EP2865795A1

EP2865795A1 - Drafting device and spinning machine

Info

Publication number: EP2865795A1
Application number: EP20140188973
Authority: EP
Inventors: Harutoshi Sawada; Naritoshi Ota; Manabu Fujita
Original assignee: Murata Machinery Ltd
Current assignee: Murata Machinery Ltd
Priority date: 2013-10-23
Filing date: 2014-10-15
Publication date: 2015-04-29
Also published as: CN104562318A; JP2015081398A; CN104562318B

Abstract

A drafting device (6) drafts a sliver (S) to form a fiber bundle (F). The drafting device (6) includes plural roller pairs, a first regulating member (74) and a second regulating member (77). The roller pairs convey the sliver (S) from an upstream side to a downstream side while drafting the sliver (S). The first regulating member (74) and the second regulating member (77) separately regulate the width of the sliver (S). The roller pairs include a back roller pair (61) arranged on the extreme upstream side and a front roller pair (65) arranged on the extreme downstream side. The first regulating member (74) is arranged between the back roller pair (61) and the front roller pair (65). The second regulating member (77) is arranged between the first regulating member (74) and the front roller pair (65).

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a drafting device and a spinning machine.

2. Description of the Related Art

Drafting devices that include plural roller pairs that convey a fiber bundle (which can be a sliver) from an upstream side to a downstream side while drafting the fiber bundle, and a regulating member (also called a sliver guide or a condenser) that regulates a width of the fiber bundle between adjacent roller pairs are known in the art (for example, Japanese Patent Application Laid-open No. 2004-218105 ).
In such drafting devices, a distance between adjacent roller pairs needs to be adjusted in accordance with a fiber length of the fibers forming the fiber bundle. However, because a distance from the roller pair on the upstream side to the regulating member increases when the distance between adjacent roller pairs is increased, a width of the fiber bundle at the roller pair on the upstream side increases, leading to a reduction in the drafting resistance. The reduced drafting resistance can make the movement of the fibers uncontrollable and the fibers may unfavorably wind around the roller pair on the upstream side (the so-called wrapping-up phenomenon).

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a drafting device that is capable of preventing unfavorable winding of the fibers around the roller pair due to uncontrolled movement of the fibers caused by a reduced drafting resistance, and a spinning machine equipped with such a drafting device.
The drafting device according to an aspect of the present invention drafts a fiber bundle, and includes plural roller pairs that convey the fiber bundle from an upstream side to a downstream side while drafting the fiber bundle, the roller pairs include a first roller pair arranged at an extreme upstream side and a second roller pair arranged at an extreme downstream side, a first regulating member that is arranged between the first roller pair and the second roller pair and that regulates a width of the fiber bundle, and a second regulating member that is arranged between the first regulating member and the second roller pair and that regulates the width of the fiber bundle.
A spinning machine according to an aspect of the present invention includes the above drafting device, an air spinning device that twists the fiber bundle drafted by the drafting device to form a spun yarn, and a winding device that winds the spun yarn formed by the air spinning device into a package.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of a spinning machine according to an embodiment of the present invention;
FIG. 2 is a side view of a spinning unit of the spinning machine shown in FIG. 1;
FIG. 3 is a top view of a drafting device of the spinning unit shown in FIG. 2;
FIG. 4 is a side view of the drafting device of the spinning unit shown in FIG. 2; and
FIG. 5 is a cross-sectional view of a first supporting member and a second supporting member along a route over which a sliver is conveyed.

