to a rotor spinning machine comprising a plurality of adjacently arranged spinning stations, each spinning station having a spinning device, the spinning device comprising a spinning rotor for producing yarn. In addition, the rotor spinning machine also comprises at least one cleaning device for cleaning the spinning rotor.

[0002] In the prior art, there are various embodiments of rotor spinning machines that include a cleaning device for cleaning the spinning rotor. For example, in known rotor spinning machines, the yarn is reconnected by a movable maintenance device after the yarn production is interrupted. Before the connection, the movable maintenance device cleans the rotor. For this purpose, the movable maintenance device has a cleaning device, which includes a cleaning head, and the cleaning head includes cleaning elements such as scrapers and brushes. In order to clean the spinning rotor, the maintenance device is positioned in front of the relevant spinning device, the spinning device is opened, the cleaning head is aimed at the spinning rotor and cleaned. This maintenance device including a cleaning device has been disclosed in, for example, DE 102 31 484 A1. Since the maintenance device must first be placed in front of the spinning station, the rotor cleaning is relatively time-consuming. For example, DE 27 35 311 A1 also discloses the pneumatic cleaning of the spinning rotor by means of a cleaning device provided in the spinning station. For this purpose, one or more cleaning holes are provided in the 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, as soon as, for example, a yarn monitor registers a yarn break, a corresponding valve is triggered. Finally, the applicant's rotor spinning machine R 70 discloses that in the event of a yarn clearer cut, the rotor is cleaned by a pneumatic cleaning device arranged at the spinning station and comprising at least one blow nozzle. The spinning station is designed as a so-called self-contained spinning station, which can independently reconnect the yarn after an interruption of the spinning process, whether due to a yarn break or a yarn clearer cut. The spinning station can be reconnected very quickly by means of the spinning station's own pneumatic cleaning device, without unnecessary waiting times. When the production at the spinning station was interrupted unexpectedly because of yarn breakage or yarn clearer cutting, the rotor was always cleaned. It is also disclosed that the spinning rotor will be specially cleaned when certain specific situations occur. For example, according to DE 25 46 436 A1, cleaning is also performed after a certain operating time. For this purpose, the spinning station is stopped in a targeted manner, i.e. without waiting for a yarn break or the like to occur, which would in any case require a production interruption. This special cleaning is therefore also referred to as preventive cleaning. In the same way as standard cleaning after a yarn break, special cleaning is performed by means of a mobile maintenance device. A similar description is also found in DE 33 08 248 A1. Despite this preventive cleaning, accidental contamination of the rotor can still occur, with the resultant loss of yarn quality and productivity at the spinning station. The object of the present invention is therefore to provide a method for operating a spinning station, by which a yarn quality that is as constant as possible and a high productivity of the spinning station can be achieved, and also to specify a corresponding rotor spinning machine.

[0003] This object is achieved by a method for operating a spinning station of a rotor spinning machine and a rotor spinning machine having the features of the independent patent claims.

[0004] In the method for operating a spinning station of a rotor spinning machine, yarn is produced by means of a spinning rotor, wherein after an unexpected interruption of production at the spinning station, the spinning rotor is subjected to standard cleaning and the yarn is reconnected at the spinning station. At least one condition for special cleaning is defined, and when the at least one condition occurs, the spinning rotor is subjected to special cleaning. An unplanned production interruption is understood here to be an interruption caused by a yarn break or a yarn clearer cut. In the method, it is now suggested that at least one condition includes the occurrence of a predetermined yarn alarm and / or a predetermined number of yarn alarms and / or exceeding a predetermined yarn breakage rate and / or falling below a predetermined twisting efficiency, and when at least one of the conditions occurs, the spinning rotor is subjected to mechanically enhanced cleaning as special cleaning.

