JP2009243006A - Drafter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drafter which prevents a sliver present between back rollers and third rollers from becoming thinner by being drawn by more than an appropriate ratio or from loosening unpreparedly when the back rollers and the third rollers are decelerated, supplies a right quantity of fibers into a downstream side spinning device, and can deliver thread by self-spinning. <P>SOLUTION: The drafter 10 comprises a first drafting roller group used for a spinning machine 1 having a spinning unit spinning a sliver 20 and having front rollers 14 and middle rollers 13, a second drafting roller group having a plurality of back rollers (back rollers 11 and third rollers 12). To suspend spinning, the device cuts the sliver 20 between the first drafting roller group continuing to rotate and the second drafting roller group stopping rotating, and decelerates and stops the rotation of the back rollers while retaining a nearly fixed drafting ratio between the back rollers of the second drafting roller group. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technology of a draft device used in an air spinning machine.

  Conventionally, as a draft device used in an air spinning machine, for example, four lines in which draft rollers are arranged in the order of a back roller, a third roller, a middle roller, and a front roller from the upstream side to the downstream side in the running direction of the sliver There is a type draft device. Also, in view of diversification of draft ratio change accompanying the speed increase of the draft device, a draft device for driving the back roller and the third roller of each weight with independent drive sources has been developed.

  FIG. 4 is a plan view of a 4-wire draft device 100 used in an air spinning machine. In the draft device 100, when a defective portion of the yarn is detected on the downstream side of the draft device 100, it is necessary to temporarily stop spinning. At that time, the back roller 101 and the third roller 102 are stopped. At this time, the middle roller 103 and the front roller 104 on the downstream side of the third roller 102 continue to rotate. Therefore, as shown in FIG. 4, the sliver 105 is cut at the position of the capacitor 106 provided between the third roller 102 and the middle roller 103. As described above, when the spinning is temporarily suspended, the sliver 105 is cut between the third roller 102 and the middle roller 103 in order to automatically supply the sliver when spinning is resumed.

Next, when the spinning is resumed, the sliver 105 cut at the position of the condenser 106 by the rotation of the back roller 101 and the third roller 102 is automatically supplied to the middle roller 103 and passed through the front roller 104. By being supplied to the spinning device 107, the yarn is discharged by self-spinning. The same applies to draft devices other than the 4-wire draft device, such as a 5-wire draft device.
Japanese Patent Application Laid-Open No. 11-100727

  However, in the high-speed draft device 100 that drives the back roller 101 and the third roller 102 of each weight with independent driving sources, the spinning is temporarily suspended because the difference in the peripheral speed between the back roller 101 and the third roller 102 is large. In this case, there is a difference in deceleration time between the back roller 101 and the third roller 102. Then, a deviation occurs in the stop time between the back roller 101 and the third roller 102. For this reason, when the back roller 101 stops before the third roller 102, the third roller 102 is rotated even after the back roller 101 stops, so that the sliver 105 is interposed between the back roller 101 and the third roller 102. It is stretched and thinned beyond the proper ratio. Further, when the third roller 102 stops before the back roller 101, the back roller 101 is rotated even after the third roller 102 stops, so that the sliver 105 is interposed between the back roller 101 and the third roller 102. Unintentionally loosen without being stretched.

  When spinning is resumed in such a state and the yarn is discharged by self-spinning, even if the sliver 105 is automatically supplied to the middle roller 103, an appropriate amount of fiber is supplied into the downstream spinning device 107. There is a problem that the yarn cannot be removed by self-spinning.

  The present invention has been made to solve such a problem, and when the back roller and the third roller are decelerated, the sliver between the back roller and the third roller is stretched and thinned to an appropriate ratio or more. Another object of the present invention is to provide a drafting device that can prevent slack inadvertently, supply an appropriate amount of fiber into a spinning device on the downstream side, and perform yarn discharge by self-spinning.

  The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.

