Spinning station for air-jet spinning machines and yarn brake for a spinning station of an air-jet spinning machine

Abstract

Spinning station (2) of a air-jet spinning machine (1), having a drafting device (3) with a supply roller pair (4) for conveying a fiber material (5) in a transport direction (T) to the spinning station (2), a spinneret (6) for producing a yarn (7) from the fiber material (5), a yarn accumulator (8) for temporarily storing a thread end (9) during a start-of-yarn operation, and a yarn brake (10) for the thread end (9), which yarn brake (10) is arranged after the supply roller pair (4) and before the spinneret (6) in the transport direction (T). Yarn brake (10) for a spinning station (2) of an air-jet spinning machine (1), comprising a movable friction section (12), which friction section can be moved from a non-use position (I) into a braking position (II), in which braking position the friction section cooperates with a friction surface (11) arranged on the spinneret (6).

Description

TECHNICAL FIELD

[0001] The invention relates to a spinning station of a air-jet spinning machine, having a drafting device with a thread supply roller pair for feeding a fiber material to the spinning station in a transport direction, a spinneret for producing a yarn from the fiber material, a yarn accumulator for temporarily storing a thread end during a start-of-yarn operation, and a yarn brake for the thread end. The invention further relates to a yarn brake for a spinning station of an air-jet spinning machine. BACKGROUND

[0002] DE 10 2004 047 580 A1 discloses such a spinning station. For restarting the start-of-yarn operation after an operating fault, that is, for example, after a thread break or a reiniger cut, the thread end from the bobbin is fed back through the spinneret against the normal fiber transport direction by means of a thread gripper up to behind the output roller pair. The thread end is fixed by the thread gripper so that it is initially pre-tensioned between the thread gripper and the output roller pair as a result of being clamped in the output roller pair. For restarting the start-of-yarn operation, the drafting device is then started again and the thread end is released by the thread gripper, as a result of which it loses the pre-tension. The thread end can therefore spring back, wind up and be further transported in this state, which can cause yarn defects in the spinneret when spinning is carried out. To prevent this, a yarn brake is arranged in the vicinity of the clamped thread of the output roller pair of the drafting device. This yarn brake is arranged in front of the output roller pair of the drafting device in the transport direction at this point. SUMMARY

[0003] The object of the invention is to further improve such a spinning station with a yarn brake.

[0004] The solution according to the invention to achieve the above object is a spinning station and a yarn brake having the features of the independent claims.

[0005] A spinning station of an air-jet spinning machine, having a drafting device with a thread supply roller pair for feeding a fiber material to the spinning station in a transport direction, a spinneret for producing a yarn from the fiber material, a yarn accumulator for temporarily storing a thread end during a start-of-yarn operation, and a yarn brake for the thread end.

[0006] The yarn brake is arranged behind the thread supply roller pair in the transport direction and in front of the spinning unit. With this arrangement, it is no longer necessary to guide the yarn against the transport direction of the fibre material into the drafting device and behind the thread supply roller pair, but only to guide the yarn from the yarn outlet side of the spinneret through the spinneret to the fibre inlet side of the spinneret. As a result, the thread supply roller pair does not have to be opened and closed, and a corresponding actuator for opening and closing the thread supply roller pair does not have to be provided. This makes it possible to save a considerable amount of expenditure on spinning machines with self-sufficient spinning stations, each of which has hitherto been provided with one such actuator. The expenditure on the control device on the spinning station is likewise significantly reduced, since the thread supply roller pair no longer has to be opened and closed in time coordination with the start-of-thread operation. As a result, it is likewise prevented that the rotational speed of the thread supply roller pair is influenced by the closure of the thread supply roller pair during the start-of-thread operation. It is also possible to generate a start-of-thread tension in the thread loop by means of the yarn brake and to maintain this start-of-thread tension throughout the start-of-thread operation. For this purpose, the thread supply roller of the drafting device is no longer required.

[0007] Furthermore, it is advantageous if the thread reservoir is arranged behind the thread supply roller pair in the transport direction and in front of the spinning unit and upstream of the yarn brake. As a result, it is possible to accommodate the thread loop directly from the spinneret in the fibre inlet side in the thread reservoir or to suck it into the thread reservoir after it has been discharged from the spinneret.

