EP1041184A2 - Device for monitoring yarn webs in knitting, weaving or warp preparation machines - Google Patents

Abstract

The assembly to monitor bands of warp yarns has at least two lasers (L1-L4) with their light beams (44,46,48,50) aligned at least at two receivers (E1-E4). The lasers (L1-L4) are controlled by signals through a common line (42), separately from the receivers (E1-E4) and/or the receivers (E1-E4) transmit their signals through a common line (52) separate from the lasers. All the lasers (L1-L4) are controlled by signals through a common line (42), and all the receivers (E1-E4) transmit their signals through a common and separate line (52). The signals are coded to control a laser and the transmitted signals from a receiver. T laser or receiver is controlled through a timing pulse signal, where the control signals for the separate lasers or receivers ar coded in a set time sequence in the timing pulse signal. At the end of the common line, the timing pulse signal is passed to an active distribution unit, to be passed to the different lasers (L1-L4). The lasers (L1-L4) and/or receivers (E1-E4) are switched series. Their control and/or transmitted signals each pass through delay or signal processing units for signal modification. Two lasers can be controlled through one line, and two further lasers through a second line, with a timed cycle alternation between two lines. The receivers, in pairs, pass their transmitted signals through two lines with a common line for each pair. The laser beam, at each laser, is divided optically into at least two part-beams. In an assembly with two lasers, each delivering a laser to two facing receivers, the lasers are at different gaps from the band of warps.

Description

The invention relates to a system for monitoring thread groups in knitting, weaving or warp preparation machines, with at least two lasers each emitting a laser beam and at least two recipients, each with at least one Laser beam strikes.

In the textile industry, threads are produced, rolled up, and processed into fabric on weaving or knitting machines. Both at Warp preparation machines as well as weaving and knitting machines A large number of threads run in parallel in sets of threads. Here it happens that one of the threads breaks. It is important, that then the broken thread is recognized as quickly as possible, so the appropriate machine can be stopped to prevent that scrap is produced.

To detect a broken thread, it is common to use light barrier systems to be used, usually laser light barriers. The laser beam is guided close to the thread sheet, and a broken thread gets into the laser light beam or is directed there and generates a signal in the Evaluation logic. The deflection of the broken thread into the laser light beam is sometimes supported by fans.

Especially with fibrillating threads it can lead to disturbances of the Light barrier coming through fiber particles in the air. To avoid false alarms, two laser light barriers are therefore often used arranged close to each other. To the textile machine then switch off both laser light barriers within a defined time (e.g. 50 ms to 500 ms) the thread be interrupted.

This doubles the number of laser light barriers required. Since several thread coulters in more complex machines The number of laser light barriers to be used must be monitored high.

In such known laser light barrier systems are in generally two individual laser light barriers in pairs assigned, with each transmitter and each receiver one individual light barrier with its own signal-carrying line and with a control unit for generating and evaluating the respective measurement signals is connected. The control unit for the In turn, light barriers are controlled by a controller Textile machine connected to this upon detection to turn off a broken thread. An arrangement of a such a laser light barrier system is schematic in Fig. 1A reproduced. The use of mapped Laser light barriers for monitoring a thread do not increase only the number of laser light barriers to be used, but also the amount of required signal-carrying lines to the Transmitters and receivers of the laser light barriers.

For each laser light barrier, lines must be connected to the laser light beam emitting laser and moved to the receiver become. With warp preparation machines, such as warping gates approx. 600 to 700 m multi-pole cables, for warp knitting machines approx. 150 m multi-pole cables are required. The each required cable lengths doubled if two Photoelectric sensors can be used to monitor a thread.

The cables and routings are only on site at End customers relocated. Prefabricated in the right length, Multi-core cables cannot be used because of the different Textile machines are built very differently. The cable lengths are used for reasons of economy in warehousing held in 10-meter pieces. When laying there are always unsightly cable loops that are expensive must be accommodated.

