EP2578730B1 - Thread creation element for a spinning position of an air jet spinning machine with a twist stop element - Google Patents

Description

The present invention relates to a yarn-forming element for a spinning station of an air-spinning machine, wherein the yarn-forming element has an inlet opening on one end side as well as a discharge channel for a yarn beginning in the region of the inlet opening and extending along a longitudinal axis within the yarn formation element.

Yarn-forming elements are known from the prior art and are placed in the air-spinning machine in a so-called vortex chamber. Into the vortex chamber is introduced, usually with the help of a delivery roller pair, a stretched or evened fiber material via a yarn guide element and exposed to a tangential vortex air flow. Finally, this air flow causes the outer fiber ends of the fiber material in the region of the inlet opening of the yarn-forming element to wind around the non-twisted core fibers and permanently enclose them. The yarn produced in this way is finally withdrawn via the discharge channel from the spinning station and wound, for example, on a spool.

In order to avoid transmission of the torque exerted by the air flow on the outer fibers (the air is introduced tangentially to the inlet opening) as far as possible on the untwisted core fibers, the diameter of the inlet opening is usually chosen to be very small. That's what they call WO 2006/017 948 A1 For example, an inlet opening diameter of 0.8 mm to 1.2 mm.

DE-A-3714213 shows another prior art.

Even in this case, however, a - albeit small - torque transmission from the Umwindefasern on the core fibers can not be excluded. This can eventually lead to a so-called false-wire formation of the Core fibers and thus the entire yarn come. However, since the false-twisted wire has the same direction of rotation as the binder fibers due to the torque, a reverse rotation of the fibers occurs during the dissolution of the false-twisted wire and thus a certain loosening of the fiber dressing or a loss of strength of the produced yarn.

The object of the invention is to avoid the mentioned disadvantages of the prior art.

The object is achieved by a yarn formation element having the features of patent claim 1.

According to the invention, it is proposed that the yarn-forming element has at least one swirl-stop element which at least partially narrows the cross-section of the take-off channel within the take-off channel. In other words, an element or a profiling of the withdrawal channel bounding inner wall of the Garnbildelements is present, which protrudes into the discharge channel and thus provides a contact surface for the produced and withdrawn via the discharge duct yarn available. The extraction channel thus does not have exclusively the known from the prior art form of a cylindrical or frusto-conical bore. Rather, it has one or more spin stop elements in the form of indentations, elevations, bulges, folds or other profilings, which cause the inner wall of the discharge channel has a shape that deviates from the shape of a cylinder or truncated cone.

Finally, unlike a cylindrical or frusto-conical inner wall, the twist stop elements constitute an obstacle which counteracts false-wire formation, in particular of the core fibers. If these begin to rotate in the region of the inlet opening and with them the subsequent yarn, the yarn inevitably assumes a somewhat curved, ie deviating from a straight line, longitudinal extent. in this connection it comes in contact with the inner wall and thus also the spin stop element. Finally, the friction present between the yarn and the twist stop element effectively prevents the formation or continuation of the rotation and thus the formation of a false twisting wire. As a result, the yarn passes through the trigger channel without significant false rotation.

In this context, the inner wall of the exhaust duct in the region of the swirl stop element in a cross section running perpendicular to the longitudinal axis assumes a course which deviates from the course of a circle extending concentrically to the longitudinal axis. In any case, the discharge channel in the region of the or the swirl stop elements on a contour which differs from the contour of a cylindrical or frusto-conical bore. It is not excluded that a certain peripheral portion of the take-off channel in the area of the twist stop elements takes a circular arc course. In between, however, are one or more projections, which protrude from an imaginary circular shape radially into the interior of the flue and thus an obstacle to the propagation of a yarn balloon (in the false twisting around a central axis of the flue and moving to the inner wall in contact coming section of the Yarns).

It when the Garnbildungselement has a plurality of spin stop elements, which are formed by elevations of the inner wall is particularly advantageous. The elevations may be designed knob-shaped, wedge-shaped, rectilinear or curved and cause the inner wall has a surface structure that differs from a smooth wall. For example, the inner wall could also have a relatively large roughness (> RA 0.5), so that the inner wall has a plurality of roughness-causing elevations. In general, it should also be pointed out at this point that the spin stop element or elements can be arranged directly in the region of the withdrawal channel which adjoins the inlet opening. Also conceivable is a certain Distance between inlet opening and swirl stop element (s), wherein the distance, for example, an amount of 1 mm to 20 mm, preferably 1 mm to 10 mm, may have.

