EP0090911A2 - Method and apparatus to optimize a work occurrence at each working station of a textile machine - Google Patents

Abstract

On textile machines on which bobbins with a desired yarn length are wound, the changing of these bobbins by means of a mobile bobbin changing device should be carried out optimally in time so that as many bobbin positions as possible can be operated with the bobbin changing device. For this purpose, a computer (12; 121; 122) continuously signals the yarn length of bobbins to be wound (1 to 8) by means of yarn length measuring units (111 to 118) and the position of a bobbin changer (10; 101) by means of positioning units (131 to 138). If certain bobbins reach a remaining yarn length before the target yarn length is reached, the winding times for the remaining yarn lengths of these bobbins are compared with the respective travel times of a bobbin changer (10; 101) to these bobbins by the computer and, for example, three of these bobbins are recorded in an optimization process. For these three recorded spools, the computer determines a spool change order in which waiting times until the individual spools are changed are zero or at least as short as possible.

Description

The invention relates to a method and a device for the temporal optimization of a work schedule at individual workplaces of textile machines, according to the preamble of claims 1 and 15.

It is known that for bobbins that are used as a template for the so-called warping process, a uniformly wound yarn length is desired in order to avoid losses due to remaining yarn lengths that are no longer usable on the feed bobbins that are not yet completely empty.

Uniformly wound yarn lengths can be achieved in an open-end spinning process, also known as a rotor spinning process, by measuring the yarn lengths during the winding process by means of a length measuring unit and by interrupting the spinning process per spinning station for the bobbin changing process when a predetermined target yarn length is reached.

The changing process can be carried out either manually or by means of stationary thread attaching and bobbin changing devices which are provided for each spinning station or by means of corresponding devices which move along the spinning stations.

The manual variant mentioned is not only labor-intensive, but also requires the operator to be particularly skilled in threading so that the threading points are neither too thin nor too thick. At high rotor speeds, e.g. over 60,000 rpm. manual threading is practically impossible anyway.

On the other hand, thread attaching and bobbin changing devices, which are provided for each spinning station, are an economically expensive solution.

The economy is improved with the mentioned moving devices. Such devices are automatically moved to this spinning station for the changing process on the basis of an interruption reported to a controller at an individual spinning station.

The disadvantage of the last-mentioned method step, however, is the still relatively long waiting times of the individual spinning stations until the change is completed, in particular when it is necessary to change almost several bobbins which may be at a distance from one another.

To at least partially remedy this disadvantage in German Offenlegungsschrift No. 30 30 504 proposed to control a bobbin changing device by means of a length measuring device in combination with a computing unit to the spinning station at which the bobbin has at least approximately reached the desired length. The length measuring device determines the yarn length of a number of spinning positions assigned to it and reports these lengths continuously to the computing unit in which these length values are stored and each compared with the target value.

If a predetermined maximum difference in length from the setpoint is reached for a bobbin, then the computing unit commands the bobbin changing device as a precaution to this bobbin, so that the bobbin changing process is triggered when the yarn length corresponding to the setpoint is reached. The removal of the full bobbin is followed by the insertion of an empty tube and the attachment of the yarn end separated from the full bobbin. The removal of the full bobbin and the insertion of the empty tube, as well as the attachment of the yarn end to the empty tube, is also called "doffing" and the device which carries out this "doffing" is called "doffer" for short.

The maximum length difference mentioned corresponds to the long travel time required for the doffer, including the time for the doffing itself.

The disadvantage of this method is the long waiting time until the bobbin changing process, with only short travel times required. This disadvantage has the consequence that the frequency of changing bobbins is very limited.

The object of the invention is therefore to remedy this disadvantage.

The invention solves the problem in terms of method and device in the manner characterized in claims 1 and 15.

The advantage achieved by the invention in comparison with the aforementioned prior art can essentially be seen in the fact that, as a percentage of an equal number of spinning positions, more bobbin changes can take place without interrupting the spinning process than is possible with the method of DOS 30 30 504.

In the following, the invention will be explained in more detail with the aid of examples that merely illustrate ways of implementation.

• Fig. 1 ein erfindungsgemässes Verfahren rein schematisch dargestellt
• Fig. 2 je eine schematische Darstellung des zeit-und 6 lichen Ablaufes
• Fig. 3-5 je eine schematische Darstellung des zeit-und 7-8 lichen Ablaufes der einzelnen Erfindungsbeispiele.

It shows:

• Fig. 1 shows a method according to the invention purely schematically
• Fig. 2 each a schematic representation of the time and 6 Liche process
• 3-5 each show a schematic representation of the time and 7-8 process of the individual examples of the invention.

