DRAFTING DEVICE, SPINNING STATION AND METHOD

Abstract

A drafting device for a textile machine, in particular an air-jet spinning machine, wherein the drafting device can have a plurality of roller pairs which can be driven differently from one another. The roller pairs can be designed and arranged to guide a sliver between a top roller and a bottom roller of the roller pairs during their rotational operation in order to stretch the sliver. The drafting device can be designed and configured to carry out a piecing process after the sliver has been severed in the drafting device. In order to optimize a spinning process, it is provided that the drafting device is designed and configured to engage at least two roller pairs via their drive in a defined manner during the piecing process.

Claims

1. A drafting device for a textile machine comprising: a plurality of roller pairs which can be driven differently from one another, wherein the plurality of roller pairs are designed and arranged to guide a sliver between a top roller and a bottom roller of the plurality of roller pairs during a rotational operation thereof in order to stretch the sliver; wherein the drafting device is designed and configured to carry out a piecing method after severing of the sliver in the drafting device; and wherein the drafting device is designed and configured to engage at least two roller pairs of the plurality of roller pairs in a defined manner via a drive thereof in the piecing method.

2. The drafting device according to claim 1, wherein the at least two roller pairs for a defined engagement are selected from the following: an input roller pair; a center roller pair; and/or an apron roller pair.

3. The drafting device according to claim 1, further including a spinneret designed and configured to assume at least one cleaning position.

4. The drafting device according to claim 1, wherein the drafting device is designed and configured to sever the sliver by a coordinated engagement of at least one roller pair of the plurality of roller pairs.

5. The drafting device according to claim 1, wherein the drafting device is designed and configured to coordinate severing of the sliver with a transfer of a spinneret to a cleaning position via a coordinated engagement of at least one roller pair of the plurality of roller pairs.

6. The drafting device according to claim 1, wherein the drafting device is designed and configured to specifically adjust at least one process parameter for driving at least one of the roller pairs of the plurality of roller pairs over a defined period of time.

7. The drafting device according to claim 1, wherein the drafting device is designed and configured during a piecing ramp to form at least two support points in a ramp-up profile for a defined driving of at least one of the roller pairs of the plurality of roller pairs.

8. The drafting device according to claim 1, wherein the drafting device is designed and configured to maintain a defined temperature of a drive of one of the roller pairs of the plurality of roller pairs and/or of a rubber lining of rollers of one of the roller pairs of the plurality of roller pairs.

9. A spinning station comprising: at least one spinneret; at least one thread end preparer; and at least one thread take-off; wherein the at least one spinneret and the at least one thread end preparer are arranged and designed to initiate piecing; wherein the at least one thread take-off is arranged and designed to remove a thread from the at least one spinneret after a spinning process; and wherein at least one drivable roller pair of the plurality of roller pairs of the drafting device according to claim 1 is engaged in a coordinated manner via the drive of at least one roller pair of the plurality of roller pairs.

10. The spinning station according to claim 9, wherein the at least one thread take-off is designed and configured to be engaged along with the at least one roller pair in a coordinated manner, wherein a ramp-up profile of the at least one roller pair has a piecing ramp with at least two support points.

11. The spinning station according to claim 9, wherein: the at least one spinneret is designed and configured to assume at least an operating position and a cleaning position different therefrom; and the at least one thread end preparer is designed and configured to at least unravel a thread end by a compressed air supply.

12. A method comprising at least one of the steps of: severing a sliver by coordinated engagement of at least one roller pair of the drafting device according to claim 1; piecing by coordinated engagement of the at least two roller pairs of the drafting device; piecing by coordinated engagement of at least one thread take-off of a spinning station, the spinning station comprising at least one spinneret, at least one thread end preparer and the at least one thread take-off, wherein the at least one spinneret and the at least one thread end preparer are arranged and designed to initiate piecing, wherein the at least one thread take-off is arranged and designed to remove a thread from the spinneret after a spinning process, and wherein at least one drivable roller pair of the drafting device is engaged in a coordinated manner via the drive of the at least two roller pairs; and spinning the thread comprising a coordinated engagement of a thread take-off and the at least one roller pair of the drafting device.

