CN112501728B - Spinning unit and method for manufacturing spun yarn - Google Patents

Abstract

The invention provides a spinning unit and a method for manufacturing spun yarn. The spinning unit is provided with a drafting device and an air spinning device (9). A nozzle block (33) provided in an air spinning device (9) is provided with a spinning nozzle (37) and an inner wall surface (35) forming a cylindrical swirl chamber (34). The whole of the inner wall surface (35) is disposed in parallel with respect to the axis center. The 1 st distance (L1) which is the distance from the nip point of the front roller pair (25) to the upstream end of the hollow guide shaft body (40) in the fiber traveling direction is equal to or less than the perimeter of the swirl chamber (34). When viewed from the axis center, the nozzle center line (102) of the spinning nozzle (37) is tangent to the inner wall surface (35) or tangent to the inner wall surface (35) by parallel movement of the spinning nozzle (37) to the axis center side or less. The diameter (d) of the swirl chamber (34) at the location where the ejection port (37 a) of the spinning nozzle (37) is formed is 6.7mm or more and less than 9.0mm.

Description

Spinning unit and method for manufacturing spun yarn

Technical Field

The present invention relates generally to a spinning unit for spinning with air.

Background

The spinning unit for spinning with air includes a drafting device and an air spinning device. The drafting device lengthens the fiber bundle by using a roller pair. The air spinning device is provided with a nozzle block and a hollow guide shaft body. The nozzle block is formed with a spinning nozzle. The swirling air flow is generated by ejecting compressed air from the spinning nozzle. By this swirling air flow, the end portions of the fibers of the fiber bundle are reversed around the hollow guide shaft body and swirled. The reversed fibers are wound around the core fibers. The fiber bundle passes through a passage in the hollow guide shaft body, advances downstream, and is transported downstream as a spun yarn. Such spinning methods are disclosed in patent documents 1 to 3.

Japanese patent application laid-open No. 2003-193338 (patent document 1) describes that a through hole for inserting a hollow guide shaft is formed in a nozzle block. Patent document 1 describes that the inner diameter of the cylindrical space portion on the most upstream side of the through hole is set to 4mm to 6mm.

JP-A-3-241019 (patent document 2) discloses that the distance (1 st distance) from the entrance of a spindle (hollow guide shaft) to the front roller is 16.5mm, 20.5mm, or 24.5mm. Patent document 2 describes that the diameter of the nozzle block is 7mm. The nozzle block of patent document 2 is a member provided only at a portion upstream of the spindle. The spindle described in patent document 2 is rotatably mounted about an axis.

Japanese patent application laid-open No. 2009-1934 (patent document 3) describes that a wound fiber, which is reversed by a swirling air flow, makes one revolution along the inner portion Zhou Bida of the nozzle block.

In the conventional spinning method, a strong tension is sometimes applied to the wound fiber according to the generation position of the whirling airflow, the strength thereof, and the like, and the wound fiber is sometimes wound around the core fiber locally with a strong force. In the conventional spinning method, the winding fiber supplied into the spinning chamber may be overlapped with the winding fiber supplied next, and thus the winding fiber may be partially wound around the core fiber with a strong force. The spun yarn is partially wound with a strong force by winding the fiber, and thus has a hard feel. Further, since the entangled fiber and the core fiber are present on the surface of the spun yarn separately and the reflection form of light of the entangled fiber and the core fiber is different, the spun yarn becomes uneven in appearance. The conditions shown in patent documents 1 to 3 are not sufficient to uniformly wind the winding fiber around the core fiber.

Disclosure of Invention

The main object of the present invention is to provide a spinning unit capable of producing a spun yarn having soft hand feeling and uniform appearance.

According to the 1 st aspect of the present invention, there is provided a spinning unit of the following structure. That is, the spinning unit includes a draft device and an air spinning device. The draft device includes a front roller pair for nipping and feeding out the fiber bundle, and draft the fiber bundle. The air spinning device causes a swirling air flow to act on the fiber bundle sent out by the draft device to generate a spun yarn. The air spinning device includes a nozzle block and a hollow guide shaft. The nozzle block is formed with a spinning nozzle for ejecting air and an inner wall surface of a swirl chamber formed in a cylindrical shape, and a swirl air flow is generated in the swirl chamber by the air ejected from the spinning nozzle. The hollow guide shaft is configured to pass the fiber bundle passing through the swirl chamber, and is mounted so that rotation about a shaft center of the air spinning device as a rotation center is restricted during spinning. The whole inner wall surface is disposed in parallel with respect to the axis center. The 1 st distance from the nip point of the front roller pair to the upstream end of the hollow guide shaft body in the fiber traveling direction is equal to or less than the perimeter of the swirl chamber. When viewed from the axis center, the nozzle center line of the spinning nozzle is tangent to the inner wall surface, or the nozzle center line of the spinning nozzle is parallel-moved radially outward to be equal to or smaller than the radius of the spinning nozzle, so as to be tangent to the inner wall surface. The diameter of the swirl chamber at the position where the spinning nozzle is formed is 6.7mm or more and less than 9.0mm.

Since the nozzle center line and the inner wall surface have the above-described relationship and the inner wall surface of the swirl chamber is disposed in parallel with respect to the axis center, the swirling air flow along the inner wall surface can be caused to act on the entangled fibers. Accordingly, the winding fiber swirls along the inner wall surface, and thus, compared with a case where the winding fiber swirls around the outer surface of the hollow guide shaft body, the tension applied to the winding fiber can be reduced while dispersing the winding fiber. Further, since the 1 st distance is equal to or less than the circumference of the swirl chamber, the wound fiber is difficult to swirl one round in the swirl chamber, and thus is difficult to overlap with the wound fiber supplied next. In this regard, the entangled fibers are also easily dispersed. When considering the general 1 st distance, the diameter of the swirl chamber is more preferably in the above range (6.7 mm or more and less than 9.0 mm). The winding fiber is easily uniformly wound around the core fiber by the winding fiber dispersion or tension reduction. As a result, a spun yarn having a soft touch and a uniform appearance can be produced.

