EP2400049B1 - Thread draw-off nozzle - Google Patents

Description

The present invention relates to a yarn take-off nozzle for an open-end spinning apparatus having a take-off nozzle hopper for diverting a produced yarn during yarn take-off, which includes a yarn deflection zone.

Thread withdrawal nozzles for open-end spinning machines are known in the prior art in many versions. The yarn withdrawal nozzles are in this case mounted in a yarn withdrawal channel of the open-end spinning device and serve to guide and deflect the yarn produced in the spinning rotor during yarn withdrawal. Due to the constant contact of the drawn through the thread take-off yarn it comes into operation, especially at high rotor speeds and thus high take-off speeds, to a considerable heat development at the thread take-off. If this heat is not sufficiently dissipated, the high temperatures can lead to damage to the yarn and yarn breaks. Likewise, this can lead to contamination of the trigger nozzles. On the other hand, it is necessary by the continuous threadline on the trigger nozzle to perform the exhaust nozzles of a wear-resistant material.

Thread withdrawal nozzles are known in which the withdrawal nozzle funnel is made in one piece from a metallic material. Although a very good heat dissipation from the surface of the trigger nozzle funnel is achieved, it is necessary to provide these materials with a wear protection coating. However, such coatings can be applied only on a smooth surface and in easily accessible areas in a uniform and sufficient layer thickness. By contrast, in the area of macrostructures, such as notches or spirals, as well as the nozzle bore, the coatings are formed only insufficiently, so that considerable wear can occur there. It can also Irregularities in the coated surface can damage the yarn.

To also improve the wear resistance of the nozzles in these areas, suggests the EP 0 445 554 B1 to carry out a main body of the yarn draw-off of a thermally conductive, metallic material and to use in this body a nozzle funnel made of a wear-resistant ceramic material. Due to the comparatively poor thermal conductivity of the ceramic material, however, inadequate heat dissipation from the surface of the nozzle funnel and overheating may occur.

The JP S54 4407 B also shows a two-part vent nozzle. The withdrawal nozzle funnel is formed in two parts, wherein a first part of the Garnumlenkzone is disposed on an outer part, while a second part of the Garnumlenkzone is disposed on an inner, usable in the outer part part.

The DE 10 2005 045 817 A1 also shows a yarn withdrawal nozzle with a wear-resistant ceramic nozzle funnel. In order to improve the heat dissipation of the ceramic nozzle funnel to the nozzle body, the document proposes to mold the nozzle funnel with the nozzle body in a direct heat-conducting contact, for example, pour. Nevertheless, even here at the surface of the nozzle funnel, which is in contact with the withdrawn yarn, very high surface temperatures still occur, so that frequently the rotor speeds are limited by the thermal load on the draw-off nozzle.

The object of the present invention is therefore to propose a yarn draw-off nozzle which further improves the heat dissipation from the yarn-contacting surface of the nozzle funnel.

The problem is solved by the features of claim 1. A yarn withdrawal nozzle for an open-end spinning device has a draw-off funnel for deflecting a produced yarn during the yarn take-off, which contains a yarn deflection zone. According to the invention, the draw-off funnel is formed in two parts, with an outer part, which contains a first area of the yarn deflection zone, and with an inner part, which contains a second area of the yarn deflection zone. The two parts are made of different materials and / or are provided with different coatings at least in the areas of the yarn deflection zone. According to another advantageous embodiment, however, only one of the two parts is provided with a coating, while the other part is uncoated. While in the prior art, a complete deduction nozzle funnel made of ceramic was used in the discharge nozzle, it is now possible by the invention division of the trigger nozzle, according to the loads of the individual areas of Garnumlenkzone and according to the requirements of the individual areas on the thermal conductivity to equip the trigger nozzle funnel in an optimal manner and protect. By appropriate choice of material this can at the same time the heat dissipation from the Garnumlenkzone be improved, or a coating can be applied only where it is absolutely necessary for wear protection.

Advantageously, a transition point between the outer part and the inner part outside the Garnumlenkzone against the Faserleitfläche is set back so that any existing burrs, protrusions or notches do not come into contact with the yarn and this can not damage.

