EP2126170B1 - Method and apparatus for spinning staple fibres on ring-spinning machines - Google Patents

Abstract

Thread guiding device comprises a cap (33) arranged on an annular spindle (3) and connected to a twisting element (10) which has grooves (32, 35) on the periphery for taking up the thread (F) from the twisting element. An independent claim is also included for a method for spinning stacked fibers on a ring spinning frame. Preferred Features: The cap has a front surface arranged at a distance opposite the twisting element and contains a permanent magnet (31) forming a magnetic field with an opposite pole magnet on the twisting element. The cap has a cylindrical casing surface with grooves extending up to the front surface of the cap,.

Description

The invention relates to a method for spinning staple fibers, in particular short staple fibers on ring spinning machines, wherein a staple fiber warped in a drafting and twisted at the exit from the drafting to a thread and wound up by means of a ring / rotor device, wherein the emerging from the drafting fiber structure then passes through a thread guide, which has a equipped with a braking device twisting device, which drives synchronously driven with the spindle speed the fiber strand rotation, and an apparatus for performing the method.

It is a known fact that the threads on the ring spinning machine break mainly between drafting and thread guide in the so-called. Spinning zone. In this area, the emerging from the drafting fuse is not yet consolidated so much that it has grown each thread tension tip. In addition, the conventional thread guide, the so-called. Fadenführeröse only partially allows the rotation propagation of ring / runner in the spinning zone.

In order to solve this problem, the experts have been trying for many decades with numerous proposals, it has been proposed, for example, so-called crowns to put on the ring spindle to make the outgoing from the circulating on the ring rotor spin direction towards the spinning triangle out more effective and in the critical area to achieve a better consolidation of the emerging from the drafting fuse ( DE 1 116 584 ). In these spindle attachments, the thread lies in the teeth of the crown and is taken through them, but the yarn on the Krone make the same backward movement as the rotor on the spinning ring, which remains behind the peripheral speed of the spindle according to the winding and the winding speed. The thread is held back in the crown of the crown until the tension is so great that the thread jumps into the next point. The thread thus jumps from jag to jag backwards according to the lingering of the runner. The resulting friction leads to yarn damage and roughening of the yarn, which is undesirable. In addition, each jump creates a surge, resulting in uneven rotation and engagement of the fibers as they exit the drafting system. It is therefore anxious to provide as little as possible pips. When so-called. Spinnfinger as attachment to the ring spindle, only one point is present. The spin finger is smooth and roughens the yarn less. However, the spin finger works practically like a crown with a point through which the yarn is taken. This means that the jump is much bigger, almost a turn. This Spinnfingerlösung therefore leads to large thread breaks and causes thread breaks and uneven yarn.

From the DE 196 29 787 A1 a rotating yarn guide is known which is arranged as a swirl device between the usual yarn guide on the spindle and the ring rotor directly above the ring spindle, wherein a rotary body is entrained by means of a magnetic coupling of the spindle.

The fiber structure is introduced centrally and led out laterally from the rotary body, from where the fiber structure extends in a balloon to the ring traveler. Alternatively, the rotary body should have a helical channel and be driven independently of the spindle slower or faster than the spindle. This should be the fiber structure temporarily superimposed a small false twisted wire.

By the upstream thread guide, however, the rotation generated hinders their propagation to the drafting system exit. Also, this known device has not been able to introduce in practice, since no defined rotation distribution takes place and, moreover, the external drive is too expensive.

In order to avoid these disadvantages, it has been proposed ( WO 2004/072339 ), to arrange a thread guiding device with a swirl element at a distance above the upper end of the ring spindle and to couple this swirl element via a magnetic force field with the ring spindle. The swirl element has a thread brake device which consists of a coaxially extending to the axis of rotation core around which the yarn guide passing yarn is herumschlingbar and disposed on the core driving edge. As a result of this design of the thread guiding device, a defined entrainment of the thread by the swirl element takes place, so that the thread is given defined rotation in the critical region between the thread guiding device and the drafting device. The winding is effected continuously and smoothly. This thread guide has proven extremely good. In the critical region between drafting and thread guide device more than 100% of the rotation is achieved in the thread F 'in front of the spinning triangle, based on the desired rotation in the finished yarn. Jumping over crown pips or the like is no longer necessary, as well as the imponderabilities of a twisting by friction. This leads to a nearly yarn breakage-free spinning.