The draft device according to the first invention is used in a spinning machine having a spinning unit for spinning a sliver,
A first draft roller group having a front roller and a middle roller;
A second draft roller group having a plurality of back rollers;
In the draft device consisting of
When the spinning is interrupted, the sliver is cut between the first draft roller group that continues the rotation and the second draft roller group that stops the rotation,
The rotation of the back roller is decelerated and stopped while the draft ratio between the back rollers of the second draft roller group is kept substantially constant.

  The draft device according to the second invention is the draft device according to the first invention, wherein when the spinning is resumed, the draft ratio between the back rollers of the second draft roller group is kept substantially constant while the back roller is maintained. Accelerate the rotation of

  A draft device according to a third aspect is the draft device according to the first or second aspect, wherein each of the back rollers constituting the second draft roller group is driven by an independent drive source.

  A draft device according to a fourth aspect of the present invention is the draft device according to the third aspect of the present invention, wherein the driving source of each back roller is a stepping motor.

  As effects of the present invention, the following effects can be obtained.

  In the first invention, the draft is used in a spinning machine having a spinning unit for spinning a sliver, and includes a first draft roller group having a front roller and a middle roller, and a second draft roller group having a plurality of back rollers. In the apparatus, when the spinning is interrupted, the sliver is cut between the first draft roller group that continues to rotate and the second draft roller group that stops rotating, and between each back roller of the second draft roller group Since the rotation of the back roller is decelerated and stopped while the draft ratio of the second draft roller is kept substantially constant, the sliver between the back rollers of the second draft roller group is stretched to a proper ratio or narrower, or inadvertently Can be prevented from loosening. For this reason, when spinning is resumed, an appropriate amount of fiber can be supplied into the spinning device on the downstream side, and yarn can be discharged by self-spinning.

  In the second aspect of the invention, when the spinning is resumed, the rotation of the back roller is accelerated while maintaining the draft ratio between the back rollers of the second draft roller group substantially constant. It is possible to prevent the sliver between the back rollers of the draft roller group from being stretched to be thinner than an appropriate ratio, and to be slackened carelessly.

  In the third aspect of the invention, since each back roller constituting the second draft roller group is driven by an independent drive source, it becomes easy to keep the draft ratio between the back rollers constant.

  In the fourth invention, since the driving source of each back roller is a stepping motor, the driving source of each back roller can be controlled only by controlling the pulse frequency, and the draft ratio between the back rollers is kept constant. Easy to do.

  Hereinafter, a draft device 10 according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of a spinning machine 1 having a draft device 10 according to an embodiment of the present invention. The spinning machine 1 includes a spinning device 2, a yarn feeding device 3, a yarn clearer 4, a cutter 5, a yarn slack eliminating device 6, a winding device 7, a work carriage 8, and a draft device 10. To do. In the following description, a four-wire draft device will be described as the draft device 10, but the invention is not limited to the four-wire draft device, and the present invention can also be applied to a five-wire draft device or the like.

  The spinning device 2 is a pneumatic spinning device that produces a yarn (bound yarn) 21 by causing a swirling airflow to act on a sliver 20 stretched by a draft device 10.

  The yarn feeding device 3 is a device that feeds the yarn 21 manufactured by the spinning device 2 to the winding device 7. The yarn feeding device 3 includes a delivery roller 22 and a nip roller unit 23. The delivery roller 22 and the nip roller unit 23 are provided so as to be able to contact and separate. The yarn 21 is sandwiched between the delivery roller 22 and the nip roller unit 23, and is sent to the winding device 7 by the rotational drive of the delivery roller 22.

  The yarn clearer 4 is a yarn defect detection unit that detects a defect portion of the yarn 21 being sent to the winding device 7. The yarn clearer 4 is connected to the control unit 90 (FIG. 2), and transmits a yarn defect detection signal to the control unit 90 when a defect portion of the yarn 21 is detected. Specifically, the yarn clearer 4 detects the thickness of the yarn 21, and if the yarn 21 is out of the allowable range, the yarn 21 is assumed to have a defective portion. A defect detection signal is transmitted to the control unit 90. The cutter 5 is a yarn cutting unit that cuts the yarn 21 in which the defective portion is detected based on the detection signal of the yarn clearer 4.

