EP0311815B1 - Method and device to even out the yarn tension when rewinding from cops to cross bobbins - Google Patents

Description

The invention relates to a method for equalizing the yarn tension when rewinding a cop onto a package by means of a winding device according to the preamble of claim 1 and a device for carrying out the method according to the preamble of claim 8.

When a bobbin is unwound, the thread tension increases continuously at the same winding speed. The speed which is equivalent to the maximum permissible thread tension is therefore selected as the maximum constant winding speed.

EP-A-0 237 892 discloses a method and a device for rewinding a thread, in which a residual amount of thread is measured by means of a balance or by means of the thread tension. The target thread tension is then changed as a function of this measurement. Thread speed and thread tension are changed by a directly proportional ratio. This device requires constant measurement during the rewinding process in order to achieve the corresponding adjustment of the desired thread tension during the rewinding process.

The invention has for its object to improve the productivity of the individual winding units without significant additional effort.

This object is achieved by the characterizing features of claim 1.

The unwinding time of a full bobbin is already known for the selected winding speed curve. If not, this is determined by an unwinding test. The winding time is related to the amount of yarn. The bobbin time is longest for a full bobbin with the maximum amount of thread. The unwinding of a full bobbin starts at the maximum winding speed and ends at a winding speed that is, for example, only half the start speed. The winding speed curve can be linear, staircase-shaped or curved. The most appropriate curve is selected or determined for the respective yarn. The aim is to keep the winding speed as high as possible without any disadvantageous values of the yarn tension increase being noticeable. In many cases, therefore, a convex course of the winding speed curve is the cheapest in terms of the effectiveness of the automatic winder. This means that the winding speed decreases slowly at first, then more rapidly at the end of the rewinding process. Under certain circumstances, however, the winding speed can also initially decrease more slowly, then more quickly and then again more slowly, or towards the end of the unwinding process, strive for a limit value or become constant. It is most advantageous if the winding speed is inversely proportional to the thread tension curve. By the adapted The winding tension is evened out, whereby the winding density of the cheese and the hairiness of the wound thread is evened out.

On the process side, the invention is advantageously further developed by claims 2 to 7. A device according to the invention for performing the method according to the invention is described in claim 8. This device is advantageously developed by the characterizing features of claims 9 and 10.

Fig. 1

zeigt schematisch die Teilansicht eines Spulautomaten.

Die Fig. 2 und 3

zeigen Spulgeschwindigkeits-Steuerprogramme in graphischer Darstellung.

Fig. 4

zeigt die Schaltungsanordnung einer Garnmengenmeßeinrichtung und einer Steuervorrichtung eines Antriebsmotors zum Antrieb einer Kreuzspule.

Fig. 5

zeigt eine Kurvenscheibe.

The invention is explained and described in more detail with reference to the exemplary embodiments illustrated in the drawings.

Fig. 1

shows schematically the partial view of an automatic winder.

2 and 3

show winding speed control programs in a graphical representation.

Fig. 4

shows the circuit arrangement of a yarn quantity measuring device and a control device of a drive motor for driving a cheese.

Fig. 5

shows a cam.

In Fig. 1, the automatic winder is designated by 1 in total. It has end frames, of which the front end frame 2 is shown. A dash-dotted line 3 indicates that the automatic winder 1 can have further winding units in addition to the winding units 7 to 11 shown. A traverse 4 connects the end frames to each other and carries the winding units.

Some main parts of a winding unit will be explained in more detail using the example of winding unit 7:
The winding unit 7 consists in its main parts of a discharge point 17 for a cop 18, a drive roller 20 provided with a reversing thread groove for a cross-wound bobbin 21 and a yarn guide assembly 261 which comprises various elements, such as, for example, thread tensioner, yarn cleaner, splicing device, paraffinizing device, by just a few to call.

At the front end frame 2 there is a bobbin delivery device 30, the bobbin deposit 29, upon request from one of the winding units 7 to 11 or at the request of further bobbin units, one after the other depositing the respectively requested bobbin, for example bobbin 31, on a conveyor belt 32 running in the direction of arrow 28 , which serves here as a cop conveyor. The upper run of the conveyor belt 32 slides along the crossbar 4. The lower run is carried by belt rolls 25.

A control device 5 is located on the cop supply device 30, from which a collecting cable 19 leads from control lines to the individual winding units 7 to 11. The control device 5 has a proximity sensor 44, which determines the passage of each cop 31 deposited on the conveyor belt 32 by the cop deposit 29.

