DE10129201A1 - For a self-setting operation at a yarn processing machine, threshold values are established for a yarn thickness where a yarn break probability can be set, with measurements for variations to alter them for a second probability - Google Patents

Abstract

To give a self-setting operation to a yarn processing machine, e.g. a spinning machine or a bobbin winder or yarn treatment machine and the like, variable outer threshold values (d1,d2) are set for a yarn thickness (d(t)) to give no more than an initial probability level of yarn fractures (e) in a given longer time span. Yarn measurements are taken to vary the outer thresholds to give a second probability value of the breaches (r) of the first narrower thresholds (d3,d4), in a given time unit, to act on the outer threshold values, so that an actual yarn break will occur only on a breach of one of the outer thresholds.

Description

The invention is concerned with the technical field of EP 415 222 B1 (Zellweger Luwa) is described, namely a method for setting limit values that a Separation process in the textile thread (yarn) cause to make the yarn new to spin on or rewind and previously potential errors or remove impurities. With the font mentioned two limit values GO, GU are exceeded, the one cut trigger. Depending on the frequency of cuts, the limits GO, GU changed.

In the technical area mentioned, it is the task of Invention to independently optimize the yarn handling and maximum productivity with the best possible winding or Achieve manufacturing quality in the long term, with inclusion the actual conditions in the machine.

This problem is solved when using a measured thread thickness first limit values that are not compared to a Thread separation (thread cutting), but within second boundaries are actually to the mentioned Perform a thread cut. Exceeding the inner (or: narrower) limit values per given time unit leads to a Change in the actual thread cuts second (or: outer) limit values.

Specifically, the external limits (those that are used for Thread cut) in the aforementioned change to those Limit values can be set that were previously only used as comparative values were of importance with regard to their exceeding. you will be then to the outer limits, to real yarn cuts to lead. The internal limits left an acceptable frequency expect from thread cuts, this expectation is after the Change of outer borders to reality. So far only detected (virtual) yarn cuts, e.g. B. by pulse counting (Claim 5), then become real (actual) thread cuts, the frequency of which was previously tested without statistical methods  use. So far, "virtual" yarn defects have only been closed Quality documentation purposes have been used, cf. CH 680 803 A5 (Zellweger Luwa), column 4 lines 25 to 30, and EP-B 439 768 (Zellweger Luwa), column 3, lines 25 to 37 and Column 4, lines 25 to 40.

New limit values for yarn handling (winding or producing) can be operationally checked with the invention (claim 12), without loss of yarn. The new limits are internal or narrower (initially virtual) limit values, which at running yarn with larger limit values than yarn cut or Real error limit are only of importance to the extent that registered and counted as their exceeding (per impulse) is going to frequency - an expected, currently probable frequency - to determine thread breaks that then occur when the first for review provided internal limits to the actual external Limit values (the limit values generating the thread break).

The device (claim 17) can independently the tolerance band adjust the permissible fluctuation d (t) of the thread thickness, depending from an expected frequency of errors in one to Check set internal or narrower tolerance band and depending on the ability to work - i.e. availability - of a debugging machine.

With the described method and the device - or their Preparation in the sense of use (claim 19) - can be achieved that one for the respective operating case and the respective operating situation maximum possible productivity is achieved because the limit values are exactly such Define the tolerance band that the hiking machine does not yet have overwhelmed, just busy and thus the best possible Yarn quality with the lowest possible yarn error deviation reached.

The time spans within which an initially try with lower tolerance range actually  executed, do not follow short-term decisions, but are longer-term time intervals (claim 2, Claim 3). It follows that the narrower limits can be adjusted much more often (claim 6) than the real limit values of the actually leading to cuts Tolerance band in production.

Initially on a trial basis with inner, narrower limits provided tolerance (claim 9) can with regard to different Error channels or types of errors can be specified. One each these internal limits can then be selected for the actual limit values that cause thread separation. It can also be a compilation of all available inner Limits are taken for the respective types of errors that to a compound tolerance band that initially tentatively, but still during production is applied.

Is the utilization of the hiking machine high (claim 7), is it will not be available to troubleshoot yarn defects to maintain further yarn processing, the tolerance band, the leads to yarn cuts or yarn breaks, increases and can later by lowering it over initially provided on a trial basis reduced internal limit values can be reduced. Is the The walking machine is underutilized, is its ability to work so high, higher quality yarn can be produced by the Limits of the tolerance band that lead to actual thread breaks lead, be reduced (claim 8).