  The yarn slack eliminating device 6 is a device that adjusts the winding tension of the yarn 21 before the yarn 21 spun by the spinning device 2 is wound by the winding device 7. The yarn slack eliminating device 6 wraps the yarn 21 around the outer peripheral surface of the slack eliminating roller 24 to absorb the tension fluctuation due to the traverse when forming the cone package, or the yarn 21 spun at the time of yarn splicing. Can be temporarily stored.

  The winding device 7 is a device that forms the package 31 by winding the yarn 21 manufactured by the spinning device 2 around the bobbin 30. The winding device 7 has a cradle arm 33 supported so as to be swingable about a support shaft 32, a winding drum 34 that rotates while contacting the peripheral surface of the package 31, and a yarn 21 with a predetermined width. And a traverse device (not shown) for traversing.

  The work carriage 8 is equipped with a device for splicing the upper yarn sent from the spinning device 2 and the lower yarn sucked and captured from the package 31. The work carriage 8 includes a yarn joining portion 40, a suction pipe 42, and a suction mouth 43. When the yarn 21 is cut by the cutter 5 based on the yarn defect detection signal of the yarn clearer 4, the work carriage 8 travels to the front of the spinning machine 1. The suction pipe 42 sucks and captures the yarn end fed from the spinning device 2 at the position shown by the two-dot chain line in FIG. 1 and guides it to the yarn joining portion 40 while rotating. The suction mouse 43 sucks the yarn end from the package 31 at the position indicated by the two-dot chain line in FIG. The yarn joining section 40 joins the upper yarn guided from the suction pipe 42 and the lower yarn guided from the suction mouth 43.

  Next, the draft device 10 will be described. FIG. 2 is a schematic diagram of the draft device 10. As shown in FIGS. 1 and 2, the draft device 10 includes four pairs of draft rollers that sandwich and extend a sliver 20. The four pairs of draft rollers are arranged along the running direction of the sliver 20, and include a middle roller 13 and a front roller 14 that constitute a first draft roller group, and a back roller that constitutes a second draft roller group. 11 and the third roller 12. An apron band 15 that is an endless belt made of synthetic rubber is wound around the middle roller 13. Further, a capacitor 50 is provided between the third roller 12 and the middle roller 13.

  The back roller 11 constituting the second draft roller group is a pair of upstream draft rollers in the draft device 10. The back roller 11 includes a back bottom roller 11A that is a driving roller and a back top roller 11B that is a driven roller. The back bottom roller 11A is a metal roller, and the back top roller 11B is a rubber roller. The back bottom roller 11 </ b> A is connected to the first drive source 16. When the back bottom roller 11A is rotated by driving the first drive source 16, the back top roller 11B is driven to rotate.

  The third roller 12 constituting the second draft roller group is adjacent to the downstream side of the back roller 11. The third roller 12 includes a third bottom roller 12A that is a driving roller and a third top roller 12B that is a driven roller. The third bottom roller 12A is a metal roller, and the third top roller 12B is a rubber roller. The third bottom roller 12 </ b> A is connected to the second drive source 17. When the third bottom roller 12A is rotated by driving the second drive source 17, the third top roller 12B is driven to rotate.

  The middle roller 13 constituting the first draft roller group is disposed adjacent to the downstream side of the third roller 12, and continues to rotate even when the yarn is cut. The middle roller 13 includes a middle bottom roller 13A that is a driving roller and a middle top roller 13B that is a driven roller. The middle bottom roller 13A is a metal roller, and the middle top roller 13B is a rubber roller. The middle roller 13 is constituted by a line shaft common to all the spindles, and always rotates.

  The front roller 14 constituting the first draft roller group is a downstream draft roller in the draft device 10. The front roller 14 includes a front bottom roller 14A that is a driving roller and a front top roller 14B that is a driven roller. The front bottom roller 14A is a metal roller, and the front top roller 14B is a rubber roller. The front roller 14 is constituted by a line shaft common to all the spindles, and always rotates.

  The capacitor 50 is provided between the third roller 12 and the middle roller 13 and regulates the width of the drafted sliver.

