EP0740639B1 - Process and device for detecting the winding of thread on a rotating roller - Google Patents

Abstract

The invention relates to a process and device for detecting the winding (12) of a thread on a rotating roller (1) of a winding device about which the thread is partly wound, in which there are a light source (3, 4) to direct a beam of light (5) on the monitoring region of the roller (1) which is imaged along a surface line of the roller as a strip of light (50) and a light sensor (6, 8) with an evaluation device (10). The sensor detects the light reflected (13) from a thread winding which is converted into an electric signal and can then be processed further.

Description

The invention relates to a method for recognizing a Thread winding on a rotating roller according to the generic term of claim 1 and a device for Execution of this procedure.

It is known the coil diameter of a winding body, in particular a spool of a synthetic thread to determine a pivotally arranged sensing roller. The For this purpose, the feeler roller lies on the winding body and rotates with it this. If there is a thread malfunction in the area of the feeler roller, so the thread can be wound on the feeler roller will. Such an unwanted thread winding (= winder) leads to a malfunction. The malfunction can also in a traversing device upstream of the winding head lead to a disturbance and in a short time by itself rapidly increasing volume of thread winding on the Tracer roller considerable damage to the thread winding device cause.

To the extent of the malfunction and damage as possible keeping low has already been proposed to provide a sensor plate arranged tangentially to the sensing roller. Since the sensing roller vibrates, it is necessary between an air gap between the feeler roller and the sensor plate to provide. To ensure that under all operating conditions no false alarms triggered by the sensor plate take place, the air gap must be made correspondingly large will. This leads to the disadvantage that there is already a have noticeable thread winding on the feeler roller must, so that the sensor plate triggers an alarm signal.

With this in mind, the proposal has already been made been to provide a light barrier which is parallel to the Tracer roller of the winding device is arranged. Should now wrap a thread around the sensing roller, so the received one Amount of light changed by the winder. Becomes a falls below the specified value (photocurrent), then a Alarm signal triggered.

However, this solution does not take into account that the sensing roller vibrates. The vibrations of the feeler roller are caused by radial vibrations resulting from inaccuracies of the Roundness as well as from deflections or by pressure on the Result in bobbins. Also due to play in storage, unbalance and vibration transmission through the adjacent spools of thread Such vibrations can be caused.

This solution therefore also does not provide satisfactory monitoring the feeler roller or contact roller.

Finally, it is known from DE 26 28 994 A1 for Monitoring selected length sections of a rotating one Contact roller or feeler roller with regard to thread winding from a radial distance above the roller Light source is a light beam at an angle between 0 ° and 90 ° towards a monitoring area of the roller, the reflected light by a light sensitive Collect sensor and convert it into an electrical signal. Changes in intensity of the reflected light or Scattered light caused by a winding up here measured, evaluated and to operate a thread cutting device related.

A disadvantage of the known method, of which the Invention assumes that the surveillance area essentially is punctiform and the entire length of the roller Only monitored winding device with great technical effort can be. However, this is necessary if, for example a thread winder when the traversing is stopped an unsupervised section of the shaft. It is possible by using a plurality of light sources and detector devices arranged along the roller or alternatively through a back and forth process the light source and the light-sensitive sensor device also to record such thread winders. This will, however System response time very high and the monitoring process unsuitable for high winding speeds. In addition comes that there is contamination of the roller surface the reflective properties deteriorate and a stable Working point setting is made difficult, thereby the functional reliability the known device severely limited is.

The present invention is therefore based on the object a method for early detection of an unwanted Winding up anywhere in the monitored area a rotating roller in a thread processing or to specify thread winding device which is safe and works reliably. A device is also to be specified by means of which the detection of a winding thread on a roller of such a device with high functional reliability and a short response time.

This problem is solved for a process in Preamble of claim 1 defined type according to the invention by the features of the characterizing part of claim 1. Advantageous further developments are the subject of claims 2 to 10. A detection device according to the invention a winding thread on a roller of a winding device is the subject of claim 11. Advantageous further developments the device are the subject of the claims 12 to 20.

