CZ2005707A3 - Yarn take-off tube for spinning frames - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a yarn draw-off funnel (1) for spinning machines, in particular for non-spinning spinning machines, for conducting drained yarns during towing from a working spinning agent, as well as its manufacture. The yarn draw-off funnel (1) comprises at least two parts (2,3), the first part (2) comprising yarn guide surfaces and the second part being formed as a holder (3) for the first part, and for connecting the two parts (2,3 ), at least one of the two portions (2,3) is formed into the respective second portion (3,2) of the direct, large and heat conducting contact.

Description

(57)

The invention relates to a yarn draw-off (1) for spinning machines, in particular for open-end spinning machines, for guiding the spun yarn during the withdrawal of the yarn from the working spinning means, as well as its production. The yarn draw-off funnel (1) comprises at least two parts (2,3), the first part (2) comprising the yarn guiding surfaces and the second part being formed as a holder (3) for the first part and connecting the two parts (2,3) ), at least one of the two parts (2,3) is formed into the respective second part (3,2) in direct, large-area and thermally conductive contact.

CM

N

O • ·

P $ 34 & en:

··· ··· »’

Yarn draw-off for spinning machines

Technical field

The invention relates to a yarn draw-off for spinning machines, in particular for open-end spinning machines, for guiding the spun yarn during the withdrawal of the yarn from the operating spinning means. The invention furthermore relates to a method for producing yarn draw-offs for spinning machines, in particular for open-end spinning machines.

BACKGROUND OF THE INVENTION

The yarn draw-offs of the spinning machines, and in particular those of the yarn draw-offs used in open-end spinning machines, are components subjected to high loads in the spinning machines currently used. Thus, in open-end spinning machines, a rotor speed of 150,000 rpm and a yarn draw-off speed of 250 m / min are absolutely common, and these values may in some cases be higher than this limit. As a result of this phenomenon, the yarn draw-offs through which the spun yarn is drawn are subjected to a heavy load caused by the moving yarn. For this reason, various measures are taken in the art to extend the life of the yarn draw-off funnels. However, all known measures reach most of their limits, whereby further extension of the service life is carried out at the expense of spinning technological properties. However, these need to be maintained unchanged or even improved if possible, as the lifetime is extended. Thus, there are a number of different embodiments of ceramic exhaust funnels, which are designed as one-piece or multi-piece. In a multi-part embodiment, the ceramic part typically comprises a funnel that is glued or pressed into a steel or aluminum holder. In addition, embodiments are known in which ceramic or steel bushings are glued or pressed into the funnel holder, as shown, for example, in EP 0445554 B1.

• · · ·

PS345WCZ ř ··· «• * • ··· ·· * ·«

A disadvantage of such known solutions is, for example, that they still have a too low thermal conductivity for certain fiber materials and processing speeds. As a result, the heat produced during the spinning process is only insufficiently removed from the surface of the yarn draw-off funnel and relatively high temperatures occur. These high temperatures negatively affect the spinning process and the yarn being processed and are therefore undesirable.

Another drawback which is present in some other embodiments is that a gap is formed between the funnels and the funnel holders in which dirt may settle. This can also lead to disturbances in the spinning process. this can cause a deterioration in the quality of the produced yarn.

Known methods for producing yarn draw-in funnels, such as pressing or gluing inlet funnels of the draw-in funnels, are relatively expensive to manufacture.

It is therefore an object of the present invention to provide such a yarn draw-off funnel and a method for producing the yarn so that the funnel has sufficient thermal conductivity, is made without joints and, moreover, is cost-effective.

SUMMARY OF THE INVENTION

To solve this problem, the yarn draw-off spout is characterized in that it comprises at least two parts, the first part comprising the yarn guiding surfaces and the second part being formed as a holder for the first part, and that at least one of the two parts is shaped the other part by a direct, large-area and thermally conductive joint. It is essential that the soft or heat-softened material is shaped around the second material and thus forms a complete yarn draw-off funnel. Typically, the yarn-touching portion is a hard component to which the second portion is shaped as a soft component. This creates a direct contact that does not contain an insulating layer, such as an adhesive. In this way, the heat transfer is excellent.