In the spinning unit, it is preferable that an angle between the axis center and the inner wall surface or an imaginary extension line of the axis center and the inner wall surface is 1.5 ° or less in a cross section taken by an arbitrary plane parallel to the axis center.

Thus, the parallelism between the axis center and the inner wall surface is sufficiently high, so that a swirling air flow with less turbulence along the inner wall surface can be generated.

The spinning unit is preferably configured as follows. That is, the diameter of the swirl chamber is d. The angle formed by a plane perpendicular to the axial center and the nozzle center line when viewed in the radial direction of the swirl chamber, that is, the nozzle angle is defined as θ. The length from the ejection port to the downstream end of the swirl chamber in the fiber traveling direction along the axial center is defined as h. In this case, dpi/2tanθ.ltoreq.h.ltoreq.dpi/tanθ holds.

Thus, the swirling air flow flowing along the nozzle angle swirls for half a revolution to one revolution in the swirling chamber, and therefore the entangled fiber can be swirled in an appropriate range.

The spinning unit is preferably configured as follows. That is, the air spinning device includes a fiber guiding member for guiding the fiber bundle sent out by the draft device toward the whirling chamber. The 2 nd distance is 0.3mm or more and 7.0mm or less, wherein the 2 nd distance is a component of a distance from a downstream end in a fiber traveling direction of the fiber guiding member to an upstream end in the fiber traveling direction of the hollow guiding shaft body in a direction parallel to an axial center of the hollow guiding shaft body.

This reduces the amount of fibers that are detached while reducing the tension applied to the wound fibers.

In the spinning unit, the number of the spinning nozzles formed in the nozzle block is preferably 3 to 6.

By forming the plurality of spinning nozzles in this way, the air ejected from the ejection port collides with the air ejected from the other ejection port, and thereby a swirling air flow can be generated also at a position upstream of the ejection port in the fiber traveling direction. Therefore, the swirling air flow along the inner wall surface can be generated in a wide range of the swirling chamber. In addition, by not excessively increasing the number of spinning nozzles, turbulence of the swirling air flow can be reduced.

In the spinning unit, the 1 st distance is preferably 19mm to 28 mm.

This makes it possible for the spinning unit to cope with spinning under various conditions.

According to the 2 nd aspect of the present invention, there is provided the following method for producing a spun yarn. That is, the method for producing the spun yarn includes a drawing step and a spinning step. In the drawing step, the fiber bundle is drawn by a drawing device including a front roller pair for nipping and feeding the fiber bundle. In the spinning step, spun yarn is produced by an air spinning device that causes a whirling airflow to act on the fiber bundle fed out by the draft device. The air spinning device includes a nozzle block and a hollow guide shaft. The nozzle block is formed with a spinning nozzle for ejecting air and an inner wall surface of a swirl chamber formed in a cylindrical shape, and a swirl air flow is generated in the swirl chamber by the air ejected from the spinning nozzle. The hollow guide shaft is configured to pass the fiber bundle passing through the swirl chamber, and is mounted so that rotation about a shaft center of the air spinning device as a rotation center is restricted during spinning. The inner wall surface is disposed in parallel with respect to the axis center. The 1 st distance from the nip point of the front roller pair to the upstream end of the hollow guide shaft body in the fiber traveling direction is equal to or less than the perimeter of the swirl chamber. When viewed from the axis center, the nozzle center line of the spinning nozzle is tangent to the inner wall surface, or the nozzle center line of the spinning nozzle is parallel-moved radially outward to be equal to or smaller than the radius of the spinning nozzle, so as to be tangent to the inner wall surface. The diameter of the swirl chamber at the position where the spinning nozzle is formed is 6.7mm or more and less than 9.0mm.

This can produce a spun yarn having a soft touch and a uniform appearance.

Drawings

Fig. 1 is a front view showing an overall structure of a spinning machine including a spinning unit according to an embodiment of the present invention.

Fig. 2 is a side view of the spinning unit.

Fig. 3 is a sectional view showing the structure of the air spinning device.

Fig. 4 is a schematic view of a spun yarn produced by a conventional spinning method.

Fig. 5 is a cross-sectional view (top cross-sectional view) of the air spinning device as seen in the axial direction.

Fig. 6 is a cross-sectional view showing the dimensions and angles of the respective parts of the draft device and the air spinning device.

Fig. 7 is a schematic view of a spun yarn produced by the spinning method according to the present embodiment.

Detailed Description

Next, a spinning machine 1 including a spinning unit 2 according to an embodiment of the present invention will be described with reference to the drawings. The spinning machine 1 shown in fig. 1 includes a plurality of spinning units 2, a yarn receiving carriage 3, a prime mover 4, and a machine control device 90, which are arranged in parallel.

The machine control device 90 is a device for centrally controlling the respective components of the spinning machine 1, and includes a monitor 91 and an input key 92. By performing an appropriate operation by the operator using the input key 92, it is possible to set the specific spinning unit 2 or all the spinning units 2, display the setting and state of the specific spinning unit 2 or all the spinning units 2 on the monitor 91, or the like.

As shown in fig. 2, each spinning unit 2 includes a draft device 7, an air spinning device 9, a yarn accumulating device 14, and a winding device 96, which are disposed in this order from the upstream side toward the downstream side. In the present specification, "upstream" and "downstream" refer to upstream and downstream in the traveling (passing) direction of the fiber bundle 8 and the spun yarn 10 at the time of spinning or in the flow direction of the compressed air to be sent out. Each spinning unit 2 spins the fiber bundle 8 fed from the draft device 7 by the air spinning device 9 to generate a spun yarn 10, and winds the spun yarn 10 by the winding device 96 to form a package 28.

