CN114746591A

CN114746591A - Spinning station and rotor spinning machine comprising such a spinning station

Info

Publication number: CN114746591A
Application number: CN202080082092.6A
Authority: CN
Inventors: W·拉德马赫; 汉斯-彼得·莫尔; P·威尔特; 于尔根·胡尔森
Original assignee: Zhuolang Intelligent Technology Co ltd
Current assignee: Zhuolang Intelligent Technology Co ltd
Priority date: 2019-11-29
Filing date: 2020-11-27
Publication date: 2022-07-12
Anticipated expiration: 2040-11-27
Also published as: EP3828325A1; WO2021105382A1; US20220403562A1; JP2023504099A; CN114746591B

Abstract

The invention relates to a method for determining a yarn strength of a yarn produced at a spinning station of a rotor spinning machine, said yarn strength being lower than a target value, in addition to a spinning station for a rotor spinning machine and a rotor spinning machine for producing a yarn from a supplied fiber sliver. In order to provide a spinning station and a rotor spinning machine and a method for the same, which allow reliable detection of a yarn from a rotor spinning device having too low a yarn strength, it is provided that a yarn handling unit, which acts mechanically on the yarn, is provided in the region between the rotor spinning device and the winding device, and applies an adjustable yarn tension influencing force, in particular an adjustable braking force, pressure and/or clamping force, to the yarn in order to variably increase the yarn tension. In the method, a yarn tension influencing force which can be adjusted is applied to the yarn by a yarn handling unit which is arranged in the region between the open-end spinning device and the winding device and acts mechanically on the yarn, and the yarn breakage and/or the yarn breakage rate is detected and compared with a predetermined set rate, and the deviation of the yarn breakage and/or the yarn breakage rate exceeding a predetermined limit value is displayed and/or evaluated.

Description

Spinning station and rotor spinning machine comprising such a spinning station

The invention relates to a spinning station and a rotor spinning machine with at least one spinning station for producing a yarn from a supplied fiber sliver, comprising a rotor spinning device for forming a yarn from a fiber sliver supplied by a drafting device and a winding device for accommodating the yarn on a winding bobbin.

The invention also relates to a method for determining a yarn strength of a yarn produced at a spinning station of a rotor spinning machine, said strength being below a target value.

Various embodiments of spinning stations and rotor spinning machines having a plurality of spinning stations arranged next to one another are known from the prior art. Open-end spinning machines are the most common machines for producing yarns from fibrous materials, in addition to rotor spinning machines and ring spinning machines. In open-end spinning, a fiber sliver is generally drawn by a drawing device according to the yarn count to be obtained and then fed to an open-end spinning device. In an open-end spinning device, the outer fibers of a fiber sliver are wound around the inner core fibers of the fiber sliver by means of a swirling air flow generated by one or more spinning air nozzles and thus form a wound fiber which is decisive for the desired yarn count of the yarn. The yarn thus formed is finally drawn off through the draw-off channel of the open-end spinning device and wound onto a bobbin, for example.

Depending on the process, it is possible from time to time for blockages or soiling to occur during the spinning process or for fluctuations in the air pressure/spinning pressure of the air spinning device, for example of the air spinning nozzle or of the area immediately in front of it, to occur. The clogging or soiling here originates mainly from the fibers of the fiber sliver, which collect before the air spinning nozzle and lead to the wrapping fibers no longer winding the core fibers in the intended manner. Since the wrapping fibers are of interest for the yarn strength, this results in the yarn coming out of the open-end spinning device no longer having the required yarn strength. Faulty yarns have so-called weak spots, which are not reliably identifiable by known methods, such as optical methods.

In view of this, the invention is based on the object of providing a spinning station and a rotor spinning machine which allow a reliable identification of a yarn from a rotor spinning device having an excessively low yarn strength. The invention is based on the object of providing a method for determining a yarn strength of a yarn produced at a spinning station of a rotor spinning machine which is below a predetermined target value.

The invention achieves this object by means of a spinning station having the features of claim 1, a rotor spinning machine having the features of claim 7 and a method having the features of claim 11. Advantageous developments of the spinning station and the rotor spinning machine are specified in the dependent claims.

The spinning station according to the invention is characterized in that a yarn handling unit which acts mechanically on the yarn is arranged in the region between the open-end spinning device and the winding device and which applies an adjustable yarn tension influencing force to the yarn in order to variably increase the yarn tension.