The request for a new cop on the part of one of the winding stations is sent to the control device 5 via the collecting cable 19. The control device 5 then issues a cop issuing command to the cop deposit 29 via an operative connection 63. As soon as the deposited cop moves past the proximity sensor 44, the control device begins 5 a time count especially for the requesting winding unit. After the preset head transport time has elapsed, a switching command is sent from the control device 5 via the collecting cable 19 to an electromagnetic drive of a turnout, not shown here, for example the turnout 51 of the winding station 8 requesting, for example, which is in need of a new cop. This ensures that each requesting winding unit receives the cop intended for it. After receiving the switch 51 automatically resets. To derive a cop, the switch 51 is pivoted obliquely over the conveyor belt 32 in a known manner. The derived cop slides into the drain point 17 onto a pin 22 present there.

While the requested cop 31 travels on the conveyor belt 32 to the winding unit 8, the winding unit 7 lying in front of it is prevented from intercepting this cop. The cop requirements are fulfilled in their chronological order. The head start of the cop sent on the trip is always so large that none of the winding units located on the transport path can intercept this particular cop.

1 is the simpler representation because of the belt drive motor 6 of the conveyor belt 32 at the rear. It is connected to the control device 5 by a control line 39. In reality, the motor is at the other end of the conveyor belt 32 and pulls on the upper run. The control device 5 is provided with an optical and acoustic alarm device 40, which is intended to indicate a fault in the cop supply. There is an operative connection 41 from the belt drive motor 6 to the belt roller 42 of the conveyor belt 32.

At each winding unit 7 to 11 there is a controllable drive motor 12 to 16 for driving the cheese 21. The drive motors 12 to 16 have control devices 33 to 37. Each control device 33 to 37 has a preselectable winding speed control program. 2 and 3, two of these control programs are shown graphically. The control program according to FIG. 2 has a linear winding speed curve 45 falling with the winding time t. There is an association between the cop weight or the cop mass m, which is plotted on the lower abscissa, and the winding time t, which is plotted on the upper abscissa. The winding speed v is plotted on the ordinate.

In the present case, the maximum possible cop weight is 170 g and the sleeve weight is 40 g. The maximum winding time is 350 s.

Any start speeds can be selected on the winding speed curve 45, from which the winding speed follows the further course of the winding speed curve 45 as a function of time.

The winding speed control program according to FIG. 3 differs from the program according to FIG. 2 by a different course of the winding speed curve 46, which also has an influence on the respective remaining winding time.

The bobbin feed device 5, 29, 30, 32 has a yarn quantity measuring device 47. The bobbin requested by the respective winding unit, for example the winding unit 8, for example the bobbin 31, moves past the yarn quantity measuring device 47.

As can be seen in particular in FIG. 4, the yarn quantity measuring device 47 has a Kopswaage 43. The Kopswaage 43 is designed as a belt scale. The upper run of the conveyor belt 32 lies on the Kopswaage 43. The Kopswaage 43 rests on springs 48 and 49, which are supported against a base 23. The Kopswaage 43 is provided with a rod 24 pointing vertically downwards. The switching element 27 of a switch 28 is connected to the rod 24 by a spring 38. If the weight of a cop 31 is in addition to the weight of the conveyor belt 32 on the cop scale 43, the switch 28 closes a circuit which is connected to the rod 24 by an electrical voltage source 52 via the switch 28, the line 53, the flexible line 57 connected slide 59, a sliding resistor 61, the line 54, a line selector 64 and the line 66 leads to a timing relay 65.

4 to the control device 34 for the drive motor 13 of the drive roller 20 'of the winding unit 8. The drive roller 20' drives the cheese 21 'by friction.

From the line selector 64, further lines 55 and 67 to 69 lead to the other control devices 33 and 35 to 37 of the other winding units 7 and 9 to 11.

The sliding resistor 61 is a wire resistor on which the slide 59 picks up more or less turns depending on the altitude. The switching bridge 70 of the line selector 64 is set to the line which belongs to the winding unit requesting a cop. In the present case, this is the winding unit 8. The switching bridge 70 can be changed automatically in a manner not shown here before the switch 28 is closed or before a cop lies over the cop scale 43.

There are operative connections between the yarn quantity measuring device 47 and the control devices 33 to 37 of the drive motors 12 to 16 via the lines 55 and 66 to 69. The control devices 33 to 37 have means which determine the starting speed of the respective drive motor 12 to 16 according to a yarn quantity signal generated by the yarn quantity measuring device 47 based on measurements on the bobbin requested by the winding unit, for example the winding unit 8, for example on the bobbin 31 set, whereby the starting speed is lower the smaller the thread quantity signal.

