EP2454403B1 - Air-jet spinning apparatus - Google Patents

Description

The invention relates to an air spinning device with a spindle according to the preamble of the independent claims.

As an air-spinning device in the context of the invention, a yarn spinning device or a roving spinning device is to be understood, wherein the proposed device for all spinning processes which work with air can be used.

A spinning device which serves to produce a yarn by means of an air flow comprises a sliver feed, a drafting device, an air spinning device and a take-up device. From the sliver feeder, a sliver is fed from a fiber sliver storage presented to a drafting system. In the drafting system, the sliver is stretched under a certain delay and passed on to the air spinning device. In the air spinning device, the stretched sliver is fed via a fiber guide element of a vortex zone. The vortex zone is a space between the fiber guide element and the inlet opening in a spindle opposite the fiber guide element. The vortex zone is arranged in a nozzle body in which the fiber guide element is inserted from one side and a spindle from the opposite side. Into the vortex zone we introduce compressed air through correspondingly arranged holes, which through the arrangement of the bores leads to the formation of a vortex, which is discharged outside along the spindle. Due to the turbulence of the introduced compressed air, a part of the fibers of the introduced into the air spinning device sliver is removed from the sliver and folded around the spindle tip around. The fiber ends are trapped in the non-dissolved fibers of the sliver and are drawn into the spindle with these so-called core fibers. During the pulling of these dissolved fibers, also called Umwindefasern, in the spindle opening, the Umwindefasern be wound around the core fibers due to the vortex flow. Due to the design of the individual components and the settings of the vortex air, various properties of the spinning process can be influenced. For example, the number of wraps compared to the core fibers may be changed, or the number of wraps per length or yarn twist of the finished yarn can be adjusted. Under the yarn twist is the angle to understand under which the Umwindefasern in relation to the longitudinal axis of the yarn wrap around the core fibers. In this way, it is possible to produce yarns with different properties in the air spinning process, for example, roving. By roving is meant an intermediate which is used as a starting material for final spinning processes, such as ring spinning or rotor spinning. In the production of roving, it is important that the yarn twist on the one hand is so low that it can be dissolved in Endspinnverfahren again and on the other hand is large enough to ensure safe transport and trouble-free feeding to Endspinnvorrichtung.

Various types of air-spinning devices are known in the prior art. The EP 2 009 150 A1 discloses an air-spinning device having a nozzle body and a hollow spindle. The spindle protrudes with its spindle tip into the nozzle body. In this case, an annular discharge channel is formed between the outer surface of the spindle tip and the inner surface of the nozzle body. Through the discharge channel, the fluidizing air is discharged along the spindle. The discharge channel has a cylindrical shape and the distance between the inner surface of the nozzle body and the outer surface of the spindle is constant. This gap width is constant over the course of the spindle longitudinal axis, whereby the cross-sectional area normal to the longitudinal axis of the spindle is constant over the course of the longitudinal axis of the spindle. In addition, by the EP 2 009 150 A1 discloses a specific range for the dimension of the gap width and the inner diameter of the nozzle body. Apart from the dimensions of the spindle tip and the nozzle body and thus the definition of the discharge channel, the shape of the discharge channel is crucial for the behavior of the vortex air flow. Due to the cylindrical shape of the discharge channel, the fluidizing air can flow unhindered along the spindle tip. In this case, short fibers are detected by the flow and carried away from the spindle tip of the outflowing air. This creates a so-called outflow, which contains fibers that were due to the process not involved in the formed yarn and excrete from the spinning process. The amount of waste thereby significantly affects the manufacturing costs of a yarn by reducing the utilization of raw materials. A disadvantage of the disclosed air spinning device is also that the yarn twisting can be influenced only by a reduction in the swirling air, with the result that a reduction of the swirling air at the same time leads to a reduction in the number of the Umwindefasern, while the amount of waste usually increases, since the fibers are bad integrated.

The object of the invention is to avoid the disadvantages of the prior art and to provide an air spinning device which allows minimization of the departure and thus a better utilization of raw materials and simplifies adjustment of the yarn rotation.

