CN110129927B

CN110129927B - Centrifugal spinning method and centrifugal spinning frame

Info

Publication number: CN110129927B
Application number: CN201910085007.0A
Authority: CN
Inventors: 宫田康广; 槌田大辅
Original assignee: Toyota Industries Corp
Current assignee: Toyota Industries Corp
Priority date: 2018-02-09
Filing date: 2019-01-29
Publication date: 2021-08-17
Anticipated expiration: 2039-01-29
Also published as: EP3524715A1; JP2019137937A; JP6881345B2; EP3524715B1; CN110129927A

Abstract

The centrifugal spinning method of the present invention comprises: a step of forming a yarn cake (28) by rotating a tank (12) having an opening (23) and winding a yarn (18) stretched to a predetermined fineness around an inner wall (22) of the tank (12); a step of arranging a bobbin (25) in the tank (12) through the opening (23); blowing compressed air to a region of the inner wall (22) of the tank (12) closer to the opening (23) than the end of the yarn cake (28) closer to the opening (23), thereby discharging the yarn part existing in the region to the outside of the tank (12); and a step of rewinding the yarn forming the yarn cake (28) from the inner wall (22) of the tank (12) to the bobbin (25) with the yarn portion discharged outside the tank (12) as a rewinding starting point portion.

Description

Centrifugal spinning method and centrifugal spinning frame

Technical Field

The invention relates to a centrifugal spinning method and a centrifugal spinning frame.

Background

As one spinning method, a centrifugal spinning method using a cylindrical tank is known. Patent document 1 describes a technique related to a centrifugal spinning method and a centrifugal spinning machine. In the technique described in patent document 1, a cylindrical bobbin is disposed coaxially with a yarn guide tube outside the yarn guide tube, and a notch portion is formed at one end of the bobbin. Then, the yarn spun from the yarn guide tube is twisted while the yarn is wound around the inner wall of the can to form a yarn cake, and then the yarn is hooked in the notch by projecting one end of the bobbin in the axial direction, thereby starting rewinding the yarn onto the bobbin.

Patent document 1: japanese laid-open patent publication No. 8-325854

However, the technique described in patent document 1 has the following problems.

The bobbin used in the technique described in patent document 1 has a special structure in which one end of the bobbin is formed to expand like a skirt and a notch is formed therein. In the technique described in patent document 1, a flange portion is formed on an upper portion of the bobbin, and a locking means is locked to the flange portion to hold a position of the bobbin. Therefore, the bobbin used in the technique described in patent document 1 has a special structure with a flange.

Therefore, in the technique described in patent document 1, for example, when a centrifugal spinning machine is newly introduced into an existing spinning factory in which a ring spinning machine has been introduced, it is necessary to prepare a dedicated bobbin for the centrifugal spinning yarn separately from a bobbin used for the ring spinning. In addition, a winder or the like that handles bobbins drawn out of a centrifugal spinning machine needs to have a special specification in accordance with the structure of the bobbins. Therefore, the cost associated with the introduction of the centrifugal spinning machine increases.

Disclosure of Invention

The present invention has been made to solve the above-described problems, and an object thereof is to provide a centrifugal spinning method and a centrifugal spinning machine capable of appropriately rewinding a bobbin without using a bobbin having a special structure.

The centrifugal spinning method of the present invention has the steps of:

rotating a tank having an opening and winding a yarn drawn to a predetermined fineness around an inner wall of the tank to form a yarn cake;

disposing a bobbin in the tank through the opening;

blowing compressed air to a region of the inner wall of the tank on the opening side of the end of the yarn cake on the opening side, thereby discharging the yarn part existing in the region to the outside of the tank; and

the yarn portion discharged to the outside of the tank is used as a rewind starting point portion, and the yarn forming the yarn cake is rewound from the inner wall of the tank to the bobbin.

In the centrifugal spinning method according to the present invention, the tank may be rotated at a first rotation speed when the cake is formed, and the tank may be rotated at a second rotation speed lower than the first rotation speed when the compressed air is blown.

Further, the compressed air may be blown at an angle of 20 degrees or more and 60 degrees or less toward the opening portion with respect to the inner wall of the tank.

Further, the method may include: the yarn portion serving as the rewind starting point portion is wound around the inner wall of the can in a region closer to the opening portion than an end portion on the winding end side of the yarn package.

Further, the yarn strength of the yarn portion that becomes the backrush starting point portion may be higher than the yarn strength of the yarn portion that forms the yarn cake.

The centrifugal spinning frame of the invention comprises:

a yarn guide tube;

a can having an opening located on the opposite side of the yarn guide tube, into which a part of the yarn guide tube is inserted from the opposite side of the opening; and

a bobbin that is disposed so as to face the yarn guide tube in a central axis direction of the can and that is inserted into the can from the opening of the can,

a yarn drawn to a predetermined fineness is wound around an inner wall of the tank by the operation of the yarn guide tube and the tank to form a yarn cake, and the yarn forming the yarn cake is rewound from the inner wall of the tank to the bobbin, in the centrifugal spinning machine,

an air nozzle inserted into the tank together with the bobbin and blowing compressed air toward an inner wall of the tank,

the air nozzle discharges the yarn portion existing in a region closer to the opening portion side than an end portion of the yarn cake located on the opening portion side, out of the tank, by blowing compressed air in the region.

Drawings

Fig. 1 is a schematic diagram showing a configuration example of a main part of a centrifugal spinning machine according to an embodiment of the present invention.

Fig. 2 is a partially enlarged view illustrating the arrangement of the air nozzles.

Fig. 3 is a block diagram showing a configuration example of a drive control system of a centrifugal spinning machine according to an embodiment of the present invention.

Fig. 4 is a diagram showing a basic flow of a centrifugal spinning method.

Fig. 5 is a cross-sectional view illustrating a first state of a centrifugal spinning method according to an embodiment of the present invention.