A changing device 10 (FIG. 1) travels along a textile machine (not shown) for producing yarn packages with predetermined desired yarn lengths (shown with a dash-dotted line) in order to form one the time described later to change the bobbins marked with the numbers 1 to 8 and belonging to the winding process of the textile machine after reaching the desired yarn length against empty tubes (not shown).

A yarn length sensing element 111 to 118, which is known per se from DOS 3030504 and is assigned to each bobbin, continuously measures the length of the yarn to be wound and emits a signal corresponding to this length to a computing unit 12. Furthermore, the computing unit is assigned a positioning element 131 to 138, e.g. One limit switch each, signals the position of the changing device.

The times required for the winding phases and for moving the changing device, waiting and changing the bobbin are shown graphically in FIGS. 2 and 6. Here, t is a time which is required to reach the predetermined desired yarn length, t _{R is} a time which is required to wind up a predetermined remaining yarn length and t is a waiting time for a bobbin which has stopped after reaching the desired yarn length until the start of change.

A time required for the travel of the changing device is denoted by t _S , the time required for the waiting of the changing device until the bobbin change and t _D the time required for the bobbin change.

In operation, the arithmetic unit 12 is continuously scanned by the yarn scanning elements 111 to 118 while the individual bobbins 1 to 8 are being generated Yarn lengths signaled.

If, for example, three bobbins are considered in terms of control for the temporal optimization of a bobbin change, the computing unit 12 compares the bobbin time of all the bobbins that have reached the time range of the remaining yarn length t _R with the respective travel time until the desired yarn length is reached Change device to these coils and selects the combination for three coils that results in the shortest possible waiting time t _u for the three selected coils.

• Der Rechner 12 hat wie in Figur 3 graphisch dargestellt die Restgarnlängen t_R4, t_R5 und t_R7 der Spulen 4,5 und 7 für die Optimierung O₁ erfasst und entsprechend der notwendigen Weglängen eine Wechselreihenfolge A⁰ festgelegt, in der die Spulen 4,7 und 5 in dieser Reihenfolge gewechselt werden müssen.

Example (Fig. 3):

• As shown graphically in FIG. 3, the computer 12 recorded the remaining yarn lengths t _R4 , t _R5 and t _R7 of the bobbins 4, 5 and 7 for the optimization O ₁ and determined an alternating sequence A ^{0 in} accordance with the necessary path lengths, in which the bobbins 4, 7 and 5 must be changed in this order.

To explain this example, it should also be mentioned that the travel time of the changer 10 from the coil 1 to the coil 4 with t _s , from the coil 4 to the coil 7 with t _s and analogously between the coils 7 and 5 with t _{S7 -5} is called. In addition, the remaining times relating to a specific coil are provided with an index corresponding to the coil number.

• Für Spule 4:
  
• für Spule 7:
  
• für Spule 5:
  
  

Ideally, the time t _{total of} the bobbin changer used to dope the three named bobbins, in which the times t _W and t _U = 0, looks mathematically like follows from:

• For coil 4:
  
• for coil 7:
  
• for coil 5:
  
  

In the normal case (FIG. 4), t _W4 , t _W7 and t _{U5 would} not be zero, but the time t _{U5 would} be as short as possible. The times t ' _R4 , t' _R7 and t ' _R5 accordingly differ from the times ⁴ t _R , t _R7 and t _R5 (all in FIG. 3) and are determined by the optimization O ₂ .

However, after the end of a bobbin change, the computer determines that priority has been given to another change sequence in the meantime If, for example, in order not to change the coil 5 but the more distant coil 8 after changing the coil 7, the computer changes the sequence. With a further optimization 0 ₃ (FIG. 5), the computer has determined that the remaining yarn length t _R8 comes to an end shortly after the remaining yarn length t _R that a new change sequence ⁵ A ^I , in which the bobbin 8 after the bobbin 7 and before the coil 5, the total waiting time t _U results, namely the time t _U5 . The times for this change order are shown in FIG. 5 with solid lines.

In the same figure, dashed lines show the chronological course of an alternating order A, from which it can be seen that in such an order the sum of the times t ' _u and t _{U8 is} greater than the time t _U5 , the order AI.

As a variant, the aforementioned optimization method can also be used for a rotor spinning machine, on which the bobbins 1 to 8 are additionally produced with a predetermined excess length that goes beyond the desired yarn length.

The time required for this excess length is denoted by t _Ue (FIG. 6).

