YARN WINDING DEVICE

Abstract

 An automatic winder (yarn winding- device) includes a yarn storage device (19), a yarn joining device (14), an upper yarn pull-out section (18), and a control section. The yarn storage device (19) winds and temporarily stores a yarn (20) when a storage roller (61) is rotated. When guiding the yarn (20) from the yarn storage device (19) to the yarn joining device (14), the control section calculates an instructed number of reverse rotations, which is the number of times to rotate the storage roller (61) in a direction opposite to a direction of winding, and controls the storage roller (61) such that the number of reverse rotations of the storage roller (61) becomes the instructed number of reverse rotations.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0001] The present invention relates to a yarn winding device including a yarn storage device and a yarn joining device. Specifically, the present invention relates to a control carried out when pulling out a yarn from the yarn storage device during a yarn joining operation.

2. Description of the Related Art

[0002] Conventionally, there is known a yarn winding device adapted to wind a yarn from a yarn storage device to form a package while temporarily storing the yarn unwound from a yarn supplying bobbin on the yarn storage device. When the yarn winding device unwinds all the yarn of the yarn supplying bobbin, a new yarn supplying bobbin is supplied. The yarn winding device carries out winding of the new yarn supplying bobbin after the yarn joining device carries out a yarn joining operation of the yarn from the new yarn supplying bobbin and the yarn from the yarn storage device. JP 2010-47407 A and WO 2011/040545 A1 disclose this type of yarn winding device.

[0003] The yarn from the yarn supplying bobbin and the yarn from the yarn storage device are guided to the yarn joining device to carry out the yarn joining operation by the yarn joining device. Specifically, such yarns are caught with a pipe-shaped yarn guiding member that can generate a suction flow. The yarn guiding member guides the yarn to the yarn joining device by swinging while catching the yarn. Alternatively, the yarn guiding member guides the yarn to the yarn joining device by blowing the caught yarn.

[0004] JP 2010-47407 A discloses a yarn winding device adapted to store the yarn when a storage arm interiorly provided with a yarn passage rotates about a yarn pool section. The yarn winding device includes a clearer adapted to detect a yarn defect and a length thereof. When the yarn defect is detected, the yarn winding device estimates the length of the yarn defect based on a pulse signal transmitted from a driving section of the yarn storage device. Thus, the length of the yarn defect can be accurately estimated. Furthermore, WO 2011/040545 A1 discloses a yarn winding device adapted to store the yarn on an outer peripheral surface of the storage roller by rotating the storage roller.

[0005] In order to pull out the yarn from the yarn storage device and guide the yarn to the yarn joining device, the storage arm, the storage roller, and the like of the yarn storage device need to be rotated in a direction opposite to a direction of winding. However, JP 2010-47407 A and WO 2011/040545 A1 do not describe the details on the number of reverse rotations of the storage arm and the storage roller when carrying out the yarn joining operation. For example, when instructing a reverse rotation time in order to reversely rotate the storage arm or the storage roller, a length of the yarn to be pulled out varies according to the reverse rotation speed and the time until the reverse rotation speed is reached. Thus, it is necessary to instruct the reverse rotation time with margin so that the yarn of required length is surely pulled out. In this case, the yarn to be discarded becomes long and the time required for the yarn joining operation becomes long.

[0006] Furthermore, in the yarn winding device adapted to suck and catch the yarn on the surface of the storage roller as described in WO 2011/040545 A1, the surface of the storage roller is sucked for a long time when the catching of the yarn fails. As a result, the yarns wound around the storage roller may get entangled.

BRIEF SUMMARY OF THE INVENTION

[0007] The present invention has been made in view of the above circumstances, and a main object thereof is to provide a yarn winding device that can pull out a yarn from a yarn storage device by an appropriate amount when pulling out the yarn from the yarn storage device to guide the yarn to a yarn joining device.

[0008] The problems to be solved in the present invention are as described above, and the means for solving such problems and the effects thereof will be described below.

