EP1321547A1 - Cross-wound bobbin of cylindrical shape, and corresponding winding method - Google Patents

Abstract

To wind cylindrical cross wound bobbins (3), at a rotor spinning machine, the wound body (12) is formed by a reciprocating yarn guide to give a yarn intersection angle ( alpha M) at the center zone (22) which is ≤ 26 degrees . The yarn angle towards the end zones (20,21) has a larger yarn intersection angle ( alpha R). The center zone of the bobbin is ≥ 50% of the total bobbin width (BWG).

Description

The invention relates to a cylindrical cheese and a Method of forming the winding body of a cylindrical Cross-wound bobbin with a thread guide according to the preamble of Claims 1 and 7.

Yarn made on rotor spinning machines differs compared to the ring spun yarn in the bobbin and in Flow behavior. The rotor yarn is less hairy than that Ring spun yarn and can thus be more easily unwound (easier lifting), but has a greater tendency to curl than the ring spun yarn, so that the wound yarn in Edge area of the package from the overlying ones Yarn layers is pushed outwards. This can result in a over the normal spool stroke of 150 mm, for example beyond, up to a width of 170 to 180 mm form fully-grown cheese. In such a case comes a desired coil structure with flat end faces is not more come about. Such phenomena occur with yarns natural fibers such as cotton, especially for coarse ones Yarn on and are more pronounced, the coarser the yarn is.

Problems on the end faces of bobbins can also already in the preliminary stage of yarn production with wound up Fibrous webs or rovings occur. US 954,344 describes that in the case of rovings or rovings that do not or are only slightly rotated in the winding structure on the end faces Bulges occur. This adverse effect occurs here on, although the laying angle in the prior art usual is more than 32 °. This is favored by the soft and loose structure of the fiber strands. such Bulges can further processing the winding body significantly affect. According to US 954,344, the Bulges can be prevented by the rest of the constant installation angle in the edge area of the winding body is increased.

Used in the package winder at high thread speeds worked, it may be due to medium and coarse yarns the inertia of the thread lead to the thread at the deflection points of the lifting movement over the edge of the spool moved out and a so-called skip error occurs. This error leads to thread breaks and hinders them Further processing of the yarn.

The likelihood of such errors occurring significantly influenced by the crossing angle α. At the Manufacturing cross-wound bobbins is therefore the choice of each Crosshair angle of great importance. While at the Production of a cheese with a "wild winding" Cross-hair angle constant over the entire bobbin travel remains, the crosshair angle changes at a Cheese with "precision winding" by increasing with Cross-bobbin diameter decreases. The advantages of Precision winding is, among other things, that a Cross-wound bobbin with precision winding longer run length for the same Spool volume compared to a cheese in a wild winding having. The decreasing as the cross-bobbin diameter increases However, the crossing angle limits the maximum allowed Diameter in the manufacture of precision coils Staple fiber yarns, especially for staple fiber yarns Avoidance of the defects occurring at the edges arbitrarily small crossing angles can be wound. Out for this reason, such as in the generic DE 100 15 933 A1 described, at Rotor spiders avoid crossing angles of less than 28 ° become. This makes the precision winding, especially when Winding staple fiber yarns, of limited use.

In a third type of winding, the "step precision winding", becomes an approximation of the coil journey constant crossing angle aimed. Even with the Step precision winding are the ones described above Density problems or problems with the stability of the In practice, the coil edge is only slightly reduced, however not resolved.

In the case of conical cross-wound bobbins, which have a circumferential friction of Roller driven, it is necessary to drive only within the predetermined range of a narrow rub zone or the friction zone of the cheese to let. Because with conical coils, the coil circumference length over seen the coil axis is different, the speed the bobbin swaying and uncontrollable when the too winding conical cheese with increasing reel diameter Contact with the left and right of the predetermined one Parts of the roller-shaped friction zone Drive device takes. To avoid this, in an area limited to the friction zone of the Crosshair angle one in DE-AS 26 32 014 or in parallel U.S. Patent No. 4,266,734 shown conical cheese opposite the Crosshair angle outside the friction zone reduced. As a result, the compressive strength of the winding body in the predetermined friction zone slightly increased. The reason for Formation of a drive zone with a higher specific pressure by changing the spool on the drive roller the crosshair angle is, however, only by the different coil circumference lengths with conical Given bobbins.

New machine technologies, especially in weaving, such as Air jet weaving machines, for example, place increased demands with regard to the running properties of the yarn. The Requirements can be met with the known coil designs not or only insufficiently.

The invention is based on the object known cylindrical cross-wound bobbins improved cylindrical Cross-wound bobbin and a method for its manufacture Rotor spinning machines, especially when producing coarse ones Yarn to create.

The object is achieved by a method according to claim 1 and cylindrical cheese according to claim 7 fulfilled.

The subclaims relate to advantageous embodiments of the Invention directed.

