EP0519991B1 - Process for warping threads and warping machine - Google Patents

Abstract

In a process for warping threads, the thickness of a single lap and that of a few laps are measured with high accuracy while applying a defined surface pressure in the measurement region. From the result a corrected temporary feed signal is first produced, followed by a corrected final feed signal.

Description

The invention relates to a method for warping according to the preamble of claim 1 and a cone warping machine according to the preamble of claim 8.

The method for warping threads on a warping drum of a cone warping machine is known from DE-OS 37 02 293. In this method, a warping mechanism is shifted depending on the increasing winding thickness relative to the warping drum, by scanning the winding circumference by a sensing element when the warping drum is at a standstill while the first band is being warmed with a given warping slide feed, and thereby adjusting its path during a measuring winding phase depending on the number of Revolutions of the warping drum is measured. Then, when the remainder of the first warping belt is warmed and after the measuring roll has been copied when the subsequent belts are warmed, the advance of the warping carriage when the rest of the subsequent belts are warmed is corrected in accordance with the measured adjustment path. First When the first band is warmed, a basic winding is warmed with a predetermined warping slide feed and the winding circumference is scanned by the feeler, the adjustment path of which is measured as a function of the number of revolutions. The feeler element is then adjusted in accordance with the adjustment path measured when the base winding is warmed and a corrected feed provided for the rest of the first band is determined from the difference between the measured adjustment path in the measurement winding and the measured adjustment path in the base winding. All other warping belts are warmed like the first belt with regard to the base and measuring roll with the specified feed and the remaining roll with the corrected warping carriage feed.

The disadvantage of the known method is that a stepped winding is created due to the three-part structure of the first warping belt. A further disadvantage is that although the corrected feed value is already known, the subsequent windings must be wound in the same way, that is to say with the base and measuring windings with the initially specified warping carriage feed, in order to ensure that all subsequent warping belts have the same structure.

A laser light distance measurement is known in principle from DE-ZS der elektroniker (3/1989, pp.32-34 and 7/1987, pp.78.-83).

The invention has for its object to provide a method and an apparatus for warping threads on a warping drum, in which or in which a step winding structure is avoided and in which subsequent warp belts can be wound with the corrected warping feed once determined.

• daß in einem ersten Schritt die Auftragsdicken-Meßeinrichtung in einer bestimmten Drehstellungsposition der Schärtrommel ohne Wickelauflage kalibriert wird, und anschließend die Schärtrommel um eine Umdrehung gedreht wird,
• daß in einem zweiten Schritt die Auftragsdicke der ersten mit der vorläufigen Vorschubgeschwindigkeit gewickelten Wickellage unter Aufbringung einer definierten Flächenpressung im Meßbereich in der gleichen Drehstellungsposition der Schärtrommel wie zuvor gemessen wird und in Abhängigkeit vom Auftragsmeßsignal und Umdrehungssignal ein korrigiertes vorläufiges Vorschubsignal erzeugt wird,
• daß in einem dritten Schritt einige wenige Wickellagen aufgeschärt werden und anschließend die Auftragsdicke mit einer zweiten definierten, im Vergleich zur ersten niedrigeren Flächenpressung im Meßbereich in der gleichen Drehstellungsposition der Schärtrommel wie zuvor gemessen wird und vom Rechner in Abhängigkeit vom zweiten Auftragsmeßsignal und vom Umdrehungszählsignal ein korrigiertes endgültiges Vorschubsignal erzeugt wird, und
• daß das endgültige Vorschubsignal allen nachfolgenden Wickelvorgängen zugrunde gelegt wird.

To achieve this object, the invention provides

• that in a first step the application thickness measuring device is calibrated in a specific rotational position of the warping drum without a winding support, and then the warping drum is rotated by one turn,
• that in a second step the thickness of the first winding layer wound with the preliminary feed speed is measured with the application of a defined surface pressure in the measuring range in the same rotary position of the warping drum as before, and a corrected preliminary feed signal is generated as a function of the order measurement signal and rotation signal,
• that in a third step a few winding layers are heated and then the application thickness is measured with a second defined, compared to the first lower surface pressure in the measuring range in the same rotary position of the warping drum as before and a corrected by the computer depending on the second order measurement signal and the revolution count signal final feed signal is generated, and
• that the final feed signal is used as a basis for all subsequent winding processes.

