Description:TECHNICAL FIELD
[0001] The present disclosure relates to a yarn winding apparatus.

BACKGROUND ART
[0002] A yarn winding apparatus is known, which winds yarn unwound from a yarn feeding bobbin, so as to form a package. In this type of yarn winding apparatus, if yarn breakage occurs between the yarn feeding bobbin and the package, a suction mouth sucks and catches the yarn on the package side so as to guide it to a yarn splicing device, which splices yarn.
[0003] In a yarn winding apparatus disclosed in WO2015/029275, an upper yarn catching and guiding device moves from a standby position to a catching position on the package side, so as to suck and catch upper yarn that is yarn on the package side. After that, the upper yarn catching and guiding device returns to the standby position, so as to guide the upper yarn to the yarn splicing device.

SUMMARY OF INVENTION
TECHNICAL PROBLEM
[0004] If yarn breakage occurs between the yarn feeding bobbin and the package, there is a possibility that a yarn end on the package side may underlie the yarn wound on the package. The phenomenon that the yarn end on the package side underlies the yarn wound on the package as described above is referred to as underlying yarn. If the yarn is wound on the package in the state where the underlying yarn has occurred, quality of the package is lowered.
[0005] It is an object of the present invention to reduce a chance of winding the yarn on the package in the state where the underlying yarn has occurred, in the yarn winding apparatus, so as to improve quality of the package.

TECHNICAL SOLUTION
[0006] Hereinafter, a plurality of embodiments are described as means for solving the problem. These embodiments can be arbitrarily combined as necessary.
[0007] A yarn winding apparatus of the present disclosure includes a yarn feeding unit, a winding unit, a yarn splicing device, a first catching unit, a second catching unit, a detection unit, and a control section. The yarn feeding unit feeds yarn. The winding unit winds the yarn fed from the yarn feeding unit so as to form a package. The yarn splicing device splices yarn on the package side and yarn on the yarn feeding unit side. The first catching unit catches a yarn end on the package side so as to guide the yarn to the yarn splicing device. The second catching unit catches a yarn end on the yarn feeding unit side so as to guide the yarn to the yarn splicing device. The detection unit detects the yarn caught by the first catching unit. The control section performs a first control and a second control. In the first control, a first rotation control is performed, including rotating the package in a yarn unwinding direction (rotating backward), and in this state the first catching unit is allowed to catch the yarn. After that, if the yarn is detected by the detection unit, a second rotation control is performed in which the package is further rotated in the yarn unwinding direction. In the second control, if the yarn is not detected by the detection unit after the first control, first abnormality is informed.
[0008] This yarn winding apparatus informs abnormality if there is a possibility that the underlying yarn has occurred, so as to reduce a chance of winding the yarn on the package in the state where the underlying yarn has occurred. In this way, quality of the package is improved.
[0009] The control section may further perform a catching control. In the catching control, the package is rotated at a first speed in the yarn unwinding direction, and in this state the first catching unit is allowed to catch the yarn, and the detection unit is allowed to detect the yarn. The first control is a control that is performed if the yarn is not detected as a result of the catching control, and rotation speed of the package in the second rotation control may be a second speed higher than the first speed.
[0010] This yarn winding apparatus performs the first control if the first catching unit fails in catching the yarn in the catching control. In the second rotation control, the package is rotated backward at a speed higher than the rotation speed in the catching control. In this way, accuracy of detecting occurrence of the underlying yarn is improved.
[0011] The control section may rotate the package at the first speed in the yarn unwinding direction, if the yarn is detected as a result of the catching control.
[0012] In this yarn winding apparatus, if the first catching unit has succeeded in catching the yarn in the catching control, the package is rotated in the yarn unwinding direction maintaining the first speed. In this way, amount of the yarn sucked by the first catching unit can be reduced.
[0013] The second speed may be four times or more and nine times or less the first speed.
[0014] The control section may change the second speed on the basis of diameter of the package.
[0015] In this yarn winding apparatus, the package can be rotated at an appropriate speed regardless of the diameter of the package.
[0016] As the first rotation control, the control section may allow the package to rotate at a third speed higher than the first speed in a yarn winding direction, and then allow the package to rotate at the first speed in the yarn unwinding direction.
[0017] In this yarn winding apparatus, it is possible to efficiently catch the yarn on the package side.
[0018] As the first rotation control, the control section may allow the package to perform an alternating rotation motion, in which forward rotation in the yarn winding direction and backward rotation in the yarn unwinding direction are alternately performed.
[0019] In this yarn winding apparatus, it is possible to efficiently catch the yarn on the package side.
[0020] The control section may allow the first catching unit to separate from the package before performing the second rotation control.
[0021] In this yarn winding apparatus, suction by the first catching unit does not act on the yarn wound on the package, and hence the underlying yarn can be easily wound on the package when the package is rotated backward. In this way, accuracy of detecting occurrence of the underlying yarn is improved.
[0022] The detection unit may include a first detection unit and a second detection unit. The first detection unit detects the yarn inside the first catching unit. The second detection unit detects the yarn in a yarn travel path between the yarn feeding unit and the winding unit. The control section may allow the first detection unit to detect the yarn in the first control, and may allow the second detection unit to detect the yarn in the second control.
[0023] If the yarn is not detected by the detection unit in the first control, the control section may inform second abnormality.
[0024] In this yarn winding apparatus, it is possible to inform abnormality, while discriminating between the case where the yarn cannot be caught in the first control (the case of failing in catching), and the case where the yarn cannot be caught in the second control (the case where underlying yarn may have occurred).

ADVANTAGEOUS EFFECTS
[0025] The yarn winding apparatus according to the present invention can improve quality of the package.

BRIEF DESCRIPTION OF DRAWINGS
[0026] Fig. 1 is a diagram illustrating a structure of an automatic winder.
Fig. 2 is a diagram illustrating a structure of a yarn winding apparatus.
Fig. 3 is a flowchart illustrating a flow of processing for forming a package.
Fig. 4 is a flowchart illustrating a flow of processing of a first control and a second control.
Fig. 5 is a diagram illustrating the package on which underlying yarn has occurred.
Fig. 6 is a timing chart of a first rotation control and a second rotation control.
Fig. 7 is a timing chart of the first rotation control and the second rotation control of a variation H.
Fig. 8 is a flowchart illustrating a flow of processing of the first control and the second control of a variation K.
Fig. 9 is a flowchart illustrating a flow of processing of the first control and the second control of a variation L.
Fig. 10 is a flowchart illustrating a flow of processing of the first control and the second control of a variation M.

