METHOD FOR OPERATING A SPINNING STATION OF A SPINNING MACHINE, AND SPINNING MACHINE

Abstract

A method for operating a spinning station of a spinning machine includes, during a downtime of the spinning station, performing one or both of: driving and stopping the opening roller at least one time by means of an individual drive configured with the opening roller, or driving the opening roller at a minimum rotation speed by means of the individual drive.

Description

FIELD OF THE INVENTION

The present invention relates to a method for operating a spinning station of a spinning machine, in which a fiber material is opened into individual fibers by means of an opening unit and the individual fibers are spun into a yarn by means of a spinning device. The opening unit includes an opening roller, which is rotatably mounted in an opening housing and is drivable by means of an individual drive. The spinning device is connected to a negative pressure channel of the spinning machine and acted upon by negative pressure, and the opening housing being connected to the spinning device via a feed duct.

BACKGROUND

Opening rollers are known in various embodiments from the prior art and are used to open a fiber material into loose individual fibers, which fiber material has been presented to the spinning device and is in the form of a continuous sliver. In open-end spinning, only individual fibers can be processed and pieced onto an open end of the yarn. For this purpose, the rotatably driven opening rollers are provided with a card clothing, which extracts the individual fibers from the presented sliver and conveys the individual fibers to a feed duct, from where the individual fibers are supplied to the spinning device.

For various reasons, fibers can accumulate at the opening roller. The fibers cling at various points between the rotating opening roller and the walls of the opening roller housing surrounding the opening roller. This can slow down the movement of the opening roller and lead up to a complete blockage of the opening roller.

DE 34 17 567 A1 describes that individual fibers can travel past the end face of the opening roller, in particular due to the helical arrangement of the card clothing, and become clamped in the region between the end face of the opening roller and the housing wall situated opposite the end face. To avoid these problems, DE 34 17 567 A1 provides that an additional air flow is introduced into the opening roller housing, which blows the fibers back into the region of the card clothing.

DE 33 41 279 A1 also describes a suction effect between the end faces of the opening roller and the housing wall. To solve the problem, it is provided that a scraper collecting groove is provided at the wall of the opening housing situated opposite the end face of the opening roller.

Similarly, DE 23 29 223 A1 describes that an air flow through the opening roller housing arises despite lateral covers of the opening roller, which project over the card clothing. The air flow is caused by a pressure gradient between the fiber supply side and the fiber discharge side, which is connected to the fiber feed duct. An accumulation of fibers is also to be avoided here by means of a certain geometric shape.

One aspect that is common to the aforementioned publications is that the opening roller is driven together with the other opening rollers by a central drive via a machine-length tangential belt. These types of spinning machines usually include a service device, which is movable along the workstations and is frequently also used to clean the workstations. Individually driven opening rollers, each of which includes a separate drive motor, are predominantly used in present-day spinning machines, however.

An opening device of this type is known from DE 10 2006 033 971 A1. This publication deals with an accumulation of fibers that arises in the region of the sliver feed, in particular due to adhering trash, such as dust, neps or honeydew. To remove the accumulation of fibers, a blowing nozzle unit is to be installed in the circumferential surface of the opening roller housing surrounding the opening roller, in the region of a housing interstice between the opening roller and the feed cylinder. By means of the air flow that is activated as a result, the trash particles adhering there are detached. Nevertheless, such individually driven opening rollers can result in fibers accumulating, in particular in the region of the card clothing, and thus the opening roller becoming blocked.

SUMMARY OF THE INVENTION

A problem addressed by the present invention is that of providing a method for operating a spinning station of a spinning machine and an appropriate spinning machine, which avoids an accumulation of fibers and blockages at an individually driven opening roller. Additional objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

The problems are solved by a method and a spinning machine having the features described and claimed herein.

