EP1679277B1 - Method and device for the operation of a workstation of a textile machine producing crosswound bobbins - Google Patents

Description

The invention relates to a method for operating a workstation of a cross-wound textile machine according to the preamble of claim 1 and to an apparatus for carrying out the method according to claim 4.

In order to produce a textile bobbin, it is known that it is necessary, on the one hand, to set the relevant textile bobbin in rotation and, on the other hand, to traverse the thread running on the bobbin along the bobbin axis. By relatively fast traversing of the thread can be created a so-called Kreuzbewicklung.
Such cheeses are characterized not only by a relatively stable bobbin, but also by a good flow behavior.
With regard to the winding of such cheeses, a distinction is made between the winding type "wild winding" and the winding type "precision winding" or "step precision winding".

In particular, in connection with the winding type "wild winding" are often so-called thread guide drums in use, not only traversing the incoming thread but also simultaneously form a peripheral drive for the cross-wound bobbin.

However, such thread guide drums are not applicable to produce a precision or stepped precision winding, since in the production of these types of winding of the drive Cheese and drive the Fadenchangiereinrichtung must be separated.
That is, in the manufacture of a cheese in the winding type precision or step precision winding the cheese is driven by a separate spool drive and laid the incoming thread through an additional, separately driven Fadenchangiereinrichtung.

For example, devices have proven to be very suitable for a fast and positionally precise thread switching whose parallel to the axis of rotation of the cheese displaceable yarn guide is connected via a traction means with a reversible single drive or facilities that work with a so-called finger thread guide or wiper, that is, yarn guide, which have a finger-like thread-laying lever which is pivotable about a substantially perpendicular to the cheese axis arranged axis over a certain angular range.

In the DE 100 21 963 A1 a workstation of a cheese-producing textile machine is described in which a rotatably held in a creel sleeve by a drive roller having a separate drive, can be rotated.
The job also has a traversing yarn guide, which is fixed to an endless belt and can be guided back and forth by a defined controllable single drive within a changeable in its length traverse stroke.
The single drive of the traversing yarn guide is coupled with an angle encoder, which detects the rotor position of the electric motor and reports to a controller.

In the DE 100 21 963 A1 However, no detailed information about the exact design and operation of the angle encoder used are included.

The WO 00/24663 describes a Fadenchangiereinrichtung with a finger thread guide, the drive to a sensor device, a so-called rotary encoder is connected, which monitors the movement of the finger thread guide. It is stated in this patent application that in order to check the system state and if necessary to correct the rotary encoder, it is occasionally returned to a reference point.

To refer to the encoder while various non-contact sensors can be used.

However, the Fadenführerarm can also be brought into contact with a mechanical stop, wherein the corresponding output signal of the encoder is evaluated to give a reference for the positioning.

Also by the DE 198 58 548 A1 is a job for a cheese-producing textile machine known in which the reel drive and the Fadenchangiereinrichtung have separate drives.
The Fadenchangiereinrichtung is designed as a finger thread guide, which is acted upon by an electromagnetic drive.
The electromagnetic drive of the thread guide drive is controlled by a microprocessor, which controls the current strength and the current direction according to a predetermined program angle and time-dependent that results on the Traversierbreite the respectively desired laying angle of the thread or that set the traverse width or the traversing points targeted can be.
For detecting the instantaneous angle, an infrared light barrier is used, which scans marks arranged coaxially to the oscillating axis.
However, such optical sensor devices are not entirely unproblematic due to the known in spinners and winders often heavily loaded with dust and fluff air.
That is, such optical sensor devices require to work largely trouble-free, a relatively high cleaning costs.

The post-published DE 103 54 587 describes a job of a cheese-producing textile machine, which has a creel for holding a rotatable package and a finger thread guide for traversing a supplied thread has.
The electromotive single drive of the finger thread guide is equipped with an angle sensor which is connected to a workstation computer and has a pivotally mounted permanent magnet and a stationary Hall IC element.
Such an angle sensor has several advantages.
The relatively inexpensive analog Hall IC element, which is influenced by the magnetic flux of a pivotally mounted permanent magnet, generates, for example, voltage values which are proportional to the angular position of the permanent magnets and thus to the angular position of the finger thread guide and which can be well processed by the workstation computer.
These delivered during traversing the thread-laying lever of the thread guide voltage signals have in the area covered by the finger thread guide range between about -40 ° and + 40 ° also has a nearly linear course.
Since such angle sensors work contactless and thus wear-free, they are also characterized by a long service life.
It is also positive that such angle sensors have only a relatively low moment of inertia and therefore can be used reliably at high traversing speeds.

