EP0282745A1 - Method and apparatus for the control of production and quality at working positions of multispindle textile machines - Google Patents

Abstract

A common monitoring device (5, 6) is provided for at least two production sites (21, 22, 23, 24) and has a radiation beam (7). This is guided by the thread balloon formed by the running thread (1, 2, 3, 4) from each of the relevant production sites (21, 22, 23, 24) and is intermittently interrupted or weakened by the running thread in each balloon. The resulting shading is converted into an electrical signal in the receiver (6) of the monitoring device. The threads of the individual production sites can be identified by evaluating the amplitude, time and phase relationships between the individual shading pulses. The process enables on-line production and quality monitoring on multi-spindle textile machines, for example ring spinning machines, at a reasonable cost.

Description

There are a large number of production machines in the textile industry on which a large number of production sites are used at the same time. Spinning machines, winding machines or twisting machines can be cited as examples. There is an obvious need to automatically monitor each and every one of these manufacturing sites for production flow and quality. From the point of view of the production process, above all, thread break monitoring is desired, and from the point of view of quality monitoring, the determination of the thread cross-section and / or its unevenness. In the case of twisting machines, the cross-section of the twine is of particular interest to check whether all threads are twisted.

Even if "thread" is always mentioned in the following explanations, this term should not be understood as restrictive, but as representative of all spinning products, such as yarns, threads, filaments and the like.

The above-mentioned monitoring of all individual production sites can be technically solved by known means, but has not yet been implemented for reasons of cost. The large number of production sites allows only a minimal cost per production site, so that the effort per machine remains within a reasonable range.

For thread break detection on ring spinning machines, systems have recently appeared on the market which have so-called traveling sensors. The movement of the ring traveler on an entire side of a ring spinning machine can be detected with a single sensor. This solution for thread break detection is cost-effective. However, it is not possible to measure other thread parameters because the signal is generated by the rotating ring traveler and not by the thread itself.

To date, no economical solutions have been implemented on ring spinning, twisting and similar machines for determining the thread cross-section and / or its unevenness directly at the production site.

The invention is now to provide a method which enables production and quality monitoring of the production sites on multi-spindle textile machines at a reasonable cost.

The invention relates to a method for production and quality monitoring of the production sites on multi-spindle textile machines, the production sites being arranged in rows and that of each product tional running thread executes a transverse movement in the manner of a balloon and thereby envelops a rotationally symmetrical body referred to below as a spatial element.

The method according to the invention is characterized in that a common monitoring device is provided for at least two production sites, which has a radiation beam, that the radiation beam is guided through the spatial elements at the at least two production locations and is intermittently interrupted or weakened in each spatial element by the moving thread and that the resulting shading is converted into an electrical signal in a receiver and used as a basis for further evaluation.

The basic idea of the invention is therefore to monitor several production sites with a common monitoring device, whereby the costs per production site are reduced accordingly. One bundle of rays is thus guided through several thread balloons, the cross-section of the thread bundle preferably being selected to be small in relation to the balloon diameter. In the operating state of the textile machine, each thread now crosses the bundle of rays twice per revolution. There is a high probability that there is only one thread in the beam at any given time. The smaller the number of production sites, the greater the probability. However, it is absolutely essential that each thread, alone and alone, traverses the beam; otherwise the measurement would be disturbed. Because the rotational movements of the individual threads are usually not exact synchronous, but coincidental, the case of the detection of each individual thread with certainty occurs over time.

In the case of textile machines with a very large number of production sites in a row (for example over 100), it makes sense not to pass the light beam through all the balloons, but to form several groups. The size and number of these groups is a matter of discretion and is determined by practical parameters. Above all, the likelihood that there is only a single thread in the beam will decrease with a large number of production sites, and furthermore the light intensity may no longer be sufficient if the transmitter and receiver are at a greater distance. The latter of course does not apply to laser beams.

The invention further relates to a device for performing the above-mentioned method with a monitoring device. The device according to the invention is characterized in that at least two production sites are assigned a common monitoring device, which has a transmitter for a radiation beam and a receiver for the latter and is arranged such that the radiation beam penetrates the spatial elements at the at least two production sites, and that means for Evaluation of the intensity fluctuations of the radiation beam occurring at the receiver are provided.

