JP2012107363A - Draft roller, draft machine and spinning machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a draft roller suitable for draft of fiber bundle for fine yarn or normal yarn.SOLUTION: A front top roller 20 includes a fiber contact part 30 whose diameter is substantially the same and with which fiber bundle 8 comes into contact on the outer periphery, and a reduced diameter part 31 whose diameter is smaller than that of the fiber contact part 30 at both ends in the axis direction of the fiber contact part 30. The width W4 of the fiber contact part 30 and the reduced diameter part 31 in the axis direction is equal to or more than 30 mm and equal to or less than 34 mm. The width W1 of the fiber contact part 30 in the axis direction is less than 18 mm.

Description

  The present invention mainly relates to the shape of a draft roller provided in a draft device.

  The spinning machine drafts a fiber bundle (sliver) with a draft device (stretches the fiber bundle) and twists the fiber bundle with a spinning device to obtain a spun yarn. This type of draft device is configured to include a plurality of draft rollers and draft the fiber bundles by niping (pinching) the fiber bundles with the draft rollers and rotationally driving the draft rollers.

  In recent years, since the spinning speed of the spinning device has increased, the rotational speed of the draft roller included in the draft device has also increased. As the rotational speed of the draft roller increases, the flow of air that flows along the surface of the draft roller (hereinafter referred to as an accompanying air flow) increases. Conventionally, the problem has been pointed out that the fibers of the fiber bundle are diffused by this accompanying air flow, and the degree of uniformity of the spun yarn produced is lowered.

  In this regard, Patent Document 1 discloses a front top roller of a draft device (a top roller disposed on the most downstream side of the draft rollers) in which both ends are largely cut off and the effective roller width is narrowed to almost half of the standard. ing. Patent Document 1 states that, even when the front top roller rotates at high speed, the fiber bundle is not affected by the accompanying air flow, and the fluff hardly scatters from the front of the front top roller to both sides.

  Further, Patent Document 2 forms a preventive wall for inserting the accompanying airflow accompanying rotation of the roller at the end portion between the rollers constituting the roller pair and preventing the fiber bundle from being sent out by drafting the accompanying airflow. A draft device provided with a gap for forming an air passage serving as an air flow is disclosed.

JP-A-7-126926 JP 2005-113274 A

  In a textile machine, the size and shape of each part are extremely important. For example, it is not uncommon for a slight difference in the shape of a draft roller to greatly affect the yarn quality. This is because the fibers constituting the fiber bundle are very thin and light, and the diffusion state of the fibers changes greatly with a slight change in the accompanying airflow in the vicinity of the draft roller. There are numerous options for how to set the size and shape of the drafting roller, so it is one of the technical issues to improve the yarn quality by improving the size and shape of the known drafting roller.

  However, in the above-mentioned Patent Document 1, the effective roller width of the front top roller is narrowed to almost half of the standard, and it is not described to what extent “near half” is included, and whether or not it includes the case of just half. I don't know. Thus, although the dimensions are extremely important in making the draft roller, it is unclear in the description of Patent Document 1 to what extent the effective roller width of “near half of the standard” includes. It is. Therefore, a person skilled in the art who wants to make a front top roller based on the description in Patent Document 1 can simply refer to the dimension “effective roller width after cutting both ends is 18 mm” described in the examples. is there.

  Patent Document 2 is an invention that focuses on the height and width of the stepped portion. The importance of the effective roller width is neither described nor suggested, and the width of the nip portion of the front top roller (referred to in Patent Document 1). However, only 18 mm is disclosed (FIG. 7) as an example of the effective roller width. Further, Patent Document 2 does not describe or suggest how to set the effective roller width to improve the yarn quality. Accordingly, those skilled in the art who have seen this Patent Document 2 do not think that there is room for optimizing the effective roller width, focusing on how to optimize the stepped portion.

  On the other hand, among those skilled in the art, when the effective roller width of the front top roller of the draft device is less than 18 mm, the fibers of the fiber bundle are likely to stick out from the effective roller width, and the yarn quality may become unstable. Are known. Of course, whether or not the fibers actually come out from the effective roller width of the front top roller differs depending on the draft conditions, so it cannot be generally stated. However, if the effective roller width of the front top roller is set to 18 mm or more, it is possible to prevent the fibers from sticking out under most conditions. That is, it can be said that a front top roller having an effective roller width of 18 mm or more is a highly versatile front top roller. Therefore, it is the common technical knowledge of those skilled in the art that the effective roller width of the front top roller should be 18 mm or more. Even if a person skilled in the art having this technical common knowledge touches Patent Documents 1 and 2, it is only necessary to set the effective roller width of the front top roller to 18 mm as described in the embodiments. It does not lead to the idea of making the diameter less than 18 mm.

  By the way, recently, as a result of the development of measuring instruments and improvement in the measurement accuracy of yarn quality, it has become possible to accurately evaluate the influence of the shape of the draft roller on the yarn quality. As a result of intensive studies by the present inventors in such a flow, in a spinning machine equipped with a draft device that employs a front top roller having an effective roller width of 18 mm or more, when a thick yarn is spun Although it was possible to improve the yarn quality, the yarn quality was not always improved as expected when spinning the middle and fine yarns. That is, the inventors of the present application are that the front top roller having an effective roller width of 18 mm or more is not necessarily in an optimum shape for drafting a fiber bundle for a thread thinner than the thick count (medium count or fine count thread). Suggested by the experiment.