The method according to the invention opens a new path to Detection of thread winding on a rotating, partial walked on by the thread wound roller. It is proposed to do this by a light source Beams of light at an angle of incidence a to a surface line to project the roller onto the roller in such a way that this over the entire length of the surveillance area The roller extends as a strip of light and this from the thread winding reflected scattered light by means of a sensor device to detect and trigger an alarm signal, if at least a thread wrap in the monitoring area of the roller has been determined. The position of the light sensor results themselves from the claims.

The procedure is based on the following train of thought:

Through a preferably substantially vertical arrangement the evaluation device with respect to the monitoring area of the Radial vibrations of the roller have no influence on the detection of the thread. This may result in already found a single thread wrap on the roller will. However, an arrangement of the light sensor is also possible in other areas. The measure, the roller with a grinding incidental, parallel or yourself Irradiating widening light beam offers in particular the advantage that the entire surveillance area between two normal planes at a distance from each other Roller is set with a single light source and associated imaging optics is illuminated when the angle of attack a is correctly set to the roll surface. This depends on the amplitude of the vibrations of the Roll in winding operation, the manufacturing tolerances at Manufacture of the roller and the height of any existing Thrust rings on the roller. This angle of attack α lies in Range between 3 ° and 10 °, preferably at 5 ° and in individual cases on the basis of the structural conditions Attempt found. A winder is detected therefore simultaneously throughout the surveillance area in the state of the art only a selective detection by successive measurements was possible. The finding of the thread then takes place in that the thread, which from a plurality of filaments, light reflects and as it were on the roller of the thread winding device flashes. This flashing is from the evaluation device recognized as scattered light and then triggered a signal. Irradiation of the sensing roller over the entire surveillance area with a grinding light beam therefore make sure that the thread flashes, even if there are one or a few turns, there the roller itself emits little light towards the light sensor reflects and therefore the incident stray light as a deviation from any existing basic radiation is recognized.

The light is preferably monochrome. The roller can e.g. B. be irradiated by means of a laser light source. This is not necessary, but it has the advantage of possibly required lens systems of imaging optics easier to be able to interpret, because the monochrome light a uniform Has wavelength and corrections to the lenses only for this uniform wavelength must be taken into account. Also can be disturbed by external influences of the day or Ambient light can be switched off more easily with filters. A laser light source is preferably an inexpensive one Possibility of a sharply defined light beam monochrome To provide light. Electronic laser light sources that working in near-infrared wavelength ranges are for preferred the present invention.

Known rolls of thread winding devices have several axially spaced, raised thrust rings to when changing the bobbin for threading or Thread change to set favorable speed ratios. To ensure that there are none next to the thrust rings unlit areas and in the "shadow" of the Thrust rings arising thread winding also recorded are proposed according to claim 6, the roller with two essentially in one plane and at an axial distance to irradiate oppositely arranged light sources and thus the entire surveillance area - also immediately next to the thrust rings - to illuminate. This results in an arrangement of the sensor according to claim 6 and preferably according to claim 8.

It should be noted that the roller is the thread delivery or thread take-off roller (godet) of a filament spinning machine can be. However, it is preferably the contact or Tracer roller of a thread winding device in such a Spinning machine for synthetic filament threads, the basic one Structure, for example, from US-A-5,029,762 is known.

To detect thread winding on a rotating Roller of a thread winding device becomes a device proposed an optoelectric device (light sensor) has, which in a preferred embodiment in essentially in the middle of the surveillance area and with Distance is arranged on the side of the roller that is not is wrapped in the thread, as well as an evaluation device, which triggers a signal. The optoelectric device is preferably electrical with the evaluation device connected.

Due to the optoelectric device, this is done by one Thread winding on the rotating roller reflected light (Scattered light) is detected and fed into an evaluation device preferably standing electrical signal converted, the evaluation device when exceeded a tolerance limit triggers another signal at which it is an alarm signal or a thread cutting signal can act.

In particular, however, the device comprises an outside of the surveillance area arranged light source, the one Beams of light in the longitudinal direction of the roller and under one small angle of attack to the roller aimed at this. The Light source preferably emits monochrome light, for example the light of a laser light source. For example, it can a rectangular in cross section or a Monitoring area adapted, expanded with suitable optics Be a bundle of light.