Fig. 6 is a diagram for explaining the operation of the yarn guide tube.

Fig. 7 is a cross-sectional view illustrating a second state of the centrifugal spinning method according to the embodiment of the present invention.

Fig. 8 is a cross-sectional view illustrating a third state of the centrifugal spinning method according to the embodiment of the present invention.

Fig. 9 is a cross-sectional view illustrating a fourth state of the centrifugal spinning method according to the embodiment of the present invention.

Fig. 10 is a cross-sectional view illustrating a fifth state of the centrifugal spinning method according to the embodiment of the present invention.

Fig. 11 is a sectional view illustrating a sixth state of the centrifugal spinning method according to the embodiment of the present invention.

Fig. 12 is a sectional view illustrating a second embodiment of the present invention.

Description of the reference numerals

A centrifugal spinning frame; a yarn guide tube; a can; a yarn; inner wall; an opening portion; a bobbin; a yarn cake; a terminal end (end portion on the winding end side); an air nozzle; a spout; compressing air; 33. a control section (spinning condition changing section); 53.. a yarn guide tube driving part; a canister drive portion; 61.. an air nozzle; a spout.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

< centrifugal spinning frame >

First, a centrifugal spinning machine according to an embodiment of the present invention will be described.

As shown in fig. 1, a centrifugal spinning machine 1 includes: a draft device 10, a yarn guide tube 11, a can 12, and a bobbin support portion 13. These components constitute one spindle which is one unit of a spun yarn. The centrifugal spinning machine 1 includes a plurality of spindles, and a structure of one of the spindles will be described here.

(drawing device)

The draft device 10 is a device for drawing a yarn material such as a roving to a predetermined fineness. The draft device 10 is configured using a plurality of roller pairs including a back roller pair 15, a middle roller pair 16, and a front roller pair 17. The plurality of roller pairs are arranged in the order of a rear roller pair 15, a middle roller pair 16, and a front roller pair 17 from the upstream side toward the downstream side in the yarn material conveyance direction.

The roller pairs 15, 16, and 17 are rotated by driving of a draft driving unit described later. When the rotation speeds (rpm) per unit time of the

respective roller pairs

15, 16, 17 are compared, the rotation speed of the middle roller pair 16 is higher than that of the rear roller pair 15, and the rotation speed of the front roller pair 17 is higher than that of the middle roller pair 16. In this way, the rotation speeds of the

roller pairs

15, 16, and 17 are different from each other, and the draft device 10 draws the yarn material to be thin by the rotation speed difference. In the following description, the rotation speed of the roller pair is also referred to as a rotation speed. The rotation speed of the roller pair is in direct proportion to the rotation speed.

(guide bobbin)

The yarn guide tube 11 guides the yarn 18 drawn to a predetermined fineness by the draft device 10 into the tank 12. The yarn guide tube 11 is formed into an elongated tubular shape. The shape of the yarn guide tube 11 cut in a direction orthogonal to the longitudinal direction is circular.

The yarn guide tube 11 is arranged coaxially with the can 12 on the downstream side of the draft device 10. The lower part of the yarn guide tube 11 is inserted into the tank 12. The yarn guide tube 11 guides the yarn 18 supplied from the front roller pair 17 through the yarn supply tube 14 into the tank 12. The yarn 18 stretched by the draft device 10 is introduced into the yarn supply tube 14 by, for example, a swirling flow of air, and then introduced into the yarn guide tube 11 through the yarn supply tube 14. The yarn 18 introduced into the yarn guide tube 11 is spun from the lower end 11a of the yarn guide tube 11. The yarn guide tube 11 is provided to be movable in the vertical direction by a yarn guide tube driving unit described later.

A yarn sensor 19 is disposed between the front roller pair 17 and the yarn supply pipe 14. The yarn sensor 19 is a sensor for detecting the state of the yarn drawn by the draft device 10. In the present embodiment, a broken yarn is given as an example of the state of the yarn detected by the yarn sensor 19. In the present embodiment, the yarn sensor 19 is configured by using an optical sensor in which a light emitter 19a and a light receiver 19b are combined, as an example.

(Pot (ポット))

The canister 12 is used for the formation of the cake 28 and the rewinding of the yarn. The tank 12 is formed in a cylindrical shape. The tank 12 is provided to be rotatable about a central axis of the tank 12. The center axis K of the tank 12 is arranged parallel to the vertical direction. Therefore, one direction of the central axis direction of the tank 12 is the upper direction, and the other direction is the lower direction.

The tank 12 is rotated by the driving of a tank driving unit described later. A yarn guide insertion opening 21 is formed at the upper end side of the can 12. The bobbin insertion opening 21 is an opening for inserting the bobbin 11 into the can 12. An opening 23 is formed at the lower end of the tank 12. The bobbin insertion opening 21 is opened upward with a diameter smaller than a diameter (hereinafter referred to as "can inner diameter") based on the position of the inner wall 22 defining the inner volume of the can 12. The opening 23 is opened downward with the same diameter as the inner diameter of the can.

(bobbin supporting part)

The bobbin support portion 13 supports the bobbin 25. The bobbin supporting portion 13 has a bobbin base 26 and a bobbin mounting portion 27. The bobbin base 26 is formed in a plate shape. The bobbin mounting portion 27 is fixed to the bobbin base 26. The bobbin mounting part 27 is formed in a columnar shape and is arranged to protrude upward from the upper surface of the bobbin base 26.

The bobbin mounting portion 27 is a portion to which the bobbin 25 is detachably mounted. The bobbin mounting portion 27 is disposed coaxially with the yarn guide tube 11 and the tank 12 so as to face the yarn guide tube 11 in the central axis direction of the tank 12. The bobbin mounting portion 27 is disposed below the yarn guide tube 11. Therefore, when the bobbin 25 is attached to the bobbin attachment portion 27, the bobbin 25 is disposed to face the yarn guide tube 11 on the central axis K of the can 12.