  In this regard, Patent Document 1 and Patent Document 2 do not describe or suggest the idea of optimizing the size and shape of the front top roller according to the yarn count (thickness) or the like. In the first place, the accuracy of measuring the yarn quality was not so high at the time of filing of Patent Document 1 and Patent Document 2, and the versatility of the draft roller was emphasized, so it was necessary to use a front top roller with an effective roller width other than 18 mm. It was scarce.

  However, recently, as a result of the improvement of the measurement accuracy of the yarn quality as described above, the yarn quality has been demanded more severely than at the time of filing of Patent Document 1 and Patent Document 2. Therefore, it is considered that it is more suitable to provide a draft roller optimized according to the yarn count (thickness) than a general-purpose draft roller.

  The present invention has been made in view of the above circumstances, and a main object of the present invention is to provide a draft roller that is most suitable for drafting fiber bundles for middle and fine count yarns.

Means and effects for solving the problems

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

  According to a first aspect of the present invention, there is provided a draft roller of a draft device having the following configuration. That is, the draft roller is formed to have a diameter smaller than that of the fiber contact portion at a fiber contact portion that is formed to have a substantially constant diameter and a fiber bundle is brought into contact with an outer peripheral surface thereof, and at both axial ends of the fiber contact portion. And a reduced diameter portion. The axial width of the fiber contact portion and the reduced diameter portion is 30 mm or more and 34 mm or less. And the width | variety of the axial direction of the said fiber contact part is less than 18 mm.

  In this manner, by forming the reduced diameter portion at both ends of the fiber contact portion, the accompanying airflow generated along with the rotation of the draft roller can be released, so that the diffusion of the fiber bundle can be suppressed. And by making the width of the fiber contact portion less than 18 mm, the influence of the accompanying airflow can be reduced when the width of the drafted fiber bundle is narrow (when drafting the fiber bundle for a thread thinner than the thick count). As a result, the yarn quality can be improved.

  According to the 2nd viewpoint of this invention, the draft apparatus comprised as follows is provided. That is, the draft device includes the draft roller described above and an opposing roller that is disposed to face the draft roller and nips the fiber bundle with the fiber contact portion of the draft roller. And the width | variety of the axial direction of the said fiber contact part is wider in the range of 7 mm or more and 11 mm or less than the width | variety of the fiber bundle in the state nipped between the said fiber contact part and the said opposing roller.

  In this way, it is possible to prevent the fibers from coming out of the fiber contact portion by providing a margin in the width of the fiber contact portion with respect to the width of the fiber bundle being nipped. In addition, if the width of the fiber contact portion is too wide with respect to the width of the fiber bundle being nipped, the influence of the accompanying air flow becomes large and the fiber bundle is likely to spread. In this respect, when the margin of the width of the fiber contact portion with respect to the width of the fiber bundle is within the above range, the fiber bundle can be prevented from spreading due to the accompanying air flow. As described above, an optimum draft device can be provided by determining the width of the fiber contact portion of the draft roller in accordance with the width of the drafted fiber bundle.

  The draft device preferably drafts the fiber bundle so that the width of the fiber bundle in a state of being nipped between the fiber contact portion and the opposing roller is 7 mm or less.

  That is, the draft roller of the present invention is suitable for drafting a fiber bundle for a thread thinner than a thick count (medium count or fine count thread), so that the width of the fiber bundle nipped by the draft roller is 7 mm. Draft can be performed with particularly good quality by setting it below (corresponding to middle yarn, approximately 30 yarn).

  In the draft device, the draft roller is preferably a front top roller.

  That is, the front top roller is disposed on the most downstream side in the fiber bundle feeding direction among the rollers provided in the draft device and rotates at the highest speed, so that the influence of the accompanying airflow is the greatest. Therefore, by adopting the draft roller of the present invention as the front top roller, the effect of escaping the accompanying air flow and suppressing the diffusion of the fibers can be exhibited most remarkably.

  According to a third aspect of the present invention, there is provided a spinning machine including a plurality of spinning units each including the draft device described above and a spinning device that generates a spun yarn by spinning a fiber bundle drafted by the draft device. Provided.

  That is, the draft device of the present invention is particularly suitable for drafting fiber bundles for medium and fine yarns. Therefore, according to the spinning machine configured as described above, it is possible to improve the quality of the spun yarn produced by the spinning device.

  In the above spinning machine, the spinning device is preferably an air spinning device.

  That is, since the pneumatic spinning device can perform high-speed spinning, the draft roller also rotates at high speed, and the influence of the accompanying airflow tends to increase. Then, the effect which improves the quality of a thread | yarn can be exhibited notably by employ | adopting the draft roller of this invention which can escape the said accompanying airflow.

  In the spinning machine, the spinning device includes a nozzle holder, a hollow guide shaft body, a fiber guide portion that guides a fiber bundle into a spinning chamber formed between the nozzle holder and the hollow guide shaft body, It is preferable to provide.

  That is, in an air spinning device that requires accuracy of the state of the fiber bundle introduced into the spinning chamber, the fiber bundle drafted by the draft device is introduced in a stable state by the fiber guide, so that this spinning machine has a quality Stable spun yarn can be produced.