The object is achieved by an air spinning device with the characterizing features of the independent claims. The object is achieved in that an air spinning device is provided with a nozzle body and a hollow spindle with a spindle tip and a longitudinal axis, wherein the spindle tip protrudes into the nozzle body and between a outer surface of the spindle tip and an inner surface of the nozzle body, a drain channel with an annular cross-sectional area forms and a normal to the longitudinal axis of the spindle seen gap width at a certain point of the discharge channel over the circumference of the spindle is constant. In this case, the outer surface of the spindle tip and / or the inner surface of the nozzle body is shaped such that in the discharge channel in its course in the direction of the longitudinal axis of the spindle at least two bottlenecks in the discharge channel is formed, the discharge channel in its course in the direction of the longitudinal axis of the spindle each of these constrictions has an annular cross-sectional area that is smaller than the annular cross-sectional area of the bleed passage before and after each of these at least two constrictions.

The invention is basically applicable to any air-spinning machine, irrespective of the type of yarn or roving to be produced, in which at least part of the fibers in the cross-section of the process product has a rotation and the machine therefore has an air-spinning device with a hollow spindle and a nozzle body.

In air spinning for making a yarn or roving by wrapping core fibers with wraps, air spinning devices are used which comprise a hollow guide spindle and a nozzle body. In the spindle a Garnführungskanal is provided, which opens with a spindle opening in the spindle tip. A fiber sliver to be spun is introduced into the nozzle body via a fiber guide element arranged upstream of the spindle. The spindle protrudes with its tip into the nozzle body, wherein a discharge channel with an annular cross-sectional area forms between an outer surface of the spindle tip and an inner surface of the nozzle body. Between the fiber guide element and the spindle tip, a vortex zone is formed. By appropriately arranged holes compressed air is injected into the vortex zone, which results in a vortex flow due to the arrangement of the holes. The compressed air is removed from the vortex zone via the discharge channel, resulting in a rotating air flow along the spindle. The fibers introduced into the air-spinning device by the fiber guiding element are divided by the turbulent flow into core fibers, sheath fibers and fibers, the core fibers being introduced directly into the spindle opening, the sheath fibers being trapped at one end in the core fibers and transferred at the other end via the spindle tip and the outlet is discharged from the air spinning device through the airflow passing the spindle. The fibers placed around the spindle tip move helically around the spindle tip and form a so-called fiber sun. The spindle tip is that region of the spindle in which the transferred fibers move. The removal of air beyond this area of the spindle has no direct influence on the movement of the fibers. The number of Umwindefasern is determined by the distance of the spindle tip of a last terminal point of the sliver. The sliver is passed before reaching the fiber guide element by a pair of rollers which forms a terminal point. Due to the length of the individual fibers, the distance between this clamping point and the spindle tip is selected. With a constant fiber length, the proportion of Umwindefasern increases with an increase in the distance between the clamping point and the spindle tip. However, this increase in the number of Umwindefasern simultaneously causes an increase in the departure. By a. Narrowing of the discharge channel, the outlet can be reduced again, but this has a detrimental effect on the turbulence of Umwindefasern.

According to the invention, the drainage channel is designed in its geometric shape such that fibers located at the exit are caught by the wraparound fibers prior to deployment and introduced into the yarn or roving. This has the advantage that the finish is reduced without affecting the turbulence of the Umwindefasern. The shape of the discharge channel changes the circulation of the fibers around the spindle tip. Viewed along the length of the fibers, individual sections of the fibers are subject to accelerations, decelerations or swirls in their rotating helical motion due to the design of the bleed channel. The nature of the movements made by the fibers around the spindle tip also affects the yarn twist. By reducing the rotational speed results in a lower rotation, the air and flow conditions in the vortex zone must not be changed, for example by reducing the fluidizing air.

