Spinning station for a rotor spinning machine, rotor spinning machine and spinning method

Abstract

The invention relates to a spinning station of a rotor spinning machine with an improved yarn take-up device, a rotor spinning machine and a method for taking up a yarn. The spinning station comprises a sliver supply mechanism, an opening mechanism, a spinning rotor producing a yarn from the sliver, a yarn take-up device comprising a take-up roller and a pressure roller cooperating with the yarn from the spinning rotor, a winding mechanism comprising a winding roller and a bobbin such that the yarn is wound on the bobbin, wherein the yarn take-up device takes up the yarn and comprises a tube capable of at least partially containing and accumulating the yarn, a control unit operatively connected with the yarn take-up mechanism, the sliver supply mechanism and the winding mechanism, the control unit being programmed such that, during spinning, the yarn take-up device at least partially aspirates the portion of the yarn within the tube to control the slack of the yarn during spinning. The invention solves the problem of non-ideal yarn tension during spinning and enables to reduce the slack.

Description

Technical Field

[0001] The present invention relates to a spinning station of a rotor spinning machine with an improved yarn take-up device, a rotor spinning machine, and a method for take-up yarn. Background Technology

[0002] As is well known, in order to obtain the same yarn quality on a rotor spinning machine, the start of yarn take-up needs to be highly synchronized with the start of yarn winding, and thus eliminate the possibility of different yarn take-up times in the rotor. Current prior art solutions do not allow for such synchronization, therefore a small interval needs to be created between the start of yarn take-up and the start of yarn winding.

[0003] However, in order to separate the start of yarn take-up from the start of yarn winding, additional devices are needed to take up the yarn at the same time as it is being formed.

[0004] At the same time, in order to achieve uniform yarn spinning time in the rotor, it is necessary to minimize transients during the yarn take-up and yarn splicing stages.

[0005] The known solutions cannot solve the above-mentioned technical problems. Summary of the Invention

[0006] Therefore, it is necessary to address the shortcomings and limitations mentioned in the existing technology.

[0007] Such needs are met by the spinning station of a rotor spinning machine with an improved yarn take-up device according to the invention, the rotor spinning machine according to the invention, and the related spinning method according to the invention.

[0008] According to one embodiment of the invention, the spinning station includes: - a yarn supply mechanism, an shedding mechanism, and a spinning rotor for producing yarn from the yarn; - a yarn take-up device, the yarn take-up device including a take-up roller and a pressure roller cooperating with the yarn from the spinning rotor; - a winding mechanism, the winding mechanism including a winding roller and a bobbin such that the yarn is wound onto the bobbin, wherein the yarn take-up device acquires the yarn and includes a tube capable of at least partially containing and accumulating the yarn; - a control unit operatively connected to the yarn take-up device, the yarn supply mechanism, and the winding mechanism, the control unit being programmed such that: during spinning, the yarn take-up device at least partially draws a portion of the yarn within the tube to control the slack of the yarn during spinning, and then gradually releases the yarn back for winding, wherein the yarn take-up device includes an air injector to generate a negative pressure within the tube by means of compressed air, thereby drawing the yarn.

[0009] According to another embodiment of the present invention, the rotor spinning machine includes the spinning station as described in the previous embodiment.

[0010] According to another embodiment of the invention, the spinning method includes the following steps: - providing a spinning station as described in a previous embodiment; - during spinning, at least partially aspirating a portion of the yarn within the tube of the yarn take-up device to control the slack of the yarn during spinning; and then gradually releasing the yarn back for winding, wherein the yarn take-up device includes an air injector to generate a negative pressure within the tube by means of the compressed air, thereby at least partially aspirating the yarn. Attached Figure Description

[0011] Other features and advantages of the invention will become more readily apparent from the following description of preferred and non-limiting embodiments thereof, as illustrated in the accompanying drawings:

[0012] Figure 1 A side view of a spinning station including a yarn take-up device according to a feasible embodiment of the present invention is shown;

[0013] Figure 2 It shows Figure 1 A detailed front view of II;

[0014] Figure 3 A side view of a spinning station including a yarn take-up device is shown according to another feasible embodiment of the present invention;

[0015] Figure 4 It shows Figure 3 A front view of the details of IV.

