EP3140232B1 - Textile machine for the production of roving and method for operating the same - Google Patents

Description

The present invention relates to a method for operating a textile machine which is used for the production of rovings, wherein during roving production with the aid of at least one consolidation agent a roving having a protective twist is produced from a fiber structure supplied to the consolidation agent, the rovings produced by the consolidation agent using a winding device is wound onto a sleeve, the roving being guided during winding by means of a guide element arranged between the strengthening means and the sleeve, and the guide element exerting a braking action on the roving. In addition, a textile machine for producing a roving is proposed, the textile machine having at least one consolidation agent, with the aid of which a protective rotation can be imparted to a fiber structure supplied to the consolidation agent, and wherein the textile machine has at least one winding device, with the aid of which the roving can be wound onto a sleeve is.

Roving is made from fiber ribbons, which are usually pretreated with the help of draw frames and serves as a template for the subsequent spinning process, in which the individual fibers of the roving are spun into a yarn, for example using a ring spinning machine. In order to give the roving the necessary strength for further processing, it has proven to be useful to stretch the submitted fiber structure during the production of the roving with the help of a drafting device, which is usually part of the corresponding roving machine, and then to provide a protective twist. The stated strength is important in order to prevent the roving from tearing when it is wound up on a tube or while it is being fed to the downstream spinning machine. On the one hand, the protective rotation given must be strong enough to ensure that the individual fibers are held together during the individual winding and unwinding processes and corresponding transport processes between the respective machine types. On the other hand, despite the protective twist, it must be ensured that the roving can be processed further in a spinning machine - the roving must therefore continue to be able to be warped.

To produce a corresponding roving, so-called flyers are primarily used, but their delivery speed is limited due to centrifugal forces that occur. There have therefore already been numerous suggestions for bypassing the flyer or replacing it with an alternative type of machine (see for example EP 0 375 242 A2 , DE 32 37 989 C2 ).

Among other things, it has already been proposed in this connection to produce roving with the help of air spinning machines, in which the protective rotation is generated with the help of swirling air currents. The basic principle here is to guide a fiber structure through a solidifying agent designed as an air spinning nozzle, in which an air vortex is generated. Finally, this causes part of the outer fibers of the supplied fiber structure to be looped around the central fiber strand as so-called wrapping fibers, which in turn consists of core fibers running essentially parallel to one another.

Another method for roving is in the DE 24 47 715 A1 disclosed. The consolidation of the unconsolidated fiber bandage described there takes place with the aid of a strengthening agent, which does not twist, but rather spirally wraps around a fiber band through one or more filament yarns, preferably monofilament filament yarns, which hold the fiber bandage together and give it its strength. The spirals of the individual filament yarns can be arranged in the same direction or in opposite directions. Two filament yarns are preferred, which are arranged in opposite rotation or intersecting. The roving produced in this way is thus essentially composed of a sliver of parallelized staple fibers and one or more fine-titer filament yarns wrapping around the sliver in a spiral.

There are various ways of overcoming the unconsolidated fiber structure with the filament yarn or filament yarns. For example, the filament yarn can be applied to small spools of small diameter. The filament yarn is then withdrawn from the fixed bobbin and pulled together with the fiber assembly through the bobbin axis, the fiber assembly from Filament yarn is wound and the number of windings drawn from the bobbin corresponds to the number of turns applied to the fiber structure. In principle, it is also possible to design the strengthening means in such a way that only the unconsolidated fiber structure is passed through the bobbin axis in order to thereby lay the winding process behind the filament yarn bobbin. The winding point should be determined by a suitable thread guide.

Another process for the production of roving describes the WO 2009/086646 A1 , the method comprising the following steps: 1) providing a fiber structure in the form of two, preferably untwisted, fiber bands, 2) issuing S and Z twists over alternating regions of the two fiber bands, regions of S and Z twists are separated on the respective sliver by areas without rotation, 3) bringing together the two slivers provided with S and Z twists to form a roving, the two slivers twisting automatically due to their tendency to turn back.

The S and Z rotations can e.g. B. are generated by means of two elements of the solidifying agent used, which hold the respective sliver by clamping, with at least one element, preferably both elements, giving the sliver through a relative movement on its surface transversely to the longitudinal direction of the sliver on both sides alternately opposite rotations. At the same time, the respective sliver is moved in the sliver direction. However, the S and Z rotations can also be generated using an aerodynamic, in particular pneumatic, process.