DESCRIPTION OF EMBODIMENTS
[0027] 1. First Embodiment
(1) Structure of Automatic Winder
Hereinafter, a first embodiment of the present invention is described in detail. First, a structure of an automatic winder 1 according to the first embodiment is described with reference to Fig. 1. Fig. 1 is a diagram illustrating a structure of the automatic winder 1.
[0028] The automatic winder 1 includes a plurality of yarn winding apparatuses 10 that are arranged side by side. Each yarn winding apparatus 10 unwinds yarn 14 from a yarn feeding bobbin 16, and forms a package 22 while traversing the yarn 14. A structure and operations of the yarn winding apparatus 10 will be described later in detail.
[0029] The automatic winder 1 includes a machine control device 12. The machine control device 12 can communicate with each yarn winding apparatus 10. An operator of the automatic winder 1 appropriately operates the machine control device 12, and can integrally manage the plurality of yarn winding apparatuses 10. The machine control device 12 is equipped with a display 12a, and an input interface 12b. The display 12a displays information related to set contents and/or states of the yarn winding apparatus 10, and the like. When the operator appropriately operates the input interface 12b, setting work for the yarn winding apparatus 10 can be performed.
[0030] The display 12a is a display device such as a liquid crystal display. The input interface 12b is an input device such as input keys or a touch panel. In addition, the display 12a and the touch panel as the input interface 12b may be one unit.
[0031] The automatic winder 1 includes a doffing device 13. When the package 22 becomes a full volume (a state where a defined amount of yarn is wound) in any one of the yarn winding apparatuses 10, the doffing device 13 moves to the yarn winding apparatus 10, so as to detach the full volume package and to set an empty winding bobbin.
[0032] (2) Structure of Yarn Winding Apparatus
Hereinafter, a structure of the yarn winding apparatus 10 according to the first embodiment is described with reference to Fig. 2. As illustrated in Fig. 2, the yarn winding apparatus 10 includes a main body of the yarn winding apparatus 10 having a yarn feeding unit 15 and a winding unit 17, and a unit control section (a control section) 50. The yarn winding apparatus 10 according to the first embodiment is the yarn winding apparatus 10 of a drum type, but the yarn winding apparatus 10 may be a winding apparatus of an arm traverse type or a winding apparatus of a belt traverse type. In addition, the yarn winding apparatus 10 according to the first embodiment is mounted in the automatic winder 1, but the yarn winding apparatus 10 may be mounted in an air spinning machine or an open-end spinning machine, for example.
[0033] The yarn winding apparatus 10 includes the yarn feeding unit 15 in the lower part. In other words, the yarn winding apparatus 10 includes the yarn feeding unit 15 disposed on an upstream side in a traveling direction of the yarn 14 when winding the yarn. The yarn feeding unit 15 feeds the winding unit 17 with the yarn 14 for manufacturing the package 22. Specifically, the yarn feeding unit 15 is a conveyance tray type feeding mechanism, which supports the yarn feeding bobbin 16 placed on a conveyance tray (not shown) at a predetermined position, so as to feed the yarn feeding bobbin 16 to the predetermined position. The yarn feeding unit 15 is not limited to the conveyance tray type feeding mechanism, but may be a magazine type feeding mechanism, for example. Note that the position of the yarn feeding unit 15 is not limited to the lower part.
[0034] The winding unit 17 pulls out the yarn 14 from the yarn feeding bobbin 16 supported by the yarn feeding unit 15. The pulled out yarn 14 is wound to form the package 22 by the winding unit 17.
[0035] The yarn winding apparatus 10 includes the winding unit 17 in the upper part. In other words, the yarn winding apparatus 10 includes the winding unit 17 disposed on a downstream side in the traveling direction of the yarn 14 when winding the yarn. The winding unit 17 includes a cradle 18, and a winding drum 20 as main components. Note that the position of the winding unit 17 is not limited to the upper part.
[0036] The cradle 18 has a pair of rotation support parts (not shown), which sandwich the package 22 at both ends in the length direction, so as to support the package 22 in a rotatable manner about a predetermined axis.
[0037] The winding drum 20 is a cylindrical member that is driven by a first motor 21 to rotate about the axis. The winding drum 20 rotates in the state where the outer periphery of the package 22 is contacted with the winding drum 20, and hence a drive force is applied to the package 22, which is driven to rotate along with the rotation of the winding drum 20.
[0038] In addition, a spiral traverse groove is formed on the side surface of a cylinder of the winding drum 20. During rotation of the winding drum 20, the package 22 is driven to rotate, and the yarn 14 unwound from the yarn feeding bobbin 16 is traversed by the traverse groove on the surface of the package 22 within a certain width. In this way, the yarn 14 unwound and fed from the yarn feeding bobbin 16 is wound on the surface of the package 22 while being traversed. As a result, the package 22 is formed, which has a certain winding width.
[0039] The yarn winding apparatus 10 includes a yarn unwinding assist device 25, a tension applying device 27, a yarn splicing device 38, and a clearer (second detection unit) 40, which are disposed in order from the yarn feeding unit 15 to the winding unit 17.
[0040] The yarn unwinding assist device 25 restricts warping (balloon) of the unwound yarn 14, so as to stabilize unwinding tension. The yarn unwinding assist device 25 has a movable cylindrical body 26. The yarn unwinding assist device 25 allows the movable cylindrical body 26 covering a core tube of the yarn feeding bobbin 16 to move downward in synchronization with unwinding of the yarn 14 from the yarn feeding bobbin 16, so as to assist unwinding of the yarn 14 from the yarn feeding bobbin 16. The movable cylindrical body 26 contacts the balloon formed above the yarn feeding bobbin 16 due to rotation of the yarn 14 unwound from the yarn feeding bobbin 16 and a centrifugal force, so as to apply an appropriate tension to the balloon, and thus assists unwinding of the yarn 14.
[0041] The tension applying device 27 applies a predetermined tension to the traveling yarn 14. As the tension applying device 27, for example, it is possible to use a gate type, in which a movable comb tooth member is disposed against a fixed comb tooth member. The movable comb tooth member is configured to be engaged or released from the fixed comb tooth member. By allowing the yarn 14 to travel meandering between the comb tooth members in the engaged state, the yarn 14 to be wound is applied with a certain tension so that quality of the package 22 can be improved. Note that the tension applying device 27 is not limited to the gate type described above, but may be a disc type, for example.
[0042] If the clearer 40 detects a yarn defect and cuts the yarn, or if yarn breakage occurs during unwinding from the yarn feeding bobbin 16, the yarn splicing device 38 splices the yarn 14 on the side of the yarn feeding bobbin 16 and the yarn 14 on the side of the package 22. The yarn splicing device 38 is a splicer device that twists the yarn ends together using swirling air flow generated by compressed air, for example.
[0043] The clearer 40 monitors a state of the yarn 14 traveling in the yarn travel path between the yarn feeding unit 15 and the winding unit 17, and detects presence or absence of a yarn defect on the basis of the monitored information. The clearer 40 detects, for example, thickness abnormality of the yarn 14 and/or foreign object included in the yarn 14, as a yarn defect. In addition, the clearer 40 also detects presence or absence of the yarn 14 in the travel path.
[0044] Specifically, the clearer 40 has a slit through which the yarn 14 passes, which is disposed in the yarn travel path for the yarn 14, and monitors the yarn 14 passing through the slit with a not-shown sensor. For instance, if the clearer 40 detects that amount of light detected by an optical sensor is normal within a predetermined range, it outputs a yarn presence signal to the unit control section 50.
[0045] In addition, for example, if the clearer 40 detects that the amount of light detected by the optical sensor is more excessive than the predetermined range (the yarn 14 is too thin, or a yarn breakage has occurred), or is too little (the yarn 14 is too thick), it may output a yarn defect detection signal to the unit control section 50. Note that the sensor is not limited to the optical sensor but may be a capacitance sensor.
[0046] A cutter 41 for cutting the yarn 14 is disposed in a vicinity of the clearer 40. The cutter 41 is driven to work by the clearer 40.
[0047] The yarn winding apparatus 10 includes a first catching unit 30 on the downstream side of the yarn splicing device 38 in the traveling direction of the yarn 14 when winding the yarn. The first catching unit 30 is a device that sucks and catches a yarn end of the yarn 14 on the side of the package 22 when the yarn 14 becomes disconnected. The first catching unit 30 includes a shaft part 31, a pipe part 32, and a sucking and catching unit 33. The pipe part 32 and the sucking and catching unit 33 are capable of turning (moving) about the shaft part 31, from a standby position on the side of the yarn feeding unit 15 (illustrated by a solid line in Fig. 2) to a catching position on the side of the winding unit 17 (illustrated by a broken line in Fig. 2). Note that in the following description, the yarn 14 on the side of the package 22 may be referred to as upper yarn, and a yarn end of the upper yarn may be referred to as an upper yarn end.
[0048] In addition, the first catching unit 30 is connected to a suction device 19 on the side of the shaft part 31 of the pipe part 32, and a suction air flow can be created at the sucking and catching unit 33 (specifically, at a suction inlet of its distal end). As the suction device 19, for example, a system is adopted which includes a duct 191 extending in the direction where the yarn winding apparatuses 10 are arranged, on the back side of each yarn winding apparatus 10, having one end connected to the shaft part 31, and a suction source 193 connected to the other end of the duct 191, so as to create a predetermined negative pressure in the duct 191. The suction source 193 is a blower device, for example. The sucking and catching unit 33 is formed in an elongated shape so as to cover the winding width of the package 22. In this way, the suction air flow can act over the entire winding width of the outer periphery surface of the package 22.