The optoelectric device preferably comprises one Imaging optics with one arranged behind a converging lens Light sensor. The light sensor can be a CCD array or a photodiode.

The use of a sensor in the form of a CCD array the advantage that this is read out according to the clock signal can be. By knowing the axial position of the Thrust rings on a roller, especially a sensing roller Thread take-up device can measure the measured values of the light sensor (Interference reflections) from this area easily with digital logic be hidden. The electronics enable one quick response to errors in the millisecond range can lie.

Further advantages and features of the method and the device are described using an exemplary embodiment.

Fig. 1

eine schematische Anordnung der Tastwalze eines Spulkopfes mit einer Einrichtung zur Wicklerüberwachung;

Fig. 2

eine modifizierte Einrichtung gemäß Fig. 1 mit einer anderen Anordnung des Lichtsensors;

Fig. 3

das von der Lichtquelle auf eine Mantelline der Walze und das von der Walze reflektierte Lichtbündel in einer Radialebene der Walze.

Show it:

Fig. 1

a schematic arrangement of the sensing roller of a winding head with a device for winder monitoring;

Fig. 2

a modified device of Figure 1 with a different arrangement of the light sensor.

Fig. 3

that from the light source onto a surface line of the roller and the light beam reflected from the roller in a radial plane of the roller.

On the shaft or roller 1, the z. B. a diameter of 85 mm, several thrust rings 2 are formed. These come with the chuck shaft, not shown stretched bobbin tubes after a bobbin change in contact.

The feeler roller 1 is at a distance from the feeler roller by means of two and arranged opposite to each other, in one Radial plane lying light sources 3, 4 irradiated. Of the Angle of attack a, under which the beam of light or rays 5 occurs on the feeler roller 1, is chosen so pointed that each area of the optoelectric device (light sensor) 6 - 8 facing side of the surveillance area the roller 1 is illuminated. The light sources 3, 4 emit a light beam 5 with a rectangular cross section a width of about 10 mm and a depth of a few mm, preferably 1 mm. This is done with, for example achieved collimator optics, not shown, the includes cylindrical lenses. The light beam 5 is in each case in the monitoring area of roller 1 as a line or as in The circumferential direction of the roller is very narrow, along a surface line running light band 50 projected onto the roller. To cover the entire monitoring area 20 between two in the Spaced normal planes of the roller 1 is formed, To illuminate, the light sources 3, 4 are on the side outside of the monitoring area 20.

Is substantially perpendicular to the axis of rotation of the feeler roller 1 at a distance from the sensing roller 1, an optoelectric device (Light sensor) 6 - 8 essentially in the center the monitoring area 20 of the roller 1. The facility comprises a converging lens 7, behind which a light sensor 8 is arranged. The light sensor 8 is made of photodiodes built up the striking light into a photo stream 15 convert. A mask 9 is arranged in front of the light sensor 8, which hides the area of the thrust rings 2.

The light sensor 8 is equipped with an evaluation device 10 and these are electrically connected to an alarm display device 11.

Loops around a thread that z. B. at a speed of 8000 m / min runs, the feeler roller 1 and forms one Winder 12, this reflects this from the light sources 3, 4 emitted light. Furthermore, light rays of the Beam of light 5 on the fine capillaries of the filament threads hunched. The reflected light 13 strikes through the converging lens 7 on the light sensor 8. This gives a signal 15 to the evaluation device 10, which with a signal R is compared, which corresponds to a fault-free state. The evaluation device then triggers an alarm signal when in a comparison a deviation occurs that is larger is as a permissible tolerance range.

The present invention eliminates the undesirable Winding a thread on a feeler roller 1 over the early detection of the entire length of the monitoring area 20, especially after one or a few loops, so that a thread cut can be triggered before consequential damage arise on the winding machine.

Very short response times can be achieved with photodiodes will. Response times of one microsecond can be achieved. The actual response time depends on the amount of from the thread winding 12 reflected light. That's why should the angle of attack α and the width of the Roller 1 directed light beam 5 kept as small as possible become, for example 5 ° or less or narrower than 1 mm.