44 «

4

4 4 «

4

4

444 • 4

444 »

Ρφ454ΟΖ:

4 4 4 4 44

Pouring one of the two parts onto the respective part creates a connection that is free of joints. This prevents dirt or fibers from being deposited on the yarn draw-off funnel or in the yarn. in her crack. In addition to the low susceptibility to impurities, another fundamental advantage lies in the fact that the thermal conductivity and / or the thermal conductivity are substantially improved. heat transfer from one part to the other. Compared to the state of the art, where for example either joints occur between the parts during the press-in process or glued joints are provided with the corresponding insulating effect, the invention can, due to the direct contact between the parts of the yarn withdrawal funnel, dissipate heat very well.

The second part is preferably poured onto the first part. Thus, for example, the funnel portion of the draw-off funnel comprising the yarn guiding surfaces may form a first portion and the holder may be poured thereon as a second portion. This solution is particularly advantageous if the first part is made of a particularly heat-resistant ceramic, on which the liquid material of the holder can then be poured without problems, without causing changes in the refractory first part.

The second part is preferably made of a castable material, in particular of plastic or cast metal. Numerous plastics are known here which can be processed well in the injection molding process. This is done, for example, in that the funnel part of the exhaust funnel is made of ceramic and is clamped into the mold as an insert and subsequently sprayed with plastic. Spraying can also be accomplished with a cast metal such as aluminum, zinc and copper alloys. In addition, the first portion may be made of various thermally conductive materials, such as steel. Ceramic materials with good thermal conductivity such as alumina, silica carbide or aluminum nitride are also suitable for many applications.

In general, it is particularly advantageous if the materials used exhibit a high thermal conductivity value, since this significantly reduces the temperatures occurring on the surface of the yarn draw-off funnel. The lowered temperatures have a corresponding advantageous effect on the spinning technological properties of the yarn draw-off funnel, since the handling of the processed fibers is clearly more gentle.

• • «9999«

·. PS3454GB • • • 99 • »9 • 9 • 99» 9

999

In another preferred embodiment, the first part is formed from a plurality of parts and the second part is formed at least partially to all the parts of the first part. This is particularly useful, for example, when a very long sleeve-like wear protection is provided in the yarn draw-off funnel. Then there is an option to prefabricate the funnel part of the exhaust funnel and wear protection in separate parts. According to this embodiment of the invention, both parts are fixed to each other by at least one one-piece holder. The holder is preformed on both parts of the first part, for example, embedded, sprayed or melted, after these have been previously positioned relative to each other. The holder forms the second part and closes the two parts of the first part without a joint and thus joins all the parts, respectively. parts, into a yarn draw funnel made of one piece.

In order to provide a particularly rigid connection of the parts to one another, it is advantageous for at least one part to have one or more depressions to form a positive fit, especially in the radial direction. The radial direction refers to the longitudinal axis of the yarn draw-off funnel. By forming protrusions in the radial direction, it is possible to attach the first part, respectively. a portion thereof, by positive engagement with the second portion formed as a holder. The projections can be arranged in the radial direction outwards or inwards. In either case, the projections or depressions formed are surrounded or filled by the material of the liquid-cast part during the casting process and form a shaped joint. If the protrusions or depressions are formed interrupted in the circumferential direction, i. if they are not continuous and correspond to stop surfaces in this direction, they also prevent the first part from rotating in a direction about its longitudinal axis.

In terms of thermal conductivity, it has proved particularly advantageous if at least one of the parts is thin-walled. The thin-walled design generally has the advantage that heat is transferred much better by this component. This applies, for example, to both the thin-walled design of the first part and the thin-walled design of the second part. However, the thin-walled design of the first part is also very advantageous, in which large amounts of heat are generated by the rapidly wiping yarn, which must be removed. These amounts of heat are quickly transferred through the thin-walled first portion to the second portion, and there is no overheating in this portion of the yarn draw-off funnel. In addition, it is a funnel

The BS345 ' yarn according to the invention makes it possible to form a second part, or holder, with a thinner wall than in the prior art yarn draw-offs. The yarn draw-off funnel thus formed not only saves material and does not improve thermal conductivity, but is, as a cast part, more cost-effective than known glued or pressed joints.