13. A control apparatus designed and configured to carry out the method according to claim 12.

14. A textile machine comprising at least one of the following: a drafting device for a textile machine having a plurality of roller pairs which can be driven differently from one another, wherein the roller pairs are designed and arranged to guide a sliver between a top roller and a bottom roller of the roller pairs during their rotational operation in order to stretch the sliver, wherein the drafting device is designed and configured to carry out a piecing method after severing of the sliver in the drafting device, and wherein the drafting device is designed and configured to engage at least two roller pairs in a defined manner via their drive in the piecing method; a spinning station comprising: at least one spinneret, at least one thread end preparer, and at least one thread take-off, wherein the at least one spinneret and the at least one thread end preparer are arranged and designed to initiate piecing, wherein the at least one thread take-off is arranged and designed to remove a thread from the at least one spinneret after a spinning process, and wherein at least one drivable roller pair of a drafting device is engaged in a coordinated manner via the drive of the roller pairs; and a control apparatus designed and configured to carry out a method comprising at least one of the steps of: severing a sliver by coordinated engagement of at least one roller pair, wherein the drafting device has a plurality of roller pairs which can be driven differently from one another, wherein the roller pairs are designed and arranged to guide the sliver between a top roller and a bottom roller of the respective roller pairs during their rotational operation in order to stretch the sliver, and wherein the drafting device is designed and configured to carry out a piecing method after severing of the sliver in the drafting device, and wherein the drafting device is designed and configured to engage at least two roller pairs in a defined manner via their drive in the piecing method; piecing by coordinated engagement of at least two roller pairs of the drafting device; piecing by coordinated engagement of at least one thread take-off of a spinning station in order to return a thread end; and spinning a thread comprising a coordinated engagement of a thread take-off and the at least one roller pair of the drafting device according to claim 1.

15. A computer program product designed to perform a method comprising at least one of the steps of: severing a sliver by coordinated engagement of at least one roller pair of a drafting device, wherein the drafting device has a plurality of roller pairs which can be driven differently from one another, wherein the roller pairs are designed and arranged to guide a sliver between a top roller and a bottom roller of the roller pairs during their rotational operation in order to stretch the sliver, wherein the drafting device is designed and configured to carry out a piecing method after severing of the sliver in the drafting device, and wherein the drafting device is designed and configured to engage at least two roller pairs in a defined manner via their drive in the piecing method; piecing by coordinated engagement of at least two roller pairs of the drafting device; and piecing by coordinated engagement of the at least one thread take-off of the spinning station according to claim 9.

Description

[0092] In the following, exemplary embodiments of the invention are described in more detail with reference to figures, showing schematically and by way of example:

[0093] FIG. 1 a schematic representation of a piecing method;

[0094] FIG. 2A a view of a sliver position in one embodiment of a drafting device after a shutdown;

[0095] FIG. 2B a view of a start of the warm-up of an apron bottom roller and/or output bottom roller in an embodiment of a drafting device, wherein the sliver is severed;

[0096] FIG. 2C a view of a sliver position after the end of the warm-up of the apron bottom roller/output bottom roller in one embodiment of a drafting device;

[0097] FIG. 3A a view of a first cleaning position in one embodiment of a drafting device;

[0098] FIG. 3B a view of a second cleaning position in one embodiment of a drafting device;

[0099] FIG. 4 a schematic representation of a piecing ramp of an output bottom roller and a thread take-off;

[0100] FIG. 5 a schematic representation of a piecing ramp with a support point;

[0101] FIG. 6 a schematic representation of a piecing ramp with an S profile;

[0102] FIG. 7 a schematic representation of a piecing ramp with a support point; and

[0103] FIG. 8 a schematic representation of a piecing ramp with three support points.

[0104] The same reference signs are used for elements and structures having the same effect and/or of the same type.