DETAILED DESCRIPTION

Exemplary embodiments of the present invention are explained in detail below with reference to the accompanying drawings. In the drawings, same reference symbols or numerals have been used to denote identical component parts or equivalent component parts and in the description, repeat descriptions have been omitted.
As shown in FIG. 1, a spinning machine 1 includes plural spinning units 2, a yarn joining carrier 3, a blower box 4, and a motor box 5. The spinning units 2 are arranged side-by-side. Each spinning unit 2 forms a spun yarn Y and winds the spun yarn Y to form a package P. The yarn joining carrier 3 performs a yarn joining operation in the spinning unit 2 where breakage of the spun yarn Y has occurred. The blower box 4 houses therein an air supplying source, etc., for generating a suction flow and swirling air current, etc., in each component part of the spinning units 2. The motor box 5 houses therein a motor, etc., for supplying power to each component part of the spinning units 2.
In the following explanation, on a route over which the spun yarn Y runs (that is, a yarn path), the term "upstream side" refers to the side where the spun yarn Y is formed and the term "downstream side" refers to the side where the spun yarn Y is wound. The term "front side" refers to the side relative to the yarn joining carrier 3 where the yarn path is present, and the term "back side" refers to the opposite side relative to the yarn joining carrier 3. A not shown working passage extending in an arrangement direction of the spinning units 2 is located on the front side of the spinning machine 1. An operator can operate and monitor the spinning units 2 from the working passage.
As shown in FIGS. 1 and 2, each spinning unit 2 includes, sequentially from the upstream side, a drafting device 6, an air spinning device 7, a yarn clearer 8, a tension sensor 9, a yarn pooling device 50, a waxing device 11, and a winding device 12. These devices are directly or indirectly supported by a machine frame 13 in such a manner that the upstream side is on top in a height direction of the spinning machine 1 (that is, the downstream side is at the bottom in the height direction of the spinning machine 1).
The drafting device 6 drafts a sliver (fiber bundle) S. The drafting device 6 includes, sequentially from the upstream side (along the route over which the sliver S is conveyed, on the side from where the sliver S is supplied) a back roller pair (first roller pair) 61, a third roller pair (fourth roller pair) 62, a middle roller pair (third roller pair) 64 with an apron belt 63 stretched thereon, and a front roller pair (second roller pair) 65.
The air spinning device 7 twists the fiber bundle F drafted by the drafting device 6 with a swirling air current to form the spun yarn Y. More specifically (though not shown), the air spinning device 7 includes a spinning chamber, a fiber guiding member, a swirling air current generating nozzle, and a hollow guide shaft member. The fiber guiding member guides the fiber bundle F supplied by the drafting device 6 into the spinning chamber. The swirling airflow generating nozzle is arranged near the route over which the fiber bundle F runs, and create a swirling airflow inside the spinning chamber. The swirling airflow causes the fiber end of the fiber bundle F guided into the spinning chamber to be reversed and swirled. The hollow guide shaft member guides the spun yarn Y from inside the spinning chamber to outside of the air spinning device 7.
The yarn clearer 8 monitors the running spun yarn Y at a position between the air spinning device 7 and the yarn pooling device 50. The yarn clearer 8, upon detecting any yarn defect, sends a yarn defect detection signal to a unit controller 10. For example, an abnormality in a thickness of the spun yarn Y and/or presence of foreign matter in the spun yarn Y, etc., is detected as a yarn defect by the yarn clearer 8. The tension sensor 9 measures a tension of the running spun yarn Y at a position between the air spinning device 7 and the yarn pooling device 50, and sends a tension measurement signal to the unit controller 10. The waxing device 11 applies wax on the running spun yarn Y at a position between the yarn pooling device 50 and the winding device 12. The unit controller 10 is arranged individually for each one of the spinning units 2 and controls the operations of the concerned spinning unit 2.
The yarn pooling device 50 pools the running spun yarn Y at a position between the air spinning device 7 and the winding device 12. The yarn pooling device 50 has functions of stably drawing the spun yarn Y from the air spinning device 7, pooling the spun yarn Y coming out from the air spinning device 7 to prevent slackening of the spun yarn Y during the yarn joining operation, etc., performed by the yarn joining carrier 3, and adjusting the tension of the spun yarn Y on the winding device 12 side to prevent any change in the tension of the spun yarn Y on the winding device 12 side from being conveyed to the air spinning device 7.
The winding device 12 winds the spun yarn Y formed by the air spinning device 7 onto a bobbin B to form the package P. The winding device 12 includes a cradle arm 21, a winding drum 22, and a traverse device 23. The cradle arm 21 is swingably supported by a shaft 24 and brings a surface of the rotatably supported bobbin B or the package P into contact with a surface of the winding drum 22 at an appropriate pressure. The winding drum 22 is driven by a not shown electric motor that is provided individually for each one of the spinning units 2 to rotate the bobbin B or the package P that is in contact with the winding drum 22. The traverse device 23 is driven by a shaft 25 that is common to the plural spinning units 2, and traverses the spun yarn Y by a predetermined width on the rotating bobbin B or package P.