The alternating S and Z rotations are also interrupted by changing areas without rotation. The two slivers provided with S and Z twists in the same way are finally brought together at the so-called union point. Here the slivers start to twist automatically, ie they wind around each other. This so-called piling maintains the S and Z twists in the individual fiber bands, so that a self-stabilizing two-component roving is created. Basically, however, it should be noted that the areas without rotation in the first sliver should be staggered in the longitudinal direction to the areas without rotation in the second sliver, so that two areas without rotation of the first and second sliver in the resulting roving are never next to each other, since the strength of the roving essentially depends on the phase position which depends on areas without rotation of the two slivers. The rovings are therefore, as described above, always brought together with the strengthening agent so that their areas are out of phase without rotation. The roving produced in this way finally has a higher strength than a non-twisted fiber composite, which in the end is sufficient to wind the roving onto a spool without any distortion and to unwind it again.

In any case, it has proven useful to guide the roving leaving the textile machine with the aid of a traversing arm that moves back and forth parallel to the axis of rotation of the sleeve to be spooled, in order to give the finished bobbin (sleeve with spooled roving) the desired shape. In addition, the oscillating movement ensures that the roving is wound on top of one another in individual layers so that it can later be unwound from the spool without fear of tearing the roving.

In order to achieve the desired bobbin build-up, however, it is essential to apply a certain amount of tension to the roving during the winding-up process, since this could otherwise lead to undesired loop formation on the bobbin surface, in which case the subsequent unwinding process would be negatively influenced.

It is therefore an object of the present invention to regulate the tensile force acting on the roving in such a way that reliable winding is possible without the formation of the loops mentioned, and it should also be ensured that the roving does not tear during winding due to the tensile force acting on the roving.

The object is achieved by a method and a textile machine with the features of the independent claims.

According to the invention, the roving is now guided during winding onto a sleeve with the aid of a guide element arranged between the strengthening means and the sleeve, the guide element exerting a braking effect on the roving caused by friction between the roving and the guide element (the braking effect is generally necessary in order to gradually reduce the tensile force exerted by the rotating sleeve on the roving and thus prevent the roving from tearing between the sleeve and the strengthening agent or sleeve and the trigger unit).

In addition, it is provided that the braking effect is adjusted during the operation of the textile machine in such a way that it is brought into contact with a, preferably empty, sleeve during a starting process, during which the roving leaving the setting agent and / or during a sleeve change, during this an exchange of a spooled tube by an empty tube is less than during normal operation between the starting process and the tube change, during which the roving is wound onto the tube until a certain degree of filling is reached.

If the roving is braked relatively strongly by the guide element during the normal operation mentioned (i.e. during the winding process lying between the starting process and the tube change), a correspondingly high tensile force is necessary to pull the roving over a corresponding guide surface of the guide element and finally onto it Winding the bobbin. The roving can therefore be wound up tightly onto the sleeve, resulting in a compact package construction. The necessary tensile force is preferably transmitted through the rotating sleeve to the roving, the sleeve should be equipped with an appropriately dimensioned sleeve drive. As a result, the high braking effect during winding ensures that the roving can be wound onto the sleeve under tension after leaving the setting agent.

On the other hand, only a limited tensile force can be transferred to the roving during the start or sleeve change process, since it is not yet gripped by the sleeve at this stage. Especially if that is produced by the solidifying agent Roving is sucked in with a suction unit during the starting process or during a sleeve change, the tensile force acting on the roving is limited, since this is generated exclusively by the air flow generated by the suction unit (which sucks the roving into the suction unit). If the braking effect of the guide element compared to normal operation were not reduced at this stage, the tensile force generated by the suction unit would not be sufficient to suck in the roving against the braking effect of the guide element. In this case, the roving produced by the strengthening agent would also not be able to be passed on to the sleeve, so that the normal operation mentioned could not be achieved at all.

By adapting the braking effect according to the invention, it is thus possible to pull the roving over the guide surface of the guide element with a relatively low tensile force during the start and sleeve change process, so that, for example, a suction unit under vacuum can be used for this. At the same time, the tensile force acting on the roving can be increased by increasing the braking effect of the guide element after completion of the respective starting or sleeve changing process, so that the roving can be wound onto the sleeve with the desired tension.

At this point, it should generally be pointed out (and thus also in connection with the textile machine according to the invention described in more detail below) that the stated strengthening agent can be designed differently. For example, it would be conceivable that the strengthening agent is suitable, the roving on the in the above-mentioned documents WO 2009/086646 A1 and DE 24 47 715 A1 to produce the manner described.