The spinning speeds could be increased considerably. By reducing the size of the spinning triangle and the resulting better integration of the fibers, not only increased productivity but also a considerable improvement in the quality of the thread has been achieved. Although the balloon diameter is reduced so that balloon constriction rings are largely unnecessary, now allow higher spin speeds an increased energy demand. In addition, by the coupling element on the spindle head for entrainment of the swirl element an enlargement of the balloon and thus the balloon resistance and the power consumption is caused.

Object of the present invention is to reduce energy consumption in a thread guide device of this known type and thus to enable the higher production rates and economic. This object is solved by the features of claims 1 and 6.

Characterized in that the emerging from the drafting fiber assembly passes through a equipped with a twisting device yarn guide, which is driven synchronously with the spindle speed, the fiber strand in the critical section to drafting equipment outlet rotation is issued, so that the twisting device leaves a finished twisted thread firmly is, so that, surprisingly, the feared roughening of the thread by a grooved spindle attachment does not occur. By the swirl device downstream spindle attachment now the thread balloon is suppressed, so that no high balloon tension forces. It eliminates the thread F opposing air resistance. This results in a significant energy savings.

The braking of the thread in the twisting device prevents impacts coming from the grooves of the spindle attachment from propagating into the twisting zone. This braking device makes it possible to keep the total thread tension low, and to let the rotation produced by the swirl element fully effective up to the spinning triangle. The thread friction generated by the attachment is negligible, so that an excellent thread quality is produced despite very high spindle speeds. By applying the claimed method can be spun at a double spindle speed without significant thread breaks and quality losses.

By arranged on the ring spindle, the swirl element downstream Tower is the twist distribution and the balloon suppression separated. Each of the two elements can be designed and optimized according to its task. Surprisingly, it has been shown that considerable energy savings can be achieved by the downstream connection of a spindle attachment according to the swirl element, without impairing the yarn quality achieved by the swirl element of the thread guiding device, so that only through this combination can the advantages of this thread guiding device with swirl element be fully exploited, namely high productivity and quality with simultaneous energy savings. For entrainment of the swirl element by the spindle, the attachment has a spaced-apart from the swirl element end face containing a permanent magnet which forms a magnetic force field for entrainment of the swirl element with a gegenpoligen magnet on the swirl element. The article itself expediently has a cylindrical lateral surface, in which extending into the end face of the essay extending grooves are provided so that they can easily detect the emerging from the swirl element thread.

Due to the centric exit of the thread from the swirl element with respect to the end face of the attachment, exact geometrical conditions are guaranteed which cause an exact entrainment of the thread. The diameter of the attachment resembles the spindle diameter adjoining the attachment, so that the thread entrained by the attachment winds easily and inevitably around the spindle and thus no balloon is formed. There are different versions of the essay possible. The diameter of the attachment may extend beyond the subsequent spindle diameter by the groove depth. But it is also useful and gentle for the thread when the grooves expire with their groove bottom on the adjoining spindle diameter. Due to the separation of twist distribution and balloon suppression, there is the advantage that only the gentle entrainment of the thread is to be considered in the design of the spindle attachment.

Due to the exact predetermined geometry of the yarn path, it is not necessary that the grooves extend over the full length of the lateral surface of the essay. It has proven to be advantageous and expedient to equip the article at its end facing the yarn guide element 1 end with a shank which projects beyond the shank diameter of the attachment 33 and which is provided with grooves. The grooves are adapted in their orientation and length of the geometry of the yarn path. It is sufficient for a good entrainment that the grooves cut through the edge of the rim formed by the end face and the lateral surface at an angle α.

To avoid large jumps and thus impacts in the thread, the number of grooves should be as large as possible. It has proven to be useful to adjust the width of the grooves about twice the yarn diameter. The depth of the grooves is suitably about half a groove width. As a result, a slight catching of the thread, but also a good release of the thread is ensured in the next groove, without excessive voltages and surges occur. The quality of the thread is not affected in this way.

Fig. 1

das Drallelement mit dem nachgeschalteten Spindelauf- satz;

Fig. 2

eine Gesamtanordnung der Spindel mit Spindelaufsatz und Drallelement;

Fig. 3 und 4

verschiedene Ausführungsformen des Spindelaufsatzes;

Fig. 5

Vergleich der Leistungsaufnahme mit und ohne Spindel- aufsatz;

Fig. 6

eine andere Ausführung des Spindelaufsatzes.