Also, it is extremely advantageous if the swirl stop element is formed by a web which extends axially to the longitudinal axis of the discharge channel and extends in the radial direction with respect to the longitudinal axis in the discharge channel. In a cross-section of the discharge channel in the region of the swirl or the baffles created in this way a kind of sprocket with inwardly directed teeth, the individual teeth form the twist stop elements, which extend from an imaginary circular inner wall radially into the interior of the discharge channel. The formation of a yarn balloon to be found in the false-twist formation, and thus also false-twisting itself, is thus prevented since it is no longer possible to swing or slightly turn the slightly curved yarn about a central axis of the discharge channel. The webs may have a flat or even a pointed or bevelled surface on their projecting into the interior of the discharge duct side. The radial extent of the webs is also advantageously 0.1 mm to 2 mm. Alternatively, the amount of said extension can also be selected as a function of the inlet opening diameter. For example, a radial extent, the amount of which corresponds to 1/10 to 1/3 of the inlet opening diameter would be advantageous.

Furthermore, it is advantageous if the yarn-forming element has a plurality of twist-stop elements in the form of webs which are distributed uniformly over the inner wall in the circumferential direction of the inner wall. This creates a particularly effective rotation obstacle for the yarn produced, wherein the number of webs advantageously between 2 and 6. The radial extension of the webs can in this case vary between the individual webs or be constant throughout. The axial (with respect to the longitudinal axis of the discharge channel) expansion of the webs, for example, between 1 mm and 30 mm, preferably between 10 mm and 20 mm. Furthermore, the webs may generally have bevels at both ends or be stepped from the arranged between the web portions of the inner wall of the discharge channel.

It has particular advantages when the withdrawal channel has two sections which merge into one another into a transition region and have two inner diameter sections which deviate from one another, wherein the spin stop element is arranged in the transition region. Especially in the above range, the yarn has only a small lateral support, since the contact with the inner wall is partially lost by the widening inner diameter of the discharge channel. Now, if a torque is exerted on the yarn, it can lead to false-wire formation, which, however, can be counteracted erfindungemäß by the arrangement of one or more twist stop elements. The twist stop elements may be arranged exclusively in the transition region or extending from this in or against the spinning direction in the axial direction of the discharge channel.

Likewise, it brings advantages when the discharge channel has two in a transition region merging into each other and two divergent inner diameter having portions, wherein the spin stop element, preferably exclusively, in the region of the portion with the larger inner diameter is arranged. As already mentioned above, especially in the region with the larger inner diameter there is a risk that the yarn will take on a slightly curved course and begin to oscillate in a circular path by the action of a torque transmitted by the binder fibers (ie the yarn describes the outer contour of a balloon). Now, if the spin stop element (s) is specifically arranged in this area, an obstacle is provided at which the yarn abuts when trying to form said balloon. A rotation and thus the formation of the unwanted false wire is prevented.

It is also extremely advantageous if the spin stop element is used in the form of an insert in the yarn formation element. In this case, the spin stop element may be made of a different material than the yarn formation element. In addition, the production of an insert from a production point of view is easier than the formation of corresponding twist stop elements within the flue. The insert may have a substantially cylindrical outer contour, so that it can be inserted into a corresponding bore of the Garnbildungselements and finally form a portion of the discharge channel. Further, the insert may have on its outer side bulges or indentations, which may cooperate with corresponding counterpart portions of the bore, thereby ensuring an anti-rotation of the insert relative to the Garnbildungselement.

It is likewise advantageous if the spin stop element is detachably connected to the yarn formation element. As a result, a simple exchange of the same, for example, after a wear, possible. Likewise, the air spinning machine can be quickly adapted to the fiber material to be spun, in which the existing insert is exchanged for a matched to the new fiber material use when changing the fiber material. The twist stop element can be screwed into a corresponding bore of the yarn formation element, clipped or otherwise connected positively or non-positively with this. If no detachable connection is necessary, it is also possible to glue the components mentioned.

It is also advantageous if at least two spin stop elements are arranged in the longitudinal direction of the discharge channel, which are preferably spaced from each other by a spacer arranged therebetween. Within the distance channel a plurality of, each spaced-apart spin stop elements are present in this case, wherein the individual spin stop elements and / or spacers in turn in the form of inserts may be present. The respective swirl stop elements may be constructed, for example, in the manner of a sprocket, wherein the individual, preferably rounded teeth extend radially into the interior of the discharge channel.