The determination of the just for the respective operating case Tolerable tolerance band (claim 10) takes place without complex statistical methods, rather directly on the yarn treatment, is controlled by the actual yarn and considers the machine with its (current) dynamics. you receives data from real, up-to-date information online Measured values and need not be based on simulated, outdated data To fall back on. There is a possibility during the Production to determine how productivity (the  Efficiency) would behave if one or more Tolerance bands for cleaning the yarn are changed, if necessary also separately on the respective yarn error channel.

As far as there was talk of a tolerance band, understand that the change in the upper and lower limit of the Tolerance band must not take place simultaneously, but rather each limit of the tolerance band is independent and independent is adjustable and changeable by the other, depending on the frequency of exceeding the corresponding one narrower limit of that which also consists of two limit values inner tolerance band. Tolerance band can be both absolute be understood, based on the thread size zero and two positive limits for the inner (narrower) tolerance band and two positive values for the outer (larger) tolerance band; it can also tolerances for a thread number (specified yarn thickness) can be selected as a benchmark, then a respective tolerance band consists of a positive and negative value. An inner and outer tolerance band is in defined both applications.

The number of Exceeding or falling below a respective limit understood (depending on the currently measured yarn thickness). A The limit of the inner tolerance band is exceeded to a virtual yarn error, i.e. just one count. A Exceeding a limit of the outer tolerance band leads to an actual separation, the sum of which, based on a given period of time (the frequency of virtual and real thread cuts) depending on the operating environment and the Dynamic value of the machine results in value. To form the Frequencies are sliding digitally easy to process Suitable for averaging; integrators can also do the same or low passes are used.

The invention (s) are described below with reference to several Exemplary embodiments explained and supplemented.

Fig. 1 is a function of the yarn thickness d, plotted against the yarn length L or over time t. The limits are drawn which trigger an actual yarn cut e, and those d ₃ , d ₄ which are used to optimize the aforementioned limits when the frequency R (t) of the exceedances r of the inner limits is evaluated.

FIG. 2 is a block diagram of a possible embodiment in which a target value E set _is specified in order to define the number of errors per unit of time or per yarn length. The working ability a (t) of a machine WA is also used to test error limits d ₃ , d _{4 on a} trial basis, while currently even larger error limits in a wider tolerance band d ₂ -d _{1 determine} the actual yarn cleaning during production.

Fig. 3 illustrates the change in the inner tolerance band d ₄ -d ₃ in sections A, B, C, D, exceeding these limits leads to a counting pulse. The counting pulse is only registered.

FIG. 4 illustrates different yarn error channels 60 , 61 , 62 , each of which specifies different inner limits, which can additionally result in a mixed internal tolerance limit d ₃ , d ₄ for the virtual yarn errors via a summary element Z.

Fig. 2 illustrates a circuit-technical concept for self-adaptation of a spinning machine, which as an example a or 100 generates a plurality of threads or yarns, the thickness d (t) is detected as a current value via a respective measuring device M _i (i = 0. .N) , According to the description, this control of the machine can also be used for other yarn handling, such as spools or transport.

The yarn thickness d _i (t) is fed to a respective measuring circuit 40 , which carries out a comparison with predetermined limit values d ₁ , d ₂ or d ₃ , d ₄ . The multi-stage comparator provided in the circuit 40 compares the respective yarn thickness according to FIG. 1, where the associated limit values are shown as an inner tolerance band d ₄ -d ₃ and an outer tolerance band d ₂ -d ₁ . The comparator block 40 reports that the inner tolerance band has been exceeded as a virtual yarn error r, shown in FIG. 1 and forwarded as a pulse to a counter 50 in FIG. 2. The exceeding of the outer or larger tolerance band with the upper limit d ₂ and the lower limit d ₁ is reported by the comparator block 40 as a real error e, which leads to a thread cut "e" on the respective thread 100 a. Then it is spun again. The thread cut is also registered separately from the virtual thread errors r by the counting unit 50 , and in the long term the counter block 50 outputs two frequencies, first the frequency E (t) for the number of actually occurring thread errors e per predetermined time unit and the frequency R (t) as the number of virtual yarn errors r related to a given time period.

The virtual and real yarn errors r and e are shown in FIG. 1 at their times at which they occur, namely when one of the four limit values d ₁ to d ₄ shown there is exceeded.