[0005] A yarn alarm is understood to be the cumulative occurrence of specific yarn faults, as a result of which the relevant spinning station is blocked and a fault message requiring intervention by a specialist is issued. The frequent occurrence of specific yarn faults may indicate a systemic fault in the spinning station. The spinning station cannot eliminate such a yarn alarm by itself. This is to be distinguished from simple yarn faults, which occur only once or never in a specific time relationship. Such simple yarn faults can be eliminated by the spinning station itself even if they occur several times by cleaning the yarn in the spinning station and then connecting the yarn again. Yarn alarms requiring intervention by a specialist are also triggered if the characteristics of a spinning station deviate significantly from those of other spinning stations. The term "splicing efficiency" basically means what percentage of all splicing operations at a spinning station were successful. However, the details of the calculation of the splicing efficiency vary depending on the customer or spinning mill and depending on the application. For example, in the first case, the term "splicing efficiency" can mean what percentage of all splicing operations at the first splicing attempt at a spinning station were successful. Likewise, in another case, for example for a different customer or application, the splicing efficiency can also mean what percentage of all splicing operations at the latest at the second (or further) splicing attempt at a spinning station were successful. Finally, the term "splicing efficiency" can also refer to a complete splicing sequence with several splicing attempts. In rotor spinning machines, a certain maximum number of splicing attempts is usually carried out in sequence. For example, five splicing attempts are usually carried out at a certain spinning station. If even the fifth attempt is unsuccessful, the relevant spinning station is set to fault. In this case, a splicing sequence includes a maximum of five splicing attempts. In this case, the splicing efficiency can also mean the percentage of successful splicing in all splicing sequences. By defining conditions, special cleaning can be carried out in a targeted manner at the spinning station as required. Special cleaning is only carried out if one or more yarn alarms are evaluated or if certain conditions occur that indicate a high degree of contamination on the spinning rotor. Only in this case is a mechanically intensive cleaning, which takes a longer time, carried out. In all other cases, only standard cleaning is carried out so that the spinning station can be quickly connected to the yarn again and non-productive downtimes are avoided. By defining at least one of the above conditions, it is also possible to avoid interruptions to production for cleaning when the rotor is not dirty and to avoid unnecessarily long downtimes at the spinning station. This can increase the productivity of the spinning station. By means of mechanical intensive cleaning, even stubborn dirt can be removed from the spinning rotors, which cannot usually be removed by standard cleaning. This improves the yarn quality and prevents problems in the spinning station, which could also lead to downtimes in the spinning station. In addition, the tendency to yarn breakage can be reduced and the splicing quality can be improved by mechanical rotor cleaning, which is performed at least from time to time. Finally, mechanical rotor cleaning can also be performed before the spinning station requires operator intervention when at least one condition occurs. It may be possible to ultimately solve the problem of the spinning station by intensive cleaning, thereby avoiding operator intervention. As a result, the number of operator interventions and the associated downtime of the spinning station can be reduced.

[0006] The rotor spinning machine comprises a plurality of adjacently arranged spinning stations, each of which has a spinning device, the spinning device comprising a spinning rotor for producing yarn, and the rotor spinning machine has at least one cleaning device for cleaning the spinning rotor. A control unit for executing the method is provided. As described above for the method, at least one condition is stored in a control unit of the rotor spinning machine, which can be a central control unit or a station control system of a spinning station. Therefore, when this condition occurs, the control unit can automatically cause the rotor spinning machine to perform mechanical intensive cleaning. In this method, the occurrence of specific yarn defects, such as moiré defects, can be specified as a condition for mechanically enhanced cleaning. Depending on the type of defect and the application, this condition can be defined as a single occurrence or multiple occurrences of the defect. Other examples of such yarn alarms are yarn count deviations and repeated occurrences of long thick or thin spots. These also indicate a systematic malfunction in the spinning station.