In the EP 1 125 877 A1 a winding head module for a rotor spinning machine is described.

The winding head module in this case has a single-motor driven coil drive roller and also a single-motor driven Fadenchangiereinrichtung.

The Fadenchangiereinrichtung equipped with a finger thread guide is equipped with an angle sensor, which is designed as a Hall effect sensor.

The Hall effect sensor, which detects the passage of the finger thread guide through the center of the thread-passing area, is protected within a plastic housing.

A disadvantage of these proven per se angle sensors, however, that set in the course of time inherent error influences.
For example, the temperature drift or the aging process of the permanent magnets must be calculated for these principle-related fault influences.

Based on the aforementioned prior art, the present invention seeks to develop a method and a device that allows the proper operation of a job of a cheese-producing textile machine over a longer period. In particular, it should be ensured that the measured values of the angle sensor of the thread guide remain highly precise over the entire service life of the device.

This object is achieved by a method as described in claim 1 or by a device according to claim 4.

Advantageous embodiments of the method and the associated device are the subject of the dependent claims.

By means of the method according to the invention, it is reliably prevented that principle-related fault influences, such as, for example, the temperature drift or the aging process of the permanent magnets, can gradually falsify the measured values of the angle sensor over time and thus unnoticed.
In other words, due to a periodic and / or event-related comparison of the measured values supplied by a sensor element with defined positions of the thread guide, error influences are reliably detected and correspondingly taken into account, for example by the workstation computer, whereby the thread guide is first successively determined in two to determine corresponding measured values of the sensor element. defined positions is driven.

In each case, a measured value is generated by the sensor element in these defined positions. The determined measured values are compared in the workstation computer and / or processed to calculate a correction characteristic of the sensor element.
The correction characteristic curve calculated by the workstation calculator characterizes the measured value curve of the electrical voltage that the sensor element generates at this time when the thread guide oscillates between its reversal points.

As explained in claim 2, the workstation computer assigns during the winding process according to the correction characteristic of each voltage generated by the sensor element to the associated position of the thread guide, which is then used to control the thread guide.

In an advantageous embodiment, the determined correction characteristic, as set forth in claim 3, at least until the next adjustment use.
This means that during the next adjustment, the correction characteristic curve is recalculated by the workstation computer based on the measured values then available and, if the calculation results, replaced by a new correction characteristic curve.

According to claim 4, the apparatus for performing the method according to the invention in an advantageous embodiment, acted upon by a single drive Fadenchangiereinrichtung, equipped with a Hall IC element angle sensor and a workstation on. The angle sensor supplies in each case a measured value proportional to the position of a thread guide.
In addition, means are provided which allow positioning of the thread guide in defined positions.

This means that there are exactly defined positions in which an adjustment of the measured values supplied by the angle sensor with known thread guide positions can be made.

As described in claim 5, the workstation computer is designed so that it immediately associates each electrical voltage generated by the Hall IC element of the angle sensor with an associated position of the yarn guide.
In this way, the workstation computer is able to optimally control the thread guide, in particular as regards its reversal points.

In an advantageous embodiment, the thread guide, as described in claim 6, designed as a finger thread guide, the thread-laying lever is positioned by applying two stops each in defined angular positions.
In each case, a measured value generated by the Hall IC element of the angle sensor is detected in these so-called adjustment positions and used in the workstation computer for calculating a correction characteristic curve of the angle sensor.
This correction characteristic curve calculated by the workstation computer characterizes the instantaneous course of the electrical voltage generated by the angle sensor at this time during the traversing of the thread-laying lever.
That is, by the workstation computer are considered in determining the respective angular position of the thread-laying lever error influences resulting from the construction principle of the angle sensor, for example due to a certain aging of the permanent magnets.

As described in claim 7, lies in a preferred embodiment, the coverable by the angle sensor during its calibration range between + 40 ° and -40 °.
That is, this area is slightly larger than the working range of the finger thread guide whose thread-laying lever covers a range between + 37.5 ° and -37.5 ° during the winding operation.
Such a generous dimensioning of the area which can be covered by calibration ensures that the installation tolerances occurring, for example, during assembly of the thread guide drive can be reliably compensated for.
The positioning of defined stops at + 39 ° and -39 ° also makes it possible in a simple way to balance the measured values provided by the angle sensor with known angular positions of the thread-laying lever of the thread guide.
This means that when the thread-laying lever is applied to these stops, it is ensured that the measured values generated by the angle sensor always relate to the same angular position and that deviations in these measured values are due to inherent error influences of the angle sensor, which are taken into account by the workstation computer when calculating a correction characteristic curve.