The yarn handling unit of the spinning station according to the invention allows the yarn tension of the yarn from the open-end spinning device to be limited to a defined value in a defined manner in the region between the open-end spinning device and the winding device. The adjustable yarn tension is aimed at the desired yarn strength of the spun yarn and may, for example, be selected such that a fluctuation in the yarn strength within acceptable tolerances does not affect the spinning process. However, if the yarn strength is below the maximum permissible limit value, the higher yarn tension produced by the yarn handling unit causes yarn breaks, which can already be estimated as an indication of a fault during the spinning process which is the cause of the reduced yarn strength.

The thread control unit acts mechanically on the thread and is designed such that the thread tension can be adjusted in a versatile manner depending on the thread to be spun by means of an adjustable thread tension influencing force acting on the thread. The thread tension influencing force can be realized here in a preferred manner by means of an adjustable braking force, pressure and/or clamping force.

By increasing the yarn tension by the yarn handling unit, it is thus possible to reliably identify a yarn having a defect by an intentional yarn break, so that measures can be taken immediately at the spinning station to eliminate the cause of the defect. The production and subsequent winding of a yarn with too low a yarn strength can thus be reliably prevented at the spinning station of the invention, since faults can be identified and eliminated as early as possible.

The adjustment of the yarn tension influencing force, which increases the yarn tension, by means of the yarn handling unit acting mechanically on the yarn, can in principle be carried out in any way. However, according to an advantageous development of the invention, it is provided that the thread handling unit has at least one adjustable clamping device facing the thread. The clamping force acting on the yarn and thus the yarn tension can be adjusted to a predetermined value in a simple and reliable manner by means of the clamping mechanism acting on the yarn, preferably transversely to the direction of movement of the yarn. The clamping device can be designed such that it bears against the thread in a point-like manner or, as viewed in the thread running direction, by means of a section and thus produces a sufficiently high thread tension influencing or clamping force.

In particular, the planar arrangement of the at least one clamping means on a section of the thread allows the clamping force to be adjusted due to the length of contact with the clamping means in such a way that there is no risk of the thread being damaged by the engagement with the clamping means.

In addition to the advantageous provision for the use of at least one clamping device for increasing the yarn tension, it is also possible to increase the yarn tension alternatively or additionally by changing the yarn direction, wherein the yarn handling unit has a suitable deflection device for this purpose, whereby the yarn direction can be adjusted in a versatile manner. The yarn tension can thus be determined very reliably in dependence on the yarn deflection caused by the deflection mechanism, which exerts a pressure on the yarn in dependence on its position. The design of the deflecting device is in this case in principle freely selectable, wherein according to a particularly advantageous design of the invention it is provided that the thread handling unit has adjustable loops for changing the thread direction in a multiplicity of ways. According to this preferred embodiment of the invention, the thread passes through the adjustable loops of the thread handling unit, wherein by positioning the loops in contact with the thread, the thread direction is changed and pressure is applied to the thread. The pressure then prevails at the loop position opposite the position at which the thread runs independently of the thread control unit. The adjustable loop thus ensures very reliably that the yarn handling unit engages the yarn. At the same time, damage to the thread engaging the loops can be reliably avoided by the design of the loops, for example the surface conditions.

The design of the at least one clamping mechanism, which is advantageously provided, can in principle be freely selected, which in principle opens up the possibility of also providing a design for a care thread. According to a very advantageous embodiment of the invention, it is provided that the clamping means are formed by a disk tensioner and/or a rake tensioner. The use of such tensioners has the advantage that they allow very precise adjustment of the clamping and thus the clamping force. For example, it is possible to use a disk tensioner which acts on the yarn by means of an adjustable yarn tension, wherein the clamping force is reliably applied to the yarn by the contact length of the disk with the yarn and at the same time damage to the yarn is reliably avoided because of this contact length.

Furthermore, the thread control unit can have a thread braking mechanism according to a preferred embodiment, which comprises a thread contact portion for contacting the moving thread, which is designed to brake the moving thread as specified by means of a braking force acting on the thread. For example, the thread brake can be formed by the deflection mechanism. Generally, the mechanism contacting the yarn has a surface which remains as small as possible with respect to the effect of the moving yarn. In order to divert the thread direction in a purely versatile manner, the diverting mechanism can according to a preferred embodiment be designed with such a surface coating contacting the thread, so that the thread is essentially subjected only to the pressure caused by the diversion in order to influence the thread tension. According to another preferred embodiment, the steering mechanism may be provided with a friction-increasing surface coating contacting the yarn, which applies a braking force to the yarn in addition to the pressure. According to an alternative preferred embodiment, the yarn braking mechanism can be designed with a component which is or can be assigned to the spinning station and which has a surface section which is provided for contacting the moving yarn without deflecting it.