[0008] It is likewise advantageous if the yarn brake comprises a friction surface arranged on the spinning station and a friction segment movably arranged on the spinning station, which can be moved from a non-use position into a braking position, in which the friction segment cooperates with the friction surface. The friction surface is preferably arranged firmly on the spinning station. In the non-use position, the friction segment is outside the thread path or the fibre material path. As a result, the normal spinning process and the process of accommodating the thread loop in the thread reservoir for a renewed start-of-thread are not disturbed. On the basis of the movable arrangement of the friction segment, it is possible to deflect the friction segment into the thread path of the thread loop only after the thread loop has been accommodated in the thread reservoir, in order to then exert a braking force on the yarn in cooperation with the friction surface.

[0009] Correspondingly in the likewise proposed yarn brake, it is advantageous if the yarn brake has a movable friction segment, which can be moved from a non-use position into a braking position, in which the friction segment cooperates with a friction surface arranged on the spinneret.

[0010] Furthermore, it is advantageous if the friction surface arranged on the spinning station is constructed directly on the spinneret. In this way, it is not necessary to provide additional components for forming the friction surface. As a result, it is possible to further reduce the costs of a spinning machine having spinning stations configured in this way.

[0011] According to an alternative embodiment of the spinning station, however, advantageously the friction surface arranged on the spinning station is constructed on a friction plate. Preferably, the friction surface, in particular the friction plate, is arranged on the spinneret. A friction surface, preferably embodied as a friction plate, is correspondingly provided in the yarn brake, which is adapted to be arranged on the spinning station, in particular on the spinneret. The friction plate is for example matched in size to the underside of the spinneret and can for example have fastening means for fastening on the spinneret. The friction plate can for example in particular be embodied as wear-resistant or be equipped with a friction lining which improves the braking effect of the yarn brake.

[0012] Furthermore, advantageously in the spinning station and in the yarn brake, the friction surface is arranged on the spinning station or the yarn brake, in particular on the spinneret, in a removable manner. This enables the friction surface to be quickly and easily replaced in the event of wear. As a result, it is likewise possible to provide different types of friction surface, in particular friction plate, which can be used to produce different braking effects on the yarn.

[0013] Advantageously, the yarn brake has a drive, in particular a pneumatic or electric drive, for its actuation. The friction segment can be moved from the non-use position into the braking position, in which it cooperates with the friction surface, by means of the drive.

[0014] Furthermore, advantageously the braking force of the yarn brake is adjustable. This advantageously enables the spinning-in tension of the spun yarn to be matched to different conditions on the spinning station and / or to different fibre materials and to be kept at an ideal level.

[0015] According to the first embodiment of the spinning station and the yarn brake, the braking force of the yarn brake can be adjusted collectively on a plurality of yarn brakes on a plurality of spinning stations. This reduces the constructional complexity of the spinning machine.

[0016] But in particular for self-sufficient spinning stations which allow batchwise distribution, it is particularly advantageous if the braking force of the yarn brake can be individually adjusted on the spinning station. This enables both individual conditions on the spinning station and different yarn tensions which can be required for different batches to be taken into account.

[0017] For the individual adjustment of the braking force, in the spinning station and in the yarn brake, advantageously in particular the drive comprises an electromagnet. By means of such an electromagnet, the individual adjustment of the braking force can be achieved at particularly low cost.

[0018] Furthermore, in the spinning station and in the yarn brake, advantageously the friction segment is arranged on the spinning station in a removable manner. As a result, this friction segment can likewise be easily replaced in the event of wear or replaced by a friction segment with another friction effect which is enhanced or reduced.

[0019] Furthermore, it is particularly advantageous in the spinning station that the friction section is fastened to the spinning station independently of the friction surface. In this way, the friction section can be removed or replaced without the entire yarn brake having to be replaced.

[0020] Furthermore, it is advantageous in the spinning station and in the yarn brake that the yarn brake is fastened to the spinning station in a removable manner. In this way, the yarn brake can be easily provided for the spinning station of the spinning machine. It is also possible to easily remove this yarn brake without the yarn brake being required or without the arrangement of other components being impeded.