This will be explained in more detail using the example of the control device 34 with reference to FIG. 4:
As soon as the Kopswaage 43 is loaded by a Kops, for example the Kops 31, the rod 24 moves vertically downwards, whereby the switch 28 is closed. However, the closed switch 28 allows the rod 24 to move further down.

This ensures the relatively weak spring 38. The slide 59 assumes a position on the sliding resistor 61 which corresponds to the respective cop weight.

The switching bridge 70 has previously been placed on line 66. This already happened at the time when the winding unit 8 requested a cop. Depending on the position of the slide 59 on the sliding resistor 61 after the switch 28 is closed, more or less turns of resistance wire are tapped. From the constant voltage source 52, a more or less strong current flows through the timing relay 65 of the control device 37 via the line 56 to ground. As soon as the current flows, the timing relay 65 switches on a switch 71, which switches a fast-running motor 72 to a voltage source 75 via lines 73, 74. The switch-on time of the timer relay 65 depends on the current in the line 66. After the time has elapsed, the timer relay 65 switches the switch 71 off again.

The rotor of the high-speed motor 72 sits on a shaft 76, which is mounted in the control device 37 and carries an eccentric cam 77. The outer edge of the cam disk 77 is designed according to the winding speed curve 45 of FIG. 2.

In a very short time, the fast-running motor 72 rotates the shaft 76 by an angle of rotation, the size of which depends on the respective head weight. Here, the cam plate 77 from its dash-dotted zero position 77 'out, for example, up to that shown in Fig. 4, the cop weight of the cop 31 corresponding position rotated with a solid line.

The rotor of a slow-running motor 79 is also seated on the same shaft 76, or the rotor of this motor is also connected to the shaft 76, for example via an overhaulable coupling.

The slow-running motor 79 - it can be a geared motor - can be connected to an electrical voltage source 87 via lines 80 to 82 and a switching element 84.

A two-armed scanning lever 88, which is pivotable about the pivot point 89, carries a scanning roller 90 at the upper end, which rests on the outer edge of the cam disk 77. A spring 91 is also attached to the upper end of the sensing lever 88. It carries a switching plunger 92 which, in the position shown in FIG. 4, resiliently holds a microswitch 93 in the switched-on state. The microswitch 93 is closed except for the zero position in all other positions of the cam plate 77. In the zero position 77 ', however, the force of the spring 91 is no longer sufficient to keep the microswitch 93 in the switched-on state. At the lower end, the scanning lever 88 carries the slide 60 of a sliding resistor 62. The slide 60 is connected to a flexible line 58 designed as a tension spring, which is connected to the drive motor 13 via a further line 94. The tension spring 58 also serves to load the scanning lever 88, so that the scanning roller 90 always bears against the outer contour of the cam plate 77. A line 95 leads from the sliding resistor 62 via a switch 86 and line 96 to a switching element 85. From there, a line 83 goes to line 82. The switch 86 is opened, for example, with each thread break or with each thread cleaning process. It is otherwise closed as long as the automatic winder 1 is in operation. The one in mass connected microswitch 93 is connected via a line 97, a switching element 99 and a line 98 to the switching coil of a contactor 100, the switching coil of which is also connected to the line 82. A switching rod 101 of the contactor 100 made of insulating material carries the three switching elements 84, 85 and 99, which are always switched on and off together.

Symbols indicate that the return line of the motors 13, 72 and 79 goes towards the fair.

4 shows in the control device 34 the switching elements 84, 85 and 99 as well as the switches 71 and 86 in the switched-off state, the microswitch 93 in the switched-on state. 4 shows the switch 28 in the switched-on state and the line selector 64 on the line 66 in the yarn quantity measuring device 47.

The line selector 64 can be set manually or automatically on the winding unit requesting a cop or on the line leading to the winding unit. For an automatic setting, the line selector 64 can also be replaced by a number of individual contactors corresponding to the number of winding positions. The switching rod 101 of the contactor 100 can be actuated either by its coil, by hand or by the plunger moving back and forth of an electromagnet, not shown here, which is actuated briefly when the winding unit needs a cop, so that all three switching elements 84, 85 and 99 are closed. The switch 86 can be switched on and off manually or by means of a yarn cleaner, not shown here. In normal operation, switch 86 is closed. The cam 77 is after unwinding a cop in the position 77 'and in this position the microswitch 93 is open so that the switching coil of the contactor 100 is de-energized and thereby the switching elements 84, 85 and 99 automatically get into the open position shown in FIG. 4.

