DE3603649A1 - System for monitoring the thread feed on winding machines, especially for the roving-winding technique - Google Patents

Abstract

What is proposed is a monitoring system for winding machines, especially in the roving-winding technique, which indicates the break or absence of a thread, without being connected to the machine drive. Each individual thread is assigned a thread-movement indicator (3) having a binary output signal (A). A reference signal (B) is obtained as a result of the logic interlinking (21) of all the output signals. The fault indication occurs when there is antivalence of the reference signal (B) with at least one output signal (A). Time elements (19, 20) prevent incorrect fault indications. Thread-movement indicators (3) of electro-optical design are preferably arranged between the thread magazine and the next following thread guides. <IMAGE>

Description

The invention relates to a system for monitoring the Thread feeding in winding machines, especially for the Roving winding technology. This technique makes great use Special machines for processing glass, coal and other fibers to high-strength hollow bodies, the wound fiber strands with casting resin or other Glued plastics and thereby to a very tough Structures are solidified compared to steel is much easier. The threads (rovings) are in front of the Application pulled through a plastic bath. For certain Applications are machines that simultaneously 80 and wind more threads and this from a corresponding number of bobbins deduct, not uncommon.

Does one of these threads break or become damaged during the Winding one or the other bobbin empty, that's it manufactured and usually highly stressed component unusable. Check for thread breakage and Coil emptying is therefore of great importance.

Thread tension monitors with a spring are known loaded lever, which is a deflection eyelet or roller for the Has thread at the end of the lever and when the Thread tension returns to its rest position, which then triggers an interference signal. Any redirection or friction of the However, rovings are highly undesirable as this will break of single fibers or other damage can.

Thread movement monitors are also known, in particular in Form of low wrap angle and less Impact force of the thread-driven rollers, their Rotation is sensed. If the thread breaks, it stays Roll stand and an interference signal is derived from it. However, these interference signals also occur  Breaks in the winding machine. To suppress the Signals should have a dependency between that Machine drive and the monitoring system created become annoying and the usability of the Monitoring system for different machines in question poses.

The invention has for its object a system to propose with the help of it without functional coupling with the machine drive and without the threads a certain minimum voltage can be determined, whether a thread is broken or as a result of emptying the bobbin is not present.

This object is achieved in that a thread motion detector with binary Output signal is assigned that by logical Linking of all motion detector output signals Reference signal is obtained and that in the event of antivalence Reference signal and at least one motion detector Output signal a fault is reported. The The basic idea of the invention is therefore that disorder of interest to recognize that at least one thread is different in movement than the others Threads. So if a motion detector comes to a standstill signaled and the rest of the movement, so lies in Thread channel of this one motion detector the fault. On the other hand, there is clearly a malfunction if one motion detector signals motion, the others but not all also signal movement. In this In case the fault location is correct with the concerned one Motion detectors do not match. The contemplation of However, the entirety of all motion detectors will prove that signals at least one standstill, so that the Fault can be located here. So it becomes useful  be the motion detector in the event of a fault signal to indicate the standstill signals.

A preferred embodiment of the invention exists in that the size of the motion detector as the output signal "0" the thread standstill and the size "L" the Thread movement is assigned to the logical link is an OR operation and that every motion detector an AND gate with two inputs is assigned, the Reference signal to one input and the relevant one Motion signal after inverting the other entrance.

Alternatively, an AND link could also be selected, however, the output variable "L" is the thread standstill to assign and invert the reference signal. In In both cases, the motion detector gives this Fault signal, the thread of which is actually broken or is not present.

With two other conceivable design options, namely OR operation, standstill corresponds to size "L", Motion detector signal is in front of the two-pole AND gate inverted or AND operation, standstill corresponds Size "0", reference signal is inverted, solve the Thread motion detector with the thread running Fault report off, but the fault itself is with the To locate the thread channel, whose motion detector is at a standstill signals. The fault location is circuitry no problem, for example through appropriate Inverting the output signals of the AND gates.

It is also appropriate to use the individual thread movement detectors to add a timer each, which for a short time Thread standstill the relevant output signal  prevented. Depending on the winding process or the shape of the can be wound on the mandrel during the winding process regularly come to a short thread standstill with the other threads stop matches. The timer prevents in these cases incorrect fault signals.

Similarly false fault signals could occur when the Winding machine occur because of the output signals of the Thread motion detectors never for tolerance reasons appear exactly at the same time. It will therefore suggested that the logical link, provided that is an OR operation, followed by a timer which suppresses the reference signal until all threads have clearly started to move.

In the interest of the independence of the Monitoring system from the winding machine drive and Machine type, it is advantageous to use the thread motion detector on the thread magazine near the relevant bobbins to arrange or between the thread magazine and the next eyelet or pulley. An arrangement in the Near the drop eye, where the thread is soaked with plastic does not come in because of the pollution Consider.

The arrangement of the motion detector close to the magazine raises problems where the thread is not from one braked supply spool is pulled off the outside, but stationary so-called internal take-off coils are provided. Here the thread has practically no tension when pulling it out, so that for the usual mechanical thread motion monitors Deflection rollers, thread brakes u. Like. To be installed. To avoid this, it is proposed that smooth, especially electro-optical thread motion detectors are provided.  