However, the textile machine is preferably designed as an air spinning machine and the consolidation means as an air spinning nozzle, through which the protective rotation of the roving, as described above, is generated with the aid of vortex air flows (a section of a corresponding textile machine designed as an air spinning machine is described by way of example in the description of the figures).

In any case, it is advantageous if the braking effect is changed by reducing or increasing the contact area over which the roving is in contact with the guide element. The contact surface should at least partially deviate from a flat surface and, for example, be curved or curved, since the enlargement of the contact surface in a flat surface would not lead to an increase in the friction between the contact surface and roving and thus would not increase the braking effect. The guide element should also have guide sections which guide the roving in such a way that it passes the guide element on a predetermined path. The guide element or elements can comprise, for example, elevations and / or depressions which guide the roving accordingly.

It is also advantageous if the guide element is wrapped in the roving over a wrap angle, the braking effect being changed by changing the wrap angle. For this purpose, the guide element preferably has a guide surface which is formed by a surface section of a cross-section, for. B. round or oval guide rod is formed. In addition, the guide element can be wrapped less or more than once by the roving during a start or sleeve changing process as well as during normal operation of the textile machine. The level of braking effect is ultimately directly related to the number of wraps, which of course does not have to be an integer. The direction of the turns also need not be uniform. For example, it would be possible for the roving to loop around the guide element in a first area in a first winding direction, while there is an opposite winding direction in the remaining area. The braking effect, which arises from the friction between the roving and the guide element, can finally be influenced by winding or unwinding the roving on the guide element, with winding resulting in an increase in the braking effect and vice versa. The winding and unwinding can be done by rotating the guide element or individual sections thereof, wherein the guide element can comprise a gripper which guides the roving, only the gripper having to be rotated about an axis of rotation in order to bring about the desired change in the wrap angle.

It is also extremely advantageous if the wrap angle during the winding process has at least temporarily an amount that is between 400 ° and 2000 °, preferably between 500 ° and 1800 °, particularly preferably between 600 ° and 1600 °. In this context, it should generally be pointed out that an amount of over 360 ° means that the guide element is wrapped in the roving more than once. For example, a wrap angle of 540 ° is equivalent to 1.5 wraps, a wrap angle of 720 ° means two wraps, etc. If the value lies between the above amounts, it is ensured that the roving with a relatively high tensile force over the guide surface of the Guide element must be pulled and thereby subjected to a relatively high tension before winding on the sleeve. The result is the desired compact bobbin with roving layers close together.

There are also advantages if the wrap angle during the starting process and / or the sleeve change has at least temporarily an amount that is between 50 ° and 1000 °, preferably between 75 ° and 720 °, particularly preferably between 100 ° and 500 ° . In contrast to normal operation, the braking effect in this case is relatively low, so that the roving (which at least at the beginning of the starting process and / or a sleeve change is not in contact with the sleeve and therefore cannot be pulled by the sleeve over the guide surface of the guide element ) can be moved with the help of an air flow. The air flow is preferably generated by a suction unit which sucks in the roving produced by the strengthening agent until it is gripped by the sleeve and wound up by its rotation.

It is also advantageous if, due to the braking effect, a tensile stress acts on the portion of the roving which is in contact with the guide element, the braking effect being adapted such that the average amount of said tensile stress during the winding process is at least twice, preferably at least four times, particularly preferably is at least eight times, higher than during the starting process and / or during the sleeve change. If the amount is in the specified range, the roving can only be used during the start or core change process low tensile force are pulled over the guide surface, the higher braking effect during normal operation ensuring that the stated tensile force must be correspondingly high, resulting in a tight winding of the roving.

There are also advantages if the increase in the braking effect is at least 10 seconds, preferably at the latest 6 seconds, particularly preferably at the latest 4 seconds, after the roving comes into contact with an empty sleeve provided by the winding device during the starting process or during the tube change is increased. After this time, the sleeve is already wrapped in the roving several times, so that the further tensile force can already be transferred to the roving during further winding, in order to be able to pull it over the guide surface of the guide element despite the increased braking effect. The braking effect can be increased abruptly or gradually, for example by increasing the wrap angle of the roving in the region of the guide element. Finally, the braking effect should remain constant during normal operation, although changes are of course not excluded.