Furthermore, it is advantageous if the spacer is sleeve-shaped. The spacer or spacers may, for example, have the shape of a hollow cylinder, so that they have a circular abutment surface for each adjacent swirl stop element. Although the twist stop elements have a cylindrical outer contour, they can be inserted into a central bore of the Garnbildungselements, wherein preferably a spacer is placed between each two twist stop elements.

It also brings advantages when the at least two twist stop elements delimit a passage opening for the yarn, which are arranged offset to one another with respect to the longitudinal axis in the radial direction. The twist stop elements cause in this case a (with respect to the longitudinal axis) radial deflection of the yarn within the discharge channel and can be designed as mutually rotated arranged, having an identical shape inserts. The passage openings themselves may in turn have a circular, oval, lenticular or even angular cross section.

Furthermore, it is advantageous if the spin stop element and the yarn formation element are integrally formed. In this case, can be dispensed with a subsequent connection of the respective items, wherein the twist stop elements can be created, for example, characterized in that adjacent portions of the inner wall of the flue are subsequently removed.

Particular advantages arise when the spin stop element has at least one rounded surface section. This avoids damage to the yarn, which should consciously come into contact with the twist stop element (s) in order to avoid the formation of a false twisting wire.

It also brings advantages when the yarn-forming element is designed as a spinning tip for a hollow spindle of an air-spinning machine consisting at least of spinning tip and spindle body. The spinning tip in this case has a longitudinal extent of a few centimeters and is connected to the spindle body before the start of the air spinning machine. Such a design allows a simple and quick replacement of the spinning tip, without having to replace the entire hollow spindle. Alternatively, however, the yarn-forming element can also have a longer longitudinal extent and act as a hollow spindle of the air-spinning machine without connection to other components.

The above-explained and / or reproduced in the subclaims advantageous embodiments and refinements of the invention can - in addition to z. B. in cases of clear dependencies or incompatible alternatives - individually or in any combination with each other.

Figur 1

eine teilweise geschnittene Seitenansicht einer Spinnstelle gemäß dem Stand der Technik während des Spinnprozesses,

Figur 2

einen Längsschnitt einer Spitze eines bekannten Garnbildungselements,

Figur 3

einen Längsschnitt einer Spitze eines erfindungsgemäßen Garnbildungselements,

Figur 4

einen Längsschnitt sowie einen Querschnitt entlang der Linie A-A' der Spitze eines erfindungsgemäßen Garnbildungselements,

Figur 5

einen Längsschnitt sowie einen Querschnitt entlang der Linie B-B' der Spitze eines weiteren erfindungsgemäßen Garnbildungselements,

Figur 6

einen Längsschnitt sowie einen Querschnitt entlang der Linie C-C' der Spitze eines weiteren erfindungsgemäßen Garnbildungselements,

Figur 7

einen Längsschnitt sowie einen Querschnitt entlang der Linie D-D' der Spitze eines weiteren erfindungsgemäßen Garnbildungselements,

Further advantages of the invention are described in the following exemplary embodiments. It shows:

FIG. 1

a partially sectioned side view of a spinning station according to the prior art during the spinning process,

FIG. 2

a longitudinal section of a tip of a known Garnbildungselements,

FIG. 3

a longitudinal section of a tip of a yarn formation element according to the invention,

FIG. 4

a longitudinal section and a cross section along the line AA 'of the tip of a yarn formation element according to the invention,

FIG. 5

a longitudinal section and a cross section along the line BB 'of the tip of another yarn formation element according to the invention,

FIG. 6

a longitudinal section and a cross section along the line CC 'of the tip of another yarn formation element according to the invention,

FIG. 7

a longitudinal section and a cross section along the line DD 'of the tip of another yarn formation element according to the invention,

FIG. 1 shows a partially sectioned side view of a spinning station 14 of an air-spinning machine according to the prior art. The spinning station 14 comprises a fiber guiding element 15, through which the fiber material 16 to be spun and usually present as a drawn sliver passes into the so-called swirl chamber 17 of the spinning station 14, in which finally the actual spinning process takes place. The stretching takes usually a the fiber guide element 15 upstream drafting, from which the stretched sliver is withdrawn by means of a pair of withdrawal rollers. Subsequently, the sliver is preferably detected by acting as a pair of delivery rollers 18 pair of rollers, which should be arranged as directly as possible subsequent to the fiber guide element 15 in order to avoid false warping.

After the fiber material 16 has passed the fiber guide element 15 via its guide channel 19, it passes into the effective range of several, usually tangentially into the swirl chamber 17 spinneret 20. If these are acted upon during the spinning operation via corresponding supply lines 21 with an overpressure, the result is a Vortex air flow, which flows around the upper region of Garnbildungselements 1. If the outwardly protruding fiber ends are detected by this air flow, the result is finally the desired rotation of the outer fibers (binding fibers) around the untwisted core fibers and, as a result, the desired yarn 22, which finally passes through the inlet opening 2 and the adjoining exhaust duct 4 out of the Vortex chamber 17 can be deducted.