Further details of the invention will be explained with reference to the drawings. Show it:

Fig. 1

the swirl element with the downstream spindle attachment;

Fig. 2

an overall arrangement of the spindle with spindle attachment and swirl element;

3 and 4

various embodiments of the spindle attachment;

Fig. 5

Comparison of power consumption with and without spindle attachment;

Fig. 6

another embodiment of the spindle attachment.

The thread guiding device consists of a thread guiding device 1 arranged above the spindle, which has a swirl element 10 which contains a braking device. This braking device consists of a driver 13, which has a coaxially to the axis of rotation extending core 13 ', around which one of the spindle 3 to the drafting equipment outlet extending thread F is herumschlingbar, which is still unfinished in its upper part F'. At this core 13 ', an upper edge 15 and a lower edge 15' is provided, on which the thread guide 1 continuous thread F is applied and taken on rotation of the swirl element 10.

The spindle 3 facing part of the swirl element 10 is formed as a magnet and forms with the attachment 33 of the spindle 3, which is also equipped with permanent magnets 31, a magnetic coupling, so that the swirl element 10 rotates at the same speed as the spindle 3. The distance of the spindle attachment 33 from the swirl element 10 is determined in a known manner by the magnetic field, which is necessary to ensure entrainment of the swirl element 10 by the spindle 3. As a rule, this distance is about 5 to 10 mm.

The thread guide device 1 with the swirl element 10 is an attached to the spindle 3 essay 33 downstream. This attachment 33 expediently has a cylindrical shell shape, in which grooves 32 are provided, which extend into the end face 34 of the attachment 33. The grooves can be designed differently. It is important that the thread F is protected in its entrainment by the grooves. The diameter of the attachment 33 can project beyond the subsequent spindle diameter by the groove depth ( 3 and 4 ). However, it is also expedient and gentle for the thread F, if the grooves 33 with their groove bottom on the subsequent spindle diameter ( Fig. 1 and 2 ) or attachment diameter ( Fig. 4 ) leak.

The thread guiding device 1 is arranged over the end face 34 of the attachment 33 in such a way that the thread F exiting from the twist element 10 emerges centrically with respect to the end face 34. As a result, an exact geometry of the thread F is independent of the rotation of the spindle 3 given the transition into the grooves 32 of the attachment 33. By the grooves 32, the thread F is detected easily and safely and taken so long until the tension in the thread F is so great that it jumps out of the groove 32 in the next adjacent groove 32 by the remaining rotor 63. By caused by the lagging of the rotor 63 train, the tension in the thread F is increased so that no balloon is formed, but the thread F spirally wraps around the attachment 33 and the spindle 3.

Due to the fact that the yarn F leaves the swirl element 10 as a finished yarn F and, due to the arrangement of the swirl element 10 over the spindle attachment 33, prescribes an exact geometry for the yarn path, irregular jumps or an irregular catching of the yarn F are avoided. The grooves 32 need not even be very pronounced and sharp-edged to catch the thread F and hold it. This protects the thread and prevents roughening. It has proven expedient to dimension the depth of the grooves 32 to be approximately half the width of the grooves 32. This makes it possible to lift the thread F out of this groove 32 with only a slight pull. The surges are low and the friction on the thread F also, so that the quality of the thread is not affected. To avoid large jumps, it is expedient to arrange as many grooves 32 on the circumference of the attachment 33. Thus, the differences in length and the jumps of the thread F are small.

FIG. 6 shows another embodiment in which the spindle attachment 33 at its end facing the yarn guide element 1 has a collar 36 projecting beyond the shaft diameter of the attachment 33, which is provided with grooves 35. These grooves are in their orientation and length of geometry adapted to the yarn path. They run inclined to the axis of rotation of the attachment 33 and cut through the edge of the rim 36 formed by the end face 34 and the lateral surface at an angle α. This angle α is determined by the central exit from the yarn guide element 1 and the yarn path, under which the yarn F reaches the edge 35 of the rim 36 provided with the grooves 35. These grooves 35 are rectangular in cross-section, but in their longitudinal section they form a triangle. Through the apex of this triangle, the thread F guided over the edge is caught and held back. F _{2 shows} another position of the thread F as it passes through the groove 35. This formation of the groove 35 causes a controlled and therefore very regular catching and releasing the thread F, so that it receives a regular rotation and little abrasion. The thread F runs out of the groove 35 freely over the shaft of the attachment 33 on the sleeve 4, where it slides down to the ring / rotor device without ballooning.