In FIG. 2, is shown (lower right) a traveling machine WA, which each individually produce along the spinning positions can be moved in the y direction a thread 100a with the associated velocity v _a. If a thread cut e occurs at one of the threads, the automatic walking machine WA is requested by the respective spinning station and it corrects the thread error there. The automatic walker emits a signal a (t) for general control, with which it signals its ability to work; if the value a (t) is large, then it has few demands from spinning stations, if a (t) is small, the automatic walking machine WA is very busy and is not available for additional inquiries or is only available with a time delay.

Depending on the signal a (t), an optimization can take place in a controller V or 30 to which the abovementioned frequencies E (t) and R (t) are fed. A target value E _should dictates how high the frequency may be of thread breaks or Garnschnitten, taking into account the previously signaled by hiking Maker WA for work. If the ability to work is low, only a low setpoint E _{should be} specified. If the ability to work is high, the setpoint E _{should be} higher in order to produce qualitatively better yarn; If more frequent thread cuts are accepted in this regard, narrower limits can be set, which the control V carries out via the specifications of the respective inner limits d ₃ , d ₄ and the tracking or feedback of the respective outer limits d ₁ , d ₂ .

A control cycle will be explained. The starting point is FIG. 1, in which the internal limit values at r are exceeded and this excess occurs with a low frequency R, for example for the upper limit d ₄ . The counter block 50 registers a low frequency R (t) for the limit value d ₄ . Over a longer period of several hours, e.g. B. five or six hours, R (t) is monitored by the controller V and if the value remains favorable at a low frequency, the upper limit d ₂ of FIG. 1 is reduced, best to the previously tested virtual limit d ₄ ; then there is a high probability that the same error rate R (t) that has just been measured virtually becomes the actual error rate E (t). This is based on the upper limit d ₄ or d ₂ of FIG. 1.

FIG. 3 shows a time diagram which is much longer term than FIG. 1. The axis t has a time duration of several hours and shows how the virtual limit value d _{4 changes} in the time intervals A, B, C and D changed. In the example shown in FIG. 3, the change was such that, in the longer term, the limit value d ₄ resulted in an acceptable error frequency R by the counter block 50 , so that the upper limit d _{2 could be} tracked. The internal error limit d _{4 is} adjusted at the same time or slightly delayed and made a narrower limit during the period T _B. Again, the error rate R still proved to be acceptable, that is within the specified setpoint E _should. The upper limit d ₂ is therefore tracked again and set to the value of d ₄ during the period B. The internal limit value d ₄ is then set to a reduced value again during the time period C. Here, too, the error frequency R is measured and, in the example shown in FIG. 3, it gives the result that the actual upper limit d ₂ can no longer be tracked because the frequency R was too high or the frequency of the actual error cuts E during the Time period C has risen sharply so that the upper limit d ₂ cannot remain at the value of the time period B, cannot be reduced to the virtually tested value for the time period C, but must even be increased, which is achieved by tracking the virtual upper limit d ₄ is shown for the time range D, which is lower than the actual upper limit d ₂ .

In the same way, the lower limits d ₃ , d _{1 can be} tracked, they can run synchronously with the previously described sequence example and increase continuously, which corresponds to a continuously reduced tolerance band, but they can also take other paths independently of this, depending on the associated error frequency R and E.

It is not absolutely necessary, the ability to work a of the traveling robot WA for changing the setpoint E _to zoom pull, the setpoint can also be specified control and higher ranking.

It had already been explained with reference to FIG. 3 that different errors (thick spots and thin spots) can be optimized separately. FIG. 4 illustrates this with three exemplary error channels 61 , 62 , 60 , which issue different inner limit value pairs, for N, S and L errors. These limit value pairs can either be monitored independently or can be combined in a combination element Z in order to produce a synthesized total tolerance band d ₃ , d ₄ (for the Z channel).

Claims (19)

1. Method for self-adaptation of a machine of textile processing or processing, in particular a spinning machine, winding machine or yarn processing machine, a textile thread ( 100 a) being used, in which method

• a) changeable external limit values (d ₁ , d ₂ ) of a thread thickness (d (t)) of the thread ( 100 a) are set such that no more than a first frequency (E) of thread separations (e), such as thread breaks or thread cuts , occurs in a given longer period;
• b) a measurement (M _i ) on the textile thread ( 100 a) leading to a change in the external limit values is carried out and a second frequency (R) of the exceeding (r) of limit values (d ₃ , d ₄ ) narrower than the first limit values per given one Unit of time influences the change in the external limit values (d ₁ , d ₂ );
• c) to cause an actual thread separation (only) if at least one of the outer limit values (d ₁ , d ₂ ) is exceeded (e).

