JP2020172363A - Yarn unwinding assist device - Google Patents

Abstract

To provide a yarn unwinding assist device which can effectively suppress increase of unwinding tensile force.SOLUTION: A yarn unwinding assist device 20 assists unwinding of a yarn Y from a yarn feeding bobbin SB. The yarn unwinding assist device 20 includes a guide cylinder 50 arranged to cover a core tube of the yarn feeding bobbin SB. On an inner peripheral surface 52a of the guide cylinder 50, a low friction material layer 61 is provided which has a dynamic friction coefficient of 0.1 or more and 0.25 or less with respect to a cotton yarn.SELECTED DRAWING: Figure 4

Description

The present invention relates to a yarn unwinding assisting device that assists in unwinding a yarn from a bobbin.

Conventionally, an automatic winder that winds a thread on a winding bobbin while unwinding the thread from the thread feeding bobbin is known. Here, a balloon is formed around the thread feeding bobbin by the thread unwound from the thread feeding bobbin. The balloon is a part where the thread unwound from the thread feeding bobbin is swung around by centrifugal force. Here, when the unwinding speed of the thread from the yarn feeding bobbin is increased, the solution is particularly in the latter half of unwinding (for example, after the time when the remaining unwinding amount of the yarn feeding bobbin becomes a three-quarter ball). Thread breakage may occur due to the increase in bobbin tension.

Therefore, the automatic winder is provided with a thread unwinding assisting device that assists the unwinding of the thread in order to physically suppress the balloon. The thread unwinding assisting device includes a guide tube that covers the core tube of the thread feeding bobbin. The thread unwinding assisting device prevents the thread from being excessively swung by bringing the guide tube into contact with the balloon. A thread unwinding assisting device including such a guide cylinder is described in, for example, Patent Document 1.

Japanese Unexamined Patent Publication No. 2013-67459

In the thread unwinding assisting device as described above, there is room for further improvement in suppressing the increase in unwinding tension described above.

Therefore, one aspect of the present invention is to provide a yarn unwinding assisting device capable of effectively suppressing an increase in unwinding tension.

One aspect of the present invention is a thread unwinding assisting device that assists in unwinding a thread from a bobbin, and includes a guide cylinder arranged so as to cover the core tube of the bobbin, and the inner peripheral surface of the guide cylinder , A low friction portion having a coefficient of dynamic friction with respect to cotton yarn of 0.1 or more and less than 0.25 is provided. For example, the cotton yarn is a yarn having an English cotton count of Ne30.

In this yarn unwinding assisting device, a low friction portion having a coefficient of dynamic friction with respect to cotton yarn of 0.1 or more and less than 0.25 is provided on the inner peripheral surface of the guide cylinder. Here, it is considered that the cause of the increase in the unwinding tension of the thread is the friction between the unwound thread from the bobbin and the thread wound around the bobbin (the thread before unraveling). According to the guide cylinder, the low friction portion makes the slipperiness of the thread on the inner circumference of the guide cylinder different from that of the conventional material (for example, the salt bath soft-nitrided pickled steel sheet having a dynamic friction coefficient of 0.25). Can be improved in comparison. As a result, the movement of the thread unwound from the bobbin in the guide cylinder can be promoted, and the frictional resistance generated between the thread unwound from the bobbin and the thread wound around the bobbin (the thread before unraveling) is reduced. it can. As a result, the increase in unwinding tension can be effectively suppressed.

The guide cylinder has a cylindrical first cylinder portion extending along a predetermined reference axis and a bobbin out of both ends along the reference axis in the first cylinder portion while extending along the reference axis. It has a second cylinder portion connected to the upstream end portion of the thread unwound from the traveling direction, and the second cylinder portion is the first from the end portion on the side connected to the first cylinder portion. It has a tapered shape that gradually expands toward the end opposite to the end connected to the cylinder, even if the low friction portion is provided at least on the inner peripheral surface of the first cylinder. Good. According to this configuration, the slipperiness of the yarn can be appropriately improved in the first cylinder portion which is a contact portion with the yarn introduced into the guide cylinder via the second cylinder portion. As a result, the movement of the thread unwound from the bobbin in the guide cylinder can be effectively promoted.