[0105] FIG. 1 shows a schematic representation of a piecing method 100 on a textile machine, in particular an air-jet spinning machine. A catching of a thread end of a thread (also referred to as upper thread) deposited on a take-up bobbin can be configured in a step 1. In this step 1, the thread end can be caught by a movable thread end catching device such as a suction nozzle. Meanwhile, a thread take-off formed by a roller pair can be opened in order to allow the thread to be inserted into the thread take-off.

[0106] In a step 2 of placing a thread section of the thread, the thread can be inserted into the thread take-up, a so-called take-up, via deflection contours in the course of moving the thread end catching device. In particular, the take-up can be designed to take the thread. In particular, the thread is arranged, in particular at the end of the movement of the thread end catching device, in a cutting region of scissors and/or in front of an opening of an unraveling tube of a thread end preparer. The thread take-off clamps the thread, in particular after the thread end has been arranged as described above.

[0107] In a step 3, the thread can be cut using the scissors. A defined length of thread can be cut off.

[0108] In a step 4 of unraveling the thread end, the thread end can be unraveled by introducing a flow of compressed air into an unraveling tube.

[0109] In a step 5 of a first return of the thread to an outlet of a thread take-up channel of an air-jet spinneret, a first return of the thread can be supported by rotating back the take-up clamping the thread and by introducing an air flow accompanying the thread end or the thread into a thread guide channel guiding the unraveled thread end, wherein the thread guide channel can be a component of the thread end preparer and in particular can comprise or form the unraveling tube and furthermore preferably extends up to the outlet of the thread take-up channel of the air-jet spinneret. The spinning pressure can be used for air-accompanied transport within the thread take-off channel; alternatively or additionally, the thread can be blown further within the thread guide channel by a compressed air supply.

[0110] In a step 6 of laying a thread loop, in particular after the step 5 of the first return, the step 6 of laying the thread loop can take place in a pneumatic thread storage, which is arranged in the thread running direction between the air-jet spinneret and the take-up bobbin or the take-up bobbin holder for rotatably holding the take-up bobbin, in particular between the take-up and the take-up bobbin or the take-up bobbin holder. The thread storage can serve as compensation since the ramp-up times and accelerations of at least one of a drive shaft, a take-up bobbin, a drafting device 101, and/or a take-up can be different.

[0111] In a step 7 of combing out and keeping warm, in particular during the previously described steps 1 to 6, an output roller pair rotates by driving the output bottom roller 26 in order to comb out the sliver 31 arranged between the output rollers and in order to keep the output bottom roller drive 36 and/or the rubber lining of the output rollers warm.

[0112] In the case of a partially automated sliver feed, the above step 7 can in particular be adapted. In other words, in particular after step 6 or with step 7, the remaining roller pairs of the drafting device 101 (input roller pair, center roller pair(s) and, if present, apron roller pair) are engaged in a defined manner in order to start a defined drawing-in and stretching of the sliver. Before or at the latest with the start of the remaining roller pairs, the air-jet spinneret can be moved to a cleaning position (see the two variants described elsewhere) in order to be able to remove the old sliver. Subsequently, the roller pairs can be stopped, and the air-jet spinneret in particular resumes the operating position in order to continue the piecing process as described elsewhere, in particular by starting the drafting device 101 in a defined manner (see step 9). In this case, the stopping of the output bottom roller drive 36 described elsewhere can be omitted since the roller pairs of the drafting device 101 can already be stopped.

[0113] This can be supplemented by putting the apron roller pair into operation, in particular by driving the apron bottom roller, before the engagement of the remaining roller pairs of the drafting device 101 in order to achieve a severing of the sliver 31 in the region between the center roller pair and the apron roller pair. With the engagement of the apron roller pair, the air-jet spinneret in particular is moved to the cleaning position for removing the severed sliver section.

[0114] Additionally or alternatively, the speeds of the respective driven rollers of the respective roller pairs, in particular the driven bottom rollers, can be specifically adjusted over a defined period of time. In particular, the operation of a roller can have at least two support points during a ramp-up in a piecing ramp or in an acceleration ramp of a ramp-up profile of the roller. This is described in detail elsewhere.

[0115] In a step 8 of a second return, a second return of the thread follows in particular. In particular, this takes place right into a vortex chamber (also referred to as a spinning chamber) so that the thread end can be caught by the air flow.