With winding, warping, winding or twisting machines it is also common each of the myriad threads through a small one Monitor light barrier. Here inevitably for those for the cables required wiring found their own solution become. DE 197 22 701 A1 provides a device for Monitor a variety of threads before using multiple detector devices (Light barriers) via a common bus line can be controlled by a control device. This bus line is with the lasers of the light barriers as well connected to the receivers (no separate cables), and the lasers are activated in a first signal phase, and received signals are transmitted in a second signal phase. Such a solution with a bus line is available from much larger light barrier systems with which entire thread groups if only because lasers are used here are not monitored and the receiver are too far apart to to be controlled via a common bus line.

When using multiple light barriers to monitor Threads in a textile machine require signals individual transmitter-receiver pairs of a light barrier can be distinguished to detect. This way, for example Component tolerances of the transmitter and receiver are taken into account. Usually the individual light barriers in the Pulse mode controlled, so the influence of extraneous light to suppress or reduce.

It is an object of the present invention to assemble a Simplify investment of the type mentioned.

This task is carried out by a system for monitoring thread groups solved in knitting, weaving or warp preparation machines, the at least two lasers each emitting a laser beam and has at least two receivers, on each of which a laser beam strikes, with the laser by control signals over a common line, separated from the receivers and / or the receiver output signals via a common, Give up the line separate from the lasers.

Another solution to the task is a monitoring system a group of threads in knitting, weaving or warp preparation machines with a transmitter that emits a laser beam and at least one receiver onto which the laser beam at least partially strikes, the one emitted by the laser Laser beam through an optical device in at least two Partial beams is split.

In both solutions, the one required for the cables Cabling effort significantly reduced.

The above first variant of the invention is advantageously designed such that that all lasers have a first common line are controlled and all receivers via their output signals submit a second common line, using either the assignment the control signals to a transmitter or the assignment of the output signals to a receiver via a coding of the Signals.

The lasers or the receivers are preferably replaced by a Clock signal driven, the individual transmitter or receiver encoded in the clock signal by a predetermined time sequence are.

It is also possible to control the laser transmitters using a clock signal, that at the end of a common line on one unit is routed to the active distribution with which the clock signal is distributed to different laser transmitters, or a unit provide with the measurement signals detected by different receptions become.

The lasers and / or the receivers are preferably at least partially connected in series and the control signals and / or the output signals each run through an allocation unit, which is suitable for each transmitter and / or receiver Generates signal and passes the signal modified so that the following sender and / or receiver does it for him Process ("recognize") the appropriate signal and for the one following it Transmitter or receiver in the same way a signal can pass on, etc. Preferably, the allocation unit be a delay unit.

Figur 1A

Eine bekannte Anordnung von Lasern und Empfängern und deren Verkabelung mit einem Steuergerät sowie einer Textilmaschine;

Figur 1B

die übliche Anordnung von zwei Laserlichtschranken neben einer Fadenschar;

Figur 1C

eine andere Anordnung der beiden Laserlichtschranken bezüglich der Fadenschar;

Figur 2A

den Verlauf des Laserlichtstrahls in Laser und Empfänger bei einer konventionellen Laserlichtschranke;

Figur 2B

den Verlauf des Laserlichtstrahls bei einer erfindungsgemäßen Laserlichtschranke;

Figur 2C

eine schematische Darstellung einer Laserlichtschranke mit erfindungsgemäßer Aufteilung eines Laserstrahls und eines Signalverlaufs eines erfindungsgemäßen Empfängers bei Detektion eines gerissenen Fadens;

Figur 3

eine erfindungsgemäße Anordnung von Lasern und Empfängern und ihrer Verkabelung;

Figur 4A

ein uncodiertes Taktsignal;

Figur 4B

ein codiertes Taktsignal zur Ansteuerung der Laser;

Figur 5

eine weitere Alternative der Erfindung, bei der ein Taktsignal auf eine Einheit zur aktiven Verteilung des Signals auf verschiedene Laser geleitet wird;

Figur 6A

eine weitere Austührungsform einer erfindungsgemäßen Anlage aus Lasern und Empfängern;

Figur 6B

eine weitere Ausführungsform einer erfindungsgemäßen Anlage aus Lasern und Empfängern mit einer anderen Art der pulsverzögerten Ansteuerung der Laser;

Figur 7A

eine weitere Ausführungsform einer erfindungsgemäßen Anlage aus Lasern und Empfängern mit einer Art der pulsverzögerten Ansteuerung der Laser;

Figur 7B

die die Laser steuernden Ansteuersignale,

und

Figur 7C

die von den Empfängern ausgegebenen Ausgabesignale.