The bobbin 25 has a tapered structure in which the outer circumference of the bobbin continuously changes from one end side to the other end side in the bobbin center axis direction. The bobbin 25 corresponds to a general bobbin used also for ring spinning and the like. The bobbin 25 has a hollow structure at least at one end. The bobbin 25 is supported by fitting a hollow portion at one end side to the bobbin mounting portion 27 so as to be vertically erected from the bobbin base 26.

The bobbin supporting portion 13 is provided to be movable in the vertical direction by a bobbin driving portion described later. The outer circumference of the bobbin 25 is set to be smaller than the minimum diameter of the cake 28 formed on the inner wall 22 of the tank 12. This can prevent the bobbin 25 from contacting the cake 28 when the bobbin 25 is inserted and arranged in the tank 12 through the opening 23 of the tank 12.

(air nozzle)

The centrifugal spinning machine 1 according to the embodiment of the present invention includes the air nozzle 31 in addition to the above-described components. The air nozzle 31 blows compressed air to a region 22a on the opening 23 side of the end 28b on the winding completion side of the yarn cake 28 formed on the inner wall 22 of the can 12 by the operation of the yarn guide tube 11 and the can 12. The air nozzle 31 discharges the yarn portion, which is the yarn rewinding starting point portion to the bobbin 25, of the region 22a wound in the tank 12 to the outside of the tank 12 by the compressed air blow.

The rewind starting point is a portion of the yarn that is wound around the bobbin 25 first when the yarn that forms the cake 28 is rewound into the bobbin 25. Therefore, the rewinding to the bobbin 25 is started when the yarn portion serving as the rewinding starting point portion is wound around the bobbin 25. In the present embodiment, of the yarns wound around the inner wall 22 of the can 12, the portion of the yarn wound between the end portion of the yarn package 28 on the winding end side and the opening 23 in the central axis direction of the can 12 serves as a rewind starting point portion. Further, the end of the yarn package 28 on the winding end side corresponds to the end of the yarn package 28 on the opening 23 side, as viewed in the direction of the center axis of the can 12.

The air nozzle 31 is provided in the bobbin support portion 13. The air nozzle 31 is attached to the bobbin base 26. The air nozzle 31 is disposed in the vicinity of the bobbin mounting portion 27 so as to stand vertically from the bobbin base 26.

The air nozzle 31 has an ejection port 32 that ejects compressed air. The discharge port 32 of the air nozzle 31 is disposed near the upper end of the air nozzle 31. The compressed air discharged from the discharge port 32 of the air nozzle 31 is blown toward the opening 23 of the tank 12 and obliquely toward the inner wall 22 of the tank 12 by the driving of a bobbin driving unit and an air nozzle driving unit, which will be described later.

Here, as shown in fig. 2, when the compressed air 33 is blown from the air nozzle 31 toward the inner wall 22 of the tank 12, the blowing angle θ of the compressed air 33 with respect to the inner wall 22 of the tank 12 has a predetermined inclination angle on the opening 23 side. The blowing angle θ of the compressed air 33 is preferably 20 degrees or more and 60 degrees or less, and more preferably 30 degrees or more and 45 degrees or less. By setting the blowing angle θ of the compressed air 33 in this way, the distance L suitable for blowing the compressed air 33 can be easily ensured between the inner wall 22 of the tank 12 and the air nozzle 31.

As shown in fig. 3, the centrifugal spinning machine 1 includes a control unit 51, a draft drive unit 52, a yarn guide tube drive unit 53, a can drive unit 54, a bobbin drive unit 55, and a nozzle drive unit 56.

(control section)

The control section 51 comprehensively controls the overall operation of the centrifugal spinning machine 1. The control section 51 electrically connects the draft driving section 52, the yarn guide driving section 53, the can driving section 54, the bobbin driving section 55, and the nozzle driving section 56 to control the operation. The yarn sensor 19 is electrically connected to the control unit 51. When a yarn break occurs in the draft device 10, the yarn sensor 19 outputs a yarn break generation signal notifying that the yarn break occurs to the control unit 51.

(draft drive section)

The draft driving section 52 rotates the rear roller pair 15, the middle roller pair 16, and the front roller pair 17 at predetermined rotational speeds. The draft driving section 52 rotates the rear roller pair 15, the middle roller pair 16, and the front roller pair 17 by driving based on a draft driving signal supplied from the control section 51 to the draft driving section 52.

(yarn guide tube drive unit)

The yarn guide driving unit 53 operates the yarn guide 11. The yarn guide driving unit 53 operates to move the yarn guide 11 in the vertical direction. The yarn guide driving unit 53 is driven based on a yarn guide driving signal given from the control unit 51 to the yarn guide driving unit 53, thereby moving the yarn guide 11 in the vertical direction.

(tank driving part)

The tank driving unit 54 rotates the tank 12. The tank driving unit 54 rotates the tank 12 around the central axis K of the tank 12 as the rotation center by driving based on a tank driving signal given from the control unit 51.

(bobbin driving part)

The bobbin drive section 55 operates the bobbin 25. The bobbin driving section 55 operates the bobbin 25 attached to the bobbin attachment section 27 of the bobbin support section 13 so as to move in the vertical direction integrally with the bobbin support section 13 and the air nozzle 31. The bobbin driving section 55 moves the bobbin 25 in the vertical direction by driving based on a bobbin driving signal given from the control section 51.

(nozzle drive part)

The nozzle drive unit 56 operates the air nozzle 31. The nozzle driving unit 56 operates to eject compressed air from the discharge port 32 of the air nozzle 31. The nozzle driving unit 56 is driven based on a nozzle driving signal given from the control unit 51, and thereby discharges compressed air from the air nozzle 31.

< centrifugal spinning method >

Next, a centrifugal spinning method according to an embodiment of the present invention will be described.