Another preferred embodiment of the invention, in order to improve heat dissipation, suggests that one of the parts comprises cooling fins. For example, it is advantageous for the cooling fins to be arranged at the first part and extend in the direction of the second part. When the second portion is sprayed, the cooling fins are surrounded by this spray and greatly increase the heat dissipating area. Conversely, the cooling fins may also be provided at the second portion.

For optimum operation of the yarn draw-off funnel, i.e. for a high degree of heat dissipation and good spinning technological properties of the component, it has proved to be advantageous if the contact surfaces are in the assembled state between the parts without joints. In the case of contact surfaces between the first and second parts, this can easily be done if the second part is poured or sprayed onto the first part. In this embodiment, the gapless state is produced in a particularly simple manner, which is due to the liquid material of the casting or spraying part. However, if the first part consists, for example, of two prefabricated parts, it is necessary first to ensure that the contact surfaces between the two parts are formed without joints. This can be achieved, for example, in that the parts of the first part are pressed together, preferably in the axial direction, before being sprayed with the second part.

The proposed method of the aforementioned kind is characterized in that a yarn draw-off part consisting of a plurality of parts is first formed and then a further part is connected to the first part by casting, spraying, sintering or cold-forming.

A further preferred embodiment of the method according to the invention provides that at least one of the parts is prefabricated from several parts so that the parts are placed together and subsequently joined together by at least one other part which is formed into a first part.

• · ·· · ·

: .5? S345 ^ GB

Overview of the drawings

These and other advantages and features of the invention are further elucidated on the basis of the exemplary embodiment shown in the drawing, in which FIG. 1 is an oblique view of a yarn draw-off according to the invention, FIG. Fig. 2 is an axial sectional view of the yarn draw-off spout of the invention of Fig. 1; 3 shows an axial section through a second embodiment of the yarn draw-off according to the invention, and FIG. 4 is a radial cross-sectional view of the yarn draw-off according to the invention of FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows the yarn draw-off funnel 1 in an oblique front and top view. On the front side of the yarn draw-off funnel 1 facing the spinning device (not shown) there is a funnel part 2 of the draw-off funnel which is surrounded by the holder 3. At the rear end of the yarn draw-off funnel 1 the rear end of the wear protection 4 can be detected. Between the funnel part 2 of the extraction funnel and the holder 4, a first boundary 5 of the parts is shown. At this limit of 5 parts, the funnel part 2 of the take-off funnel, which forms the first part, meets the holder 3 which forms the second part. The second boundary 6 of the parts is located at the transition point between the holder 3 and the wear protection 4. The funnel part 2 of the draw-off funnel is additionally equipped with notches 7, which are designed to influence the movement of the moving yarn in a controlled manner.

FIG. 2 shows the yarn draw-off funnel already described in FIG. 1 in axial section. On the left-hand side there is a funnel part 2 of the exhaust funnel, which in this embodiment is made of ceramic. This ceramic is advantageously particularly thermally conductive, i.e. it has a high thermal conductivity coefficient. In addition, the funnel part 2 of the exhaust funnel should be designed with a wall as thin as possible in order to guarantee an optimal heat transfer. In the cross-sectional view, notches 7 can be clearly identified to ensure the spinning technological properties of the yarn draw-off funnel. The funnel part 2 of the extraction funnel is surrounded by a holder 3, which is formed as a cast part. In this embodiment, cast metal was chosen as the material for the holder. An alternative for cast metal is possible on this

:.: ps345 & cz plastic application site. Here again, plastics with good thermal conductivity are preferred. In this embodiment, the thermal conductivity of the yarn draw-off funnel is particularly positively influenced by the fact that the contact surfaces 8 between the holder 3 and the funnel part 2 of the draw-off funnel have direct, large-area and immediate contact between the two portions. No interfering air gaps or insulating layers, such as adhesive layers, interfere with the heat transfer. In order to further improve the heat transfer process, the cooling fins 9 shown in dashed lines can also be provided at the funnel funnel 2, which, once the funnel funnel part 2 has been sprayed, extend into the holder 3 and additionally transfer heat over the enlarged surface.