The draft device 7 is provided near the upper end of the housing 5 of the spinning machine 1. The draft device 7 includes four pairs of rear roller pairs 21, third roller pairs 22, middle roller pairs 24 on which a belt 23 is stretched, and front roller pairs 25 in this order from the upstream side. The draft device 7 drafts the fiber bundle 8 (sliver) supplied from a not-shown can through the sliver guide 20 to a predetermined thickness (stretches the fiber bundle 8). Specifically, the draft device 7 rotates the roller pairs with the fiber bundle 8 sandwiched between the roller pairs. The fiber bundle 8 drawn by the drawing device 7 is supplied to the air spinning device 9. Hereinafter, the portion of the front roller pair 25 that grips the fiber bundle 8 will be referred to as a grip point.

The air spinning device 9 generates a spun yarn 10 using the fiber bundle 8 supplied from the draft device 7. Specifically, as shown in fig. 3, the air spinning device 9 includes a fiber guide member 31, a needle member 32, a nozzle block 33, and a hollow guide shaft body 40.

The fiber guide member 31 guides the fiber bundle 8 drawn by the drawing device 7 into the air spinning device 9. The needle member 32 is attached to the fiber guide member 31. The fiber bundle 8 drawn by the drawing device 7 is guided into the fiber guiding member 31, and wound around the needle member 32 to be guided. A 1 st plane 31a is formed at the downstream end of the fiber guide member 31. The 1 st plane 31a is formed with a planar opening for disposing the needle member 32 or passing the fiber bundle 8.

A nozzle block 33 is disposed downstream of the fiber guide member 31. The nozzle block 33 has a hollow portion through which the fiber bundle 8 passes. Specifically, a swirl chamber 34, which is a cylindrical space, is formed in the nozzle block 33. The nozzle block 33 has an inner wall surface 35 which is a curved surface along the circumferential direction of the swirl chamber 34. The 1 st plane 31a of the fiber guide member 31 forms the upstream end of the swirl chamber 34.

The axis center of the swirl chamber 34 coincides with the axis center of the hollow guide shaft body 40. Hereinafter, these axial centers (i.e., the axial center of the air spinning device 9) may be simply referred to as axial centers. In the present embodiment, the axial center of the swirl chamber 34 coincides with the axial center of the fiber guide member 31. The axial center of the swirl chamber 34 also coincides with the axial center of the needle member 32.

A spinning nozzle 37 is formed in the nozzle block 33. The spinning nozzle 37 is formed such that the air discharge side discharge port 37a faces the swirl chamber 34. The air spinning device 9 ejects compressed air from the spinning nozzle 37 into the whirling chamber 34, and causes the whirling airflow to act on the fiber bundle 8 in the whirling chamber 34.

The fiber bundle 8 is made up of a plurality of fibers. Some of the fibers included in the fiber bundle 8 are continuous between the nip point of the front roller pair 25 and the hollow guide shaft body 40. The fiber in this state is referred to as a core fiber 8a. The other part of the fibers included in the fiber bundle 8 is not continuous between the nip point of the front roller pair 25 and the hollow guide shaft body 40. In other words, the other portion is disposed such that the upstream end is located downstream of the nip point of the front roller pair 25 and the downstream end is located inside the hollow guide shaft body 40. The downstream end of such fibers is twisted into the core fiber 8a, but the upstream end is the free end. The free ends of the fibers introduced into the air spinning device 9 are swirled and flow downstream by a swirling air flow generated by compressed air discharged from the spinning nozzle 37. In this way, the free ends (upstream ends) of the fibers flow downstream, and the direction of the free ends is "reversed" to be directed downstream (lower side in fig. 3). Since the reversed fiber is entangled with the core fiber 8a as will be described later, the reversed fiber is referred to as entangled fiber 8b. Since the fiber bundle 8 is gradually moved downstream while being spun, one fiber is the core fiber 8a at the time point of being nipped by the front roller pair 25, and is changed to the wound fiber 8b at the time point of being released from the nip.

The free end of the wound fiber 8b is subjected to a swirling air flow flowing spirally around the hollow guide shaft body 40 in the swirling chamber 34. Thereby, the wound fiber 8b swirls around the outer surface (tapered surface) of the hollow guide shaft body 40. Thereby, the winding fiber 8b is gradually wound around the core fiber 8 a.

The core fiber 8a is led by the convoluted winding fiber 8b to be twisted. In this way, the winding fiber 8b is wound around the core fiber 8a, and the winding fiber 8b is twisted into the core fiber 8a by further twisting the core fiber 8a, thereby producing the spun yarn 10.

The twist of the core fiber 8a is desirably propagated to the upstream side (front roller pair 25 side), but the propagation is prevented by the needle member 32. In this way, the needle member 32 functions as a twist propagation prevention mechanism.

The nozzle block 33 has a tapered surface 38 formed so as to connect to the downstream end of the inner wall surface 35. The tapered surface 38 is a surface having a diameter that increases as it approaches the downstream side. By forming the tapered surface 38, the gap between the nozzle block 33 and the hollow guide shaft body 40 can be ensured. Thereby, the compressed air supplied to the swirl chamber 34 can be discharged.

The hollow guide shaft body 40 is a hollow member, and a 2 nd passage 40a is formed therein. The hollow guide shaft body 40 is disposed so as to face the fiber guide member 31. The hollow guide shaft body 40 is attached to the attachment portion 41 so that rotation about the shaft center is restricted (prevented) during spinning. The mounting portion 41 is configured to press the outer surface of the hollow guide shaft body 40 radially inward or to interfere with a part of the hollow guide shaft body 40 so that the hollow guide shaft body 40 cannot rotate even if a force in the rotational direction is applied to the hollow guide shaft body 40. When the hollow guide shaft 40 is of such a non-rotating type, it may be difficult to twist the fiber bundle 8 as compared with the rotating type described in patent document 2. Therefore, the air spinning device 9 is preferably configured to be capable of sufficiently twisting the fiber bundle 8. The twisted fiber bundle 8 is guided downstream by the 2 nd passage 40a, and is sent out as a spun yarn 10 from a yarn outlet (not shown) to the outside of the air spinning device 9.