[0007] Frequent yarn breaks can also indicate contamination of the spinning rotor. When a certain yarn break rate is exceeded, additional yarn faults and yarn breaks, which lead to unproductive downtimes, can be avoided by mechanically intensive cleaning. A reduced splicing result also indicates contamination of the spinning rotor. The splicing efficiency is usually recorded continuously, so that conclusions can also be drawn from this about the degree of contamination of the spinning rotor. Below a certain splicing efficiency, the number of successful splices can be increased by mechanical intensive cleaning, which can also avoid unproductive downtimes. When at least one condition occurs, a mechanically intensive cleaning of the spinning rotor is thereby forced, which would not otherwise be carried out. In the method, it is advantageous that the magnitude of the predetermined yarn breakage rate and / or the predetermined splicing efficiency is set before production begins, in particular according to the current application. For example, in high-quality applications, only a small number of yarn defects can be accepted, and therefore only a lower yarn breakage rate can be accepted accordingly, but the downtime caused by more frequent mechanical intensive cleaning can be accepted. In this case, the predetermined yarn breakage rate will be determined to be a relatively low value. On the contrary, for simpler applications, a higher yarn breakage rate that results in more splicing work on the bobbin can of course be accepted. Since the starting limit for mechanically intensive cleaning can be freely adjusted, different production priorities can also be set. If the production priority is productivity, more yarn defects can be accepted and correspondingly production-reducing downtimes due to rotor cleaning are avoided as much as possible. On the other hand, if the production priority is yarn quality, high yarn breakage rates and many splices on the bobbin are unacceptable.

[0008] It is also advantageous if the type of yarn alarm and / or the number of yarn alarms are set before production starts, in particular according to the current application. This also allows for different production priorities to be taken into account. The permissible type and / or number of yarn alarms can also be adjusted depending on the fiber material. It is particularly advantageous if at least one further condition for special cleaning is defined, wherein the at least one further condition comprises reaching a predetermined yarn length and / or reaching a predetermined production time and / or reaching a predetermined fiber throughput and / or reaching a predetermined number of yarn defects and / or type of yarn defects. It can thus be provided, for example, that when a yarn alarm occurs, intensive cleaning is not yet performed. However, if a certain additional production time has elapsed, intensive cleaning is performed. The predetermined production time can be the time of the start of a batch or the time of the last intensive cleaning or other maintenance. It is also advantageous if, at the instigation of the operator, the spinning rotor is further subjected to special cleaning. This can be independent of whether at least one predefined condition occurs at the spinning station and is therefore also of inventive significance. Thus, in the event of a yarn alarm, the operator is summoned to the spinning station in any case. Even if the occurring yarn alarm itself does not yet trigger special cleaning, the operator can initiate special cleaning if he deems it reasonable to do so due to the occurrence of a yarn alarm. Of course, the operator can also initiate intensive cleaning based on other situations and events at the spinning station that he deems unrelated to the yarn alarm. Advantageously, the standard cleaning includes pneumatic cleaning of the spinning rotor. This can be done very quickly and is usually sufficient to quickly and reliably reconnect the spinning station after a yarn break or a yarn clearer cut. For this purpose, the rotor spinning machine has at least one pneumatic cleaning device for standard cleaning. Therefore, it is also particularly advantageous to carry out standard cleaning by means of a cleaning device which is provided by the spinning station itself. This prevents unavoidable non-productive downtimes due to waiting for mobile maintenance equipment. The cleaning device which is provided by the spinning station itself is preferably designed to be pneumatic. In rotor spinning machines, each spinning station has a cleaning device which is provided by the spinning station itself, in particular a pneumatic cleaning device, for standard cleaning. Furthermore, it is advantageous if the rotor spinning machine has at least one mechanical cleaning device for special cleaning.

