Rotor spinning machine and method for operating a rotor spinning machine

Abstract

The invention relates to a rotor spinning machine and a method for operating a rotor spinning machine with a control device, an open-end rotor spinning device and a feed unit feeding at least two fiber strips into the open-end rotor spinning device, which has a dissolving roller for dissolving fiber strips and a feed device with a first and a second feed roller, which can be operated independently of each other by means of the control device, for a first fiber strip and a second fiber strip.In order to provide a rotor spinning machine and a method for operating a rotor spinning machine which enables a simple adjustment of the feed speeds of the feed unit having at least two feed rollers, it is provided that the control device determines an individual feed speed of a feed roller for the production of a yarn with predetermined yarn properties from a single fiber strip fed by means of one feed roller and coordinates a first feed speed of the first feed roller and a second feed speed of the second feed roller such that the sum of the first and second feed speeds corresponds to the individual feed speed.

Description

[0001] The invention relates to a rotor spinning machine and a method for operating a rotor spinning machine with a control device, an open-end rotor spinning device and a feed unit feeding at least two fiber slivers into the open-end rotor spinning device, the an opening roller for opening fiber slivers and a feed device with a first and a second feed roller, which can be operated independently of one another by means of the control device, for a first fiber sliver and a second fiber sliver has.

[0002] Rotor spinning machines with two independently operable feed rollers or feed roller sections of a single feed roller, as well as methods for operating them, are known in a variety of designs from the prior art. Such rotor spinning machines enable the feeding of two different or two identical spinning materials into the open-end rotor spinning device, which allows, for example, the production of so-called fancy yarns that exhibit, for example, a variation in thickness or color. State-of-the-art spinning machines are known from CN205635925U, JPS5039183B1, and CH562337A5.

[0003] The determination of the spinning parameters, such as the yarn take-off speed, the rotor speed and the first and second feed speeds of the first and second feed rollers for producing a uniform yarn with specified yarn parameters is only possible with considerable effort.

[0004] Based on this, the invention is based on the object of providing a rotor spinning machine and a method for operating a rotor spinning machine, which enables a simple adjustment of the feed speeds of the feed unit having at least two feed rollers.

[0005] The invention solves the problem by a method for operating a rotor spinning machine having the features of claim 1 and by a rotor spinning machine having the features of claim 5. Advantageous developments of the invention are specified in the dependent claims.

[0006] According to the method according to the invention, the control device first determines, after specifying the yarn properties of the yarn to be produced, e.g., by inputting the yarn parameters by the operating personnel via a control unit, the individual feed speed that would be required to produce the specified yarn using only one feed roller that feeds only a single fiber sliver to the open-end rotor spinning device. The individual feed speed is thus the feed speed that would be required to produce a specified yarn using a feed unit with only one feed roller.

[0007] This individual feed speed is used in the control device to set the first feed speed of the first feed roller and the second feed speed of the second feed roller, namely in such a way that the control device coordinates the first feed speed and the second feed speed in such a way that their sum corresponds to the previously determined individual feed speed. If the first feed speed is changed, for example by the operator, the control device automatically adjusts the second feed speed in such a way that the sum of the first and second feed speeds again corresponds to the previously determined individual feed speed. The operating personnel thus has the option of adjusting the proportion of fiber slivers fed to the open-end rotor spinning device without causing irregularities in the yarn to be produced.When two similar fiber slivers are fed in, mass fluctuations in the spun fiber mass are also prevented, so that a consistently uniform yarn can be produced.

[0008] The method according to the invention is characterized in that the spinning parameters, in particular the individual feed speed, can be determined simply and reliably in a known manner. This individual feed speed forms the basis for the operation of the feed unit with at least two feed rollers, wherein the ratio of the feed speeds of the individual feed rollers is coordinated by the control device such that this together corresponds to 100% of the individual feed speed. In a feed unit having two feed rollers, an increase in the feed speed of the first feed roller leads to a reduction in the feed speed of the second feed roller. The ratio of the feed speeds to one another represents a further spinning parameter, which can be set, for example, by the operating personnel via an operating unit connected to the control device.

[0009] The number of yarn parameters used to determine the individual feed speed is, in principle, freely selectable. However, according to a particularly advantageous embodiment of the invention, the control device detects the twist, draft, and / or yarn count of the yarn being produced to determine the individual feed speed. Taking into account a large number of yarn parameters makes it possible to use the control device to determine the spinning parameters, for example, the rotor speed representing the reference variable, as well as the speed of the yarn take-off and the individual feed speed, with particular precision as the basis for setting the feed speed of the first and second feed rollers.

[0010] According to a further embodiment of the invention, it is provided that the control device further detects the fiber sliver numbers of the fiber slivers to be fed in, which additionally increases the quality of the yarn to be produced.

[0011] The determination of the individual feed speed based on the specified yarn properties can, in principle, be carried out in any desired manner. However, according to a particularly advantageous embodiment of the invention, the control device calculates the individual feed speed based on the specified yarn properties or retrieves it from a database. The individual feed speed can be reliably determined in a simple manner using proven methods. Furthermore, sufficient data is available to determine the individual feed speed, i.e., the feed unit with only one feed roller, to make it easily available for retrieval in a database.