[0016] Elements or parts of elements common to the embodiments described below will be indicated using the same reference numerals. Detailed Implementation

[0017] Referring to the aforementioned attached diagram, the spinning station is generally represented by 30.

[0018] Spinning station 30 typically belongs to rotor spinning machines (not shown).

[0019] In any case, for the purposes of this invention, the spinning station 30 and the rotor spinning machine may have any type, shape and size.

[0020] The spinning station 30 includes a yarn supply mechanism 21, an shedding mechanism 22, and a spinning rotor 19 for producing yarn 5 from the yarn.

[0021] In addition, the spinning station 30 includes a yarn take-up device 6, which includes a take-up roller 11 and a pressure roller 12 that cooperate with the yarn 5 from the spinning rotor 19.

[0022] The spinning station 30 also includes a winding mechanism, which includes a winding roller 13 and a bobbin 15 for winding the yarn onto the bobbin 15.

[0023] The yarn take-up device 6 acquires the yarn 5 and includes a tube 4 (or suction nozzle 4) capable of at least partially containing and accumulating the yarn 5.

[0024] The spinning station 30 includes a control unit 25, which is operatively connected to the yarn take-up device 6, the yarn supply mechanism 21 and the winding mechanism 14.

[0025] Advantageously, the control unit 25 is programmed such that during spinning and / or splicing cycles, the yarn take-up device 6 at least partially draws a portion of the yarn within the tube 4 in order to control the slack of the yarn 5 during spinning, and then gradually releases the yarn back for winding.

[0026] Specifically, the yarn take-up device 6 includes an air syringe 1 to generate a negative pressure 9 within the tube 4 by means of compressed air 8, thereby drawing in the yarn 5.

[0027] According to a feasible embodiment, as the yarn 5 travels, the yarn take-up device 6 at least partially draws in a portion of the yarn 5 within the tube 4.

[0028] According to a feasible embodiment, the spinning station 30 includes a compressed air system operatively connected to both the yarn take-up device 6 and the pressure device 16 (typically an arm), wherein the pressure device acts on the winding roller 13 and / or the bobbin 15 to change the contact pressure between the winding roller and the bobbin.

[0029] Preferably, the control unit 25 uses the compressed air system to change the pressure contact between the winding roller 13 and the bobbin 15 based on the slack of the yarn 5 and the length of the yarn 5 obtained by the yarn take-up device 6.

[0030] According to a feasible embodiment, the compressed air system has a nozzle 3 with an adjustable diameter for the syringe 1.

[0031] According to a feasible embodiment, the nozzle 3 of the syringe 1 is replaceable so that its shape can be changed.

[0032] According to a feasible embodiment, the flow of compressed air 8 entering the suction nozzle 3 is discontinuous.

[0033] According to a feasible embodiment, the control unit 25 is programmed such that the switching on and off of the compressed air 8 can be controlled individually, partially, or simultaneously at each location of the machine.

[0034] According to a feasible embodiment, the control unit is programmed such that, before the yarn 5 is wound onto the bobbin 15, i.e. before the bobbin 15 has come into contact with the winding roller 13, the yarn take-up device 6 temporarily takes up the yarn 5 and then gradually releases the yarn for winding.

[0035] The operation of the yarn take-up apparatus according to the present invention will now be described.

[0036] Specifically, compressed air 8 passes through a nozzle 3 with a replaceable cross-section into the diffuser 2, generating a negative pressure 9 in the suction nozzle or tube 4, wherein the suction nozzle or tube is located near the yarn spinning axis and helps the yarn 23 smoothly reach the spinning axis from the yarn base pin 24 when the yarn take-up stops, i.e., when the pressure roller 12 is not in contact with the take-up roller 11. Thus, the yarn end 20 smoothly reaches the spinning rotor 19 for splicing under the condition that the suction of the yarn take-up device 6 is modulated so as not to affect or interfere with the suction of the spinning rotor 19.

[0037] In addition, when winding stops, that is, when the bobbin 15 is no longer in contact with the winding roller 13, the yarn 5 can be wound up for a period of time and then gradually released into the winding section to ensure the uniformity of the splicing and to avoid breakage of the yarn 5 from the bobbin 15 in subsequent processing.

[0038] The replaceable suction nozzle or tube 4 has interchangeable shapes to achieve optimal yarn take-up, depending on the need.