[0116] In a step 9 of stopping the output roller pair, the rotation of the output rollers or the output roller pair is stopped. The drafting device 101 can subsequently be started depending on the input parameters.

[0117] The input parameters for the ramp-up, which define the ramp-up profile, can in particular be one of a lead time, a piecing speed, a speed profile, a speed for a first stage, a duration of operating a first stage, and/or a total ramp-up time of the drafting device 101. The driven apron bottom roller 24, center bottom roller 22, and/or input bottom roller 20 can follow the output bottom roller 26 in the ramp-up.

[0118] A speed profile that makes up the ramp-up profile can in particular have at least one of four sub-parameters. These can be selected from a speed for a first stage, a duration of operating a first stage, a total ramp-up time of the drafting device 101, and a thread take-up acceleration, which in particular determines the total ramp-up time of the thread take-up.

[0119] The thread end can be held in the spinning chamber during a dwell time of the thread take-off, which makes it possible to adjust the preparation of the drafting device 101 in a defined manner.

[0120] In a step 10 of dwelling for a dwell time, the thread take-off in particular ramps up at the end of its dwell time in accordance with a specified and/or entered acceleration.

[0121] In a step 11 of running in a running time of the thread take-off, the drafting device 101 also ramps up in particular during this time. Running is understood herein to mean the driven operation of the thread take-off. The thread is pulled out of the spinning chamber by means of the driven thread take-off after connection to the sliver 31 for continuous spinning of the thread, wherein the piecing process is completed in particular after the ramp-up times have elapsed.

[0122] FIG. 2A shows a view of a sliver position in one embodiment of a drafting device 101 after a shutdown of the illustrated bottom rollers 20, 22, 24, 26 of roller pairs, which are each composed of one of the bottom rollers 20, 22, 24, 26 and respectively assigned top roller in order to transport the intermediate sliver 31 in a closed state while the roller pairs are rotating, driven by the illustrated bottom rollers 20, 22, 24, 26. In particular, an input bottom roller 20 of an input roller pair, a center bottom roller 22 of a center roller pair, an apron bottom roller 24 of an apron roller pair, and an output bottom roller 26 of an output roller pair are shown in a row, which are part of the drafting device 101. The drafting device 101 is attached to a carrier 12 via a locking device 16. In particular, the input bottom roller 20 is rotationally driven by an input bottom roller drive 30. In particular, the center bottom roller 22 is rotationally driven by a center bottom roller drive 32. In particular, the apron bottom roller 24 is rotationally driven by an apron bottom roller drive 34. In particular, the output bottom roller 26 is rotationally driven by an output bottom roller drive 36. In particular, an apron 28 runs around the apron bottom roller 26 and can also be guided around an apron bridge 29 in order to build up tension in the aprons 28. The bottom rollers 20, 22, 24, 26 can be adjusted in their relative position to one another via an adjusting device 18. The lower part of the drafting device 101 shown here can be connectable via a top roller carrier (not shown), which carries the top rollers (not shown) of the respective roller pairs, wherein the top rollers form passive rollers in the absence of their own drive.

[0123] FIG. 2B shows a view of a start of the warm-up of an apron bottom roller 24 and/or output bottom roller 26 in one embodiment of the drafting device 101, wherein the sliver 31 is severed in a severing region 25.

[0124] FIG. 2C shows a view of a sliver position after the end of the warm-up of the apron bottom roller 24 and/or output bottom roller 26 in one embodiment of the drafting device 101. The severing region 25 can be located in a region of a compressor that is positioned upstream of the apron bottom roller 24.

[0125] During a step 7 as described with reference to FIG. 1, the spinning station with the cleaning nozzle can move to the cleaning position. Excess fibers that arise during a warm-up can be removed more easily without causing fiber clogging, in particular in a spinneret 40. The cleaning position is in particular variable and can have two different variants as shown in FIGS. 3A and 3B and described below.