[0021] It is also advantageous that the yarn brake is fastened to the drafting device, in particular to the load or closing device of the drafting device. The yarn brake thus has good accessibility. BRIEF DESCRIPTION OF DRAWINGS

[0022] Further advantages of the application are described in the following examples. Among others:

[0023] Figure 1 schematic partial cross-sectional side view of a spinning station of a jet spinning machine,

[0024] Figure 2 schematic view of a spinning station of a spinning machine with a yarn brake during a conventional spinning operation,

[0025] Figure 3 schematic view of the spinning station during the drawing-in of the thread end into the thread reservoir after interruption of the spinning operation, Figure 2 the spinning station shown,

[0026] Figure 4 schematic view of the spinning station immediately before the renewed threading after interruption of the spinning operation, Figure 2 the spinning station shown,

[0027] Figure 5 schematic view of the spinning station during the renewed threading, Figure 2 the spinning station shown,

[0028] Figure 6 schematic view of a spinning station of a spinning machine with an alternative embodiment of a yarn brake. DETAILED DESCRIPTION

[0029] In the following description of the figures, the same reference numerals are used for the same or at least similar embodiments or figures. Some features are therefore only described at first mention or only once in connection with a suitable figure. If these features are not described again in connection with other figures, their technical teaching and / or working principle is identical with the technical teaching and working principle of the already described features of the same or similar kind. Furthermore, only one of a plurality of identical features or components in one figure is designated for the sake of clarity.

[0030] Figure 1 A schematic view of a spinning station 2 of a jet spinning machine 1 during a conventional spinning process is shown. Only a single spinning station 2 is shown here. Of course, a jet spinning machine 1 can have a plurality of such spinning stations 2 which are arranged side by side on one longitudinal side or on two mutually opposite longitudinal sides of the jet spinning machine 1. The fibre material 5 is fed to the spinning station 2 in a known manner, is drawn in a drawing device 3 and is then fed to a spinneret 6, where the fibre material 5 is spun into a yarn 7. The fibre material 5 is fed to the spinning station 2 in a transport direction T.

[0031] The drawing device 3 comprises a plurality of roller pairs in a conventional manner, the last roller pair, which is arranged at the end of the drawing device 3 in the transport direction T, being designated as a supply roller pair 4. Each roller pair comprises a driven roller, which is designated by hatching in the present figure, and a non-driven pressure roller. The pressure rollers on the input side at least can be pressed against the driven rollers by means of a common closing device 25 and be brought into a position in which they are lifted from the rollers. The closing device 25 can also be designed as a load device for generating a pressure between the roller pairs at the same time. The pressure roller of the supply roller pair 4 is designated by the numeral 15, and the driven roller of the supply roller pair 4 is designated by the numeral 16.

[0032] The spinning station 2 also comprises a take-off device 21 for taking off the yarn 7 and a winding device 26 for winding the yarn 7 onto a bobbin 20. Preferably, the yarn 7 also passes through a yarn monitor 22 before the take-off device 21, which controls the quality of the passing yarn 7 and triggers a clearing if necessary. The conventional spinning operation is thereby interrupted, and the bobbin-side yarn end 9 (see Figures 3 to 5 ) which arises as a result of this interruption has to be rethreaded. It is also possible for the yarn 7 to be torn during the spinning operation, which also requires a threading operation.

[0033] For the implementation of the spinning-in operation, the spinning station 2 has a plurality of handling components, of which only one suction nozzle 18, one thread reservoir 8 and one thread brake 10 are shown here. By means of these handling components, the spinning station 2 is able to implement the spinning-in operation itself after a production interruption without the aid of a movable maintenance device. The suction nozzle 18 and the thread reservoir 8 and, if appropriate, further handling components are subjected to a negative pressure by means of a negative pressure channel 17. For the control of all the working components and handling components, the spinning station 2 also has a control device 19, which can be connected to a superordinate machine control device. For the implementation of the spinning-in operation, the spool-side thread end 9 is guided counter to the transport direction T through the spinneret 6 and sucked into the thread reservoir 8. There, the thread end 9 is prepared for the spinning-in operation. Subsequently, the drive of the spinning station 2 is accelerated strongly and the thread end 9 is guided out in the transport direction T by means of an extraction device 21. The drafting device 3 is started and accelerated in time coordination and the end of the fibre material 5 is sucked into the spinneret 6, where the fibre material 5 is finally butt-jointed to the thread end 9 by the action of the gas stream in the spinneret 6 and thus spun in.