[0009] According to an aspect of the present invention, a yarn winding device having the following configuration is provided. More specifically, the yarn winding device includes a yarn supplying section, a yarn storage device, a package forming section, a yarn joining device, a storage yarn pull-out section, and a control section. The yarn supplying section is adapted to supply a yarn. The yarn storage device is adapted to wind the yarn from the yarn supplying section and temporarily store the yarn when a storage winding section is rotated. The package forming section is adapted to pull out the yarn from the yarn storage device and wind the yarn around a winding bobbin to form a package. The yarn joining device is adapted to join a disconnected yarn from the yarn supplying section and the yarn from the yarn storage device when the yarn is disconnected between the yarn supplying section and the yarn storage device. The storage yarn pull-out section is adapted to pull out the yarn from the yarn storage device from the yarn storage device and guide the yarn to the yarn joining device. The control section is adapted to carry out a reverse rotation control of rotating the storage winding section in a direction opposite to a direction of winding when guiding the yarn from the yarn storage device to the yarn joining device. The control section carries out a reverse rotation control of controlling the storage winding section such that a number of reverse rotations of the storage winding section becomes an instructed number of reverse rotations, which is the number of times to rotate the storage winding section in a direction opposite to the direction of winding.

[0010] Thus, when pulling out the yarn from the yarn storage device, the number of times to reversely rotate the storage winding section is instructed to accurately control a length of the yarn pulled out from the yarn storage device. Therefore, a length of the yarn to be discarded can be suppressed, and the time required for the yarn joining operation can be reduced.

[0011] In the above-described yarn winding device, the control section calculates the instructed number of reverse rotations, which is the number of times to rotate the storage winding section in a direction opposite to the direction of winding in the reverse rotation control, and the instructed number of reverse rotations is preferably calculated based on a length of a yarn stored when the storage winding section makes one rotation and a distance of a yarn path from the yarn storage device to the yarn joining device.

[0012] Thus, by taking into consideration the length of the yarn stored (unwound) when the storage winding section makes one rotation, the number of reverse rotations required for the yarn end to be caught by the storage yarn pull-out section from the start of reverse rotation can be estimated. Furthermore, by taking into consideration the distance of the yarn path from the yarn storage device to the yarn joining device, the number of reverse rotations required for guiding the pulled out yarn to the yarn joining device can be estimated.

[0013] In the above-described yarn winding device, the following configuration is preferably adopted. More specifically, the storage winding section is a storage roller adapted to wind the yarn around an outer peripheral surface and store the yarn. The length of the yarn stored when the storage winding section makes one rotation is calculated based on a radius or a diameter of the storage roller.

[0014] Thus, the storage amount (unwound amount) per one rotation of the storage roller can be calculated by simply carrying out a simple computation from the radius or the diameter. Conventionally, the winding amount per one rotation of the package is estimated, but since the diameter of the package becomes larger with increase in the winding amount of the yarn, a sensor for detecting the package diameter and the like is required in order to calculate the winding amount per one rotation. In this regard, since the storage roller has a constant diameter, the length of the yarn wound per one rotation can be easily and accurately calculated as opposed to the package.

[0015] In the above-described yarn winding device, the following configuration is preferably adopted. More specifically, in the yarn winding device, the storage yarn pull-out section includes a storage yarn catching section adapted to suck the yarn pulled out from the yarn storage device and catch the yarn at upstream of the yarn joining device. The instructed number of reverse rotations is further determined based on a distance of a yarn path from the yarn joining device to the storage yarn catching section.

[0016] Thus, the number of reverse rotations required for guiding the pulled out yarn to the yarn joining device can be more accurately estimated.

[0017] In the above-described yarn winding device, the following configuration is preferably adopted. More specifically, the yarn winding device includes a yarn defect detection device and a cutting section. The yarn defect detection device is adapted to detect a defect of the yarn wound by the yarn storage device. The cutting section is adapted to cut the yarn at upstream of the defect of the yarn when the defect of the yarn is detected by the yarn defect detection device. The instructed number of rotations is further determined based on a length of the yarn defect detected by the yarn defect detection device.

[0018] Thus, the number of reverse rotations required for guiding the pulled out yarn to the yarn joining device can be more accurately estimated while removing all the detected yarn defects. Furthermore, not only when the yarn supplying bobbin is supplied, but the yarn can be pulled out by the required sufficient length even when the yarn defect is detected.

[0019] In the above-described yarn winding device, the following configuration is preferably adopted. More specifically, the yarn winding device includes a yarn detecting section adapted to detect presence of the yarn at a predetermined area of the yarn path. The control section carries out the reverse rotation control again when the yarn is not detected by the yarn detecting section after the termination of the reverse rotation control.

