EP2184387A1 - Method for operating an open ended spinning frame and open ended spinning machine - Google Patents

Abstract

The method involves producing a cross-coil (19) by a coil winder, and temporarily storing yarn quantity by a yarn storage device that is formed during powering of a set of normal workplaces (54) due to different run-up speeds of a spinning device and the coil winder. A yarn tension is measured, and the run-up speed of the coil winder is adjusted depending on the yarn tension. Run-up curves for different diameters of the cross-coil are determined from the adjusted speed, and the diameter-dependent run-up curves are utilized for the respective portion, while powering the workplaces. An independent claim is also included for an open ended spinning machine with a set of workplaces.

Description

The invention relates to a method for operating an open-end spinning machine with a plurality of jobs, wherein a job has a spinning device and a thread withdrawal device and a winding device for producing a cross-wound bobbin and a thread storage device temporarily stores the amount of thread during startup of the job in Result of different acceleration speeds of spinning device and winding device arises. Furthermore, the invention relates to an open-end spinning machine for carrying out the method.

For storing the thread during startup often pneumatic working yarn stores are used in practice. Such thread stores are for example by the DE-AS 2 221 316 through which DE 101 39 075 A1 or by the DE 10 2005 055 717 A1 known.

In the DE-AS 2 221 316 is described an open-end rotor spinning machine whose jobs have an open-end spinning device, a winding device and a thread take-off device. The thread withdrawal device ensures that during regular spinning operation the thread is withdrawn at a constant delivery speed from the open-end spinning device and delivered to the winding device. Following the thread take-off device, a thread-storing nozzle which can be subjected to negative pressure is arranged, which detects the thread excess occurring when a workstation is raised stores temporarily and then delivers successively to the winding device of the relevant job.

Open-end rotor spinning machines, whose jobs are equipped with similarly trained pneumatic thread stores, are also by the DE 101 39 075 A1 or the DE 10 2005 055 717 A1 known. However, the workstations of these known open-end rotor spinning machines each have, in addition to the pneumatically operating thread store, also a mechanical thread store. The movably mounted Fadenleitorgan this mechanical thread storage is defined by means of an electric motor actuator so displaced that during the regular winding process occurring due to the Fadenchangierung yarn length variations are compensated.

In the above-described, proven per se pneumatic thread stores, however, it has turned out to be somewhat problematic to exactly meet the time at which the memory is properly emptied, that is, to determine the period in which the cheese after the start of the Workstation must be driven at a winding speed that is slightly above the yarn delivery speed of the open-end spinning device, especially since this period depends on numerous parameters that change with each new batch.

Since a cheese driven for too long with increased winding speed usually leads to a thread break, while a cross-wound bobbin, in which the winding drive was taken back too early on yarn delivery speed, without the necessary thread tension, it is further basically known to equip such pneumatic yarn storage with a sensor that monitors the memory contents.

Such, for example in the DE 10 2004 057 825 A1 In connection with a cross-winding machine described means for monitoring the filling state of a pneumatic yarn store are usually designed as optical or capacitive sensor devices and relatively expensive. This means that use of such sensor devices in open-end rotor spinning machines, which have 300 or more jobs, is less economical and therefore hardly meaningful.

Based on the aforementioned prior art, the present invention seeks to enable a safe start-up of the work and to adjust the speed of the winding device during startup in a simple and cost-effective manner.

The object is achieved by the characterizing features of the method claim 1 and the device claim 2. Advantageous developments of the invention are the subject of the dependent claims.

To solve the problem, the thread tension at startup is measured at least at one workstation (54) for different diameters of the cross-wound bobbin at a new batch and the run-up speed of the winding device is set as a function of the measured thread tension. In this case, the thread tension is a measure of the filling state of the thread storage device. According to the invention, from the set speeds in each case a run-up curve for the different diameters of the cross-wound bobbin determined and then these diameter-dependent ramp-up curves for each lot at startup of jobs used. By determining the run-up curves from measurements of the thread tension, the different parameters of a respective batch are automatically taken into account. Since such a measurement is required only during a batch change, the application of the method according to the invention is particularly simple.

In addition to the batch parameters, the diameter of the respective cross-wound bobbin plays a role during run-up. As a result, the periods until emptying of the thread storage and thus the time at which the winding speed must be lowered again, change. Therefore, run-up curves are determined for different cheese diameter. That is, it is measured for various cheese diameter, the yarn tension and set the winding speed. After diameter-dependent run-up curves have been determined in this way, either a current run-up curve closest to the current diameter of the cross-wound bobbin can be selected, or a run-up curve for the respective cross-bobbin diameter can be interpolated from the measured run-up curves.