With a CCD sensor consisting of 1024 pixels and works with a clock frequency of 15 megahertz is one maximum response time of 70 microseconds to be expected.

The response times of both possible sensors are clear less than 2 milliseconds. This response time is sufficient at winding speeds of 8000 m / min and at one Tracer roller diameter of 85 mm for consequential damage to the to avoid endangered components of the winding device.

2 shows a modified device for winder monitoring according to Fig. 1. There is the image from the Perspective of the incident light beam 5, which from the Light source 3 via an optical system which comprises the lenses 16, 17 on the feeler roller 1, not shown here is projected. The reflected light 13 is through deflected the convex surface of the lens 17 and on the opto-electrical evaluation device (light sensor) 7 - 8 depicted in the beam path of the reflected light rays 13 is arranged, this detected and in a photo stream 15 converts. As in FIG. 1, this becomes the evaluation device 10 supplied and there for example with a Signal R compared to the photo stream 15 by the intensity of the reflected light from a feeler roller 1 without thread winding corresponds. The difference signal is in the Evaluation device 10 then amplified and can be exceeded an alarm device of a predefinable threshold value 11 or the like.

The advantage of the arrangement according to FIG. 2 is that no components of the monitoring device in the immediate vicinity Must be attached close to the feeler roller 1 to be monitored, so that the designer has greater freedom in terms of housing, assembly and maintenance of the light source 3 (Transmitter) and the light sensor 7, 8 (receiving part) and the has an intermediate look.

However, it should be noted that in the presence a second light source - to illuminate the entire surveillance area and to avoid shadowing next to possible thrust rings - the two Light sources 3, 4 in mutually offset, parallel Layers should be arranged to allow direct irradiation of the light reflected on the surface of the feeler roller to avoid opposite light sensor.

3 finally shows a schematic arrangement in FIG a radial plane of the roller 1, which in the present case has no thrust rings, for example the location of the Light source 3 with respect to the roller 1, namely outside of Monitoring area 20 of this roller. It also shows that Assignment of the light sensor 6-8 to detect the at an im Monitoring area 20 possible thread winding 12 generated Flare. This stray light is created by reflection, Diffraction and refraction of the incident light beam 5 to the fine filament threads (capillary threads) of the thread winding, the are predominantly opaque. For an arrangement according to Figure 3 can the light sensor 6-8 is arranged on the side of the roller 1 be above the roller 1, d. H. above the tangential plane the roller 1, in which the light band 50 lies. Exceptions to this are hatched in the drawing shown areas of the light source the roller 1 directed light beam 5 and of the Roller 1 reflected light bundle 25. In an angularly offset Level, the light sensor 6-8 can be arranged anywhere be. It only has to be guaranteed that the light sensor 6-8 that arises on a thread or a thread winding Scattered light and not that reflected by the roller 1 itself Beam of light measures and as a deviation of a photo stream clear differences in light intensity can be determined.

Claims (20)

1. Method of detecting spooling (12) of a yarn (= lap formation) on a rotating roller (1), around which a yarn is partially looped, wherein the light beam of a light source (3, 4) is directed onto a monitoring region of the roller (1) in that the light source (3, 4) is disposed outside of the monitoring region and directed obliquely onto the monitoring region,

   and wherein the light reflected from the monitoring region is detected by a light sensor (6-8), and the light source (3, 4) and the light sensor (6-8) are situated at the side of the roller around which the yarn is not looped,

   characterized in that

   the light beam (5) is directed onto the roller (1) in such a way that it appears as a light band (50) along a surface line of the roller (1) and covers the monitoring region,

   and that the light sensor (6-8) is disposed outside of the light beam (5) directed by the light source (3, 4) onto the monitoring region (20) and outside of the light beam (5) reflected by the roller (1).
2. Method according to claim 1,
   characterized in that

   the light band (50) has a width of less than 5 mm, preferably less than 2 mm.
3. Method according to claims 1 to 2,
   characterized in that