• Fig. 1a einen schematischen Grundriss einer Anzahl von Produktionsstellen,
• Fig. 1b eine Seitenansicht der Produktionsstellen von Fig. 1a, von links gesehen,
• Fig. 2 ein erstes Impulsdiagramm,
• Fig. 3a,3b eine erste Variante der Anordnung von Fig. 1a im Grundriss bzw. in Seitenansicht,
• Fig. 4 ein zweites Impulsdiagramm,
• Fig. 5 eine zweite Variante der Anordnung von Fig. 1a im Grundriss,
• Fig. 6 ein drittes Impulsdiagramm,
• Fig. 7 eine dritte Variante der Anordnung von Fig. 1a im Grundriss,
• Fig. 8 ein konstruktives Detail einer Produktionsstelle,
• Fig. 9-11 je eine weitere Variante der Anordnung von Fig. 1a im Grundriss,
• Fig. 12 Beispiele von Impulsformen,
• Fig. 13 Beispiele von Fadenlagen im Strahlenbündel, und
• Fig. 14 eine weitere Variante der Anordnung von Fig. 1a im Grundriss.

The invention is explained in more detail below on the basis of exemplary embodiments and the drawings; shows:

• 1a shows a schematic floor plan of a number of production sites,
• 1b is a side view of the production sites of Fig. 1a, seen from the left,
• 2 shows a first pulse diagram,
• 3a, 3b a first variant of the arrangement of Fig. 1a in plan or in side view,
• 4 shows a second pulse diagram,
• 5 shows a second variant of the arrangement of FIG. 1a in plan view,
• 6 shows a third pulse diagram,
• 7 shows a third variant of the arrangement of FIG. 1a in plan view,
• 8 shows a constructive detail of a production site,
• 9-11 each another variant of the arrangement of Fig. 1a in plan,
• 12 examples of pulse shapes,
• Fig. 13 examples of thread layers in the beam, and
• Fig. 14 shows a further variant of the arrangement of Fig. 1a in plan.

1a and 1b schematically show four production stations 21, 22, 23 and 24, which are spindles of a ring spinning machine. With 10 the ring bench, with 11 the ring, with 12 a thread guide (the so-called "Sauschwänzchen") and with 16 a spindle. At each production point, a thread 1, 2, 3, 4 runs from the thread guide 12 to the ring 11 and thereby forms a thread balloon 13 in which it occupies a current position 31, 32, 33 and 34, respectively.

The four production sites 21 to 24 arranged in rows are assigned a common monitoring device, which has a transmitter 5 for a light beam 7 and a receiver 6 for this. The bundle of rays 7 is guided through the center of the balloons 13 and is thus continuously traversed by the threads 1 to 4 as they rotate, namely twice per revolution. A corresponding shading occurs with each crossing at the receiver 6.

In the textile machines in question, the rotation speed of all the balloons on the same machine is approximately the same, but is not synchronous. The time for one revolution is thus at least approximately known. If, as in the example shown, with a monitoring device for four production sites, shading has occurred eight times (2 times 4) for one revolution, all the threads are still intact.

2 shows a corresponding pulse diagram in which the time t is plotted on the abscissa and the shading A, which results from the threads 1, 2, 3, 4 in the beam, is plotted on the ordinate. Each shading by one of the threads 1 to 4 is symbolized by a corresponding shading pulse A1 to A4, A1ʹ to A4ʹ. The pulse train is purely random, but is always offset by a half-cycle of 180 °.

The guidance of the beam 7 through the center of the balloons 13 is only one example. The beam of rays can, for example, also be displaced in parallel or be guided obliquely according to FIGS. 3a, 3b, wherein it includes an angle a with the horizontal H and an angle b with the connecting line K of the axes of the production sites 21, 22, 23, 24.

Several beams can also be used for certain purposes. A plurality of beams can also be formed by a single light transmitter 5 and a plurality of light-sensitive receivers 6, 6ʹ (FIG. 5), or a plurality of light transmitters 5 and a single light-sensitive receiver 6. The following explanations are limited to just a few examples. The diameter of the thread can be inferred from the time course and the intensity of the shading pulse.