Furthermore, it is advantageous if the braking effect is increased while a first to 600th turn, preferably during a first to 300th turn, particularly preferably during a first to 100th turn, of the roving is wound onto an empty tube. In contrast to the variant described in the previous paragraph, the braking effect in this case is not increased depending on the time, but on the number of turns. The number can be determined with the aid of a corresponding sensor, which determines the number, for example, from the speed of the sleeve.

It is also advantageous if the braking action during the winding process is at least 0.01 seconds, preferably at least 0.5 seconds, particularly preferably at least 1 second, and / or a maximum of 20 seconds, preferably a maximum of 10 seconds, particularly preferably a maximum of 5 seconds, before the start of a pending one Sleeve change is reduced. It would also be possible to reduce the braking effect only when the sleeve changing process begins, ie when a wound sleeve is removed from the area in which it was wound. However, the sleeve will change during the sleeve change moved away from the guide element, for example rotated away with the aid of a rotating sleeve changing device, the tensile force exerted by the rotating sleeve on the roving is added to the tensile force exerted on the roving by moving the sleeve away, so that it maintains the braking effect would cause the roving to tear.

As a result, the roving is wound onto the sleeve relatively tightly, so that the volume of the finished bobbin is relatively small compared to the amount of roving spooled on. The roving spooled onto the tube at the start of a winding process thereby has a lower tension than the roving spooled after the start-up procedure and / or tube change. In return, however, the risk that the roving tears outside of normal operation in the sections mentioned is significantly minimized.

There are also advantages if the roving is moved between defined turning points with the help of the guide element, at least during the winding process, in order to be able to wind the roving onto the sleeve in several layers. The traversing preferably takes place in a direction running parallel to the axis of rotation of the sleeve.

It is also advantageous if the production of the roving is not interrupted during the sleeve change, the roving produced by the strengthening agent being spooled onto the spool that was spooled before the sleeve change at least until it is empty due to the sleeve change Sleeve comes into contact. The sleeves can be changed, for example, with the aid of a rotating carrier which has at least two sleeve positions. If one of the sleeves has been sufficiently spooled with roving, the carrier is rotated until the full sleeve located on the first spool position has reached the area in which it was spooled with roving. As a result, an empty tube (which is located on the second tube space) finally reaches the area mentioned and can be spooled with roving without a separate starting process being necessary for this.

It is particularly advantageous if the roving is guided continuously with the aid of the guide element during the tube change. In this case, the roving between the setting agent and the sleeve is braked continuously, so that it can be wound onto the respective sleeve under a certain tensile stress. The tension can in turn be varied as described above, so that the braking effect can be adapted to the current status of the winding process.

Finally, the textile machine according to the invention is distinguished by the fact that it has a control which is designed to operate the textile machine according to one or more of the aspects described hitherto or below. In addition, it comprises a guide element which is placed between the setting means of the textile machine and a winding device and which is designed to brake the roving as it passes through the guide element. For this purpose, the guide element preferably comprises an elongated guide section which can be wrapped in the roving. There should also be a gripper that can be used to influence the number of wraps. For example, the gripper could be rotatable about an axis of rotation and comprise a gripping section in order to be able to grip the roving and to be able to wind around the guide section when the gripper is rotated.

Figuren 1 bis 3

einen Ausschnitt eines Startvorgangs an einer Textilmaschine in Form einer Luftspinnmaschine,

Figur 4

eine Draufsicht eines Ausschnitt einer Textilmaschine in Form einer Luftspinnmaschine,

Figur 5

eine Seitenansicht eines Ausschnitt einer Textilmaschine in Form einer Luftspinnmaschine,

Figur 6

die Ansicht gemäß Figur 4 mit verändertem Umschlingungswinkel,

Figur 7

eine Rückansicht eines Führungselements einer Textilmaschine in Form einer Luftspinnmaschine, und

Figuren 8 bis 10

die Ansicht gemäß Figur 4 mit jeweils verändertem Umschlingungswinkel und veränderter Stellung des Führungselements.

Further advantages of the invention are described in the following exemplary embodiments. Show it:

Figures 1 to 3

a section of a starting process on a textile machine in the form of an air spinning machine,

Figure 4

a plan view of a section of a textile machine in the form of an air spinning machine,

Figure 5

a side view of a section of a textile machine in the form of an air spinning machine,

Figure 6

the view according to Figure 4 with a different wrap angle,

Figure 7

a rear view of a guide element of a textile machine in the form of an air spinning machine, and

Figures 8 to 10

the view according to Figure 4 each with a different wrap angle and changed position of the guide element.