In a method for operating a spinning station of a spinning machine, in which a fiber material is opened into individual fibers by means of an opening unit and the individual fibers are spun into a yarn by means of a spinning device, the opening unit includes an opening roller, which is rotatably mounted in an opening housing and is drivable by means of an individual drive. The spinning device is connected to a negative pressure channel of the spinning machine and acted upon by negative pressure. The opening housing is connected to the spinning device via a feed duct.

In the method, it is provided that, during a downtime of the spinning station, the opening roller is driven briefly at least once and is stopped again by means of its individual drive. In an alternative embodiment of the method, it is provided that, during a downtime of the spinning station, the opening roller is driven at a minimum rotational speed by means of its individual drive. The minimum rotational speed is a rotational speed, which is reduced as compared to the operating speed of the opening roller and with which the opening roller can just barely be held in rotation. The present invention has determined that fibers that have become stuck, in particular, at the card clothing of the opening roller, can be detached already by setting one individually driven opening roller into motion one time. This is also possible when the opening roller is operated during a downtime of the spinning station at a minimum rotational speed that is greatly reduced as compared to its operating speed. With individually driven opening rollers, larger amounts of fibers can accumulate in the region of the card clothing, in particular during a longer downtime of a spinning station, since air containing fibers is constantly sucked in via the supply air openings in the opening housing even when the opening roller is stopped. The fibers contained in the air are retained by the card clothing of the stopped opening roller and accumulate there. These fibers can result in a slow down and even blockage of the opening roller and prevent a smooth restart of the spinning station.

By moving the opening roller, fibers can now be prevented from becoming stuck at the card clothing of the opening roller. Fibers adhering to the opening roller can also be detached before the accumulation of fibers results in blockages. For example, fibers can be detached from the opening roller in the region of the trash removal opening due to the effect of gravity and, if applicable, acting centrifugal forces, and discarded via the trash removal opening. Moreover, the fibers can be detached by exposing the fibers to a suction flow in the region of the feed duct, which connects the opening housing to the spinning device, as a result of which the fibers are also detached. A slow down or blockage of the opening roller can be effectively prevented as a result.

The same advantages can also be achieved with a spinning machine having a multitude of adjacently arranged spinning stations, each of which includes an opening unit for opening a fiber material into individual fibers and a spinning device for spinning the individual fibers into a yarn. The opening unit has an opening roller, which is rotatably mounted in an opening housing and is drivable by means of an individual drive, the spinning device being connected to a negative pressure channel of the spinning machine and acted upon by negative pressure, and the opening housing being connected to the spinning device via a feed duct. The spinning machine includes a control unit for carrying out the method according to one of the preceding claims. The control unit can be a control unit of the spinning station or a central control unit of the spinning machine. The method can also be carried out in cooperation with two or more control units. It is particularly advantageous that no additional structural measures are necessary, and so the spinning machine can be cost-effectively designed.

It is advantageous when the opening roller is driven counter to its regular direction of rotation during the downtime of the spinning station. Accidents resulting due to the opening roller rotating while the spinning station is stopped can be avoided as a result.

It is particularly advantageous when the opening roller is briefly driven and stopped again multiple times at predetermined time intervals. This is advantageous in particular during a longer downtime of the spinning station in order to avoid a larger accumulation of fibers.

It is also advantageous when the time intervals are set in a control unit of the spinning station and/or of the spinning machine. With the spinning machine, it is therefore advantageous when the opening roller is drivable at predetermined time intervals, the time intervals being settable in a control unit of the spinning station and/or of the spinning machine. As a result, the spinning station can automatically detach or prevent an accumulation of fibers that may form without operating personnel and without a movable service device.

It is particularly advantageous when the time intervals are set in an application-specific manner depending on the fiber material that is used or, at the spinning machine, are storable in the control unit and/or in a system control unit having an article management system in an application-specific manner depending on the fiber material that is used. As a result, it can be provided that driving is carried out more frequently, for example, in the case of fiber materials loaded with trash or coarser fiber materials, in order to manage the greater tendency for fiber to adhere.