The low friction portion may be provided on both the inner peripheral surface of the first cylinder portion and the inner peripheral surface of the second cylinder portion. According to this configuration, the slipperiness of the yarn can be improved on the inner circumferences of both the first cylinder portion and the second cylinder portion. As a result, the movement of the unwound thread from the bobbin in the guide cylinder can be promoted even more effectively.

The inner peripheral surface of the second tubular portion may be provided with a high friction portion having a coefficient of dynamic friction with respect to the cotton thread larger than that of the low friction portion. According to this configuration, the occurrence of sluffing can be suppressed by the high friction portion and the increase in the unwinding tension can be suppressed by the low friction portion according to the progress of unwinding of the yarn from the bobbin.

According to one aspect of the present invention, it is possible to provide a yarn unwinding assisting device capable of effectively suppressing an increase in unwinding tension.

FIG. 1 is a front view of an automatic winder including a yarn unwinding assisting device according to an embodiment. FIG. 2 is a side view of the take-up unit. FIG. 3 is a side view of the thread unwinding assisting device around the guide cylinder. FIG. 4 is a cross-sectional view of the guide cylinder. FIG. 5 is a diagram showing the time change of the guide tension in the first half of unwinding for the examples and the comparative examples. FIG. 6 is a diagram showing the time change of the guide tension in the latter half of the unraveling of the examples and the comparative examples. FIG. 7 is a cross-sectional view of a first modification of the guide cylinder. FIG. 8 is a cross-sectional view of a second modification of the guide cylinder.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicate description will be omitted.

As shown in FIG. 1, the automatic winder 1 includes a plurality of winding units 3 arranged side by side, a machine base control device 5, and a ball lifting device 7.

The machine stand control device 5 can communicate with each of the plurality of winding units 3. The operator of the automatic winder 1 can collectively manage a plurality of winding units 3 by appropriately operating the machine base control device 5. The machine stand control device 5 is provided with a display screen 5a and an input key 5b. The display screen 5a can display information about the setting contents and / or the state of the winding unit 3. The setting work of the take-up unit 3 is performed when the operator performs an appropriate operation using the input key 5b.

Each of the plurality of winding units 3 winds the yarn Y on the winding bobbin WB while unwinding the yarn Y from the yarn feeding bobbin (bobbin) SB and swinging the yarn Y. In this way, the take-up unit 3 forms the package P. The thread Y may include a core thread. The core yarn is, for example, a monofilament yarn or the like.

When the package P is fully wound (a state in which a specified amount of yarn is wound) in each of the plurality of winding units 3, the ball lifting device 7 travels to the position of the winding unit 3 and is fully wound. The winding package is removed from the winding unit 3, and an empty winding bobbin WB is set in the winding unit 3.

Next, the configuration of the take-up unit 3 will be described with reference to FIG. As shown in FIG. 2, each of the plurality of winding units 3 includes a unit control unit 10, a yarn feeding device 12, and a winding device 14.

The unit control unit 10 includes, for example, a processor such as a CPU (Central Processing Unit) and a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory). A program for controlling each configuration of the take-up unit 3 is stored in the memory. The processor executes a program stored in memory. The unit control unit 10 controls each configuration of the take-up unit 3 in cooperation with hardware and software. The unit control unit 10 is configured to be able to communicate with the machine base control device 5. As a result, the operation of the plurality of winding units 3 provided in the automatic winder 1 can be centrally managed by the machine base control device 5.

The thread feeding device 12 is a support mechanism that supports the thread feeding bobbin SB mounted on the transport tray at a predetermined position. The thread Y is unwound from the thread feeding bobbin SB, and the thread Y is pulled out from the thread feeding bobbin SB upward. As a result, the yarn feeding device 12 supplies the yarn Y. The yarn feeding device 12 is not limited to the transport tray type, and may be, for example, a magazine type.