As a result of the air flow induced by the spinnerets 20, a torque which is ultimately responsible for the yarn formation acts on the outer, so-called binding fibers. At the same time, however, this torque is also transmitted to the inner core fibers, which in principle should remain untwisted. In the worst case, this torque can lead to the core fibers also being set in rotation, so that the yarn 22 located in the draw-off channel 4 also begins to rotate. However, this rotation can not propagate indefinitely, since a withdrawal gate (eg in the form of a pair of withdrawal rollers) is arranged following the withdrawal channel 4, which conveys the yarn 22 in a clamping manner. As a result, in the area after the inlet opening 2, a so-called false-twisted wire is created, ie. H. a rotation of the yarn 22, which dissolves again in the course of its further transport. However, this ultimately leads to a loosening of the Umwindefasern and to a deterioration of the yarn strength.

As FIG. 2 can be seen, it comes through the effect of the torque described to a yarn course, which has one or more bends with respect to the longitudinal axis 3. The yarn 22 thus touches the inner wall 5 of the discharge channel 4 usually at several points and sweeps along the inner circumference, which eventually creates the unwanted false twisted wire.

In order to avoid the formation of said false-twist wire, it is now proposed according to the invention that the yarn-forming element 1 has at least one twist-stop element 6 arranged inside the withdrawal channel 4 and at least partially narrowing the cross-section of the withdrawal channel 4. The operation of the or the twist stop elements 6 and possible embodiments can be the FIGS. 3 to 7 remove.

An exemplary design of twist stop elements 6 according to the invention FIG. 3 , The twist stop elements 6 in the example shown consist of a plurality of uniformly distributed over a region of the inner wall 5 of the discharge channel 4 elevations 7, the z. B. may be formed knob-shaped. It is also conceivable to achieve the aforementioned elevations 7 by choosing a sufficiently high roughness of the inner wall 5.

Now, if a torque is transferred to the core fibers, then the form in FIG. 2 shown bends of the yarn 22, ie the yarn 22 comes in the region of the inlet opening 2 with the twist stop elements 6 in the form of the elevations 7 in contact. Since the elevations 7 counteract a movement of the yarn 22 in the circumferential direction of the inner wall 5 (finally, the elevations 7 are an obstacle that would have to be constantly swept over by the yarn 22), the formation of a false twisting wire is also hindered. The twist stop elements 6 thus generate a contact surface over which the torque transmitted to the core fibers can be absorbed. False-wire production is prevented, the yarn 22 has improved strength over the prior art.

Another way to realize the spin stop element 6 according to the invention constructively shows FIG. 4 , The twist stop element 6 comprises in shown four with respect to the longitudinal axis 3 of the discharge channel 4 radially inwardly projecting webs 8, wherein the number of webs 8 may vary. As can be seen in combination with the (not having the same scale) sectional view along the line AA ', the webs 8 are arranged uniformly distributed over the circumference of the discharge channel 4. In addition, they are integrally formed with the Garnbildungselement 1, whereby a separation into separate items would be possible. The webs 8 now form the said obstacle to the migration of the yarn bends along the inner wall 5 during operation of the air-spinning machine, so that the formation of a false-twisting wire can be reliably prevented.

Finally, the webs 8 are arranged in the transition region 9 between the two sections of the discharge channel 4 having a different inner diameter. Of course, a placement or extension in the area before or after conceivable.

A corresponding arrangement shows FIG. 5 , Here, the webs 8 extend from the transition region 9 in the axial direction of the discharge channel 4. The length of the webs 8 is variable and can be several centimeters. Also, the webs 8 may be interrupted by gaps.

Finally, the FIGS. 6 and 7 two further advantageous developments of the invention can be seen. In contrast to the variants described so far, the twist stop elements 6 shown here are distinguished by the fact that they have not been produced in one piece with the yarn formation element 1, but rather have been produced as a separate insert 10. The inserts 10 can, for example, separated by the sleeve-shaped spacers 11, pushed from below into the central bore of Garnbildungselements 1 and fixed accordingly.