[0039] According to a feasible embodiment, the source of compressed air 8 is connected via valve 28 to control unit 25 of spinning station 30, which controls the source of compressed air and can also be connected to a yarn presence sensor for feasible adjustment of the start time of the device.

[0040] After ensuring yarn take-up and obtaining appropriate yarn tension 7 between take-up roller 11 and winding roller 13, the source of compressed air 8 can be shut off, which can be done by setting the take-up time at a fixed time or by using a yarn presence sensor.

[0041] Furthermore, this device can also advantageously reduce slack in the yarn 5 during winding on the bobbin 15 due to the construction of soft bobbins or other non-standard bobbins. A full flow from a smaller suction nozzle 3 or an intermittent airflow can be used, which will significantly reduce the need for compressed air, allowing for longer operation. The same principle can be used when winding on a tapered bobbin 15 (where periodic slack occurs due to different bobbin diameters).

[0042] The yarn take-up device 6 can also be used to reduce slack during the stopping and restarting of spinning on a rotor spinning machine via controlled stop and start functions (both via standard machine power and in case of power failure). A negative pressure is generated before spinning stops to properly tension the yarn during unwinding on the bobbin. When the compressed air is restored, the yarn can be re-tensioned through this device, and if necessary, excess yarn can be pulled out for a period of time and then gradually released for winding as the yarn end is introduced into the rotor before the pulled-out portion is retracted.

[0043] To reduce the occurrence of slack yarn 60 that may cause spinning interruption during shearing, the device is turned on before shearing begins, and a full or intermittent airflow generates the necessary negative pressure 9 to draw the slack yarn 60 into the suction nozzle or tube 4 of the syringe (jet pump) 1, thereby reducing any slack caused, for example, by greater friction of the yarn on certain parts of the yarn or insufficient vacuum in the exhaust pipe of the doffing device or the auxiliary exhaust pipe of the machine.

[0044] The activation time of the yarn take-up device depends on various variables, including, for example, the yarn count being processed, the winding speed, and the yarn material.

[0045] In addition, the activation time of the yarn take-up device can be automatically calculated and set by the machine's central processing unit, or it can be set manually.

[0046] As can be understood from the above description, the present invention allows for overcoming the disadvantages introduced in the known art.

[0047] In particular, the solution according to the invention includes a yarn take-up device that is opened before take-up begins, which solves the problem of needing to minimize transients during the yarn take-up and yarn splicing stages.

[0048] Furthermore, the device effectively solves the problem of unsatisfactory yarn tension during spinning on soft winding sections, non-standard winding sections, or tapered spools, thereby improving winding quality. Additionally, it can be advantageously used for automatic doffing.

[0049] Furthermore, the device according to the invention can also be advantageously used to reduce yarn slack during winding on a bobbin due to the construction of a soft bobbin or other non-standard bobbin. For example, a full flow from a smaller suction nozzle or an intermittent airflow can be used, which will significantly reduce the need for compressed air, allowing for longer operation. The same principle can be used when winding on a tapered bobbin (where periodic slack occurs due to different bobbin diameters).

[0050] The device can also be used to reduce slack during the stopping and restarting of spinning on a rotor spinning machine via controlled stop and start functions (both via standard machine power and in the event of a power failure). A negative pressure is generated before spinning stops to properly tension the yarn during unwinding on the bobbin. When the compressed air is restored, the yarn can be re-tensioned through this device, and if necessary, excess yarn can be pulled out for a period of time and then gradually released for winding as the yarn end is introduced into the rotor before the pulled-out portion is retracted.

[0051] To reduce the occurrence of slack yarn that may cause spinning interruptions during shearing, this device can be turned on before shearing begins, and the full or intermittent airflow generates the necessary pressure to draw the slack yarn into the suction nozzle of the syringe (jet pump), thereby reducing any slack caused, for example, by greater friction of the yarn on certain parts of the yarn or insufficient vacuum in the exhaust pipe of the doffing device or the auxiliary exhaust pipe of the machine.

[0052] Compared to spinning machines using centralized air intake systems, using a localized air injector to draw yarn by creating negative pressure within the tubes of the yarn take-up device using compressed air is a true improvement. In fact, compared to centralized solutions, localized air injectors offer the possibility of obtaining precise values ​​of negative pressure within the tubes. In this way, yarn length and tension control are more precise compared to solutions using centralized air intake systems. Furthermore, this method does not interfere with the function of centralized systems, and total air consumption is significantly reduced.