The take-up device 14 includes a cradle 16 and a take-up drum 18. The cradle 16 has a pair of rotary supports (not shown). The cradle 16 rotatably supports the take-up bobbin WB (or package P) by sandwiching the take-up bobbin WB with the rotation support portion. The cradle 16 can be switched between a state in which the supporting package P is in contact with the take-up drum 18 and a state in which the package P is separated from the take-up drum 18.

The take-up drum 18 traverses the thread Y on the surface of the package P and rotates the package P. The take-up drum 18 is rotationally driven by a drum drive motor (not shown). The package P is driven to rotate by rotationally driving the take-up drum 18 with the outer peripheral surface of the package P in contact with the take-up drum 18. Further, a spiral twill groove is formed on the outer peripheral surface of the take-up drum 18. The thread Y unwound from the thread-feeding bobbin SB is wound around the surface of the package P while being traversed by a twill groove with a constant width. Thereby, the package P having a constant winding width can be formed.

Each of the plurality of winding units 3 includes the yarn unwinding assisting device 20 and the tension applying device 22 in this order from the yarn feeding device 12 side in the yarn traveling path between the yarn feeding device 12 and the winding device 14. A tension detection device 24, a thread splicing device 26, a thread monitoring device 28, and a wax applying device 30 are provided. A first capture guide device 32 and a second capture guide device 34 are arranged in the vicinity of the thread joining device 26.

The thread unwinding assisting device 20 includes a guide cylinder 50 arranged so as to cover the core tube of the thread feeding bobbin SB. The guide cylinder 50 has a substantially tubular shape, and is arranged so as to come into contact with the balloon of the yarn Y formed on the upper portion of the yarn layer of the yarn feeding bobbin SB. The balloon is a portion where the thread Y unwound from the thread feeding bobbin SB is swung around by centrifugal force. By bringing the guide cylinder 50 into contact with the balloon, it is possible to prevent the thread Y from being excessively swung by coming into contact with the thread Y of the balloon portion. As a result, the thread Y can be appropriately unwound from the thread feeding bobbin SB.

The tension applying device 22 applies a predetermined tension to the traveling thread Y. In the present embodiment, the tension applying device 22 is a gate type in which movable comb teeth are arranged with respect to fixed comb teeth. The comb teeth on the movable side are urged so that the comb teeth are in mesh with each other. The tension applying device 22 applies tension to the thread Y by passing the thread Y while bending between the comb teeth in the meshed state. The operation of the tension applying device 22 is controlled by the unit control unit 10.

The tension detection device 24 detects (measures) the tension of the traveling thread Y between the thread feeding device 12 and the winding device 14. The tension detection device 24 outputs a tension measurement signal indicating a measured value of the tension of the thread Y to the unit control unit 10.

When the yarn Y is split between the yarn feeder 12 and the take-up device 14 for some reason, the yarn joining device 26 includes the yarn Y (bobbin thread) on the yarn feeder 12 side and the take-up device. The thread Y (upper thread) on the 14 side is spliced. In the present embodiment, the yarn splicing device 26 is configured as a splicer device that twists yarn ends with each other by a swirling air flow generated by compressed air.

The thread monitoring device 28 monitors the state of the thread Y traveling on the thread path, and detects the presence or absence of a thread defect based on the monitored information. The thread monitoring device 28 detects, for example, an abnormality in the thickness of the thread Y and / or a foreign substance contained in the thread Y as a thread defect. The thread monitoring device 28 also detects thread breakage, that is, the presence or absence of thread Y in the thread path. A cutter 29 for cutting the yarn Y is provided in the vicinity of the yarn monitoring device 28. The cutter 29 is operated by the thread monitoring device 28.