The yarn joining carrier 3 moves to the spinning unit 2 where breakage of the spun yarn Y has occurred, and performs the yarn joining operation at the particular spinning unit 2. The yarn joining carrier 3 includes a splicer 26, a suction pipe 27, and a suction mouth 28. The suction pipe 27 is swingably supported by a shaft 31, and catches the end of the spun yarn Y from the air spinning device 7 by suction, and guides the caught yarn end to the splicer 26. The suction mouth 28 is swingably supported by a shaft 32, and catches the end of the spun yarn Y from the winding device 12 by suction, and guides the caught yarn end to the splicer 26. The splicer 26 joins the two yarn ends together.
The drafting device 6 is explained below in further detail. As shown in FIGS. 3 and 4, the back roller pair 61 includes a back bottom roller 61a and a back top roller 61b that are arranged opposite each other on either side of a route R over which the sliver S is conveyed (hereinafter, "route R"). The third roller pair 62 includes a third bottom roller 62a and a third top roller 62b that are arranged opposite each other on either side of the route R. The middle roller pair 64 includes a middle bottom roller 64a and a middle top roller 64b that are arranged opposite each other on either side of the route R. An apron belt 63a is stretched over the middle bottom roller 64a and an apron belt 63b is stretched over the middle top roller 64b. The front roller pair 65 includes a front bottom roller 65a and a front top roller 65b that are arranged opposite each other on either side of the route R. The roller pairs 61, 62, 64, and 65 convey the sliver S that is supplied via a truncated conical-shaped guiding member 83 from a not shown can, from an upstream side to a downstream side while drafting the sliver S.
The back bottom roller 61a is rotatably supported by a back roller housing 66. The third bottom roller 62a is rotatably supported by a third roller housing 67. The middle bottom roller 64a over which the apron belt 63a is stretched is rotatably supported by a middle roller housing 68. The front bottom roller 65a is rotatably supported by a front roller housing 69. Each one of the bottom rollers 61a, 62a, 64a, and 65a is rotated at a different rotational speed from the other bottom rollers 61a, 62a, 64a, and 65a by power from the motor box 5 such that the rotational speed of each roller is faster than the rotational speed of the adjacent roller on its upstream side.
Each one of the roller housings 66, 67, 68, and 69 is mounted on the machine frame 13. The positions of the back roller housing 66, the third roller housing 67, and the middle roller housing 68 are adjustable along the route R. This structure enables adjustment of a distance between the front bottom roller 65a and the middle bottom roller 64a, a distance between the middle bottom roller 64a and the third bottom roller 62a, and a distance between the third bottom roller 62a and the back bottom roller 61a.
The back top roller 61b, the third top roller 62b, the middle top roller 64b over which the apron belt 63b is stretched, and the front top roller 65b are rotatably supported by a draft cradle 71. The top rollers 61b, 62b, 64b, and 65b are brought into contact with the bottom rollers 61a, 62a, 64a, and 65a, respectively, at an appropriate pressure and driven to rotate. With this structure, each one of the top rollers 61b, 62b, 64b, and 65b is rotated at a different rotational speed from the other top rollers 61b, 62b, 64b, and 65b, such that the rotational speed of each roller is faster than the rotational speed of the adjacent roller on its upstream side.
The draft cradle 71 swingable about the shaft 72 between a position in which the top rollers 61b, 62b, 64b, and 65b are in contact with the bottom rollers 61a, 62a, 64a, and 65a, respectively, at an appropriate pressure, and a position in which the top rollers 61b, 62b, 64b, and 65b are separated from the bottom rollers 61a, 62a, 64a, and 65a, respectively. The pivoting of the draft cradle 71 is carried out by using a not shown handle provided on the draft cradle 71. The draft cradle 71 rotatably supports the top rollers 61b, 62b, 64b, and 65b of the drafting devices 6 of a pair of adjacent spinning units 2. That is, one draft cradle 71 is shared by the drafting devices 6 of two adjacent spinning units 2.
A side guide 73 is mounted on a side surface of the draft cradle 71. The side guide 73 regulates a distance between the front top roller 65b and the middle top roller 64b, a distance between the middle top roller 64b and the third top roller 62b, and a distance between the third top roller 62b and the back top roller 61b. Various types of the side guides 73 are prepared. A suitable one of the side guides 73 is used in accordance with the desired distances between the front bottom roller 65a and the middle bottom roller 64a, the middle bottom roller 64a and the third bottom roller 62a, and the third bottom roller 62a and the back bottom roller 61a.
A first regulating member 74 is arranged between the third roller pair 62 and the middle roller pair 64. The first regulating member 74 regulates a width of the sliver S in a direction in which the rotational axis of each one of the rollers 61a, 61b, 62a, 62b, 64a, 64b, 65a, and 65b extend (hereinafter, "rotational axis direction"). The first regulating member 74 is supported by a first supporting member 81. The first supporting member 81 is located below the route R in a height direction of the spinning machine 1 and is mounted on the third roller housing 67. With this structure, the third roller housing 67 functions as an adjusting member that adjusts the position of the third roller pair 62 relative to the middle roller pair 64 while maintaining the position of the first regulating member 74 relative to the third roller pair 62.