In a first embodiment, the air spinning device comprises a nozzle body and a hollow spindle with a spindle tip and a longitudinal axis, wherein the spindle tip protrudes into the nozzle body and forms an outlet channel with an annular cross-sectional area between an outer surface of the spindle tip and an inner surface of the nozzle body. A gap width seen normal to the longitudinal axis of the spindle at a certain point of the discharge channel is constant over the circumference of the spindle. The outer surface of the spindle tip is shaped such that in the discharge channel in its course in the direction of the longitudinal axis of the spindle at least two bottlenecks are formed, wherein the discharge channel in its course in the direction of the longitudinal axis of the spindle at each of these bottlenecks has an annular cross-sectional area, the smaller is as the annular cross-sectional area of the discharge channel before and after each of these at least two bottlenecks. The inner surface of the nozzle body is cylindrically shaped, so that over the circumference of the spindle at each point of the discharge channel results in the same gap width and an annular cross section is formed. Through the bottlenecks created in the discharge channel, the flow pattern of the flowing fluidized air is influenced. The bottlenecks produce a change in the turbulence the outflowing air. The speed of the outflowing air is influenced by the bottlenecks. The speed is reduced before a constriction, increased by the narrowing of the discharge channel and reduced again by the subsequent expansion of the discharge channel. By creating a tear-off edge due to the shape at the throat, backflows or vortices that normally rotate with the air flow along the spindle can be created, which also contributes to the reduction of the outlet.

The formation of backflow to a bottleneck is enhanced by a second subsequent bottleneck. The backflow and the resulting vortex cause the fibers, which are normally discharged along the spindle, to be at least partially pressed against the spindle. Near the spindle outer surface, these fibers are caught by the fibers in the fiber sun and incorporated into the yarn. The vortexes created by the backflows rotate about an axis which is substantially perpendicular to the axis of the spindle and is located on a circle concentric with the inner contour of the nozzle body. The vortex turns on the one hand in itself and on the other hand, the vortex is circular, rotated by the fiber sun rotating air flow to the spindle.

The formation of a constriction can be effected by providing an annular bead on the outer surface of the spindle tip. The formation of the bead is limited in its geometric form only in that the said cross-sectional area over the circumference of the spindle results in a uniform gap width. The molded bead can be round, wavy, or even have edges. In a design with multiple bottlenecks, these can be formed by a plurality of beads, wherein the beads can differ by different geometric shapes as well as different dimensions.

To promote the formation of the return flows, respectively the eddy currents normal to the spindle axis, asymmetrical waveforms or beads, respectively bulges, which are provided in the direction of the yarn course with an undercut, are suitable, for example.

Preferably, the spindle is designed in two parts. In this case, the spindle tip forms with the bead formed thereon a first part of the spindle and can be attached to the second part of the spindle. Under attachable is to be understood that the first and the second part of the spindle are precisely matched to one another at a contact point. The parts of the spindle can be assembled without the creation of a mechanical or chemical compound at the contact point. Due to the pressure conditions prevailing in the nozzle body, the two parts of the spindle are held together. Further, a mechanical connection of the first with the second part of the spindle can be provided, this may for example be a plug or screw connection. In a further embodiment, the first part of the spindle is formed by the outer surface of the spindle tip, which can be attached to the second part of the spindle, for example in the form of a spindle tip sleeve. The attachment can be done by attaching or another type of attachment, such as screws. The advantage of the two-part design lies in a simple interchangeability of the part of a spindle which is subjected to the greatest wear. In addition, there is the possibility of changing the shape of the outer surface of the spindle tip, without having to replace the entire spindle. Simultaneously with the replacement of the spindle tip a change in the vortex zone is possible if the spindle tip, for example, extends deeper into the nozzle body than the replaced spindle tip.

It has been shown that, for the structural design of the bead or the sum of the beads, a ratio of a maximum outside diameter of the bead to a smallest outside diameter of the spindle tip is preferably 1.05 to 1.5.