A yarn quality measuring device 12 and a spinning sensor (spinning sensor) 13 are provided downstream of the air spinning device 9. The spun yarn 10 spun by the air spinning device 9 passes through the yarn quality measuring device 12 and the spinning sensor 13.

The yarn quality measuring device 12 monitors the thickness of the advancing spun yarn 10 by an optical sensor, not shown. When detecting a yarn defect of the spun yarn 10 (a portion having an abnormality such as the thickness of the spun yarn 10), the yarn quality measuring device 12 transmits a yarn defect detection signal to a not-shown unit controller. The yarn quality measuring device 12 is not limited to an optical sensor, and may be configured to monitor the thickness of the spun yarn 10 by using a capacitance sensor, for example. The yarn quality measuring device 12 may detect a foreign matter contained in the spun yarn 10 as a yarn defect.

The spinning sensor 13 is disposed immediately downstream of the yarn quality measuring device 12. The spinning sensor 13 can detect the tension of the spun yarn 10 between the air spinning device 9 and the yarn accumulating device 14. The spinning sensor 13 transmits a detection signal of the detected tension to the unit controller. The unit controller monitors the tension detected by the spinning sensor 13 to detect an abnormal portion such as a weak twist yarn. The spinning unit 2 may not be provided with the spinning sensor 13.

A yarn accumulating device 14 is provided downstream of the yarn quality measuring device 12 and the spinning sensor 13. As shown in fig. 2, the yarn accumulating device 14 includes a yarn accumulating roller 15 and a motor 16 for rotationally driving the yarn accumulating roller 15.

The yarn accumulating roller 15 is capable of temporarily accumulating a predetermined amount of spun yarn 10 while being wound around its outer peripheral surface. By rotating the yarn accumulating roller 15 at a predetermined rotational speed in a state in which the spun yarn 10 is wound around the outer peripheral surface of the yarn accumulating roller 15, the spun yarn 10 can be drawn out from the air spinning device 9 at a predetermined speed and conveyed to the downstream side. Further, since the spun yarn 10 can be temporarily accumulated on the outer peripheral surface of the yarn accumulating roller 15, the yarn accumulating device 14 can be made to function as a kind of buffer. This can eliminate a problem (for example, loosening of the spun yarn 10) in which the spinning speed and the winding speed (the speed of the spun yarn 10 wound into the package 28) of the air-spinning device 9 are not uniform for some reason.

The winding device 96 includes a rocker arm 97, a winding drum 98, a traverse guide 99, and a winding drum drive motor, not shown. The rocker arm 97 rotatably supports a bobbin around which the spun yarn 10 is wound. The winding drum 98 rotates in contact with the outer peripheral surface of the bobbin or the package 28 by being transmitted with the driving force of the winding drum driving motor. The traverse guide 99 is capable of guiding the spun yarn 10. The winding device 96 reciprocates the traverse guide 99 by a driving mechanism, not shown, and drives the winding drum 98 by a winding drum driving motor. Thereby, the winding device 96 rotates the package 28 in contact with the winding drum 98, and winds the spun yarn 10 around the package 28 while traversing the spun yarn 10.

As shown in fig. 1 and 2, the yarn joining carriage 3 includes a yarn joining device 93, a suction pipe 94, and a suction nozzle 95. When a yarn break or yarn cutting occurs in a certain spinning unit 2, the yarn joining carriage 3 travels on a rail, not shown, to the spinning unit 2 and stops. The suction pipe 94 rotates upward about an axis to catch the spun yarn 10 fed from the air spinning device 9, and rotates downward about the axis to guide the spun yarn 10 to the yarn joining device 93. The suction nozzle 95 rotates downward about the axis, catches the spun yarn 10 from the package 28, and guides the spun yarn 10 to the yarn receiving device 93 by rotating upward about the axis. The yarn joining device 93 joins the guided spun yarns 10 to each other.

Next, a conventional spun yarn and its problems will be described with reference to fig. 4. In the spinning using the conventional air spinning device, a strong swirl flow may be locally generated mainly around the outer surface of the hollow guide shaft (especially, in the vicinity of the upstream end). As a result, the winding fiber 8b may be concentrated in the vicinity of the outer surface of the hollow guide shaft, and the winding fiber 8b may be partially wound around the core fiber 8a with a strong force (fig. 4). The partial winding means that the portion around which the wound fiber 8b is wound is clearly distinguished from the portion around which the wound fiber 8b is not wound in the longitudinal direction of the spun yarn 10. In addition, even when the wound fiber 8b is wound so as to follow the inner wall surface of the winding chamber, the wound fiber 8b may overlap with the wound fiber 8b to be supplied next and may be wound together. As a result, the entangled fibers 8b are hardly dispersed, so that the entangled fibers 8b are locally entangled with the core fibers 8a with a strong force.

The spun yarn 10 is partially wound with a strong force around the fiber 8b, and thus has a hard feel. In addition, the winding fiber 8b exists on the surface of the spun yarn 10 separately from the core fiber 8 a. In the wound fiber 8b and the core fiber 8a, the reflection form of light is different due to the different directions of the fibers. As a result, the appearance of the spun yarn 10 becomes uneven.

Next, the detailed shape of the air spinning device 9, the positional relationship between the air spinning device 9 and the draft device 7, and the like will be described mainly with reference to fig. 5 and 6. In the following description, terms that indicate angles such as parallel or perpendicular include not only strictly parallel and the like but also substantially parallel and the like. The range of the substantially parallel or the like is, for example, an error of ±3° or ±5°. The terms circular, straight, tangential, or overall include not only strictly circular, but also substantially circular.