It is also advantageous when the opening roller is additionally cleaned by means of a blast air stream, in particular a blast air stream from a spinning station-specific blowing nozzle. In the spinning machine, the spinning stations each have a spinning station-specific blowing nozzle for cleaning the opening roller. The detachment and/or the removal of fibers that have already been detached from the card clothing can be assisted by means of such a blowing nozzle.

It is advantageous when the blowing nozzle opens into the region of the trash removal opening in order to assist the removal of the detached fibers.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages of the invention are described in the following exemplary embodiments, wherein, schematically:

FIG. 1 shows a schematic front view of a spinning machine, as an overview representation,

FIG. 2 shows a spinning station of a spinning machine in a schematic, partially cut side view,

FIG. 3 shows a schematic, partially cut front view of a spinning station including an opening unit according to a first embodiment, and

FIG. 4 shows a schematic, partially cut front view of a spinning station including an opening unit according to a second embodiment.

DETAILED DESCRIPTION

In the following description of the alternative exemplary embodiments represented in the figures, the same reference signs are utilized for features that are identical or at least comparable in terms of their configuration and/or mode of operation. Provided the features are not described in detail again, their design and/or mode of operation correspond/corresponds to the design and mode of operation of the above-described features. For the sake of greater clarity, reference signs for previously described components have not been individually included in the figures.

In the following description of the figures, the same reference characters are used for features that are identical and/or at least comparable in each of the various figures. The individual features, their embodiment and/or mode of operation are explained in detail usually only upon the first mention thereof. If individual features are not explained in detail once more, their embodiment and/or mode of operation correspond/corresponds to the embodiment and mode of operation of the features that act in the same way or have the same name and have already been described. Moreover, for the sake of clarity, often only one or only a few of several identical components and/or features is/are labeled.

FIG. 1 shows a schematic front view of a spinning machine 1 in a schematic overview representation. The spinning machine 1 has a multitude of adjacently arranged spinning stations 2 in a manner known, per se, the spinning stations 2 being arranged between two frames 3 of the spinning machine 1. For the sake of clarity, only two spinning stations 2 are designated and their individual components labeled in the present case. Each of the spinning stations 2 includes an opening unit 4 for opening a fiber material 5, which has been supplied thereto, into individual fibers 6 (see FIG. 2). The individual fibers 6 are fed to a spinning device 7, in which the individual fibers 6 are spun into a yarn 8. The spun yarn 8 is then drawn out of the spinning device 7 and fed to a winding device 10, where it is wound onto a package 11.

The spinning machine 1 has a central control unit 9 for controlling the functions of the spinning machine 1 and/or the spinning stations 2. According to the present representation, the spinning stations 2 each also have a spinning station-specific control unit 9, which is connected to the central control unit of the spinning machine 1, as indicated by the dotted lines.

Optionally, the spinning machine 1 can also include a service device 22, which is movable along the spinning stations 2. The service device 22 also includes a control unit 9, which is connected to the central control unit 9 of the spinning machine, as is also indicated by a dotted line.

In modern spinning machines 1, the spinning stations 2 of which are designed as autonomous spinning stations 2 which can automatically carry out a piecing process also after a thread breakage, such service devices 22 are necessary only for carrying out a package change. Most of the other service actions, such as seeking a thread end traveling on the package, cleaning the spinning element, preparing the yarn ends, and the actual piecing can be carried out by the spinning stations 2 themselves, which include individually drivable handling units for this purpose. The present invention is preferably usable on rotor spinning machines 1 including such autonomous spinning stations 2, although the present invention can be used on any spinning machine 1 having an individually driven opening roller 15 (see FIG. 2).