The adjustment of the adjusted yarn tension influencing force by means of the yarn handling unit, for example a preferably predetermined deflection mechanism and/or a preferably predetermined clamping mechanism acting on the yarn and/or a preferably yarn braking mechanism acting on the yarn, can be carried out manually, wherein for this purpose the machine operator for example performs a corresponding adjustment of the yarn handling unit. However, according to a particularly preferred embodiment of the invention, it is provided that the thread tension influencing force is adjustable electrically. The electrical adjustment of the thread tension influencing force on the one hand increases the comfort of the adjustment of the thread handling unit and on the other hand allows a very accurate adjustment of the thread tension influencing force. For the electrically controlled adjustment of the thread tension influencing force, for example, a suitable actuator motor can be used, by means of which the position of the predetermined deflection or clamping mechanism or thread brake mechanism relative to the thread can advantageously be adjusted precisely.

The adjustment of the yarn tension can be carried out, for example, by aligning suitable scales on a steering mechanism and/or a clamping mechanism and/or a yarn brake mechanism which are advantageously provided.

According to an advantageous embodiment of the invention, a sensor is provided for measuring the yarn tension of the yarn section that can be influenced or influenced by the yarn handling unit.

The use of such a sensor, which also allows a visual display of the yarn tension adjusted by the yarn handling unit by means of a suitable display unit wirelessly or wired connectable or connected to the sensor, allows a particularly precise adjustment of the yarn tension. Furthermore, the use of such a sensor in combination with the electrically adjustable, advantageous setting of the thread tension influencing force offers the possibility of automatically adjusting and controlling the thread tension by means of a central unit by means of a suitable control and adjustment unit, without manual adjustment by the machine operator being necessary for this purpose. The use of such a sensor thus allows to maintain a constant yarn tension for a long time.

The yarn handling unit can in principle be arranged at any position between the open-end spinning device and the winding device at the spinning station. However, according to a very advantageous embodiment of the invention, it is provided that the yarn handling unit is arranged in the region between the open-end spinning device and a yarn withdrawal unit connected to the open-end spinning device. The yarn withdrawal unit is, for example, a driven pair of withdrawal rollers, by means of which the yarn is withdrawn from the open-end spinning device. Since the thread tension is generally constant in this region without the action of the thread handling unit, this region is particularly advantageously suitable for causing a change in the thread tension by the thread handling unit. Furthermore, the area of the spinning station usually has a sufficiently large installation space for the simple arrangement of the thread handling unit.

The invention also relates to a rotor spinning machine for producing a yarn from a supplied fiber sliver, comprising at least one spinning station according to the invention or the improvement described above. The rotor spinning machines generally have a plurality of spinning stations arranged next to one another, at which a yarn is spun simultaneously from a supplied fiber sliver. The rotor spinning machine according to the invention has the advantage that a thread with an excessively low thread strength value is recognized as early as possible and therefore measures for eliminating possible faults that lead to a reduction in the thread strength can be initiated immediately.

According to a particularly advantageous embodiment of the invention, the rotor spinning machine has an evaluation unit for detecting yarn breakage and/or a yarn breakage rate at the spinning stations, which also performs a comparison of the yarn breakage rate with a predefinable setpoint ratio. The rotor spinning machine designed according to the development of the invention automatically monitors the spinning stations by means of an evaluation unit and identifies yarn breaks and/or measures the rate of yarn breaks at the spinning stations. Thus, depending on the selectable indicator, there is the possibility of displaying it to the operator, who may then conduct a cause investigation and perhaps perform measures suitable for troubleshooting. For example, the evaluation unit can already display the yarn break and this leads to an inspection by the operator. Alternatively, the display can be carried out in dependence on the yarn breakage rate measured by an evaluation unit, for example, an information provision device of the rotor spinning machine, i.e. when the yarn breakage rate differs from an expected value in a predetermined manner.

According to an advantageous embodiment of the invention, the rotor spinning machine also has a computing unit for detecting the yarn tension by means of a yarn tension sensor provided at the spinning station and for adjusting the yarn tension influencing force of the yarn handling unit. The use of an adjusting unit allows the yarn-specific yarn tension to be adjusted in an automated manner at some spinning stations, which leads to yarn breaks in the event of too low a yarn strength of the spun yarn. The use of the regulating unit allows automation and particularly comfortable regulation and monitoring of the spinning process of several spinning stations.