The invention has recognized that, in particular in the outer region of the nozzle funnel, the high circumferential speed of the drawn-off yarn results in a high frictional energy and thus in very high surface temperatures and local overheating. The invention sees Therefore, before the outer part of the discharge nozzle funnel preferably made of a material, preferably a metal, with a high thermal conductivity, since in this area the requirements for the thermal conductivity are increased. However, suitable wear protection coatings can still provide adequate protection of the outer part of the trigger nozzle funnel.

The inner part, which is subjected to lower thermal loads due to the smaller yarn peripheral speed, is made according to an advantageous embodiment of the invention of a material with a high wear resistance and / or provided with a coating with a high wear resistance. Preferably, the inner part is wear-resistant made of a ceramic material. Since only the inner part of the exhaust nozzle funnel is made of the ceramic material, good heat dissipation to the exhaust nozzle or the environment can be achieved despite the comparatively poor thermal conductivity of the ceramic material. At the same time, the design of the inner part of the nozzle funnel made of a ceramic material offers the possibility of attaching structures such as notches or spirals. By means of the embodiment according to the invention of a two-part draw-off nozzle funnel, it is thus possible to optimally combine the requirements for wear protection and heat dissipation and to considerably improve the heat dissipation from the outer part of the draw-off nozzle funnel.

Advantageously, the yarn draw-off nozzle furthermore comprises a nozzle holder and / or a discharge nozzle shaft for fastening the draw-off nozzle in the spinning device. If the draw-off nozzle is provided as a shaftless nozzle, the nozzle holder is fastened to the spinning device by means of one or more fastening means, for example magnets.

It is particularly advantageous if the outer part of the draw-off nozzle funnel and the nozzle holder and / or the draw-off nozzle shank are integral with one another are formed and form a nozzle body. The heat dissipation from the haul-off funnel is thereby further improved, since no gaps or insulating layers are to be overcome between the outer part of the haul-off nozzle and the discharge nozzle shaft. In addition, the production is simplified thereby.

A further advantageous embodiment of the invention provides that the inner part is designed as a ceramic insert, which is insertable into the outer part and / or in the nozzle holder and / or in the discharge nozzle shaft. The assembly of the individual parts of the exhaust nozzle and the attachment of the inner part is thus possible in a favorable manner.

In order to achieve the best possible heat dissipation from the yarn deflection zone as well as heat dissipation into the surroundings of the yarn withdrawal nozzle, the outer part of the discharge nozzle funnel and / or the discharge nozzle shaft consists of a material with a thermal conductivity of at least 100 W / mK. In particular, in this case aluminum or copper or their alloys are suitable because they are processed in a favorable manner.

In order to achieve sufficient wear protection in the outer part of the draw-off nozzle funnel in addition to the good heat dissipation, this is coated at least in a Garnumlenkzone with a wear protection layer. It is particularly advantageous if the wear protection layer has a high thermal conductivity. As a result, heat dissipation from the surface of the trigger nozzle funnel can be ensured despite the improved wear protection. In order to further improve the heat dissipation, the wear protection layer is preferably made as thin as possible.

If the take-off nozzle funnel and the take-off nozzle shaft are integrally formed with each other, then it is advantageous if the nozzle body is coated with a wear-resistant layer having a high thermal conductivity. As a result, not only the particularly loaded Garnumlenkzone the outer part of the Abzugsdüsig-richters, but also all surfaces of the Abzugsdüse, which can come into contact with the yarn can be protected from wear.

According to a particularly advantageous embodiment of the invention, the wear protection layer is a hard material or diamond coating. The hard material or diamond coating can be applied here in a PVD or a CVD process or else galvanically. As a diamond coating is, for example, a galvanically applied nickel-phosphorus diamond coating in question. Likewise, DLC coatings (DLC - diamond-like-carbon) are possible, which can be applied in a PVD or a CVD process. This has a high thermal conductivity and can be applied very thinly in a favorable manner. Nevertheless, it has the required hardness and wear resistance.