[0020] Thus, the failure of the pull-out of the yarn can be detected, so that the pull-out of the yarn can be automatically carried out again without calling an operator. Furthermore, the length of the yarn to be pulled out can be accurately controlled in the present invention, and hence the failure of the pull-out of the yarn can be more accurately detected.

[0021] In the above-described yarn winding device, the yarn defect detection device preferably functions as a yarn detecting section.

[0022] Thus, the number of components in the yarn winding device can be reduced, and the manufacturing cost of the yarn winding device can be reduced.

[0023] In the above-described yarn winding device, the following configuration is preferably adopted. More specifically, the storage yarn pull-out section sucks the yarn from the yarn storage device, passes the yarn through a suction passage formed inside the storage yarn pull-out section, and pulls out the yarn. A pull-out yarn detecting section adapted to detect the presence of the yarn is arranged on the suction passage. The control section starts counting of the number of reverse rotations of the storage yarn pull-out section at a timing at which the yarn is detected by the pull-out yarn detecting section.

[0024] Thus, the pull-out of the yarn can be immediately detected, whereby the amount of yarn to be pulled out can be further suppressed as compared to the case where the storage yarn pull-out section is rotated once in the reverse direction to pull out the yarn. Furthermore, since the pull-out of the yarn can be rapidly detected, the mistakes in pulling out the yarn can be reliably detected at an early stage.

[0025] In the above-described yarn winding device, an input section to which the instructed number of reverse rotations or a value used to calculate the instructed number of reverse rotations are input is preferably arranged.

[0026] Thus, it is possible to easily deal with change in the type of yarn, change in the position of the yarn storage device, the yarn joining device, and the like, or change in the shape of the yarn storage device. The yarn supplying section is preferably a yarn supplying bobbin supporting section adapted to support the yarn supplying bobbin for supplying the yarn.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 

FIG. 1 is a schematic side view of a winding unit arranged in an automatic winder according to one embodiment of the present invention;

FIG. 2 is a schematic side view of a winding unit immediately after a yarn blown by an upper yarn pull-out section is caught by an upper yarn catching section;

FIG. 3 is a schematic side view of a winding unit illustrating a state in which a lower yarn and an upper yarn are guided to a yarn joining device;

FIG. 4 is an explanatory view illustrating a length required for guiding the yarn pulled out from the yarn storage device to the yarn joining device;

FIG. 5 is an explanatory view illustrating a length required for removing all yarn defects in the yarn by carrying out a yarn joining operation;

FIG. 6 is a flowchart illustrating a process of calculating an instructed number of reverse rotations; and

FIG. 7 is a schematic enlarged side view of a winding unit arranged in an automatic winder according to an alternative embodiment.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0028] Embodiments of the present invention will be hereinafter described. First, an outline of an automatic winder (yarn winding device) will be described with reference to FIG. 1. The automatic winder has a configuration in which a plurality of winding units 2 are arranged in a row. The automatic winder includes a machine management device (not illustrated) adapted to intensively manage the winding units 2, and a blower box (not illustrated) including a compressed air source and a negative pressure source.

[0029] As illustrated in FIG. 1, the winding unit 2 mainly includes a control section 50, a yarn supplying bobbin supporting section (yarn supplying section) 7, and a winding section (package forming section) 8. The winding unit 2 unwinds a yarn (spun yarn) 20 of a yarn supplying bobbin 21 supported by the yarn supplying bobbin supporting section 7, and winds the yarn into a package 30. In the following description, an upstream side and a downstream side when seen in a travelling direction of the yarn are simply referred to as "upstream" and "downstream".

[0030] The control section 50 is configured by hardware such as CPU, ROM, RAM (not illustrated), and software such as a control program stored in the ROM. Each section of the winding unit 2 is controlled by a cooperative operation of the hardware and the software. The control section 50 of each winding unit 2 can communicate with the above-described machine management device. Thus, the operations of the plurality of winding units 2 arranged in the automatic winder can be intensively managed in the machine management device.

[0031] The automatic winder includes an input section 51 adapted to input winding conditions and the like of the control section 50. The input section 51 may be provided for each winding unit 2, or may be arranged in the machine management device.