The air spinning device 9 of the present embodiment has mainly two features as compared with the conventional air spinning device. The 1 st feature is that a swirling air flow along the inner wall surface 35 of the swirling chamber 34 can be generated, and the swirling air flow can be generated also at a position upstream of the ejection port 37a in the fiber traveling direction. Feature 2 is that the wound fiber 8b does not overlap with the wound fiber 8b supplied next.

First, the structure of the air spinning device 9 for exhibiting the 1 st feature will be described.

As shown in fig. 5, four spinning nozzles 37 are formed in the nozzle block 33. The spinning nozzles 37 are formed at intervals of 90 ° with respect to the shaft center (i.e., formed in such a manner that the angles between the spinning nozzles 37 are equal).

In order to generate a swirling air flow along the inner wall surface 35, the spinning nozzle 37 is formed along the inner wall surface 35. Specifically, the spinning nozzle 37 is linear and circular in cross section, and the radially outermost portion (hereinafter referred to as wall surface 37 b) of the wall surface of the spinning nozzle 37 is formed so as to be tangential to the circular inner wall surface 35. Hereinafter, this tangent line will be referred to as a nozzle tangent line 101. The center line of the spinning nozzle 37 is referred to as a nozzle center line 102. The nozzle tangential line 101 is parallel to the nozzle centerline 102, and the distance between the nozzle tangential line 101 and the nozzle centerline 102 is referred to as a 3 rd distance L3. In the present embodiment, the wall surface 37b coincides with the nozzle tangential line 101, and therefore the 3 rd distance L3 coincides with the radius of the spinning nozzle 37.

The spinning nozzle 37 may be formed slightly away from the axial center as compared with the present embodiment. For example, the spinning nozzle 37 may be formed so that the nozzle tangential line 101 coincides with the nozzle center line 102. That is, the 3 rd distance L3 may be any value of 0 or more and not more than the radius of the spinning nozzle 37 as long as the nozzle tangential line 101 coincides with the nozzle central line 102 or the nozzle central line 102 is located on the shaft center side than the nozzle tangential line 101. In other words, when viewed in the axial center direction (i.e., in fig. 5), the nozzle center line 102 of the spinning nozzle 37 is tangent to the inner wall surface 35, or the nozzle center line 102 of the spinning nozzle 37 is tangent to the inner wall surface 35 by parallel movement of the spinning nozzle 37 to the radial outside or less.

In this way, by forming the spinning nozzle 37 so as to follow the inner wall surface 35, a swirling air flow along the inner wall surface 35 can be generated. By causing the swirling air flow along the inner wall surface 35 to act on the wound fiber 8b, the wound fiber 8b swirls so as to follow the inner wall surface 35, and therefore, the tension applied to the wound fiber 8b can be reduced while dispersing the wound fiber 8 b. Thereby, the winding fiber 8b is easily and uniformly wound around the core fiber 8a.

In addition, by forming the plurality of spinning nozzles 37 as in the present embodiment, the air ejected from the ejection port 37a collides with the air ejected from the other ejection port 37 a. Therefore, the swirling air flow can be generated also at the upstream side of the ejection port 37a in the fiber traveling direction. As a result, the swirling air flow along the inner wall surface 35 can be generated in a wide range of the swirling chamber 34. However, if the number of spinning nozzles 37 is too large, the air ejected from the ejection ports 37a may interfere with each other to cause turbulence of the swirling air flow. Therefore, the number of spinning nozzles 37 (ejection ports 37 a) is preferably 3 to 6. However, the number of spinning nozzles 37 may be 2 or less, or 7 or more. The spinning nozzle 37 may not be linear. In this case, the center line near the discharge port 37a may be the nozzle center line 102.

In order to exhibit the 1 st feature, the swirl chamber 34 is a cylindrical space having a constant diameter. Therefore, the inner wall surface 35 is parallel to the axis center as a whole. In other words, in a cross section (for example, fig. 6) cut by an arbitrary plane parallel to the axis center, the angle formed by the axis center line 103 indicating the position of the axis center and the virtual extension line of the inner wall surface 35 is 0 °. The angle formed by the axis center line 103 and the virtual extension line of the inner wall surface 35 may be any value within 1.5 °. For example, when the inner wall surface 35 is inclined so as to expand as approaching the downstream side, the axis center line 103 intersects with an imaginary extension line of the inner wall surface 35 at a position upstream of the inner wall surface 35. The smaller of the two straight lines intersects is the angle formed by the two straight lines. On the other hand, when the inner wall surface 35 is inclined so as to expand as approaching the upstream side, the axis center line 103 intersects with an imaginary extension line of the inner wall surface 35 at a position downstream of the inner wall surface 35. The smaller of the two straight lines intersects is the angle formed by the two straight lines. In either case, the angle is equal to 0 °, or a positive value greater than 0 ° and less than 90 °.

If a step or taper is formed in the swirl chamber, the swirl flow is further away from the inner wall surface or the flow is disturbed as it is further away from the discharge port even if the swirl flow is along the inner wall surface in the vicinity of the discharge port. In this regard, since the diameter of the swirl chamber 34 is constant in the present embodiment, a swirling air flow along the inner wall surface 35 can be generated in the entire fiber traveling direction.

With the above configuration, the swirl chamber 34 can exhibit the above-described feature 1. In order to cause such a swirling air flow along the inner wall surface 35 to act on the wound fiber 8b, the air spinning device 9 also has a condition related to the 2 nd distance and a condition related to the effective length h.