[0034] For this purpose, the thread end 9 is conveyed counter to the transport direction T back into the drafting device 3 in the prior art, precisely as far as behind the thread supply roller pair 4. For this purpose, actuators are required to open and close the thread supply roller pair 4, which must be controlled in time coordination with the starting of the spinning-in operation and other drives. A thread brake 10 is arranged in front of the thread supply roller pair 4 in the transport direction T, which serves to prevent the thread end 9 from sinking in and curling up.

[0035] The application proposes, in contrast, an improved spinning station 2, which is described below Figures 2-5 with reference to the drawings.

[0036] Figure 2 A part of such a spinning station 2 during a conventional spinning operation is shown schematically. There, the fibre material 5 enters the spinneret 6 in the fibre inlet 24 region, and the spun thread 7 leaves the spinneret 6 at the thread outlet 23. In this spinning station 2, the thread brake 10 is not arranged in front of the thread supply roller pair 4 in the transport direction, but behind the thread supply roller pair 4 and in front of the spinneret 6. The thread reservoir 8 is likewise arranged behind the thread supply roller pair 4 and in front of the spinneret 6 in the transport direction T. The thread reservoir 8 is arranged downstream of the thread brake 10.

[0037] In the present example, the thread brake 10 comprises a movable friction section 12, which can be moved from a non-use position I, which is shown here outside the thread path or fibre material path, into a braking position II (see Figure 5), the friction segment is active in this braking position II together with the friction surface 11. In the present example, the thread brake 10 also comprises an actuator for actuating the thread brake 10 or the friction segment 12, which can be constructed, for example, as an electromagnet 14 and which acts on a lever portion 27 to which the friction segment 12 is fastened. For the sake of replacement, the friction segment 12 can be fastened on the lever portion 27 in a removable manner. It is also possible to replace the friction segment 12 together with the lever portion 27, so that the friction segment and the lever portion are arranged in a removable manner on the spinning station 2. In the present example, the friction surface 11 is arranged on the spinneret 6 and thus on the spinning station 2 in a stable manner. Therein, it is advantageous if the friction surface 11 is arranged directly on the spinneret 6, so that the thread brake 10 has a simple construction.

[0038] The entire thread brake 10 and its components, here the electromagnet 14, the friction segment 12 and the lever portion 27, can be fastened, for example, on the closed device 25 (bottom box) of the input roller and the drafting rollers of the drafting device 3. But it is of course also possible to fasten it in the region of the thread supply roller pair 4, in particular the pressure roller 15. In this way, the thread brake 10 can be removed as a whole from the spinning station 2 or can likewise be reassembled on the spinning station 2.

[0039] Depending on the specific embodiment and type of fastening of the thread brake 10, it is advantageously possible to provide two different mirror-image embodiments of this thread brake for installation on the two longitudinal sides of the air-jet spinning machine 1.

[0040] Figure 3 It is now shown that after a production interruption, that is to say after a clearing or a thread break and before the start-up of the spinning operation, Figure 2 the spinning station is shown. Therein, the spinneret 6 is moved from the Figure 2 spinning position to the inclined start-up position in a known manner. It is now possible in this position to lead the bobbin-side thread end 9 back through the thread outlet 23 and to guide it into and through the spinneret 6 until it is discharged at the fibre inlet 24. Finally, the thread end is detected and sucked in by the pneumatic thread accumulator 8 arranged in the start-up position region of the spinneret 6. The thread end 9 is led further back until a predetermined length is stored in the pneumatic thread accumulator 8, which can be detected by a corresponding sensor (not shown). Figure 3 This situation is shown. Therein, the thread brake 10 is always in its inactive position I.

[0041] Subsequently, the thread end 9 prepared for the renewed start-up, preferably in the thread accumulator 8, is cut into sections, opened out and / or the twist in the thread end 9 is eliminated. The spinneret 6 is now deflected back into the spinning position. Figure 4 This situation is shown.

[0042] As a countermeasure to the Figure 3The described supplement or alternative to sucking in a predetermined length of yarn into the pneumatic yarn accumulator 8 can now also drive the take-off device 21 further in the transport direction T and can provide the predetermined length of the thread end 9 by the yarn 7 passing a certain point in the yarn accumulator 8, which is likewise detected by a sensor (not shown).