A second regulating member 77 is arranged between the first regulating member 74 and the middle roller pair 64. The second regulating member 77 regulates the width of the sliver S in the rotational axis direction. The second regulating member 77 is supported by a second supporting member 82. The second supporting member 82 is located below the route R in the height direction of the spinning machine 1 and is mounted on the middle roller housing 68. With this structure, the position of the second regulating member 77 relative to the middle roller pair 64 is maintained. The first regulating member 74 and the second regulating member 77 are not shown in FIGS. 1 and 2.
As shown in FIG. 5, a first through hole 75a having a rectangular cross-section with a gradually decreasing width in the rotational axis direction is formed in a body 75 of the first regulating member 74. The body 75 is an integrally molded member made of, for example, resin. The first through hole 75a is located on the route R and the sliver S can be passed through it. In the body 75, at an outlet of the first through hole 75a on the downstream side, a pair of regulating members 76 is arranged juxtaposed, at a first width W1, along the rotational axis direction. The regulating members 76 are rod-like members made of, for example, metal. With this structure, the first regulating member 74 regulates the width of the sliver S in the rotational axis direction to the first width W1.
A second through hole 78a having a rectangular cross-section with gradually decreasing width in the rotational axis direction is formed in a body 78 of the second regulating member 77. The body 78 is an integrally molded member made of, for example, resin. The second through hole 78a is located on the route R, and the sliver S can be pass through it. In the body 78, at an outlet of the second through hole 78a on the downstream side, a pair of regulating members 79 is arranged juxtaposed, at a second width W2 that is narrower than the first width W1, along the rotational axis direction. The regulating members 79 are rod-like members made of, for example, metal. With this structure, the second regulating member 77 regulates the width of the sliver S in the rotational axis direction to the second width W2 that is narrower than the first width W1.
The first supporting member 81 includes a fluff passage portion 81a. The first supporting member 81 is a plate-like member made of, for example, metal, and the fluff passage portion 81a is an opening provided in the plate-like member. By fitting the first supporting member 81 into a groove 75b provided in the body 75, the first regulating member 74 is mounted on the first supporting member 81 in a state of being positioned relative to the route R.
The second supporting member 82 includes a fluff passage portion 82a. The second supporting member 82 is a plate-like member made of, for example, metal, and the fluff passage portion 82a is an opening provided in the plate-like member. By fitting the second supporting member 82 into a groove 78b provided in the body 78, the second regulating member 77 is mounted on the second supporting member 82 in a state of being positioned relative to the route R.
As explained above, in the drafting device 6, the first regulating member 74 and the second regulating member 77 that regulate the width of the sliver S in the rotational axis direction are arranged between the third roller pair 62 and the middle roller pair 64. Because the second regulating member 77 regulates the width of the sliver S to be conveyed to the middle roller pair 64 and the front roller pair 65, the position of the second regulating member 77 relative to the middle roller pair 64 has a relatively significant effect on the physical properties of the fiber bundle F being formed. Consequently, physical properties of the fiber bundle F being formed can be maintained stable by maintaining a constant distance between the middle roller pair 64 and the second regulating member 77. With this structure, even if the distance between the third roller pair 62 and the second regulating member 77 is increased by increasing the distance between the third roller pair 62 and the middle roller pair 64 in accordance with the length of the fibers of the sliver S, the first regulating member 74 is always arranged between the third roller pair 62 and the second regulating member 77. This first regulating member 74 prevents unfavorable winding of the fibers around the third roller pair 62 due to uncontrolled movement of the fibers caused by reduced drafting resistance (the so-called wrapping-up phenomenon). In the spinning machine 1 equipped with the drafting device 6 having the above configuration, a high quality package P can be efficiently formed.
For example, when the length of the fibers in the sliver S is greater than or equal to two inches, there may be a case where it is desirable to set the distance between the third roller pair 62 and the middle roller pair 64 to 50 millimeters (mm) or more. If, in such a scenario, the first regulating member 74 is not provided, the possibility of the fibers wrapping up around the third roller pair 62 increases to a great extent. It is therefore particularly effective to arrange the first regulating member 74 and the second regulating member 77 between the third roller pair 62 and the middle roller pair 64 in such a case.
In the drafting device 6, the third roller housing 67 functions as an adjusting member that adjusts the position of the third roller pair 62 relative to the middle roller pair 64 while maintaining the position of the first regulating member 74 relative to the third roller pair 62. With this structure, the position of the first regulating member 74 relative to the third roller pair 62 is maintained even if adjustments are made to the position of the third roller pair 62 relative to the middle roller pair 64. Consequently, unfavorable winding of the fibers around the third roller pair 62 due to uncontrolled movement of the fibers caused by reduced drafting resistance can be prevented. Hence, no adjustments need to be made to the position of the first regulating member 74 relative to the third roller pair 62.