1 is a front view showing an overall configuration of a spinning machine according to an embodiment of the present invention. The side view of a spinning unit. Sectional drawing of a spinning apparatus. The perspective view of a front roller pair. The top view of a front roller pair. The figure which shows the result of having measured the yarn quality of the spun yarn spun when the nip width of the fiber bundle in the front roller pair is 6 mm. The figure which shows the result of having measured the yarn quality of the spun yarn spun when the nip width of the fiber bundle in the front roller pair is 10 mm.

  Next, a spinning machine (spinning machine) according to an embodiment of the present invention will be described with reference to the drawings. A spinning machine 1 as a spinning machine shown in FIG. 1 includes a large number of spindles (spinning unit 2) arranged in parallel. The spinning machine 1 includes a yarn splicing carriage 3, a blower box 80, and a prime mover box 5.

  As shown in FIG. 1, each spinning unit 2 includes, in order from upstream to downstream, a draft device 7, a spinning device 9, a yarn slack eliminating device (yarn storage device) 12, and a winding device 13. It is provided as a main configuration. In the present specification, “upstream” and “downstream” mean upstream and downstream in the traveling direction of the fiber bundle and yarn during spinning. Each spinning unit 2 spins the fiber bundle 8 sent from the draft device 7 by the spinning device 9 to generate the spun yarn 10, and winds the spun yarn 10 by the winding device 13 to form the package 45. It is configured as follows.

  The draft device 7 is provided near the upper end of the casing 6 of the spinning machine 1. The draft device 7 drafts (stretches the fiber bundle) a fiber bundle (sliver) 8 supplied from a sliver case (not shown) through a sliver guide until a predetermined width is reached. The fiber bundle 8 drafted by the draft device 7 is supplied to the spinning device 9.

  The spinning device 9 is for twisting the fiber bundle 8 supplied from the draft device 7 to generate the spun yarn 10. In the present embodiment, a pneumatic spinning device that twists the fiber bundle 8 using a swirling airflow is employed. As shown in FIG. 3, the spinning device 9 mainly includes a nozzle holder 34, a hollow guide shaft body 23, and a fiber guide (fiber guide portion) 22.

  A spinning chamber 26 is formed between the nozzle holder 34 and the hollow guide shaft body 23. The nozzle holder 34 is formed with an air ejection nozzle 27 that ejects air into the spinning chamber 26. The fiber guide 22 is formed with a yarn introduction port 21 for introducing the fiber bundle 8 into the spinning chamber 26. The air ejection nozzle 27 is configured to eject air into the spinning chamber 26 and generate a swirling airflow. With this configuration, the fiber bundle 8 supplied from the draft device 7 is guided into the spinning chamber 26 by the fiber guide 22 having the yarn introduction port 21. In the spinning chamber 26, the fiber bundle 8 is swung around the hollow guide shaft body 23 by the swirling airflow, and thereby twisted to become the spun yarn 10. The spun yarn 10 to which the twist is applied passes through a yarn passage 29 formed at the center of the hollow guide shaft 23 and is sent out of the spinning device 9 from a downstream yarn outlet (not shown).

  The yarn introduction port 21 is provided with a needle-like guide needle 22a with its tip directed toward the spinning chamber. The fiber bundle 8 introduced from the yarn introduction port 21 is guided into the spinning chamber 26 so as to be wound around the guide needle 22a. Thereby, the state of the fiber bundle 8 introduced into the spinning chamber 26 can be stabilized. Further, since the fiber bundle 8 is guided so as to be wound around the guide needle 22 a in this way, even if a twist is added to the fiber in the spinning chamber 26, the twist may propagate upstream from the fiber guide 22. Is prevented. Thereby, the twist by the spinning device 9 can be prevented from affecting the draft device 7.

  A yarn accumulating device 12 is provided downstream of the spinning device 9. As shown in FIG. 2, the yarn storage device 12 includes a yarn storage roller 14 and an electric motor 25 that rotationally drives the yarn storage roller 14.

  The yarn accumulating roller 14 is configured so that a certain amount of spun yarn 10 can be wound around the outer peripheral surface and temporarily accumulated. Then, the yarn storage roller 14 is rotated at a predetermined rotational speed while the yarn is wound around the outer peripheral surface of the yarn storage roller 14, thereby pulling the spun yarn 10 from the spinning device 9 at a predetermined speed and transporting it downstream. can do.

  The winding device 13 includes a cradle arm 71 supported so as to be swingable around a support shaft 73. The cradle arm 71 can rotatably support a bobbin 48 for winding the spun yarn 10.

  The winding device 13 includes a winding drum 72 and a traverse device 75. The winding drum 72 is configured to be able to be driven in contact with the outer peripheral surface of the package 45 formed by winding the bobbin 48 and the spun yarn 10 thereon. The traverse device 75 includes a traverse guide 76 that can be engaged with the spun yarn 10. In this configuration, the winding drum 72 is driven by an electric motor (not shown) while the traverse guide 76 is reciprocated by a driving means (not shown), thereby rotating the package 45 in contact with the winding drum 72 and spinning the yarn 10. It is designed to wind up while traversing.