In the following, some embodiments of the invention are described in detail with reference to the drawings. Show it:

Figure 1A

A known arrangement of lasers and receivers and their cabling with a control unit and a textile machine;

Figure 1B

the usual arrangement of two laser light barriers next to a thread sheet;

Figure 1C

another arrangement of the two laser light barriers with respect to the thread sheet;

Figure 2A

the course of the laser light beam in the laser and receiver in a conventional laser light barrier;

Figure 2B

the course of the laser light beam in a laser light barrier according to the invention;

Figure 2C

a schematic representation of a laser light barrier with the inventive division of a laser beam and a signal curve of a receiver according to the invention upon detection of a broken thread;

Figure 3

an inventive arrangement of lasers and receivers and their wiring;

Figure 4A

an uncoded clock signal;

Figure 4B

a coded clock signal for driving the laser;

Figure 5

another alternative of the invention in which a clock signal is passed to a unit for actively distributing the signal to different lasers;

Figure 6A

a further embodiment of a system according to the invention consisting of lasers and receivers;

Figure 6B

a further embodiment of a system according to the invention of lasers and receivers with a different type of pulse-delayed control of the lasers;

Figure 7A

a further embodiment of a system according to the invention consisting of lasers and receivers with a type of pulse-delayed control of the lasers;

Figure 7B

the control signals controlling the lasers,

and

Figure 7C

the output signals output by the receivers.

Figure 1B schematically shows a common arrangement of two one Thread group 10 monitoring laser beams 12 and 14. Tears Thread 16 of the thread sheet 10, it moves into the area of the two laser light beams. If these are both within one certain time (50 ms to 500 ms) interrupted, so there the system for monitoring the thread group sends a signal to the Textile machine to stop them. With this arrangement the two laser light beams run at the same distance the thread cluster 10.

FIG. 1C shows a further possible arrangement of the laser light beams 12 and 14 according to an aspect of the present invention. In this case, the second laser light beam 14 is wider away from the thread sheet 10 as the first laser light beam 12. If a thread 16 breaks, it first interrupts the first Laser light beam 12, and only then the second laser light beam 14. This gives you another, more reliable one Criterion to switch off the machine, it does not have to only both laser beams are interrupted, but the first one Laser light beam 12 must be interrupted before the second laser beam (weakened).

Figure 2A shows a common arrangement of a laser 18 with optical components and a receiver 20 including optical Components. A laser source 22 sends a laser beam 23 made of an aperture 24 with an opening 25 meets. The laser beam passing through the opening 25 27 passes through a lens 26. The beam 27 passes through the area the light barrier and then hits the receiver 20 first on a lens 28, which focuses it on a sensor 30.

Figure 2B now shows an embodiment of the invention. Also here a laser beam 23 is emitted by the laser source 22. This meets an aperture 32 with two openings 34 and 36. A first partial jet 38 runs through the opening 36, and a second partial beam 40 through the opening 34. Here too the two partial beams 38 and 40 leave the laser via one Lens 26, pass through the area of the light barrier and hit on the lens 28 of the receiver 20, from which it points to the sensor 30 to be focused.

Depending on the position of the laser 18 with respect to the thread sheet the two partial beams 38 and 40 are oriented as the two laser light beams 12 and 14 in Figure 1B or so in Figure 1C.

By dividing the laser beam 23 into the two partial beams 38 and 40, a single laser 18 can handle the laser beams for two light barriers. This will not only Cabling effort halved for the lines, it must be for a variant of the invention in which the Rays are arranged as shown in Figure 1c, only a laser and a receiver can be used and adjusted.

As shown in Figure 2C, a transmitter and a receiver a light barrier according to the invention arranged so that the split laser beam 23, i.e. H. its partial beams 38 and 40, are detected by the receiver. Since the two Partial beams 38 and 40 hit the receiver at the same time, are two pulses with a time interval from the receiver detects when a broken thread the two partial beams 38 and 40 interrupts. The time interval between the two detected pulses is determined by the distance between the two partial beams 38 and 40 and the speed of the partial beams 38 and 40 interrupting thread. The amplitude of the two Detected pulses depend on the diameter of the thread the partial beams 38 and 40 interrupts.