The invention also provides a method for detecting yarn strengths below a target value at a spinning station of a rotor spinning machine, wherein according to the method of the invention, an adjustable yarn tension influencing force is applied to the yarn by means of a yarn handling unit, which is arranged in the region between the rotor spinning device and the winding device and which acts mechanically on the yarn, a yarn break and/or a yarn breakage rate is detected and compared with a predetermined target rate, and a yarn break and/or a deviation of the yarn breakage rate beyond a predetermined limit value is displayed and/or evaluated, in particular, for initiating a measure.

The method according to the invention makes use of the fact that faults in the spinning process of the open-end spinning device lead to a reduction in the yarn strength of the spun yarn. By means of the yarn handling unit, the yarn tension can be limited to a value which corresponds to the desired yarn strength. If the yarn strength is lower than the expected yarn strength due to an error in the spinning process, a yarn break occurs due to an increased yarn tension caused by the yarn handling unit, which can be estimated as an indication of a malfunction in the spinning process, for example because the open-end spinning device is contaminated.

According to the method of the invention, yarn breaks and/or rate of yarn breaks at some azimuthal locations are detected. Depending on the process parameters to be set, a yarn break can already be estimated as an indication of a fault in the spinning process, so that the operator is shown a yarn break, which then takes appropriate action. In addition or alternatively, a possible malfunction of the spinning process can also be signaled to the operator only when the expected yarn breakage rate is exceeded, and the operator then performs a check or possible elimination of the malfunction in a similar manner.

The spinning station or rotor spinning machine may in particular be a spinning station or rotor spinning machine according to one of the preferred embodiments described above.

One embodiment of the invention is explained below with reference to the figures, which show:

FIG. 1 shows a simplified view of a rotor spinning machine having a plurality of spinning stations according to a preferred embodiment;

FIG. 2 shows a spinning station of the rotor spinning machine of FIG. 1 in normal spinning operation; and

fig. 3 shows a yarn handling unit with a clamping mechanism of the spinning station of fig. 2.

Fig. 1 shows, in a simplified illustration, a rotor spinning machine 1 having a plurality of spinning stations 2 arranged next to one another according to a preferred embodiment. Each spinning position 2 comprises a fiber sliver source 3, which can be designed, for example, as a spinning can, a drafting device 4, an open-end spinning device 5, a pair of draw-off

rollers

6a,6b, a yarn clearer 7, a yarn distribution device 8, a yarn handling unit 17 and a cross-wound bobbin 9 of a winding device. The service trolley 10 is mounted movably on

rails

11, 12 extending along the rotor spinning machine 1. On the longitudinal side ends of the rotor spinning machine 1, machine end housings 13 are provided for the arrangement of the central devices required for the operation of the rotor spinning machine 1.

Fig. 2 shows a spinning station 2 according to a preferred embodiment in normal spinning operation. The fiber sliver 14 provided by the fiber sliver source 3 passes through the drawing frame 4, where it is drawn. The drafted fiber sliver 14 is then supplied to the air-jet spinning device 5 by the pair of

output rollers

16a,16b of the draft mechanism 4. In the open-end spinning device 5, the outer fibers of the fiber sliver 14 are wound onto the inner core fibers of the fiber sliver 14 due to the air flow generated in the open-end spinning device 5, thereby forming the wound fibers that are decisive for the desired strength of the yarn 15. The spun yarn 15 is drawn off from the open-end spinning device 5 by the draw-off

roller pair

6a,6b and wound on a cross-wound bobbin 9 of the winding device after passing through the clearer 7 and the yarn distribution device 8.

In the region between the open-end spinning device 5 and the pair of draw-off

rollers

6a,6b, the yarn 15 passes through a yarn handling unit 17, whereby a yarn tension influencing force is mechanically exerted on the yarn 15, which results in an increase of the yarn tension. The yarn tension that can be set by the yarn tension influencing force is intended for the desired yarn strength and is dimensioned such that a yarn break occurs due to an increased yarn tension when the yarn strength is below the desired value.