To carry out the method, an open-end spinning machine with a plurality of jobs is also proposed, wherein a job has a spinning device, a winding device for producing a cross-wound bobbin and a thread storage device in which temporarily the amount of thread can be stored, which during startup of Job arises as a result of different ramp speeds of spinning and winding device. According to the invention is a job equipped as a pilot workstation with a yarn tension sensor for measuring the yarn tension and control means are adapted to adjust depending on the measured yarn tension, the acceleration speed of the winding device and to determine from the set speeds a diameter-dependent run-up curve for a new batch. Further, control means are adapted to use the run-up curve during startup of the workstations not designed as pilot workstations.

In a preferred embodiment of the open-end spinning machine according to the invention, the yarn tensile force sensor is firmly mounted on the pilot workstation. The pilot workstation then preferably also has the corresponding control means for determining the run-up curves. It is then only the pilot workstation equipped accordingly. The remaining jobs can be made simpler and in particular need no yarn tension sensor.

In a further preferred embodiment of the open-end spinning machine according to the invention, at least one workstation is designed to receive a yarn tensile force sensor and to function as a pilot workstation. In this case, the yarn tensile force sensor of the pilot workstation is interchangeable and can also be mounted on other workstations designed for this purpose. This allows a job to be quickly converted to a pilot job. This is an advantage if different parts are produced simultaneously on a spinning machine. It is also possible to use the yarn tension force sensor for various spinning machines and thus obtain a further cost advantage. The yarn tension force sensor may include its own control means for determining the run-up curve. Advantageously, however, the yarn tension force sensor is sent to the control unit of connected to the respective job. The workstation controls are usually microprocessor-controlled today, so that the control and evaluation functions for the thread tension signal can be implemented as software and thus no additional hardware is required.

The invention will be explained in more detail with reference to an embodiment shown in the drawings.

Fig. 1

eine erfindungsgemäße Offenend-Spinnmaschine mit einer Pilotarbeitsstelle zur Bestimmung einer Hochlaufkurve;

Fig. 2

eine perspektivische Darstellung der Pilotarbeitsstelle mit einem Fadenzugkraftsensor;

Fig. 3

eine Seitenansicht der Pilotarbeitsstelle.

Show it:

Fig. 1

an open-end spinning machine according to the invention with a pilot workstation for determining a run-up curve;

Fig. 2

a perspective view of the pilot job with a yarn tension force sensor;

Fig. 3

a side view of the pilot job.

Fig. 1 schematically shows a front view of an open-end rotor spinning machine 1 with so-called end frames 52, 53, which, as known and therefore not shown in detail, through through supply and disposal channels, such as a vacuum channel for supplying the spinning devices with spinning vacuum, an electronic channel for a bus system and / or a yarn monitoring device and a cable channel for supplying the work stations 54 with electrical energy, are connected. At this supply and disposal channels, which are quasi the "backbone" of the textile machine, the Garnbildungs- or cross wound winding devices of the rotor spinning machine 1 can be fixed, which form a variety of normal jobs 54 and a pilot workstation 10. At workstations 54, a masterfibre tape is placed in Spinnkannen 16 is stored, spun into a yarn which is wound on cheeses 19. In the end frames 52 and 53, for example, a (not shown) textile machine's own vacuum supply device, an electrical power supply and a central control unit 55 of the rotor spinning machine 1 are arranged. The central control unit 55 is in turn connected to the workstation computers 6 of the individual normal workstations 54 and the pilot workstation 10, preferably via a bus system 7.

In the Figures 2 and 3 In each case a pilot workstation 10 is shown. On the pilot workstations 10, as well as on the workstations 54, by means of an open-end spinning device 12, an original fiber web is spun into a yarn 17, which is then wound on a winding device 18 to form a cheese 19. Such a winding device 18 has, inter alia, also a creel 8 for rotatably supporting a package.

The pilot workstation 10 as well as each of the workstations 54 of the open end rotor spinning machine has a number of other, different thread handling or thread handling devices that allow for proper operation of the workstations. Each workstation has, for example, a yarn draw-off device 20, a suction nozzle 21, a thread-changing device 22 with a traversing yarn guide 51 which can be driven by a single motor, and a reel drive device 23 whose reel drive roller 14 is driven, for example, by an electric motor 27. The individual drive 24 for the thread withdrawal device 20, the single drive 25 for the suction nozzle 21, the single drive 26 for the traversing yarn guide 51 and the single drive 27 for the coil drive roller 14 are via control lines 28 - 31 to a Workstation computer 6 connected, which in turn, preferably via a bus system 7, is connected to the central control unit 55 of the textile machine. The yarn 17 produced in the open-end spinning device 12 is withdrawn from the open-end spinning device 12 by the yarn draw-off device 20 at a constant yarn delivery speed.