FIG. 2 shows a spinning station of a spinning machine 1 in a schematic, partially cut side view. The spinning machine 1 is designed as a rotor spinning machine in the present case. As described with reference to FIG. 1, a fiber material 5 is fed to the spinning station 2. For this purpose, the spinning station 2 includes a feed roller 16, which feeds the fiber material 5 to the opening roller 15 of the opening unit 4, the opening roller 15 being rotatably mounted in an opening housing 13. The opening roller 15 is driven for this purpose by means of an individual drive 14. The fiber material 5 is opened by the opening roller 15 into individual fibers 6, which are then fed to the spinning device 7 via a feed duct 18. The feed duct 18 connects the opening housing 13 to the spinning device 7. The spinning device 7 includes a spinning rotor 12, which is arranged in a housing (not shown), to which negative pressure is applied. The spinning device 7, more precisely, the housing in this case, is connected to a negative pressure channel 17 for this purpose.

In the method, during a downtime of the spinning station 2, the opening roller is briefly driven and stopped again at least one time, preferably also multiple times, by means of its individual drive 14. The individual drive 14 of the opening roller 15 is connected for control purposes to the control unit 9 of the spinning station 2 for this purpose. The control unit 9 can control the repeated driving of the opening roller 15 at predetermined time intervals. For this purpose, the time intervals can be established in the control unit 9 of the spinning station 2 or also in the central control unit 9 of the spinning machine 1, for example, depending on an application of the spinning station 2. Alternatively to repeatedly driving the opening roller 15, it can also be provided that driving is carried out permanently during a downtime of the spinning station at a rotational speed that is reduced as compared to the operating speed of the opening roller. As a result, a larger accumulation of fibers, which can result in blockages of the opening roller, can be avoided and the smooth restart of the spinning station 2 can be ensured. This is explained in greater detail in the following with reference to FIGS. 3 and 4.

FIG. 3 shows a schematic, partially cut front view of a spinning station including an opening unit 4 according to a first embodiment. The feeding of the fiber material 5 by means of the feed roller 16 is shown. The fiber material 5 is opened into the individual fibers 6 by means of a card clothing 20 of the opening roller 15. The individual fibers 6 are also discharged by means of the card clothing 20 to the feed duct 18, from where the individual fibers 6 enter the spinning device 7 due to the effect of the negative pressure prevailing in the spinning device 7. The spinning device 7 is designed as a rotor spinning device in the present case and includes a spinning rotor 12 as a spinning element.

During operation of the spinning station 2, fiber material 5 is continuously fed to the opening unit 4 and the yarn 8 that has been spun from the fiber material 5 (see FIGS. 1 and 2) is continuously drawn out of the spinning device 7. In spinning machines 1, individual spinning stations 2 are often down for a longer period of time. This is the case, for example, when there is a disruption or a defect of the spinning station 2 or also when the relevant spinning station 2 has already reached its production target and a new product has not yet been started. Due to the negative pressure applied in the spinning device 7, air is drawn in, also during a downtime of the workstation 2, however, from the supply air openings, in particular the trash removal opening 23, in the opening housing 13 through the opening housing 13 via the card clothing 20 of the opening roller 15 into the spinning device 7. The fibers contained in the air cling to the card clothing 20 of the stopped opening roller 15, as a result of which an increasingly larger amount of fiber can accumulate over time.

If the opening roller 15 is now briefly driven at least one time, preferably multiple times, however, during the downtime of the spinning station 2, the accumulation of fibers can be effectively avoided. Due to the brief driving, individual fibers 6 can be prevented from clinging to the card clothing 20 and individual fibers 6 that are already adhering can be detached from the card clothing 20. The individual fibers are preferably detached from the card clothing 20 in the region of the trash removal opening 23 due to the effect of gravity and can be discharged via the trash removal opening 23. Individual fibers 6 in the region of the feed duct 18 can also be exposed to the effect of the negative pressure applied there, as a result of which the individual fibers 6 can be detached from the card clothing and discharged via the feed duct 18.