The wax applying device 30 is arranged between the winding device 14 and the yarn monitoring device 28. The wax applying device 30 applies wax to the yarn Y traveling from the thread monitoring device 28 toward the winding device 14.

Next, the details of the configuration of the thread unwinding assisting device 20 will be described. As shown in FIG. 3, the thread unwinding assisting device 20 assists the unwinding of the thread Y from the thread feeding bobbin SB above the thread feeding bobbin SB supported in an upright state by the thread feeding device 12. .. The yarn unwinding assisting device 20 controls the size of the balloon formed by the yarn Y unwound from the yarn feeding bobbin SB, and applies an appropriate tension to the yarn Y.

Specifically, the thread unwinding assisting device 20 includes a guide cylinder 50, a fixed cylinder 54, and an elevating mechanism 56. The fixed cylinder 54 is a substantially cylindrical member having upper and lower ends open. The fixed cylinder 54 is fixed to the frame of the winding unit 3 via the holder 58. A thread guide 55 is provided at the lower end of the fixed cylinder 54.

The guide cylinder 50 is a substantially tubular member having upper and lower ends open. The guide cylinder 50 is supported by the elevating mechanism 56 via the holder 57. The lower part of the fixed cylinder 54 is inserted inside the upper part of the guide cylinder 50. The guide cylinder 50 is moved up and down by the elevating mechanism 56 so as to cover the upper part of the thread feeding bobbin SB. The central axis of the thread feeding bobbin SB coincides with the central axis of the fixed cylinder 54 and the guide cylinder 50. The thread Y unwound from the thread feeding bobbin SB passes through the internal space of the guide cylinder 50.

Further, the yarn unwinding assisting device 20 includes a sensor that detects the height of the chase portion T of the yarn feeding bobbin SB. The position of the chase portion T is lowered by unwinding the thread Y. The elevating mechanism 56 lowers the guide cylinder 50 according to the height of the chase portion T detected by the sensor. As a result, the guide cylinder 50 can be lowered (movable) according to the unwinding of the thread Y from the thread feeding bobbin SB.

The fixed cylinder 54 regulates the spread of the balloon in a fixed state. The guide cylinder 50 moves following the unwinding of the yarn Y from the yarn feeding bobbin SB to regulate the spread of the balloon. In this way, the fixed cylinder 54 and the guide cylinder 50 assist the unwinding of the thread Y by restricting the spread of the balloon.

Next, the details of the guide cylinder 50 will be described. As described above, the guide cylinder 50 shown in FIGS. 3 and 4 assists in unwinding the yarn Y from the yarn feeding bobbin SB. The guide cylinder 50 is formed of, for example, a salt bath soft-nitrided pickled steel plate (SPHC-P). The guide cylinder 50 includes a first cylinder portion 51 and a second cylinder portion 52. The first tubular portion 51 has a cylindrical shape extending along the central axis (predetermined reference axis) L. That is, the cross-sectional shape of the first tubular portion 51 in the direction orthogonal to the central axis L is an annular shape. In the present embodiment, the length of the first tubular portion 51 along the central axis L is longer than the length of the second tubular portion 52 along the central axis L.

The second tubular portion 52 extends along the central axis L. The second cylinder portion 52 is arranged at the lower end portion of the first cylinder portion 51. That is, the second tubular portion 52 is on the upstream side in the traveling direction of the yarn Y unwound from the yarn feeding bobbin SB among both end portions (upper end portion and lower end portion) along the central axis L in the first cylinder portion 51. It is located at the end (lower end) of.

The second tubular portion 52 has a tapered shape whose diameter increases toward the lower end portion. That is, the second cylinder portion 52 has an end portion (lower end portion) opposite to the end portion (upper end portion) on the side connected to the first cylinder portion 51 to the end portion on the side connected to the first cylinder portion 51. It has a tapered shape that gradually expands toward the part). Further, the cross-sectional shape of the second tubular portion 52 in the direction orthogonal to the central axis L is an annular shape.