It should be noted that the arrangement of the two Partial beams 38 and 40 corresponds to an arrangement which with the Arrangement of the laser light beams 12 and 14 from Figure 1C comparable is. This means that the two partial beams 38 and 40 are different spaced from a group of threads to be monitored have to be. Since there is only one receiver to detect the two Partial beams 38 and 40 is used is an evaluation of the Sequence of interruptions of partial beams 38 and 40 not possible due to a broken thread.

Another embodiment of the invention is shown in FIG. 3. Four Lasers L1, L2, L3 and L4 are connected via a common line 42 controlled and emit laser beams 44, 46, 48 and 50, the hit the receivers E1, E2, E3 and E4. Give the latter their output signals via a common line 52. The two lines 42 and 52 are separated from each other. Frequently will be limited to two lasers over one to control common line, as some technical characteristics the light barrier and its sensitivity setting, Level display, noise display when connected in parallel are coupled together.

If one wants to evaluate the channels separately in the arrangement of FIG. 3, the signals passed over lines 42 and 52 contain information about which of the four light barriers they are assigned. The coding and assignment of the signals can be such that it takes place on the laser side, the signal e.g. not all lasers L1 to L4 activated at the same time. On the other hand the coding can also be done on the receiver side. In In this case, all lasers L1 to L4 are activated at the same time, however, the evaluation electronics in the control unit recognize on the basis the coding in the receiver analogous to the coding on the Transmitter side, which light barrier and thus which output signal is relevant.

For example, the coding may look like the laser or the receivers are controlled by a clock signal, such as it is shown in Figure 4A without coding. Here it is Clock signal from positive rectangular pulses 54, each of which have half the length of a clock period T.

The signal is encoded in FIG. 4B. Interruptions positioned in time Place 56, 58 and 60 in the rectangular pulse 54 here the coding represents. For example, a time Interruption 58 in the front of the rectangular pulse 54 the laser Go to L1, a break a little further back 56 the laser L2, and the laser far behind Interrupt the laser L4 of Figure 3. Other variants of the Coding is conceivable, for example this can be a clock signal designated regular signal also, according to a predetermined Time sequence must be coded. The lasers or receivers have each via electronic means to "recognize" the coding and to respond to the coding so that the Computers processing receiver signals each have information receives which measurement signal belongs to which light barrier.

The result of this embodiment is that the decoders of the individual laser L1 to L4 or the receiver E1 to E4, which the Recognize coding, cannot be identical, since yes each laser or receiver responds to a different coding got to.

Figure 5 shows another way in which all lasers and receivers including their electronic control means can be identical. Here are exemplary (only) two lasers L1 and L2 shown, the laser light beams 62 and 64 to the Send out receivers E1 and E2.

A clock signal 66 with rectangular pulses 68 like that shown in Figure 4A becomes active via a line to a unit 70 Distribution directed. This unit can be, for example Flip-flop or a ring counter. The unit 70 now distributes the clock signal to the two lasers L1 and L2 so that each second rectangular pulse 68 is supplied to laser L1, and each other rectangular pulses are fed to the laser L2. To an ordinary distribution runs to the active distribution unit 70 Clock signal over a common line, which then turns on the lines leading to lasers L1 and L2 are distributed. Since this distribution takes place in the vicinity of the laser, it is reduced the amount of cabling required for the lines considerable here too.

Decoding logic can also be used instead of the unit 70 become. This becomes pulses such as that in Fig. 4B shown, and it decodes and routes the corresponding signals to the individual lasers.

Another embodiment of the invention, in the identical Laser and receiver can be used is shown in Figure 6A shown.