[0053] Advantageously, this device can be used as a self-contained part of an automatic or semi-automatic machine.

[0054] The solution according to the invention largely eliminates the problem of slack yarn wound onto bobbins on rotor spinning machines, which can cause problems during additional processing, especially in the following situations:

[0055] - Relaxation that occurs during or immediately after head growth.

[0056] -Slack that occurs during yarn distribution, especially at high pull-out speeds, when yarn is wound onto a spool.

[0057] - Relaxation during doffing due to, for example, increased friction between the yarn and the contact edges, or due to a small negative pressure after temporarily pulling the yarn out of the bobbin.

[0058] - Relaxation in cases with non-standard winding sections, soft winding sections, or tapered spools

[0059] - Laxity due to different technical speeds (feeding or pulling), especially when producing fancy yarns.

[0060] Furthermore, the solution provides a reduction in slack during the stop and start of multiple spinning units and significantly eliminates the defect of different speeds of yarn insertion and subsequent removal from the rotor during the yarn generation process.

[0061] Those skilled in the art can make various changes and variations to the above-described apparatus and methods to meet possible and specific needs, and all of these are included within the scope of the invention as defined by the appended claims.

[0062] Reference number list

[0063] 1. Syringe (jet pump)

[0064] 2. Diffuser

[0065] 3. Suction nozzle

[0066] 4. Tube (suction nozzle)

[0067] 5. Yarn

[0068] 6. Yarn winding device

[0069] 7. Appropriate yarn tension

[0070] 8. Source of compressed air

[0071] 9. The negative pressure generated

[0072] 10. Exit air

[0073] 11. Remove the roller

[0074] 12. Pressure roller

[0075] 13. Winding roller

[0076] 14. Pipe

[0077] 15. Thread spool

[0078] 16. Pressure device (arm)

[0079] 17. Yarn distribution

[0080] 18. Passive compensator

[0081] 19. Spinning rotor

[0082] 20. Yarn ends used for starting the yarn.

[0083] 21. Supply institutions

[0084] 22. Choosing an organization

[0085] 23. Spare Yarn Spinning Section

[0086] 24. Spare retaining pin

[0087] 25. Control Unit

[0088] 28. Valve

[0089] 30. Spinning station

[0090] 60. Relaxed yarn

Claims

1. A spinning station (30) of a rotor spinning machine, the spinning station comprising: - Yarn supply mechanism (21), shedding mechanism (22), spinning rotor (19) for producing yarn from yarn. - Yarn take-up device (6), which includes a take-up roller (11) and a pressure roller (12) that cooperate with the yarn from the spinning rotor (19). - A winding mechanism (14), which includes a winding roller (13) and a bobbin (15) such that the yarn is wound onto the bobbin (15). The yarn take-up device (6) acquires the yarn (5) and includes a tube (4) capable of at least partially accommodating and accumulating the yarn (5). - A control unit (25), operatively connected to the yarn take-up device (6), the yarn supply mechanism (21), and the winding mechanism (14), wherein the control unit (25) is programmed such that: During spinning, the yarn take-up device (6) at least partially draws a portion of the yarn (5) within the tube (4) to control the slack of the yarn (5) during spinning, and then gradually releases the yarn back for winding, wherein the yarn take-up device (6) includes an air injector (1) to generate a negative pressure (9) within the tube by means of compressed air (8), thereby drawing the yarn (5). The spinning station includes a compressed air system, which is operatively connected to the yarn take-up device (6) and a pressure device. The pressure device acts on the winding roller (13) and / or the bobbin (15) to change the contact pressure between the winding roller and the bobbin. Furthermore, the control unit (25) uses the compressed air system to change the pressure contact between the winding roller (13) and the bobbin (15) based on the slack of the yarn (5) and the length of the yarn obtained by the yarn take-up device (6).

2. The spinning station (30) according to claim 1, wherein, The control unit (25) is programmed such that when the yarn (5) is traveling, the yarn take-up device (6) at least partially draws the portion of the yarn (5) inside the tube (4).

3. The spinning station (30) according to claim 1 or 2, wherein, The source of the compressed air (8) is connected via a valve (28) to the control unit (25) of the spinning station (30), which controls the source of the compressed air and is also connected to a yarn presence sensor.