• bei der eine Anpreßvorrichtung der Auftragsdickenmeßvorrichtung je nach der Anzahl der Umdrehungen der Schärtrommel mit unterschiedlicher Flächenpressung auf das Schärband drückt und
• eine Laserlicht-Entfernungsmeßeinrichtung über die Verlagerung der Anpreßvorrichtung die Auftragsdicke mißt.

According to the invention, a cone warping machine is also provided,

• in which a pressing device of the application thickness measuring device presses on the warping belt with different surface pressure depending on the number of revolutions of the warping drum and
• a laser light distance measuring device measures the thickness of the application by moving the pressing device.

According to the invention, in a first step the application thickness measuring device without a winding support is calibrated in a specific rotational position of the warping drum by measuring the position of the warping drum without a winding support and then rotating the warping drum by exactly one revolution with a predetermined feed for the warping belt. The specific rotary position of the warping drum must therefore be set in order to achieve greater accuracy when measuring the application thickness of the warping roll, in which deviations in the diameter of the warping drum are compensated for. Due to the compensation of the warping-related measurement deviations and the compression of the first winding layer before the measurement, a corrected preliminary feed signal can be generated in the second step with high accuracy and reproducibility when measuring the thickness of the first winding layer, so that practically from the first layer already is sharpened at a feed rate very close to the final feed. When measuring the application thickness, the first layer is compressed with a first relatively high surface pressure before measuring the application thickness. In the third step, a few winding layers are prepared with the corrected feed, which are measured with regard to their application thickness when the warping drum is stopped again. A lower surface pressure is applied in the measuring area compared to the second step. The rotary position of the warping drum is the same as the first and second step, so that machine-related errors are compensated. A corrected final feed signal is then generated from the resulting order thickness per number of revolutions, which is used as a basis for all subsequent winding processes. An important advantage of the invention is that after a single winding position a feed signal which is very close to the final feed signal for the warping is generated, and that the final feed signal is determined after only a few winding positions. As a result, after a few layers of the first warping belt, a warping roll can be warmed up with constant conditions. All subsequent warping belts are warmed up under the same conditions without producing a difference in the winding structure between the first and all further warping belts.

In the third step, a maximum of five layers are prepared. In this way it is ensured that only an extremely small number of layers are sharpened with the provisionally corrected feed signal. Since the difference between the temporarily corrected feed signal and the finally corrected feed signal is small, the influence on the winding structure is negligible.

It is preferably provided that the surface pressure value for the third step is set depending on the number of winding layers, the material properties of the threads and / or the creel thread tension. The number of winding layers results from the revolution count signal. The creel thread tension can be adjusted accordingly Sensors are measured and passed on to the controller. With regard to the material properties of the threads, it is possible to enter them in the form of factors in a computer of the control or to enter factors in advance in the computer depending on the yarn count and quality, so that only the material parameters have to be entered.

The exposed threads can be compressed in the measuring range of the application thickness measurement in the entire bandwidth of the warping belt. In this way, there is a good mean value for the application thickness of the warping belt.

The application thickness measurement is preferably carried out indirectly as a laser light distance measurement. According to a preferred exemplary embodiment, the laser light is directed onto the back of a plate which generates the surface pressure. Such an application thickness measurement can be carried out with a resolution of 1/1000 mm.

The plate can be pressed against the warping drum in the first step (measurement without changing table) with the same force as in the second step (measurement of the first layer). In this way, possible deformations of the plate due to the contact pressure can be compensated and a higher accuracy can be achieved when measuring the thickness of the coating.

In the following an embodiment of the invention will be explained with reference to the drawings.

Fig. 1

eine Konusschärmaschine im Aufriß und im Schema,

Fig. 2

den Bandaufbau bei einer Konusschärmaschine und die

Figuren 3a, 3b, 3c

den Meßvorgang zur Bestimmung der Auftragsdicke.