The waiting time t _U following this excess length t _{Ue is} the mean time after the bobbin has stopped, ie after the time t _{Ue has} elapsed until the bobbin is changed and the thread is reattached, be it manually or mechanically.

In the operation of this variant, a computer 121 (FIG. 1) of all the bobbins which have reached the time range of the remaining yarn length t _R compares the remaining take-up time up to and with the time t _Ue for reaching the maximum excess length with the respective travel time of the changing device to these coils and selects the combination for three coils that results in the shortest possible time t _Ue for the three selected coils. An example of such a variant is shown in FIG. 7, in which a bobbin changer 101 changes the bobbins 4, 7 and 5 in succession from the position shown in FIG. 1 in accordance with the change order A ^III .

Optimization 0 ₄ has previously detected the remaining yarn lengths t " _R4 , t" _R7 and t " _{R in} such a way that the bobbins 4 and 7 are produced without and the bobbin 5 with excess length.

In the example shown in FIG. 8, after changing the coil 4, a new change priority is selected by the computer 121 in order to first change the coil 8 and then the coil 5 according to a change order A ^IV after changing the coil 7. This sequence of changes is determined beforehand by optimization 0 ₅ .

It can be seen from FIG. 8 that the coils 7 and 8 are changed without excessive length, whereas the coil 5 is stopped after the excess length has been reached until the coil is changed, ie during a waiting time t by a length measuring unit belonging to the memory. The time t _U is due to a subsequent manual or mechanical change of the bobbins of the corresponding spinner le limited.

If the bobbins are changed manually, the computer 121 also triggers a signal for this corresponding winding unit after the time t _{Ue has} expired and temporarily switches this winding unit off from the optimization program. The resumption into the optimization program takes place, for example, through manual signaling (not shown) by the operator after changing the bobbin and attaching the thread to the corresponding spinning position. Attaching the thread can be understood as either attaching to the new bobbin with the spinning process not interrupted at this spinning position or re-spinning with an interrupted spinning process.

Another variant of the use of the optimization method is that the time of cleaning the rotors of the individual spinning stations after the spinning station is stopped is optimized by means of a yarn length measuring unit belonging to a computer 122.

The optimization method works according to the variant shown and described with FIGS. 2, 4 and 5.

The recorded times t _{R of} the remaining yarn lengths correspond to the remaining yarn lengths before the time of cleaning and the waiting times t are waiting times after stopping the spinning process per spinning station until the time of cleaning. After completing the optimization process for cleaning the rotors, the optimization process for changing the bobbin described above occurs spotting function, if necessary at the same time as the bobbin change, also for repeated rotor cleaning when changing and for re-spinning.

A second variant of the use of the optimization method for cleaning the rotors of the individual spinning positions consists in cleaning within a time range subsequent to a predetermined target time for cleaning, e.g. after half the target yarn length is reached. The optimization process selects e.g. three spinning positions, the winding times of which are within a time t of a remaining yarn length before reaching the stated point in time.

This optimization method works essentially according to the variant shown and described with FIGS. 6 and 7. The end of the time t _R corresponds to the target time for cleaning the rotor and the time t _Ue shown in FIG. 7 corresponds to the time range within which the rotor cleaning must take place. After the time t _Ue , the spinning station is stopped for the time t. The rotor is cleaned before re-spinning.

As already mentioned for the first cleaning variant, once this optimization process has been completed, the optimization process for the bobbin change, or possibly also simultaneously with the bobbin change, for the repeated rotor cleaning when changing and for re-spinning, also comes into operation.

The distances shown in FIGS. 2 to 8 and corresponding to the different times are not to scale.

For example, the changer 10; 101 a vehicle Speed that allows you to travel along 200 spinning positions in 2.5 minutes and takes 20 to 30 seconds for the bobbin changing, cleaning and re-spinning process.

On the other hand, the claimed method is not only limited to the application for changing bobbins on rotor spinning machines. It can basically be used for all textile machines in which twine bobbins are produced with predetermined nominal yarn lengths and in which the bobbins are changed after reaching this nominal yarn length by a device controlled at the work station.

The invention thus relates to a textile machine with a majority of work stations, a mobile maintenance device, a roadway for the device and a control device. The machine is provided with a data transmission system in order to convey operating status data from the workstations to the control device, position data from the maintenance device to the control device and control data from the control device to the maintenance device. The operating status data represent the operating status of the individual work stations, the position data the position of the maintenance device relative to the work stations. The control data control the movements of the maintenance device along the road. The control device is arranged such that the control data are produced in accordance with the operating state and position data obtained.

