Spinning station of a spinning preparation machine

Abstract

A spinning preparation machine for producing a roving from a fiber bundle includes a vortex chamber having an infeed opening for the fiber bundle and a yarn forming element extending at least partially into the vortex chamber. The spinning station includes spin nozzles, which lead into the vortex chamber in the region of a wall enclosing the vortex chamber and via which air is introduced into the vortex chamber in a specified direction of rotation in order to set the fiber bundle, which is fed in a transport direction, into rotation in the region of an inlet mouth of the yarn forming element. The yarn forming element includes a draw-off channel, which adjoins the inlet mouth and via which the yarn can be drawn out of the vortex chamber. The wall of the vortex chamber has a transition section, which adjoins the infeed opening, and has the shape of the circumferential surface of a truncated cone, and the diameter of which increases in the transport direction. The spin nozzles lead into the vortex chamber in the region of the transition section and each has a direction of flow that is oriented in the direction of an outer surface of the wall enclosing the vortex chamber.

Claims

1. A spinning station of a spinning preparation machine for producing a roving from a fiber bundle, comprising: a vortex chamber having an infeed opening for the fiber bundle fed in a transport direction of the fiber bundle; a roving forming element extending into the vortex chamber and having an inlet mouth; spin nozzles in a wall enclosing the vortex chamber and directed into the vortex chamber via which air is introduced into the vortex chamber in a specified direction of rotation in order to set the fiber bundle into rotation in the region of the inlet mouth of the yarn forming element; the roving forming element further comprising a draw-off channel that adjoins the inlet mouth via which the roving is drawn out of the vortex chamber; the wall of the vortex chamber comprising a transition section that adjoins the infeed opening and has the shape of a circumferential surface of a truncated cone, and a diameter that increases in the transport direction; wherein the spin nozzles lead into the vortex chamber in the transition section and each have a direction of flow that is oriented towards the wall enclosing the vortex chamber.

2. The spinning station according to claim 1, wherein the transition section transitions into a cylindrical section in the transport direction of the fiber bundle.

3. The spinning station according to claim 1, wherein in a view extending parallel to a longitudinal axis of the draw-off channel, each spin nozzle has a longitudinal axis that defines an angle with the longitudinal axis of the draw-off channel between 75 degrees and 40 degrees.

4. The spinning station according to claim 1, wherein a circumferential line of the transition section viewed in a longitudinal direction defines an angle with a longitudinal axis of the draw-off channel between 80 degrees and 15 degrees.

5. The spinning station according to claim 1, wherein in a sectional view extending perpendicular to a longitudinal axis of the draw-off channel, the spin nozzles extend between the longitudinal axis of the draw-off channel and a tangent line of the wall of the vortex chamber.

6. The spinning station according to claim 1, wherein the transition section has a diameter on a side facing the infeed opening between 14 mm and 8 mm.

7. The spinning station according to claim 6, wherein the transition section has a diameter on a side opposite the infeed opening between 16 mm and 10 mm.

8. The spinning station according to claim 1, wherein the transition section merges into a cylindrical section in the transport direction, and the yarn forming element has a cylindrical outer contour in the region of the cylindrical section.

9. The spinning station according to claim 8, wherein the yarn forming element has an outer diameter at the cylindrical outer contour between 5 mm and 14 mm.

10. The spinning station according to claim 1, wherein the inlet mouth through which roving is pulled out of the vortex chamber has a diameter between 4 mm and 12 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages of the invention are described in the following exemplary embodiments, in which:

(2) FIG. 1 shows a schematic view of a spinning preparation machine;

(3) FIG. 2 shows a schematic sectional illustration of a part of a spinning station, cut along the sectional surface B-B in FIG. 3;

(4) FIG. 3 shows a schematic sectional illustration of a part of a spinning station, cut along the sectional surface A-A in FIG. 2;

(5) FIG. 4 shows a schematic sectional illustration of the part F in FIG. 2, cut along the sectional surface C-C in FIG. 3;

(6) FIG. 5 shows a schematic sectional illustration of a part of a spinning station according to the invention, cut along the sectional surface H-H in FIG. 8;

(7) FIG. 6 shows a part of a sectional illustration of a spinning station according to the invention represented by the line K in FIG. 5, cut along the sectional surface H-H in FIG. 8;

(8) FIG. 7 shows a schematic sectional illustration of the part K in FIG. 5, cut along the sectional surface G-G in FIG. 8;

(9) FIG. 8 shows a schematic sectional illustration of a part of a spinning station according to the invention, cut along the sectional surface J-J in FIG. 5;

(10) FIG. 9 shows a view corresponding to FIG. 6, with the addition of an angular dimension;

(11) FIG. 10 shows a view corresponding to FIG. 7, with the addition of an angular dimension; and

(12) FIGS. 11 through 13 show views corresponding to FIG. 6, with the addition of various dimensions.