[0009] It is advantageous if the mechanical intensive cleaning is carried out by means of a movable maintenance device. Since the mechanical intensive cleaning is only carried out under certain conditions, which in any case results in a downtime of the spinning station, any waiting time for the maintenance device is acceptable. For this purpose, a mechanical cleaning device is arranged in a maintenance device that is movable along the spinning station in the rotor spinning machine. As a result, the rotor spinning machine can be designed to be both structurally simple and economical. But according to a kind of alternative embodiment, also can carry out intensive cleaning by another cleaning device that the spinning station carries.In this case, be arranged with independent mechanical cleaning device at each spinning station.So just can avoid the waiting time of movable maintenance equipment. It is also advantageous to reconnect the yarn using the spinning station's own piecing device. In this case, the spinning stations of the rotor spinning machine are designed to be self-sufficient and can clean the rotor at least after the yarn clearer cuts and reconnect the yarn independently. This eliminates waiting times for mobile maintenance equipment, which would impair machine efficiency. In rotor spinning machines, each spinning station has its own piecing device for this purpose. Other beneficial effects of the present invention will be described in the following embodiments. In the accompanying drawings: Figure 1 shows a schematic front view of a rotor spinning machine according to a first embodiment; Figure 2 shows a schematic front view of a rotor spinning machine according to a second embodiment; Figure 3 shows a schematic side view, partially in section, of a spinning station of a rotor spinning machine according to a first embodiment; Figure 4 A schematic side view, partly in section, shows a spinning station of a rotor spinning machine according to a second embodiment; and Figure 5 A schematic side view of a spinning station of a rotor spinning machine with a front-mounted movable maintenance device is shown in partial section. In the following description of the figures, identical and / or at least comparable features are given the same reference numerals in the various figures. Individual features, their design and / or mode of action are usually only described in detail when first mentioned. If an individual feature is not described in detail again, its design and / or mode of action corresponds to the design and mode of action of the already described features with the same effect or the same name. In addition, for the sake of clarity, usually only one or a few of a plurality of identical components or features are marked. Figure 1 A schematic front view of a rotor spinning machine 1 according to a first embodiment is shown. The rotor spinning machine 1 has a plurality of adjacently arranged spinning stations 2, of which only two are indicated here. Each spinning station 2 is arranged between two frames 3, usually on two longitudinal sides of the rotor spinning machine 1. Each spinning station 2 has a feeding device 4 for feeding a fiber material 22 into a spinning device 7. In the spinning device 7, a yarn 8 is spun from the fiber material 22, the yarn is drawn out by a drafting device 9 and then fed to a winding device 12, where the yarn is wound onto a bobbin 13. In this case, the yarn also passes through a paraffinizing device 11 during this process. In order to control the functions of the rotor spinning machine 1 and / or the spinning stations 2, the rotor spinning machine 1 further has a central control unit 19. In addition, according to this example, each spinning station 2 also has its own control unit, i.e., a station control system 20.