[0012] A characteristic of the rotor spinning machine according to the invention is that the control device is designed to determine an individual feed speed of a feed roller for producing a yarn with predetermined yarn properties from only a single fiber sliver fed by means of only one feed roller. Based on this individual feed speed, the control device is further designed to set a first feed speed of the first feed roller and a second feed speed of the second feed roller such that the sum of the first and second feed speeds corresponds to the individual feed speed.

[0013] The rotor spinning machine according to the invention is characterized in that the individual feed speed required to produce the specified yarn can be determined particularly easily by means of the control device. This speed is used in the control device to set the feed speed of the individual feed rollers, with the control device coordinating the feed speeds such that their sum corresponds to the individual feed speed. Adjustments to one of the feed roller feed speeds, e.g., by the operating personnel, thus automatically lead to a corresponding adjustment of the feed speed of the other feed roller by the control device, such that the sum of the feed speeds corresponds to the individual feed speed previously determined by the control device.

[0014] The rotor spinning machine according to the invention thus allows the operating personnel to make adjustments to the fiber sliver feed in a particularly simple manner without affecting the uniformity of the yarn to be produced.

[0015] According to a further development of the invention, the control device is connected to an operating device for data input. The operating unit thus enables the operating personnel to conveniently enter the yarn parameters of the yarn to be produced, so that the spinning parameters can be determined by the control device. The operating unit also enables the machine operator to adjust the speed of the individual feed rollers, with the control device then automatically adjusting the non-adjusted feed roller accordingly.

[0016] To determine the individual feed speed, the control unit is connected to a computing unit and / or a database. The computing unit enables the mathematical determination of the individual feed speeds in a known and proven manner. The use of a database allows the control unit to query the spinning parameters based on the yarn parameters of the yarn to be produced, either alternatively or in addition.

[0017] The invention is explained below with reference to the drawings. In the drawings: Fig. 1 shows a perspective view of an open-end rotor spinning machine having several workstations and Fig. 2 shows a schematic view of a feed unit with two feed rollers.

[0018] Figure 1shows in a perspective view an embodiment of a rotor spinning machine 1, with a central control unit 8, which is equipped with a control device 9 designed according to the invention. Rotor spinning machines are known to have a plurality of work stations 2, each of which is equipped, among other things, with an open-end rotor spinning device 3 and a winding device 4. For feeding fibers into the open-end rotor spinning device 3, the individual work stations 2 each have a feed unit 11, which is subsequently Figure 2 is shown.

[0019] The workstations 2 of the rotor spinning machine 1 are supplied by service units 5. These serve, for example, to exchange a finished cross-wound bobbin 7 for a fresh empty tube at the workstations 2.

[0020] As is known and therefore not explained in detail, in the open-end rotor spinning devices 3 of the workstations 2 of the rotor spinning machine 1, two fiber slivers 12, 13, which are stored in spinning cans 6 and on bobbins 27, are spun into a yarn with predetermined yarn properties, which are then wound into cross-wound bobbins on the winding devices 4. To control the rotor spinning machine 1 and the individual workstations 2, the rotor spinning machine 1 has the central control unit 8, which is equipped with a control device 9 designed according to the invention. Via an operating unit 10, the system operator has the option of entering yarn parameters of the yarn to be produced as well as reading and changing spinning parameters.

[0021] The control device 9 also serves to control the schematically shown Figure 2The feed unit 11 shown here is for feeding fibers from at least two fiber slivers 12, 13 into the open-end rotor spinning device 3. The feed unit 11 has two feed rollers 16, 17, each driven separately by the control device 9, for feeding fiber slivers 12, 13, as well as an opening roller 14 for separating the fiber slivers 12, 13 into individual fibers. The rotational axis 15 of the feed rollers 16, 17 and the rotational axis (not shown) of the opening roller 14, which is only shown in sections, run parallel to one another.

[0022] The feed rollers 16, 17 have a first roller section 18 and a second roller section 19, each of which is designed to feed a fiber sliver 12, 13. Both roller sections 18, 19 are identical to one another and, in particular, have an identical shape and size. To facilitate the unwinding of the supplied fiber sliver 12, 13, both roller sections 18, 19 each have a linear profile.

[0023] The first feed roller 16 and the second feed roller 17 can be driven separately from one another via drives not shown here via the control device 9. To determine the feed speeds of the first feed roller 16 and the second feed roller 17, the control device 9 first records yarn parameters of a yarn to be produced, in particular the draft, twist, yarn count, and sliver count of a sliver to be fed. Based on this, the control device 9 determines the required individual feed speed of the individual feed rollers 16, 17 for a feed unit 11 having only one feed roller 16, 17 for feeding a sliver 12, 13. This individual feed speed serves the control device 9 as a reference value for controlling the two feed rollers 16, 17 of the feed unit 11.The sum of the feed speeds of the two feed rollers 16, 17 corresponds to the individual feed speed previously determined by the control device 9. The control device 9 increases or decreases the feed speed of the other feed roller 16, 17 in proportion to the decrease or increase in the feed speed of one feed roller 16, 17 by the operating personnel.