A low friction material layer 61 (low friction portion) having a coefficient of dynamic friction with respect to cotton yarn of 0.1 or more and less than 0.25 is provided on the inner peripheral surface of the guide cylinder 50. Here, the above-mentioned coefficient of dynamic friction is a measured value by the measuring method specified in "JIS L 1095: 2010 General Spinning Thread Test Method, Chapter 9.11, Coefficient of Friction". In the following description, the "coefficient of dynamic friction with respect to cotton thread" is simply referred to as "coefficient of dynamic friction". In the present embodiment, the cotton yarn is a yarn having an English cotton count of Ne30.

In the present embodiment, the low friction material layer 61 is provided on the entire inner peripheral surface 51a of the first tubular portion 51 and the inner peripheral surface 52a of the second tubular portion 52. The low friction material layer 61 can be formed, for example, by performing an electroless nickel PTFE composite plating treatment on the inner peripheral surface 51a and the inner peripheral surface 52a. Here, the coefficient of kinetic friction of the inner peripheral surface 51a and the inner peripheral surface 52a (that is, the pickled steel sheet soft-nitrided in the salt bath) is 0.25. That is, the frictional resistance of the inner peripheral surface of the guide cylinder 50 (in the present embodiment, the inner peripheral surface 51a and the inner peripheral surface 52a) is reduced as compared with the conventional material (salt bath soft-nitrided pickled steel plate). A low friction material layer 61 is provided.

In the thread unwinding assisting device 20 described above, the low friction material layer 61 is provided on the inner peripheral surface (inner peripheral surface 51a and inner peripheral surface 52a in the present embodiment) of the guide cylinder 50. Here, as a cause of the increase in the unwinding tension of the thread Y, the friction between the thread Y unwound from the thread feeding bobbin SB and the thread Y wound around the thread feeding bobbin SB (thread Y before unwinding). Can be considered. According to the guide cylinder 50, the low friction material layer 61 is used to check the slipperiness of the thread Y on the inner circumference of the guide cylinder 50 by pickling a conventional material (for example, a salt bath soft nitrided pickling having a dynamic friction coefficient of 0.25). It can be improved as compared with steel plate). As a result, the movement of the thread Y unwound from the thread feeding bobbin SB in the guide cylinder 50 can be promoted, and the thread Y unwound from the thread feeding bobbin SB and the thread Y wound around the thread feeding bobbin SB (unwinding). The frictional resistance generated between the thread Y) and the previous thread Y) can be reduced. As a result, the increase in unwinding tension can be effectively suppressed. As a result, it is possible to suppress the occurrence of thread breakage due to the increase in unwinding tension.

Further, the low friction material layer 61 is provided at least on the inner peripheral surface 51a of the first tubular portion 51. According to this configuration, the slipperiness of the thread Y can be appropriately improved in the first cylinder portion 51 which is a contact portion with the thread Y introduced into the guide cylinder 50 via the second cylinder portion 52. .. As a result, the movement of the thread Y unwound from the thread feeding bobbin SB in the guide cylinder 50 can be effectively promoted.

Further, the low friction material layer 61 is provided on both the inner peripheral surface 51a of the first tubular portion 51 and the inner peripheral surface 52a of the second tubular portion 52. According to this configuration, the slipperiness of the thread Y can be improved on the inner circumferences of both the first cylinder portion 51 and the second cylinder portion 52. As a result, the movement of the thread Y unwound from the thread feeding bobbin SB in the guide cylinder 50 can be promoted even more effectively.

