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, the rotor spinning machine having a control device, a free-end rotor spinning device and a supply unit for feeding at least two fiber strands into the free-end rotor spinning device, the supply unit having: an opening roller for opening the fiber strands; and a feeding device for a first fiber strand and a second fiber strand with a first feeding roller and a second feeding roller which can be operated independently of one another using the control device. To provide a rotor spinning machine and a method for operating a rotor spinning machine which make it easy to set the draft speed of a supply unit having at least two feeding rollers, it is provided that the control device: determines a separate draft speed for producing a yarn with predetermined yarn properties from a single fiber strand fed using the first feeding roller; and coordinates the first draft speed of the first feeding roller and the second draft speed of the second feeding roller with one another in such a way that the sum of the first draft speed and the second draft speed corresponds to the separate draft speed.

Description

[0001] This invention relates to a rotor spinning machine and a method for operating the rotor spinning machine, the rotor spinning machine having a control device, a free-end rotor spinning device, and a supply unit that feeds at least two fiber slivers into the free-end rotor spinning device and has

[0002] - Opening roller, which is used to open fiber slivers, and

[0003] - A feeding device for a first fiber sliver and a second fiber sliver, the feeding device having a first feed roller and a second feed roller, the first feed roller and the second feed roller being operable independently of each other using a control device. Rotor spinning machines with feed roller sections that can be operated independently of each other, either with two feed rollers or a single feed roller, and methods for operating such machines are known in various embodiments from the prior art.

[0004] This type of rotor spinning machine enables the feeding of two different or two identical spinning materials into the free-end rotor spinning device, thereby producing, for example, so-called fancy yarns, which have variations in thickness or color.

[0005] It takes considerable effort to determine the spinning parameters (such as yarn draw speed, rotor rotation speed, and the first and second drafting speeds of the first and second feed rollers) used to produce uniform yarns with predetermined yarn parameters.

[0006] Therefore, the objective of this invention is to provide a rotor spinning machine that allows for easy setting of the drafting speed of a supply unit having at least two feed rollers, and a method for operating the rotor spinning machine.

[0007] The present invention achieves its objective through a method for operating a rotor spinning machine with the features of claim 1 and through a rotor spinning machine with the features of claim 5. Advantageous further embodiments of the invention are given in the dependent claims.

[0008] According to the method of the invention, the control equipment first determines a separate drafting speed after specifying the yarn characteristics of the yarn to be produced (e.g., by an operator inputting yarn parameters via an operating unit). This separate drafting speed will be required for producing the specified yarn using only one feed roller (which feeds only one single fiber sliver to the free-end rotor spinning device). Therefore, the separate drafting speed will be the drafting speed required for producing the specified yarn using a supply unit with only one feed roller.

[0009] This individual drafting speed serves as the basis in the control device for setting the first drafting speed of the first feed roller and the second drafting speed of the second feed roller, i.e., in a way that the control device matches the first and second drafting speeds to each other (so that their sum corresponds to the previously determined individual drafting speed). For example, when there is a change in the first drafting speed performed by the operator, the control unit automatically adjusts the second drafting speed so that the sum of the first and second drafting speeds again corresponds to the previously determined individual drafting speed. Therefore, the operator has the possibility of adjusting the proportion of fiber slivers supplied to the free-end rotor spinning equipment without irregular portions in the yarn to be produced. Furthermore, when two identical fiber slivers are supplied, quality fluctuations in the spun fibers are prevented, enabling the production of continuous and uniform yarn.

[0010] The method according to the invention is characterized by the ability to easily and reliably determine spinning parameters, particularly individual drafting speeds, in a familiar manner. These individual drafting speeds are based on the operation of a supply unit with at least two feed rollers, wherein the relationship between the drafting speeds of the individual feed rollers is matched to each other by a control device in such a way that they together correspond to 100% of the individual drafting speed. In a supply unit with two feed rollers, an increase in the drafting speed of the first feed roller results in a decrease in the drafting speed of the second feed roller. The relationship between these drafting speeds represents another spinning parameter, which can be set, for example, by an operator via an operating unit connected to the control device.