[0049] With the structure described above, the first catching unit 30 in the catching position can suck and catch the yarn end on the side of the package 22 into the pipe part 32, using the suction air flow created at the sucking and catching unit 33. In addition, when the first catching unit 30 returns to the standby position, it can guide the caught yarn 14 on the side of the package 22 to the yarn splicing device 38.
[0050] In this embodiment, the first catching unit 30 includes a shutter (not shown) at a connection part between the pipe part 32 and the duct 191. The shutter opens and closes a flow path from the pipe part 32 to the duct 191. Specifically, if the shutter closes the flow path, the suction air flow cannot be created at the sucking and catching unit 33. In contrast, if the shutter opens the flow path, the suction air flow is created at the sucking and catching unit 33.
[0051] The first catching unit 30 is connected to an output shaft of a second motor 39. The second motor 39 is electrically connected to the unit control section 50. The unit control section 50 controls the second motor 39 so that the second motor 39 can start or stop rotating, or can change its rotation direction.
[0052] In addition, the yarn winding apparatus 10 includes a yarn detection sensor (first detection unit) 43. The yarn detection sensor 43 is disposed in a vicinity of the winding unit 17. The yarn detection sensor 43 detects whether or not the first catching unit 30 has caught the yarn 14. Specifically, the yarn detection sensor 43 detects whether or not there is the yarn 14 (the yarn end) inside the pipe part 32. The yarn detection sensor 43 is electrically connected to the unit control section 50. The yarn detection sensor 43 is constituted as a known optical sensor, for example, and has a light emitting unit and a light receiving unit that are not shown. The pipe part 32 is partially constituted of a transparent member that can transmit light. When the first catching unit 30 is in an upper yarn catching position (illustrated by the broken line in Fig. 2), the light emitting unit of the yarn detection sensor 43 can emit light to the inside of the pipe part 32 through the transparent member. If there is the yarn 14 inside the pipe part 32, the light receiving unit of the yarn detection sensor 43 can receive the light reflected by the yarn 14. If the yarn detection sensor 43 detects that there is the yarn 14 (the yarn end) inside the pipe part 32, it outputs a yarn detection signal to the unit control section 50.
[0053] The yarn winding apparatus 10 includes a second catching unit 34 disposed on the upstream side of the yarn splicing device 38 in the traveling direction of the yarn 14 when winding the yarn. Similarly to the first catching unit 30 described above, the second catching unit 34 includes a shaft part 35, a pipe part 36, and a sucking and catching unit 37. Similarly to the sucking and catching unit 33 of the first catching unit 30, the sucking and catching unit 37 is capable of turning about the shaft part 35, and can create a suction air flow by suction power. With this structure, the second catching unit 34 can catch the yarn end of the yarn 14 on the side of the yarn feeding unit 15 using the suction air flow, and can guide the caught yarn 14 on the side of the yarn feeding unit 15 to the yarn splicing device 38. Note that in the following description, the yarn 14 on the side of the yarn feeding unit 15 may be referred to as lower yarn, and a yarn end of the lower yarn may be referred to as a lower yarn end.
[0054] Note that similarly to the first catching unit 30, the second catching unit 34 may have a shutter at a connection part between the pipe part 36 and the duct 191, for example, so as to control whether or not to create the suction air flow described above.
[0055] (3) Flow of Package Forming Process
Next, with reference to Figs. 2 to 4, an operation of the yarn winding apparatus 10 in a winding step is described. Fig. 3 is a flowchart illustrating a flow of processing for forming the package 22 in the yarn winding apparatus 10. Fig. 4 is a flowchart illustrating a flow of processing of the first control and the second control. Note that the flowcharts illustrated in Figs. 3 and 4 are merely examples, which may be appropriately modified as long as no contradiction occurs. For instance, another step that is not shown may be added before or after each step, or the order of the steps may be changed as long as no contradiction occurs. Note that in the following description, a rotation of the package 22 in the winding direction of the yarn 14 is referred to as a forward rotation, while a rotation in the yarn unwinding direction is referred to as a backward rotation.
[0056] When performing the winding step for winding the yarn 14 on the package 22, the unit control section 50 determines whether or not disconnection of the yarn 14 has occurred in the yarn travel path from the yarn feeding unit 15 to the winding unit 17 (Step S1). In this embodiment, the unit control section 50 determines whether or not disconnection of the yarn 14 has occurred, on the basis of whether or not the yarn presence signal indicating that there is the yarn 14 is input from the clearer 40. Causes of disconnection of the yarn 14 include, for example, the case where the clearer 40 detects a yarn defect and cuts the yarn 14 with the cutter 41, or the case where the yarn 14 is broken by a large tension force that happens by chance. Alternatively, it may be possible to determine whether or not disconnection of the yarn 14 has occurred, on the basis of a cut signal when the cutter 41 cuts the yarn 14. When disconnection of the yarn 14 occurs in the yarn winding apparatus 10, the upper yarn end of the disconnected yarn 14 is wound on the package 22 that inertially rotates.
[0057] If it is determined that disconnection of the yarn 14 has not occurred (No in Step S1), the unit control section 50 controls to rotate the package 22 at a predetermined winding speed (the rotation speed of the package 22 when the yarn 14 is wound) in the forward direction (Step S5). In this way, the yarn 14 is wound so that the package 22 is formed.
[0058] In contrast, if it is determined that disconnection of the yarn 14 has occurred (Yes in Step S1), the unit control section 50 performs catching control of the upper yarn end using the first catching unit 30 (Step S2).
[0059] The operation of the catching control (Step S2) is described in detail.
The unit control section 50 controls the first motor 21 to stop rotation of the package 22. In addition, the unit control section 50 sends a drive signal to the second motor 39, so as to perform control for turning the pipe part 32 of the first catching unit 30 upward. As a result, the sucking and catching unit 33 reaches the upper yarn catching position illustrated by the broken line in Fig. 2.
[0060] When the sucking and catching unit 33 reaches the upper yarn catching position, the unit control section 50 sends a signal to the first motor 21, so as to allow the package 22 to rotate backward. The unit control section 50 controls the rotation speed so that the package 22 rotate backward at a first speed. The first speed is preferably 100 rpm or more and 150 rpm or less. The unit control section 50 allows the package 22 to rotate backward by a predetermined rotation amount, in the state where the pipe part 32 is moved to the upper yarn catching position in an upper position.
[0061] In addition, the unit control section 50 opens the shutter disposed in the path connecting the pipe part 32 and the duct 191. In this way, the sucking and catching unit 33 can allow the suction air flow to act on the surface of the package 22, at the position substantially facing the surface of the package 22 with a predetermined interval therebetween. In the state where the sucking and catching unit 33 allows the suction air flow to act on the surface of the package 22, the package 22 rotate backward, and thus unwinding of the upper yarn from the package 22, as well as sucking of the upper yarn end by the sucking and catching unit 33 is promoted. When the upper yarn end existing on the surface of the package 22 passes the part facing the sucking and catching unit 33, it is sucked into the pipe part 32 by the action of the suction air flow. The unit control section 50 repeats the catching control until reaching a predetermined number of times. The predetermined number of times may be one or more than one.
[0062] The unit control section 50 determines whether or not the first catching unit 30 has succeeded in catching the upper yarn end, on the basis of the yarn detection signal output from the yarn detection sensor 43 (Step S3). When the signal indicating that there is the yarn 14 inside the pipe part 32 is input from the yarn detection sensor 43, the unit control section 50 finishes the process in Step S1 even if it is proceeding.
[0063] If it is determined that the first catching unit 30 has succeeded in catching the upper yarn end (Yes in Step S3), the unit control section 50 controls the yarn splicing device 38 to perform yarn splicing (Step S4).
[0064] Specifically, while continuing the backward rotation of the package 22 at the first speed, the unit control section 50 sends a drive signal to the second motor 39, so that the pipe part 32 turns downward and moves to the standby position illustrated by the solid line in Fig. 2. In this way, the upper yarn caught by the first catching unit 30 is guided to the yarn splicing device 38.
[0065] On the other hand, the lower yarn end of the disconnected yarn 14 is caught by the suction air flow created at the sucking and catching unit 37 of the second catching unit 34. After the lower yarn end is caught, the unit control section 50 controls the pipe part 36 to turn upward and move to the position illustrated by the broken line in Fig. 2. In this way, the lower yarn caught by the second catching unit 34 is guided to the yarn splicing device 38.
[0066] The unit control section 50 controls the yarn splicing device 38 to splice the upper yarn and the lower yarn (Step S4). The unit control section 50 closes the shutter disposed in the path connecting the pipe part 32 and the duct 191, so as to stop the suction air flow at the sucking and catching unit 33.
[0067] After the yarn splicing performed by the yarn splicing device 38, the unit control section 50 sends a drive signal to the first motor 21, so as to rotate the package 22 forward. In this way, the yarn 14 is wound on the package 22 (Step S5).
[0068] If it is determined that the first catching unit 30 has failed in catching the upper yarn end (No in Step S3), the unit control section 50 starts the first control and the second control. In this embodiment, the first control is constituted of Steps S71to S77 in Fig. 4, and the second control is constituted of Steps S78 to S79 in Fig. 4.