  As shown in FIGS. 1 and 2, the yarn joining cart 3 includes a splicer (yarn joining device) 43, a suction pipe 44, and a suction mouth 46. The yarn splicing cart 3 is configured to travel on the rail 41 to the spinning unit 2 and stop when a yarn break or yarn cut occurs in a spinning unit 2. The suction pipe 44 sucks and captures the yarn end fed from the spinning device 9 and guides it to the splicer 43 while rotating in the vertical direction around the axis. The suction mouse 46 sucks the yarn end from the package 45 supported by the winding device 13 and guides it to the splicer 43 while rotating in the vertical direction about the shaft. The splicer 43 performs splicing between the guided yarn ends.

  A yarn clearer 52 is provided at a position between the spinning device 9 and the yarn storage device 12. The spun yarn 10 spun by the spinning device 9 passes through the yarn clearer 52 before being wound by the yarn accumulating device 12. The yarn clearer 52 monitors the traveling spun yarn 10 with a sensor (not shown) and detects a yarn defect (a part having an abnormality in the thickness of the spun yarn or a foreign matter contained in the yarn). A defect detection signal is transmitted to a unit controller (not shown).

  Upon receipt of the yarn defect detection signal, the unit controller immediately cuts the spun yarn 10 with the cutter 57, further stops the draft device 7, the spinning device 9 and the like, and also stops the winding in the winding device 13. Further, the unit controller sends a control signal to the yarn splicing carriage 3 so as to travel to the front of the spinning unit 2. The yarn splicing carriage 3 guides the yarn end on the spinning device 9 side and the yarn end on the package 45 side to the splicer 43 by the suction pipe 44 and the suction mouth 46, and performs the yarn splicing operation in the splicer 43. By the above yarn splicing operation, the portion of the yarn defect is removed, and the winding of the spun yarn 10 around the package 45 can be resumed. The cutter 57 may be omitted, and the spinning device 10 may be cut so as to tear by stopping the driving of the draft device 7 in a state where the driving of the winding device 13 is continued.

  Next, the draft device 7 will be described in detail.

  The draft device includes a plurality of draft rollers. Each of the draft rollers constitutes a pair of draft rollers. The draft device according to the present embodiment includes, in order from the upstream side, a back roller pair including draft rollers 16 and 66, a third roller pair including draft rollers 17 and 67, a middle roller pair including draft rollers 19 and 69, and a draft roller 20. , 70 and a pair of draft rollers, that is, a so-called four-wire draft device. A capacitor 28 for restricting the width of the fiber bundle is disposed between the third roller pair and the middle roller pair.

  In each draft roller pair, the draft roller on the front side of the spinning machine 1 is called a top roller, and the draft roller on the back side of the spinning machine 1 is called a bottom roller. The top rollers are, in order from the upstream side, a back top roller 16, a third top roller 17, a middle top roller 19 on which an apron belt 18 is mounted, and a front top roller 20. On the other hand, the bottom rollers are a back bottom roller 66, a third bottom roller 67, a middle bottom roller 69 on which an apron belt 68 is mounted, and a front bottom roller 70 in order from the upstream side.

  Each of the top rollers 16, 17, 19, and 20 is a roller having an outer peripheral surface made of an elastic member such as rubber. Each top roller 16, 17, 19, 20 is supported so as to be rotatable about its axis via a bearing (not shown). On the other hand, each of the bottom rollers 66, 67, 69, 70 is a metal roller, and is configured to be rotationally driven around its axis by a drive source (not shown). In each draft roller pair, the top roller and the bottom roller are arranged to face each other. The draft device 7 has urging means for urging the top rollers 16, 17, 19, 20 toward the bottom rollers 66, 67, 69, 70 facing the top rollers 16, 17, 19, 20. As a result, the outer peripheral surfaces of the top rollers 16, 17, 19, and 20 are in elastic contact with the outer peripheral surfaces of the bottom rollers 66, 67, 69, and 70. With this configuration, when the bottom rollers 66, 67, 69, and 70 are rotationally driven, the top rollers 16, 17, 19, and 20 that are in contact with the bottom rollers are also rotated.

  The draft device 7 nips the fiber bundle 8 between the rotating top rollers 16, 17, 19, 20 and the bottom rollers 66, 67, 69, 70, thereby bringing the fiber bundle 8 downstream. It is comprised so that it may convey toward. The draft device 7 is configured such that the rotational speed of the downstream draft roller pair increases. Accordingly, the fiber bundle 8 is stretched (drafted) while being transported between the draft roller pair and the draft roller pair, and accordingly, the width of the fiber bundle 8 becomes narrower toward the downstream side. By appropriately setting the rotational speed of each bottom roller 66, 67, 69, 70, the fiber regulation width by the condenser 28, etc., the degree to which the fiber bundle 8 is drafted can be changed, so that the draft was made to have a desired width. The fiber bundle 8 can be supplied to the spinning device 9. Thereby, in the spinning device 9, the spun yarn 10 having a desired count (thickness) can be spun.

  As described above, in the draft device 7, since the rotational speed of the downstream draft roller pair is higher, the rotational speed of the front roller pair, which is the most downstream draft roller pair, is extremely high. For this reason, the accompanying airflow generated in the vicinity of the front roller pair becomes strong, and the influence of the accompanying airflow on the yarn quality is increased. Therefore, in the draft device 7 of the present embodiment, the reduced diameter portion 31 is formed on the front top roller 20 in order to reduce the influence of the accompanying airflow generated in the vicinity of the pair of front rollers rotating at high speed.