DETAILED DESCRIPTION

(13) Reference will now be made to embodiments of the invention, one or more examples of which are shown in the drawings. Each embodiment is provided by way of explanation of the invention, and not as a limitation of the invention. For example features illustrated or described as part of one embodiment can be combined with another embodiment to yield still another embodiment. It is intended that the present invention include these and other modifications and variations to the embodiments described herein.

(14) First, it should be expressly noted that the illustrated parts of various spinning stations 1 and the upstream and downstream elements in FIG. 1 are not drawn to scale. Instead, the individual figures merely show schematic illustrations, which are intended to elucidate the basic design of the respective assemblies. In particular, the spacings, angles, and diameters that are indicated, in part, in the respective figures have values in the drawings that do not necessarily represent the most advantageous ranges.

(15) FIG. 1 shows a schematic view of a part of a spinning preparation machine. The spinning preparation machine may, if necessary, comprise a drafting system 22, to which there is fed a fiber bundle 3, for example in the form of a doubled sliver. The illustrated spinning preparation machine also comprises, in principle, a spinning station 1, which is spaced apart from the drafting system 22 and has an internal vortex chamber 4, in which the fiber bundle 3 and/or at least a portion of the fibers of the fiber bundle 3 are provided with a protective twist (the exact mode of operation of the spinning station 1 is described in greater detail in the following).

(16) The spinning preparation machine can also comprise a pair of draw-off rollers 21 and a winding device 20 (also schematically illustrated) for the roving 2, which is disposed downstream of the pair of draw-off rollers 21. The device according to the invention does not necessarily have to comprise a drafting system 22 as shown in FIG. 1. The pair of draw-off rollers 21 is not absolutely necessary either.

(17) The spinning preparation machine operates according to a special air-jet spinning process. In order to form the roving 2, the fiber bundle 3 is guided in a transport direction T via an infeed opening 5 of a fiber guide element 19 (which is preferably designed as a separate component) into the vortex chamber 4 of the spinning station 1. There it receives a protective twist, i.e., at least a portion of the fibers of the fiber bundle 3 is captured by an airflow that is generated by appropriately placed spin nozzles 7. A portion of the fibers is thereby pulled at least a little way out of the fiber bundle 3 and is wound around the tip of a yarn forming element 6, which protrudes into the vortex chamber 4.

(18) In terms of the spin nozzles 7, it is mentioned here merely as a precautionary measure that these should be typically oriented such that a unidirectional airflow having a uniform direction of rotation is generated. In this connection, the individual spin nozzles 7 are preferably disposed with rotational symmetry relative to one another (see FIG. 3, which shows a sectional illustration along the sectional surface A-A in FIG. 2, wherein the spin nozzles 7, the greater part of which extends above the sectional surface and therefore cannot actually be seen, are illustrated using dashed lines). In terms of all the exemplary embodiments shown, it is should also be noted that the spin nozzles 7 each have a direction of flow that is oriented in the direction of a wall 8 enclosing the vortex chamber 4 such that the generated airflow extends at least largely in the form of a spiral between the outer surface 12 of the yarn forming element 6 and the wall 8 of the vortex chamber 4.

(19) Finally, the fibers of the fiber bundle 3 are drawn out of the vortex chamber 4 via an inlet mouth 9 of the yarn forming element 6 and a draw-off channel 10, which is disposed inside the yarn forming element 6 and adjoins the inlet mouth 9. In doing so, the free fiber ends are finally also drawn on a helical trajectory in the direction of the inlet mouth 9 and wrap as wrapping fibers around the centrally extending fibers, resulting in a roving 2 which has the desired protective twist.

(20) Due to the only partial twisting of the fibers, the roving 2 has a (residual) draftability which is essential for the further processing of the roving 2 in a downstream spinning machine, for example a ring spinning machine. Conventional air-jet spinning devices, on the other hand, give the fiber bundle 3 such a pronounced twist that the required drafting following the yarn production is no longer possible. This is also desired in this case since conventional air-jet spinning machines are designed to produce a finished yarn, which is generally intended to be characterized by high strength.

(21) The spinning station 1 according to the invention also preferably has a twist-jamming element, which is inserted into the fiber guide element 19, for example. This can be designed as a fiber delivery edge, as a pin, or as another embodiment known from the prior art, and prevents the propagation of a rotation in the fiber bundle 3 opposite the delivery direction of the fiber bundle 3 and, therefore, in the direction of the inlet opening 5 of the fiber guide element 19.

(22) As can now be seen from FIGS. 2 to 4 (FIG. 4 shows a sectional illustration of the region F in FIG. 2 along the sectional surface C-C in FIG. 3), the spin nozzles 7 lead into the vortex chamber 4 in the region of an annular edge 23. Such a geometry is not optimal for the airflow generated by means of the spin nozzles 7, however. The respective outlet openings of the individual spin nozzles 7 transition into the annular edge 23 on both sides, thereby forming a certain stepped transition here. In addition, an upward or downward displacement (as viewed in FIG. 2) of the utilized boring tool that occurs during the production of the spin nozzles 7 results in a change in the flow field of the airflow.