Show it:

Fig. 1

a conical warping machine in elevation and in the diagram,

Fig. 2

the belt structure in a cone warping machine and the

Figures 3a, 3b, 3c

the measuring process to determine the thickness of the coating.

The cone warping machine 1 has a warping drum 2 with a cylindrical part 3 and a cone part 4. The warping drum 2 is supported in bearings 6 by a base frame 7. The base frame 7 is designed as a carriage and can be moved back and forth on rails 9 by means of the running wheels 8. A motor 11 with a rotary pulse generator drives the shaft 5 and thus the warping drum 2 by means of a transmission element 12 and a belt wheel 13, a brake 14 being provided for a brake disk 15. With 16 the traction motor is designated. Another motor 17 drives a threaded spindle 18, from which a support 20 can be pushed back and forth along the warping drum 2 by means of a spindle nut.

The support 20 has a slide 21 which can be pushed back and forth on guides along the warping drum 2 by means of the spindle 18. Another carriage is attached to the carriage 21 in a height-adjustable manner. The further carriage carries the drive mechanism for the movement of a sliding rivet 25 transversely to the warping drum 2 and for the height adjustment of the further carriage with the other parts attached to it.

The sliding rivet 25 sits on a spindle which is driven by its own motor.

Fig. 2 shows the winding construction of the first warping band in a cone part 4 with a cone angle α to the drum axis of 15 °.

berechnet.With h is the order amount per drum revolution, so that the feed s _v per drum revolution $${\text{s}}_{\text{v}}\text{= h / tan α}$$

calculated.

FIGS. 3a to 3c explain the method steps for automatically determining the feed rate applicable for the special application with the aid of an application thickness measuring device 35, essentially consisting of a pressing device 19 and a laser light distance measuring device 22.

In a first step, the pressing device 19, for example a stamp plate, is pressed with a defined force against the cylindrical part 3 of the warping drum 2 with the aid of a pneumatic piston-cylinder unit 24. When the full contact pressure is present, the laser light distance measuring device 22 is activated and this position of the contact pressure device 19 is calibrated in the form of a base value for the application thickness. The laser beam 26 of the laser light distance measuring device 22 is directed towards the rear of the pressing device 19, the surface of which is parallel runs to the drum axis of the warping drum 2. The distance measurement value is reduced by the constant thickness or thickness of the stamp plate. Since all measured values are reduced by the same amount, the deviation is automatically compensated.

The pressing device 19 consisting of the stamp plate is pressed orthogonally to the axis of the warping drum 2 against the outer surface of the cylindrical part 3 of the warping drum 2.

In the first measuring process, in which no warping belt 10 has yet been hardened, the pressing device 19 is pressed on with a defined pressing pressure and the laser light distance measuring device 22 is activated at the same time. The warping drum 2 is in a certain rotational position, which is set again exactly reproducibly for each measurement. The laser light distance measuring device 22 is calibrated during this first measurement, so that a difference value for the application thickness of the winding layers can be measured in the subsequent measurements.

After the calibration, the warping drum 2 is brought back exactly one revolution at a predetermined feed rate for the warping reed 25 into the same rotational position in which a second measurement according to FIG. 3b takes place. For this purpose, the pressing device 19 is pressed against the first winding layer with a pressing pressure, which is set to a predetermined value taking into account the material properties, the warping bandwidth, the fineness of the threads, etc. To create the same measurement conditions and the accuracy of the measurement To increase, it is recommended to use this contact pressure for the first measurement to calibrate the laser light distance measuring device 22.

After the application thickness of the first winding position of the warping belt 10 has been determined by forming the difference with the measured value determined in the first step, the computer of the controller 23 can calculate a first preliminary feed from the formula s _v h / tan α, where s _{v is} the feed in mm / drum revolution, h is the application height per drum revolution in mm and α is the cone angle to the warping drum axis.

This first preliminary feed value already represents a very good approximation of the final feed value to be determined, so that the warping takes place practically from the first winding position with the required feed value.