2. The method as claimed in claim 1, in which an actual increase or decrease as a change in the outer limit values triggering a thread separation (e) takes place only after long-term counting ( 50 ) of exceedances (r) of the narrower limit values (d ₃ , d ₄ ). 3. The method of claim 2, wherein the long-term Counting for several hours, especially more than 5 hours takes place before a change in external boundaries he follows.   4. The method according to any one of the preceding claims, wherein at least one of the narrower limit values (d ₃ , d ₄ ) as second limit values after an actual change of an associated one of the outer limit values (d ₁ , d ₂ ) in the same direction as the associated outer limit value will be changed. 5. The method according to any one of the preceding claims, in which the narrower limit values (d ₃ , d ₄ ) do not induce or trigger thread separation (e), but only form impulses that signal an apparent - a hypothetical - thread break (r). 6. The method according to any one of the preceding claims, in which the narrower limit values (d ₃ , d ₄ ) are changed more frequently than the first limit values (d ₁ , d ₂ ). 7. The method as claimed in one of the preceding claims, in which the narrower limit values (d ₃ , d ₄ ) depend on an ability to work (a (t)), in particular an availability, of an automatic machine (WA) for eliminating a thread separation (e) occurred machine error. 8. The method as claimed in claim 7, in which the narrower limit values (d ₃ , d ₄ ) are set even more closely if the machine (WA) has a low application rate and thus a high working capacity (a (t)) to correct a fault condition of the machine. has. 9. The method according to claim 1, wherein the narrower limit values (d ₃ , d ₄ ) are adjustable and for each type of error, such as very short thick sections, short thick sections, long thick sections or thin sections, are specified separately in order to adapt themselves to either a single one of the different types of errors as error channels or a combination of several error channels. 10. The method according to any one of the preceding claims, in which the first frequency is a desired frequency (E) and as the target value (E _soll ) of thread separations is a frequency that is still tolerable for the type and mode of operation of the textile machine. 11. The method according to any one of the preceding claims, wherein the Self-adaptation takes place on a machine that is itself a Has a large number of spinning units or winding units. 12.Procedure for operationally checking new limit values for triggering thread separations of a spooled or spun thread ( 100 a), in which - compared to a first limit value, the exceeding (e) of which actually triggers a thread breakage - at least a smaller limit value (d ₃ , d ₄ ) is set and a longer-term count ( 50 ) of exceedances (r) of this reduced limit value (d ₃ , d ₄ ) a currently expected actual frequency (R) of thread breaks - without loss of yarn - is determined in advance. 13. The method according to claim 12, wherein the smaller limit value (d ₃ , d ₄ ) is gradually or gently and steadily reduced until the expected frequency (R (t)) of thread breaks is higher than a target value (E _soll ). 14. The method as claimed in claim 12, in which the reduced limit value (d ₃ , d ₄ ) is increased continuously or gently until the expected frequency (R (t)) of thread breaks is less than a predetermined target value. 15. The method according to claim 12, wherein the longer-term counting ( 50 ) takes place one or more hours before the limit values (d ₃ , d ₄ ) exceeded without actual yarn cuts are set as the external limit values that cause actual thread breaks (yarn cuts). 16. The method of claim 12, wherein two first limit values and two reduced in relation to these Limit values are used. 17. Device for independently changing a tolerance band (d ₂ -d ₁ ) having first limit values of tolerances of a yarn thickness (d (t)) tolerated without a yarn cut, in which the frequency (R (t)) of the exceeding is exceeded via a counter ( 50 ) of internal limit values (d ₃ , d ₄ ) can be determined in order to adjust the limit values of the tolerance band (d ₂ -d ₁ ) leading to the yarn cut (e) to these internal limit values (d ₃ , d ₄ ), if and insofar as it is capable of working (a (t)) of a movable (y) yarn defect remover (WA) allowed. 18. Device, workable according to one of the previous Method claims. 19. Preparation of a device for independently changing a tolerance band (d ₂ -d ₁ ) having first limit values from deviations in a yarn thickness (d (t)) tolerated without a yarn cut, in which the frequency (R (t)) via a counter ( 50 ) exceeding the internal limit values (d ₃ , d ₄ ) can be determined in order to adjust the limit values of the tolerance band (d ₂ -d ₁ ) leading to the yarn cut (e) to these internal limit values (d ₃ , d ₄ ), if and as far as it is the work ability (a (t)) of a movable (y) yarn defect remover (WA) allows.