The invention is based on the knowledge that in opposite the crossing angle in the central part larger crossing angles in Edge area of the package the crossing angle in remaining wider middle section clearly compared to usual Crossing angles can be reduced without the one Reduction of the crossing angle over the entire Wrapping width known disadvantages in purchase to have to take. Lowering the crossing angle can thereby being pushed far without becoming one impermissible hardening of the cheese.

The invention leads to an improved flow of the thread from the cylindrical cheese. The thread flow is calmer, counteracts loop formation and yarn entanglement and thus allows higher thread take-off speeds. The Coil structure, especially on the end faces of the cylindrical cheese, is improved. The barrel length of the Yarns with the same bobbin diameter show up opposite a common cylindrical cheese of the same winding type clearly increased.

The formation of the crossing angle α according to one of claims 2, 3 and 4 and 8, 9 and 10 leads to an increase in the wound thread length, with excellent stability of the cylindrical bobbin can be maintained at high density. The crossing angle α advantageously increases continuously from the crossing angle α _{M of} the central zone to the crossing angle α _{R of} the peripheral zone. The edge zones can be dimensioned such that they do not occupy more than 15% of the total winding width B _WG .

One with increasing coil diameter Reduction of the bobbin support pressure according to claim 5 and a reduction in the thread tension according to claim 6 ensures that Suppress an undesirably high yarn pressure crossing angles α according to the invention which are smaller than 28 ° are. The spool contact pressure is known to consist of the Weight of the coil and the weight of the coil frame together as well as from the force that comes from, for example, one Torque sensor applied torque results. The Spool contact pressure can be reduced so that not only the coil weight is compensated, but one above additional discharge occurs.

Is already a reciprocated at a winding unit Thread guide, for example a belt thread guide, for production the traversing movement, the speed of which is separate is controllable from the spool speed, that can be Process according to the invention for producing a cylindrical cheese according to the invention without additional construction effort and without changing Thread guide elements through the appropriate device or programming the controller on simple Run way.

The invention also allows coarse yarns with relative at low crossing angles. For example, that is Processing of cotton yarn with Nm 20 at one Crossing angle α of 25 ° with the associated good Drainage properties and long barrel lengths are still possible. Improved drainage properties lead to a reduction in Downtimes by reducing the number of thread breaks the further processing of the bobbins. With the through the Reduction of the crossing angle increasing barrel length can be achieved that on an inventive cylindrical cheese has increased by approx. 15% to 25% Amount of yarn compared to a conventional cylindrical cheese same coil diameter is wound. this leads to a significant reduction in the number of packages one Partie. This not only reduces downtimes for changing bobbins at the spinning positions, but also the Transport effort and the transport volume during coil transport are reduced. The effort for handling the Cross-wound bobbins in subsequent yarn processing processes be lowered.

The invention improves productivity and enables Reduce costs and overall profitability of yarn production and processing.

Further details of the invention are based on the figures explained.

It shows:

Fig. 1

a side view of a spinning station for implementation of the inventive method in a simplified schematic representation,

Fig. 2

the schematic diagram of an inventive cylindrical cheese,

Fig. 3

the course of the crossing angle α over a stroke represented simply as a curve.

Figure 1 shows a winding device 1 on a cylindrical Spinning unit producing a bobbin Rotor spinning machine. The winding device 1 has a roller 2 which, by means of friction, the cylindrical cheese 3 drives. The roller 2 rotates in the direction of arrow 4. Die Cross-wound bobbin 3 is pivoted through a bobbin frame 5 supported and lies on the roller 2. The roller 2 will applied with a contact pressure. The thread 6 is in Direction of arrow 7 by means of a pair of rollers cooperating take-off rollers 8, 9 from the spin box 10 of the Spinning station with constant thread speed and via a reciprocating thread guide 11 as cylindrical winding body 12 of the package 3 wound. The thread guide 11 is part of a traversing device 13 which connected via an operative connection 14 to the motor 15 and from this is driven. The roller 2 is on the shaft 16 of driven by a motor 17. Both the motor 15 and the Motor 17 are controlled by a microprocessor 18, wherein the crossing angle α of the cylindrical cheese 3, depending from the position of the thread guide 11, during the respective Coil stroke is controllable.

The cylindrical cross-wound bobbin 3 shown in FIG. 2 shows a winding body 12 wound according to the invention on the bobbin tube 19. The winding body 12 has a cross winding with the crossing angle α _R in the edge zones 20, 21 and a cross winding with the crossing angle α _M in the central zone 22 on. In the exemplary embodiment in FIG. 2, α _{R is} 35 ° and α _M is 25 °. The width of the zone 22 and the edge zones 20, 21 is marked by a dashed line. The cylindrical winding body 12 is shown in a simplified schematic diagram, the respective course of the thread 6 being laid out being only partially indicated, but showing differently large crossing angles α. The width B _{WG of} the cheese 3 from the left bobbin edge 23 to the right bobbin edge 24 is 150 mm in the exemplary embodiment. The width B _WG corresponds to a stroke of the thread guide 11.

