EP1342688B1 - Method and apparatus for winding a thread on a cross-winding machine - Google Patents

Description

The present application relates to a method for winding a thread in so-called wild winding on a cheese winding, for example, an open-end spinning machine, according to the preamble of claim 1. When winding threads on cheeses known to occur the problem that it comes to so-called image windings , which represent disturbances in the structure of a cross-wound bobbin. These occur in particular always when per double stroke of the thread guide of the cheese winding complete Spulenumdrehungen take place. The image windings are characterized in that the deposited thread of a preceding thread layer is wound by the subsequent layer of the winding.

Picture windings mean considerable disturbances in the construction of a coil, which must be avoided as far as possible, since they can lead to disturbances in the further processing process, in particular during the unwinding of the thread from the reel. When unwinding, it can lead to tees of several thread layers of the coil, which can then lead to production interruptions in the subsequent process.

Numerous methods and devices are known in the art, which are intended to overcome these problems in the coil structure. Thus, from DE 25 34 239 a method for image disturbance on a cross-wound bobbin is known, wherein synchronously and depending on the movement of the Yarn guide the speed of the winding roller is chosen so that the quotient of peripheral speed of the cheese and the cosine of the half crosshairs angle is constant. For the image disorder itself two different speeds are provided for driving the yarn guide. It is provided, for example, with the help of an additional device, the speed of the rotating drive of the thread guide tap and control the drive of the cheese or the winding roller from the determined value. In another embodiment, a complex manual or planetary gear is used.

DE 43 37 891 A1 describes a method for winding threads in which to avoid image windings, a non-periodic change in the traversing speed, with switching between maximum and minimum values of the traversing speed and thereby approximately a proportional dependence of the change in the peripheral speed of Winding roller is specified by the change in the traversing speed.

Also DE 42 25 242 A1 deals with the problem of a method for operating a winder show with the traversing or traversing pattern can be varied according to the intended use of a package and the control of a Reibwalzenantriebs and a traversing drive is feasible. For this purpose, it proposes a winding method for a automatic winder, which is provided with a control device by which independently of each other, the rotational speed of a motor for a friction roller, which is in contact with a package reel and a traversing device can be controlled. In this case, the winding method according to the invention for the automatic winder allows the selection of several Bewicklungsmustern. The proposed solution that the motor of the traversing device is controlled according to the winding speed of the coil, however, has the disadvantage that in the determination of the winding speed of the coil, the measurement to be made may be subject to errors. About that In addition, sometimes very complex calculation methods are required to achieve the desired results.

From DE 196 28 402 it is known to change the traversing speed of the yarn guide to avoid image windings and adjust the peripheral speed of the winding roller accordingly in the reverse manner, one of the two speeds is used as a guide and the other as a result. It can be used for driving the winding roller and the thread guide synchronous motors.

The solutions of the prior art either require a high mechanical or control engineering effort or do not lead to a satisfactory result in the image disturbance. For the sake of simplicity, DE 4337891 A1 proposes to provide approximately a proportional dependence of the change in peripheral speed on the change in the traversing speed. But this leads to the fact that Quotient of peripheral speed of the cheese and the cosine of the half-thread crossing angle does not remain constant. This has the disadvantages explained in DE 2534239 A1 with regard to the thread tension during winding, which can not be kept constant.

Object of the present invention is to avoid the disadvantages of the prior art and to propose a method and apparatus, with which the construction of a coil can be significantly improved, and image windings are reliably avoided, the control engineering effort is kept small and the thread tension during the Winding the thread can be kept constant even with changing crosshairs.

The present object is achieved by the method of the invention according to the features of claim 1 and by means of a device according to claim 12. According to the inventive method is advantageously achieved that the speed of the motors of the drives can be determined via a signal representing the crosshairs angle. It can thus be advantageously controlled with a signal, both the speed of the thread guide drive and the winding roller. It is therefore not necessary to detect the speed of the one motor and to determine the speed of the other drive from this detected signal. Rather, it is sufficient if a control device is present on a winder or winding unit, which generates a signal from the desired parameters, with the help of which the drives control the motors of winding roller and yarn guide as desired. Advantageously, it is thus achieved that both the increase in the rotational speed of the drive of the thread guide and the associated simultaneous reduction in the rotational speed of the drive of the spool roller can be controlled with the signal.

As a result, there can be no calculation errors that can occur when generating a dependent signal. In particularly advantageous Further development of the invention, the drives are already delivered the value of half the crosshair angle, since the drives anyway need the value of half the crosshair angle in the required determination of the speed of the motors.