The illustrated embodiment represents a yarn draw-off spigot made up of a plurality of parts, the first part being formed by a funnel part 2 of the draw-off funnel and a connected wear protection 4. The second part of the yarn draw-off funnel 1 in this embodiment consists of a holder 3. In the manufacture of the multi-part yarn draw-off funnel 1, the funnel part 2 of the draw-off funnel and the wear protection 4 are first produced. spraying, respectively. by pouring the liquid material of the holder 3 into one unit. In order to achieve the correct alignment of the funnel part 2 of the funnel and of the wear protection 4, these have a straight face 10 which ensures correct positioning in the axial direction. In order to additionally guarantee the positioning in the radial direction, the two parts can be removed during the casting process. injection molding, clamp for example on a mandrel. During the spraying or casting process, an appropriate axial pressure should be exerted on the funnel part 2 of the extraction funnel or on the holder 3 in order to compress the two parts together and to ensure a jointless design. In order to prevent the wear protection 4 from unintentionally detaching from the connection later, it is provided in the radial direction with depressions 11 into which the material of the holder 3 is sprayed on or in the case of injection molding. molding. This results in a positive fit between the holder 3 and the wear protection 4. Besides the illustrated multi-part embodiment of the first part, it is entirely possible to arrange the funnel part 2 of the exhaust funnel and the wear protection 4 as a one-piece component. According to the invention, the holder 3 can be used. • In such an embodiment, pour or re-pour it in such an embodiment. inject.

Moreover, in the embodiment of FIG. 2, the diameter of the wear protection 4 at the narrowest point is slightly larger than the smallest diameter of the funnel portion of the take-off funnel to ensure that the drawn yarn does not strike the projection inside the yarn funnel. In addition, a circumferential bevel 12 is advantageously arranged in the region of the front side, which also prevents any wear protrusions 4 from interfering with the yarn channel.

The embodiment according to FIG. 3 shows an axial section through a second embodiment of the take-up funnel and the yarn according to the invention. The cutting arrangement corresponds to line A-A in FIG. 4. This yarn draw-off funnel 1 consists of three parts, the funnel part 2 of the draw-off funnel and the wear protection 4 forming the first part and the holder 3 the second part. In this embodiment, the wear protection 4 is designed as a short sleeve, on the inside of which four ribs 13 are disposed 90 ° apart. Ribs 13 are needed to achieve certain yarn qualities. In other applications, it is sensible to use a yarn draw-off funnel without ribs 13. Such a yarn draw-off funnel is then appropriately provided with a smooth wear protection 4. In order to secure a secure grip of the wear protection 4 in the illustrated holder 3, a groove 11 in the form of a groove 11 is located at the top and bottom of the wear protection 4, which is completely filled with the embedded holder 3. Together with the chamfer 14 located on the right side of the protection 4 the wear protection 4 in the holder 3 is secured against unwanted movements both in the axial direction and in the circumferential direction.

The holder 3 shown here extends over approximately the entire length of the yarn draw-off funnel 1 and surrounds the two parts of the first part, without gap. With the foregoing exemplary embodiment, it will be appreciated that the geometry of the parts and the number of parts of the parts can be easily adapted to the requirements without limiting the advantages of the invention or completely abolishing them.

Giant. 4 finally shows a radial section of the yarn draw-off according to the invention according to FIG. 3. In this view, the formation of a groove 11 in the form of a groove in the wear protection 4 and the associated anti-wear safety device can be recognized.