In a further advantageous embodiment, it is provided that the angle sensor has a resolution of 0.024 ° (claim 8).
Such a high resolution of the angle sensor allows a precise approach of the thread reversal points in the thread switching and thus a homogeneous coil structure.

The invention will be explained in more detail with reference to an embodiment shown in the drawings.

Fig. 1

schematisch eine Arbeitsstelle einer Kreuzspulen herstellenden Textilmaschine, mit einem Spulenantrieb und einem separaten, einzelmotorisch angetriebenen Fadenführer, dessen Antrieb mit einem Winkelsensor ausgestattet ist,

Fig. 2

den auf der Welle des Fadenführerantriebes angeordneten Winkelsensor im Schnitt,

Fig. 3

den Winkelsensor, gemäß Schnitt III - III der Figur 2,

Fig. 4

den Fingerfadenführer in Blickrichtung des Pfeiles X, während eines Abgleichs des Winkelsensors,

Fig. 5

ein Winkelstellung / Ausgangsspannung - Diagramm während eines Abgleichs des Winkelsensors.

It shows:

Fig. 1

1 schematically shows a workstation of a textile machine producing cross-wound bobbins, with a bobbin drive and a separate, single-motor-driven yarn guide, the drive of which is equipped with an angle sensor,

Fig. 2

the arranged on the shaft of the thread guide drive angle sensor in section,

Fig. 3

the angular sensor, according to section III - III of FIG. 2 .

Fig. 4

the finger thread guide in the direction of arrow X, during an adjustment of the angle sensor,

Fig. 5

one angular position / output voltage - diagram during adjustment of the angle sensor.

In FIG. 1 is a schematic side view of the workstation 2 of a cheese-producing textile machine, in the present case of a so-called cross-winding machine 1 shown.
As is known and therefore not explained in more detail, the spinning stations 3 produced on a ring spinning machine are rewound to large-volume cheeses 5 on the work stations 2 of such automatic packages 1.
The cheeses 5 are automatically after their completion, for example by means of a (not shown) working service units on a machine-length cross-bobbin transport device 7 and transported to a machine end side arranged Spulenverladestation or the like.
Such spooling machines 1 generally also have a bobbin and tube transport system 6, in which, on transport plates 11, the spinning cops 3 or empty tubes circulate.
Of the bobbin and tube transport system 6 are in Fig. 1 only the Kopszuführstrecke 24, the reversibly driven storage section 25, one of the leading to the winding units 2 transverse transport sections 26 and the sleeve return path 27 shown.

The individual jobs 2 also have, as known and therefore only hinted, various facilities that ensure the proper operation of such jobs.
One of these devices is, for example, the winding device 4.
The winding device 4 has a coil frame 8 movably mounted about a pivot axis 12.
According to the present embodiment, the cheese 5 is located during the winding process with its surface on a drive drum 9 and is driven by this single-motor actuated drive drum 9 via frictional engagement. The corresponding drive carries the reference number 33.

For traversing the thread 16 during the winding process a Fadenchangiereinrichtung 10 is provided.
Such in the FIG. 1 only schematically indicated Fadenchangiereinrichtung 10 has, for example, a The thread-laying lever 45 traverses, acted upon by an electromechanical drive 14, the thread 16 between the two end faces of the cheese 5. The drive 14 of the thread guide 13 is, for example via a (not shown) console on Spulstellengehäuse 34 of the relevant job 2.
In addition, both the drive 14 of the thread guide 13 and the drive 33 of the drive drum 9 via control lines 15 and 35 are connected to the workstation computer 28.

Like, for example Fig. 2 it can be seen, the drive 14 has a motor shaft 17, on which the finger-like thread laying lever 45 is arranged rotationally fixed.
On the side opposite the yarn guide 13 side of the motor shaft 17 is protected by a removable cap 18, an angle sensor 19 is mounted, the structure will be explained below.

As in Fig. 2 shown, on the housing 39 of the drive 14, on the thread laying lever 45 opposite side, a plastic molded part 31 is fixed, which has both a mounting hole 36 for a sensor carrier 23 and a bearing pin 37 for a stocked with an electronic circuit board 32 38.
The electronic circuit 32 may include, for example, a memory chip and an electronic control device.
At the sensor carrier 23, a Hall-IC element 29 is stationary, which corresponds to a permanent magnet 20, which is rotatably connected via a support ring 21 and a bolt 22 with the motor shaft 17 of the drive 14.