Fig. 1 shows that at the winding unit 8 a cop has expired and that the sleeve of the expired cop has already been removed. The winding unit 8 now causes the control device 5 via the control line 19 to dispense a cop from the cop delivery device 30 via the cop deposit 29 onto the running conveyor belt 32. At the same time, the line selector 64 is placed on the line 66 leading to the control device 34. As mentioned above, this can be done automatically, for example by means of a pulse switching mechanism, not shown here, which switches the switching bridge 70 step by step.

Since the switch 28 is initially still open, nothing changes in the switching state until, for example, the cop 31 is transported over the scale 43. Now the scale swings out, closes the switch 28, at the same time briefly sets the sliding resistor 61 to a certain resistance value corresponding to the weight of the cops and thereby causes the time relay 65 to keep the switch 71 switched on until the fast-running motor 72 moves the cam disk 77 in has rotated the position shown in Fig. 4. Since the cam 77 embodies the winding speed control program according to FIG. 2 and the bobbin weight should be 100 g, the starting speed III is selected. Instead of a maximum possible winding speed of 1,100 m / min, unwinding will start at a starting speed of around 780 m / min. The winding time will not take a maximum of 350 s, but only about 210 s.

2, the winding speed curve 45 runs in a straight line from 400 to 1,100 m / min. Four selected starting speeds I to IV are shown on this straight line, which lead to cop weights of 160, 120, 100 and 80 g, corresponding to yarn weights of 120, 80, 60 and 40 g. The associated start speeds are 1,000, 850, 775 and 700 m / min. The zero point of the runtime is a cop weight of 30g, which is 10 g less than the actual cop weight of 40 g. This ensures that a cop is actually completely wound up. The winding time extends 10 s beyond the point in time at which the cop is completely processed by calculation. After the remaining time, the cam 77 is in the zero position 77 'according to FIG. 4th

After the requested cop 31 has passed the scale 43, the time relay 65 has been switched on for the time corresponding to the cop weight and the motor 72 has rotated the cam plate 77 accordingly, the cop 31 moves on to the requesting winding unit, and there it is by opening a switch derived from volume 32. In the case of the winding unit 8, this is the switch 51 which opens so that the cop slides down onto the pin 22 at the outlet 17. In the yarn guide unit 26 'of the winding unit 8, the end of the yarn is held. The example of the winding unit 7 shows that the yarn 102 runs over the yarn guide unit 26 and the drive roller 20 to the cheese 21. In the yarn guide unit 26 ', the connection of the new yarn end with the yarn end 103 of the cheese 21' is made. Thereafter, a yarn cleaner (not shown here) or the yarn connection device (not shown here) first switches on the switch 86 mechanically, if it was previously switched off, and also mechanically actuates the shift rod 101 by briefly shifting it to the right, so that all three switching elements 84, 85 and 99 close. The switching element 84 switches on the slowly running motor 79, so that from now on the cam 77 rotates slowly in the direction of the arrow 103, namely to its zero position 77 'corresponding to the predetermined remaining time.

The switching rod 101 is actuated only briefly, but the switching element 99 closes, which serves as a holding contact for the switching coil of the contactor 100. The contactor 100 can then only be switched off by the microswitch 93, and this only occurs after the cam disk 77 has rotated.

When the switch 86 and the switching element 85 are closed, the drive motor 13 receives current from the voltage source 87 via the sliding resistor 62 in accordance with the resistance tapped there. It starts at the intended starting speed and continuously reduces its speed in accordance with the increasing resistance of the sliding resistor 62. Before the scanning roller 90 springs back to the zero position because the cam slide 77 has completed a full revolution, the yarn runs out of the cop 31 and its Absence is found in the yarn guide unit 26 '. The existing yarn monitor or yarn cleaner first opens the switch 86, whereby the drive motor 13 comes to a standstill and then the cheese 21 'is brought to a standstill. The motor 79 runs for about 10 s longer until the scanning roller 90 jumps to the zero position, whereby the microswitch 93 is switched off. The switching coil of the contactor 100 is no longer flowed through by current, so that the switching rod 101 falls back to the left and all switching elements 84, 85 and 99 open. Reconnection is now prevented by opening the holding contact. A new cop can be requested and the processes are repeated.

If the cam disk 78 according to FIG. 5 is used instead of the cam slide 77, the winding speed runs according to the winding speed curve 46 according to FIG. 3. Here, the starting speeds V to VIII also relate to the bobbin weights 160, 120, 100 and 80 g. Here are the starting speeds of the The height is differently staggered, they range from 1,000 m / min to 940 m / min to 780 m / min and are therefore at a higher level overall than the starting speeds according to FIG. 2.