An embodiment of a yarn handling unit 17 for applying a yarn tension influencing force to the yarn 15 is shown in fig. 3. The thread handling unit 17 has two clamping

disks

23a,23b which are adjustable at a distance from one another and between which the thread 15 is guided. The clamping force acting on the thread 15 thereby dominates the spring stress exerted by the threaded compression spring 21, which in turn results from the distance between the clamping disk 23a and a stop 22 adjustable along the shaft 20, against which the opposite ends of the helical compression spring 21 abut. The adjustment of the stop 22 and thus of the distance between the clamping disk 23a and the stop 22 is performed here by an actuating motor 18 provided on the stand 19 for rotating the shaft 20, which actuating motor is connected to a control and regulating unit, not shown here, of the rotor spinning machine.

According to an embodiment not shown here, the thread handling unit 17 has a loop through which the thread 15 passes, the loop being adjustable transversely to the thread running direction. The turning of the thread direction is carried out by displacing the loops, wherein the thread tension influencing force acting on the thread in the form of a pressure and in particular an additional braking force, and thus the thread tension, can be adjusted depending on the position of the loops. The additional braking force which is preferably provided can be achieved according to a preferred embodiment by a corresponding surface coating which contacts or deflects the loop surface portions of the yarn.

According to an embodiment, also not shown, for generating such a braking force, a yarn braking mechanism is provided, which comprises a yarn contact portion for contacting the moving yarn, which is designed to brake the moving yarn as specified by means of the braking force acting on the yarn.

List of reference numerals

1 air spinning machine

2 spinning station

3 fibre sliver source

4 drafting mechanism

5 air spinning device

6a,6b draw-off roller pair

7 yarn cleaner

8 cloth yarn device

9 Cross-wound bobbin

10 service trolley

11 track

12 track

13 machine end housing

14 fiber strip

15 yarn

16a,16b delivery roller pair

17 yarn handling unit

18-execution motor

19 support

20 shaft

21 helical compression spring

22 stop

23a,23b clamp the disc.

Claims

1. A spinning station of a rotor spinning machine for producing a yarn from a supplied fibre sliver has

-an open-end spinning device (5), said open-end spinning device (5) being adapted to form a yarn (15) from at least one fibre sliver (14) supplied by a drafting means (4), and

-a winding device for receiving the yarn on a winding bobbin (9),

characterized in that a yarn handling unit (17) acting mechanically on the yarn (15) is arranged in the region between the open-end spinning device (5) and the winding device, the yarn handling unit (17) applying an adjustable yarn tension influencing force, in particular an adjustable braking force, pressure and/or clamping force, to the yarn (15) in order to variably increase the yarn tension.

2. A spinning station according to claim 1, characterised in that the yarn handling unit (17) has adjustable clamping means (23a,23b) in the direction towards the yarn (15).

3. Spinning station according to claim 2, characterized in that the clamping means (23a,23b) are constituted by a disc tensioner and/or a rake tensioner for adjustably tensioning the yarn.

4. Spinning station according to one or more of the preceding claims, characterized in that the yarn handling unit (17) has adjustable deflection means, in particular adjustable loops for variably changing the yarn direction.

5. A spinning station according to one or more of the preceding claims, characterised in that the force that can be adjusted is electrically adjustable.

6. A spinning station according to one or more of the preceding claims, characterised in that sensors are provided for the yarn tension measurement of the yarn sections influenced by the yarn handling unit (17) or that can be influenced by the yarn handling unit (17).

7. A spinning station according to one or more of the preceding claims, characterised in that the yarn handling unit (17) is arranged in the area between the open-end spinning device (5) and a yarn extraction unit (6a,6 b).

8. Rotor spinning machine for producing a yarn from a supplied fibre sliver, characterized in that at least one spinning station (2) according to one or more of claims 1 to 7 is provided.

9. Rotor spinning machine according to claim 8, characterised in that an associated evaluation unit is provided for detecting a yarn break and/or a yarn break rate at the spinning stations (2) and for comparing the yarn break rate with a predefinable setpoint rate.

10. Rotor spinning machine according to claim 8 or 9, characterised in that an associated computing unit is provided for detecting the yarn tension and for adjusting the yarn tension influencing force of the yarn handling unit (17) by means of a yarn tension sensor provided at the spinning station (2).

11. A method for determining a yarn strength of a yarn produced at a spinning station of a rotor spinning machine, which is lower than a theoretical value,

-exerting an adjustable yarn tension influencing force on the yarn (15) by means of a yarn handling unit (17) arranged in the area between the open-end spinning device (5) and the winding device, acting mechanically on the yarn, and

-detecting and comparing the yarn breakage and/or the yarn breakage rate with a predetermined theoretical ratio, and displaying and/or evaluating the yarn breakage and/or deviation of the yarn breakage rate beyond a predetermined limit value.