In a second embodiment, the spindle tip is formed in a cylindrical shape and the inner surface of the nozzle body is formed such that in the discharge channel in its course in the direction of the longitudinal axis of the spindle at least two bottlenecks are formed, wherein the discharge channel in its course in the direction of the longitudinal axis of the spindle at each of these constrictions has an annular cross-sectional area which is smaller than the annular cross-sectional area of the discharge passage before and after each of these at least two bottlenecks. The constriction can be formed by a bulge in the nozzle body, which projects annularly into the interior of the nozzle body. Also for the execution of such a bulge various geometric shapes are conceivable. The formed bulge may be round or have edges. In a design with multiple bottlenecks, these can be formed by a plurality of protrusions, wherein the bulges can differ by different geometric shapes as well as different dimensions. The nozzle body can also be designed in two parts, wherein the inner surface of the nozzle body is formed by a nozzle body insert and this can be introduced into the nozzle body.

By changing the position of the nozzle body to the spindle in the direction of the longitudinal axis of the spindle, the formation and the size of bottlenecks within the discharge channel can be adjusted. Characterized in that the spindle or the nozzle body is movable in the direction of the longitudinal axis of the spindle, the discharge channel is adjustable in shape along the spindle tip. By a moving in the longitudinal axis of the spindle nozzle body, the same effect is achieved because the relative displacement of the spindle and nozzle body against each other leads to a change in the setting. Thus, for example, an enlargement of the distance between the spindle and the spindle opening of the fiber guide element can be used to increase the vortex zone. At the same time, the gap width can be reduced, if beads located on the spindle tip are brought into conformity with bulges attached to the inner surface of the nozzle body. The same settings can be achieved by replacing a spindle tip sleeve or a nozzle body insert.

A combination of the first with the second embodiment is conceivable. However, the design of the inner surface of the nozzle body and the outer surface of the spindle are so matched to one another that the cross-sectional area of the discharge channel is annular and results in a certain cross-sectional area a gap width, which is equal over the circumference of the spindle. A further embodiment can be achieved if the bulges in the nozzle body do not reduce the inner diameter of the nozzle body, but increase it. Also such grooves or grooves are Under the term bulges to understand, provided in conjunction with the spindle tip a bottleneck of the discharge channel.

Regardless of the design of the discharge channel can be changed by the use of a Garnführungseinses in the yarn guide channel of the spindle tip, the inner diameter of Garnführungskanals. At the same time by such Garnführungseinsatz the shape of the spindle opening can be changed. Through the creation of bottlenecks in the discharge channel, a backflow can form in the yarn guide channel, which leads to air being sucked against the yarn conveying direction by the spindle into the vortex zone. Accordingly, the air flow which is sucked along the fiber guide element in the vortex zone decreases. The air flowing along the fiber guiding element is important for the sliver dissolution and the transport of the sliver to the spindle opening. This circumstance can be taken into account by narrowing the yarn guide channel with the use of a Garnführungseinsatzes in the spindle tip.

Figur 1

Schematische Darstellung einer Luftspinnvorrichtung nach dem Stand der Technik

Figur 2

Schematische Darstellung einer erfindungsgemässen Luftspinnvorrichtung in einer ersten Ausführungsform

Figur 3

Schematische Darstellung einer erfindungsgemässen Luftspinnvorrichtung in einer zweiten Ausführungsform

Figur 4

Schematische Darstellung einer erfindungsgemässen Luftspinnvorrichtung in einer dritten Ausführungsform

Figur 5

Schematische Darstellung einer zweiteiligen Spindelspitze

Figur 4

Schematische Darstellung einer erfindungsgemässen Luftspinnvorrichtung in einer vierten Ausführungsform

Figur 7

Schematische Darstellung einer zweiteiligen Spindel

Figur 8

Schematische Darstellung verschiedener Ausführungsformen einer Spindel

Figur 9

Schematische Darstellung verschiedener beispielhafter Formen von Ausbuchtungen respektive Wülsten an Düsenkörper oder Spindel

In the following the invention will be explained with reference to exemplary embodiments and explained by drawings:

FIG. 1

Schematic representation of an air-spun device according to the prior art

FIG. 2

Schematic representation of an inventive air spinning device in a first embodiment

FIG. 3

Schematic representation of an inventive air spinning device in a second embodiment

FIG. 4

Schematic representation of an inventive air spinning device in a third embodiment