[0126] FIG. 3A shows a view of a first cleaning position in one embodiment of the drafting device 101. A sliver 31 is guided between an output top roller 27 and an output bottom roller 26 and transported by the rotation of the rollers. A spinning pressure inside the spinneret 40 can be switched off, and the spinneret 40, which is formed from two housing parts, can be closed, i.e., cannot open. As a result, the fibers of the sliver 31 or its fragments 14 can enter either the upper suction unit 13 or the lower suction unit 15, which are correspondingly arranged in the region of the output roller pair formed by the output bottom roller 26 and output top roller 27 and are assigned to them, and therefore sucked off.

[0127] FIG. 3B shows a view of a second cleaning position in one embodiment of the drafting device 101. The spinning pressure can be switched on and the spinneret 40 can be open or opened by a relative movement in the direction of the double arrows of one of the two housing parts, which carries the spinning cone 42 of the spinneret 40, relative to the other housing part, which carries the fiber inlet 21. In particular, the fibers of the sliver 31 or its fragments 14 are sucked through the fiber inlet 21 and via a fiber suction unit 23 communicating with the spinning chamber in the open position of the spinneret 40, i.e., in a spaced-apart position of the spinning cone 42 from the fiber inlet 21 (not shown). After the step 7 of stopping the output bottom roller drive 36 and the apron bottom roller drive 34 has elapsed, the spinning station in particular resumes its normal spinning position (spinning pressure on, spinneret 40 closed as shown in FIG. 3A). The next process steps then take place as described elsewhere. The second return 8 of the thread follows, and the drafting device 101 or its bottom rollers 20, 22, 24, 26 is/are accelerated using the parameters in step 9 described elsewhere. In particular, the parameters in step 9 are adapted such that they can be used to transport the fibers to the spinneret 40. In particular, significantly longer times are entered for this purpose. The piecing ramp for this case is schematically illustrated in FIG. 4 (not to scale).

[0128] FIG. 4 shows a schematic representation of a piecing ramp 420 of a driven output bottom roller 26 in comparison to a piecing ramp 410 of a driven roller of a thread take-off. The time 415 in milliseconds (ms) is plotted on the X-axis. The speed of the output bottom roller 26 or the driven roller of the thread take-off is plotted on the Y-axis, approximately in units of revolutions per minute. A sliver feed 400 is realized in particular within a time range (negative time range). In particular, the output bottom roller 26 is already activated, which is why a piecing ramp 420 already forms at this time. The thread take-off is still stopped at a zero time (selected as the starting point of the speed increase of the driven output bottom roller 26 in a piecer ramp 420). This makes the following things possible:

[0129] In particular, the first start-up of the apron bottom roller drive 34 and of the output bottom roller drive 36 without the sliver 31 takes place in this first time range. In particular, this prevents the breakaway torque from having an effect in this zone. Furthermore in particular, the piecing takes place when the drafting device 101 has already started up, which can reduce stress in the sliver 31.

[0130] FIG. 5 shows a schematic representation of a piecing ramp 530 with a support point 550. The speeds 505 are plotted against the time 515. This results in piecing ramps 510 for a thread take-off roller drive or for the driven thread take-off roller, a piecing ramp 520 for an output bottom roller drive 36 or for the driven output bottom roller 26, and a piecing ramp 530 with a support point for an apron bottom roller drive 34 or for the driven apron bottom roller 24. A first speed stage 551 is formed in front of a first support point 550. The thread take-off can remain in a dwell time 540. The dwell time 540 of the thread take-off runs in particular in such a way that the thread end is held in the spinning chamber and makes it possible to adjust the preparation of the drafting device 101. This is shown in step 10 in FIG. 1 and described with reference thereto. In particular, the thread take-off ramps up at the end of its dwell time 540 in accordance with the entered acceleration while the drafting device 101 in particular also ramps up. In particular, the thread is pulled out of the spinning chamber and the piecing process is completed, in particular after the ramp-up times have elapsed. The total ramp-up time 560 of the drafting device 101 is indicated, as is the total ramp-up time 570 of the thread take-off.