The lasers L1, L2, L3 and Ln, the laser light beams, are shown 72, 74, 76 and 78 to receivers E1, E2, E3 and En send out. Each of the lasers L1, L2, L3 and Ln is located a delay unit 80, 82, 84 and 86, respectively Rectangular pulse 88 is supplied to laser L1 via line 90. The laser L1 is controlled accordingly. The delay unit 80 delays the square pulse 88 and sends it delayed rectangular pulse over line 92 to laser L2. This is delayed due to the delayed rectangular pulse activated. In the delay unit 82, the rectangular pulse 88 further delayed and is via line 94 to the laser L3 fed, which is activated later in time. Finally the laser Ln is activated. The lasers L1 to Ln are therefore in Series switched. In contrast, the receivers E1 to En are parallel switched, an evaluation unit can due to the time Sequence of signals an assignment by the receiver output signals to the individual recipients make.

Alternatively, time delay elements can also be used on the receiver side or coding elements can be provided to the signals of each Distinguish between light barriers.

In a modification of the embodiment described above can also receive the signals from the individual light barriers on the receiver side discriminated against one another (differentiated), by for each receiver in the evaluation electronics (the computer) a separate time window is specified for the signal to be evaluated becomes.

In a further embodiment of the invention, which is shown in FIG 6B, instead of the delay units 80, 82, 84 and 86 from FIG. 6A signal processing units 80 ', 82 ', 84' and 86 'are used, which consist of a corresponding one Cable 90, 92, 94 and 96 fed signal sequence SF1, SF2, SF3 and SF4 each have a first signal to control a use the assigned laser L1, L2, L3 or L4 and the remaining signals of the respective signal sequences SF1, SF2, SF3 and SF4 to a correspondingly assigned other Forward laser.

As shown in Figure 6B, cable 90 is preferred from a control unit for the laser light barrier system according to the invention after a start pulse SD a first signal sequence SF1 sent to the first laser L1. The number of each corresponds to signals encompassed by the first signal sequence SF1 the number of lasers in a light barrier system according to the invention the embodiment of Figure 6B can be used. Since there are four lasers in the example shown in FIG. 6B L1, L2, L3 and L4 are used, comprises the first signal sequence SF1 four individual signals, preferably four individual transmit pulses SP1, SP2, SP3 and SP4. The first signal processing unit 80 'for the first laser L1 uses the first transmit pulse SP1 to drive laser L1 so that it emits a laser beam delivers. The start pulse SP received via line 90 and the Transmit pulses SP2, SP3 and SP4 are sent to the signal processor Unit 82 'for laser L2 forwarded via line 92. The signal processing unit 82 'controls by means of the second transmission pulse SP2 the laser L2 for emitting a laser beam and conducts the received start pulse via line 94 SP and the transmit pulses SP3 and SP4 to the signal processor Unit 84 'for the laser L3 further. The signal processing Unit 84 'uses the third transmission case SP3 to transmit the To control and direct laser L3 to emit a laser beam via line 96 the start pulse SP and the fourth transmit pulse SP4 to the signal processing unit 86 'for the laser L4 further, which is initiated by means of the fourth transmission pulse SP4, to deliver a laser beam.

For continuous operation of the laser light barrier system according to the invention 6B using the previously enable the pulse-delayed control of the lasers described, 90 start pulses together with a following corresponding signal sequence continuously supplied.

Since all the signals supplied via line 90 are preferably in a control unit for the light barrier system according to the invention are generated, not only the synchronization of the used Laser improved, but the centrally generated signals can also improve the synchronization of the receiver be used.

Figure 7a shows another possible arrangement. This exists consisting of two double light barrier systems, each with a laser L1 and a laser L2, the laser light beams 96, 98, 100, 102 send to receivers E1, E2, E3 and E4. The laser L1 of the first double light barrier system and the laser L2 of the second Double light barrier systems are via a common line 104 controlled. Accordingly, the second laser L2 of the first double light barrier system and the first laser L1 of the second double light barrier system via a common line 106 controlled. The receivers E1 and E2 of the first double light barrier system give their output signals over a common line 108 and the receivers E3 and E4 des second double light barrier system give their signals via a common line 110 from. So here, too, halves required wiring effort for the lines the state of the art, in which all lasers and receivers each can be controlled via a line.

FIG. 7B shows the control signals that are sent via the lines 104 and 106 are supplied. The control signals exist each from a rectangular pulse 112 with a period T is fed, and its length is a quarter of this period is. This is shown in the lower part of Figure 7B. This lower signal is used for control via the line 104, the upper signal is supplied via line 106. The upper signal has the same shape as the lower signal is but offset in time by half a period. When added together, these signals give a clock signal like that in FIG 4A.