[0010] In this example, a yarn monitoring device 10 is arranged below the drafting device 9 at each spinning station 2, by means of which the yarn 8 can be checked for yarn defects, such as thin spots, thick spots, moiré defects and other yarn defects. If a yarn defect is detected by the yarn monitoring device 10, the yarn monitoring device 10 triggers a so-called yarn clearer cut. The running yarn is then cut off, the defective yarn that has been wound onto the bobbin is unwound in the opposite direction to the normal winding direction, cut off again and fed out. The yarn defect is then cut off and the yarn 8 can be reconnected. Similarly, after a yarn break, the yarn end that has also been wound onto the bobbin must be found, unwound and reconnected. Yarn clearer cuts and yarn breaks are unexpected production interruptions in the process and their occurrence cannot be predicted. Reliable cleaning of the spinning rotor is very important for piecing operations, otherwise the piecing operation will not be successful. In addition, even if the piecing operation is successful, residual contamination in the spinning rotor may cause yarn defects. Therefore, the rotor cleaning is usually carried out before piecing. In principle, this can be done by the cleaning device 16 (see Figure 3 ), or by being arranged on a maintenance device 21 movable along a plurality of spinning stations 2 (see Figure 2 ) is cleaned by the cleaning devices 16 and 18. Figure 2 Another embodiment of a rotor spinning machine 1 is shown, with Figure 1 Unlike the rotor spinning machine 1 in FIG. 1 , the rotor spinning machine has a maintenance device 21 that can be moved along the spinning station 2. As shown by the dotted line, the movable maintenance device 21 also has a control unit 19, which is connected to the central control unit 19 of the rotor spinning machine 1. In addition, the movable maintenance device 21 also has a mechanical cleaning device 18 for performing rotor cleaning. As for the other parts, the rotor spinning machine 1 is similar to Figure 1 Therefore, they are not described in detail here. In a modern rotor spinning machine 1, the spinning stations 2 are designed as so-called self-contained spinning stations 2, which can independently perform piecing operations at least after the yarn clearer cuts, and each spinning station 2 is provided with a cleaning device 16 of the spinning station itself. Figure 3 and Figure 4 Such a self-contained spinning station is shown. Figure 3 The schematic diagram of a spinning station 2 of a rotor spinning machine 1 according to a first embodiment is shown in a partially sectional side view. It can be seen here that the fiber material 22 is fed via a feeding device 4 into a spinning device 7, from which it is fed into a spinning rotor 23, the spinning device comprising a feeding roller 5 and an opening roller 6. The various working components of the spinning station are already shown in FIG. Figure 1 As described in , each working device has its own drive 15, so each spinning station 2 can be operated independently of each other. For this purpose, the working devices, here the feed rollers 5, the opening rollers 6, the spinning rotor 23, the yarn monitoring device 10, the drafting device 9 and the winding device 12 or its drive 15 are controllably connected to the station control system 20, which in turn is connected to the central control unit 19 of the rotor spinning machine 1. The spinning station 2 further has a spinning station-owned piecing device (not shown) for independently performing the splicing operation. This includes at least one device for returning the yarn end to the spinning rotor 23, and preferably has a device for yarn end preparation. According to the present example, each spinning station 2 also has a pneumatic cleaning device 16 of its own for cleaning the rotor. The cleaning device 16 of the spinning station itself comprises a blowing nozzle 17, which in the present example is arranged in a cover element 14, which closes the spinning device 7 during operation. The cover element 14 is pivotably mounted at the spinning station 2 in a manner known per se. 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 open the cover element 14, a connector 24 is further provided on the compressed air line 26.

[0011] As described above, after an unexpected interruption of production due to a yarn clearer cut or yarn break, the cleaning device 16 of the spinning station, here a pneumatic cleaning device, performs a standard cleaning of the spinning rotor 23. The cleaning device 16 of the spinning station can be used to clean the rotor relatively quickly, since for this purpose only a valve (not shown) of the cleaning device 16 must be operated to trigger the air pulse. Production losses caused by downtime of the spinning device 7 during rotor cleaning can thus be kept to a minimum. Yet, standard cleaning by the cleaning device 16 that the spinning station carries itself is not always able to reliably remove all pollution.Equally, under specific fiber materials or specific conditions, also may cause the pollution that can not be removed by standard cleaning. Therefore, it is recommended to immediately carry out mechanical intensive cleaning of the spinning rotor by means of the mechanical cleaning device 18 when one or more specific conditions occur. The rotor groove is intensively cleaned by intensive cleaning to remove any attachments. Intensive cleaning is only carried out when there is a need, which is recognized by the occurrence of one or more defined conditions. At least one condition includes, for example, the occurrence of a predetermined yarn alarm and / or a predetermined number of yarn alarms and / or exceeding a predetermined yarn breakage rate and / or falling below a predetermined splicing efficiency. By mechanical intensive cleaning, on the one hand, the quality of the yarn 8 can be improved, and on the other hand, since mechanical intensive cleaning is only carried out when necessary, production losses caused by downtimes of the spinning station 2 can be kept at a low level. Preferably, the operator can determine in the central control unit 19, or particularly preferably in the station control system 20 of the relevant spinning station 2, which condition or conditions should trigger the mechanical intensive cleaning, depending on the specific situation of the spinning station. Here, the occurrence of multiple events can also be combined to determine one condition. The operator can also determine in the conditions in the control unit 19 and / or the station control system 20 whether a certain event (such as the occurrence of a specific yarn alarm) only needs to occur once or multiple times to trigger the mechanical intensive cleaning. If at least one condition includes exceeding a predetermined yarn breakage rate or falling below a predetermined splicing efficiency, the operator can set the size of the yarn breakage rate or splicing efficiency in the control unit 19 and / or the station control system 20, starting from this value to promote mechanical intensive cleaning. Preferably, the limit value for triggering mechanical intensive cleaning at the spinning station can be freely set according to various conditions.