Furthermore, a thread monitor 3, a pneumatic thread store 4, a mechanical thread store 2 and a waxing device 5 are arranged in the area of the thread running path.

The pneumatic yarn store 4 has a suction nozzle which can be subjected to negative pressure, which is arranged directly behind the regular yarn running path and, if required, sucks in the running yarn 17 in the form of a loop and temporarily stores a certain yarn length. Such pneumatic yarn storage 4 are known per se and for example in the DE 10 2005 005 717 A1 described in detail.

In the direction of yarn travel F behind the pneumatic yarn store 4, the mechanical yarn store 2 is arranged both at the pilot workstation 10 and at every other workstation 54. This mechanical thread store 2 has two stationary thread guide rollers 38, 39 and a movably mounted thread deflection roller 36. The Fadenumlenkrolle 36 is disposed on a spring member 32, preferably a leaf spring element, which in turn is fixed to a lever 35. To the adjusting lever 35, which is limited rotatably mounted, a drive, preferably a thrust piston 37, articulated, which allows a defined displacement of the control lever 35 and thus the Fadenumlenkrolle 36.

Unlike at the other workstations 54, the spring component 32 is equipped at the pilot workstation with a sensor element 33 which detects mechanical deformations of the leaf spring component 32. The sensor element 33 designed, for example, as a film strain gauge is connected via a signal line 34 to the workstation's own control device 6. The workstation's own control device 6 of the pilot workstation 10 evaluates the thread tension during the run-up of the job and adjusts the run-up speed accordingly. From this data, the run-up curves for the other jobs can then be determined.

In the illustrated embodiment, the leaf spring member 32 is connected by means of a screw 56 to the adjusting lever 35 and the control line 34 of the sensor element 33 is connected via a plug connection, not shown, with the control unit 6. In this way, the leaf spring member 32 with the sensor element 33 is easily replaceable and can also be mounted at other work sites 54. The leaf spring component 32 with the sensor element 33 then forms an exchangeable yarn tensile force sensor. This means that every job can be converted into a pilot job. The software for determining the run-up curve can be provided in each workstation control or is loaded if necessary.

As an alternative to the variant with the exchangeable yarn tensile force sensor, a permanently installed sensor can also be used.

During the normal working process, the thread 17 produced in the open-end spinning device 12 is replaced by the Thread withdrawal device 20 withdrawn at a constant yarn delivery speed from the open-end spinning device 12 and wound on the winding device 18 to form a cheese 19. The cross-wound bobbin 19 rotatably mounted between the arms of a creel 8 rests with its surface on the drive motor drum 14 which is driven by a single motor and is driven by the latter via frictional engagement in the winding-up direction. The running onto the cheese 19 thread 17 is simultaneously laid by means of Fadenchangiereinrichtung 22 so that it runs in intersecting layers on the lateral surface of the cheese 19, which occur during the regular winding operation yarn length variations are compensated by the mechanical yarn storage 2.

If it comes to one of the jobs 54 of the open-end rotor spinning machine to a fault, such as a thread break, which is preferably detected by the thread monitor 3, the workstation computer 6 ensures that both the open-end spinning device 12 of the relevant job 10 and the associated winding device 18 are stopped.

The workstation computer 6 also ensures that the workstation's own suction nozzle 21 is pivoted into a thread receiving position in the immediate vicinity of the lateral surface of the cheese 19 and subjected to negative pressure. Subsequently, the bobbin drive roller 14 is slowly rotated in the unwinding, so that the accumulated after the yarn breakage on the lateral surface of the cheese 19 can be absorbed by the suction nozzle 21.

During the subsequent downward pivoting of the suction nozzle 21 in the region of the open-end spinning device 12, the thread is placed behind the thread deflection roller 36 of the opened mechanical thread store 2, passed in front of the mouth of the pneumatic thread store 4 and positioned between the thread take-off rollers of the thread take-off device 20. Subsequently, the thread take-off device 20 is closed, brought the mechanical yarn storage 2 in the operating position, in which the Fadenumlenkrolle 36 is again pivoted between the yarn guide rollers 38 and 39, and the pneumatic yarn storage 4 subjected to negative pressure. The suction nozzle 21 transfers the received thread end to a piecing element 9 arranged in the region of the open-end spinning device 12, which prepares the thread end for re-piecing. The drive 24 of the thread withdrawal device 20 is then controlled by the workstation computer 6 so that a defined thread return of the prepared thread end takes place in the direction of the open-end spinning device 12.
Since the piecing element 9 is under the influence of the negative pressure prevailing inside the open-end spinning device 12, the prepared thread end is sucked into the open-end spinning device 12 and applied to a fiber ring revolving within the open-end spinning device 12, which is thereby broken.