[0043] Figure 5 The spinning station 2 is now shown during a true end-start operation. There, the thread end 9 having a predetermined length, which is ready and stored in the yarn accumulator 8, is now accelerated by means of the take-off device 21 and is drawn off. In addition, the fiber material 5 is fed via the fiber inlet 24 to the spinneret 6 in time coordination so that it can subsequently be docked to the thread end 9 provided in the spinneret 6 and is connected to this thread end 9 by the action of the gas stream in the spinneret 6. During the end-start operation or in this phase of the drawing-off of the yarn 7, the yarn is guided by the yarn brake 10.

[0044] For this purpose, the yarn brake 10 is moved into its braking position II by means of an actuator, here an electromagnet 14, before the yarn is drawn off. In the braking position II, the friction section 12 cooperates with a friction surface 11, which is arranged directly on the spinneret 6 here. As a result, the thread end 9 is guided between the friction surface 11 on the spinneret 6 and the friction section 12 so that it remains under pretension during the entire end-start operation. In contrast to the prior art, the yarn 7 is only under pretension between the yarn accumulator 8 and the take-off device 21. Since the yarn accumulator 8 and the yarn brake 10 are arranged downstream of the thread supply roller pair 4, this pretension can be applied to the thread end 9 to be started without any influence on the thread supply roller pair 4.

[0045] As a result, the clamping force or braking force of the yarn brake 10 can also be adjusted particularly advantageously so that this yarn brake matches the conditions on the spinning station 2 and / or the fiber material 5 and / or the yarn 7. Thus, the braking force of the yarn brake 10 is also particularly advantageously adjustable. The adjustment can be carried out centrally, for example, for a plurality of yarn brakes 10 on a plurality of spinning stations 2.

[0046] But in Figures 2 to 5 In the example shown, the braking force can be adjusted individually on the spinning station 2 by means of the electromagnet 14. But even in the case of actuation by means of the electromagnet 14 of each spinning station 2, the braking force can be adjusted centrally for a plurality of spinning stations 2 by controlling the electromagnets 14 accordingly.

[0047] Once the end-start operation is completed, the thread end 9 is completely removed from the yarn accumulator 8 and the fiber material 5 is continued to be fed via the fiber inlet 24. The yarn brake 10 can now be moved back from the braking position II into the inactive position I so that the spinning station 2 is again in the Figure 2 state shown.

[0048] Finally, Figure 6 A further other embodiment of the yarn brake 10, or of the spinning station 2 with such a further other embodiment of the yarn brake 10, is shown. Unlike Figures 2-5 , the friction surface 11, which is directly and preferably firmly provided on the spinning station 2, is not arranged directly on the housing of the spinneret 6, but on a friction plate 13 which can be fastened on the spinneret 6 in a removable manner. Here, the friction plate 13 is fastened on the spinning station 2 independently of the friction section 12, so that it can be easily replaced, for example in the event of wear. Thereby, different friction plates 13 can also be provided and replaced for different purposes or different yarns 7.

[0049] Unlike the illustrated representation, the friction plate 13 does not necessarily have to be arranged on the spinneret 6, but can also be fastened on the spinning station 2 in another manner. Furthermore, the friction plate 13 can also be fastened on the spinning station 2 in a fixed manner, that is to say in a manner which cannot be easily replaced or removed, for example bonded on the spinning station.

[0050] The invention is not limited to the embodiments shown and described. Variations within the scope of the claims, and even arbitrary combinations of features shown and described in different parts of the specification or in different embodiments, are possible, as long as they do not contradict the principle of the independent claim.