An output signal is now shown in FIG. 7C, as described above line 108 or line 110 is output. From the Dash 113 shown in dashed lines becomes a sequence 114 of individual Pulses 115, 116, 117, 118. The pulses 115 and 117 can assigned to laser L1 (or to receiver E1 or E3), pulses 116 and 118 can be sent to laser L2 (or the receiver E2 or E4) can be assigned.

The arrangement of Figure 7A can also be applied to systems with more than two double light barrier systems are transmitted. Signals such as shown in Figure 7B are via a first line fed to one laser of each double light barrier, and the corresponding time delay is carried out via a second line Signals to the second laser of the double light barrier fed. With every double light barrier Signals of the two receivers are carried away via a common line. The saving of the wiring effort required for the cables is therefore larger on the laser side than on the receiving end.

In generalization of the principle according to the invention, with an arrangement of m transmitter lines and n receiver lines n times m light barriers operated with separate signal evaluation with each of the transmitter lines being one from the other distinguishable (coded) signal.

Combinations of the different embodiments are possible. For example, in the embodiment of Figure 7A Delay unit as in Figure 5 in front of lines 104 and 106 may be switched, or line 106 could be in series behind the upper laser L1, which is then connected with a Delay unit is equipped so that the signal initially ran over line 104, over the different Laser, and then as shown in Figure 7A would run the delayed signal on line 106 over which the other lasers can be controlled.

All double light barriers can have one instead of two receivers single large-area receiver can be used.

If here of "common lines" for the laser or the The recipient is talking about, this means the actual tax and Signal lines or signal-carrying wire pairs of an electrical Line or cable. In addition, you can still click on Earthing cables are provided on each side (laser or receiver side) his.

Claims (8)

System for monitoring thread coulters in knitting, weaving or Warp preparation machines, with at least two laser beams each emitting lasers (L1, L2, L3, L4) and at least two Receivers (E1, E2, E3, E4), each with a laser beam (44, 46, 48, 50), characterized in that the laser (L1, L2, L3, L4) by control signals via a common, separate line (42) can be driven by the receivers and / or the receivers (E1, E2, E3, E4) output signals via a Deliver common line (52) separate from the lasers. Installation according to claim 1, characterized in that all Laser (L1, L2, L3, L4) via a first common line (42) are controlled and all receivers (E1, E2, E3, E4) their output signals deliver via a second common line (52), where either the assignment of the control signals to a laser or the assignment of the output signals to a receiver via the signals are encoded. System according to claim 1 or 2, characterized in that the lasers or the receivers by a clock signal (FIG. 4A) can be controlled, the signals for the individual lasers or receiver by a predetermined time sequence (56, 58, 60) in the clock signal are encoded. System according to claim 1 or 2, characterized in that the lasers (L1, L2) are controlled by a clock signal (66), that at the end of a common line to a unit for active Distribution (70) is routed with which the clock signal (66) is distributed to different lasers (L1, L2). System according to claim 1 or 2, characterized in that the lasers (L1, L2, L3, Ln) and / or the receivers (E1, E2, E3, En) are connected in series and the control signals and / or the output signals each by a delay unit (80, 82, 84, 86) or signal processing unit (80 ', 82', 84 ', 86 ') to modify the signal. Installation according to claim 1, characterized in that two Lasers can be controlled via a first line (104), two further lasers can be controlled via a second line (106) and one measure alternately over the first and the second Line and that two receivers (E1, E2, E3, E4) Output signals via a common two receivers deliver third and fourth lines (108, 110). System for monitoring a family of threads in knitting, weaving or Warp preparation machines with a laser beam emitting Laser (18) and at least one receiver (20) on the the laser beam strikes at least partially, characterized in that that the laser beam emitted by the laser through an optical device (32) in at least two partial beams (38, 40) is divided. System for monitoring a thread group (10) in knitting, weaving or Warp preparation machines, each with two laser beams (12, 14) emitting lasers and two receivers on each a laser beam strikes, characterized in that the two laser beams emitted by the lasers are not in run the same distance from the thread sheet (10).

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