[0131] FIG. 6 shows a schematic representation of a piecing ramp 630 for an output bottom roller drive or for the driven output bottom roller 26 with an S profile 610, 620 as an example of a process parameter. The speed 605 is plotted over the time 615. In particular, the ramp-ups of the drives (of the bottom rollers 20, 22, 24, 26) take place not exclusively linearly, but with an S-curve, which can be adjustable. This means that extreme accelerations can be avoided. The S profile 610, 620 can be realized both for the thread take-off and for the drafting device 101 or its driven bottom rollers 20, 22, 24, 26.

[0132] FIG. 7 shows acceleration ramps (speed 705 over time 715) of the drafting device 101, wherein only one support point 725 can be formed during the ramp-up in an acceleration ramp 710 of a thread take-off roller drive. An acceleration ramp 720 of an output bottom roller 26 is shown, as is the acceleration ramp 730 of an input bottom roller 20. The corresponding explanations of FIG. 5 also apply here.

[0133] FIG. 8 shows acceleration ramps (speed 705 over time 715) of the drafting device 101, wherein three support points 725, 735, 745 can be formed by way of example during the ramp-up of an acceleration ramp 720 of an output bottom roller 26. The corresponding explanations of FIGS. 5 and 7 also apply here. The three support points 725, 735, 745 mean in particular a definition of a variable speed 705, which can be reached after a variable time 715. This change can, for example, prevent the tendency of the piecers to create a thin point after the binding zone. In particular, this results in a more flexible design of the fiber mass during piecing.

[0134] Can in particular refers to optional features of the invention. Accordingly, there are also developments and/or exemplary embodiments of the invention which additionally or alternatively have the respective feature or the respective features.

[0135] From the combinations of features disclosed in the present case, isolated features can also be taken as needed and used by resolving a structural and/or functional relationship possibly existing between the features in combination with other features for delimiting the subject matter of the claim.

LIST OF REFERENCE SIGNS

[0136] 1 Catching a thread end of a thread [0137] 2 Placement of a thread section of the thread in the take-up [0138] 3 Cutting the thread with scissors [0139] 4 Unraveling the thread end [0140] 5 First return of the thread [0141] 6 Laying a thread loop [0142] 7 Combing out and keeping warm [0143] 8 Second return [0144] 9 Stopping the output bottom roller [0145] 10 Dwell time [0146] 11 Running time of the thread take-off [0147] 12 Carrier [0148] 13 Upper suction unit [0149] 14 Fragments [0150] 15 Lower suction unit [0151] 16 Locking device [0152] 18 Adjusting device [0153] 20 Input bottom roller [0154] 21 Fiber inlet [0155] 22 Center bottom roller [0156] 23 Fiber suction unit [0157] 24 Apron bottom roller [0158] 25 Severing region [0159] 26 Output bottom roller [0160] 27 Output top roller [0161] 28 Apron [0162] 29 Apron bridge [0163] 30 Input bottom roller drive [0164] 31 Sliver [0165] 32 Center bottom roller drive [0166] 34 Apron bottom roller drive [0167] 36 Output bottom roller drive [0168] 40 Spinneret [0169] 42 Spinning cone [0170] 100 Piecing method [0171] 101 Drafting device [0172] 400 Sliver feed [0173] 410 Piecer ramp for a thread take-off drive [0174] 405 Speed [0175] 415 Time [0176] 420 Piecer ramp for an output bottom roller drive [0177] 505 Speed [0178] 510 Piecer ramps for a thread take-off drive [0179] 515 Time [0180] 520 Piecer ramp [0181] 530 Piecer ramp with one support point [0182] 540 Dwell time [0183] 550 Single support point [0184] 551 Speed level [0185] 560 Total ramp-up time of the drafting device [0186] 570 Total ramp-up time of the thread take-off [0187] 605 Speed [0188] 610, 620 S profile [0189] 615 Time [0190] 630 Piecer ramp of an output bottom roller with S profile [0191] 705 Speed [0192] 710 Acceleration ramp of a thread take-off roller drive [0193] 715 Time [0194] 720 Acceleration ramp of an output bottom roller [0195] 730 Acceleration ramp of an input bottom roller [0196] 725, 735, 745 Support points