[0069] The unit control section 50 temporarily stops the backward rotation of the package 22, and then performs the first rotation control. The first rotation control is a control including allowing the package 22 to rotate backward. Specifically, for example, in the first rotation control, the package 22 is rotated forward, and then a signal is sent to the first motor 21 so that the rotation direction of the package 22 is changed, i.e., the package 22 is rotated backward (Step S71). In this case, the unit control section 50 controls the rotation speed so that the package 22 rotates forward at a third speed. The third speed is higher than the first speed. The third speed is, for example, 4500 rpm or more and 7000 rpm or less. The unit control section 50 controls to rotate the package 22 forward at the third speed for a predetermined time, and then rotate backward the package 22 at the first speed, while trying to catch the upper yarn end with the first catching unit 30. The unit control section 50 repeats trying to catch the upper yarn end, accompanying the high speed forward rotation and the backward rotation of the package 22, until reaching a predetermined number of times. The predetermined number of times may be one or more than one. In this case, there is a possibility that the upper yarn end on the side of the package 22 may underlie the yarn 14 wound on the package 22, i.e., underlying yarn may occur.
[0070] Fig. 5 is a diagram schematically illustrating the package 22 in the state where the underlying yarn has occurred. Due to the high speed forward rotation of the package 22, the yarn 14 wound on the package 22 (the solid line in Fig. 5) is loosened, and the yarn 14 near the upper yarn end (the broken line in Fig. 5) underlies the yarn 14 wound on the package 22.
[0071] Every time when trying once to catch the upper yarn end, the unit control section 50 monitors the signal input from the yarn detection sensor 43 at an appropriate timing. When the signal indicating that there is the yarn 14 inside the pipe part 32 is input from the yarn detection sensor 43, the unit control section 50 finishes the process of Step S71, even if it is proceeding.
[0072] After that, the unit control section 50 determines whether or not the first catching unit 30 has succeeded in catching the upper yarn end, on the basis of the yarn detection signal output from the yarn detection sensor 43 (Step S72).
[0073] After trying a predetermined number of times to catch the upper yarn end, accompanying the high speed forward rotation and the backward rotation of the package 22, if it is determined that the first catching unit 30 has failed in catching the upper yarn end (No in Step S72), the unit control section 50 sends a signal to the first motor 21, so as to stop the high speed forward rotation and backward rotation of the package 22. After that, the unit control section 50 performs the first rotation control again. The first rotation control is a control including allowing the package 22 to rotate backward. Specifically, for example, as the first rotation control, the package 22 is allowed to perform alternating rotation motion in which forward rotation and backward rotation are alternately performed (Step S73).
[0074] In this case, the unit control section 50 first sends a signal to the first motor 21, so as to allow the package 22 to rotate forward. After rotating the package 22 by a predetermined rotation amount, the unit control section 50 sends a signal to the first motor 21, so as to switch the rotation direction of the package 22, so as to allow the package 22 to rotate backward by a predetermined rotation amount. The unit control section 50 allows the package 22 to perform the alternating rotation motion, and tries to catch the upper yarn end with the first catching unit 30. In one alternating rotation motion, the unit control section 50 controls rotation time, rotation speed, and the like of the package 22, so that rotation amount of the backward rotation is larger than rotation amount of the forward rotation. Specifically, the unit control section 50 controls rotation time, rotation speed, and the like of the package 22, so that rotation amount of the backward rotation minus rotation amount of the forward rotation is at least one turn of the package 22. In this way, suction by the first catching unit 30 can act on the entire perimeter of the package 22. In the state where the pipe part 32 is moved to the upper yarn catching position in the upper part, the unit control section 50 allows the package 22 to perform the alternating rotation motion. In the state where the sucking and catching unit 33 allows the suction air flow to act on the surface of the package 22, the package 22 performs the alternating rotation motion, and thus unwinding of the upper yarn from the package 22, as well as sucking of the upper yarn end by the sucking and catching unit 33 is promoted.
[0075] After performing the alternating rotation motion of the package 22 a predetermined number of times, if the first catching unit 30 has not succeeded in catching the upper yarn end, the unit control section 50 temporarily stops rotation of the package 22, and then the alternating rotation motion of the package 22 is performed again, so as to try catching the upper yarn end with the first catching unit 30. The unit control section 50 repeats trying to catch the upper yarn end, accompanying the alternating rotation motion of the package 22 until reaching a predetermined number of times. The predetermined number of times may be one or more than one. In this case, there is a possibility that the upper yarn end on the side of the package 22 may underlie the yarn 14 wound on the package 22, i.e., underlying yarn may occur.
[0076] Every time when trying once to catch the upper yarn end, the unit control section 50 monitors the signal input from the yarn detection sensor 43 at an appropriate timing. When the signal indicating that there is the yarn 14 inside the pipe part 32 is input from the yarn detection sensor 43, the unit control section 50 finishes the process of Step S73, even if it is proceeding.
[0077] After that, the unit control section 50 determines whether or not the first catching unit 30 has succeeded in catching the upper yarn end, on the basis of the yarn detection signal output from the yarn detection sensor 43 (Step S74).
[0078] After trying a predetermined number of times to catch the upper yarn end, accompanying the alternating rotation motion, if it is determined that the first catching unit 30 has failed in catching the upper yarn end (No in Step S74), the unit control section 50 sends a signal to the first motor 21, so as to stop the alternating rotation motion of the package 22.
[0079] The unit control section 50 determines that there is a possibility of having failed in catching the yarn 14, and allows the display 12a to display that abnormality (second abnormality) has occurred, so as to inform the operator (Step S75). The second abnormality is, for example, abnormality indicating that the yarn 14 cannot separate from the surface of the package 22. In other words, it is possible to discriminate from first abnormality described later, and hence the operator can work on the basis of the content of the abnormality. The display 12a displays, for example, an identification name of the yarn winding apparatus 10 that has caused the abnormality, the content of the abnormality (possibility of having failed in catching the yarn). In addition, it may be possible to generate alarm sound to inform the operator of occurrence of the abnormality.
[0080] If it is determined that the first catching unit 30 has succeeded in catching the upper yarn end (Yes in Step S72 or S74), the unit control section 50 allows the pipe part 32 to turn to a predetermined position (illustrated by a dash-dot line in Fig. 2), while continuing the backward rotation of the package 22 (Step S76). In other words, the unit control section 50 allows the sucking and catching unit 33 to move (separate) to a position apart from the package 22 by a predetermined interval. In this case, the yarn detection sensor 43 and the clearer 40 cannot detect the yarn 14 caught by the first catching unit 30.
[0081] After that, while continuing the backward rotation of the package 22, the unit control section 50 sends a signal to the first motor 21, so as to perform a second rotation control in which the package 22 is rotated backward at a second speed higher than the first speed (Step S77). The second speed is a speed four times or more and nine times or less the first speed. If the second speed is low, the yarn 14 may be wound on the package 22 even in the state where the underlying yarn has occurred. In contrast, if the second speed is too high, there is a possibility that the yarn 14 may be wound on the package 22 due to being caught by fluff or the like even if the underlying yarn has not occurred. In addition, a long part of the yarn 14 is sucked by the sucking and catching unit 33, and hence production efficiency will be lowered. Specifically, the second speed is preferably 600 rpm or more and 900 rpm or less, and is more preferably 800 rpm. After a predetermined time has elapsed, while continuing the backward rotation of the package 22 at the first speed, the unit control section 50 allows the pipe part 32 to turn downward, so as to guide the upper yarn to the yarn splicing device 38.
[0082] Here, if the underlying yarn has not occurred, the yarn 14 on the package 22 is unwound by rotating the package 22 backward, and the upper yarn is guided to the yarn splicing device 38 in the state caught by the sucking and catching unit 33. However, if the underlying yarn has occurred, the underlying yarn is caught by the surface of the package 22, and the yarn 14 cannot be unwound. Hence, along with the backward rotation of the package 22, the yarn 14 is wound backward on the package 22 from the point where the underlying yarn has occurred. In this way, the upper yarn caught by the sucking and catching unit 33 is pulled to the side of the package 22, and hence the upper yarn gets out from inside of the sucking and catching unit 33. As a result, the upper yarn is not guided to the yarn splicing device 38.
[0083] After the first control, in the second control, the unit control section 50 determines presence or absence of the yarn 14, on the basis of the yarn presence signal output from the clearer 40 (Step S78). Specifically, if the upper yarn and the lower yarn are guided to the yarn splicing device 38, the yarn 14 exists in the yarn travel path between the yarn feeding unit 15 and the winding unit 17, and the clearer 40 outputs the yarn presence signal to the unit control section 50. In contrast, if the upper yarn and the lower yarn are not guided to the yarn splicing device 38, the clearer 40 does not output the yarn presence signal.
[0084] If it is determined that there is the yarn 14 (Yes in Step S78), the unit control section 50 finishes the first control and the second control, and allows the yarn splicing device 38 to perform yarn splicing (Step S4).