In the drafting device 6, the first regulating member 74 regulates the width of the sliver S to the first width W1 and the second regulating member 77 regulates the width of the sliver S to the second width W2 that is narrower than the first width W1. With this structure, the width of the sliver S being conveyed from the upstream side to the downstream side while being drafted can be smoothly regulated (that is, without applying extra load on the sliver S).
In the drafting device 6, the fluff passage portion 81a is provided in the first supporting member 81 that supports the first regulating member 74 and the fluff passage portion 82a is provided in the second supporting member 82 that supports the second regulating member 77. With this structure, accumulation of fluff on the first supporting member 81 and the second supporting member 82 that are located below the route R in the height direction of the spinning machine 1 can be suppressed.
In the drafting device 6, each one of the first supporting member 81 and the second supporting member 82 is a plate-like member and each one of the fluff passage portion 81a and the fluff passage portion 82a is an opening provided in the respective plate-like member. With this structure, the first supporting member 81 and the second supporting member 82 that suppress fluff accumulation can be realized with a simple structure.
An embodiment of the present invention has been explained above. However, the present invention is not limited to the above-explained embodiment. For example, the plural roller pairs can include only a first roller pair arranged on the extreme upstream side and a second roller pair arranged on the extreme downstream side. In this case, the first regulating member and the second regulating member can be arranged between the first roller pair and the second roller pair. The plural roller pairs can further include a third roller pair arranged on the upstream side of the second roller pair. In this case, the first regulating member and the second regulating member can be arranged between the first roller pair and the third roller pair. In these configurations also the fibers can be prevented from unfavorably winding around the roller pair due to uncontrolled movement of the fibers caused by reduced drafting resistance while stably maintaining the physical properties of the fiber bundle F being formed.
To prevent the twist of the fiber bundle from being conveyed to the upstream side of the air spinning device, the air spinning device can further include a needle that is held by the fiber guiding member and protruding into the spinning chamber. Instead of the needle, the air spinning device can use a downstream side end of the fiber guiding member to prevent the twist of the fiber bundle from being conveyed to the upstream side of the air spinning device. Alternatively, the air spinning device can include a pair of air jet nozzles that impart twist in opposite directions.
In the spinning machine 1, the yarn pooling device 50 has the function of drawing the spun yarn Y from the air spinning device 7. However, in the spinning machine according to the present invention, the spun yarn Y can be drawn by using a delivery roller and a nip roller.
In the spinning machine 1, the various devices are arranged such that the spun yarn Y supplied from the top is wound at the bottom. However, in a spinning machine according to an alternative configuration of the present invention, the various devices can be arranged such that the spun yarn Y supplied from the bottom is wound at the top.
In the spinning machine 1, the bottom rollers of the drafting device 6 and the traverse mechanism that is the traverse device 23 are driven by the power from one motor box 5 (that is common to the plural spinning units 2). In a spinning machine according to an alternative configuration of the present invention, the various component parts of the spinning unit 2 (for example, the drafting device, the spinning device, the winding device, etc.) can be driven independently for each spinning unit 2.
The tension sensor 9 can be arranged on the upstream side of the yarn clearer 8 in a running direction of the spun yarn Y. Instead of arranging one unit controller 10 individually for each spinning unit 2, one common unit controller 10 can be arranged for the plural spinning units 2. The waxing device 11, the tension sensor 9, and the yarn clearer 8 need not be arranged in the spinning unit 2. The winding device 12 can be driven by a driving source arranged commonly for the plural spinning units 2 instead of by one driving motor arranged individually for each spinning unit 2 of which the winding device 12 is a component part. In such a case, the cradle arm 21 is moved by a not shown air cylinder to cause the package P to separate from the winding drum 22, and the package P is reverse-rotated by a not shown roller for reverse rotation arranged in the yarn joining carrier 3.
The drafting device according to an aspect of the present invention drafts a fiber bundle, and includes plural roller pairs that convey the fiber bundle from an upstream side to a downstream side while drafting the fiber bundle, the roller pairs include a first roller pair arranged at an extreme upstream side and a second roller pair arranged at an extreme downstream side, a first regulating member that is arranged between the first roller pair and the second roller pair and that regulates a width of the fiber bundle, and a second regulating member that is arranged between the first regulating member and the second roller pair and that regulates the width of the fiber bundle.