Fig. 4 is a diagram showing a basic flow of a centrifugal spinning method.

As shown in fig. 4, the centrifugal spinning method includes a stretching step S1, a cake forming step S2, and a rewinding step S3.

The drawing step S1 is a step of drawing a yarn material such as a roving to a predetermined fineness. The yarn cake forming step S2 is a step of winding the yarn drawn to a predetermined fineness in the drawing step S1 around the inner wall 22 of the can 12 to form the yarn cake 28. The rewinding step S3 is a step of rewinding the yarn forming the cake 28 into the bobbin 25. The operation of the centrifugal spinning machine 1 according to each step will be described below.

Before the centrifugal type spinning machine 1 is operated, the yarn guide tube 11 is disposed close to the yarn supply tube 14, the bobbin 25 is attached to the bobbin mounting portion 27 of the bobbin support portion 13, and the bobbin 25 is disposed so as to be retracted downward from the tank 12.

(stretching step)

The stretching step S1 is performed using the draft device 10. The draft driving section 52 rotates the rear roller pair 15, the middle roller pair 16, and the front roller pair 17 at predetermined rotational speeds by driving based on a draft driving signal supplied from the control section 51. Thereby, the yarn material such as roving is conveyed by the rotation of the roller pairs 15, 16, and 17.

At this time, the control section 51 sets the rotation speed of the rear roller pair 15 to a speed lower than the rotation speed of the middle roller pair 16, and sets the rotation speed of the middle roller pair 16 to a speed lower than the rotation speed of the front roller pair 17. Thereby, the yarn is stretched between the back roller pair 15 and the middle roller pair 16 due to the difference in the rotational speed of the roller pairs. Similarly, between the middle roller pair 16 and the front roller pair 17, the yarn is also stretched due to the difference in the rotational speed of the roller pairs.

As a result, the yarn material such as roving is drawn to a predetermined fineness while passing through the rear roller pair 15, the middle roller pair 16, and the front roller pair 17 in this order. The yarn 18 thus stretched is then introduced into the yarn supply tube 14 by the swirling flow of air, and then introduced into the yarn guide tube 11.

Before the start of the drawing step S1, the control unit 51 gives a can driving signal to the can driving unit 54 to rotate the can 12 at a predetermined number of revolutions.

(yarn cake formation step)

The yarn cake forming step S2 is performed using the yarn guide tube 11 and the can 12. The yarn guide driving unit 53 drives the yarn guide 11 in accordance with a yarn guide driving signal given from the control unit 51, thereby moving the yarn guide 11 downward by a predetermined amount. The tank driving unit 54 continues the rotation of the tank 12 by driving based on a tank driving signal given from the control unit 51. When the yarn guide tube 11 is moved downward, the yarn guide tube 11 is separated from the yarn supply tube 14. The yarn 18 introduced into the yarn guide tube 11 from the yarn supply tube 14 is spun from the lower end portion 11a of the yarn guide tube 11.

The yarn 18 spun out from the lower end portion 11a of the yarn guide tube 11 is subjected to a centrifugal force generated by the rotation of the tank 12, and the yarn 18 is pressed against the inner wall 22 of the tank 12 by the centrifugal force. The yarn 18 pressed against the inner wall 22 of the tank 12 is twisted by the rotation of the tank 12. As a result, the yarn 18 spun from the lower end 11a of the yarn guide tube 11 is wound around the inner wall 22 of the can 12 in a twisted state by the rotation of the can 12.

Further, the yarn guide driving section 53 is driven based on the yarn guide driving signal, and thereby, as shown in fig. 5, the position of the yarn guide tube 11 is displaced relatively downward while reciprocating the yarn guide tube 11 in the vertical direction repeatedly at a predetermined cycle. Thereby, a yarn cake 28 is formed on the inner wall 22 of the can 12. The yarn cake 28 is a laminate formed by the yarn 18 wound around the inner wall 22 of the can 12.

Fig. 6 is a diagram illustrating an operation of the yarn guide tube in the yarn cake forming step. In the figure, the vertical axis represents the position of the yarn guide tube in the direction of the central axis of the can, and the horizontal axis represents time.

In fig. 6, the yarn guide tube 11 first descends to the P1 position, then ascends to the P2 position, then descends to the P3 position, and then ascends to the P4 position. In other words, the yarn guide tube 11 repeatedly reciprocates in the up-down direction. In this case, a period T1 from when the yarn guide tube 11 reaches the position P1 to when it reaches the position P3 and a period T2 from when the yarn guide tube 11 reaches the position P2 to when it reaches the position P4 are each one cycle. Further, since the position of the yarn guide tube 11 is displaced relatively downward, the P3 position is lower than the P1 position, and the P4 position is lower than the P2 position. The amounts of vertical displacement H1 of the P1 position and the P3 position and the amounts of vertical displacement H2 of the P2 position and the P4 position correspond to the amounts of displacement of the yarn guide tube 11 for one cycle. In other words, the yarn guide tube 11 is displaced downward by a constant displacement amount each time while repeating reciprocating movement in the vertical direction at a constant cycle. The operation of the yarn guide tube 11 continues until the yarn guide tube 11 reaches the Pm position. In this case, the P1 position defines the end 28a of the yarn cake 28 shown in fig. 1 on the winding start side, and the Pm position defines the end 28b of the yarn cake 28 shown in this figure on the winding end side.

The control unit 51 gives a yarn guide driving signal to the yarn guide driving unit 53 to operate the yarn guide 11 as shown in fig. 5 and 6. Thus, a yarn cake 28 is formed on the inner wall 22 of the tank 12 in the shape shown in fig. 5. In the present embodiment, the cake forming step S2 includes the following steps after the cake 28 is formed by the operation of the yarn guide tube 11.