The invention further relates to a control method for a Textile machine with a majority of jobs, a mobile maintenance device, a roadway for the device and a control device. The operating states of the various work stations and the position of the maintenance device relative to the work stations can be determined and communicated to the control device as data. The movements of the maintenance device along the road can be controlled by the control device in accordance with the determined operating states and the position.

The textile machine could e.g. an OE spinning machine, a ring spinning machine or a winding machine. The determined operating states could be run times, and / or normal operation / malfunction and / or bobbin fullness (wound yarn lengths. The control device can be arranged in such a way that the movements of the maintenance device are optimized according to a program. The optimization criteria of the program can be the minimum total time of the workflow represent the maintenance device or at least take it into account, whereby under "workflow" preprogrammed maintenance work must be included in a majority of workplaces.

Claims (15)

1.Procedure for the temporal optimization of a work event at individual workstations of textile machines, at which bobbins with predetermined nominal yarn lengths are generated, in which the current yarn length of each bobbin is calculated and registered by calculation and when determining a predetermined remaining yarn length of a bobbin until the execution of the Work event, a device that executes the work event and can be moved to the place of work is controlled to this place of work with such a time advantage that the travel time of the device is shorter than the wind-up time of the remaining yarn length, even if the longest distance is traveled, characterized in that the winding duration of the remaining yarn length a certain number of coils with each travel time of the device from the current location to the work stations of the specific number of coils, taking into account the time for that to be carried out by the device at each of these work stations Work event, mathematically optimized in such a way that such a favorable sequence of work events is determined that a possible loss of production or quality of the yarn per spinning station is the smallest. 2. The method according to claim 1, characterized in that the work event is a bobbin change at a spinning station of a rotor spinning machine, the spinning stations producing bobbins with a predetermined excess length resulting in the loss beyond the predetermined target yarn length, and that the most favorable order of the work events corresponds to a bobbin change order in which the sum of all excess lengths is the smallest. 3. The method according to claim 1, characterized in that the work event is a bobbin change and re-spinning of the spinning process interrupted after reaching the desired yarn length at a spinning station of a rotor spinning machine, and that the most favorable order of the work events corresponds to a bobbin change order, in which the sum of all the interruptions resulting from the loss, given from the time of the spinning interruption to the Ned- * spinning, is smallest. 4. The method according to claim 1, characterized in that the work event is cleaning a rotor of a spinning station of a rotor spinning machine, the spinning process was interrupted after reaching a yarn length that is shorter than the desired yarn length, and that the most favorable order of the work events one The cleaning sequence corresponds to that in which the sum of all interruptions resulting in the loss, from the point in time of the interruption in spinning to the re-spinning, is the smallest. 5. The method according to claim 1, characterized in that the work event is a cleaning of a rotor of a spinning station of a rotor spinning machine at a predetermined point in time before reaching the target yarn length, the cleaning process being the spinning process shut down and after cleaning for the continuation of the spinning process until the desired yarn length is reached again, and that the most favorable sequence of the work event is the cleaning within a time-related tolerance of the specified time which may influence the yarn quality until the work process is carried out. 6. The method according to claim 4, characterized in that the spinning station is stopped after reaching half the target yarn length. 7. The method according to claim 5, characterized in that the predetermined time for carrying out the work event is half the desired yarn length. 8. The method according to claim 5, characterized in that the tolerance plus / minus one tenth of the target yarn length. 9. The method according to claim 2, characterized in that the spinning process is interrupted after winding the excess length. 10. The method according to claim 1, characterized in that the predetermined target yarn length is not fallen below. 11. The method according to claim 1, characterized in that the time lead is chosen such that the winding time of the remaining yarn length one to three times the travel time between the most distant spinning places corresponds. 12. The method according to claim 1, characterized in that the time lead is selected such that the winding time of the remaining yarn length corresponds twice to the travel time between the most distant bobbins. 13. The method according to claim 1, characterized in that at 150 to 200 spinning positions per bobbin changing device, two to five bobbins are included in the optimization. 14. The method according to claim 1, characterized in that at 180 spinning positions per bobbin changing device, four bobbins are included in the optimization. 15. The device for carrying out the method according to claim 1, characterized in that the textile machine is provided with a length measuring unit, which for each bobbin emits a signal corresponding to the length of the yarn already wound to a computing unit, and that the computing unit for determining said time advantage and for controlling the bobbin changing device, characterized in that additional means are provided for emitting a signal for identifying the position of the bobbin changing device, and in that the computing unit is designed such that on the one hand two to five bobbins, the yarn lengths of which reach the remaining yarn length have, be determined and on the other hand the most favorable order of the work events is determined.

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