According to another advantageous development of the invention, the ceramic insert has radially arranged notches or spirals in order to influence the guidance of the thread and the unwinding of the thread. Due to the two-part design of the trigger nozzle funnel, it is optimally possible with improved heat dissipation to attach the desired macrostructures on the surface of the nozzle funnel and design wear-resistant. In the case of a one-piece, metallic nozzle funnel, on the other hand, in the area of such macrostructures, it is scarcely possible to achieve sufficient protection against wear since coatings can not be uniformly applied to a surface having such structures. On the other hand, a one-piece ceramic nozzle funnel has the required wear resistance in the area of such surface structures, but only offers insufficient heat dissipation. It is advantageous in the two-part design of a trigger nozzle funnel that the formation of the macrostructures and the radius and length of the trigger nozzle funnel can be varied. With the two-part embodiment of the invention Nozzle funnel with a ceramic insert which forms the inner part of the nozzle funnel, it is possible to achieve a good heat dissipation with maximum wear resistance and free surface design.

It is furthermore particularly advantageous if a wear protection bush made of steel or ceramic is subsequently arranged in the yarn draw-off nozzle on the draw-off nozzle funnel. In this inner region of the draw-off nozzle, the heat generation is comparatively low, so that it can also be produced from a comparatively poorly heat-conductive ceramic material. However, the wear protection bushing can also be performed in a favorable manner as a hardened steel part or with a wear-resistant coating steel part.

According to a particularly advantageous embodiment of the invention, the ceramic insert is formed integrally with the wear protection bushing. The preparation of the draw-off nozzle is thereby simplified, since only one part is to be handled. In particular, in the case of a one-piece design of the discharge nozzle funnel and the discharge nozzle shaft with such a one-piece ceramic insert, the production of the extraction nozzle and the heat dissipation is improved, since there is an improved heat-conducting contact.

Furthermore, it is advantageous if the ceramic insert is glued or pressed. Since a particularly good heat dissipation from the thermally loaded Garnumlenkzone in the outer part of the nozzle funnel is due to the two-part design, no adverse insulating effects are achieved by sticking the ceramic insert. The preparation of the yarn draw-off nozzle is thereby simplified.

Fig. 1

eine erste Ausführung einer Fadenabzugsdüse, welche in einer Offenendspinnvorrichtung montiert ist sowie

Fig. 2

eine weitere Ausführung einer erfindungsgemäßen Fadenabzugsdüse

Fig. 3

eine weitere Ausführung einer erfindungsgemäßen Fadenabzugsdüse als schaftlose Düse sowie

Fig. 4

eine weitere Ausführung einer erfindungsgemäßen Fadenabzugsdüse mit einer separaten Düsenfassung.

Further advantages of the invention will be described with reference to the embodiments illustrated below. Show it:

Fig. 1

a first embodiment of a yarn withdrawal nozzle, which is mounted in an open-end spinning device and

Fig. 2

a further embodiment of a yarn withdrawal nozzle according to the invention

Fig. 3

a further embodiment of a yarn withdrawal nozzle according to the invention as a shaftless nozzle and

Fig. 4

a further embodiment of a thread take-off nozzle according to the invention with a separate nozzle holder.

Fig. 1 shows a vent nozzle 1 according to the invention, which is fixed in a known manner in a cover 2 of a rotor housing, not shown here. The draw-off nozzle 1 serves to deflect and guide the yarn 5 produced in the spinning rotor 4, which in the present case is indicated merely by a dot-dash line. The spinning rotor 4 in this case runs at speeds of up to 150,000 revolutions per minute, wherein the produced yarn 5 is withdrawn at take-off speeds of for example 250 m / min. Due to the rotation of the rotor 4, the yarn 5 runs on the surface of the take-off nozzle 1 in a crank-like manner.

In the present case, the draw-off nozzle 1 consists of a draw-off funnel 6, on which the yarn 5 is deflected, and of a draw-off nozzle shaft 7, by means of which the draw-off nozzle 1 is fastened in the cover 2 of the spinning device. Due to the constant contact with the crank-like circumferential and withdrawn at high speed yarn 5 it comes to the surface 8 of the trigger nozzle 6 to a considerable heat generation by frictional heat. In addition, in particular the area of the trigger nozzle funnel 6 is subject to heavy wear due to the constant yarn movement.

Conventionally, therefore, in the prior art, the exhaust nozzle funnels 6 were made of a ceramic material having a very high wear resistance. The disadvantage here, however, that such ceramic materials have a comparatively poor thermal conductivity of less than 30 W / mK, so that it came with the enormous heat development by the withdrawn and rotating thread to an insufficient heat dissipation. In particular, in the processing of thermally sensitive chemical fibers, the open-end spinning machines must therefore be operated at reduced speed in the prior art in order to avoid such overheating, although purely technically higher rotor speeds and take-off speeds would be possible.