[0085] If it is determined that there is not the yarn 14 (No in Step S78), the unit control section 50 determines that there is a possibility that the underlying yarn has occurred, and allows the display 12a to display that abnormality (first abnormality) has occurred, so as to inform the operator (Step S79). The display 12a displays, for example, an identification name of the yarn winding apparatus 10 that has caused the abnormality, the content of the abnormality (possibility of occurrence of the underlying yarn). In addition, it may be possible to generate alarm sound to inform the operator of occurrence of the abnormality.
[0086] For instance, if the yarn winding apparatus 10 causes another abnormality requiring to stop winding of the yarn 14, or if the operator instructs to stop the yarn winding apparatus 10, the unit control section 50 stops the processing (Yes in Step S6). If such the situation does not occur (No in Step S6), the unit control section 50 repeatedly executes Steps S1 to S5 described above until the winding of the yarn 14 is finished.
[0087] (4) Flow of First Rotation Control and Second Rotation Control
Next, with reference to the timing chart illustrated in Fig. 6, an operation of the yarn winding apparatus 10 in the first rotation control and the second rotation control is described. Fig. 6 illustrates an example of a timing chart indicating operations of individual units of the yarn winding apparatus 10, after failing in catching the disconnected yarn 14 during formation of the package 22 so as to start the first rotation control.
[0088] At time point t1, the unit control section 50 allows the pipe part 32 of the first catching unit 30 to turn upward. After that, when the pipe part 32 reaches the upper yarn catching position, the unit control section 50 allows the package 22 to rotate backward at time point t2. In this way, the first catching unit 30 tries to catch the upper yarn end. Note that in the example illustrated in Fig. 6, the package 22 is stopped before time point t2, but the package 22 is not always stopped. Specifically, for example, if the package 22 is performing the high speed forward rotation and the backward rotation in the first rotation control, the package 22 may be rotating forward before time point t2. In addition, for example, if the package 22 is performing the alternating rotation motion in the first rotation control, the package 22 may be rotating forward or may be rotating backward before time point t2.
[0089] At time point t3 after a predetermined time, if the yarn detection sensor 43 detects the yarn 14 (if an OFF signal changes to an ON signal), the unit control section 50 allows the pipe part 32 to turn to the predetermined position (illustrated by the dash-dot line in Fig. 2) at time point t4, so that the sucking and catching unit 33 is apart from the package 22 by a predetermined interval. After that, the unit control section 50 allows the package 22 to rotate backward at the second speed higher than the first speed at time point t5. In this way, the package 22 rotates backward at high speed, in the state where the upper yarn end is caught by the first catching unit 30 at the position apart from the package 22.
[0090] At time point t6 after a predetermined time, while continuing the backward rotation of the package 22, the unit control section 50 changes the rotation speed to the first speed, and allows the pipe part 32 to turn downward, so as to guide the upper yarn to the yarn splicing device 38.
[0091] When the upper yarn and the lower yarn are guided to the yarn splicing device 38, because there is the yarn 14 in the yarn travel path between the yarn feeding unit 15 and the winding unit 17, the clearer 40 outputs the yarn presence signal (the ON signal) to the unit control section 50 at time point t7.
[0092] 2. Features of Embodiment
The yarn winding apparatus 10 of this embodiment includes the yarn feeding unit 15, the winding unit 17, the yarn splicing device 38, the first catching unit 30, the second catching unit 34, the yarn detection sensor 43, the clearer 40, and the unit control section 50. The yarn feeding unit 15 feeds the yarn 14. The winding unit 17 winds the yarn 14 fed from the yarn feeding unit 15 so as to form the package 22. The yarn splicing device 38 splice the yarn 14 on the side of the package 22 and the yarn 14 on the side of the yarn feeding unit 15. The first catching unit 30 catches the yarn end on the package side so as to guide the yarn to the yarn splicing device 38. The second catching unit 34 catches the yarn end on the yarn feeding unit side so as to guide the yarn to the yarn splicing device 38. The yarn detection sensor 43 and the clearer 40 detect the yarn 14 caught by the first catching unit 30. The unit control section 50 performs the first control and the second control. In the first control, the first rotation control is performed which includes rotating the package 22 in the unwinding direction of the yarn 14, and in this state the first catching unit 30 is allowed to catch the yarn 14. After that, if the yarn detection sensor 43 detects the yarn 14, the second rotation control is performed, in which the package 22 is further rotated in the unwinding direction of the yarn 14. In the second control, if the clearer 40 does not detect the yarn 14 after the first control, the first abnormality is informed.
[0093] This yarn winding apparatus 10 informs abnormality if there is a possibility that the underlying yarn has occurred, so as to reduce a chance of winding the yarn 14 on the package 22 in the state where the underlying yarn has occurred. In this way, quality of the package 22 is improved.
[0094] In the yarn winding apparatus 10 of this embodiment, the unit control section 50 further performs the catching control. In the catching control, in the state where the package 22 is rotated at the first speed in the unwinding direction of the yarn 14, the first catching unit 30 is allowed to catch the yarn 14, and then the yarn detection sensor 43 is allowed to detect the yarn 14. The first control is a control that is performed if the yarn 14 is not detected as a result of the catching control, and the rotation speed of the package 22 in the second rotation control is the second speed higher than the first speed.
[0095] This yarn winding apparatus 10 performs the first control if the first catching unit 30 fails in catching the yarn 14 in the catching control. In the second rotation control, the package 22 is rotated backward at a speed higher than the rotation speed in the catching control. In this way, accuracy of detecting occurrence of the underlying yarn is improved.
[0096] In the yarn winding apparatus 10 of this embodiment, if the yarn 14 is detected as a result of the catching control, the unit control section 50 allows the package 22 to rotate at the first speed in the unwinding direction of the yarn 14.
[0097] In this yarn winding apparatus 10, if the first catching unit 30 succeeds in catching the yarn 14 in the catching control, the package 22 is rotated in the unwinding direction of the yarn 14 maintaining the first speed. In this way, amount of the yarn 14 sucked by the first catching unit 30 can be reduced.
[0098] In the yarn winding apparatus 10 of this embodiment, the unit control section 50 performs the first rotation control, in which the package 22 is rotated at the third speed higher than the first speed in the winding direction of the yarn 14, and then the package is rotated at the first speed in the yarn unwinding direction.
[0099] In this yarn winding apparatus 10, the yarn 14 on the side of the package 22 can be caught efficiently.
[0100] In the yarn winding apparatus 10 of this embodiment, the unit control section 50 performs the first rotation control, in which the package 22 performs the alternating rotation motion to alternately perform the forward rotation in the winding direction of the yarn 14 and the backward rotation in the yarn unwinding direction.
[0101] In this yarn winding apparatus 10, the yarn 14 on the side of the package 22 can be caught efficiently.
[0102] In the yarn winding apparatus 10 of this embodiment, the unit control section 50 allows the first catching unit 30 to separate from the package 22 before performing the second rotation control.
[0103] In this yarn winding apparatus 10, sucking by the first catching unit 30 does not act on the yarn 14 wound on the package 22. Hence, when the package 22 is rotated backward, the underlying yarn can be easily wound on the package 22. In this way, accuracy of detecting occurrence of the underlying yarn is improved.
[0104] In the yarn winding apparatus 10 of this embodiment, the unit control section 50 informs the second abnormality if the yarn 14 is not detected by the yarn detection sensor 43 or the clearer 40 in the first control.
[0105] In this yarn winding apparatus 10, the abnormality can be informed, while discriminating between the case where the yarn 14 cannot be caught in the first control (the case where the catching is failed), and the case where the yarn 14 cannot be caught in the second control (the case where there is a possibility that the underlying yarn has occurred).
[0106] 3. Variation
In the following description, only structures different from that of this embodiment are described.
[0107] (1) Variation A
The second speed may be a speed four times or more and nine times or less the first speed.
[0108] (2) Variation B
The unit control section 50 may change the second speed on the basis of diameter of the package 22.
In this yarn winding apparatus 10, the package 22 can be rotated so that the yarn 14 is wound at an appropriate speed regardless of the diameter of the package 22.
[0109] (3) Variation C
In this embodiment, the yarn detection sensor 43 is disposed in a vicinity of the winding unit 17, so as to detect whether or not the first catching unit 30 has caught the upper yarn, on the basis of presence or absence of the yarn 14 inside the pipe part 32. However, the yarn detection sensor 43 may not be disposed. In that case, it may be possible to temporarily move the sucking and catching unit 33 to the standby position in the lower part, and then to detect whether or not the first catching unit 30 has caught the upper yarn, on the basis of the yarn presence signal output from the clearer 40.
[0110] (4) Variation D
In this embodiment, if it is determined in the second control that there is the yarn 14 on the basis of the yarn presence signal output from the clearer 40 (Yes in Step S12), the unit control section 50 allows the yarn splicing device 38 to perform the yarn splicing (Step S4). However, the unit control section 50 may determine presence or absence of the yarn 14 on the basis of the yarn presence signal output from the clearer 40, after allowing the yarn splicing device 38 to perform the yarn splicing.
[0111] (5) Variation E