The control unit 51 moves the yarn guide tube 11 downward by a predetermined amount Lh after the yarn guide tube 11 reaches the position Pm. As a result, as shown in fig. 7, the yarn portion 18a serving as a winding start point portion to the bobbin 25 is wound around the inner wall 22 of the can 12 in the region 22a on the opening 23 side of the terminal end 28b of the yarn cake 28. The yarn portion 18a may be wound in a single layer or in multiple layers. When the yarn portion 18a is wound in a single layer, the yarn cutting may be performed while the yarn guide tube 11 is being lowered from the Pm position to the Pn position. When the yarn portion 18a is wound in multiple layers, yarn cutting may be performed at least at 1 time after the yarn guide tube 11 is lowered from the Pm position to the Pn position and then raised to a position higher than the Pn position. The predetermined amount Lh is preferably 3mm to 7 mm.

Here, differences between "cut yarn" and "broken yarn" will be described.

The yarn cutting is an operation intentionally performed at a stage when a predetermined amount of the yarn 18 is wound around the inner wall 22 of the tank 12. In contrast, yarn breakage is a phenomenon in which the yarn 18 is broken halfway due to some reason before the predetermined amount of the yarn 18 is wound around the inner wall 22 of the tank 12.

The cutting is performed under the control of the control section 51. Specifically, the control section 51 controls the driving of the draft driving section 52 so as to stop the rotation of the back roller pair 15 and the middle roller pair 16 together with the continuous rotation of the front roller pair 17. Thereby, the yarn 18 is forcibly cut at the downstream side of the middle roller pair 16.

Further, the control section 51 changes the spinning conditions so that the yarn strength of the yarn portion 18a which becomes the rewinding starting point portion rewinding to the bobbin 25 is higher than the yarn strength of the yarn portion forming the cake 28 at the time of yarn cutting. In this case, the control unit 51 corresponds to a spinning condition changing unit. The thicker the thickness of the yarn, the stronger the yarn strength. In addition, the more twist the yarn, the stronger the yarn strength. The number of spinning conditions to be changed to enhance the yarn strength may be one or more. In the present embodiment, the rotation speed of the front roller pair 17 is described as an example of the spinning conditions to be changed. When the rotation speed of the front roller pair 17 is changed, the rotation speed difference between the middle roller pair 16 and the front roller pair 17 changes correspondingly.

Therefore, the control section 51 decelerates the rotational speed of the front roller pair 17 so as to strengthen the yarn strength of the yarn portion 18a serving as the rewind starting point portion as described above. When the rotation speed of the front roller pair 17 is reduced, the rotation speed difference between the middle roller pair 16 and the front roller pair 17 becomes small. Further, since the speed of the yarn fed from the front roller pair 17 is slow, the number of twists also increases. Thereby, the thickness of the yarn 18 drawn by the draft device 10 becomes thicker. Therefore, when the predetermined yarn 18 wound around the region 22a of the inner wall 22 of the tank 12 passes through the draft device 10, the rotation speed of the front roller pair 17 is decelerated, whereby the yarn strength of the yarn portion 18a serving as the back-winding start point portion can be increased.

The cake forming step S2 performs cake formation and yarn cutting as described above, and ends the end of the yarn produced by the yarn cutting at the stage of being wound around the inner wall 22 of the can 12.

(step of rewinding)

The rewinding step S3 is performed using the tank 12, the bobbin 25, and the air nozzle 31. In the rewinding step S3, the bobbin 25 and the air nozzle 31 are disposed in the tank 12 through the opening 23 by the driving of the tank driving unit 54. The tank driving unit 54 continues the rotation of the tank 12 by being driven based on a tank driving signal given from the control unit 51. As shown in fig. 9, the bobbin driving section 55 moves the bobbin supporting section 13 upward by driving based on a bobbin driving signal given from the control section 51. Thereby, the bobbin 25 attached to the bobbin attachment portion 27 (see fig. 1) moves upward together with the air nozzle 31 attached to the bobbin base 26. Further, the pipe 25 and the air nozzle 31 enter the tank 12 through the opening 23 of the tank 12. At this time, the discharge port 32 of the air nozzle 31 is arranged obliquely downward toward the inner wall 22 of the tank 12. On the other hand, as shown in fig. 9, the yarn guide driving unit 53 drives the yarn guide 11 upward based on a yarn guide driving signal given from the control unit 51. Thus, the lower end 11a of the yarn guide tube 11 is retracted to a position not in contact with the bobbin 25 before the bobbin 25 enters the tank 12.

Next, as shown in fig. 10, the control unit 51 gives a nozzle drive signal to the nozzle drive unit 56, thereby ejecting the compressed air 33 from the ejection port 32 of the air nozzle 31. The ejection time of the compressed air 33 may be set to be, for example, in a range of 0.2 seconds to 2 seconds. Thereby, the compressed air 33 ejected from the ejection port 32 of the air nozzle 31 is blown toward the inner wall 22 of the tank 12. The blowing angle θ (see fig. 2) of the compressed air 33 is preferably 20 degrees or more and 60 degrees or less, and more preferably 40 degrees or more and 50 degrees or less toward the opening 23 side with respect to the inner wall 22 of the tank 12. The compressed air 33 ejected from the air nozzle 31 is blown to the yarn portion wound on the opening 23 side of the terminal end 28b of the yarn cake 28, that is, the yarn portion 18a serving as a winding start point portion to be wound around the bobbin 25. Thus, the yarn portion 18a is pressed by the compressed air 33 and discharged from the opening 23 of the tank 12 to the outside of the tank 12.

The control unit 51 controls the driving of the tank driving unit 54 so that the rotation speed of the tank 12 is relatively reduced when the compressed air 33 is blown. Specifically, the rotation speed of the tank 12 when the cake 28 is formed is set to a first rotation speed (rpm), and the rotation speed of the tank 12 when the compressed air is blown is set to a second rotation speed (rpm). In this case, the control unit 51 controls the driving of the tank driving unit 54 so that the second rotation speed is lower than the first rotation speed. Here, when the first rotation speed is a (rpm) and the second rotation speed is B (rpm), the controller 51 can control the driving of the tank driver 54 so as to preferably satisfy the condition "0.6A ≦ B ≦ 0.8A".