The emerging from the drafting fiber structure F 'runs instead of the conventional yarn guide (Sauschwanz) a yarn guide device 1 with a twisting device 10, which is driven synchronously with the spindle speed and the fiber strand F' thus granted rotation. The entrainment of the swirl element 10 by the spindle 3 is effected by a magnetic coupling 1, 10, so that the swirl device 10 leaves a finished twisted thread F. Immediately after leaving the twisting device 10 of this finished twisted yarn F is guided over a provided with grooves 32 and 35 spindle attachment 33. The thread F is detected by the grooves 32, 35 and taken with respect to the rotor 63 by the spindle 3 with the spindle rotation. Since the rotor 63 is left behind, the known effect occurs that due to the increased tension in the thread F, no balloon is formed, but the thread F wraps around the attachment 33 and the sleeve 4 before it reaches the ring / traveler device and is wound up. The twisting device 10 is further provided with a braking device. By this braking device surges are attenuated and compensated, so that this on the Spinning line between drafting system exit and swirl element can not affect. The given rotation propagates unhindered and completely to the drafting system exit. The swirl element 10 is immediately followed by the attachment 33 provided with grooves 32, 35. The balloon suppression is independent of the rotation process.

The swirl element 10 is aligned exclusively to the swirling, while the spindle attachment 33 detects a finished twisted thread F, which is largely insensitive to the entrainment by the grooves 32, 35 detecting it. The spindle attachment 33 and the grooves 32, 35 are designed exclusively for balloon suppression, wherein the braking device provided in the swirl device almost completely compensates for the shocks resulting from jumping from one groove 32, 35 into the other.

The rotation process takes place continuously without disturbances and takes place exclusively in the area between the drafting system exit and the swirl element. The deceleration of the thread F in the twisting device 10 plays a decisive role here. By this braking device, the thread tension can be regulated and kept low overall. The frictional stress of the thread F through the grooves 32, 35 of the spindle attachment 33 is therefore small. The thread quality is not affected. By changing the wrap angle, the braking effect can be regulated. A half or a wrap has proven to be optimal for the braking of the thread F with simultaneous balloon suppression. Further details are given in the earlier application of the same inventors ( WO 2004/072339 A1 ).

Against this frictional stress, the thread is therefore already largely insensitive, because the swirl element 10 leaves a finished twisted thread F. Investigations have shown that compared to a conventional yarn guide, with about 93% of the rotation of the finished yarn can be achieved with the swirl element 10 more than 100% rotation in the range of the spinning triangle can be achieved. If the spindle attachment 33 is used without swirl element 10, the friction on the shaft of the spindle 3 and the spindle attachment 33 results in a rotation jam, wherein even only 85% of the rotation is present in the region of the spinning triangle. This has in the past led to unacceptable quality losses in the thread, especially when spinning short staple fibers, as well as frequent thread breaks.

1. a) Drallelement mit Fadenbremse ohne Balloneinengungsring;
2. b) das Drallelement mit Fadenbremse und nachgeschaltetem Spindelaufsatz (unterdrückter Fadenballon).

If, in addition to the swirl element 10, a grooved spindle attachment 33 is used, considerable speed improvements are achieved in addition to the considerable improvement in quality and almost spall-free spinning, whereby, despite the increased speed, a considerable lowering of the energy requirement occurs compared to spinning without a spindle attachment. In FIG. 5 For example, the comparison of the power consumption shown when spinning a yarn of fineness Nm 40 with

1. a) swirl element with thread brake without balloon constriction ring;
2. b) the swirl element with thread brake and downstream spindle attachment (suppressed thread balloon).

As can be seen from the graph, with spindle attachment 33 speeds of 26,000 revolutions could be achieved, while spinning without spindle attachment 33 was not possible. While at 18,000 revolutions the power consumption of spindle 3 when spinning with spindle attachment 33 was 16% lower than without spindle attachment 33, at 24,000 revolutions the difference was even 38%, ie with increasing rotational speed the power requirement for spinning with spindle attachment 33 decreased considerably a spinning without this spindle attachment. It follows that, especially at high spindle speeds, the use of the downstream spindle attachment has a particularly favorable effect on the energy requirement: With almost a doubling of the spindle speeds, the energy requirement only increases by 38%. Surprisingly, the thread quality does not decrease and the spinning is almost thread break free. Significant energy savings are achieved with increased production efficiency and the spinning of short staple with suppressed balloon without affecting the yarn quality allows.