The invention has now recognized that, in particular in the outer region of the nozzle funnel 6 with a larger diameter, a very high temperature development occurs due to the higher peripheral speed of the yarn, which can only be insufficiently removed on account of the ceramic materials used. Due to the particularly smooth surface in the area of the yarn deflection zone 3 (see Fig. 2 and 4 ) and the continuous contact of the yarn 5 in this area, the temperature development is further enhanced. The invention therefore proposes to design the trigger nozzle hopper 6 in two parts, each of the parts containing a region 3a, 3b of the yarn deflection zone 3. The outer part 6a of the discharge nozzle funnel 6 is made of a preferably metallic material with the highest possible thermal conductivity. In this way, optimal heat dissipation from the surface 8 of the discharge nozzle funnel 6 to the environment, here the take-off nozzle shaft 7 and the cover 2, take place. The inner part 6b, however, consists of a material with a high wear resistance, in particular a ceramic material, and is embodied here as a ceramic insert 9. This makes it possible to carry out the discharge nozzle 1 particularly wear-resistant and yet to influence the movement of the sweeping yarn 5 by various structures, such as notches 10 or spirals. By means of the inventive design of a yarn withdrawal nozzle 1 with a two-part deduction nozzle hopper 6, it is thus possible to optimally combine the requirements of wear resistance and an optimized Garnbeeinflussung with optimized heat dissipation and thereby improve the spinning results. In particular, in the processing of man-made fibers or synthetic fibers, contamination of the thread-guiding surfaces on the draw-off nozzle funnel 6, which can lead to thread breaks and damage to the yarn 5, can be avoided. Due to the greatly improved heat dissipation in the outer part 6a of the trigger nozzle overheating be avoided, so that the rotor speed is no longer limited by the temperatures at the discharge nozzle 1.

Like from the FIGS. 1 and 3 it can be seen here is the transition point 14 between the outer part 6a and the inner part 6b slightly recessed from the surface 8 of the trigger nozzle funnel 6 and thus arranged outside the Garnumlenkzone 3. Damage to the overlying yarn 5 by protruding burrs or other irregularities of the surface 8 in this area can thus be prevented.

To FIG. 1 For example, the outer part 6a of the exhaust nozzle funnel 6 and the exhaust nozzle shaft 7 are integrally formed with each other from a thermally conductive material. The heat conduction is thereby improved, since no more gaps or insulating adhesive layers have to be overcome. The production of such a one-piece nozzle body can also be carried out economically. In order to achieve a good wear protection on the outer part 6a of the trigger nozzle funnel 6, this is at least in the area of the yarn deflection zone, which in Fig. 2 is indicated by a dotted line, provided with a wear protection layer. For this are hard or diamond coatings in question, which have good thermal conductivity and are relatively thin applicable. The heat conduction is thus not affected by the application of a wear protection layer.

As shown, the ceramic insert 9 is extended so that it contains a part of the nozzle bore 11. The ceramic insert 9 at the same time includes a wear protection bushing 12, which adjoins the vent nozzle funnel 6 in the interior of the draw-off nozzle 1. The manufacture and assembly of such a thread take-off nozzle 1 is thereby particularly simple and economical. Due to the very good heat dissipation from the most heavily used thread contact zone, the ceramic insert 9 can be glued or pressed in a simple manner in the Abzugsdüsengrundkörper.

The thread take-off nozzle 1 of Fig. 2 and 4 In contrast, has a separate wear protection sleeve 12. This can be designed as a ceramic insert or as a steel insert and also be glued or pressed into the nozzle body. Also in this embodiment, the benefits of improved heat dissipation from the most stressed yarn diverting zone to various structures 10 for influencing yarn twist and yarn movement as well as good wear protection can be optimally combined.

In contrast to the exhaust nozzle 1 of FIG. 2 includes the exhaust nozzle 1 of FIG. 4 in addition to the haul-off funnel 6 with its two parts 6a, 6b, a separate nozzle holder 13, which is present in one piece with the shaft 7 is connected.