Advantageously, the value of the cross-hair angle or the half cross-hair angle is set by a control unit for image disturbance, which in turn can be controlled from the outside via an operator set by the machine control, so that the required parameters for the thread can be implemented by the control unit. In a particularly advantageous embodiment of the method according to the invention, the motors are designed as frequency-controlled motors, because thereby a safe and fast reaching the required speed can be achieved. Particularly favorable is the method in which the drives or their control units can control the speed of the motors with the aid of an angle function.

According to the invention, it is thus advantageously possible in a simple manner to keep constant the quotient of peripheral speed of the cross-wound bobbin and cosine of the half cross-hair angle. It is thereby completely held the thread tension constant.

The device according to the invention achieves a winding of a thread, without the bobbin assembly is disturbed, and without the thread is unintentionally exposed to a higher or lower voltage. It even remains guaranteed that the thread can always be wound up with constant tension on the spool despite changing the crosshair angle. Further advantages of the invention are shown in the subclaims and in the descriptions of the associated figures.

Figur 1

eine schematische Darstellung einer Vorrichtung zum Aufwinden eines Fadens gemäß der Erfindung,

Figur 2

eine graphische Darstellung zur Verdeutlichung des Zusammenhangs von Fadenkreuzungswinkel und Geschwindigkeit von Wickelwalze und Fadenführer.

Show it:

FIG. 1

a schematic representation of a device for winding a thread according to the invention,

FIG. 2

a graphical representation to illustrate the relationship between crosshairs and speed of winding roller and thread guide.

Figure 1 shows the essential elements of a device for winding a thread, shown schematically. For the winding of the thread this is withdrawn in a known manner, for example, at a constant speed of a cop or from a spinning device, such as an open-end spinning device, and transferred to a winding device 10, where the thread is inserted into a yarn guide 4, by a reciprocating motion guides the yarn along a winding roller 5. On the winding roller 5 is a coil 51 which is driven by friction of the winding roller 5, practically with the same peripheral speed as the winding roller 5 itself. The device 1 for winding up a thread may be formed as a single winding unit or, as in the embodiment of FIG. 1, with many adjacent devices arranged on a machine. In the latter case, the winding rollers 51 are connected to each other via a shaft 53, wherein the drive via the motor 36 which drives the shaft 53 and thus all the winding rollers 5 as well.

Each winding roller 5 is associated with a yarn guide 4, wherein the yarn guide 4 are arranged on a common, reciprocal traversing rod 52. The traversing rod 52 is driven via a traversing gear (not shown) with a parallel to the shaft 53 traversing traversing. To wind up the thread (not shown) this is in the yarn guide 4 is inserted and is guided by this in the vicinity of the gap between the spool 51 and the winding roller 5. He is clamped between the spool 51 and the winding roller 5 and placed crosswise on the spool 5 due to the reciprocating movement of the yarn guide 4.

The yarn produced, for example, by a spinning station of an open-end spinning device is withdrawn from the spinning rotor by a so-called take-off roll, the peripheral speed of the take-off roll corresponding to the so-called delivery speed of the thread. The speed at which the thread is wound on the spool 51 is different from the speed of delivery, with the thread usually being wound on the spool at a faster speed than the speed of delivery. This is referred to as the so-called tension warp, which in practice means a warping of the elastic thread during winding onto the spool. With the help of the Anspannverzuges the hardness of the coil 51 is determined. The speed of the wound thread is then referred to as the so-called winding speed (V _L * V _A ), which thus results from the delivery speed and the so-called tension distortion.

For the quality of the coil produced by the device 1 for winding up a thread, it is an important prerequisite to keep constant the winding speed and thus the tension within the wound thread. The winding speed is composed at the winding device from the superposition of two other speeds, namely from the speed of the yarn guide (V _FF ) and the peripheral speed (V _W ) of the winding roller. 5

$$\mathrm{Geschwindigkeit\hspace{1em}des\hspace{1em}Fadenf}\ddot{\mathrm{u}}\mathrm{hrers\hspace{1em}}\left({\mathrm{V}}_{\mathrm{FF}}\right)=\mathrm{Wickelgeschwindigkeit\hspace{1em}}({\mathrm{V}}_{\mathrm{L}}*{\mathrm{V}}_{\mathrm{A}})*\mathrm{Sinus\hspace{1em}}\left(\mathrm{½\hspace{1em}\alpha }\right)\mathrm{.}$$