In this embodiment, if the clearer 40 detects that amount of light detected by the optical sensor is normal within a predetermined range, it outputs the yarn presence signal to the unit control section 50. The unit control section 50 determines whether or not the disconnection of the yarn 14 has occurred, on the basis of whether or not the yarn presence signal indicating that there is the yarn 14 is input from the clearer 40. However, if the clearer 40 detects that there is not the yarn 14, it may output a yarn absence signal to the unit control section 50. The unit control section 50 may determine whether or not the disconnection of the yarn 14 has occurred, on the basis of whether or not the yarn absence signal indicating that there is not the yarn 14 is input from the clearer 40.
[0112] (6) Variation F
In this embodiment, the yarn detection sensor 43 is disposed in a vicinity of the winding unit 17, so as to detect presence or absence of the yarn 14 inside the pipe part 32. However, the yarn detection sensor 43 may be disposed inside the first catching unit 30.
[0113] In this yarn winding apparatus 10, regardless of a position of the first catching unit 30, presence or absence of the yarn 14 inside the pipe part 32 can be always monitored. Therefore, in the second control, it is possible to determine presence or absence of the yarn 14, on the basis of the yarn detection signal output from the yarn detection sensor 43.
[0114] (7) Variation G
The yarn detection sensor 43 may include the light emitting unit and the light receiving unit, which are disposed so as to sandwich the transparent member, and it may be possible to detect that there is the yarn 14 (yarn end) inside the pipe part 32, if the light emitted from the light emitting unit to the inside of the pipe part 32 is not received by the light receiving unit.
[0115] (8) Variation H
In this embodiment, in the first control, the unit control section 50 performs the second rotation control in which, while continuing the backward rotation of the package 22 as the first rotation control, the package 22 is allowed to rotate backward at the second speed higher than the first speed (Step S77, at time point t5). However, the unit control section 50 may temporarily stop the backward rotation of the package 22 before performing the second rotation control, and then perform the second rotation control in which the package 22 is allowed to rotate backward again at the second speed.
[0116] Fig. 7 illustrates an example of the timing chart indicating operations of individual units of the yarn winding apparatus 10, after starting the first rotation control of this variation. Operations from time point t1 through time point t3 are the same as those in this embodiment, and descriptions thereof are omitted.
[0117] At time point t4, the unit control section 50 allows the pipe part 32 to turn to the predetermined position (illustrated by the dash-dot line in Fig. 2), so that the sucking and catching unit 33 is apart from the package 22 by a predetermined interval. In addition, the unit control section 50 stops the package 22. After that, at time point t5, the unit control section 50 allows the package 22 to rotate backward at the second speed higher than the first speed. In this way, in the state where the upper yarn end is caught by the first catching unit 30 at the position apart from the package 22, the package 22 rotates backward at high speed. Operations from time point t6 through time point t7 are the same as those in this embodiment, and descriptions thereof are omitted.
[0118] (9) Variation I
In this embodiment, in the second control, the unit control section 50 determines presence or absence of the yarn 14, on the basis of the yarn presence signal output from the clearer 40 (Step S78). However, the unit control section 50 may determine presence or absence of the yarn 14, on the basis of the yarn detection signal output from the yarn detection sensor 43. In that case, the unit control section 50 may allow the pipe part 32 to turn to the upper yarn catching position (the broken line in Fig. 2), so that the yarn detection sensor 43 detects the yarn 14, after the second rotation control.
[0119] (10) Variation J
In this embodiment, in the second control, the unit control section 50 determines presence or absence of the yarn 14, on the basis of the yarn presence signal output from the clearer 40 (Step S78). However, the unit control section 50 may determine presence or absence of the yarn 14, on the basis of the yarn detection signal output from the yarn detection sensor 43. In that case, the unit control section 50 is not required to allow the sucking and catching unit 33 to move (separate) to a position apart from the package 22 by a predetermined interval.
[0120] In this yarn winding apparatus 10, the unit control section 50 is not required to move the position of the sucking and catching unit 33 in the first control and the second control, and the control can be simplified.
[0121] (11) Variation K
In this embodiment, as the first rotation control, the high speed forward rotation and the backward rotation (Step S71) and the alternating rotation motion (Step S73) are performed. However, as the first rotation control, it may be possible to perform only the high speed forward rotation and the backward rotation. Fig. 8 is a flowchart illustrating a flow of processing of the first control and the second control in this variation. Note that the flowchart illustrated in Fig. 8 is merely an example, which may be appropriately modified unless any contradiction occurs. For instance, before or after each step, not shown another step may be included, or the order of the steps may be arbitrarily changed as long as no contradiction occurs. In this variation, the first control is constituted of Steps S271 to S275 in Fig. 8, and the second control is constituted of Steps S276 to S277 in Fig. 8.
[0122] Step S271 is the same as Step S71 in Fig. 4, and description thereof is omitted.
[0123] After trying to catch the upper yarn end, accompanying the high speed forward rotation and the backward rotation of the package 22, a predetermined number of times, if it is determined that the first catching unit 30 has failed in catching the upper yarn end (No in Step S272), the unit control section 50 sends a signal to the first motor 21, so as to finish the high speed forward rotation and the backward rotation of the package 22.
[0124] The unit control section 50 determines there is a possibility of having failed in catching the yarn 14, and allows the display 12a to display that abnormality (second abnormality) has occurred, so as to inform the operator (Step S273). The display 12a displays, for example, an identification name of the yarn winding apparatus 10 that has caused the abnormality, the content of the abnormality (possibility of having failed in catching the yarn). In addition, it may be possible to generate alarm sound to inform the operator of occurrence of the abnormality.
[0125] If it is determined that the first catching unit 30 has succeeded in catching the upper yarn end (Yes in Step S272), the unit control section 50 allows the pipe part 32 to turn to the predetermined position (illustrated by the dash-dot line in Fig. 2), while continuing the backward rotation of the package 22 (Step S274).
[0126] Steps S275 to S277 are the same as Steps S77 to Step S79 in Fig. 4, and descriptions thereof are omitted.
[0127] (12) Variation L
As the first rotation control, it may be possible to perform only the alternating rotation motion. Fig. 9 is a flowchart illustrating a flow of processing of the first control and the second control in this variation. Note that the flowchart illustrated in Fig. 9 is merely an example, which may be appropriately modified unless any contradiction occurs. For instance, before or after each step, not shown another step may be included, or the order of the steps may be arbitrarily changed as long as no contradiction occurs. In this variation, the first control is constituted of Steps S371 to S375 in Fig. 9, and the second control is constituted of Steps S376 to S377 in Fig. 9.
[0128] The unit control section 50 temporarily stops the backward rotation of the package 22, and then performs the first rotation control. The first rotation control is a control including allowing the package 22 to rotate backward. As the first rotation control, the unit control section 50 allows the package 22 to perform alternating rotation motion in which forward rotation and backward rotation are alternately performed (Step S371). Details of the alternating rotation motion are the same as those of Step S73 in this embodiment, and descriptions thereof are omitted.
[0129] Steps S372 to S377 are the same as Steps S74 to S79 in Fig. 4, and descriptions thereof are omitted.
[0130] (13) Variation M
In this embodiment, as the first rotation control, the high speed forward rotation and the backward rotation (Step S71) including the backward rotation of the package 22, and the alternating rotation motion (Step S73) are performed. However, as the first rotation control, it may be possible to perform only the backward rotation of the package 22. Fig. 10 is a flowchart illustrating a flow of processing of the first control and the second control in this variation. Note that the flowchart illustrated in Fig. 10 is merely an example, which may be appropriately modified unless any contradiction occurs. For instance, before or after each step, not shown another step may be included, or the order of the steps may be arbitrarily changed as long as no contradiction occurs. In this variation, the first control is constituted of Steps S471 to S475 in Fig. 10, and the second control is constituted of Steps S476 to S477 in Fig. 10.
[0131] The unit control section 50 temporarily stops the backward rotation of the package 22, and then performs the first rotation control. The first rotation control is a control including allowing the package 22 to rotate backward. The unit control section 50 allows the package 22 to perform the backward rotation as the first rotation control (Step S471). The unit control section 50 allows the package 22 to rotate backward and tries to catch the upper yarn end with the first catching unit 30.
[0132] Steps S472 to S477 are the same as Steps S74 to S79 in Fig. 4, and descriptions thereof are omitted.
[0133] (14) Variation N
In this embodiment, the unit control section 50 allows the pipe part 32 to turn to the predetermined position (illustrated by the dash-dot line in Fig. 2), and then sends a signal to the first motor 21, so as to perform the second rotation control, in which the package 22 is allowed to rotate backward at the second speed higher than the first speed (Step S77, at time point t5). However, at time point t5, the unit control section 50 may continue the backward rotation of the package 22 maintaining the first speed.
[0134] 4. Other Embodiments
Although embodiments of the present invention are described above, the present invention is not limited to the embodiments described above, but can be variously modified within the scope of the invention without deviating from the spirit thereof. In particular, the plurality of embodiments and variations described in this specification can be arbitrarily combined as necessary.