While FIG. 6 Spin stop elements 6 with web-shaped extensions shows the twist stop elements 6 according to FIG. 7 crescent-shaped and limit with the central bore of Garnbildungselements 1 a lens-shaped through hole 12. By the offset of the two through holes 12 shown, the yarn 22 finally passes through a zigzag course, which reliably prevents the formation of a false twisting wire. The twist stop elements 6 in FIG. 7 also have rounded surface portions 13 to prevent damage to the yarn 22 during the deflection.

Incidentally, the invention is not limited to the illustrated embodiments. Rather, all combinations of the individual features described, as shown or described in the claims, the description and the figures and as far as a corresponding combination is technically possible or seems reasonable, the subject of the invention.

LIST OF REFERENCE NUMBERS

1

Garnbildungselement

2

inlet port

3

longitudinal axis

4

culvert

5

inner wall

6

Twist stop element

7

survey

8th

web

9

Transition area

10

commitment

11

spacer

12

Through opening

13

surface section

14

spinning unit

15

Fiber guide element

16

fiber material

17

swirl chamber

18

Pair of delivery rollers

19

guide channel

20

spinneret

21

supply line

22

yarn

Claims (15)

1. A yarn-forming element for a spinning station of an airjet spinning machine, wherein the yarn-forming element (1) comprises on one front side an inlet opening (2) as well as a draw-off channel (4) for a yarn which begins in the area of the inlet opening (2) and extends within the yarn-forming element (1) along a longitudinal axis (3), and wherein the yarn-forming element (1) comprises within the draw-off channel (4) at least one twist stop element (6) which at least partially narrows the cross-section of the draw-off channel (4), characterized in that the draw-off channel (4) comprises a contour in the area of the twist-stop element, or elements, which contour deviates from the contour of a cylindrical or truncated cone-shaped borehole.
2. A yarn-forming element according to the previous claim, characterized in that an inner wall (5) of the draw-off channel (4) in the area of the twist-stop element (6) takes a course in a cross section extending perpendicular to the longitudinal axis (3), which deviates from the course of a circle extending concentrically to the longitudinal axis (3).
3. A yarn-forming element according to any one or more of the previous claims, characterized in that the yarn-forming element (1) comprises a number of twist-stop elements (6), which are formed by raised areas (7) of the inner wall (5).
4. A yarn-forming element according to any one or more of the previous claims characterized in that the twist-stop element (6) is formed by a bar (8), which extends axially to the longitudinal axis (3) of the draw-off channel (4) and extends into the draw-off channel (4) in radial direction in relation to the longitudinal axis (3).
5. A yarn-forming element according to one or more of the previous claims, characterized in that the yarn-forming element (1) comprises a number of twist-stop elements (6) in the form of bars (8), which are arranged in circumferential direction of the inner wall (5) and preferably are uniformly distributed over the inner wall (5).
6. A yarn-forming element according to any one or more of the previous claims, characterized in that the draw-off channel (4) comprises two sections merging into one another in a transition area (9) and two sections having different inner diameters, wherein the twist-stop element (6) is arranged in the transition area (9).
7. A yarn-forming element according to any one or more of the previous claims, characterized in that the draw-off channel (4) comprises two sections merging into one another in a transition area (9) and two sections having different inner diameters, wherein the twist-stop element (6) is arranged in the area of the section having the larger inner diameter.
8. A yarn-forming element according to any one or more of the previous claims, characterized in that the twist-stop element (6) is applied in the yarn-forming element (1) in the form of an insert (10).
9. A yarn-forming element according to any one or more of the previous claims, characterized in that the twist-stop element (6) is joined to the yarn-forming element (1) in a detachable way.
10. A yarn-forming element according to any one or more of the previous claims, characterized in that at least two twist-stop elements (6) are arranged in longitudinal direction of the draw-off channel (4), said twist-stop elements (6) preferably being placed at a distance to one another by means of a distance piece (11) arranged between them.
11. A yarn-forming element according to any one or more of the previous claims, characterized in that the distance piece (11) is tube-shaped in design.
12. A yarn-forming element according to any one or more of the claims 10 and 11, characterized in that the at least two twist-stop elements (6) border a through-opening (12) for the yarn, said openings (12) being arranged offset to one another in radial direction in relation to the longitudinal axis (3).
13. A yarn-forming element according to any one or more of the previous claims, characterized in that the twist-stop element (6) and the yarn-forming element (1) are designed as one piece.
14. A yarn-forming element according to any one or more of the previous claims, characterized in that the twist-stop element (6) comprises at least one rounded surface section (13).
15. A yarn-forming element according to any one or more of the previous claims, characterized in that the yarn-forming element (1) is designed as a spinning tip for a hollow spindle of an airjet spinning machine consisting of at least a spinning tip and a spindle body.

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