FIG. 4 shows a schematic, partially cut front view of a spinning station 2 including an opening unit 4 according to a second embodiment. In contrast to the embodiment according to FIG. 3, a spinning station-specific blowing nozzle 19 is arranged at the presently shown spinning station 2 for cleaning the opening roller 15. The blowing nozzle 19 is connected to a compressed air supply (not shown here) and is actuatable by means of a valve 21. The detachment of adhering individual fibers 6 from the card clothing 20 can be assisted by means of the blowing nozzle 19. Preferably, the blowing nozzle 19 is arranged for this purpose closely ahead of the trash removal opening with respect to the direction of rotation of the opening roller 15. The spinning device 7 is designed as a rotor spinning device including a spinning rotor 12 in this case as well. The invention is also usable at all other spinning machines 1, however, the spinning stations 2 of which have individually driven opening rollers 15.

The present invention is not limited to the represented and described exemplary embodiments. Modifications within the scope of the claims are also possible, as is any combination of the described features, even if they are represented and described in different parts of the description or the claims or in different exemplary embodiments, provided no contradiction to the teaching of the independent claims results.

LIST OF REFERENCE CHARACTERS

• • 1 spinning machine
  • 2 spinning station
  • 3 frame
  • 4 opening unit
  • 5 fiber material
  • 6 individual fibers
  • 7 spinning device
  • 8 yarn
  • 9 control unit
  • 10 winding device
  • 11 package
  • 12 spinning rotor
  • 13 opening housing
  • 14 individual drive
  • 15 opening roller
  • 16 feed roller
  • 17 negative pressure channel
  • 18 feed duct
  • 19 blowing nozzle
  • 20 card clothing
  • 21 valve
  • 22 service device
  • 23 trash removal opening

Claims

1-10: (canceled)

11. A method for operating a spinning station of a spinning machine, wherein the spinning machine includes:

an opening unit that opens a fiber material into individual fibers that are spun into a yarn by means a spinning device;

the opening unit including an opening roller rotatably mounted in an opening housing and drivable by an individual drive,

the spinning device connected to a negative pressure channel of the spinning machine and acted upon by negative pressure,

the opening housing connected to the spinning device via a feed duct;

the method comprising:

during a downtime of the spinning station, performing one or both of: driving and stopping the opening roller at least one time by means of the individual drive, or driving the opening roller at a minimum rotation speed by means of the individual drive.

12. The method according to claim 11, wherein the opening roller is driven counter to an operational direction of rotation during the downtime of the spinning station.

13. The method according to claim 11, wherein the opening roller (15) is repeatedly driven and stopped at predetermined time intervals during the downtime of the spinning station.

14. The method according to claim 13, wherein the time intervals are set in a control unit of the spinning station or a control unit of the spinning machine.

15. The method according to claim 13, wherein the time intervals are set in an application-specific manner depending on the fiber material being spun at the spinning station.

16. The method according to claim 11, further comprising additionally cleaning the opening roller with a bast air stream from a spinning station-specific blowing nozzle.

17. A spinning machine, comprising:

a plurality of adjacently arranged spinning stations, wherein each of the spinning stations comprises: an opening unit that opens a fiber material into individual fibers that are spun into a yarn by a spinning device; the opening unit including an opening roller rotatably mounted in an opening housing and drivable by an individual drive; the spinning device connected to a negative pressure channel of the spinning machine and acted upon by negative pressure; the opening housing connected to the spinning device via a feed duct;

the spinning machine or each spinning station further comprising a control unit configured to control the spinning stations to perform one or both of the following during a downtime of the spinning station: driving and stopping the opening roller at least one time by means of the individual drive, or driving the opening roller at a minimum rotation speed by means of the individual drive.

18. The spinning machine according to claim 17, wherein the opening roller is drivable at predetermined time intervals set by the control unit.

19. The spinning machine according to claim 18, characterized in that the time intervals are stored in the control unit and are application-specific depending on the fiber material being spun at the spinning station.

20. The spinning machine according to claim 18, wherein each spinning station further comprises a station-specific blowing nozzle for additional cleaning the opening roller.