FIG. 5

Schematic representation of a two-part spindle tip

FIG. 4

Schematic representation of an inventive air spinning device in a fourth embodiment

FIG. 7

Schematic representation of a two-part spindle

FIG. 8

Schematic representation of various embodiments of a spindle

FIG. 9

Schematic representation of various exemplary forms of bulges respectively beads on nozzle body or spindle

FIG. 1 shows a schematic representation of an air spinning device 1 with a nozzle body 2, a spindle 3, a fiber guide element 4 and a pair of rollers 5. The spindle 3 is hollow and comprises a Garnführungskanal 6 which opens into a spindle opening 9 at the spindle tip 8. Through the pair of rollers 5, a sliver 14 is fed via a fiber guide element 4 of the spindle opening 9. Through holes 20 air is introduced in the direction of the spindle tip 8 in the nozzle body 2. The bores are arranged in such a way that a vortex flow results at the spindle tip 8, which detects a part of the fibers from the sliver and moves over the spindle tip 8. The introduced air is discharged via a discharge channel 13 of the spindle tip 8 along, wherein the air flow moves around the spindle tip 8 around. The discharge channel 13 is formed by the outer surface 11 of the spindle tip 8 and the inner surface 12 of the nozzle body 2. The discharge channel 13 has due to the geometry of the spindle tip 8 and the interior of the nozzle body 2 has an annular cross-section. The annular cross section has a constant gap width S around the spindle tip 8 normal to the longitudinal axis 7 of the spindle 3. The fibers 10 placed around the spindle tip 8 are moved helically about the spindle tip 8 by the rotating air flow. The spindle tip 8 is that part of the spindle 3, around which the folded fibers 10 rotate. The removal of the air beyond this region of the spindle 3 no longer has any direct influence on the movement of the fibers 10. The second end of the fibers 10 is caught in the core fibers, which pass directly into the spindle opening 9 from the fiber guiding element 4. Thereby, the folded fibers 10 are drawn into the spindle opening 9, whereby they wind around the core fibers due to the rotating air flow. The distance L between the pair of rollers 5 and the spindle tip 8 and the spindle opening 9 has a significant influence on the number of Umwindefasern 10 which are formed by the fluidized air.

FIG. 2 shows a section of a nozzle body 2 with a projecting into the nozzle body 2 spindle 3 with a spindle tip 8. Normal to the longitudinal axis 7 of Spindle 3 and spindle tip 8 are a plurality of annular beads 15 formed on the spindle tip 8. The beads 15 shown are shown by way of example with a symmetrical round shape. However, it is also possible to choose angular shapes, and a symmetrical arrangement is not mandatory. The limited by the inner surface 12 of the nozzle body 2 and the outer surface 11 of the spindle tip 8 discharge channel 13 has an annular cross-section. By the beads 15, the discharge channel 13 in its course along the longitudinal axis 7 of the spindle 3 more bottlenecks. The gap width S is smaller at these bottlenecks than in each case before or after a bead 15.The air flow moving helically in the discharge channel 13 in the direction of the longitudinal axis 7 is influenced by the bottlenecks.

FIG. 3 shows a further embodiment of the air-spinning device according to the invention. The nozzle body 2 is different from FIG. 2 formed in two parts, wherein the discharge channel 13 is limited by the inner surface of a nozzle body insert 17. The use of a nozzle body insert 17 allows easy replacement of a highly stressed component without having to change the entire nozzle body 2. It is also possible in the same nozzle body 2 different nozzle body inserts 17 to install alternately. In the exemplary embodiment shown, the spindle tip 8 is cylindrical with a flat surface. The inside of the nozzle body 17 is provided with trapezoidal bulges 16 which project annularly into the interior of the nozzle body insert 17. Through the bulges 16 13 bottlenecks are created in the discharge channel. The trapezoidal shape of the bulges causes the air flow at the edge projecting into the discharge channel 13 to break off and form vortices whose axis of rotation is approximately normal to the longitudinal axis 7 of the spindle 3.