First, the explanations are limited to the detection of thread breaks; Additional explanations, which are necessary for the determination of the thread cross-section, are given at the end of the examples.

The task is only partially solved when a thread break is detected within a production group. The second part of the task is to identify the position of the production points 21, 22, 23, 24 where the thread breakage has occurred, i.e. the identification of the production site.

This object can be achieved, for example, with an arrangement according to FIG. 3a. The beam 7 no longer traverses the thread balloons through their center, but at different distances from the center. In contrast to FIG. 1, in which a possible thread break is determined after exactly half a rotation period, differences can be found in this example. It is easy to see that the pulse spacing corresponds to an angle c or d. A corresponding pulse diagram is shown in FIG. 4. This shows how the different which angles present in the pulse diagram. For the sake of clarity, the angle d is not entered; it represents the addition of the angle c to 360 °.

The interpretation of the individual impulses, i.e. their togetherness is not particularly easy. If there is enough time for the evaluation, the problem can be solved with the help of statistics. As a rule, it is the case that a thread break does not necessarily have to be detected during the first round; If the number of revolutions is large enough, the non-synchronous running of the individual production sites will result in shifts again and again, so that according to the laws of statistics, e.g. autocorrelation, correct assignments are possible. Determining the thread that caused shadowing can be made considerably easier if a second beam is used. As shown in FIG. 5, this can be achieved by using a transmitter 5 and two receivers 6, 6,, or by using two transmitters and a receiver. In both cases, two diverging or converging beams 7, 8 are obtained. Of course, two transmitters 5 and two receivers 6 can also be used.

Since, as already mentioned, the speed of rotation of all the balloons is approximately the same, the position of the production points 21, 22, 23, 24 can be recognized perfectly from the time between the two beams 7, 8 traversing the thread. 5, the impulses for the spindle 21 are obviously very close to one another, while the greatest displacement is present for the spindle 24. The shift corresponds speaks an angle e (e1, e2, e3, e4) and the assignment is obvious. FIG. 6 shows the corresponding pulse diagrams of the shadows in the two beams 7, 8.

However, it could also happen here that multiple interpretations in the spindle assignment would be possible due to coincidences. However, it is possible to limit yourself to the clearly assignable spindles in a first run and to carry out further measurements at one or more later times when the position of the threads is completely different. The probability of the size of the time interval within which the presence of all threads can be determined can be calculated according to the laws of statistics.

In order to make the determination of the belonging of the individual shading impulses to the relevant spindles even clearer and simpler, the arrangement of FIG. 5 can be modified according to FIG. 7. According to the illustration, a further transmitter 25 is arranged between the two receivers 6, 6 Fig (FIG. 5) and a further receiver 26, 26ʹ on each side of the transmitter 5. As a result, the balloons are traversed by two pairs of beams 7, 8 and 7ʹ, 8ʹ. The evaluation of the shading pulses to the receiver 6, 6, and 26, 26 Auswertung is carried out for each pair of receivers in the manner described with reference to FIGS. 5 and 6, the signals of the two pairs of receivers being related to one another. This makes the assignment of the shading impulses to the individual spindles clearer and more reliable, but on the other hand the effort is also greater.

In many production machines, the individual production sites are separated from one another by separators. This is shown in FIG. 8 using the example of a ring spinning machine. The balloon 13 is formed as in FIG. 16 between the thread guide 12 and the ring 11 on the ring bench 10, which also carries an opaque separator 14 for each spindle. In addition, the spindle 16 is longer than in FIG. 1b, so that the beam 7 cannot be placed centrally through the balloon 13, at least not in its lower part. In this case, the beam 7 lies laterally next to the spindle 16, just above the cop structure, and the separator 14 has corresponding recesses 15 for the beam to pass through. FIG. 9 shows a possible position of two beams 7, 8 next to the spindles 16.

Fig. 10 shows the arrangement of Fig. 9 in even greater detail. 17 denotes a radiation emitter, for example a luminescent diode, the arrow 18 denotes the direction of the beams 7, 8. Such beams are generally wide-ranging (with the exception of laser beams). The rays thus also strike the receiving elements 19 and 20. These can be commercially available photodiodes. The beam 7 now arises between the transmitter 17 and the receiving element 19, the beam 8 between the transmitter 17 and the receiving element 20. In this way, electrical pulses are generated, as shown in FIGS. 2, 4 and 6. Basically, the time shift enables the identification of the production site, while the size of the shading corresponds to the diameter of the thread.