[0011] In principle, the number of potential yarn parameters used to determine individual drafting speeds can be freely chosen. However, according to a particularly advantageous embodiment of the invention, the control device used to determine individual drafting speeds is specified to detect the rotation, drafting, and / or quantity of the yarn to be produced. Considering multiple yarn parameters allows the control device to determine spinning parameters (e.g., rotor rotation speed as a reference variable, as well as the yarn take-off speed and individual drafting speed) in a particularly precise manner as the basis for setting the drafting speeds of the first and second feed rollers.

[0012] According to another embodiment of the invention, the control equipment is provided to further detect the number of fiber slivers to be fed, which complementarily improves the quality of the yarn to be produced.

[0013] The determination of individual drafting speeds based on predetermined yarn characteristics can, in principle, be performed in any desired manner. However, according to a particularly advantageous embodiment of the invention, the control device is specified to calculate the individual drafting speed based on predetermined yarn characteristics, or to retrieve the individual drafting speed from a database. Individual drafting speeds can be reliably determined in a simple manner using proven methods. Sufficient data also exists for determining individual drafting speeds (i.e., the individual drafting speed of a supply unit with only one feed roller), such data can be easily and retrievably set in a database.

[0014] The rotor spinning machine according to the invention is characterized in that the control device is designed to determine a single drafting speed of a feed roller, which is used to produce yarn with predetermined yarn properties from a single monofiber sliver supplied using only one feed roller. Based on this single drafting speed, the control device is further configured to set a first drafting speed of the first feed roller and a second drafting speed of the second feed roller in such a way that the sum of the first drafting speed and the second drafting speed corresponds to the single drafting speed.

[0015] The rotor spinning machine according to the invention is characterized by the fact that the individual drafting speed required for producing a given yarn can be determined in a particularly simple manner using a control device. This is based on the setting of the drafting speed of the individual feed rollers in the control device, wherein the control device adjusts the drafting speeds to each other in such a way that their sum corresponds to the individual drafting speed. Thus, the adjustment of one drafting speed of the feed rollers (e.g., by an operator) in an automated manner by the control device, such that the sum of the drafting speeds corresponds to the individual drafting speed previously determined by the control device, results in a corresponding adjustment of the drafting speed of the other feed roller.

[0016] Therefore, the rotor spinning machine according to the invention allows the operator to make adjustments to the fiber sliver feed in a particularly simple manner without affecting the uniformity of the yarn to be produced.

[0017] According to the invention, the control device is connected to the operating device for data input. The operating unit thus allows the operator to conveniently input 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 allows the machine operator to adjust the speed of individual feed rollers, wherein corresponding adjustments to unadjusted feed rollers are then automatically performed by the control device.

[0018] To determine individual drafting speeds, the control device is connected to a computing unit and / or a database. The computing unit enables the calculation and determination of individual drafting speeds in a known and verified manner. The use of the database allows the control device to optionally or additionally query spinning parameters based on the yarn parameters of the yarn to be produced.

[0019] The invention will be explained below with reference to the accompanying drawings. In the drawings:

[0020] Figure 1 A perspective view of a free-end rotor spinning machine with multiple workstations is shown, and

[0021] Figure 2 A schematic diagram of a supply unit with two feed rollers is shown.

[0022] Figure 1 A perspective view of an exemplary embodiment of a rotor spinning machine 1 is shown, the rotor spinning machine having a central control unit 8 equipped with a control device 9 designed according to the present invention. It is known that rotor spinning machines have multiple workstations 2, each workstation being equipped with a free-end rotor spinning device 3 and a winding device 4, etc. In order to feed fibers into the free-end rotor spinning device 3, each individual workstation 2 has the following... Figure 2 The supply unit 11 is shown in the figure.

[0023] The workstation 2 of the rotor spinning machine 1 is supplied by service units 5. These service units are used, for example, at workstation 2 to replace the completed cross-wound bobbin 7 with a new empty bobbin.