FIG. 4 shows a combination of the embodiments of FIGS. 2 and 3 , In Ablasskanal 13 are created by annular bulges 16 in the nozzle body insert 17 and by annular beads 15 at the spindle tip bottlenecks. The beads 15 and the bulges 16 need not be attached to the same stiffness in the course of the longitudinal axis 7 of the spindle 3. In addition, the spindle 3 is arranged displaceably in its holder relative to the nozzle body 2. The spindle 3 can in the direction D the longitudinal axis 7 of the spindle to be moved. The adjustment of the position of the spindle tip 8 within the nozzle body insert 17 allows a variation of the conditions in the discharge channel 13 which influence the air flow along the spindle tip 8. The departure behavior of the air spinning device can be adjusted to the properties and composition of the fiber slivers to be spinned by changing the flow conditions in the discharge channel, without having to replace spindle tip 8 or nozzle body insert 17.

FIG. 5 shows the embodiment of the FIG. 2 with a two-part spindle 3. About the spindle tip 8 a spindle tip sleeve 18 is attached. The beads 15 which create the bottlenecks in the discharge channel are not directly mounted on the spindle tip 8 in the illustrated two-part embodiment of the spindle 3, but on the outer surface of a spindle tip sleeve 18. The spindle tip sleeve 18 is easily interchangeable as a wear part. In an exchange of the spindle tip sleeve 18, however, it is also possible to choose a spindle tip sleeve 18, which has a different design of the annular beads 15 on its outer side. In the embodiment shown, the spindle tip sleeve is attached to the spindle tip 8. Due to the air currents in the discharge channel no further connection between the spindle tip 8 and spindle tip sleeve 18 is necessary. However, the spindle tips sleeve can also be attached by other fastening methods on the spindle tip 8, for example by a screw, a pressing or gluing method, a positive connection, a snap connection or by magnetic forces.

FIG. 6 also shows the embodiment of the FIG. 2 wherein additionally on the inside 12 of the nozzle body 2 bulges 16 were introduced. The projecting into the interior of the nozzle body 2 bulges 16 are formed in the form of rings with a rectangular cross-section. In cooperation of the bulges 16 with the provided on the spindle tip 8 beads 15 creates a discharge channel 13 in the form of a labyrinth. FIG. 6 also shows that the bottlenecks created by beads 15 and bulges 16 in the discharge channel 13 may have a small extension in the direction of the longitudinal axis 7 of the spindle 3 in relation to the length of the spindle tip 8. The built-in rings are shown schematically, one Design of fluidically favorable embodiments of beads 15 and bulges 16 is carried out by the person skilled in the art and is not taken into account in the illustration.

FIG. 7 also shows the embodiment of the FIG. 2 In addition, a Garnführungseinsatz 19 is shown. The inner diameter of a spindle 3, or the dimensions of the Garnführungskanals 6 a spindle 3 is dependent on various factors, such as the properties and composition of the fiber material to be spinned or the desired yarn quality or the rotation of the yarn to be produced. By changing the shape of the discharge channel 13 and thus the air flow of the fluidizing air flowing out of the vortex zone, a further size influencing the dimensions of the yarn guide channel 6 has been added. Since the design of the discharge channel 13 can be additionally influenced by the use of spindle tip sleeves, nozzle body inserts or the change in the position of the spindle tip 8 in the nozzle body, a simple adjustment of the dimensions of the Garnführungskanals 6 is advantageous. Such adjustment is possible through the use of Garnführungseinsätzen 19. A yarn guide insert 19 is inserted through the spindle opening in the yarn guide channel 6 of the spindle 3. The positioning of the Garnführungseinsatzes 19 in Garnführungskanal 6 can be done by a simple stop 21. Such a stop 21 may for example be formed on the spindle 3 or formed by a Seeger ring used.