Since, therefore, the delivery speed and the tensioning delay are fixed for a particular thread produced, for example, on a spinning machine, this results in a simple mathematical relationship the determination of the peripheral speed (V _W ) of the winding roller 5 as well as the speed (V _FF ) of the thread guide. These relationships are as follows: $$\mathrm{Peripheral\; speed\; winding\; roller}\left({\mathrm{V}}_{\mathrm{W}}\right)=\mathrm{winding\; speed}({\mathrm{V}}_{\mathrm{L}}*{\mathrm{V}}_{\mathrm{A}})*\mathrm{cosine}\left(\mathrm{½\; \alpha }\right)$$

$$\mathrm{Speed\; of\; the\; thread}\ddot{\mathrm{u}}\mathrm{hrers}\left({\mathrm{V}}_{\mathrm{FF}}\right)=\mathrm{winding\; speed}({\mathrm{V}}_{\mathrm{L}}*{\mathrm{V}}_{\mathrm{A}})*\mathrm{Sine}\left(\mathrm{½\; \alpha }\right)\mathrm{,}$$

To prevent image windings is thus due to the above-indicated relationship, only the possibility of changing the yarn guide speed and thus the peripheral speed of the winding roller when winding up. This has long been shown in the prior art (DE 25 34 239 A1).

The device 1 for winding a yarn to a cross-wound bobbin (51) according to the present invention has a control device 2, which provides the required parameters to the drive 34 for the winding rollers 5 and the drive 35 for the yarn guide 4. These are the delivery speed (V _L ) of the thread, the desired tension distortion (V _A ), the desired crosshair angle (α) and the parameters for the image disturbance. Since the image disturbance is due to a change in the crosshair angle, the information required for it is correspondingly a value corresponding to the change of the crosshair angle and the time course thereof. Since the other parameters, in particular the delivery speed, remain unchanged for the bobbin formation and, for the presentation of the present invention, essentially only the observation of the crosshair angle and its desired change is of interest for the image disturbance and the consequent change in the peripheral speed of the winding roller.

The control devices 6 for driving the winding rollers 5 and the drives 35 for the yarn guide 4 are designed as frequency converters that control the motors 36, which are designed as synchronous motors. The frequency converter of the control units 6 are equipped in a known manner with a computer unit, with the help of which they convert the specifications for the desired speeds to a corresponding frequency. The control units 6 receive the required specifications for delivery speed, tensioning distortion and the crosshair angle α. The control units 6 can receive the required information from the control device 2, or via other elements, for example via speed sensors, which tap the speeds of certain higher-level drives and map, for example, the delivery speed, from which the control units 6 then determine the corresponding speeds for the motors 36 can.

In addition, the control units 6 receive, for the purpose of image disturbance from the control device 2, a signal which is suitable for conveying to the control units 6 information about which crosshair angle is to be used for calculating the rotational speed of the motor 36 controlled by the respective control unit 6. That that is, the signal may consist of information about the crosshair angle itself, or, for example, also in an information about a desired change in a crosshair angle and particularly advantageously also in a time sequence of the desired change in the crosshair angle.

From this information, the control unit 6 in conjunction with the other required information, which determine the speed of the motor 6 associated with the control unit 6 at the now prescribed crosshair angle. A control unit 6 also requires it the information about which motor controls them, ie the motor for the thread guide drive or the motor for the winding roller drive.

The great advantage of the method according to the invention is that the control by specifying the crossing angle of the thread is particularly suitable to control frequency converter. This ensures that a fast and reliable driving of the motors 36 can take place without additional measures. This is achieved both by specifying the thread pitch angle and by specifying a change in the crossing angle. Complex methods for calculating the required engine speeds for the winding roller from the speed of the thread guide drive are superfluous and are no longer necessary.

The specification of the crosshair angle, or the specification of the change in the crosshairs angle, is sufficient to implement with the aid of the implemented calculation of the angular functions within the control unit 6 quickly and precisely the coordinated speeds of winding roller and yarn guide. If necessary, it is also possible, for example, only the control unit for the drive 35 of the thread guide 4 to connect directly to the control device 2, if it is ensured that the control unit 6 for the drive 35 of the thread guide the information about the crosshairs angle to the drive 34 of the winding roller 5 forwards. This is indicated in Figure 1, that the data connection 7 between the control device 2 and the control unit 6 of the drive 34 is shown with a broken line, as well as the then required line 71 between the two control units 6 of drive 34 and drive 35th