By controlling the rotation speed of the tank 12 in this way, the force with which the yarn is pressed against the inner wall 22 of the tank 12, i.e., the centrifugal force, is weakened when the compressed air is blown. Therefore, when the compressed air 33 is blown from the air nozzle 31, the yarn portion 18a is easily peeled from the inner wall 22 of the tank 12. Therefore, the yarn portion 18a can be discharged to the outside of the tank 12 with a smaller force than in the case where the rotation speed of the tank 12 is not reduced. Further, by reducing the rotation speed of the tank 12, the tension applied to the yarn becomes small. Therefore, the yarn portion 18a discharged to the outside of the tank 12 by the compressed air 33 is less likely to be broken. Therefore, the risk of a package failure due to yarn breakage can be reduced.

As described above, when the yarn portion 18a serving as the winding start point portion for winding the yarn around the bobbin 25 is discharged outside the tank 12, the yarn portion 18a discharged outside the tank 12 cannot rotate integrally with the tank 12, and rotates slower than the rotation of the tank 12. As a result, the yarn portion 18a starts to be wound around the bobbin 25 arranged on the central axis K of the tank 12. This enables the yarn portion 18a discharged into the tank 12 to be used as a rewind starting point, and the rewinding into the bobbin 25 to be started.

Thereafter, when all the yarn forming the yarn cake 28 is rewound to the bobbin 25 as shown in fig. 11, the control section 51 gives a bobbin driving signal to the bobbin driving section 55 to move the bobbin supporting section 13 downward. This ends the rewind step S3.

By the above operation, the bobbin 25 around which the cop 29 is wound is obtained. The bobbin 25 around which the cop 29 is wound is removed from the bobbin mounting portion 27. Thereafter, the empty bobbin 25 is mounted on the bobbin mounting portion 27, and the same operation as described above is performed.

< effects of the embodiment >

In the embodiment of the present invention, the centrifugal type spinning machine 1 is provided with the air nozzle 31. In the centrifugal spinning method, the yarn portion 18a, which becomes a rewinding starting point portion to rewind the yarn to the bobbin 25, wound around the region 22a of the inner wall 22 of the tank 12 is discharged to the outside of the tank 12 by blowing the compressed air using the air nozzle 31, and the yarn is rewound to the bobbin 25. This enables the bobbin 25 to be rewound appropriately without using a bobbin having a special structure. Therefore, for example, when a centrifugal spinning machine is newly introduced into an existing spinning factory in which the ring spinning machine has been introduced, the bobbin used for the ring spinning can be used for the centrifugal spun yarn. Therefore, the cost associated with the introduction of the centrifugal spinning machine can be reduced to a low cost. Further, in the conventional technique, since the bobbin is attached to the outside of the yarn guide tube, it is necessary to increase the diameter of the upper opening of the can and the diameter of the bearing supported, and there is a problem that the bearing is deteriorated in terms of life, power, and cost.

In addition, according to the embodiment of the present invention, the yarn cake 28 formed on the inner wall 22 of the tank 12 is not a contact type in which some kind of member is physically contacted, but a non-contact type using the blow of the compressed air. Therefore, the winding back to the bobbin 25 can be performed without causing various problems that may be caused by the contact system. Further, as a possible problem of the contact method, for example, there is a reduction in durability due to wear of parts, or a reduction in quality of a spun yarn due to mixing of wear debris.

Further, according to the embodiment of the present invention, compared to the technique described in patent document 1, there is an advantage that, when yarn breakage occurs in the middle of the cake forming step S2, the time for coping with the abnormal spindle can be secured. The reason for this is as follows.

First, in the technique described in patent document 1, when a yarn cake is formed by winding a yarn around the inner wall of a can, yarn is continuously spun from the lower end of a yarn guide tube, and yarn cutting is performed by projecting one end of a bobbin in the axial direction and catching the yarn in a notch portion of the bobbin. Therefore, when the one end of the bobbin is not projected at a timing when a predetermined amount of yarn is wound around the inner wall of the tank (hereinafter, referred to as "full bobbin timing"), an excessive amount of yarn exceeding the predetermined amount is wound, and the inner diameter of the yarn package is reduced. When the bobbin is protruded, the bobbin may come into contact with the yarn cake rotating together with the can. As a result, various problems may occur, such as breakage of the bobbin and improper rewinding into the bobbin. Therefore, in the technique described in patent document 1, when the yarn is fully wound, the bobbin needs to be protruded while the yarn is continuously spun, and rewinding to the bobbin needs to be started.

In contrast, in the embodiment of the present invention, the control unit 51 is configured to control the draft device 10 to cut the yarn at the stage when the predetermined amount of the yarn 18 is wound around the inner wall 22 of the tank 12, and thereafter, as long as the compressed air is not ejected from the air nozzle 31, the rewinding to the bobbin 25 is not started. This means that even after a predetermined amount of the yarn 18 is wound around the inner wall 22 of the tank 12, rewinding to the bobbin 25 can be started at an arbitrary timing. On the other hand, in the technique described in patent document 1, the timing of starting rewinding into the bobbin is not arbitrary, but is limited to a narrow range.

Therefore, according to the embodiment of the present invention, even when a yarn breakage occurs in the middle of the cake forming step S2, for example, immediately before the full bobbin time at the time when the yarn breakage occurs, the rewinding to the bobbin 25 can be waited until the end of the response to the abnormal spindle. Specifically, the ejection timing of the compressed air can be delayed by the time required to cope with the abnormal spindle. Therefore, even when yarn breakage occurs immediately before the full bobbin count, it is possible to secure a time for coping with yarn breakage. In this regard, in the technique described in patent document 1, since the rewinding to the bobbin needs to be started at substantially the same time as the full bobbin timing, if the yarn breakage occurs immediately before the full bobbin timing, it is not possible to secure a time for coping with the yarn breakage.