INDUSTRIAL APPLICABILITY
[0135] The yarn winding apparatus of the present disclosure can be applied to an automatic winder, an air spinning machine, or an open-end spinning machine, in which a plurality of yarn winding apparatuses are arranged and used. In addition, the yarn winding apparatus of the present disclosure can be widely applied to textile machinery for manufacturing fibers.
, Claims:We claim:

1. A yarn winding apparatus (10) comprising:
a yarn feeding unit (15) configured to feed yarn (14);
a winding unit (17) configured to wind the yarn (14) fed from the yarn feeding unit (15) so as to form a package (22);
a yarn splicing device (38) configured to splice yarn (14) on a side of the package (22) and yarn (14) on a side of the yarn feeding unit (15);
a first catching unit (30) configured to catch a yarn end on the side of the package (22) so as to guide the yarn (14) to the yarn splicing device (38);
a second catching unit (34) configured to catch a yarn end on the side of the yarn feeding unit (15) so as to guide the yarn (14) to the yarn splicing device (38);
a detection unit (40, 43) configured to detect the yarn (14) caught by the first catching unit (30); and
a control section (50), wherein
the control section (50) performs a first control and a second control,
in the first control, a first rotation control is performed which includes rotating the package (22) in an unwinding direction of the yarn (14), and in this state the first catching unit (30) is allowed to catch the yarn (14), and then if the yarn (14) is detected by the detection unit (40, 43), a second rotation control is performed in which the package (22) is further rotated in the unwinding direction of the yarn (14), and
in the second control, if the yarn (14) is not detected by the detection unit (40, 43) after the first control, first abnormality is informed.