[0024] As is known and therefore not explained in detail, in the free end of the rotor spinning device 3 at the workstation 2 of the rotor spinning machine 1, two fiber slivers 12, 13 stored in the spinning tank 6 and on the winding tube 27 are spun into a yarn with predetermined yarn characteristics, which is then wound into a package on the winding device 4. To control the rotor spinning machine 1 and the separate workstation 2, the rotor spinning machine 1 has a central control unit 8 equipped with a control device 9 designed according to the present invention. The system operator can input the yarn parameters of the yarn to be produced and read and modify the spinning parameters via the operation unit 10.

[0025] Control device 9 is also used for control Figure 2The supply unit 11, schematically shown, feeds fibers from at least two fiber slivers 12, 13 into the free-end rotor spinning apparatus 3. In this case, the supply unit 11 comprises: two feed rollers 16, 17, which can be driven independently of each other by a control device 9 to supply the fiber slivers 12, 13; and an opening roller 14 for separating the fiber slivers 12, 13 into individual fibers. The rotation axes 15 of the feed rollers 16, 17 and the rotation axis (not shown), of the opening roller 14 (shown only partially), extend parallel to each other.

[0026] Feed rollers 16 and 17 have a first roller section 18 and a second roller section 19, each configured to supply fiber slivers 12 and 13. Roller sections 18 and 19 are formed identically to each other and, in particular, have the same shape and dimensions. To better convey the supplied fiber slivers 12 and 13, roller sections 18 and 19 each have a linear profile.

[0027] The first feed roller 16 and the second feed roller 17 can be driven independently of each other via a driver (not shown) through the control device 9. To determine the drafting speed of the first feed roller 16 and the second feed roller 17, the control device 9 first detects the yarn parameters of the yarn to be produced, specifically drafting, twist, yarn quantity, and the quantity of fiber slivers to be supplied. Based on this, for a supply unit 11 having only one feed roller 16, 17 for supplying fiber slivers 12, 13, the control device 9 determines the necessary individual drafting speed for each feed roller 16, 17. This individual drafting speed serves as a reference variable for controlling the two feed rollers 16, 17 of the supply unit 11. The sum of the drafting speeds of the two feed rollers 16, 17 corresponds to the individual drafting speed previously determined by the control device 9. In relationships where the drafting speed of the feed rollers 16, 17 is decreased or increased by the operator, the control device 9 increases or decreases the drafting speed of the other feed roller 16, 17.

[0028] To ensure the safe supply of fiber slivers 12 and 13 to the feed rollers 16 and 17 and their reliable transport, guide elements 20 with supply sections 21 are arranged in the feeding direction of the feed rollers 16 and 17. The feed sections 21 are formed flat and have feed grooves 22 that are opposite to and lowered into the plane of the feed sections 21. A gap 23 exists between the feed groove 22 and the feed rollers 16 and 17, through which the fiber slivers 12 and 13 are transported to the rotating feed rollers 16 and 17.

[0029] The guide housing 24 is arranged in the feeding section 21 directly upstream of the feeding rollers 16, 17, and surrounds each of the two fiber slivers 12, 13 supplied to one of the roller sections 18, 19 on three sides, such that, together with the flat surface of the feeding section 21, it forms a closed guide channel 25, 26 for each of the two fiber slivers 12, 13 as a fourth side. The first guide channel 25 is longer than the second guide channel 26, such that the first fiber sliver 12 supplied from the spinning edge 6 below the guide element 20 cannot contact the second fiber sliver 13 supplied from the coil 27 through the upper side of the guide element 20, thereby achieving completely independent supply of the fiber slivers 12, 13.

[0030] Finally, the integrally formed guide element 20 has an opening roller section 28 that follows the feed trough 22 and extends partially along the surface of the opening roller 14 at a constant distance in the direction of rotation of the opening roller 14. The gap formed between the opening roller section 28 and the surface of the opening roller 14 ensures that the fiber slivers 12, 13 fed from the feed rollers 16, 17 are reliably separated into individual fibers at the surface of the opening roller 14.