4. The spinning station (30) according to claim 1 or 2, wherein, The syringe (1) has a nozzle (3) with an adjustable diameter.

5. The spinning station (30) according to claim 4, wherein, The nozzle (3) of the syringe (1) is replaceable so that its shape can be changed.

6. The spinning station (30) according to claim 4, wherein, The flow of compressed air (8) entering the nozzle (3) is discontinuous.

7. The spinning station (30) according to claim 1 or 2, wherein, The control unit (25) is programmed such that the switching on and off of the compressed air (8) can be controlled individually, partially or simultaneously at each location of the machine.

8. The spinning station (30) according to claim 1 or 2, wherein, The control unit (25) is programmed such that the yarn take-up device (6) temporarily takes up the yarn (5) before the yarn (5) is wound onto the bobbin (15), i.e. before the bobbin (15) has come into contact with the winding roller (13), and then gradually releases the yarn for winding.

9. A rotor spinning machine, comprising a spinning station (30) according to any one of claims 1 to 8.

10. A spinning method, the spinning method comprising the following steps: - Provide a spinning station (30) according to any one of claims 4 to 6. - During spinning, at least a portion of the yarn (5) within the tube (4) of the yarn take-up device (6) is drawn in to control the slack of the yarn (5) during spinning, and then the yarn is gradually released back for winding. The yarn take-up device (6) includes an air syringe (1) to generate a negative pressure (9) in the tube by means of the compressed air (8), thereby at least partially drawing up the yarn (5).

11. The spinning method according to claim 10, wherein, The compressed air system is operatively connected to the yarn take-up device (6) and the pressure device, wherein the pressure device acts on the winding roller (13) and / or the bobbin (15) to change the contact pressure between the winding roller and the bobbin, the method comprising the following steps: by means of the compressed air system, simultaneously controlling both the negative pressure of the yarn take-up device (6) and the contact pressure between the winding roller (13) and the bobbin (15) based on the slack of the yarn (5) and the length of the yarn (5) obtained by the yarn take-up device (6).

12. The spinning method according to claim 10 or 11, further comprising the following step: - The compressed air (8) entering the diffuser (2) through the nozzle (3) with a replaceable cross section generates a negative pressure (9) in the tube (4) located near the spinning axis of the yarn and when the yarn take-up stops, i.e. the pressure roller (12) is not in contact with the take-up roller (11), the yarn (5) is smoothly brought from the yarn base pin (24) to the spinning axis, and the yarn end (20) is smoothly brought to the spinning rotor (19) for splicing.

13. The spinning method according to claim 10 or 11 further comprises the following step: - When winding stops, that is, when the bobbin (15) is not in contact with the winding roller (13), the yarn (5) is wound up for a period of time and gradually released into the winding section to ensure the uniformity of the splicing and to prevent the yarn (5) from the bobbin (15) from breaking in subsequent processing.

14. The spinning method according to claim 10 or 11, further comprising the following step: - By using the full flow of a smaller suction nozzle (3) or by using intermittent airflow, the slack of the yarn during winding on the bobbin (15) due to the construction of a soft bobbin, tapered bobbin or other non-standard bobbin will be reduced, which will significantly reduce the need for compressed air for longer use.

15. The spinning method according to claim 10 or 11, further comprising the following step: - Reduce the slack of the yarn (5) during the stopping and restarting of spinning on the rotor spinning machine by means of a controlled stop and start function. The method includes the following steps: - Before spinning stops, a negative pressure is generated on the yarn take-up device (6) so that the yarn (5) is properly tensioned during unwinding on the bobbin (15). - When the compressed air is restored, the yarn (5) is tensioned again by the yarn take-up device (6), and the excess yarn (5) is pulled out for a period of time, and then gradually released for winding before the pulled-out portion is retracted, as the yarn end is introduced into the spinning rotor (19).

16. The spinning method according to claim 10 or 11, further comprising the following step: - In order to reduce the occurrence of slack yarn (60) that will cause spinning interruption during shearing, the yarn take-up device (6) is opened before shearing begins. - Provide full or intermittent airflow to generate the necessary negative pressure to draw the slack yarn (60) into the tube (4) and thereby reduce any slack in the yarn (5).

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