The FIG. 3 shows a rear view of the drive 14, that is, a view of the angle sensor 19 according to section III-III of FIG. 2 ,
As shown, the permanent magnet 20 is formed as a two-pole radially magnetized ring magnet whose poles N, S in the illustrated center position of the yarn guide 13, that is, in the angular position 0 °, with respect to the stationary arranged Hall IC element 29 are arranged orthogonal. That is, when the yarn guide 13 assumes an angular position 0 °, the poles N, S of the magnetic ring 20 are aligned at right angles to the Hall IC element.

The Fig. 4 shows a view of the Fadenchangiereinrichtung 10 in accordance with the direction of the arrow X of Fig. 1 during an adjustment of the angle sensor 19.
As shown, in the front plate 44 of the thread guide drive 14 in defined holes arranged stops 40 and 41, each defining a predetermined, exact angular position of the thread-laying lever 45. The stops 40, 41 are preferably positioned so that the fitting during adjustment at the stop 40 thread-laying lever 45 has exactly an angular position of -39 °, while the angular position of the thread-laying lever 45 at the stop 41 is exactly + 39 °.
The electrical voltage V initiated by the Hall IC element 29 when the thread-laying lever 45 abuts against the stop 40 or 41 is processed in the electronic circuit 32 of the angle sensor 19 and via a data and control line 15 to the workstation computer 28 forwarded therefrom, if necessary, calculates a correction characteristic curve, by means of which each measured value can be assigned to a specific angular position of the thread-laying lever 45.

In Fig. 5 characteristic curves 42, 43 are shown on the basis of a coordinate system which indicate the electrical voltage profile generated by the programmable Hall IC element 29 and dependent on the angular positions of the thread-laying lever 45 and thus on the angular positions of the permanent magnet 20.
On the abscissa of the coordinate system while the area covered by the thread-laying lever 45 during the Fadenchangierung area is shown in degrees, while the ordinate of the coordinate system shows the voltage generated by the Hall-IC element 29 in volts.
That is, the voltage V which generates the Hall IC element 29 from the magnetic flux of the permanent magnets 20, their angular position and a device constants.

With 43 while a characteristic curve for the voltage waveform of the angle sensor 19 is characterized as it had resulted after the calibration of the angle sensor 19 at the beginning of its use.
In the exemplary embodiment is according to characteristic curve 43 at an angular position of the thread-laying lever 45 of -39 ° at the angle sensor 19, for example, a voltage of 0.71 V at. At an angular position of the thread-laying lever 45 of + 39 °, the corresponding voltage at the angle sensor 19 is 4.83 V. As indicated by the characteristic 43, the voltage curve in the covered by the thread-laying lever 45 trailing range between -39 ° and + 39 ° is largely linear.

In the middle position 0 ° of the thread-laying lever 45, the angle sensor 19 consequently produces a voltage of, for example, 2.76 volts.

The characteristic curve 42 shows the voltage curve determined during a later adjustment of the angle sensor 19.
In the exemplary embodiment, the electrical voltage generated by the angle sensor 19 in this adjustment at an angular position of the thread-laying lever 45 of -39 ° is 0.56 V.
At an angular position of the thread-laying lever 45 of + 39 ° 4.47 V are generated.
Since the characteristic 42 has a largely linear course, it results for the middle position 0 ° of the thread-laying lever 45 at the angle sensor 19, a voltage of for example 2.48 volts.

With the present angle sensor 19, for example, a resolution of 0.024 ° can be realized.

Before starting the thread guide drive 14 in the workplace 2, the angle sensor 19 must first be calibrated.
In this calibration, the angle sensor 19 on the fully assembled drive 14 can be followed by various methods that in the post-published DE 103 54 587 are described in relative detail.

In one of these calibration methods, for example, the magnetic characteristic of the permanent magnet 20 of the Angle sensor 19 measured by means of defined angular positions of the thread-laying lever 45 of the thread guide 13.
In other words, the thread-laying lever 45 is successively positioned in defined angular positions by means of a simple mechanical device, for example two stops 40, 41, thereby detecting the electrical voltage generated in the Hall IC element 29 due to the magnetic flux of the permanent magnet 20.
The workstation computer 28 of the relevant winding unit 2 then calculates a first characteristic curve for the angle sensor 19 on the basis of the known positions of the thread-laying lever 45 and the detected measured values of the angle sensor. This first characteristic curve is in the coordinate system of FIG Fig. 5 marked with the reference number 43.
As in Fig. 5 indicated, each point of the characteristic 43 is associated with a certain angular position of the thread-laying lever 45 and a corresponding measured value of the angle sensor 19.
In a middle position of the thread-laying lever 45, that is, at an angular position of 0 °, the associated measured value of the angle sensor is, for example, 2.76 V.