[0032] The yarn supplying bobbin supporting section 7 holds the yarn supplying bobbin 21 in a substantially upright state. The yarn supplying bobbin supporting section 7 can discharge the empty yarn supplying bobbin 21. A magazine type bobbin supplying device 26 is arranged on the front side of the winding unit 2. The bobbin supplying device 26 includes a rotary magazine can 27. The magazine can 27 can hold a plurality of spare yarn supplying bobbins 21. The bobbin supplying device 26 intermittently rotatably drives the magazine can 27 to supply a new yarn supplying bobbin 21 to the yarn supplying bobbin supporting section 7.

[0033] The winding section 8 includes a cradle 23 to which a winding bobbin 22 can be set, and a traverse drum 24 adapted to traverse the yarn 20 and drive the winding bobbin 22.

[0034] The traverse drum 24 is arranged facing the winding bobbin 22. When the traverse drum 24 is rotatably driven by a motor (not illustrated), the winding bobbin 22 and the package 30 rotate accompanying the rotation of the traverse drum 24. Thus, the yarn 20 stored in the yarn storage device 19, to be described later, can be wound into a package 30.

[0035] A traverse groove (not illustrated) is formed on the outer peripheral surface of the traverse drum 24, and the yarn 20 can be traversed at a predetermined width by the traverse groove. According to the above configuration, the package 30 of a predetermined shape can be formed by winding the yarn 20 around the winding bobbin 22 while traversing the yarn 20.

[0036] The winding unit 2 includes an unwinding assisting device 10, a lower yarn blow-up section 11, a gate type tensor 12, an upper yarn catching section (storage yarn catching section) 13, a yarn joining device 14, a yarn trap 15, a cutter (cutting section) 16, a yarn monitoring device (yarn defect detection device) 17, an upper yarn pull-out section (storage yarn pull-out section) 18, and a yarn storage device 19 in this order from the yarn supplying bobbin supporting section 7 towards the winding section 8 on a yarn travelling path between the yarn supplying bobbin supporting section 7 and the winding section 8.

[0037] The unwinding assisting device 10 brings a movable member 10a into contact with a balloon formed at the upper part of the yarn supplying bobbin 21 when the yarn 20 unwound from the yarn supplying bobbin 21 is swung. The size of the balloon thus can be appropriately controlled, and the unwinding of the yarn 20 is assisted.

[0038] The lower yarn blow-up section 11 is an air sucker device arranged between the yarn supplying bobbin supporting section 7 and the yarn joining device 14, and feeds a lower yarn from the yarn supplying bobbin 21 towards the yarn joining device 14 during the yarn joining operation.

[0039] The gate type tensor 12 applies a predetermined tension on the travelling yarn 20. The gate type tensor 12 of the present embodiment is a gate type tensor in which movable comb teeth are arranged with respect to fixed comb teeth. The movable comb teeth are swung by a rotary solenoid such that the movable comb teeth are engaged with or released from the fixed comb teeth. A disc type tension applying device, for example, may be arranged in place of the tension applying device of the gate type tensor 12.

[0040] The upper yarn catching section 13 is arranged between the yarn joining device 14 and the yarn supplying bobbin supporting section 7. The upper yarn catching section 13 is connected to the negative pressure source (not illustrated), and can generate a suction airflow during the yarn joining operation. The processes carried out by each section of the winding unit 2 during the yarn joining operation will be described later.

[0041] The yarn trap 15 is arranged between the yarn joining device 14 and the yarn storage device 19. A distal end of the yarn trap 15 is formed as a tubular member, and is provided proximate to the travelling path of the yarn 20. The yarn trap 15 is connected to the negative pressure source (not illustrated), and generates the suction airflow at the distal end to suck and remove contaminants such as fluffs attached to the travelling yarn 20.

[0042] The yarn monitoring device 17 is configured to detect the yarn defect such as slub by monitoring a thickness of the yarn 20 with an optical or capacitance sensor. When the yarn defect is detected, the yarn monitoring device 17 outputs to the control section 50 a disconnected signal instructing cutting and removal of the yarn defect. Since the yarn defect sometimes has a length of a certain extent, specifically, the disconnected signal is output to the control section 50 at timing at which the yarn defect is no longer detected. A cutter 16 adapted to immediately cut the yarn 20 according to the disconnected signal input through the control section 50 is arranged in proximity to the yarn monitoring device 17. The yarn monitoring device 17 outputs the length of the detected yarn defect to the control section 50.