The 2 nd distance L2 refers to a component of the distance from the downstream end (1 st plane 31 a) of the fiber guide member 31 to the upstream end of the hollow guide shaft body 40 in a direction parallel to the shaft center. If the 2 nd distance L2 is too short, the entangled fiber 8b is difficult to reverse. If the 2 nd distance L2 is too long, the distance from the nip point to the hollow guide shaft 40 becomes long, and thus the fibers contained in the fiber bundle 8 are likely to fall off. Therefore, in the present embodiment, the 2 nd distance L2 is preferably not less than 0.3mm, and preferably not more than 2.0mm, not more than 3.0mm, not more than 5.0mm, not more than 7.0 mm. The swirl chamber 34 of the present embodiment is formed not only on the upstream side but also on the downstream side from the upstream end of the hollow guide shaft body 40.

The effective length h is a length (length along the axial center) that enables the swirling air flow to act on the wound fiber 8 b. The swirling air flow is also present on the upstream side of the ejection port 37a as described above, but is mainly present on the downstream side of the ejection port 37 a. Therefore, the effective length h is a length along the axial center from the ejection port 37a to the downstream end of the swirl chamber 34 in the fiber traveling direction. The effective length h is determined in such a way that the swirling air flow swirls from half a week to one week in the swirling chamber 34.

Specifically, the effective length h is represented by the nozzle angle θ. The nozzle angle θ is the smaller angle (angle formed by the virtual plane 104 and the nozzle center line 102) of the angles formed by the intersection of the virtual plane 104 perpendicular to the axial center and the nozzle center line 102 when viewed in the radial direction of the swirl chamber 34 (i.e., in fig. 6). When d is the diameter of the swirl chamber 34, it is preferable that "dpi/2tanθ.ltoreq.h.ltoreq.dpi/tanθ" is satisfied. In the case where the inner wall surface 35 is not strictly parallel to the axis center, for example, the diameter d at the formation position of the ejection port 37a is preferably used. A whirling airflow is generated at the formation position of the ejection port 37a, and whirling or the like of the wound fiber 8b is also generated.

dpi is the circumference of the inner wall surface 35. The swirling air flow flows along the inner wall surface 35 while maintaining the nozzle angle θ. When dpi/2tan θ=h holds, the swirling airflow swirls for half a cycle to the downstream end of the swirling chamber 34. When dpi/tan θ=h is established, the swirling airflow swirls one revolution up to the downstream end of the swirling chamber 34. Therefore, the above equation holds in the case where the swirling air flow swirls for half a week in the swirling chamber 34. Thereby, the wound fiber 8b can be rotated within an appropriate range.

Next, the structure of the air spinning device 9 for exhibiting the 2 nd characteristic will be described. Feature 2 means that the wound fiber 8b does not overlap with the wound fiber 8b supplied next.

As shown in fig. 6, the distance from the nip point of the front roller pair 25 to the upstream end (more specifically, the point of the upstream end and the shaft center) of the hollow guide shaft body 40 is referred to as a 1 st distance L1. The 1 st distance L1 is a straight line distance, not a distance along the actual travel path of the fiber bundle 8. The 1 st distance L1 is a length of a line segment in the three-dimensional space, but can be expressed as a length of a line segment in a diagram (fig. 6) observed in the axial direction of the front roller pair 25. The shorter the 1 st distance L1, the fewer the fibers are reversed and the smaller the amount of fibers wound. Since the quality of the spun yarn 10 is affected by too much or too little amount of the wound fiber, the 1 st distance L1 is set to an appropriate value according to the shape of the nozzle block 33, the nature of the raw material (fiber bundle 8), the count of the spun yarn 10 to be produced, and the like. Further, since the fiber bundle 8 is held at the nip point (one end of the 1 st distance L1) of the front roller pair 25, the 1 st distance L1 coincides with the maximum length of the wound fiber 8 b. Many individual fibers among the plurality of fibers contained in the fiber bundle 8 function as the core fiber 8a and the winding fiber 8b in one spun yarn 10, and thus the length of the winding fiber 8b is shorter than that of the individual fibers.

In the present embodiment, in order to exhibit the 2 nd characteristic (so that the wound fiber 8b does not overlap with the wound fiber 8b supplied next), the 1 st distance L1 is equal to or less than the perimeter of the swirl chamber 34. As shown in fig. 5, the wound fiber 8b swirls along the inner wall surface 35. By setting the 1 st distance L1 to be equal to or less than the perimeter of the swirl chamber 34, the length of the wound fiber 8b is also equal to or less than the perimeter of the swirl chamber 34, and the wound fiber 8b does not swirl along the inner wall surface 35 by one revolution. Therefore, the wound fiber 8b does not overlap with the wound fiber 8b supplied next. As a result, the entangled fibers 8b are dispersed, and therefore the entangled fibers 8b are easily and uniformly entangled with the core fibers 8a. Thus, the air spinning device 9 of the present embodiment has the 2 nd feature.

The 1 st distance L1 is, for example, preferably 19mm to 28mm, more preferably 19mm to 21 mm. When the 1 st distance L1 is 21mm, if the diameter d of the swirl chamber 34 is about 6.7mm, the 1 st distance l1=circumferential length is established. Therefore, if the diameter d is 6.7mm or more, the nozzle block 33 having this feature can be used in a configuration in which the 1 st distance L1 is 19mm or more and 21mm or less. When the 1 st distance L1 is 28mm, the 1 st distance l1=circumferential length is established if the diameter d of the swirl chamber 34 is about 9.0mm. From the above, the diameter d is preferably 6.7mm or more and less than 9.0mm. The diameter d is more preferably 7.0mm to 8.0 mm.

In the present embodiment, the 1 st and 2 nd features described above facilitate winding the wound fiber 8b around the core fiber 8a uniformly. Fig. 7 is a schematic view of a spun yarn 10 produced by the spinning method according to the present embodiment. With this spun yarn 10, since the winding force of the winding fiber 8b is gentle and the winding fiber 8b is uniformly wound around the core fiber 8a, the spun yarn 10 having a soft feel and a uniform appearance can be produced.