(23) In order to counteract these disadvantages, it is now proposed according to the invention that the wall 8 of the vortex chamber 4 has a transition section 11 adjacent to the infeed opening 5, the shape of which corresponds to the circumferential surface of a truncated cone. Such a design can be seen in the exemplary embodiments according to FIGS. 5 to 13.

(24) As can be seen, for example, from FIGS. 6 (corresponds to a sectional illustration along the sectional surface H-H in FIG. 8) and 7 (corresponds to a sectional illustration along the sectional surface G-G in FIG. 8), it is advantageous when the transition section 11 is designed as a conical annular section. The dimensions of the transition section 11 should be sized such that the air outlet openings of the spin nozzles 7, which are adjacent to the vortex chamber 4, transition into the transition section 11 on all sides. A displacement of the boring tool, which is typically used to produce the spin nozzles 7, does not significantly affect the flow field of the generated airflow in this case.

(25) Moreover, it can be advantageous in general when the transition section 11 transitions into a cylindrical section 13 of the wall 8 of the vortex chamber 4 in the transport direction T. If at least a part of the outer surface 12 of the yarn forming element 6 also has a cylindrical outer contour 18 (see FIG. 6, for example), the vortex chamber 4 has a region adjoining the transition section 11 that has a consistent flow cross-section, which also has a favorable effect on the swirled airflow that is generated.

(26) Independently thereof, FIG. 8 shows that the spin nozzles 7 do not necessarily need to lead tangentially into the vortex chamber 4 (as shown in FIG. 3). Rather, it can be advantageous when the spin nozzles 7 extend so as to be spaced apart from a corresponding tangent line 17, wherein a spin nozzle 7 and a tangent line 17 can extend parallel to one another in each case in the top view shown in FIG. 8 (for the rest, the spin nozzles 7 are indicated with dashed lines in FIG. 8 for explanatory purposes, although they would not actually be seen in the corresponding sectional view; refer to the details provided for FIGS. 2 and 3 for comparison).

(27) Finally, suitably oriented spin nozzles 7 generate an airflow, which does not flow tangentially along the wall 8 of the vortex chamber 4 immediately after it emerges from the respective spin nozzle 7. Rather, it is advantageous when the spin nozzles 7 and, therewith, the generated airflow are oriented in the direction of the wall 8 of the vortex chamber 4 and, therefore, also in the direction of the gap, which is present between the outer surface 12 of the yarn forming element 6 and the wall 8 of the vortex chamber 4.

(28) Finally, advantageous dimensions or angles of spinning stations 1 according to the invention can be seen from the parts that are shown in FIGS. 9 to 13 (wherein it should be expressly noted that the fact that portions of the illustrations are identical does not mean that all the values mentioned in the following must be realized simultaneously).

(29) An airflow that is advantageous for the draftability of the roving 2 results when the angle (see FIG. 9) between the circumferential line 16 of the transition section 11 and the longitudinal axis 15 of the draw-off channel 10 has a value between 80 and 15, wherein the value should advantageously be between 40 and 20. In particular, it has been shown that an angle of 30 results in an airflow with which a roving 2 can be generated, which has a strength despite the desired draftability that permits the roving 2 to be transported further to a downstream spinning machine.

(30) It is also advantageous when the longitudinal axis 14 of each spin nozzle 7 encloses an angle (see FIG. 10) with the longitudinal axis 15 of the draw-off channel 10 in a section extending parallel to the respective longitudinal axis 14 and parallel to the longitudinal axis 15 of the draw-off channel 10, said angle having a value between 75 and 40. A value between 70 and 50 has proven to be particularly advantageous, wherein, in particular, a value of 60 yields an excellent result in terms of strength and draftability of the roving 2.

(31) In this context, it should finally be noted that it is advantageous when the sum of the two angles and yields a value that deviates from 90 as little as possible (a value of 90 is preferred).

(32) In addition, it was recognized that the selection of the spacings labeled in FIGS. 11 to 13 also influences the quality of the roving 2 produced by means of the respective spinning station 1. The following values have proven to be advantageous in this context: Diameter of the transition section 11 on the side thereof facing the infeed opening 5 of the vortex chamber 4 (=D1): between 8 mm and 14 mm, preferably between 9 mm and 12 mm, particularly preferably 10 mm Diameter of the transition section 11 on the side thereof facing away from the infeed opening 5 of the vortex chamber 4 (=D2): between 10 mm and 16 mm, preferably between 11 mm and 14 mm, particularly preferably 12.5 mm Outer diameter of the yarn forming element 6 in the region in which it has a cylindrical outer contour 18 (=D3): between 5 mm and 14 mm, preferably between 10 mm and 11.5 mm Diameter of the inlet mouth 9 of the draw-off channel 10 in the region of the vortex chamber 4 (=D4): between 4 mm and 12 mm, preferably between 6 mm and 8 mm.

(33) Finally, it should be noted that the present invention is not limited to the exemplary embodiments that have been shown and described. Modifications within the scope of the patent claims are also possible, as is any combination of the features, even if they are shown and described in different exemplary embodiments or the general description of the advantages.