[0043] The yarn joining device 14 joins the lower yarn from the yarn supplying bobbin 21 and an upper yarn from the yarn storage device 19 in the disconnected state when the yarn defect is detected by the yarn monitoring device 17 and the yarn 20 is cut by the cutter 16, when the yarn 20 unwound from the yarn supplying bobbin 21 breaks, when replacing the yarn supplying bobbin 21, and the like. The yarn joining device 14 may be a type that uses fluid such as compressed air or a mechanical-type.

[0044] The upper yarn pull-out section 18 is an air sucker device arranged immediately upstream of the yarn storage device 19, and is adapted to feed the upper yarn from the yarn storage device 19 towards a yarn guiding pipe 36 by the compressed air.

[0045] The yarn storage device 19 temporarily stores the yarn 20 unwound from the yarn supplying bobbin 21. As illustrated in FIG. 1, the yarn storage device 19 mainly includes a storage roller (storage winding section) 61, a storage roller drive motor 62, and an annular member 63.

[0046] The storage roller 61 is formed as a substantially cylindrical member, and pulls out the yarn 20 from the yarn supplying bobbin 21 by rotating about a center axis line, and winds and stores the yarn 20 around the outer peripheral surface thereof. The storage roller drive motor 62 is a motor capable of controlling a rotation amount of a stepping motor, a servo motor, or the like. The storage roller drive motor 62 rotatably drives the storage roller 61 about the center axis line. The operation of the storage roller drive motor 62 is controlled by the control section 50. In the following description, rotating the storage roller 61 in the direction opposite to the direction of winding the yarn 20 from the yarn supplying bobbin 21 may be referred to as "reversely rotate" and the like.

[0047] The winding unit 2 stores a constant amount of yarn 20 in the yarn storage device 19, and thus the yarn 20 stored in the yarn storage device 19 can be wound even when the unwinding of the yarn 20 from the yarn supplying bobbin 21 is interrupted for some reason (e.g., when the yarn joining operation is carried out). Thus, the winding of the yarn 20 to the package 30 can be continued even when the unwinding of the yarn 20 is interrupted.

[0048] The annular member 63 is arranged in proximity to the end on the downstream of the storage roller 61. The yarn 20 stored in the yarn storage device 19 is passed between the annular member 63 and the surface of the storage roller 61 and pulled out towards the downstream. According to such a configuration, an appropriate tension can be applied to the yarn 20 unwound from the storage roller 61, so that the unwinding of the yarn 20 can be stabilized.

[0049] When the yarn joining operation is carried out, the control section 50 first blows up the yarn 20 from the yarn supplying bobbin 21 upward by the lower yarn blow-up section 11. The blown-up yarn 20 is sucked and caught by the yarn trap 15 (see FIG. 2). Thus, the yarn 20 from the yarn supplying bobbin 21 can be guided to the yarn joining device 14.

[0050] The yarn end formed by the yarn breakage, the yarn cutting, or the like is wound by the storage roller 61. Thus, the control section 50 reversely rotates the storage roller 61 for a predetermined number of times while generating the suction flow in the upper yarn pull-out section 18. Thus, the yarn end of the yarn 20 located at the surface of the storage roller 61 is sucked and caught by the upper yarn pull-out section 18. The process of calculating how much the storage roller 61 is reversely rotated will be described later.

[0051] The upper yarn pull-out section 18 blows the sucked and caught yarn 20 towards the yarn guiding pipe 36. The yarn 20 is fed along the yarn guiding pipe 36, and sucked and caught by the upper yarn catching section 13 (see FIG. 2). The yarn guiding pipe 36 is provided with a slit (not illustrated) along a longitudinal direction, and the yarn 20 can be taken out from the slit by continuing the sucking of the yarn 20 by the upper yarn catching section 13. Thus, the yarn 20 from the yarn storage device 19 can be guided to the yarn joining device 14 (see FIG. 3). In this case, the yarn 20 is also guided to a detection region of the yarn monitoring device 17, and thus success or failure of the pull-out of the yarn 20 can be determined based on the detection result of the yarn monitoring device 17.