As described above, the spinning unit 2 of the present embodiment includes the draft device 7 and the air spinning device 9, and produces the spun yarn 10. The draft device 7 includes a front roller pair 25 for nipping and feeding the fiber bundle 8, and draft the fiber bundle 8 (draft step). The air spinning device 9 applies a whirling airflow to the fiber bundle 8 sent out by the draft device 7 to generate a spun yarn 10 (spinning step). The air spinning device 9 includes a nozzle block 33 and a hollow guide shaft body 40. The nozzle block 33 has a spinning nozzle 37 for ejecting air and an inner wall surface 35 forming a cylindrical swirl chamber 34, and a swirl air flow is generated in the swirl chamber 34 by the air ejected from the spinning nozzle 37. The hollow guide shaft body 40 is configured to pass the fiber bundle 8 passing through the swirl chamber 34, and the hollow guide shaft body 40 is mounted so that rotation about the shaft center of the air spinning device 9 as a rotation center is restricted during spinning. The entire inner wall surface 35 is disposed in parallel with respect to the axis center. The 1 st distance L1, which is the distance from the nip point of the front roller pair 25 to the upstream end of the hollow guide shaft body 40 in the fiber traveling direction, is equal to or less than the perimeter of the swirl chamber 34. When viewed from the axial center, the nozzle center line 102 of the spinning nozzle 37 is tangent to the inner wall surface 35, or the nozzle center line 102 of the spinning nozzle 37 is tangent to the inner wall surface 35 by moving in parallel with the spinning nozzle 37 radially outward. The diameter d of the swirl chamber 34 at the position where the ejection port 37a of the spinning nozzle 37 is formed is 6.7mm or more and less than 9.0mm.

Since the nozzle center line 102 and the inner wall surface 35 have the above-described relationship and the inner wall surface 35 of the swirl chamber 34 is provided in a parallel state with respect to the axial center, the swirling air flow along the inner wall surface 35 can be caused to act on the wound fiber 8b. Accordingly, since the winding fiber 8b rotates along the inner wall surface 35, the tension applied to the winding fiber 8b can be reduced while dispersing the winding fiber 8b, compared with a case where the winding fiber 8b rotates around the outer surface of the hollow guide shaft body 40. Since the 1 st distance L1 is equal to or less than the circumference of the swirl chamber 34, the wound fiber 8b is less likely to swirl around the swirl chamber 34, and is less likely to overlap with the wound fiber 8b to be fed next. In this regard, the entangled fibers 8b are also easily dispersed. When considering the general 1 st distance L1, it is more preferable that the diameter d of the swirl chamber 34 is in the above range. By dispersing or reducing the tension of the winding fiber 8b, the winding fiber 8b is easily and uniformly wound around the core fiber 8a. As a result, the spun yarn 10 having a soft touch and a uniform appearance can be produced.

In the spinning unit 2 of the present embodiment, in a cross section taken by an arbitrary plane parallel to the axis center, the axis center (axis center line 103) is parallel to the inner wall surface 35, or an angle formed by the axis center and an imaginary extension line of the inner wall surface 35 is within 1.5 °.

Accordingly, the parallelism between the axial center and the inner wall surface 35 is sufficiently high, and therefore, a swirling air flow with less turbulence along the inner wall surface 35 can be generated.

In the spinning unit 2 of the present embodiment, the effective length h along the axis center from the ejection port 37a to the downstream end of the swirl chamber 34 in the fiber traveling direction, dpi/2tan θ+.h+.pi/tan θ, with respect to the diameter d of the swirl chamber 34, the nozzle angle θ formed by the virtual plane 104 perpendicular to the axis center and the nozzle center line 102, is established.

Accordingly, the swirling air flow flowing along the nozzle angle θ swirls by half a circle to one circle in the swirling chamber 34, and therefore the wound fiber 8b can be swirled in an appropriate range.

In the spinning unit 2 of the present embodiment, the air spinning device 9 includes a fiber guide member 31 for guiding the fiber bundle 8 sent out by the draft device 7 toward the whirling chamber 34. The 2 nd distance L2 is 0.3mm or more and 7.0mm or less, wherein the 2 nd distance L2 is a component of a distance from a downstream end in a fiber traveling direction of the fiber guide member 31 to an upstream end in the fiber traveling direction of the hollow guide shaft body 40 in a direction parallel to an axial center of the hollow guide shaft body 40.

This can reduce the amount of fibers that are detached while reducing the tension applied to the wound fibers 8 b.

In the spinning unit 2 of the present embodiment, the number of spinning nozzles 37 formed in the nozzle block 33 is 3 to 6.

By forming the plurality of spinning nozzles 37 in this way, the air ejected from the ejection port 37a collides with the air ejected from the other ejection port 37a, and thereby a swirling air flow can be generated also at a position upstream of the ejection port 37a in the fiber traveling direction. Therefore, the swirling air flow along the inner wall surface 35 can be generated in a wide range of the swirling chamber 34. In addition, by not excessively increasing the number of spinning nozzles 37, turbulence of the swirling air flow can be reduced.

In the spinning unit 2 of the present embodiment, the 1 st distance L1 is 19mm to 28 mm.

This allows the spinning unit 2 to cope with spinning under various conditions.

The preferred embodiments of the present invention have been described above, but the above-described configuration can be modified as follows. The following modifications can be appropriately combined.

The needle member 32 may be omitted and the function of the needle member 32 may be exhibited by the downstream end portion of the fiber guiding member 31.

In place of the yarn accumulating device 14 or in addition to the yarn accumulating device 14, a yarn drawing roller that is rotationally driven and a grip roller that is pressed against the yarn drawing roller may be provided at a position downstream of the air spinning device 9, and the spun yarn 10 may be conveyed downstream while being sandwiched between the yarn drawing roller and the grip roller. In this case, a loose tube (slot tube) and/or a mechanical compensator using suction air flow may be provided downstream of the yarn drawing roller and the grip roller.