As can be seen from FIG. 3c, after the application thickness of the first winding layer has been measured, a few, at most up to about five winding layers are fanned out and then another measurement is carried out in the same rotary position of the warping drum 2 as before. In this case, influences on the thickness of the application are taken into account which result from the fact that subsequent winding layers can fit into the gaps between the threads of the previous winding layer. The pressing device 19 is delivered with a lower pressing force in comparison to the previous measurement in order to avoid excessive compression of the winding layers. This second contact pressure can also be automatically by the computer depending on the thread material, the fineness of the threads and the warping bandwidth can be specified from a map stored in the computer. The measurement of the order thickness of several winding layers enables the correction of the preliminarily corrected feed so that a final feed value is now determined.

All subsequent warping belts are warmed with this final feed from the start without having to measure the thickness again. Compared to the first warping belt, there is no different winding structure for the subsequent warping belts, since the final feed has already been set after a few winding layers.

Claims (9)

1. A method of warping threads onto a warping drum (2) of a cone warping machine (1), wherein, after setting a preliminary feed velocity for a warping comb (25), the thickness of the add-on of the warped lap is scanned at least twice, and wherein, after the second scanning, a corrected feed velocity is set with which the warped lap is warped on completely, said corrected feed velocity depending on the number of rotations of said warping drum (2) and on the resulting thickness of the add-on,
   characterized in that

   - in a first step, the means for measuring the thickness of the add-on is calibrated in a predetermined rotational position of the warping drum (2) having no lap thereon, and that, subsequently, the warping drum (2) is rotated for one rotation,

   - in a second step, the thickness in which the first lap layer, wound at the preliminary feed velocity, is applied, is measured in the same rotational position of the warping drum (2) as before, a defined surface pressure being exerted in the measuring area, and a corrected preliminary feed signal is generated in dependence on the thickness measuring signal and the rotation signal,

   - in a third step, a few layers are warped and, subsequently, the applied thickness is measured in the same rotational position of the warping drum (2) as before, using a second defined surface pressure in the measuring area, which is lower than the first surface pressure, and a corrected final feed signal is generated by a computer in dependece on the second thickness measuring signal and the rotation count signal, and

   - the final feed signal is used as a basis for all following winding operations.
2. The method of claim 1, characterized in that a maximum of five layers is warped in said third step.
3. The method of claim 1 or 2, characterized in that the surface pressure value of said third step is set in dependence on the number of lap layers, the material properties of the threads and/or the thread tension in the creel.
4. The method of one of claims 1 to 3, characterized in that, in the measuring area, the warped threads are compressed over the entire width of the band (10) of warp threads.
5. The method of one of claims 1 to 4, characterized in that the measuring of the add-on is performed indirectly as laser light distance measuring.
6. The method of claim 5, characterized in that said laser light is directed onto the rear side of a die plate (19) generating said surface pressure.
7. The method of claim 6, characterized in that, in said first step, said die plate (19) is pressed against said warping drum (2) with the same force as in said second step.
8. A cone warping machine with a warping drum (2) and a warping comb (15) displaceable on a warping carriage (21) parallel to said warping drum (2), through which warping comb bands (10) of warp threads may be warped onto said warping drum (10), and with a device (35) for measuring the thickness of the add-on, as well as a device for detecting the number of rotations of said warping drum, and with a control (23) for generating a feed signal for said warping comb (25) in dependence on a signal indicative of the add-on thickness and on a rotation count signal,
   characterized in that

   - after one or a plurality of rotations of said warping drum (2), a pressing device (19) of said add-on thickness measuring device (35) acts on said reeled band (10) of warp threads with different surface pressures according to the respective number of rotations of said warping drum (2), and

   - a laser light distance measuring device (22) measures the thickness of the add-on by the displacement of said pressing device (19), said measure always being taken in the same rotational position, and

   - said control (23) generates a corrected feed signal after each measuring of the add-on.
9. The warping machine of claim 8, characterized in that said control sets a feed signal for said pressing device (19) depending on the number of lap layers, the material properties of the threads and/or tension of the threads in the creel.

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