[0012] According to a first embodiment of the method, mechanically intensive cleaning is performed by a mechanical cleaning device 18 which is also arranged at the spinning station 2 . Figure 4 A schematic side view of a partly cutaway view of such a spinning station 2 is shown with a mechanical cleaning device 18 provided in the spinning station. In this case, the further cleaning device 18 is also arranged at the cover element 14, or more precisely, in an extension of the cover element 14. For example, the further cleaning device 18 can be designed as an extendable scraper, such as Figure 4 Shown here.

[0013] Alternatively, brushes or other mechanical cleaning elements are also conceivable. It is also not absolutely necessary for the further mechanical cleaning device 18 to be arranged at the cover element 14. The further cleaning device can also be arranged at the spinning station 2 so that it can be moved and fed to the spinning rotor 23. In this case, the cover element 14 must first be pivoted open in order to feed the further cleaning device 18 to the spinning rotor 23.

[0014] According to another embodiment of the method, mechanical intensive cleaning is performed by a mechanical cleaning device 18, which is arranged in a maintenance device 21 that can be moved along the spinning station 2 of the rotor spinning machine 1. The structure of such a rotor spinning machine 1 is as follows Figure 2 shown. Figure 5A schematic side view of a spinning station 2 of such a rotor spinning machine 1 with a movable upstream maintenance device 21 is shown. In this example, the cover element 14 of the spinning device 7 has been folded down for mechanical intensive cleaning. The cover element 14 can be pivoted open either by the maintenance device 21 or by the spinning station 2 itself. In this case, the mechanical cleaning device 18 is designed as a cleaning head that can be fed to the spinning rotor 23 and is also equipped with an extendable scraper. In the schematic diagram shown, the cleaning device 18 has been fed to the spinning rotor 23 and the scraper has been extended. In order to achieve optimal production, good yarn quality and winding quality at the same time, and to identify defects in the spinning station 2, it is advantageous if the conditions for triggering mechanical intensive cleaning can be determined in the control unit of the rotor spinning machine 1 or, if necessary, also in the station control system 20 for each spinning station 2. For example, these conditions can be determined by the operator himself. However, it is also conceivable that these conditions are stored in the article management system according to the specific application and notified to the control unit of the rotor spinning machine 1 or the station control system 20 at the start of mass production. By defining the conditions, time-consuming mechanical rotor cleaning is only performed when there is a high probability that the spinning rotor 23 is also heavily soiled. In contrast, with the preventive cleaning of the prior art, production may be interrupted for cleaning even if the rotor is not soiled at all, which reduces the productivity of the spinning station. It is also possible that the spinning rotor 23 is not cleaned despite a high degree of soiling, e.g. before a prescribed operating time has been reached, which may lead to problems with the yarn quality and the spinning station. These problems of the prior art are now avoided by the demand-controlled mechanical intensive cleaning of the spinning rotor 23 only when defined conditions occur. The invention is not limited to the embodiments shown and described. As long as it does not violate the teaching content of the independent claims, changes may also occur within the scope of the patent claims, such as any combination of the features, even if they are shown and described in different parts of the specification or claims or in different embodiments.