FIG. 2 shows in a graphical diagram the mathematical relationship between the various relevant speeds and the crosshair angle α. As is clear from the diagram, the addition of the peripheral speed (V _W ) of the winding roller 5 and the yarn guide speed (V _FF ) must result in the winding speed (V _L * V _A ). The winding speed (V _L * V _A ) is a constant, so does not change during winding and thus also when disturbing the picture! As can be seen from the illustration, therefore, the circumferential speed (V _W ) of the winding roller must decrease with an increase in the yarn guide speed (V _FF ) so that, as required, the winding speed remains constant. The crosshair angle must then increase accordingly. The crosshair angle α corresponds to the angle between the thread deposited during the outward movement of the thread guide and that of the thread deposited during the movement of the thread. For the mathematical consideration, see Figure 2, only half the crosshair angle (½ α) is interesting.

Claims (15)

1. A method to avoid ribbon winding for the winding of threads to cross wound bobbins with random winding, where the winding speed is predetermined by depending on the feeding velocity, tension draft and crossing angle of the thread, wherein to break the pattern a variation of the thread crossing angle of the wounded thread occurs where the speed of the winding cylinder (5) and the thread guide (4) are changed and the winding cylinder (5) and the thread guide (4) are driven by own drives (34, 35), characterized in that the motion of the thread guide (4) and the winding cylinder (5) takes place by speed of rotation controlling motors (36) of the drives (34, 35), in which the drives (34, 34) are transmitted a signal, representing the value of the appropriate desired thread crossing angle and wherein the drives (34, 35) by means of that one signal accordingly determine the appropriate rotation and control the motors (36) in an appropriate way, so that no design errors can occur which could arise from generating a depending signal.
2. A method according to claim 1, characterized in that the drives (34, 35) for the thread guide (4) and the winding cylinder (5) get transferred the same signal.
3. A method according to claim 1 or 2, characterized in that the signal variation leads to an acceleration of rotation of the thread guide drive (35) and synchronistical to a deceleration of the rotation of the drive (34) of the winding cylinder (5) or vice versa.
4. A method according to one or more of the claims 1 to 3, characterized in that as a control signal the value of the thread crossing angle or of half the thread crossing angle is transferred to the drives (34, 35).
5. A method according to one or more of the claims 1 to 4, characterized in that for pattern breaking, the value of the thread crossing angle is determined by means of a control device (2).
6. A method according to one or more of the claims 1 to 5, characterized in that the value of the thread crossing angle is varied within predetermined limits by the control device (2) or a control unit (6).
7. A method according to claim 5 or 6, characterized in that the control unit (6) is constructed as a part of one or both drives (34, 35).
8. A method according to one or more of the claims 1 to 7, characterized in that the used motor (36) is a frequency controlled motor.
9. A method according to one or more of the claims 1 to 8, characterized in that the signal of the control unit (6) of the drive is converted by an auxiliary trigonometric function into a rotational speed.
10. A method according to one or more of the claims 1 to 9, characterized in that the quotient of the peripheral speed of the cross-wound bobbin and the cosine of half the thread crossing angle is constant.
11. A method according to one or more of the claims 1 to 10, characterized in that the control unit (6) essentially comprises a frequency converter.
12. Device (1) for the winding of a thread to a cross wound bobbin comprising a control device (2) for presetting a thread crossing angle and for varying the thread crossing angle for the pattern breaking of the thread winding, comprising a drive (34) for the thread guide and a drive (35) for the winding cylinder (5), wherein each drive (34, 35) features a speed rotation controlled motor (36) and a control unit (6) for the motor (36), particularly for processing the method according to one or more of the claims 1 to 11, characterized in that the drives (34, 35) associate to the control device (2) for transmitting the signal of the value for the crossing angle and the control unit (6) defines by means of a predetermined thread cross angle the control signals for controlling the rotation speed of the motors (36), in order to avoid design errors, that can occur by generating a depending signal.
13. A device according to claim 12, characterized in that the control unit (6) is connected to the control device (2) or a rotary encoder, in order to appraise the value of the parameter of the acquired basic rotational speed of the motor.
14. A device according to claim 12 or 13, characterized in that the drives (34, 35) are synchronous motors, which are allocated to a frequency converter with a computer unit as a control device (6), detecting the frequency necessary in order to actuate the synchronous motor (36) via the value of the thread crossing angle predetermined by the control unit (2).
15. A device according to one or more of the claims, 12 to 14, characterized in that the motor is a frequency controlled or speed rotation regulated motor.

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