The Figures 1 to 3 show a schematic view of a section of a textile machine according to the invention in the form of an air spinning machine serving as an example for such a textile machine, which is used to produce a roving 1, at different times of a starting process. If required, the air spinning machine can comprise a drafting system 16 with a plurality of corresponding drafting system rollers 17 (only one of the drafting system rollers 17 is provided with a reference number for reasons of clarity), which is supplied with a fiber structure 3, for example in the form of a doubled draw frame. Furthermore, the air spinning machine shown in principle comprises a consolidation means in the form of an air spinning nozzle 2 spaced apart from the drafting device 16 with an internal swirl chamber which is known from the prior art and therefore not shown, and a yarn-forming element likewise known from the prior art and therefore not shown. In the air spinning nozzle 2, the fiber structure 3 or at least some of the fibers of the fiber structure 3 are provided with a protective twist.

Likewise, the air spinning machine can comprise a take-off unit 4 with preferably two take-off rollers 18 for the roving 1 (the take-off unit 4 is not absolutely necessary). Furthermore, there is generally a winding device 5 connected downstream of the take-off unit 4, which in turn should include at least one sleeve drive 6 and in each case one sleeve receptacle which is connected to the sleeve drive 6 and is known in principle, with the aid of which a sleeve 7 can be fixed and via the sleeve drive 6 is rotatable.

The winding device 5 can also comprise two or more sleeve receptacles, so that in addition to a receptacle for a sleeve 7, which is currently being wound during operation of the air spinning machine, one or more additional receptacles for empty sleeves 7 can be present. If the first sleeve 7 has been wound, a sleeve change takes place in which the spooled tube 7 is replaced by an empty tube 7, so that the winding process 5 can ultimately be continued without interrupting the roving production.

The air spinning machine shown as an example of a textile machine according to the invention now works according to a special air spinning process. To form the roving 1, the fiber structure 3 is guided in a transport direction T via an inlet opening (not shown) into the swirl chamber of the air spinning nozzle 2. There he receives a protective turn, i.e. H. at least some of the fibers of the fiber assembly 3 are captured by a vortex air flow that is generated by appropriately placed air nozzles. A part of the fibers is pulled out of the fiber structure 3 at least to a certain extent and wound around the tip of a yarn-forming element projecting into the swirl chamber.

Ultimately, the fibers of the fiber composite 3 are withdrawn from the swirl chamber via an inlet opening of the yarn formation element and an extraction channel arranged within the yarn formation element and adjoining the inlet opening. Finally, the free fiber ends are also pulled on a spiral path in the direction of the inlet opening and are wound as wrapping fibers around the central core fibers - resulting in a roving 1 having the desired protective twist.

Because of the only partial twisting of the fibers, the roving 1 has a warping capability, which is essential for the further processing of the roving 1 in a subsequent spinning machine, for example a ring spinning machine. Conventional air spinning devices, on the other hand, give the fiber structure 3 such a strong rotation that the necessary warping after the yarn production is no longer possible. This is also desirable in this case, since conventional air spinning machines are designed to produce a finished yarn, which is generally said to be characterized by high strength.

Before a sleeve 7 can be spooled with roving 1, a starting process must take place in which the roving 1 leaving the air spinning nozzle 2 comes into contact with the sleeve 7 brought. Part of a possible startup process is in the Figures 1 to 3 shown.

First, a fiber structure 3 is delivered into the air spinneret 2 by starting the drafting unit 16. In the air spinning nozzle 2, the roving described above takes place, in which the fiber structure 3 receives a protective rotation. Finally, the roving 1 leaves the air spinning nozzle 2 via an outlet opening (not shown in the figures mentioned) and is caught by the air flow from a suction unit 8. The suction unit 8 preferably has a suction nozzle 13 with a suction opening 9 through which air and thus also the roving 1 emerging from the air spinning nozzle 2 is sucked in or sucked in. In this in Figure 1 The stage shown thus leaves the roving 1 produced by the air spinning nozzle 2 and is sucked into the suction unit 8 via the suction opening 9, the delivery speed of the air spinning nozzle 2 preferably corresponding to the delivery speed prevailing after the starting process or being only slightly less than this.

In general, it should be noted at this point that the entire starting process is preferably without interrupting the roving manufacture or delivery, i.e. H. with active drafting device 16, active air spinneret 2 and, if present, active (i.e. pulling a roving 1 out of the air spinneret 2) take-off unit 4, so that a particularly high effectiveness of the air spinning machine shown can be guaranteed.