  Hereinafter, the configuration of the front top roller 20 will be described in detail. As shown in FIGS. 4 and 5, the front top roller 20 includes a fiber contact portion 30 formed in a columnar shape having a substantially constant diameter, and the fiber contact portion 30 at both ends in the axial direction of the fiber contact portion 30. And a reduced diameter portion 31 formed in a columnar shape having a small diameter.

  The outer peripheral surface of the fiber contact portion 30 of the front top roller 20 is in contact with the outer peripheral surface of the front bottom roller 70 disposed so as to face the front top roller 20. As a result, as shown in FIG. 5, the fiber bundle 8 is nipped between the fiber contact portion 30 and the front bottom roller 70. On the other hand, a gap is formed between the reduced diameter portion 31 and the bottom roller 70.

  Next, the accompanying airflow generated in the vicinity of the front top roller 20 configured as described above will be described. As described above, the front top roller 20 is driven to rotate when the front bottom roller 70 facing the front top roller 70 is rotationally driven. Accordingly, the front top roller 20 and the front bottom roller 70 rotate in opposite directions. Therefore, as shown in FIG. 4, the accompanying airflow 90 generated by the rotation of the front top roller 20 and the accompanying airflow 91 generated by the rotation of the front bottom roller 70 become airflows facing each other, and the fiber bundle 8 Colliding near the entrance to the front roller pair.

  The accompanying accompanying airflows 90 and 91 become airflows flowing in directions parallel to the roller axes of the front top roller 20 and the front bottom roller 70 (hereinafter simply referred to as axial directions), and the axes of the front top roller 20 and the front bottom roller 70 It flows toward the direction end (that is, it flows so as to spread outward). And when the said accompanying airflow reaches | attains the axial direction edge part of the fiber contact part 30, the direction parallel to the running direction of the fiber bundle 8 passes through the clearance gap formed between the diameter-reduced part 31 and the front bottom roller 70. Flowing into. In this way, the flow of the accompanying airflow that flows in the axial direction can be released through the gap formed between the reduced diameter portion 31 and the front bottom roller 70. As a result, the flow of the accompanying airflow flowing in the axial direction is weakened, so that the fibers of the fiber bundle 8 can be prevented from spreading in the axial direction due to the accompanying airflow.

  Conventionally, it is considered that the shape of the reduced diameter portion 31 is important for the control of the accompanying airflow as described above. For example, Patent Document 2 describes how the width of the reduced diameter portion, the shape of the gap, etc. Describes whether to optimize. Further, for example, JP 2010-163702 describes examples in which the shape of the reduced diameter portion is variously devised. On the other hand, the shape and dimensions of the fiber contact portion 30 have not been considered very important. This is partly due to the fact that there is technical common sense that the width of the fiber contact portion 30 should be 18 mm or more, and that there is no room for devising the dimensions and shape of the fiber contact portion 30.

  However, as described above, as a result of repeated research by the inventors of the present application, in the spinning machine including the conventional front top roller 20 in which the axial width of the fiber contact portion 30 is 18 mm or more, the middle count and the fine count It became clear that the effect of improving the yarn quality could not be obtained when spinning the yarn. Therefore, the inventors of the present application conducted the following experiment in order to examine the influence of the shape of the fiber contact portion 30 on the yarn quality.

  That is, the inventors of the present application create front top rollers 20 in which the width of the fiber contact portion 30 in the roller axial direction is 18 mm, 17 mm, and 16 mm, and the spun yarn 10 by the spinning machine 1 that employs each front top roller 20. An experiment was carried out. FIG. 6 shows the result of measuring the yarn quality of the spun yarn 10 generated at this time. Note that A1 and A2 shown in FIG. 6 are yarn defects classified by a known class mat classification. FIG. 6 shows the number of detected yarn defects per 100 km of the spun yarn 10. It can be said that the smaller the number of detected yarn defects, the higher the quality of the spun yarn 10. In addition, when the experiment of FIG. 6 was performed, the width | variety of the fiber bundle 8 of the state which the fiber contact part 30 nipped was about 6 mm. This is a fiber width corresponding to about 30th spun yarn 10. Generally, the 30th yarn is the middle yarn.

  As shown in FIG. 6, yarn defects (particularly class mat A1) are reduced when the width of the fiber contact portion 30 is 17 mm or 16 mm, compared to when the width is 18 mm. In particular, when the width of the fiber contact portion 30 is set to 16 mm, it can be seen that the effect of reducing yarn defects is remarkably large. As described above, it was confirmed that the quality of the spun yarn 10 with the middle count was improved by employing the front top roller 20 having a width in the roller axial direction of the fiber contact portion 30 of less than 18 mm (for example, 17 mm or 16 mm). . Further, it was found that the front top roller 20 with the fiber contact portion 30 having a width of 16 mm is particularly effective for the spun yarn 10 having the middle count.

  As described above, conventionally, it has been thought that if the width of the fiber contact portion 30 is less than 18 mm, it is easy for the fibers to be squeezed out. Therefore, a draft top roller having a width of the fiber contact portion 30 of less than 18 mm is used. There was no. However, this time, it has been found that even if the width of the fiber contact portion 30 is less than 18 mm, not only the fibers do not stick out, but also an effect of improving the yarn quality may be obtained. That is, through the experiments by the inventors of the present application, the possibility that the front top roller 20 in which the width of the fiber contact portion 30 is less than 18 mm can be put into practical use has been revealed for the first time.