In the spinning unit 2, the devices are arranged so that the fiber passing direction is directed from the upper side to the lower side, but the devices may be arranged so that the fiber passing direction is directed from the lower side to the upper side.

The fiber guide member 31 and the nozzle block 33 may be integrally formed as one member.

The spinning unit 2 may be configured to carry the spun yarn 10 from the package 28 at least reversely to the air spinning device 9, and then start the drafting operation of the drafting device 7 and the spinning operation of the air spinning device 9, so that the spun yarn 10 which is disconnected is brought into a continuous state (so-called piecing).

The spinning machine 1 may not include the yarn joining carriage 3, and each spinning unit 2 may be provided with a structure for bringing the broken spun yarn 10 into a continuous state.

Claims (8)

1. A spinning unit, comprising:

a draft device configured to include a front roller pair for nipping and feeding out a fiber bundle and draft the fiber bundle; and

an air spinning device for generating spun yarn by applying a whirling air flow to the fiber bundle fed out from the draft device,

the air spinning device comprises:

a nozzle block having a spinning nozzle for ejecting air and an inner wall surface of a swirl chamber formed in a cylindrical shape, and generating a swirl flow in the swirl chamber by the air ejected from the spinning nozzle; and

A hollow guide shaft body through which the fiber bundle having passed through the swirl chamber passes, the hollow guide shaft body being mounted so that rotation about a shaft center of the air spinning device as a rotation center is restricted during spinning,

the whole of the inner wall surface is disposed in a parallel state with respect to the shaft center,

the 1 st distance from the nip point of the front roller pair to the upstream end of the hollow guide shaft body in the fiber traveling direction is equal to or less than the perimeter of the swirl chamber,

when viewed from the axis center, the nozzle center line of the spinning nozzle is tangent to the inner wall surface, or the nozzle center line of the spinning nozzle is tangent to the inner wall surface by parallel movement of the spinning nozzle having a radius or less radially outward,

the diameter of the swirl chamber at the position where the ejection port of the spinning nozzle is formed is 6.7mm or more and less than 9.0mm,

the air spinning device comprises a fiber guiding component for guiding the fiber bundle sent out by the drafting device to the whirling chamber,

a 2 nd distance is 0.3mm or more and 7.0mm or less, wherein the 2 nd distance is a component of a distance from a downstream end in a fiber traveling direction of the fiber guiding member to an upstream end in the fiber traveling direction of the hollow guiding shaft body in a direction parallel to an axial center of the hollow guiding shaft body.

2. A spinning unit according to claim 1, wherein,

in a cross section taken by an arbitrary plane parallel to the axis center, the axis center is parallel to the inner wall surface, or an angle formed by the axis center and an imaginary extension line of the inner wall surface is within 1.5 °.

3. A spinning unit according to claim 1, wherein,

the diameter of the swirl chamber is d,

A nozzle angle, which is an angle formed by a plane perpendicular to the axial center and the nozzle center line when viewed in the radial direction of the swirl chamber, is set to be θ,

When the length from the ejection port to the downstream end of the swirl chamber in the fiber traveling direction along the axial center is set to h,

dpi/2tanθ is equal to or more than h and equal to or less than dpi/tanθ.

4. A spinning unit according to claim 2, wherein,

the diameter of the swirl chamber is d,

A nozzle angle, which is an angle formed by a plane perpendicular to the axial center and the nozzle center line when viewed in the radial direction of the swirl chamber, is set to be θ,

When the length from the ejection port to the downstream end of the swirl chamber in the fiber traveling direction along the axial center is set to h,

dpi/2tanθ is equal to or more than h and equal to or less than dpi/tanθ.

5. A spinning unit according to any one of claims 1 to 4, wherein,

the number of the spinning nozzles formed in the nozzle block is 3 to 6.

6. A spinning unit according to any one of claims 1 to 4, wherein,

the 1 st distance is 19mm to 28 mm.

7. A spinning unit according to claim 5, wherein,

the 1 st distance is 19mm to 28 mm.

8. A method of manufacturing a spun yarn, comprising the steps of:

a drawing step of drawing the fiber bundle by a drawing device including a front roller pair for nipping and feeding the fiber bundle; and

a spinning step of producing a spun yarn by an air spinning device that causes a swirling air flow to act on the fiber bundle fed out from the draft device,

the method for producing the spun yarn is characterized in that,

the air spinning device comprises:

a nozzle block having a spinning nozzle for ejecting air and an inner wall surface of a swirl chamber formed in a cylindrical shape, and generating a swirl flow in the swirl chamber by the air ejected from the spinning nozzle; and

a hollow guide shaft body through which the fiber bundle having passed through the swirl chamber passes, the hollow guide shaft body being mounted so that rotation about a shaft center of the air spinning device as a rotation center is restricted during spinning,

The whole of the inner wall surface is disposed in a parallel state with respect to the shaft center,

the 1 st distance from the nip point of the front roller pair to the upstream end of the hollow guide shaft body in the fiber traveling direction is equal to or less than the perimeter of the swirl chamber,

when viewed from the axis center, the nozzle center line of the spinning nozzle is tangent to the inner wall surface, or the nozzle center line of the spinning nozzle is tangent to the inner wall surface by parallel movement of the spinning nozzle to the axis center side of the spinning nozzle having a radius or less,

the diameter of the swirl chamber at the position where the ejection port of the spinning nozzle is formed is 6.7mm or more and less than 9.0mm,

the air spinning device comprises a fiber guiding component for guiding the fiber bundle sent out by the drafting device to the whirling chamber,

a 2 nd distance is 0.3mm or more and 7.0mm or less, wherein the 2 nd distance is a component of a distance from a downstream end in a fiber traveling direction of the fiber guiding member to an upstream end in the fiber traveling direction of the hollow guiding shaft body in a direction parallel to an axial center of the hollow guiding shaft body.

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