The processing of electrical impulses is well known and therefore need not be described in detail. However, it should be mentioned that the shading represents a voltage or a current pulse that is easy to measure. The time difference between the pulses is pure time measurements that can be determined very precisely with simple means. Voltage or current can easily be converted into binary signals, and together with the time measurement, ideal conditions for electronic data processing arise; microprocessors are particularly suitable.

In FIGS. 1a, 3a, 3b, 5, 7 and 9, they are only schematically entered as a straight line with a punctiform cross section. In practice, the cross-section of the beams 7, 8 is determined on the one hand by the luminous surface of the transmitter 17 and on the other hand by the surface of the receiving elements 19 and 20. If these areas are approximately the same size, the impulses of the individual production sites are independent of their position, which simplifies the evaluation.

However, it is also possible, as indicated in FIG. 11, to consciously design, for example, the transmitter 17 over a small area and a receiving element 19 over a large area (or vice versa). This also makes it possible to identify the production site from the pulse length and / or from the pulse height. This makes pulse evaluation slightly more complex, but only a single light transmitter and a single receiving element are required. FIG. 12a shows a pulse as it is generated in principle by the production site 21 from FIG. 11, and FIG. 12b shows a corresponding pulse from the production site 24 (FIG. 11).

In the examples described, only four production locations are shown. However, this number can easily be increased, but is limited by the reliability of the assignment of a pulse to the corresponding production site, which decreases with an increasing number of spindles. As a rule, the upper limit of the number of production locations is likely to have been reached at approximately 16 production locations. In a machine with, for example, 160 production sites, 10 groups of 16 production sites would have to be formed. With the individual groups, only a minimal effort is necessary because the evaluation is preferably carried out centrally. In this way, inexpensive systems can be built.

The number of production sites can further be limited by problems with the optics, since the light intensity decreases with the square of the distance from the receiver to the transmitter. Disturbing light and noise can cover up the useful signal. A considerable improvement is possible if the light is modulated in a known manner. External influences can thus be eliminated.

The previous statements have been limited to the detection of thread breaks. The size of the shading is also a measure of the diameter of the thread in the relevant beam. Even if the transmitter and receiver areas are of the same size, the intensity of shading is not only dependent on the diameter, but also on the position of the thread between the transmitter and receiver. This is illustrated with reference to FIG. 13. The transmitter 17 sends its light to the receiver 19 and the thread 1 is located directly at the receiver 19 (FIG. 13b). In this case the shading is almost equal to the diameter of the thread 1. In FIG. 13 a, the thread 1 is drawn approximately in the middle between the receiver 19 and the transmitter 17. It is quite obvious that the shadowing in this case is greater (almost double). This property can be used to identify the production site of the thread in question if it can be assumed that the thread diameter is sufficiently constant (or an average of several passes is formed).

A given position corresponds to a precisely defined shading for a given diameter. If the thread diameter changes as a result of irregularities, the size of the shading also changes. Since the thread also runs through the balloon in the longitudinal direction, a different point in the thread is always scanned. The known quality parameters, such as the coefficient of variation of the non-uniformity, the spectrogram, etc. can be calculated from a sufficient number of sampling points. A seamless pulse train is not necessary. Interruptions are permitted because there is enough material and time for an "on-line" measurement.

In the case of twists, it is necessary in various cases to check that all individual threads are present. If a single thread is missing or if there is an excess thread, the diameter of the thread changes and with it the shading. From this it can be determined whether the number of individual threads in the thread is correct.

 It is also conceivable that a different thread count is produced by a mix-up at a production site. In this case, there is always a different shade from the production site in question than with a thread of the right fineness. This means that even production sites with incorrect thread count can be identified.

If the size of the shading is included in the evaluation, it is not only inexpensive to produce a thread break detection, but also to achieve comprehensive quality monitoring of each individual production site.