2. The yarn winding apparatus (10) as claimed in claim 1, wherein
the control section (50) further performs a catching control, in which the package (22) is rotated at a first speed in the unwinding direction of the yarn (14), and in this state, the first catching unit (30) is allowed to catch the yarn (14), and the detection unit (40, 43) is allowed to detect the yarn (14), and
the first control is a control that is performed if the yarn (14) is not detected as a result of the catching control, and rotation speed of the package (22) in the second rotation control is a second speed higher than the first speed.

3. The yarn winding apparatus (10) as claimed in claim 2, wherein if the yarn (14) is detected as a result of the catching control, the control section (50) allows the package (22) to rotate at the first speed in the unwinding direction of the yarn (14).

4. The yarn winding apparatus (10) as claimed in claim 2 or 3, wherein the second speed is a speed four times or more and nine times or less the first speed.

5. The yarn winding apparatus (10) as claimed in one of claims 2 to 4, wherein the control section (50) changes the second speed on the basis of diameter of the package (22).

6. The yarn winding apparatus (10) as claimed in one of claims 2 to 5, wherein the control section (50) performs the first rotation control for allowing the package (22) to rotate at a third speed higher than the first speed in a winding direction of the yarn (14), and then for allowing the package (22) to rotate at the first speed in the unwinding direction of the yarn (14).

7. The yarn winding apparatus (10) as claimed in one of claims 1 to 6, wherein the control section (50) performs the first rotation control for allowing the package (22) to perform alternating rotation motion in which forward rotation in the winding direction of the yarn (14) and backward rotation in the unwinding direction are alternately performed.

8. The yarn winding apparatus (10) as claimed in one of claims 1 to 7, wherein the control section (50) allows the first catching unit (30) to separate from the package (22) before performing the second rotation control.
9. The yarn winding apparatus (10) as claimed in one of claims 1 to 8, wherein
the detection unit (40, 43) includes
a first detection unit (43) configured to detect the yarn (14) inside the first catching unit (30), and
a second detection unit (40) configured to detect the yarn (14) in a yarn travel path for the yarn (14) between the yarn feeding unit (15) and the winding unit (17), and
the control section (50) allows the first detection unit (43) to detect the yarn (14) in the first control, and allows the second detection unit (40) to detect the yarn (14) in the second control.

10. The yarn winding apparatus (10) as claimed in one of claims 1 to 9, wherein the control section (50) informs second abnormality if the yarn (14) is not detected by the detection unit (40, 43) in the first control.