   the light beam (5) is directed onto the roller (1) at an angle of incidence α of between 3 and 8°, preferably of approximately 5°.
4. Method according to claims 1 to 3,
   characterized in that

   the shaft (1) is irradiated with monochrome light.
5. Method according to claim 4,
   characterized in that

   the light beams (5) are the light of a laser light source.
6. Method according to claims 1 to 5,
   characterized in that

   the roller (1) is irradiated by means of two light sources (3, 4), which lie opposite one another, by in each case one light beam (5) in such a way that a substantially common light band (50) appears on the roller (1) in the monitoring region (20), and that the light sensor (6-8) is disposed outside of the light beams (5) directed by the light sources (3, 4) onto the monitoring region (20) of the roller (1) and outside of the light beams (5) reflected by the roller (1).
7. Method according to one of claims 1 to 6,
   characterized in that

   the roller (1) is the feeler roller of a yarn spooling device for synthetic filament yarns.
8. Method according to claims 1 to 7,
   characterized in that

   the light sensor (6-8) for detecting the light reflected by spooling (12) of the yarn is disposed substantially centrally above the monitoring region of the roller (1).
9. Method according to claim 1,
   characterized in that

   the light sensor (6-8) for detecting the light reflected by spooling (12) of the yarn is disposed in the beam path parallel to the light source (3) emitting the light beams (5).
10. Method according to claim 9,
    characterized in that

    the light received by the light sensor (6-8) is acquired as an electrical signal (15) and the variation of said signal is amplified for triggering an alarm signal.
11. Device for detecting spooling (12) of a yarn (lap formation) on a rotating roller (1) of a yarn processing or yarn spooling device for implementing the method according to claims 1 to 10, having a light source (3, 4) for irradiating the roller (1) in a monitoring region and having a light sensor (6-8) for detecting the light reflected from the monitoring region,
    characterized in that

    the light source (3, 4) is directed towards the monitoring region (20) of the roller (1) at such an angle of incidence α that in the monitoring region a light band (50) appears along a surface line of the roller (1) and covers the length of the monitoring region, and that the light sensor (6-8) is disposed outside of the light beam (5) directed by the light source (3, 4) onto the monitoring region (20) of the roller (1) and outside of the light beam (5) reflected by the roller (1).
12. Device according to claim 11,
    characterized in that

    the angle of incidence (α) of the light source (3) relative to the axis of rotation of the roller (1) is between 3 and 10°, in particular 5°.
13. Device according to claim 11 or 12,
    characterized in that

    the roller (1) is irradiated by the light source (3) with monochrome light, which is preferably emitted by a laser light source.
14. Device according to claims 11 to 13,
    characterized in that

    two light sources (3, 4) are directed towards the monitoring region (20) of the roller (1) at such an angle of incidence α that a substantially common light band (50) appears in the monitoring region (20) of the roller (1) and covers the length of the monitoring region (20),

    and that the light sensor (6-8) is disposed outside of the light beams (5) directed by the two light sources (3, 4) onto the roller (1) in the monitoring region (20) and outside of the light beams (5) reflected by the roller (1).
15. Device according to claims 11 to 14,
    characterized in that

    the light sensor (6-8) comprises a collecting lens (7), which is disposed in the beam path of the light beam (5) reflected by the spooling (12) of the yarn.
16. Device according to claims 11 to 15,
    characterized in that

    the light sensor (8) comprises a CCD array.
17. Device according to claims 11 to 15,
    characterized in that

    the light sensor (8) comprises a photodiode.
18. Device according to at least one of claims 11 to 17, in which the roller (1) comprises a plurality of axially spaced stop rings (2),
    characterized in that

    a mask (9) is disposed in the beam path between the collecting lens (7) and the light sensor (8).
19. Device according to one of claims 11 to 18,
    characterized in that

    the roller (1) is the feeler roller (1) of a yarn spooling device or is a yarn feeding galette of a spinning machine for synthetic yarns.
20. Device according to claim 11,
    characterized in that

    the light sensor (6-8) is disposed in a plane, which is parallel to the plane, in which the light source (3) directing the light beam (5) onto the roller (1) is situated.

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