The newly emerging thread 17 is withdrawn via the current again in the withdrawal direction thread withdrawal device 20 and wound on the winding device 18 to a cross-wound bobbin 19.

Since the cross-wound bobbin 18 can not be accelerated to operating speed with the same dynamics during the piecing process as the functional elements of the open-end spinning device 12, the yarn delivery speed of the open-end spinning device 12 is initially slightly above the winding speed of the cheese 19, with the result that sets a thread excess. This resulting excess yarn is temporarily stored by the pneumatic yarn store 4 in the form of a thread loop.

To empty the pneumatic thread store 4, that is, to re-dissolve the cached thread loop, the cross-wound bobbin 18 is slightly accelerated beyond its regular operating speed, that is, the cross-wound bobbin 18 is rotated at a winding speed which is slightly above the yarn delivery speed of the open-end spinning device 12 , The increased winding speed is maintained until the pneumatic yarn store 4 is completely empty, then the cross-wound bobbin is again rotated at a winding speed corresponding to the yarn delivery speed of the open-end spinning device.

The exact time at which it must be switched back to regular winding speed, is set via a ramp-up curve. The run-up curve is determined in a new lot by tests at the pilot workstation 10. At the pilot workstation 10, the time at which it is necessary to switch back to the regular winding speed can be detected by means of the sensor element 33 on the mechanical yarn store 2. That is, as soon as the thread loop has dissolved in the pneumatic yarn store 4, it comes to an increase in the thread tension due to the excessive winding speed of the cheese 18, which is transmitted via the Fadenumlenkrolle 36 to the spring member 32.

The occurring mechanical deformation of the spring component 32 is detected directly by means of the arranged on the spring member 32 sensor element 33 and forwarded via the signal line 34 to the control device 6 of the pilot workstation 10. The control device 6 then processes this signal to the effect that the motor of the bobbin drive roller 14 is immediately switched back to regular winding speed. The winding speeds set in this way are stored in a run-up curve and made available to the other workstations 54 via the bus system 7. The tests at the pilot workstation 10 are repeated for different diameters of the cross-wound bobbin, so that a series of run-up curves results.

By correctly switching the winding drive on the one hand reliable yarn breaks can be avoided, resulting from too long operation with excessive winding speed, on the other hand can be avoided that cheeses are wrapped without sufficient thread tension, because already switched back to regular winding speed before the thread loop in the pneumatic Fadenspeicher 4 was completely dissolved.

Claims (4)

Method for operating an open-end spinning machine (1) having a plurality of workstations (54), wherein a workstation (54) via a spinning device (12) and via a thread take-off device (20) and a winding device (18) for producing a cross-wound bobbin (19 ) and a thread storage device (4) temporarily stores the amount of thread that arises during startup of the workstation (54) as a result of different startup speeds of the spinning device (12) and winding device (18), characterized in that at least one first at a new batch Workstation (54) for different diameters of the cross-wound bobbin (19) the thread tension is measured at startup, wherein the thread tension is a measure of the filling state of the thread storage device (4), that in response to the thread tension the startup speed of the winding device (18) is adjusted in that from the set speeds in each case a H ochlaufkurve for the different diameters of the cheese (19) is determined and that then these diameter-dependent run-up curves for each lot when starting up the jobs (54) are used. Open-end spinning machine for carrying out the method according to one of claim 1 having a plurality of jobs (54), each workstation (54) via a spinning device (12) via a winding device (18) for producing a cross-wound bobbin (19) and via a Thread storage device (4) has, in the temporarily the amount of thread can be stored, during startup of the respective workstation (54) as a result of different acceleration speeds of spinning device (12) and Winding device (18) is produced, characterized in that at least one of the workstations (54) is equipped as a pilot workstation (10) with a yarn tension force sensor (33) for measuring the yarn tension and control means (6) are designed, depending on the measured yarn tension Start-up speed of the winding device (18) to set and determine from the set speeds diameter-dependent run-up curves for a new lot and control means (6) not designed as pilot jobs (10) jobs (54) are designed to use the determined diameter-dependent run-up curves during startup. Open-end spinning machine according to claim 4, characterized in that the yarn tension force sensor (33) is fixedly mounted on the pilot workstation (10). Open-end spinning machine according to claim 4, characterized in that at least one workstation (54) is adapted to receive a yarn tension force sensor (33) and to act as a pilot workstation (10).

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