With this structure, even if the distance between the adjacent roller pairs is increased in accordance with the length of the fibers of the fiber bundle, unlike the case in which only one regulating member is arranged, increase in a distance from the roller pair on the upstream side to the regulating member can be prevented. Hence, in the drafting device according to the present invention, unfavorable winding of the fibers around the roller pair due to uncontrolled movement of the fibers caused by reduced drafting resistance can be prevented.
In the drafting device according another aspect of the present invention, the roller pairs can further include a third roller pair arranged on the upstream side of the second roller pair, and the first regulating member and the second regulating member can be arranged between the first roller pair and the third roller pair. Because the second regulating member regulates the width of the fiber bundle being conveyed by the second roller pair and the third roller pair, a position of the second regulating member relative to the third roller pair has a relatively significant effect on the physical properties of the fiber bundle being formed. Consequently, stable physical properties of the fiber bundle being formed can be maintained by maintaining a constant distance between the third roller pair and the second regulating member. With this structure, even if the distance between the roller pair on the upstream side (the roller pair located on the upstream side of the second roller pair and the third roller pair) and the second regulating member increases, the first regulating member prevents unfavorable winding of the fibers around the roller pair on the upstream side (the roller pair located on the upstream side of the second roller pair and the third roller pair) due to uncontrolled movement of the fibers caused by reduced drafting resistance.
In the drafting device according to still another aspect of the present invention, the roller pairs can further include a fourth roller pair arranged on the upstream side of the third roller pair, and the first regulating member and the second regulating member can be arranged between the fourth roller pair and the third roller pair. With this structure, a constant distance can be maintained between the third roller pair and the second regulating member, and physical properties of the fiber bundle being formed can be maintained stable. With this structure, even if the distance between the fourth roller pair and the second regulating member increases, the first regulating member prevents unfavorable winding of the fibers around the roller pair on the upstream side (the roller pair located on the upstream side of the second roller pair and the third roller pair) due to uncontrolled movement of the fibers caused by reduced drafting resistance.
The drafting device according to still another aspect of the present invention can further include an adjusting member that adjusts a position of the fourth roller pair relative to the third roller pair while maintaining a position of the first regulating member relative to the fourth roller pair. With this structure, the position of the first regulating member relative to the fourth roller pair is maintained even if adjustments are made to the position of the fourth roller pair relative to the third roller pair. Consequently, unfavorable winding of the fibers around the fourth roller pair due to uncontrolled movement of the fibers caused by reduced drafting resistance can be prevented. Hence, no adjustments need to be made to the position of the first regulating member relative to the fourth roller pair.
In the drafting device according to still another aspect of the present invention, the first regulating member and the second regulating member can regulate a width of the fiber bundle in an extending direction of rotational axes of the rollers forming the plurality of the roller pairs. With this structure, unfavorable winding of the fibers around the roller pair due to uncontrolled movement of the fibers caused by reduced drafting resistance can be more properly prevented.
In the drafting device according to still another aspect of the present invention, the first regulating member can regulate the width of the fiber bundle to a first width and the second regulating member can regulate the width of the fiber bundle to a second width that is narrower than the first width. With this structure, the width of the fiber bundle that is conveyed from the upstream side to the downstream side while being drafted can be smoothly regulated (that is, without applying extra load on the fiber bundle).
The drafting device according to still another aspect of the present invention further includes a first supporting member that supports the first regulating member and a second supporting member that supports the second regulating member, wherein a fluff passage portion can be formed in each one of the first supporting member and the second supporting member. With this structure, accumulation of fluff on the first supporting member and the second supporting member can be suppressed.
In the drafting device according to still another aspect of the present invention, each one of the first supporting member and the second supporting member can be a plate-like member, and the fluff passage portion can be an opening provided in the plate-like member. With this structure, the first supporting member and the second supporting member that suppress fluff accumulation can be realized with a simple configuration.
A spinning machine according to still another aspect of the present invention includes the above drafting device, an air spinning device that twists the fiber bundle drafted by the drafting device to form a spun yarn, and a winding device that winds the spun yarn formed by the air spinning device into a package.
Since the spinning machine includes the above drafting device, a high-quality package can be formed efficiently.