  As a result of further experiments, the inventors of the present application have found that the width of the non-nip portion is important in order to optimize the shape of the front top roller 20. Here, the non-nip portion refers to a portion of the fiber contact portion 30 where the fiber bundle 8 is not nipped. As shown in FIG. 5, the width of the fiber bundle 8 nipped by the fiber contact portion 30 is SW, and the axial width of the fiber contact portion 30 is W1. Further, the axial widths of the non-nip portions 32 and 33 formed outside the both ends in the width direction of the fiber bundle 8 are denoted by W2 and W3, respectively. As described above, since the non-nip portions 32 and 33 are formed at both ends of the fiber bundle 8, when simply referred to as “the width of the non-nip portion” or the like in the present specification, the non-nip portions at both ends. The sum of the widths of 32 and 33 (W2 + W3) shall be indicated.

  Hereinafter, the importance of the width of the non-nip portion, which has been clarified by the inventors, will be briefly described. That is, the wide width (W2 + W3) of the non-nip portion means that the fiber bundle 8 nipped by the fiber contact portion 30 and the reduced diameter portion 31 are separated in the axial direction. Since the reduced diameter portion 31 is formed to release the accompanying airflow, if the fiber bundle 8 and the reduced diameter portion 31 are too far apart, the accompanying airflow in the vicinity of the fiber bundle 8 cannot be released. It is considered that the fiber bundle 8 is easily diffused by the accompanying air flow. Therefore, by reducing the width (W2 + W3) of the non-nip portion to some extent, the accompanying airflow in the vicinity of the fiber bundle 8 can easily escape through the reduced diameter portion 31, so that the fiber bundle 8 becomes difficult to diffuse and the yarn quality. Is improved. However, on the other hand, if the width (W2 + W3) of the non-nip portion is too narrow, the fiber bundle 8 is likely to stick out from the fiber contact portion 30, and the yarn quality is rather deteriorated.

  Since the experimental result shown in FIG. 6 is when the width SW of the fiber bundle 8 is 6 mm, when the width W1 of the fiber contact portion 30 of the front top roller 20 is 18 mm, the width (W2 + W3) of the non-nip portion is 12 mm. Similarly, when the width W1 of the fiber contact portion 30 is 17 mm, the width of the non-nip portion (W2 + W3) is 11 mm, and when the width W1 of the fiber contact portion 30 is 16 mm, the width of the non-nip portion (W2 + W3). Is 10 mm. From the viewpoint of the width of the non-nip portion in the experimental result of FIG. 6, the yarn quality is improved when the width of the non-nip portion is 11 mm, compared to when the width of the non-nip portion is 12 mm. It can be seen that the yarn quality is particularly improved when the width of the non-nip portion is 10 mm. That is, the yarn quality is improved when the width W1 of the fiber contact portion 30 of the front top roller is 17 mm or less.

  FIG. 6 shows the case where the width SW of the fiber bundle 8 is 6 mm. As a result of repeated experiments by the inventors of the present application, if the width SW of the fiber bundle is 7 mm or less, the non-nip is shown. It was confirmed that the yarn quality was improved by setting the width of the portion to 11 mm or less.

  On the other hand, when the width SW of the fiber bundle 8 is thicker than 7 mm (a thick yarn, for example, when SW = 8 mm), the front top roller of the present invention (the front top roller having a width W1 of the fiber contact portion 30 of less than 18 mm). ), The fiber is likely to be pulled out, and the yarn quality may be deteriorated. Therefore, the front top roller 20 of the present invention is preferably used when the width SW of the fiber bundle 8 is 7 mm or less (this corresponds to a thread thinner than a thick count, that is, a middle count or a fine count yarn). is there. When the width SW of the fiber bundle 8 is thicker than 7 mm (when spinning a thick yarn), a conventional front top roller (a front top roller having a width W1 of the fiber contact portion 30 of 18 mm or more) may be used. .

  The inventors of the present application conducted an experiment in which the spun yarn 10 was spun with the width SW of the fiber bundle 8 set to 10 mm in order to investigate the relationship between the easiness of taking out the fibers and the width (W2 + W3) of the non-nip portion. The result is shown in FIG. When the width SW of the fiber bundle 8 is set to 10 mm as in this experiment (because the width SW is larger than 7 mm), the front top roller 20 of the present invention tends to cause fiber sticking and the yarn quality deteriorates. There is. Therefore, by looking at the relationship between the degree of deterioration of the yarn quality (number of yarn defects) and the width of the non-nip portion (W2 + W3) in this experiment, it is easy to remove the fibers and the width of the non-nip portion (W2 + W3). It is possible to clarify the relationship. From this point of view, the experimental results in FIG. 7 show that when the non-nip portion width (W2 + W3) is 7 mm and 8 mm, the number of yarn defects is relatively small, and the non-nip portion width (W2 + W3) is 6 mm. It can be seen that yarn defects (especially class mat A2) are increasing. From this experimental result, it can be said that when the width (W2 + W3) of the non-nip portion is 6 mm, the fibers of the fiber bundle 8 are likely to stick out from the fiber contact portion 30. Therefore, if the width (W2 + W3) of the non-nip portion is set to 7 mm or more, it is considered that the fibers can be prevented from sticking out.