FIG. 8 shows various embodiments of a design of the spindle tip 8 according to the invention. The four spindle tips 8 shown are arbitrary with the in the FIGS. 2 to 6 shown configurations of the inner surfaces of the nozzle body respectively nozzle body inserts can be combined to form a discharge channel. The four illustrated spindle tips 8 have various annular beads 15 formed. However, the beads 15 can also by Spindelspitzenhülsen after the FIG. 5 be formed. In the illustrated examples, in each case a bead 15 is arranged in the vicinity of the spindle opening 9, it being noted that immediately at the location of the spindle opening 9, the outer diameter of the spindle tip is smaller than at the point the largest extent of the annular bead 15. As a result, a bottleneck is not formed directly on the spindle opening 9 in the air spinning device.

FIG. 9 shows a schematic representation of various exemplary forms of bulges respectively beads on the inner surfaces of the nozzle body or the outer surfaces of the spindle tips. In the FIGS. 9A to 9D is in each case indicated by the arrow 23, the Garnlaufrichtung. Under the Garnlaufrichtung is that direction to understand in which the yarn during operation through the Garnführungskanal along the longitudinal axis 7 of the spindle runs.

FIGS. 9A and 9C show detail sections of the spindle tips. 8 Figure 9A shows a spindle tip 8 with a longitudinal axis 7 and a molded bead 15. The bead 15 is formed in a symmetrical shape like a wave. In this case, in symmetrical design, the Garnlaufrichtung 23 plays no role. In FIG. 9C In contrast, a bead 15 is shown with an undercut 22. In this case, the yarn running direction 23 is important, since the desired backflow with the vortex formation does not occur to the desired extent on flow of the bead from the wrong side.

FIGS. 9B and 9D show detail sections of the nozzle body 2 in a sectional view, so that the inner surface 12 of the nozzle body 2 can be seen. FIG. 9B shows a nozzle body 2 with an asymmetric bulge 16. The bulge 16 is in the yarn running direction 23 first rising obliquely to then drop steeply. Such an arrangement promotes the formation of a backflow to aid in the incorporation of short fibers into the forming yarn in the spindle tip. FIG. 9D shows a nozzle body 2 with two consecutive edged bulges 16th

In FIG. 9D Both bulges 16 are the same, which is not mandatory. Through the undercut 22, the formation of the return flow 24 and a resulting vortex is promoted. Through the return flow 24 are short fibers located in the exit, which are conveyed across the bulge 16 away in the direction of the center of the nozzle body 2 away from the inner surface 12 of the nozzle body 2 moves. In this center of the nozzle body 2 is the spindle tip with the rotating fiber sun.

Legend

1

Air spinning device

2

nozzle body

3

spindle

4

Fiber guide element

5

roller pair

6

yarn guide

7

Longitudinal axis of the spindle

8th

stem tip

9

spindle hole

10

fiber

11

Outer surface of the spindle tip

12

Inner surface of the nozzle body

13

drain channel

14

sliver

15

bead

16

bulge

17

Nozzle body use

18

Spindle tip sleeve

19

Garnführungseinsatz

20

drilling

21

attack

22

undercut

23

yarn running

24

backwash

D

Movement of the spindle

S

gap width

L

Distance between roller pair and spindle tip

Claims (14)