[0051] List of reference signs

[0052] 1 air jet spinning machine

[0053] 2 spinning station

[0054] 3 drafting device

[0055] 4 thread supply roller pair

[0056] 5 fibre material

[0057] 6 spinneret

[0058] 7 yarn

[0059] 8 thread reservoir

[0060] 9 thread head

[0061] 10 yarn brake

[0062] 11 friction surface

[0063] 12 friction section

[0064] 13 friction plate

[0065] 14 electromagnet

[0066] 15 pressure roller

[0067] 16 driven roller

[0068] 17 negative pressure channel

[0069] 18 suction nozzle

[0070] 19 control device

[0071] 20 winding drum

[0072] 21 lead-out device

[0073] 22 yarn monitor

[0074] 23 yarn outlet

[0075] 24 fiber inlet

[0076] 25 closure device

[0077] 26 winding device

[0078] 27 stem portion

[0079] T transport direction

[0080] I inoperative position

[0081] II braking position

Claims

1. A spinning station (2) of an air-jet spinning machine (1), the spinning station comprising: a drafting device (3) having a pair of feed rollers (4) for conveying fiber material (5) in a transport direction (T) to the spinning station (2); a spinneret (6) for forming yarn (7) from the fiber material (5); a yarn storer (8) for temporarily storing yarn heads (9) during yarn head formation; and a yarn brake (10) for the yarn heads (9), characterized in that, The yarn brake (10) is arranged in the transport direction (T) after the yarn feed roller pair (4) and before the spinneret (6), and the braking force of the yarn brake (10) is adjustable.

2. The spinning station (2) according to claim 1, characterized in that, The yarn storage device (8) is arranged in the transport direction (T) after the yarn supply roller pair (4) and before the spinneret (6), and upstream of the yarn brake (10).

3. The spinning station (2) according to claim 1 or 2, characterized in that, The yarn brake (10) includes a friction surface (11) arranged on the spinning station (2) and a friction section (12) movably arranged on the spinning station (2). The friction section (12) can move from a non-use position (I) to a braking position (II). The friction section (12) works together with the friction surface (11) in the braking position.

4. The spinning station (2) according to claim 3, characterized in that, The friction surface (11) is stably arranged on the spinning station (2).

5. The spinning station (2) according to claim 3, characterized in that, The friction surface (11) arranged on the spinning station (2) is directly constructed on the spinneret (6).

6. The spinning station (2) according to claim 3, characterized in that, The friction surface (11) arranged on the spinning station (2) is formed by a friction plate (13).

7. The spinning station (2) according to claim 6, characterized in that, The friction plate (13) is arranged on the spinneret (6).

8. The spinning station (2) according to claim 1 or 2, characterized in that, The yarn brake (10) has a drive for operating it.

9. The spinning station (2) according to claim 8, characterized in that, The yarn brake (10) is a pneumatic actuator or an electric actuator.

10. The spinning station (2) according to claim 1 or 2, characterized in that, The braking force of the yarn brake (10) can be individually adjusted at the spinning station (2).

11. The spinning station (2) according to claim 8, characterized in that, The driver includes an electromagnet (14).

12. The spinning station (2) according to claim 3, characterized in that, The friction surface (11) and / or the friction section (12) are arranged in a removable manner on the spinning station (2).

13. The spinning station (2) according to claim 3, characterized in that, The friction section (12) is fastened to the spinning station (2) independently of the friction surface (11).

14. The spinning station (2) according to claim 1 or 2, characterized in that, The yarn brake (10) is removably fastened to the spinning station (2).

15. The spinning station (2) according to claim 1 or 2, characterized in that, The yarn brake (10) is fastened to the drafting device (3).

16. The spinning station (2) according to claim 15, characterized in that, The yarn brake (10) is fastened to the load device or closing device (25) of the drafting device.

17. A yarn brake (10) for a spinning station (2) of an air-jet spinning machine (1), wherein the spinning station (2) has a spinneret (6) for producing yarn (7), characterized in that, The yarn brake (10) has a movable friction section (12) that can move from a non-use position (I) to a braking position (II), wherein the friction section (12) is adapted to work in conjunction with a friction surface (11) arranged on the spinneret (6), and the braking force of the yarn brake (10) is adjustable.

18. The yarn brake (10) according to claim 17, characterized in that, The yarn brake (10) also includes a friction plate (13) as a friction surface (11), which is adapted to be arranged on the spinning station (2).

19. The yarn brake (10) according to claim 18, characterized in that, The friction surface (11) is adapted to be arranged on the spinneret (6).

20. The yarn brake (10) according to claim 17, characterized in that, The braking force of the yarn brake (10) can be individually adjusted for each yarn brake (10).

21. The yarn brake (10) according to claim 17, characterized in that, The yarn brake (10) includes an electromagnet (14) for adjusting the braking force.

22. The yarn brake (10) according to claim 17, characterized in that, The yarn brake (10) is removably fastened to the spinning station (2).

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