FIG. 3 shows a discharge nozzle 1 according to the invention in an embodiment as a shaftless nozzle. The withdrawal nozzle 1 is in this case merely by means of a socket 13, which, as shown in the present case, can also be made in one piece with the outer part 6a of the discharge nozzle funnel attached to the cover 2 of the rotor housing. A wear protection bushing 12 can also be used directly in the cover 2 here.

The invention is not limited to the illustrated embodiments. Variations and combinations within the scope of the claims also fall under the invention.

LIST OF REFERENCE NUMBERS

1

off nozzle

2

cover

3

Garnumlenkzone

4

spinning rotor

5

yarn

6

Navels funnel

7

Navels shaft

8th

Surface of the trigger nozzle funnel

9

ceramic insert

10

notch

11

nozzle bore

12

Wear protective sleeve

13

nozzle fitting

14

Checkpoint

Claims (15)

1. Thread draw-off nozzle (1) for an open-end spinning device with a draw-off nozzle funnel (6) for deflecting a produced yarn (5) during the yarn draw-off process that contains a yarn deflection zone (3), the draw-off nozzle funnel (6) having a two-part design with an external part (6a) containing a first area (3a) of the yarn deflection zone (3) and an internal part (6b) containing a second area (3b) of the yarn deflection zone (3), characterized in that both parts (6a, 6b) are made of different materials and/or have different coatings at least in the areas (3a, 3b) of the yarn deflection zone (3) and/or only one of the two parts (6a, 6b) has a coating.
2. Thread draw-off nozzle according to the previous claim, characterized in that the external part (6a) is made of a material, preferably of a metal with a high thermal conductivity.
3. Thread draw-off nozzle according to one of the previous claims, characterized in that the internal part (6b) is made of a material highly resistant to wear, preferably of ceramic material, and/or has a coating highly resistant to wear.
4. Thread draw-off nozzle according to one of the previous claims, characterized in that the thread draw-off nozzle (1) further encompasses a nozzle holder (13) and/or a draw-off nozzle shaft (7) for securing the draw-off nozzle (1) in the spinning device.
5. Thread draw-off nozzle according to one of the previous claims, characterized in that the external part (6a) of the draw-off nozzle funnel (6) and the nozzle holder (13) and/or the draw-off nozzle shaft (7) have a one-part design together and form a nozzle main body.
6. Thread draw-off nozzle according to one of the previous claims, characterized in that the internal part (6b) is made as a ceramic insert (9) that can be inserted in the external part (6a) and/or in the nozzle holder (13) and/or in the draw-off nozzle shaft (7).
7. Thread draw-off nozzle according to one of the previous claims, characterized in that the external part (6a) and/or the draw-off nozzle shaft (7) is/are made of a material with a minimum thermal conductivity of 100 W/mK, especially of aluminum or copper.
8. Thread draw-off nozzle according to one of the previous claims, characterized in that the external part (6a) is coated, at least in the yarn deflection zone (3), with a wear-resistant layer, preferably with a wear-resistant layer having a high thermal conductivity.
9. Thread draw-off nozzle according to one of the previous claims, characterized in that the nozzle main body is coated, at least in the area of a nozzle bore hole (11), with a wear-protective layer, preferably with a wear-protective layer having a high thermal conductivity.
10. Thread draw-off nozzle according to one of the previous claims, characterized in that the wear-protective layer is a hard material or diamond coating.
11. Thread draw-off nozzle according to Claim 6, characterized in that the surface of the ceramic insert (9) has macro structures, especially radially arranged notches (10).
12. Thread draw-off nozzle according to one of the previous claims, characterized in that a wear protection bushing (12) made of steel or ceramic is arranged in the thread draw-off nozzle (1) subsequently to the draw-off nozzle funnel (6).
13. Thread draw-off nozzle according to Claim 6 or 11, characterized in that the ceramic insert (9) is executed as one-part with the wear protection bushing (12).
14. Thread draw-off nozzle according to the claims 6, 11, or 13, characterized in that the ceramic insert (9) is glued or pressed in.
15. Thread draw-off nozzle according to one of the previous claims, characterized in that there is a transition point (14) lying outside of the yarn deflection zone (3), between the external part (6a) and the internal part (6b).

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