1. Air spinning device (1) having a nozzle body (2) and a hollow spindle (3) with a spindle tip (8) and a longitudinal axis (7), wherein the spindle tip (8) protrudes into the nozzle body (2) and an outlet channel (13) having a ring-shaped cross-sectional area is formed between an outside surface (11) of the spindle tip (8) and an inside surface (12) of the nozzle body (2), and a gap width (S) at a certain location of the outlet channel (13) as seen normal to the longitudinal axis (7) of the spindle (3) is constant over the circumference of the spindle (3), characterized in that the outside surface (11) of the spindle tip (8) and/or the inside surface (92) of the nozzle body (2) is/are shaped in such a way that at least two constrictions are formed in the outlet channel (13) and its course in the direction of the longitudinal axis (7) of the spindle (3), wherein the outlet channel (13) has a ring-shaped cross-sectional area at each of these constrictions in its course in the direction of the longitudinal axis (7) of the spindle (3), this cross-sectional area being smaller than the ring-shaped cross-sectional area of the outlet channel (13) upstream and downstream from each of these at least two constrictions.
2. The air spinning device (1) according to Claim 1, characterized in that at least one ring-shaped bulge (15) is provided on the outside surface (11) of the spindle tip (8).
3. The air spinning device (1) according to Claim 1 or 2, characterized in that at least one ring-shaped barreling (16) protruding into the interior is provided on the inside surface (12) of the nozzle body (2).
4. The air spinning device (1) according to any ona of Claims 1 to 3, characterized in that the spindle (3) is designed in two parts, wherein the spindle tip (8) is a first part of the spindle and is attachable to the second part of the spindle.
5. The air spinning device (1) according to any one of Claims 1 to 3, characterized in that the spindle (3) is designed in two parts, wherein the outside surface (11) of the spindle tip (8) is formed by a spindle tip sleeve (18) which is attachable to the spindle tip (8).
6. The air spinning device (1) according to any one of Claims 1 to 5, characterized in that the nozzle body (2) is designed in two parts, wherein the inside surface (12) of the nozzle body (2) is formed by a nozzle body insert (17) which can be introduced into the nozzle body (2).
7. The air spinning device (1) according to any one of Claims 1 to 6, characterized in that spindle (3) or the nozzle body (2) can be moved in the direction (D) of the longitudinal axis (7) of the spindle (3) so that the outlet channel (13) is adjustable in shape along the spindle tip (8).
8. A method for producing a yarn or a roving by winding core fibers with winding fibers using an air spinning device (1) wherein the air spinning device (1) comprises a hollow spindle (3) having a spindle tip (8) and a spindle opening (9), a nozzle body (2) and a fiber guide element (4), the spindle (3) protrudes with its spindle tip (8) into the nozzle body (2) and an outlet channel (13) with a ring-shaped cross-sectional area is formed between an outside surface (11) of the spindle tip (8) and an inside surface (12) of the nozzle body (2), and the fibers introduced into the air spinning device (1) by the fiber guide element (4) are divided by an eddy current into core fibers, winding fibers and discharge, such that the core fibers are introduced directly into a spindle opening, the winding fibers are captured by one end in the core fibers and at another end are wrapped around the spindle tip (8) and the discharge is removed from the air spinning device by a stream of air guided along the spindle (3), characterized in that the outlet channel (13) is shaped in such a way that fibers in the discharge are captured by the winding fibers before being discharged and are introduced into the yarn or roving, such that at least two constrictions are formed in the outlet channel (13) in its course in the direction of a longitudinal axis (7) of the spindle (3) and at each of these constrictions, a ring-shaped cross-sectional area, which is smaller than the ring-shaped crosssectional area of the outlet channel (13) upstream and downstream from each of these at least two constrictions are formed.
9. The method according to Claim 8, characterized in that the air flow through the outlet channel is influenced in such a way that eddy currents are formed in a direction normal to the air flow along the spindle (3).
10. A spindle (3) for use in an air spinning device (1) according to any one of Claims 1 to 6 having a yarn guide channel (6) and a spindle tip (8), such that the yarn guide channel (6) opens in a spindle opening (9) in the spindle tip (8), characterized in that the spindle tip (8) is provided with at least one bulge (15).
11. The spindle (3) according to Claim 10, characterized in that the ratio of the largest outside diameter (A) of the bulge (15) to the smallest outside diameter (B) of the spindle tip (8) is 1.05 to 1.5.
12. The spindle (3) according to Claim 10 or 11, characterized in that the spindle (3) is formed in two parts and a first part of the spindle is formed by the spindle tip (8).
13. The spindle (3) according to Claim 10 or 11, characterized in that the spindle (3) is in two parts and a first part of the spindle is formed by a spindle tip sleeve (18) attachable to the spindle (3), at least one bulge (14) being integrally molded on the spindle tip sleeve (18).
14. The spindle (3) according to any one of Claims 10 to 13, characterized in that a yarn guide insert (19) can be introduced into the spindle (3) and the spindle opening (9) and/or the yarn guide channel (6) can thereby be altered in dimension and shape.

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