Next, with respect to the yarn unwinding assisting device according to the embodiment and the yarn unwinding assisting device according to the comparative example, the measurement results of the guide tension of the yarn Y generated when the yarn Y is wound from the yarn feeding bobbin SB are shown. The guide tension is a tension value (cN) detected (measured) by the tension detecting device 24. The yarn unwinding assisting device according to the embodiment is a yarn unwinding assisting device 20 provided with a guide cylinder 50 having a low friction material layer 61 having a dynamic friction coefficient of 0.22. The yarn unwinding assisting device according to the comparative example has an inner peripheral surface 51a and an inner peripheral surface 52a having a dynamic friction coefficient of 0.25 in the entire inner circumference of the guide cylinder (that is, the entire inner circumference of the guide cylinder) in which the low friction material layer 61 is omitted. It is a thread unwinding assisting device equipped with a conventional structure in which is exposed. The measurement conditions are as follows.
・ Winding speed of thread Y: 2000m / min (constant)
-Type of thread Y: Cotton thread with English cotton count Ne30

FIG. 5 is a diagram showing the time change of the guide tension in the first half of unwinding (from the start of unwinding (0 seconds) to 25 seconds). FIG. 6 is a diagram showing the time change of the guide tension from the latter half of the unwinding (from before the unraveling is completed (0 seconds) to the time when the unwinding is completed (20 seconds)). As shown in FIGS. 5 and 6, in both the first half and the second half of the unwinding, according to the embodiment in which the guide cylinder 50 having the low friction material layer 61 provided on the inner peripheral surface is adopted, the conventional structure is used. It was confirmed that the guide tension can be suppressed more than in the comparative example adopted. Here, the guide tension is different from the tension applied to the yarn Y at the unwinding point of the yarn Y from the yarn feeding bobbin SB (unwinding tension), but there is a correlation between the guide tension and the unwinding tension. Therefore, from the above measurement results, it was confirmed that according to the examples, the increase in unwinding tension can be suppressed as compared with the comparative examples.

However, the present invention is not limited to the above embodiment. For example, the thread unwinding assisting device 20 may include the guide cylinder 50A shown in FIG. 7 instead of the guide cylinder 50 described above. The guide cylinder 50A is different from the guide cylinder 50 in that the above-mentioned low friction material layer 61 is provided on the inner peripheral surface 51a of the first cylinder portion 51, but is not provided on the inner peripheral surface 52a of the second cylinder portion 52. It is different. That is, in the guide cylinder 50A, the inner peripheral surface 52a of the second cylinder portion 52 is provided with a high friction portion having a dynamic friction coefficient larger than that of the low friction material layer 61. In the present embodiment, the inner peripheral surface 52a itself (the surface having a dynamic friction coefficient of 0.25) of the second tubular portion 52 functions as a high friction portion. According to this configuration, the high friction portion (inner peripheral surface 52a) suppresses the occurrence of sluffing according to the progress of unwinding of the yarn Y from the yarn feeding bobbin SB, and the low friction material layer 61 dissolves the yarn Y. It is possible to suppress an increase in the bobbin tension. Sluffing is a phenomenon in which the thread Y comes out of the thread feeding bobbin SB in an annular shape.

For example, in the first half of unwinding in which the amount of thread of the thread-feeding bobbin SB is large, the balloon of thread Y tends to be relatively large, and the influence of the balloon is dominant (the period in which sluffing is relatively likely to occur). The high friction portion (inner peripheral surface 52a) provided on the tubular portion 52 can effectively suppress the expansion of the balloon of the thread Y. On the other hand, for example, in the latter half of unwinding when the thread amount of the thread-feeding bobbin SB is reduced (for example, after the remaining unwinding amount becomes a three-quarter ball with 1/3), the balloon of thread Y is compared with the first half of unwinding. It is thought that the effect of the balloon will be limited because it is difficult to grow. Therefore, in the latter half of the unwinding, the friction between the thread Y unwound from the thread feeding bobbin SB and the thread Y wound around the thread feeding bobbin SB (the thread Y before unwinding) is the unwinding tension of the thread Y. It is thought that the degree of contribution to the increase will increase. According to the guide cylinder 50A, in the latter half of unwinding, the low friction material layer 61 provided on the first cylinder portion 51 causes the frictional resistance between the thread Y and the first cylinder portion 51 to be increased between the thread Y and the second cylinder portion 51. It can be less than the frictional resistance between 52 and 52. As a result, the movement of the thread Y unwound from the thread feeding bobbin SB in the first tubular portion 51 can be promoted, and the thread Y unwound from the thread feeding bobbin SB and the thread Y wound around the thread feeding bobbin SB The frictional resistance generated between the two can be reduced. As a result, it is possible to suppress an increase in unwinding tension.