Incidentally, the time for coping with the yarn breakage is, for example, the following time.

When a yarn break occurs in the middle of the cake forming step S2, the yarn sensor 19 outputs a yarn break generation signal, and the control unit 51 receives the yarn break generation signal and specifies the spindle to which the yarn sensor 19 that outputs the yarn break generation signal belongs. Then, the control unit 51 moves a self-propelled truck (not shown) provided in the centrifugal spinning machine 1 to the spindle position determined as described above. The truck includes a lifter that raises the air nozzles provided in the respective spindles so that the spindles that have broken yarns start rewinding on the bobbin 25 at the same timing as the other spindles. Therefore, when a yarn breakage occurs in any one of the spindles, a time for moving the truck and a time for operating the lifter are required each time, and these times become a time for coping with the yarn breakage.

In the embodiment of the present invention, the spinning conditions are changed during the yarn cutting so that the yarn strength of the yarn portion 18a serving as the backrush starting point portion is higher than the yarn strength of the yarn portion forming the cake 28. Thus, compared to the case where the spinning conditions are not changed during yarn cutting, yarn breakage is less likely to occur in the yarn portion 18a discharged to the outside of the tank 12 by the compressed air blow. Therefore, the yarn portion 18a discharged to the outside of the tank 12 can be more reliably wound around the bobbin 25. As a result, the risk of failure in rewinding the bobbin 25 can be reduced.

However, when a yarn break occurs in the middle of the formation of the yarn cake, the formation of the yarn cake is actually completed at a stage when the end portion of the yarn 18 generated by the yarn break is wound around the inner wall 22 of the can 12. Therefore, the position of the end of the yarn 18 where the yarn is wound due to the yarn breakage (hereinafter referred to as "yarn breakage position") is displaced upward from the position where the yarn cake formation is normally finished and the yarn cutting is performed. In this case, the distance from the yarn cutting position to the opening 23 of the can 12 becomes long. Therefore, in the configuration in which the compressed air is blown using the air nozzle 31, the end of the yarn 18 having broken yarn is not easily discharged to the outside of the tank 12.

< second embodiment >

Here, in the second embodiment of the present invention, a configuration as shown in fig. 12 is adopted.

In fig. 12, an air nozzle 61 is attached to the bobbin base 26 of the bobbin support portion 13. The air nozzle 61 can be moved up and down by an unshown lifting unit in accordance with the height of the yarn cutting position. The air nozzle 61 is provided with a plurality of discharge ports 62. The plurality of discharge ports 62 discharge compressed air, respectively. The plurality of discharge ports 62 are provided at vertically displaced positions in the central axis direction of the tank 12. The compressed air ejected from each ejection port 62 is blown obliquely toward the opening 23 side of the tank 12 toward the inner wall 22 of the tank 12. The air nozzle 61 is arranged such that the compressed air ejected from the ejection port 62 located on the far side from the opening 23 of the tank 12 among the ejection ports 62 is blown to the end of the yarn 18 caused by the yarn breakage, that is, the yarn breakage position. The position of yarn breakage of the yarn cake 28 corresponds to the end of the yarn cake 28 on the side of the opening 23 when viewed from the direction of the center axis of the can 12. The blowing angle of the compressed air to be blown out to the inner wall 22 of the tank 12 is preferably 20 degrees or more and 60 degrees or less, and more preferably 30 degrees or more and 45 degrees or less, as in the above-described embodiment. The blowing direction in which the compressed air is blown in the circumferential direction of the tank 12 may be set to, for example, a direction parallel to a normal direction perpendicular to the circumferential direction of the tank 12. This point is also the same as the first embodiment.

In the second embodiment of the present invention, when a yarn break occurs during the formation of the yarn cake in the yarn cake forming step S2, the control unit 51 specifies the position of the yarn break in the yarn cake based on the yarn break generation signal output from the yarn sensor 19. Thereafter, in the rewinding step S3, the control unit 51 arranges the bobbin 25 and the air nozzle 61 in the tank 12 through the opening 23 by the ascent of the bobbin base 26, and then blows compressed air to the part of the inner wall 22 of the tank 12 from the previously determined yarn breakage position to the opening 23 using the air nozzle 61.

The compressed air using the air nozzle 61 is blown by the control unit 51 outputting a nozzle drive signal to the nozzle drive unit 56. Thus, compressed air is blown to a plurality of positions in the central axis direction of the tank 12 at positions displaced from the yarn cutting position to the inner wall 22 of the tank 12 from the opening 23. At this time, the compressed air ejected from the uppermost ejection port 62 is blown toward the yarn breakage position, whereby the yarn can be peeled from the inner wall 22 of the tank 12 at the yarn breakage position. The compressed air blown from the discharge port 62 located lower than the uppermost position causes the yarn peeled from the inner wall 22 of the tank 12 to move toward the opening 23 and to be discharged outside the tank 12. As a result, even when yarn breakage occurs in the middle of the formation of the yarn cake, the yarn can be rewound from the inner wall 22 of the tank 12 to the bobbin 25 by the blowing of the compressed air by the air nozzle 61.

The air nozzle 61 is not limited to the case where yarn breakage occurs during formation of a yarn cake, and may be applied to the rewinding after the formation of a yarn cake is normally completed. In this case, a nozzle position adjusting mechanism for adjusting the position of the air nozzle 61 in the central axis direction of the tank 12 may be provided to prevent the compressed air discharged from the plurality of discharge ports 62 from being directly blown to the cake 28, and the driving of the nozzle position adjusting mechanism may be controlled by the control unit 51. Further, the control unit 51 may specify the yarn breakage position based on the timing at which the yarn breakage occurrence signal is output from the yarn sensor 19, and the control unit 51 may control the driving of the nozzle position adjustment mechanism based on the specified yarn breakage position to adjust the position of the air nozzle 61.