  As shown in FIG. 2, each drive source of the draft device 10 is connected to the control unit 90. Driving sources (16, 17) for the back roller 11 and the third roller 12 constituting the second draft roller group are provided independently for each weight. The control unit 90 controls the first drive source 16 and the second drive source 17 so that the back roller 11 and the third roller 12 change the circumferential speed shown in FIG. The first drive source 16 and the second drive source 17 are stepping motors. The first drive source 16 and the second drive source 17 are not limited to stepping motors, and may be other drive sources (for example, servo motors) as long as the back roller 11 and the third roller 12 can be driven. It doesn't matter. The first drive source 16 and the second drive source 17 are connected to drivers (16A, 17A). The drivers (16 </ b> A, 17 </ b> A) control the rotation of the first drive source 16 and the second drive source 17 according to a command signal from the control unit 90. Thus, in the draft device 10, the back roller 11 and the third roller 12 are driven by independent driving sources (first driving source 16 and second driving source 17) for each weight. The middle roller 13 and the front roller 14 can also be independent drive sources for each weight.

  Next, processing steps in the draft device 10 will be described. As shown in FIG. 2, the back roller 11, the third roller 12, the middle roller 13, and the front roller 14 rotate at different peripheral speeds according to the set draft ratios between the draft rollers. The back roller 11, the third roller 12, the middle roller 13 disposed on the upstream side of the draft device 10, and the front disposed on the most downstream side of the draft device 10 so that the sliver 20 conveyed from the upstream side is gradually extended. The circumferential speed is set to increase in the order of the rollers 14.

  Next, control of the draft device 10 will be described. FIG. 3 is a graph showing changes in the peripheral speed of the back roller 11 and the third roller 12 of the draft device 10. A two-point difference line is a change in the peripheral speed of the back roller 11, and a solid line is a change in the peripheral speed of the third roller 12.

  First, control of acceleration rotation of the back roller 11 and the third roller 12 will be described. The controller 90 transmits a command pulse signal having a predetermined pulse frequency to the first driver 16A and the second driver 17A in order to accelerate and rotate the back roller 11 and the third roller 12. Here, the predetermined pulse frequency is such that the back roller 11 and the third roller 12 accelerate substantially linearly while maintaining the peripheral speed ratio of both draft rollers constant, and the operation speed (V1, V2) is set. The peripheral speed ratio between the back roller 11 and the third roller 12 is determined by the relationship between the acceleration time t1 and the operating speeds (V1, V2) of both draft rollers. The operating speeds (V1, V2) of both draft rollers are determined by the draft ratio between the back roller 11 and the third roller 12. Note that the predetermined pulse frequency is controlled so that the first drive source 16 and the second drive source 17 have a load that does not cause step-out.

  When the first driver 16A and the second driver 17A receive the command pulse signal from the controller 90, the first driver 16A and the second driver 17A convert the current to the first drive source 16 and the second drive source 17 and convert the current to the current corresponding to the command pulse signal. Shed. The first drive source 16 and the second drive source 17 accelerate the back roller 11 and the third roller 12 according to the current flowing from the first driver 16A and the second driver 17A. The back roller 11 and the third roller 12 rotate while being accelerated by the acceleration drive of the first drive source 16 and the second drive source 17. Then, the back roller 11 and the third roller 12 rotate at the operating speeds (V1, V2) of the draft rollers after the acceleration time t1.

  Next, the control of the reduced speed rotation of the back roller 11 and the third roller 12 when spinning is interrupted will be described. The controller 90 transmits a command pulse signal having a predetermined pulse frequency to the first driver 16A and the second driver 17A in order to rotate the back roller 11 and the third roller 12 at a reduced speed. Here, the predetermined pulse frequency is such that the back roller 11 and the third roller 12 decelerate substantially linearly while maintaining the peripheral speed ratio of both draft rollers constant, and the circumferential speeds of both draft rollers at a predetermined deceleration time t2. The speed is set to zero. The peripheral speed ratio between the back roller 11 and the third roller 12 is determined by the relationship between the deceleration time t2 and the operating speeds (V1, V2) of both draft rollers. Note that the predetermined pulse frequency is controlled so that the first drive source 16 and the second drive source 17 have a load that does not cause step-out.