In summary, when the width (W2 + W3) of the non-nip portion of the front top roller 20 is in the range of 7 mm or more and 11 mm or less, the fiber bundle 8 can be prevented from being pulled out from the fiber contact portion 30, and As a result of the fiber bundle 8 becoming difficult to diffuse due to the accompanying airflow, the yarn quality can be improved. That is, by setting the width W1 of the fiber contact portion 30 in the range shown below, a spun yarn 10 of good quality can be obtained:
SW + 7mm ≦ W1 ≦ SW + 11mm

  The width SW when the fiber bundle 8 is nipped at the fiber contact portion 30 of the front top roller 20 is determined by the setting of the draft device 7 (rotational speed of each draft roller pair, etc.). Therefore, in the spinning machine 1 of the present embodiment, a plurality of front top rollers 20 with different widths W1 of the fiber contact portions 30 are prepared, and the front is matched with the width SW of the fiber bundle 8 set by the draft device 7. The top roller 20 is used properly. According to this, even when the setting is changed, the width W1 of the fiber contact portion 30 can be within the above range, which is preferable. In the above embodiment, the case of spinning the middle count yarn (specifically, the case where the width SW of the fiber bundle 8 is 6 mm) has been described. However, the front top roller 20 of the present embodiment uses the fine count yarn. Even when spinning, the same effect can be obtained. That is, the front top roller 20 of the present embodiment exhibits the effect of improving the yarn quality when the width SW of the fiber bundle 8 is 7 mm or less (for example, SW = 7 mm, 6 mm, 5 mm, 4 mm, 3 mm, 2 mm, etc.). can do.

  By the way, since the surface of the top roller is an elastic member such as rubber, wear occurs by use. Thus, since the top roller is a consumable part, the top roller is configured to be replaceable in the draft device 7. Therefore, it is easy to replace the front top roller 20 according to the setting of the draft device 7.

  If the width W4 of the entire front top roller 20 (the axial width of the fiber contact portion 30 and the reduced diameter portion 31) is too wide, the roller may bend and the nip may be uneven. On the other hand, if the width W4 of the entire front top roller 20 is too narrow, the width of the reduced diameter portion 31 cannot be taken sufficiently, so that the effect of escaping the accompanying airflow cannot be fully exhibited. In this regard, according to experiments by the inventors of the present application, it has been confirmed that there is no particular problem if the width W4 of the entire roller is within a range of 30 mm to 34 mm. Therefore, in the front top roller 20 of the present embodiment, the width W4 of the entire roller is set to 30 mm or more and 34 mm or less. The experimental results shown in FIGS. 6 and 7 are experimental results obtained using the front top roller 20 having an overall width W4 of 32 mm.

  As described above, the front top roller 20 according to the present embodiment has a fiber contact portion 30 that has a substantially constant diameter and contacts the fiber bundle 8 with its outer peripheral surface, and both axial ends of the fiber contact portion 30. A reduced diameter portion 31 having a diameter smaller than that of the fiber contact portion 30. The axial width W4 of the fiber contact portion 30 and the reduced diameter portion 31 is 30 mm or more and 34 mm or less. And the width W1 of the axial direction of the fiber contact part 30 is less than 18 mm.

  In this way, by forming the reduced diameter portions 31 at both ends of the fiber contact portion 30, the accompanying airflow generated with the rotation of the front top roller 20 can be released, so that the diffusion of the fiber bundle 8 is suppressed. be able to. And by making the width of the fiber contact portion 30 less than 18 mm, the influence of the accompanying airflow is reduced when the width of the drafted fiber bundle 8 is narrow (when drafting the fiber bundle 8 for a thread thinner than the thick count). As a result, the yarn quality can be improved.

  Further, the draft device 7 of the present embodiment is arranged to face the front top roller 20 and the front top roller 20 and nip the fiber bundle 8 between the fiber contact portion 30 of the front top roller 20. And a front bottom roller 70. The axial width W1 of the fiber contact portion 30 is wider in the range of 7 mm to 11 mm than the width SW of the fiber bundle 8 nipped between the fiber contact portion 30 and the front bottom roller 70. .

  As described above, by allowing the width W1 of the fiber contact portion 30 to be larger than the width SW of the nipped fiber bundle 8, it is possible to prevent the fibers from coming out of the fiber contact portion 30. In addition, if the width of the fiber contact portion 30 is too wide with respect to the width of the fiber bundle 8 that is nipped, the effect of the accompanying air flow becomes large, and the fiber bundle 8 is likely to expand. In this regard, by making the margin of the width W1 of the fiber contact portion 30 with respect to the width SW of the fiber bundle 8 (that is, the width of the non-nip portion) within the above range, the fiber bundle 8 is prevented from spreading due to the accompanying airflow. Can do. As described above, the optimum draft device 7 can be provided by determining the width W1 of the fiber contact portion 30 of the front top roller 20 in accordance with the width of the fiber bundle 8 to be drafted.

  Further, the draft device 7 of the present embodiment may draft the fiber bundle 8 so that the width SW of the fiber bundle 8 nipped between the fiber contact portion 30 and the front bottom roller 70 is 7 mm or less. preferable.