The nozzle position adjustment mechanism is not limited to the configuration including the air nozzle 61, and may be applied to the configuration including the air nozzle 31 described above. With this configuration, when the end position of the yarn package 28 is changed in the direction of the central axis of the tank 12, the air nozzle 31 can be disposed at an appropriate position corresponding to the changed end position of the yarn package 28.

< modification example et al >

The technical scope of the present invention is not limited to the above-described embodiments, and includes various modifications and improvements within a scope in which specific effects obtained by the components and combinations of the present invention can be derived.

For example, in the above-described embodiment, as the structure of the centrifugal spinning machine 1, an example in which the yarn guide tube 11 is arranged relatively upward and the bobbin 25 is arranged relatively downward is shown, but the present invention is not limited to this, and the yarn guide tube 11 may be arranged relatively downward and the bobbin 25 may be arranged relatively upward. The center axis K (see fig. 1) of the tank 12 does not necessarily have to be parallel to the vertical direction. For example, the center axis K of the tank 12 may be disposed obliquely to the vertical direction, or may be disposed perpendicular to the vertical direction.

In the above embodiment, the air nozzle 31 is attached to the bobbin base 26 of the bobbin support portion 13, and the air nozzle 31 moves in the vertical direction integrally with the bobbin support portion 13, but the present invention is not limited to this. For example, the air nozzle 31 may be configured to be movable in the vertical direction independently from the bobbin supporting portion 13. This point is also the same for the air nozzle 61 described as the second embodiment.

In the above embodiment, as shown in fig. 6, as the operation of the yarn guide tube 11 for forming the yarn cake 28, the yarn guide tube 11 is continuously lowered until the yarn guide tube 11 reaches the Pn position from the Pm-1 position through the Pm position, but the present invention is not limited to this. For example, when the yarn guide tube 11 reaches the Pm position from the Pm-1 position, the lowering operation of the yarn guide tube 11 may be temporarily stopped, and thereafter, the yarn guide tube 11 may be lowered to the Pn position. In fig. 6, the lowering speed of the yarn guide tube 11 when the yarn guide tube is lowered from the Pm-1 position to the Pm position and the lowering speed of the yarn guide tube 11 when the yarn guide tube is lowered from the Pm position to the Pn position are the same speed, but the present invention is not limited thereto, and the yarn guide tube 11 may be lowered at different speeds. Specifically, the lowering speed of the yarn guide tube 11 when the yarn guide tube is lowered from the Pm position to the Pn position may be set faster or slower than the lowering speed of the yarn guide tube 11 when the yarn guide tube is lowered from the Pm-1 position to the Pm position.

In the above embodiment, the bobbin 25 which can be rotated for ring spinning is used, but the present invention can be implemented using other bobbins.

In the above embodiment, the yarn portion 18a to be the rewinding start point portion to the bobbin 25 is wound in the region 22a on the opening 23 side of the terminal end 28b of the yarn cake 28 by moving the yarn guide tube 11 downward by the predetermined amount Lh after the yarn guide tube 11 reaches the Pm position, but the yarn in the yarn guide tube 11 may be wound in the region 22a in a multi-layer amount after yarn cutting depending on the yarn type to be the yarn portion 18a to be the rewinding start point portion. In this case, after the yarn cutting, the yarn guide tube 11 may be moved downward by a predetermined amount from the Pm position, and the process may be shifted to a step of discharging the yarn portion 18a to the outside of the tank by compressed air.

Further, a yarn cake forming step different from the yarn cake forming step shown in fig. 6 may be used (for example, a step disclosed in japanese patent laid-open No. 4-308227).

Further, the opening of the can may be an upper side.

Claims

1. A centrifugal spinning process, comprising the steps of:

rotating a can having an opening and winding a yarn drawn to a predetermined fineness around an inner wall of the can to form a yarn cake;

disposing a bobbin in the can through the opening;

blowing compressed air to a region of the inner wall of the tank on the opening side of the end of the yarn cake on the opening side, thereby discharging a yarn part existing in the region to the outside of the tank; and

the yarn forming the yarn cake is rewound from the inner wall of the tank toward the bobbin with the yarn portion discharged outside the tank as a rewind starting point portion.

2. A centrifugal spinning process according to claim 1,

rotating the canister at a first rotational speed when the yarn cake is formed, and rotating the canister at a second rotational speed lower than the first rotational speed when the compressed air is blown.

3. A centrifugal spinning method according to claim 1 or 2,

the compressed air is blown at an angle of 20 degrees or more and 60 degrees or less toward the opening portion side with respect to the inner wall of the tank.

4. A centrifugal spinning method according to claim 1 or 2,

comprises the following steps: the yarn portion serving as the rewind starting portion is wound around an area of the inner wall of the can closer to the opening than an end portion of the yarn package on the winding end side.

5. A centrifugal spinning method according to claim 1 or 2,

the yarn strength of the yarn portion which becomes the backrush starting point portion is greater than the yarn strength of the yarn portion which forms the yarn cake.

6. A centrifugal spinning method according to claim 1 or 2,

when a yarn break occurs during the formation of the yarn cake, compressed air is blown to a plurality of positions in the direction of the central axis of the tank at positions displaced from each other with respect to the inner wall of the tank from the yarn portion to the opening portion, the inner wall being formed by winding the yarn portion around the region from the yarn break position to the yarn cake.

7. A centrifugal spinning frame is provided with:

a yarn guide tube;

a yarn drawn to a predetermined fineness is wound around an inner wall of the can by operation of the yarn guide tube and the can to form a yarn cake, and the yarn forming the yarn cake is rewound from the inner wall of the can to the bobbin,

the centrifugal spinning machine is characterized in that,