Claims (17)

1. Method for spinning staple fibers on ring spinning machines whereby a staple fiber composite is drawn in a drawing frame, twisted together to form a thread as it emerges from the drawing frame and wound up by means of a traveler device whereby the fiber composite (F') that emerges from the drawing frame subsequently runs through a thread-guiding device (1) equipped with a twisting apparatus (10) that has a braking device (13, 13') and that imparts a twist to the fiber composite (F') driven synchronously with the number of spindle revolutions so that a fully twisted thread (F) comes out of the twisting apparatus (10), characterized in that the fully twisted thread (F) is led through a spindle attachment (33) with grooves (32, 35) in such a way after immediately leaving the twisting apparatus (10) that the thread (F) is grasped by the grooves (32, 35) before it reaches the traveler device (6, 62, 63) and is wound up.
2. Method according to Claim 1, characterized in that the thread (F) is centrically guided out of the twisting apparatus (10) and moved towards the grooves (32) of the spindle attachment (33) that is coaxially arranged with regard to the twisting apparatus (10).
3. Method according to one of the Claims 1 or 2, characterized in that the speed of the thread (F) in the twisting apparatus (10) is reduced by braking.
4. Method according to one or several of the Claims 1 through 3, characterized in that the speed reduction achieved by braking in the twisting apparatus (10) is coordinated in such a way that the thread tension is maintained at an overall low level but possible thread tension jolts can be compensated in spite of that.
5. Method according to one or several of the Claims 1 through 4, characterized in that the thread (F) is grasped by as many grooves (32) as possible and then released again.
6. Device for spinning staple fibers on ring spinning frames with a thread-guiding device located between drawing frame outlet and ring spindle, equipped with a twisting element arranged at a distance above the upper end of the ring spindle and coupled with the ring spindle via a magnetic force field so that the twisting element turns with the same speed as the ring spindle, in which case the twisting apparatus (10) is equipped with a thread-braking device (12, 13), characterized in that an attachment (33) arranged on top of the ring spindle (3) is installed downstream from the twisting element (10) and has circumferential grooves (32, 35) for catching the thread (F) coming out of the twisting element (10).
7. Device according to Claim 6, characterized in that , arranged at a distance from the twisting element (10), the attachment (33) has a front part (34) that contains a permanent magnet (31) that creates a magnetic force field with a magnet of the opposite pole on the twisting element (10) for taking the twisting element (10) along with it.
8. Device according to one of the Claims 6 or 7, characterized in that the attachment (33) has a cylindrical surface area in which grooves (32, 35) have been arranged that extend into the front surface (34) of the attachment (33).
9. Device according to one or several of the Claims 6 through 8, characterized in that the thread (F) comes out centrically from the twisting element (10) in front of the front part (34) of the attachment (33).
10. Device according to one or several of Claims 6 through 9, characterized in that the diameter of the attachment (33) equals the spindle diameter arranged downstream to the attachment (33).
11. Device according to one or several of Claims 6 through 10, characterized in that the diameter of the attachment (33) exceeds the spindle diameter arranged downstream by the groove depth.
12. Device according to one or several of Claims 6 through 11, characterized in that the grooves (32) end with their groove bottom on the spindle diameter arranged downstream.
13. Device according to one or several of Claims 6 through 10 or 12, characterized in that the attachment (33) on the side facing the ring spindle (3) has a belt (35) that ends in the grooves (32) and protrudes from the subsequent spindle diameter (33).
14. Device according to one or several of Claims 6 through 9, 12 and 13, characterized in that the attachment (33) on its end that faces the thread-guiding element (1) has a collar (36) with grooves (35) that protrudes from the shaft diameter of the attachment (33).
15. Device according to one or several of Claims 6 through 14, characterized in that the grooves (32, 35) in their orientation and length are adapted to the geometry of the run of the thread.
16. Device according to one of the Claims 14 or 15, characterized in that the grooves (35) intersect the edge of the collar (36) created by the front part (34) and the surface area at an angle α.
17. Device according to one or several of Claims 6 through 16, characterized in that the width of the grooves (32, 35) corresponds roughly to twice the diameter of the yarn and/or the depth of the grooves (32, 35) corresponds to one-half of the groove width.

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