In addition, an indicated control 15 is provided, which is operatively connected to the described elements of the air spinning machine, in order to carry out, among other things, the starting process mentioned. The controller 15 can be present per spinning station of the air spinning machine. It is also conceivable that a controller 15 is responsible for several spinning stations.

In the next step (see Figure 2 ) the suction unit 8 is moved into a transfer position (preferably the suction nozzle 13 is pivoted about a pivot axis 14), in which the suction opening 9 and thus also a section of the roving 1 (which is still supplied by the air spinning nozzle 2) in Area of the sleeve surface is - a contact between the sleeve 7 and roving 1 exists at this stage preferably not yet.

While the suction unit 8 in Figure 2 shown position (or shortly thereafter), the traversing unit 10 in the in Figure 3 spent schematically indicated position in which the roving 1 is detected and guided by the traversing unit 10. The traversing unit 10 moves the roving 1 in the vicinity of the sleeve 7 or causes direct contact between the sleeve 7 and roving 1, so that the roving 1 (preferably under the action of corresponding rough surface sections of the sleeve 7) is gripped by the sleeve 7.

At the same time or shortly thereafter, a separation unit 11 is finally activated, which comprises, for example, a movable (preferably pivotable) separation arm 12. The separating unit 11 is brought into contact with the roving 1, preferably with the section thereof, which is located between the traversing unit 10 and the suction opening 9. at this moment there is a local braking of the roving 1 in the area which comes into contact with the separating unit 11, so that the roving 1 finally breaks between the sleeve 7 and the separating unit 11, since it continues to be wound up by the rotating sleeve 7, d. H. is subjected to a tensile force. The tearing of the roving 1 finally creates a section of the roving 1 on the suction unit side which can be removed via the suction unit 8. A roving section on the side of the air spinneret is also formed, which is already gripped by the sleeve 7 and which extends between the air spinneret 2 and the sleeve 7.

By turning the sleeve 7 further, the roving 1 still supplied by the air spinning nozzle 2 is finally wound continuously onto the sleeve 7, the traversing unit 10, by moving in the direction of the axis of rotation 24 of the sleeve 7, ensuring that the roving 1 is evenly applied to the sleeve 7 is wound up. At this stage, in which the separating unit 11 and also the suction unit 8 have assumed their original positions, the air spinning machine is finally in its normal, normal operation following the starting process, in which the sleeve 7 is rinsed with roving 1 until the desired one Coil size is reached.

According to the present invention it is now provided that the roving 1 with the aid of a Guide element 23 is guided, the guide element 23 being arranged between the air spinning nozzle 2 and the sleeve 7. The guide element 23 is preferably located between the sleeve 7 and the take-off unit 4 arranged downstream of the air spinning nozzle 2 in the transport direction T and is, for example, part of the traversing unit 10. In addition, the roving 1 is braked with the aid of the guide element 23, ie the roving 1 becomes in this way on the guide element 23 or a guide surface thereof, that the friction between the guide element 23 and the roving 1 exerts a braking effect on the roving 1.

The reason for the braking according to the invention is as follows: If the roving 1 was caught directly by the rotating sleeve 7 after passing through the air spinning nozzle 2 or a possibly downstream take-off unit 4, then a roving force would act on the roving 1, which would lead to the roving 1 breaking immediately would, since it has little tear resistance compared to a conventional yarn.

If, however, the roving 1 is guided with the aid of the guide element 23 according to the invention before it is wound onto the sleeve 7, the tensile force generated by the rotating sleeve 7 can be guided via the guide surface of the guide element 23 in contact with the roving 1 and the associated surface Friction between roving 1 and guide surface are gradually reduced. In other words, the tensile force acting on the roving 1 between the air spinning nozzle 2 and the guide element 23 is significantly smaller than between the guide element 23 and the sleeve 7. Furthermore, the guide element 23 is located on the sleeve 7 or the outer layer of the roving which has already been wound up 1 on, the roving 1 can absorb the high tensile force generated by the rotating sleeve 7 without tearing, since the fiber length of the roving 1 is generally longer than the distance between the guide element 23 and the sleeve 7 or said outer roving layer .

As a result, the roving 1 can finally be wound onto the sleeve 7 with a relatively high tensile stress without the risk of tearing the same.