Claims

A drafting device (6) adapted to draft a fiber bundle (S), comprising:
plural roller pairs adapted to convey the fiber bundle (S) from an upstream side to a downstream side while drafting the fiber bundle (S), the roller pairs including a first roller pair (61) arranged on an extreme upstream side and a second roller pair (65) arranged on an extreme downstream side;

a first regulating member (74) arranged between the first roller pair (61) and the second roller pair (65) and adapted to regulate a width of the fiber bundle (S); and

a second regulating member (77) arranged between the first regulating member (74) and the second roller pair (65) and adapted to regulate the width of the fiber bundle (S).
The drafting device (6) as claimed in Claim 1, wherein
the roller pairs further includes a third roller pair (64) arranged upstream of the second roller pair (65), and
the first regulating member (74) and the second regulating member (77) are arranged between the first roller pair (61) and the third roller pair (64).
The drafting device (6) as claimed in Claim 2, wherein
the roller pairs further includes a fourth roller pair (62) arranged upstream of the third roller pair (64), and
the first regulating member (74) and the second regulating member (77) are arranged between the third roller pair (64) and the fourth roller pair (62).
The drafting device (6) as claimed in Claim 3, further comprising an adjusting member (67) adapted to adjust a position of the fourth roller pair (62) relative to the third roller pair (64) while maintaining a position of the first regulating member (74) relative to the fourth roller pair (62).
The drafting device (6) as claimed in any one of Claims 1 to 4, wherein each one of the first regulating member (74) and the second regulating member (77) is adapted to regulate the width of the fiber bundle (S) in an extending direction of rotational axes of rollers in the roller pairs (61, 62, 64, 65).
The drafting device (6) as claimed in Claim 5, wherein
the first regulating member (74) is adapted to regulate the width of the fiber bundle (S) to a first width (W1), and
the second regulating member (77) is adapted to regulate the width of the fiber bundle (S) to a second width (W2) that is narrower than the first width (W1).
The drafting device (6) as claimed in any one of Claims 1 to 6, wherein
a first through hole (75a) having a rectangular cross-section with a gradually decreasing width in a rotational axis direction of the rollers forming the roller pairs (61, 62, 64, 65) is formed in a body (75) of the first regulating member (74), and
a second through hole (78a) having a rectangular cross-section with a gradually decreasing width in the rotational axis direction of the rollers forming the roller pairs (61, 62, 64, 65) is formed in a body (78) of the second regulating member (77).
The drafting device (6) as claimed in any one of Claims 1 to 7, further comprising:
a first supporting member (81) adapted to support the first regulating member (74); and

a second supporting member (82) adapted to support the second regulating member (77),

wherein a fluff passage portion (81a, 82a) is formed in each one of the first supporting member (81) and the second supporting member (82).
The drafting device (6) as claimed in Claim 8, wherein
each one of the first supporting member (81) and the second supporting member (82) is a plate-like member, and
the fluff passage portion (81a, 82a) is an opening in the plate-like member.
A spinning machine (1) comprising:
the drafting device (6) as claimed in any one of Claims 1 to 9 ;

an air spinning device (7) adapted to form a spun yarn (Y) by twisting the fiber bundle (F, S) drafted by the drafting device (6); and

a winding device (12) adapted to wind the spun yarn (Y) formed by the air spinning device (7) into a package (P).