:.: PS34 ^ en 9 9 9 9 9

999 9 9 99 999 99 999 rotation in the circumferential direction. It is also well recognizable that the wear protection 4 is seated in the gap-free holder 3, thereby creating a particularly large effective heat transfer surface at the second boundary 6 of the parts. The yarn draw-off funnel 1 thus formed exhibits excellent heat dissipation properties and thus particularly good spinning technological properties as well as a particularly long service life.

Further, the invention is not limited to the illustrated embodiments.

A large number of modifications to the invention are possible within the scope of the claims.

Thus, a plurality of castable metal alloys or castings can be used to produce the holder. metal alloys suitable for their injection molding capability. In addition, a large number of suitable plastics can be selected for manufacturing the holder 3. In addition, the number and type of fitting between the holder and the funnel part 2 of the suction funnel or the funnel can be varied. wear protection 4.

The parts of the yarn draw-off funnel 1, such as the wear protection 4, can also be formed as a funnel sleeve, and these can be made of hardened steel, which easily tolerates the temperatures occurring in a later casting or injection molding process to form the second portion.

:.: PS3434EN:.: · ♦ ·· „• · · · · · · · · · · · · · · ·

List of reference numbers funnel yarn funnel part funnel retainer wear protection first part limit second part limit notch contact surface cooling fin front side bevel recess

Claims (16)

PATENT CLAIMS A yarn draw-off for spinning machines, in particular for open-end spinning machines, for guiding the spun yarn during the yarn withdrawal from the working spinning means, characterized in that 5 the yarn funnel (1) comprises at least two parts ( 2,3), wherein the first part (2) comprises the yarn guiding surfaces and the second part is formed as a holder (3) for the first part, and that at least one of the two parts (2, 2, 3) 3) formed into a respective second part (3,2) in direct, large-area and thermally conductive contact. The yarn draw-off spout according to the preceding claim, characterized in that one of the two parts (2,3) is poured onto the second part (3,2), in particular the second part (3) on the first part (2). Yarn draw-off spout according to one of the preceding claims, characterized in that the second part (3) is made of a castable material, 15 in particular of plastic or cast metal. Yarn draw-off according to one of the preceding claims, characterized in that the materials used have high thermal conductivity values. A yarn draw-off spout according to any one of the preceding claims, characterized in that the first part (2,4) is formed of several parts and the second part (3) is at least partially formed into all parts of the first part (2,4). Yarn draw-off spout according to one of the preceding claims, characterized in that at least one part (2,3,4) is provided with one or more depressions (11) to form a positive joint, in particular in the radial direction. 25 Yarn draw-off spout according to one of the preceding claims, characterized in that at least one of the parts (2,3,4) is designed with a thin wall. Yarn draw-off spout according to one of the preceding claims, characterized in that one of the parts (2,3,4) comprises cooling fins (9). : .3? S345 »EN • · φ · · · The yarn draw-off spout according to one of the preceding claims, characterized in that in the assembled state the contact surfaces (8) between the parts (2,3,4) are free of joints. Method for producing a yarn draw-off funnel for spinning machines, in particular for open-end spinning machines, characterized in that first a part (2,4) of the yarn draw-off funnel (1) is formed which consists of several parts and then another a portion (3) formed into a first portion (2,4). Method according to the preceding claim, characterized in that the further part (3) is connected to the first produced part (2,4) by a casting process. 10 Method according to one of the preceding claims, characterized in that at least one of the parts (2,3,4) is prefabricated from a plurality of parts (2,4), that the parts (2,4) are then positioned relative to one another and subsequently on these are connected to each other by at least one other part (3). Method according to one of the preceding claims, characterized by 15, in that the parts (2,3,4) are co-embedded, in particular the part (3) being poured onto the second part (2,4). Method according to one of the preceding claims, characterized in that the parts (2,3,4) are sprayed together, in particular the part (3) being sprayed onto the second part (2,4). 20 May Method according to one of the preceding claims, characterized in that the parts (2,3,4) are joined together by a sintering process. Method according to one of the preceding claims, characterized in that the parts (2,3,4) are joined together by a cold forming process of at least one of the parts (2,3,4).