[0024] To ensure secure feeding of the fiber slivers 12, 13 to the feed rollers 16, 17 and reliable transport by the feed rollers 16, 17, a guide element 20 with a feed section 21 is arranged in the feed direction of the feed rollers 16, 17, wherein the feed section 21 is flat and has a feed trough 22 opposite the feed rollers 16, 17 and lowered into the plane of the feed section 21. Between the feed trough 22 and the feed rollers 16, 17 there is a gap 23 in which the fiber slivers 12, 13 are transported to the rotating feed rollers 16, 17.

[0025] In the feed section 21, directly in front of the feed rollers 16, 17, a guide housing 24 is arranged, which surrounds each of the two fiber slivers 12, 13 fed to one of the roller sections 18, 19 on three sides, so that together with the flat surface of the feed section 21 as the fourth side, a closed guide tunnel 25, 26 is formed for each of the two fiber slivers 12, 13. The first guide tunnel 25 is longer than the second guide tunnel 26 so that the first fiber sliver 12 fed from the underside of the guide element 20 from a sliver can 6 cannot come into contact with the second fiber sliver 13 fed from the top side of the guide element 20 from a spool 27, whereby a completely independent feed of both fiber slivers 12, 13 is achieved.

[0026] Finally, the integrally formed guide element 20 has an opening roller section 28 following the feed trough 22, which extends in sections along the direction of rotation of the opening roller 14 at a constant distance along the surface of the opening roller 14. The space formed between the opening roller section 28 and the surface of the opening roller 14 ensures that the fiber slivers 12, 13 fed by the feed rollers 16, 17 are reliably separated into individual fibers on the surface of the opening roller 14. List of reference symbols

[0027] 1 Rotor spinning machine 2 Workstations 3 Open-end rotor spinning device 4 Bobbin device 5 Service unit 6 Spinning can 7 Cross-wound bobbin 8 Central control unit 9 Control unit 10 Operating unit 11 Feed unit 12 Sliver 13 Sliver 14 Opening roller 15 Rotation axis 16 Feed roller 17 Feed roller 18 First roller section 19 Second roller section 20 Guide element 21 Feed section 22 Feed trough 23 Gap 24 Guide housing 25 Guide tunnel 26 Guide tunnel 27 Bobbin 28 Opening roller section

Claims

1. A method for operating a rotor spinning machine (1) with a control device (9), an open-end rotor spinning device (3) and a supply unit (11) that feeds at least two fiber slivers (12, 13) into the open-end rotor spinning device (3) and has - an opening roller (14) for opening fiber slivers (12, 13) and - a feed apparatus having a first and a second feed roller (16, 17), which can be operated independently of one another by means of the control device (9), for a first fiber sliver (12) and a second fiber sliver (13), characterized in that the control device (9) - determines an individual drafting speed of one feed roller (16, 17) which would be required to produce a yarn with predetermined yarn properties from a single fiber sliver (12, 13) fed by means of the one feed roller (16, 17) and - coordinates a first drafting speed of the first feed roller (16) and a second drafting speed of the second feed roller (17) with one another in such a way that the sum of the first and second drafting speeds corresponds to the individual drafting speed.

2. The method according to claim 1, characterized in that the control device (9) detects the twist, the draft and / or the yarn number of the yarn to be produced in order to determine the individual drafting speed.

3. The method according to either claim 1 or claim 2, characterized in that the control device (9) detects the fiber sliver numbers of the fiber slivers (12, 13) to be fed in.

4. The method according to one or more of the preceding claims, characterized in that the control device (9) calculates the individual drafting speed on the basis of the predetermined yarn properties or retrieves it from a database.

5. A rotor spinning machine (1) with a control device (9), an open-end rotor spinning device (3) and a supply unit (11) that feeds at least two fiber slivers (12, 13) into the open-end rotor spinning device (3) and has - an opening roller (14) for opening fiber slivers (12, 13) and - a feed apparatus having a first and a second feed roller (16, 17), which can be operated independently of one another by means of the control device (9), for a first fiber sliver (12) and a second fiber sliver (13), characterized in that the control device (9) is designed - to determine an individual drafting speed of one feed roller (16, 17) which would be required to produce a yarn with predetermined yarn properties from a single fiber sliver (12, 13) fed by means of the one feed roller (16, 17) and - to set a first drafting speed of the first feed roller (16) and a second drafting speed of the second feed roller (17) such that the sum of the first and second drafting speeds corresponds to the individual drafting speed.

6. The rotor spinning machine (1) according to claim 5, characterized in that the control device (9) is connected to an operating unit (10) for data input.

7. The rotor spinning machine (1) according to claim 5 or 6, characterized in that the control device (9) is connected to a computing unit and / or a database.

Images