A possible embodiment of the guide element 23 is shown in FIG Figures 4 and 5 . It is conceivable for the traversing unit 10 to be parallel to the axis of rotation 24 of the sleeve (s) 7 located in the winding device 5 includes a traversing arm which can be moved back and forth and which simultaneously represents the guide element 23. The guide element 23 preferably has, for example, a rod-shaped looping section 20 and a front guide section 19 for the roving 1.

Figure 4 now shows a possible course of the roving 1 coming from the air spinning nozzle 2 during the starting process, which is still sucked in by the suction unit 8 at this time. The roving 1 is guided in a guide groove 22 of the guide section 19 (cf. Figures 5 and 7 ) and loosely wraps around the wrapping section 20, so that only a slight braking force acts on the roving 1. The fact that the braking effect is not too high is crucial at this stage, since the low tensile force caused by the air flow of the suction unit 8 would not be sufficient to pull the roving 1 over the guide surface of the guide element 23 (the guide surface is in The rest of the surface of the guide element 23 which is directly in contact with the roving 1).

Before the guide element 23 is now pivoted in the direction of the sleeve 7, it can be advantageous to increase the braking effect, this being possible, for example, by rotating a gripper 21. Here, the roving 1 is grasped and further looped around the looping section 20. A corresponding "screwing in" shows the comparison of Figures 4 and 6 (which also shows that only the gripper 21, but not the guide section 19, has been moved; for this purpose, a rotational decoupling, not shown, is provided between the gripper 21 and the looping section 20 or the guide section 19, so that the gripper 21 is relative to the guide section 19 or to the looping section 20 is movable, preferably rotatable).

A view in the direction of the Figure 6 shown arrow shows Figure 7 . As can be seen from this figure, the braking effect exerted on the roving 1 by the guide element 23 arises, on the one hand, through the wrapping of the wrapping section 20. On the other hand, the braking effect is also increased by the wrapping of the looper 21, since for the amount of frictional force, the acts on the roving 1, only the wrap angle of a surface, but not its radius of curvature is decisive is. The entire wrap angle α is thus made up of the Figure 7 shown wrap angle a1 and the wrap angle in the area of the gripper 21 (and possibly further wrap angles of additional wrapped surface sections of the guide element 23) together. The actual wrap angle α in Figure 7 is therefore higher than the marked angle α1.

Figure 8 now shows the stage in which the guide element 23 rests on the sleeve 7 and thus the roving 1 is brought into contact with the sleeve 7, as shown in FIG Figure 3 is indicated (as already mentioned, the guide element 23 is preferably part of the in the Figures 1 to 3 schematically shown traversing unit 10). After the contact between the sleeve 7 and the roving 1, the roving 1 is finally cut between the sleeve 7 and the suction nozzle 13. For this purpose, the air spinning machine comprises, for example, one in the Figures 1 to 3 shown separating unit 11 with a movable, preferably pivotable, mounted separating arm 12. This is pivoted into the barrel of the roving 1 and finally causes the roving 1 to tear between the suction nozzle 13 and the sleeve 7 the other part coming from the air spinning nozzle 2 is wound onto the sleeve 7. Shows the start of the winding process Figure 9 , with the wrap angle α and thus also the braking effect on the roving 1 compared Figure 8 was further increased, this being realized by turning the gripper 21 further.

While the sleeve 7 continues to take up roving 1, the braking effect is finally increased to a final value which is maintained until the start of a subsequent sleeve change in order to be able to wind the roving 1 tightly onto the sleeve 7 under increased tension (see Figure 10 ).

If a predetermined degree of filling of the sleeve 7 is reached, the braking effect is reduced again by reducing the wrap angle α and the spooled sleeve 7 is replaced by an empty sleeve 7 without interrupting the roving production. After the roving 1 comes into contact with the last-mentioned sleeve 7, the braking effect can be increased again by increasing the wrap angle α until a new sleeve change is due.