Finally, FIG. 14 shows yet another possibility for the position of the bundle of rays through the balloons, in that the beam 7 is thrown back from the transmitter 5 onto a mirror 9 and from there as a reflected beam 7ʹ onto a receiver 6. Pulse sequences similar to those in the example according to FIG. 5 arise. However, only one transmitter and one receiver are necessary here. However, the length of the beam 7 is twice as long.

Claims (14)

1.Procedure for monitoring the production and quality of the production sites on multi-spindle textile machines, the production sites being arranged in rows and the thread running at each production site executing a transverse movement in the manner of a balloon and thereby enveloping a rotationally symmetrical body referred to below as a spatial element, characterized in that A common monitoring device (5, 6, 6ʹ; 17, 19, 20) is provided for at least two production sites (21, 22, 23, 24), which has a beam (7, 7ʹ, 8, 8ʹ) that the beam is guided through the room elements (13) at the at least two production points and is intermittently interrupted or weakened in each room element by the moving thread (1, 2, 3, 4), and that the shading generated thereby is in a receiver (6, 6ʹ , 19, 20) is converted into an electrical signal and used as the basis for further evaluation. 2. The method according to claim 1, characterized in that each monitoring device (5, 6, 6ʹ; 17, 19, 20) is assigned more than two, preferably four to eight, production sites (21, 22, 23, 24). 3. The method according to claim 2, characterized in that the beam (7) is guided through the axis of the associated spatial elements (13). 4. The method according to claim 2, characterized in that the beam (7) is guided parallel to the connecting line (K) of the axes of the spatial elements (13) and at a distance therefrom. 5. The method according to claim 2, characterized in that the beam (7) is guided obliquely against the horizontal (H) and / or obliquely against the connecting line (K) of the axes of the spatial elements (13). 6. The method according to any one of claims 3 to 5, characterized in that the identification of the individual threads (1, 2, 3, 4) of the production points (21, 19, 20) monitored by a monitoring element (5, 6, 6ʹ; 17, 19, 20) , 22, 23, 24) by evaluating the time intervals (c1, c2, c3, c4) between the individual electrical signals generated by the shading. 7. The method according to any one of claims 3 to 5, characterized in that the identification of the individual threads (1, 2, 3, 4) of the production points (21, 19, 20) monitored by a monitoring element (5, 6, 6ʹ; 17, 19, 20) , 22, 23, 24) by evaluating the amplitude and / or duration of the electrical signals generated by the shading. 8. Device for carrying out the method according to claim 1, with a monitoring device, characterized in that at least two production points (21, 22, 23, 24) are assigned a common monitoring device (5, 6, 6ʹ; 17, 19, 20), which a transmitter (5, 17) for a beam (7, 8) and a receiver (6, 6ʹ, 19, 20) for this and is arranged in such a way that the beam of rays penetrates the spatial elements (13) at the at least two production sites and that means are provided for evaluating the intensity fluctuations of the beam of rays occurring at the receiver. 9. The device according to claim 8, characterized in that each monitoring member (5, 6, 6ʹ; 17, 19, 20) is assigned more than two, preferably four to eight, production sites (21, 22, 23, 24). 10. The device according to claim 9, characterized in that the monitoring member has a first transmitter (5, 17) for transmitting a diverging beam (7, 8) and two first receivers (6, 6ʹ, 19, 20) for this. 11. The device according to claim 10, characterized in that on both sides of the first transmitter (5) two second receivers (26, 26ʹ) and between the two first receivers (6, 6ʹ) a second transmitter (25) is arranged so that the spatial elements (13) are penetrated by two beams (7, 8; 7ʹ, 8ʹ) extending in the opposite direction. 12. The apparatus according to claim 9, characterized in that the transmitter (5) and receiver (6) are arranged side by side, and that a mirror (9) for reflecting the beam of rays emitted by the transmitter (7) is provided on the receiver. 13. The apparatus according to claim 12, characterized in that each spatial element (13) is penetrated both by the emitted by the transmitter (5) as well as by the beam (7 or 7ʹ) reflected by the mirror (9) onto the receiver (6) . 14. The apparatus according to claim 9, for use at production sites mutually shielded by opaque separators, characterized in that the separators (14) have corresponding recesses (15) for the passage of the beam (7).

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