  When the first driver 16A and the second driver 17A receive the command pulse signal from the controller 90, the first driver 16A and the second driver 17A convert the current to the first drive source 16 and the second drive source 17 and convert the current to the current corresponding to the command pulse signal. Shed. The first drive source 16 and the second drive source 17 drive the back roller 11 and the third roller 12 at a reduced speed according to the current flowing from the first driver 16A and the second driver 17A. The back roller 11 and the third roller 12 rotate while being decelerated by the deceleration drive of the first drive source 16 and the second drive source 17. Then, the back roller 11 and the third roller 12 stop rotating after the deceleration time t2.

  As described above, in the present invention, the back roller 11 and the third roller 12 are accelerated to the operating speeds (V1, V2) of both draft rollers in the acceleration time t1 while keeping the peripheral speed ratio of both draft rollers constant. That is, the back roller 11 and the third roller 12 accelerate to the operating speeds (V1, V2) of both the draft rollers while keeping the draft ratio between the two draft rollers constant. When spinning is interrupted when the yarn 21 is cut, the speed is reduced so that both draft rollers stop at a deceleration time t2 while keeping the peripheral speed ratio of both draft rollers constant. That is, the back roller 11 and the third roller 12 are decelerated and stopped while keeping the draft ratio between the two draft rollers constant. Accordingly, the peripheral speeds of the back roller 11 and the third roller 12 are controlled so as to have a substantially trapezoidal shape as shown in FIG.

Next, the control of the draft device 10 and the state of the sliver 20 when the yarn clearer 4 detects a defective portion of the yarn 21 will be described.
As shown in FIG. 1, when the yarn clearer 4 detects a defect portion in the yarn 21 being sent to the winding device 7, it transmits a yarn defect detection signal to the control unit 90 (FIG. 2). When receiving the yarn defect detection signal, the control unit 90 transmits a control signal for cutting the yarn 21 to the cutter 5. When the cutter 5 receives the control signal, the cutter 5 cuts the yarn 21.

  As shown in FIG. 2, when the control unit 90 transmits a control signal for cutting the yarn 21 to the cutter 5, the control unit 90 transmits a command pulse signal to the first driver 16A and the second driver 17A. . Here, the control unit 90 gradually transmits while maintaining a constant ratio between the pulse frequency of the command pulse signal transmitted to the first driver 16A and the pulse frequency of the command pulse signal transmitted to the second driver 17A. Reduce the pulse frequency of the command pulse signal. Thereby, the current value converted by the first driver 16A and the second driver 17A gradually decreases. Then, as the current flowing through the first drive source 16 and the second drive source 17 decreases, the drive speeds of the first drive source 16 and the second drive source 17 gradually decrease, and the back roller 11, In addition, the peripheral speed of the third roller 12 gradually decreases. At this time, since the ratio of the currents flowing through the first drive source 16 and the second drive source 17 is constant, the peripheral speed between the back roller 11 and the third roller 12 is constant at the peripheral speed ratio between the two draft rollers. Gradually slow down while holding.

  On the other hand, the middle roller 13 and the front roller 14 continue to rotate. Therefore, when the back roller 11 and the third roller 12 are stopped, the sliver 20 is stretched between the third roller 12 and the middle roller 13 and finally cut in the vicinity of the capacitor 50.

  The sliver 20 is drafted at a normal draft ratio until the rotation of the back roller 11 and the third roller 12 stops. As described above, the back roller 11 and the third roller 12 decelerate while holding the peripheral speed ratio of both draft rollers constant, and stop substantially simultaneously. Therefore, the back roller 11 and the third roller 12 are rotated at a reduced speed. The draft ratio between them is also kept constant. As described above, the cut sliver 20 on the side of the third roller 12 (upstream side of the draft device 10) may be stretched or loosened between the back roller 11 and the third roller 12 to an appropriate ratio or more. Therefore, the spinning can be interrupted in a state where the amount of fibers necessary for the yarn extraction by self-spinning is provided.