[0031] List of reference numerals

[0032] 1. Rotor spinning machine

[0033] 2 workstations

[0034] 3. Free-end rotor spinning equipment

[0035] 4. Winding equipment

[0036] 5 Service Units

[0037] 6 Spinning tank

[0038] 7. Cross-wound winding tube

[0039] 8. Central Control Unit

[0040] 9. Control equipment

[0041] 10 operating units

[0042] 11 Supply Units

[0043] 12 Fiber Strips

[0044] 13 Fiber strips

[0045] 14 Opening Roller

[0046] 15. Rotation axis

[0047] 16 Feeding rollers

[0048] 17 Feeding rollers

[0049] 18 First Roller Section

[0050] 19 Second Roller Section

[0051] 20 Guide elements

[0052] 21 Feeding Section

[0053] 22 Feeding trough

[0054] 23 gap

[0055] 24 Guide housing

[0056] 25 Guide Channels

[0057] 26 Guideway

[0058] 27 coils

[0059] 28 Opening Roller Section

Claims

1. A method for operating a rotor spinning machine (1), the rotor spinning machine having a control device (9), a free-end rotor spinning device (3), and a supply unit (11), the supply unit feeding at least two fiber slivers (12, 13) into the free-end rotor spinning device (3) and having - Opening roller (14), said opening roller is used to open fiber slivers (12, 13), and - A feeding device for the first fiber sliver (12) and the second fiber sliver (13), the feeding device having a first feeding roller and a second feeding roller (16, 17), the first feeding roller and the second feeding roller being operable independently of each other using the control device (9), and guide elements (20) with feeding sections (21) arranged in the feeding direction of the feeding rollers (16, 17), wherein, The feeding section (21) includes a feeding trough (22) opposite to the feeding rollers (16, 17). Its features are, The control device (9) - Determine a separate drafting speed for a feed roller (16, 17), said separate drafting speed being required by producing a yarn with predetermined yarn characteristics from a single fiber sliver (12, 13) fed using said feed roller (16, 17), wherein said predetermined yarn characteristics include the twist, draft, and yarn count of the yarn to be produced, and - The first drafting speed of the first feed roller (16) and the second drafting speed of the second feed roller (17) are coordinated with each other in such a way that the sum of the first drafting speed and the second drafting speed corresponds to the individual drafting speed, and In addition to the individual drafting speed, other spinning parameters for yarn production, including rotor rotation speed and yarn extraction speed, are also determined.

2. The method according to claim 1, characterized in that, The control device (9) detects the number of fiber strips (12, 13) to be fed.

3. The method according to claim 1 or 2, characterized in that, The control device (9) calculates the individual drafting speed based on the predetermined yarn characteristics, or retrieves the individual drafting speed from a database.

4. A rotor spinning machine (1) comprising a control device (9), a free-end rotor spinning device (3), and a supply unit (11) wherein the supply unit feeds at least two fiber slivers (12, 13) into the free-end rotor spinning device (3) and has - Opening roller (14), said opening roller is used to open fiber slivers (12, 13), and - A feeding device for the first fiber sliver (12) and the second fiber sliver (13), the feeding device having a first feeding roller and a second feeding roller (16, 17), the first feeding roller and the second feeding roller being operable independently of each other using the control device (9), and guide elements (20) with feeding sections (21) arranged in the feeding direction of the feeding rollers (16, 17), wherein, The feeding section (21) includes a feeding trough (22) opposite to the feeding rollers (16, 17). Its features are, The control device (9) is designed to be - Determine a separate drafting speed for a feed roller (16, 17), said separate drafting speed being required by producing a yarn with predetermined yarn characteristics from a single fiber sliver (12, 13) fed using said feed roller (16, 17), wherein said predetermined yarn characteristics include the twist, draft, and yarn count of the yarn to be produced, and - 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 drafting speed and the second drafting speed corresponds to the individual drafting speed; and In addition to the individual drafting speed, other spinning parameters for yarn production, including rotor rotation speed and yarn extraction speed, are also determined.

5. The rotor spinning machine (1) according to claim 4, characterized in that, The control device (9) is connected to the operation unit (10) for data input.

6. The rotor spinning machine (1) according to claim 4 or 5, characterized in that, The control device (9) is connected to the computing unit and / or database.

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