It is therefore independent of the winding machine drive Thread monitoring system created that without any bullying gets along in the thread path. A kit-like design allows the use in winding machines any Type. The practically non-contact, but at least Low-friction thread motion detectors can be found near the Thread magazines are installed and are suitable especially for internal take-off coils.

An embodiment of the invention is as follows explained using the drawing. In detail shows

Fig. 1 roughly shows schematically the behavior of a thread from the bobbin to the winding mandrel,

Fig. 2 is a logic diagram of an embodiment of the monitoring system and

Fig. 3 is a schematic spatial representation of an electro-optical thread motion detector.

According to Fig. 1, the thread ( 1 ), which can also have the form of a band and is referred to in the glass fiber winding technology as roving, is pulled out of a fixed inner take-off spool ( 2 ). It passes through an electro-optical thread movement detector ( 3 ), a thread brake ( 4 ), and is then wetted with casting resin with the aid of rollers ( 5 ) which are immersed in a casting resin container ( 6 ). This is followed by a so-called dancer ( 7 ) to maintain the thread tension, consisting of two fixed deflection rollers and one deflection roller which is attached to a spring-loaded lever. Finally, the thread is wound onto a driven mandrel ( 9 ) from the movable laying eye ( 8 ), from which the finished hollow body is pulled off after curing. It should be noted that in reality in such winding machines a large number of corresponding arrangements for many threads are provided in parallel next to each other, wherein certain individual components can also be designed together for several or all threads. In any case, however, a thread movement detector ( 3 ) is assigned to each individual thread.

Referring to FIG. 2, four yarn motion detector (3) are shown, for example. They emit a signal of the size "0" when the thread is at a standstill or if the thread is missing and a signal of the size "L" when the thread is moving without interference. Each thread motion detector is followed by a timer ( 20 ) which delays the edge of the standstill signal by about 500 milliseconds. All output signals ( A ) of the timing elements ( 20 ) arrive at a common OR gate ( 21 ), which is also followed by a timing element ( 19 ), the output signal of which is referred to as the reference signal ( B ). Each thread movement detector is also assigned an AND gate ( 22 ) with a normal and a negated input. The output signals ( A ) are each fed to the negated input, while the reference signal ( B ) is at the other input. If a signal of size "L" occurs at the output of one or more of the AND gates ( 22 ), this means a fault, ie thread breakage or emptying the bobbin of the thread concerned. In the example, lamps ( 23 ) are indicated as a fault indicator. The fault can also be activated acoustically or by stopping the winding machine.

The reference signal ( B ) has the size "L" if at least one of the threads is running. In contrast, the size "0" corresponding to the stationary thread is antivalent. The negation of the signal ( A ) at the input of the relevant AND gate ( 22 ) makes this constellation recognizable in the form of a fault signal at the output of the AND gate.

Fig. 3 indicates the design of an electro-optical thread motion detector. Two stacked housing halves ( 24 ) leave a guide channel ( 25 ) with a rectangular cross section between them. A photocell ( 26 ) and a light source ( 27 ) are inserted at the bottom into a bore that penetrates the guide channel. A roving ( 28 ) passes through the guide channel ( 25 ) with plenty of play. In contrast to the state when the roving ( 28 ) is at a standstill, a transverse oscillation of the roving is observed when the roving is moving, in particular at high speed, which results in a clearly measurable change in the output signal of the photocell ( 26 ). If there is no thread, the signal difference compared to the running roving is even clearer. The photocell signal is evaluated with electronic means (not shown) and, depending on the size and the vibrations present, a logically usable output signal is obtained, for the "movement" state on the one hand and for the "standstill or missing thread" state on the other.

• 1 thread
  2 internal take-off spool
  3 thread motion detectors
  4 thread brake
  5 roll
  6 cast resin containers
  7 dancers
  8 drop eye
  9 thorn
  19 timer
  20 timer
  21 OR
  22 AND
  23 lamp
  24 housing half
  25 guide channel
  26 photocell
  27 light source
  28 roving
  A output signal
  B reference signal

Claims (6)

1. System for monitoring the thread feeding in winding machines, in particular for the roving winding technology, characterized in that a thread motion detector ( 3 ) with a binary output signal ( A ) is associated with each individual thread ( 1 ), that by logically linking all motion detector output signals Reference signal ( B ) is obtained and that a malfunction is reported if this reference signal and at least one motion detector output signal are non-equivalent. 2. System according to claim 1, characterized in that as the output signal of the motion detector ( 1 ) the size "0" is associated with the thread standstill and the size "L" of the thread movement, that the logical link is an OR link ( 21 ) and that each motion detector ( 3 ) is assigned an AND gate ( 22 ) with two inputs, the reference signal ( B ) being applied to one input and the relevant motion detector signal ( A ) being inverted to the other input after prior inversion. 3. System according to claim 1, characterized in that the motion detectors ( 3 ) are each followed by a timing element ( 20 ) which prevents the relevant output signal in the event of a short, particularly due to the winding process, thread stoppage. 4. System according to claim 2, characterized in that the OR link ( 21 ) is followed by a timing element ( 19 ) which suppresses the reference signal ( B ) when the winding machine starts up until all threads have started to move. 5. System according to claim 1, characterized in that smooth, in particular electro-optical thread motion detectors ( 3 ) are provided. 6. System according to claim 5, characterized in that the thread movement detector ( 3 ) in the thread path between the thread magazine ( 2 ) and the next thread guide ( 4 ) are arranged.