Due to inertial forces at the high speeds of the Traversing movement even with the relatively low mass of the Thread 6, especially with coarse threads, can be effective and by reversing the movement of the back and forth Thread guide 11 occur, the transition takes place from a value of the crossing angle α to another value not abruptly, so as shown in the schematic diagram of Figure 2, but fluently.

In this respect, the representation of FIG. 3 is the actual one
Formation of the crossing angle α of the package 3 or the course of the thread on the lateral surfaces closer than the illustration in FIG. 2. FIG. 3 shows the as
Curve 31 over the winding width B _{WG of} the cross-wound bobbin 3 shows the course of the size of the crossing angle α, the values representing the stroke of the thread guide 11 in the representation of the cylindrical bobbin 3 of FIG. 2 from left to right
(Stroke of the thread guide 11 during the forward movement) represent. At the left reversal point of the thread guide 11 or the left bobbin edge 23, the crossing angle α passes through the zero point and reaches the value of α _R = 35 ° in the left edge zone 20. The value decreases from α _R = 35 ° after a transition range to α _M = 25 °. The value of α _M = 25 ° is kept constant in the central zone 22. On the right side of the package 3, the value of α _M = 25 ° rises again to α _R = 35 ° in the right edge zone 21 and then passes through the zero point again at the right reversal point of the thread guide 11 or the right package edge 24. The width of the central zone 22, in which the crossing angle α lies at the value of α _M = 25 °, takes up the major part of the winding width B _WG . The course of the size of the crossing angle α during the stroke of the thread guide 11 in the return movement to the left is indicated by dashed lines in FIG. 3.

The setting of the crossing angle α is carried out in a manner known per se and therefore not explained in more detail here by controlling the rotational speed of the cheese 3 and the speed of the traversing movement of the thread guide 11 during the stroke. The cylindrical cross-wound bobbin 3, which is designed with a crossing angle α of α _R = 35 ° in the edge zones 20, 21, has stable bobbin edges 23, 24, without impermissibly high pressing pressure being exerted. This prevents bulges on the end faces of the cheese 3. The advantageously low crossing angle α of α _M = 25 ° in the zone 22 lying between the edge zones 20, 21 enables a longer barrel length with a stable winding body with the same finished diameter of, for example, 300 mm of the package 3, which thereby 15% to 25% more yarn contains as usual coils of the same diameter.

The running behavior of the cylindrical cheese 3 is improved by calmer thread running and the suppression of Loop formation and yarn entanglement.

The invention is not shown on the Embodiments limited. The thread guide can alternatively for example as a belt thread guide or as Grooved roll to be formed. The crossing angle α of the cylindrical cheese according to the invention can advantageously in a range of 30 ° to 40 ° in the peripheral zones 20, 21 and in the middle zone 22 in a range of 15 ° to 28 ° accept alternative values.

Claims (10)

Method for forming the winding body of a cylindrical cheese, in which the crossing angle α is changed during the travel of the coil,
characterized in that the thread guidance is carried out in such a way that a crossing angle α _{M of} less than 28 ° and greater than 15 ° is carried out in a central zone of the bobbin stroke and that in the edge zones lying towards the ends of the winding body a relative to the central zone (22nd ) enlarged crossing angle α _{R is} generated. Method according to Claim 1, characterized in that the crossing angle α _{M is formed} in the central zone (22) with a value between 20 ° and 26 °. Method according to claim 1 or 2, characterized in that in the central zone (22) the crossing angle α _{M is formed} at least 8 ° smaller than the maximum crossing angle α _R in the peripheral zones (20, 21). Method according to one of the preceding claims, characterized in that the central zone (22) occupies more than 50% of the total winding width B _WG . Method according to one of the preceding claims, characterized in that the coil contact pressure is reduced with increasing coil diameter. Method according to one of the preceding claims, characterized in that the thread tension is reduced as the bobbin diameter increases. Cross-wound bobbin with a cylindrical winding body made of rotor yarn, characterized in that the crossing angle α is formed within a yarn layer in a central zone (22) of the bobbin stroke less than 28 ° and greater than 15 ° and only in the edge zones located towards the ends of the winding body there is an increased crossing angle α _R with respect to the central zone (22). Cross-wound bobbin according to Claim 7, characterized in that the crossing angle α _M in the central zone (22) is between 20 ° and 26 °. Cross-wound bobbin according to one of claims 7 or 8, characterized in that the crossing angle α _M in the central zone (22) is at least 8 ° smaller than the maximum crossing angle α _R in the peripheral zones (20, 21). Cross-wound bobbin according to one of Claims 7 to 9, characterized in that the at least one zone (22) with a smaller crossing angle α _{M forms} more than 50% of the total winding width B _WG .

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