  Next, a description will be given of a case where the yarn is discharged by self-spinning in order to resume spinning. As described above, when the back roller 11 and the third roller 12 are stopped and the sliver 20 is cut in the vicinity of the capacitor 50, the yarn is extracted by self-spinning in order to resume spinning. Here, the yarn discharging by self-spinning is to perform yarn discharging by operating both a swirl flow generating nozzle and a yarn discharging nozzle (not shown) in the spinning device 2 at the start of spinning. Therefore, in order to perform yarn discharge by self-spinning, it is necessary to supply an appropriate amount of fiber necessary for yarn discharge into the spinning device 2.

  When threading is performed by self-spinning, the cut sliver 20 on the side of the third roller 12 (upstream side of the draft device 10) automatically rotates and restarts the back roller 11 and the third roller 12. Supplied to the middle roller 13. Then, it is fed into the spinning device 2 via the front roller 14. Therefore, the sliver 20 needs a sufficient amount of fiber when it is supplied to the middle roller 13, and if the sliver 20 is stretched more than an appropriate ratio between the back roller 11 and the third roller 12, the middle roller 13 and the front roller 14 are further stretched so that they are too thin before being fed into the spinning device 2 and do not have the amount of fibers necessary for yarn discharge. When spinning is resumed between the back roller 11 and the third roller 12 with the sliver 20 slackened, a large amount of the sliver 20 is supplied into the spinning device 2 to cause nozzle clogging. Cause.

  In the case of the present invention, the cut sliver 20 on the side of the third roller 12 (upstream side of the draft device 10) is not stretched to an appropriate ratio or more when it is supplied to the middle roller 13. At this stage, the fiber has a sufficient amount of fiber, and even if it is further stretched by the middle roller 13 and the front roller 14, it has a sufficient amount of fiber necessary for yarn extraction. For this reason, in this invention, since the suitable fiber quantity can be supplied in the spinning apparatus 2, the thread | yarn discharge | emission by self-spinning can be performed easily.

  In the above description, the 4-wire draft device has been described. However, the present invention may be used for a draft device other than the 4-wire draft device (for example, a 5-wire draft device). In the 5-wire draft device, another back roller is added upstream of the back roller of the 4-wire draft device. In this case, the second draft roller group has three pairs of back rollers. In the case of such a 5-wire draft device, the peripheral speed of the three pairs of back rollers is controlled, and the rotation of the three pairs of back rollers is decelerated while maintaining the draft ratio between the back rollers substantially constant. You may stop at the same time.

1 is a schematic view of a spinning machine 1 having a draft device 10. 1 is a schematic diagram of a draft device 10. FIG. The graph which shows the peripheral speed change of the back roller 11 of the draft apparatus 10, and the 3rd roller 12. FIG. The top view of the 4-wire type draft apparatus 100 used for the conventional air spinning machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Spinning machine 10 Draft apparatus 11 Back roller (2nd draft roller group)
12 Third roller (second draft roller group)
13 Middle roller (first draft roller group)
14 Front roller (first draft roller group)
16 First drive source 17 Second drive source 20 Sliver

Claims (4)

Used in spinning machines with spinning units that spin sliver,
A first draft roller group having a front roller and a middle roller;
A second draft roller group having a plurality of back rollers;
In the draft device consisting of
When the spinning is interrupted, the sliver is cut between the first draft roller group that continues the rotation and the second draft roller group that stops the rotation,
A draft device characterized in that the rotation of the back roller is decelerated and stopped while the draft ratio between the back rollers of the second draft roller group is kept substantially constant.   2. The draft device according to claim 1, wherein when spinning is resumed, the rotation of the back roller is accelerated while the draft ratio between the back rollers of the second draft roller group is kept substantially constant.   The draft device according to claim 1 or 2, wherein each back roller constituting the second draft roller group is driven by an independent drive source.   The draft device according to claim 3, wherein a driving source of each of the back rollers is a stepping motor.

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