Alternatively, it can be provided that the switching element 85 is bridged by a switch 105, which can be actuated, for example, by a thread monitor or thread cleaner, until the signal "thread missing" occurs. This ensures that the yarn is safely unwound with minimum spooling time.

Alternatively, an optoelectric sensor 104, which detects the passing cops by measuring technology, can be arranged instead of the cop scales 43, the head signal of which, for example, acts on a servomotor which adjusts the slide 59 of the sliding resistor 51 in accordance with the amount of yarn.

Claims (10)

1. Process for evening out the yarn tension on rereeling cops to form cross-wound bobbins in an automatic reeler which has a plurality of winding heads, and on each winding head a controllable drive motor for driving the cross-wound bobbin and a cop supply arrangement with a cop conveyor supplying each individual winding head with cops, characterized in that each drive motor is controlled according to a pre-selectable bobbin speed control program with a bobbin speed curve whereby the bobbin speed is reduced with the reeling time, in that, with respect to the cop to be made ready for reeling for a specific winding head, the respective amount of yarn present on the cop tube is automatically detected and is processed into a yarn amount signal, in that the starting speed of the winding head is set in relation to the amount of yarn, and in that on the bobbin speed curve a starting speed is automatically selected which corresponds to the magnitude of the respective yarn amount signal, and which is the greater as the amount of yarn is the greater.
2. Process according to claim 1, characterized in that the amount of yarn of the cop is detected optoelectronically or gravimetrically.
3. Process according to claim 1 or 2, characterized in that the size of the cop profile and/or the weight of the cop are measured and are utilized as measurement for the amount of yarn or to produce the yarn amount signal.
4. Process according to one of claims 1 to 3, characterized in that the amount of yarn of the individual cop for several winding heads is established centrally, and in that the corresponding yarn amount signal is transmitted via the amount of yarn of a cop with the feeding of the cop to a winding head by the said winding head.
5. Process according to one of claims 1 to 4, characterized in that provision is made at each winding head for a sensor which detects the amount of yarn to be wound from the cop and in that the corresponding yarn amount signal is inputted into the bobbin speed control program of this winding head.
6. Process according to one of claims 1 to 5, characterized in that the sensor detecting the yarn amount of the cop is so designed that it detects the criteria of normal cops equal to full and of a cop one third full and emits corresponding yarn amount signals.
7. Process according to one of claims 1 to 5, characterized in that the bobbin speed is modified over the bobbin speed curve of the bobbin speed control program proportionally to the yarn amount signal detected during the unwinding of the cop.
8. Device for rereeling cops to form cross-wound bobbins in an automatic reeler which has a Plurality of winding heads, and on each winding head a controllable drive motor for driving the cross-wound bobbin and a cop supply arrangement with a cop conveyor supplying each individual winding head with cops, for carrying out the process according to one of claims 1 to 7, characterized in that the drive motors (12 to 16) have control devices (33 to 37), in that each control device (33 to 37) has a preselectable bobbin speed control program (Fig. 2, Fig. 3) with a bobbin speed control curve (45, 46) reducing with the reeling time (t), on which a starting speed (I, II, III, IV, V, VI, VII, VIII) is selectable, from which the bobbin speed (v), in time-dependent terms, follows the further course of the bobbin speed curve (45, 46), in that the cop supply device (5, 29, 30, 32) or the individual winding head has a yarn amount measuring device (47) which detects the yarn amount of the cop (31) to be made ready for the respective winding head (8), in that, between the yarn amount measuring device (47) and the control devices (33 to 37) of the drive motors (12 to 16), there are effective connections (55, 66 to 69) and in that the control devices which adjust the starting speed of the respective drive motor (12 to 16) according to a yarn amount signal generated by the yarn amount measuring device (47) and based upon measurements on the cop (31) demanded by the winding head (8), the starting speed (v) being all the smaller as the yarn amount is the smaller.
9. Device according to claim 8, characterized in that the yarn amount measuring device (47) has an optoelectronic sensor (104) operating according to the shading principle or the reflection principle, and/ or a cop weighing device (43).
10. Device according to either claim 8 or claim 9, characterized in that the yarn amount measuring device (47) is mounted centrally for all or part of the winding heads (8) of the automatic reeler in such a manner that the cops to be made ready (31) for the individual winding heads (8) travel through the common yarn amount measuring device (47).

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