  That is, the front top roller 20 of the present embodiment is suitable for drafting the fiber bundle 8 for a thread (medium count or fine count thread) thinner than a thick count, so that the front top roller 20 is nipped by the front top roller 20. When the width SW of the fiber bundle 8 is 7 mm or less (corresponding to a middle yarn, approximately 30 yarn), drafting can be performed with particularly good quality.

  The front top roller 20 is disposed on the most downstream side in the feeding direction of the fiber bundle 8 among the rollers provided in the draft device 7 and rotates at the highest speed, so that the influence of the accompanying airflow is the largest. Therefore, by adopting the draft roller of the present invention as the front top roller 20, the effect of escaping the accompanying air flow and suppressing the diffusion of the fibers can be exhibited most remarkably.

  The spinning machine 1 of the present embodiment includes a plurality of spinning units 2 including the draft device 7 and a spinning device 9 that spins the fiber bundle drafted by the draft device 7 to generate spun yarn. .

  That is, the draft device 7 according to the present embodiment is particularly suitable for drafting the fiber bundle 8 for the middle count and the fine count yarn. Therefore, according to the spinning machine 1 configured as described above, the quality of the spun yarn 10 generated by the spinning device 9 can be improved.

  In the spinning machine 1 of the present embodiment, the spinning device 9 is an air spinning device.

  That is, since the pneumatic spinning device can perform high-speed spinning, the draft roller also rotates at high speed, and the influence of the accompanying airflow tends to increase. Then, the effect which improves the quality of a thread | yarn can be exhibited notably by employ | adopting the draft roller of this invention which can escape the said accompanying airflow.

  In the spinning machine 1 of the present embodiment, the spinning device 9 includes a fiber in a spinning chamber 26 formed between the nozzle holder 34, the hollow guide shaft body 23, and the nozzle holder 34 and the hollow guide shaft body 23. And a fiber guide 22 for guiding the bundle 8.

  That is, in the pneumatic spinning device that requires accuracy of the state of the fiber bundle 8 introduced into the spinning chamber 26, the fiber bundle 8 is introduced in a stable state by the fiber guide 22, so that the spinning machine 1 has a stable quality. A spun yarn 10 can be generated.

  The preferred embodiment of the present invention has been described above, but the above configuration can be modified as follows, for example.

  The present invention can also be applied to draft devices of other types of spinning machines (for example, ring spinning machines).

  In the above embodiment, the spun yarn 10 is drawn from the spinning device 9 by winding the spun yarn 10 around the rotating yarn accumulating roller 14. In this regard, instead of the yarn accumulating device 12, a rotating delivery roller and a nip roller may be provided, and the spun yarn 10 may be nipped by the delivery roller and the nip roller to be pulled out from the spinning device 9. In this case, the yarn accumulating roller 14 may be disposed downstream of the delivery roller and the nip roller so as to absorb the looseness of the spun yarn 10 that occurs during the winding operation and the yarn joining operation.

  The needle-shaped guide needle 22a included in the fiber guide 22 can be omitted. In this case, the function of the guide needle 22 a may be realized by the edge of the downstream end of the fiber guide 22.

  The shape of the reduced diameter portion 31 is not limited to the cylindrical shape as shown in FIGS. 4, 5, and may be formed in a slope shape or a curved shape as disclosed in, for example, JP 2010-163702 A.

  In the above embodiment, the configuration in which the draft roller of the present invention is applied to the front top roller has been described. However, the present invention is not limited to this, and the configuration of the present invention may be applied to the front bottom roller. Further, the configuration of the present invention can be applied not only to the pair of front rollers but also to other draft rollers.

1 Spinning machine (spinning machine)
7 Draft device 8 Fiber bundle 9 Spinning device 10 Spinned yarn 20 Front top roller (draft roller)
30 Fiber contact part 31 Reduced diameter part

Claims (7)

A draft roller of a draft device,
A fiber contact portion having a substantially constant diameter and contacting the fiber bundle with its outer peripheral surface;
At both ends in the axial direction of the fiber contact portion, a reduced diameter portion formed with a smaller diameter than the fiber contact portion, and
Have
The axial width of the fiber contact portion and the reduced diameter portion is 30 mm or more and 34 mm or less,
A draft roller characterized in that an axial width of the fiber contact portion is less than 18 mm. A draft roller according to claim 1;
An opposing roller that is disposed opposite the draft roller and nips a fiber bundle with the fiber contact portion of the draft roller;
With
A draft device characterized in that the axial width of the fiber contact portion is wider in the range of 7 mm or more and 11 mm or less than the width of the fiber bundle nipped between the fiber contact portion and the opposing roller. . The draft device according to claim 2, wherein
A draft device characterized in that the fiber bundle is drafted so that the width of the fiber bundle in the nipped state between the fiber contact portion and the opposing roller is 7 mm or less. The draft device according to claim 2 or 3,
The draft device is characterized in that the draft roller is a front top roller. A draft device according to any one of claims 2 to 4;
A spinning device for producing a spun yarn by spinning a fiber bundle drafted by the draft device;
A spinning machine comprising a plurality of spinning units equipped with The spinning machine according to claim 5,
A spinning machine, wherein the spinning device is an air spinning device. The spinning machine according to claim 6, wherein
The spinning device is
A nozzle holder;
A hollow guide shaft,
A fiber guide for guiding a fiber bundle into a spinning chamber formed between the nozzle holder and the hollow guide shaft;
A spinning machine characterized by comprising:

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