[0015] List of Reference Numerals 1Rotor Spinning Machine 2 Spinning stations 3 racks 4Feeding device 5 Feeding roller 6 loose rollers 7 Spinning device 8. Yarn 9 Drafting device 10 Yarn monitoring equipment 11 Paraffinization device 12 Winding device 13 bobbin 14 Cover plate components 15. Drive 16 Spinning stations with built-in cleaning device 17 Blowing nozzle 18 Mechanical cleaning device 19Control Unit 20-station control system 21Maintenance Equipment 22 Fiber materials 23 Spinning rotor 24 connectors 25 Compressed air source 26 Compressed air pipeline

Claims

1. A method for operating a spinning station (2) of a rotor spinning machine (1), in which method a yarn (8) is produced by means of a spinning rotor (23), After an unexpected interruption of production at the spinning station (2), the spinning rotor (23) is cleaned in a standard manner, and the yarn (8) is reconnected at the spinning station (2). At least one special cleaning condition is defined, and when the at least one condition occurs, the spinning rotor (23) is specially cleaned, characterized in that: The at least one condition includes the occurrence of a predetermined yarn alarm and / or a predetermined number of yarn alarms and / or exceeding a predetermined yarn breakage rate and / or being lower than a predetermined splicing efficiency, And when at least one condition occurs, the spinning rotor (23) is subjected to mechanically enhanced cleaning as special cleaning.

2. The method according to the preceding claim, characterized in that The predetermined yarn breakage rate and / or the predetermined splicing efficiency are set before production starts, in particular, according to current applications.

3. The method according to any one of the preceding claims, characterized in that The type of yarn alarm and / or the number of said yarn alarms are set before production starts, in particular according to the current application.

4. The method according to any one of the preceding claims, characterized in that At least one further condition for special cleaning is defined, wherein the at least one further condition comprises reaching a predetermined yarn length and / or reaching a predetermined production time and / or reaching a predetermined fiber throughput and / or reaching a predetermined number and / or type of yarn defects.

5. The method according to any one of the preceding claims, characterized in that Furthermore, the spinning rotor (23) is specially cleaned at the prompting of the operator.

6. The method according to any one of the preceding claims, characterized in that The standard cleaning includes pneumatic cleaning of the spinning rotor (23).

7. The method according to any one of the preceding claims, characterized in that The standard cleaning is carried out by means of a cleaning device (16) provided in the spinning station.

8. The method according to any one of the preceding claims, characterized in that The special cleaning is performed by means of a movable maintenance device (21).

9. The method according to any one of the preceding claims, characterized in that The yarn (8) is reconnected by means of a connecting device provided in the spinning station.

10. A rotor spinning machine (1) comprising a plurality of adjacently arranged spinning stations (2), each of the spinning stations having a spinning device (7), the spinning device comprising a spinning rotor (23) for producing yarn (8), the rotor spinning machine comprising at least one cleaning device (16, 18) for cleaning the spinning rotor (23) and a control unit (19) for executing the method as claimed in one of the preceding claims.

11. The rotor spinning machine (1) according to the preceding claim, characterized in that The rotor spinning machine (1) has at least one pneumatic cleaning device (16) for standard cleaning.

12. The rotor spinning machine (1) according to one of the preceding claims, characterized in that Each spinning station (2) has its own cleaning device (16) for standard cleaning, in particular a pneumatic cleaning device (16).

13. The rotor spinning machine (1) according to one of the preceding device claims, characterized in that The rotor spinning machine (1) has at least one mechanical cleaning device (18) for special cleaning.

14. The rotor spinning machine (1) according to one of the preceding device claims, characterized in that The mechanical cleaning device (18) is arranged in a maintenance device (21) which can be moved along the spinning station (2).

15. The rotor spinning machine (1) according to one of the preceding device claims, characterized in that The spinning stations (2) each have a spinning station-specific piecing device.

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