The balancing method according to the invention runs as follows:

Since the characteristic of the angle sensor 19 changes in principle over time, for example due to the aging of the permanent magnets 20 of the angle sensor 19, by temperature drift or the like, corresponds to a reading of, for example, 2.76 V only a certain time exactly an angular position of 0 ° the thread-laying lever 45.
In order to be able to ensure exact measured values of the angle sensor 19 over a longer period of time, the angle sensor 19 is therefore adjusted from time to time.

In this second calibration method, the magnetic characteristic of the permanent magnet 20 is re-measured.
This can be done in an external calibration device or in the workplace.
The determined correction values are then stored either in the workstation computer 28 of the winding unit or in an additional memory chip (not shown) of the electronic circuit 32 of the angle sensor 19.

That is to say, the thread-laying lever 45 is driven, for example, again one after the other, to the defined stops 40, 41, and the measured values generated by the angle sensor 19 are detected in these angular positions.
From these measured values, the workstation computer 28 then calculates a correction characteristic 42, as shown in FIG Fig. 5 is shown.
The correction characteristic 42 also has a linear course.
Furthermore, each point of the correction characteristic 42 is also assigned a specific angular position of the thread-laying lever 45 and an associated measured value of the angle sensor 19 in volts.
At the in Fig. 5 Correction characteristic line 42 shown as an exemplary embodiment corresponds to a measured value of, for example, 0.56 V of an angular position of the thread-laying lever 45 of -39 °. In the center position 0 ° of the thread-laying lever 45, a measured value of 2.48 V is present at the angle sensor 19, while the measured value of the angle sensor 19 is 4.47 V at an angular position of + 39 ° of the thread-laying lever 45.

The correction characteristic 42 of the angle sensor 19 remains relevant until the next adjustment and is then optionally replaced by a new correction characteristic, which is also determined by a corresponding adjustment.

Claims (8)

1. Method for operating a workstation (2) of a textile machine (1) producing cross-wound bobbins, comprising a creel (8) for holding a rotatable wind-on bobbin (5), a thread traversing mechanism (10), which is driven by a single motor, and a sensor element (19) which can be calibrated and supplies a measured value that is proportional to the position of the thread guide (13), whereby a proper operating mode of the sensor element (19) is ensured in that an adjustment takes place between measured values supplied by the sensor element (19) and defined positions of the thread guide (13), at predeterminable time intervals and/or in relation to events, characterised in that to determine the measured values of the sensor element (19) during a winding interruption, the thread guide (13) is moved successively into determined, defined positions, in that in these positions, a respective measured value of the sensor element (19) is detected and in that the detected measured values are processed in the workstation computer (28) to calculate a characteristic correction curve (43) of the sensor element (19).
2. Method according to claim 1, characterised in that during the winding process, the workstation computer (28), according to the characteristic correction curve (43), allocates the associated position of the thread guide (13) to a voltage (V) generated by the sensor element (19), which position is then used to control the thread guide (13).
3. Method according to claim 2, characterised in that the determined characteristic correction curve (43) is then used until the next adjustment of the sensor element (19).
4. Device with a thread traversing mechanism driven by a single motor for carrying out the method according to claim 1, characterised in that the single drive of the thread traversing mechanism has a calibrated angle sensor which is equipped with a Hall IC element and is connected to a workstation computer, and supplies a measured value proportional to the position of the thread guide, and in that provided in the region of the thread traversing mechanism (10) are means (40, 41), which allow a positioning of the thread guide (13) in defined, reproducible positions.
5. Device according to claim 4, characterised in that the workstation computer (28) is configured, such that it links each voltage (V) generated by the Hall IC element (29) of the angle sensor (19) with an associated position of the thread guide (13).
6. Device according to claim 4, characterised in that the thread traversing device (10) is configured as a finger thread guide (13), the thread placing lever (45) of which can be positioned in defined angle positions by disposing on stops (40, 41).
7. Device according to claim 6, characterised in that the angle range which can be covered by the angle sensor (19) by calibration is between +40° and -40°, in that the working range of the thread placing lever (45) is between +37.5° and -37.5°, and in that the stops (40, 41), on which the thread placing lever (45) is positioned for adjustment, are arranged in each case at + 39° and at -39°.
8. Device according to claim 4, characterised in that the angle sensor (19) has a resolution of 0.024°.

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