As another modification, the thread unwinding assisting device 20 may include the guide cylinder 50B shown in FIG. 8 instead of the guide cylinder 50 described above. The guide cylinder 50B is provided with a high friction material layer 62 (high friction portion) having a dynamic friction coefficient of 0.3 or more and less than 0.5 on the inner peripheral surface 52a of the second cylinder portion 52. It is different from 50A. Specifically, in the guide cylinder 50B, the low friction material layer 61 is provided on the inner peripheral surface 51a of the first cylinder portion 51, while the high friction material layer 62 is provided on the inner peripheral surface 52a of the second cylinder portion 52. Is provided. The high friction material layer 62 can be formed of, for example, a rubber sheet or the like. According to the guide cylinder 50B, the slipperiness of the thread Y on the inner circumference of the second cylinder portion 52 is compared with that of a conventional material (for example, a salt bath soft-nitrided pickled steel sheet having a coefficient of dynamic friction of 0.25). Can be reduced. As a result, the expansion of the balloon of the thread Y in the first half of the unwinding described above can be suppressed more effectively. Specifically, since the frictional resistance between the thread Y and the second cylinder portion 52 in the first half of unwinding can be made larger than that of the guide cylinder 50A described above, the expansion of the balloon can be effectively suppressed by that amount. As a result, the occurrence of sluffing can be suppressed even more effectively.

At least a part of the above-described embodiments and various modifications may be arbitrarily combined. Further, the materials forming the guide cylinders 50, 50A, 50B, the low friction material layer 61, and the high friction material layer 62 are not limited to the above examples.

20 ... Thread unwinding assisting device, 50, 50A, 50B ... Guide cylinder, 51 ... First cylinder, 51a ... Inner peripheral surface, 52 ... Second cylinder, 52a ... Inner peripheral surface (high friction part), 61 ... Low friction material layer (low friction part), 62 ... High friction material layer (high friction part), L ... Central axis (reference axis), SB ... Thread feeding bobbin (bobbin), Y ... Thread.

Claims (5)

It is a thread unwinding assisting device that assists in unwinding the thread from the bobbin.
A guide tube is provided so as to cover the core tube of the bobbin.
A thread unwinding assisting device provided with a low friction portion having a coefficient of dynamic friction with respect to cotton yarn of 0.1 or more and less than 0.25 on the inner peripheral surface of the guide cylinder. The guide cylinder
A cylindrical first cylinder extending along a predetermined reference axis, and
A second end extending along the reference axis and being connected to an upstream end in the traveling direction of the thread unwound from the bobbin among both ends of the first cylinder along the reference axis. Has 2 bobbins and
The second tubular portion has a tapered shape that gradually expands from the end on the side connected to the first tubular portion toward the end opposite to the end on the side connected to the first tubular portion. Have,
The thread unwinding assisting device according to claim 1, wherein the low friction portion is provided at least on the inner peripheral surface of the first cylinder portion. The thread unwinding assisting device according to claim 2, wherein the low friction portion is provided on both the inner peripheral surface of the first cylinder portion and the inner peripheral surface of the second cylinder portion. The yarn unwinding assisting device according to claim 2, wherein a high friction portion having a coefficient of dynamic friction with respect to the cotton yarn larger than that of the low friction portion is provided on the inner peripheral surface of the second cylinder portion. The yarn unwinding assisting device according to any one of claims 1 to 4, wherein the cotton yarn is a yarn having an English cotton count of Ne30.

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