Reference list

1

Roving

2nd

Air jet nozzle

3rd

Fiber dressing

4th

Deduction unit

5

Winding device

6

Sleeve drive

7

Sleeve

8th

Suction unit

9

Suction opening

10th

Traversing unit

11

Separation unit

12th

Separation arm

13

proboscis

14

Swivel axis of the proboscis

15

control

16

Drafting system

17th

Drafting roller

18th

Take-off roller

19th

Guide section

20th

Wrap section

21

Gripper

22

Guide groove

23

Guide element

24th

Axis of rotation of the sleeve

T

Direction of transport

α

Wrap angle

Claims (15)

1. A method for operating a textile machine which serves to produce roving (1),

   - wherein during roving production a roving (1) having a protective twist is produced by means of at least one consolidating means from a fiber bundle (3) that is fed to the consolidating means,

   - wherein the roving (1) produced by the consolidating means is wound by a winding device (5) onto a tube (7),

   - wherein the roving (1) during the winding process is guided by means of a guide element (23) which is arranged between the consolidating means and the tube (7), and

   - wherein the guide element (23) exerts a decelerating effect on the roving (1), characterized in that the decelerating effect is adapted during operation of the textile machine in such a way that it is lower during a start procedure, while the roving (1) leaving the consolidating means is being brought into contact with a tube (7), preferably an empty tube (7), and/or during a tube change, while a wound tube (7) is being replaced by an empty tube (7), than during a winding process that takes place between the start procedure and the tube change.
2. The method according to the preceding claim, characterized in that an air spinning nozzle (2) is used as the consolidating means, wherein the roving (1) having the protective twist is produced from the fiber bundle (3) within the air spinning nozzle (2) by means of a swirled air flow.
3. The method according to claim 1 or 2, characterized in that the decelerating effect is varied by decreasing or increasing the size of the contact area over which the roving (1) is in contact with the guide element (23).
4. The method according to any of the preceding claims, characterized in that the roving (1) is wrapped around the guide element (23) over a wrapping angle (a), and in that the decelerating effect is varied by varying the wrapping angle (a), for example by winding the roving (1) onto the guide element (23) or unwinding it therefrom.
5. The method according to the preceding claim, characterized in that the wrapping angle (a) during the winding process is at least temporarily between 400° and 2000°, preferably between 500° and 1800°, particularly preferably between 600° and 1600°.
6. The method according to claim 4 or 5, characterized in that the wrapping angle (a) during the start procedure and/or the tube change is at least temporarily between 50° and 1000°, preferably between 75° and 720°, particularly preferably between 100° and 500°.
7. The method according to any of the preceding claims, characterized in that, on account of the decelerating effect, a tension acts on the section of the roving (1) that is in contact with the guide element (23), wherein the decelerating effect is adapted such that the average magnitude of said tension during the winding process is at least two times, preferably at least four times, particularly preferably at least eight times, higher than during the start procedure and/or during the tube change.
8. The method according to any of the preceding claims, characterized in that the increase in the decelerating effect is increased at the latest 10 seconds, preferably at the latest 6 seconds, particularly preferably at the latest 4 seconds, after the roving (1) during the start procedure or during the tube change has entered into contact with an empty tube (7) provided by the winding device (5).
9. The method according to any of the preceding claims, characterized in that the decelerating effect is increased while a first to 600th winding, preferably while a first to 300th winding, particularly preferably while a first to 100th winding, of the roving (1) is being wound onto an empty tube (7).
10. The method according to any of the preceding claims, characterized in that the decelerating effect is reduced during the winding process at least 0.01 seconds, preferably at least 0.5 seconds, particularly preferably at least 1 second, and/or at most 20 seconds, preferably at most 10 seconds, particularly preferably at most 5 seconds, prior to the start of a pending tube change.
11. The method according to any of the preceding claims, characterized in that the roving (1), at least during the winding process, is traversed between defined turning points by the guide element (23).
12. The method according to any of the preceding claims, characterized in that the production of the roving (1) is not interrupted during the tube change, wherein during the tube change the roving (1) produced by the consolidating means is wound onto the tube (7) that was wound prior to the tube change at least until said roving comes into contact with an empty tube (7) as a result of the tube change.
13. The method according to any of the preceding claims, characterized in that the roving (1) is guided continuously by the guide element (23) during the tube change.
14. A textile machine for producing a roving (1),

    - wherein the textile machine has at least one consolidating means by which a protective twist can be given to a fiber bundle (3) that is fed to the consolidating means, and

    - wherein the textile machine has at least one winding device (5), by means of which the roving (1) can be wound onto a tube (7), by means of a guide element (23) which is arranged between the consolidating means and the tube (7), wherein the guide element (23) exerts a decelerating effect on the roving (1) characterized in that the textile machine has at least one controller which is designed to operate the textile machine according to any of the preceding claims.
15. The textile machine according to the preceding claim, characterized in that the consolidating means is designed as an air spinning nozzle (2), wherein the roving (1) having the protective twist is produced from the fiber bundle (3) within the air spinning nozzle (2) by means of a swirled air flow.

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