[0052] The control section 50 activates the yarn joining device 14 with the yarn from the yarn supplying bobbin 21 and the yarn from the yarn storage device 19 guided to the yarn joining device 14 to join the yarns 20. After the yarn joining operation is completed, the control section 50 resumes the winding of the yarn 20 to the yarn storage device 19 by rotating the yarn storage device 19 in the direction of winding.

[0053] Even when the yarn 20 is in the disconnected state between the yarn supplying bobbin 21 and the yarn storage device 19 as described above, the winding of the yarn 20 into the package 30 in the winding section 8 can be continued without being interrupted. In other words, in the automatic winder of the present embodiment, the yarn storage device 19 is interposed between the yarn supplying bobbin supporting section 7 and the winding section 8, and a constant amount of yarn 20 is stored on the yarn storage device 19. The winding section 8 is configured to wind the yarn 20 stored on the yarn storage device 19. Therefore, even when the supply of the yarn 20 from the yarn supplying bobbin 21 is interrupted for some reason (e.g., when the yarn joining operation is carried out), the winding of the yarn 20 into the package 30 can be continued.

[0054] Thus, the winding operation in the winding section 8 is not interrupted by the yarn joining operation, so that the package 30 can be stably produced at high speed. Since the yarn storage device 19 is arranged between the yarn supplying bobbin 21 and the winding section 8, the winding in the winding section 8 can be carried out without being affected by variation of tension at the time of unwinding the yarn 20 from the yarn supplying bobbin 21.

[0055] Next, a description will be made on the process of determining the number of times to reversely rotate the storage roller 61 during the yarn joining operation with reference to FIGS. 4 to 6.

[0056] In the present embodiment, when reversely rotating the storage roller 61, the number of times to reversely rotate the storage roller 61 is instructed rather than the time during which the storage roller 61 is reversely rotated. Hereinafter, the instructed number of times to reversely rotate may be referred to as the instructed number of reverse rotations. The "instructed number of reverse rotations" in the present specification is not limited to an integer, and includes a value between the integers (e.g., 1.5 rotations or the like). Furthermore, the "instructed number of reverse rotations" merely needs to substantially instruct the number of times to reversely rotate the storage roller 61, and for example, includes a case of instructing an angle (720 degrees or the like) to reversely rotate.

[0057] In the present embodiment, the instructed number of reverse rotations is calculated based on a "length L1 required for pulling out the yarn 20", a "length L2 required for guiding the yarn 20 from the yarn storage device 19 to the yarn joining device 14", a "length L3 required for sucking the yarn 20 with the upper yarn catching section 13", and a "length L4 for removing all yarn defects contained in the yarn 20".

[0058] First, a description will be made on the "length L1 required for pulling out the yarn 20 (hereinafter referred to as length L1)" with reference to FIG. 4. As described above, when carrying out the yarn joining operation, the yarn end of the yarn 20 is wound around the storage roller 61, and this yarn end needs to be caught to pull out the yarn 20. At this time, the control section 50 cannot specify at which position of the storage roller 61 the yarn end of the yarn 20 exists.

[0059] When the storage roller 61 makes one rotation, regardless of where the yarn end is located on the storage roller 61, the yarn end reliably passes in front of a suction port of the upper yarn pull-out section 18. Thus, a length (hereinafter referred to as outer peripheral length) of one round of the outer peripheral surface of the storage roller 61 is calculated as the length L1. The outer peripheral length of the storage roller 61 can be expressed as "length of the yarn 20 wound or unwound by rotating the storage roller 61 once".

[0060] The length L1 can be calculated from a radius (radius r of FIG. 4) or a diameter of the storage roller 61. The radius or the diameter of the storage roller 61 may be stored in the control section 50 (or machine control device, similarly hereinafter) in advance at the time of product shipment. The outer peripheral length (i.e., length L1) of the storage roller 61 may be stored in the control section 50 in advance. Furthermore, when the radius and the like of the storage roller 61 are not stored in advance or when the storage roller 61 is replaced, the radius and the like input by the operator using the input section 51 can be stored in the control section 50.

[0061] Next, a description will be made on the "length L2 required for guiding the yarn 20 from the yarn storage device 19 to the yarn joining device 14 (hereinafter referred to as length L2)" with reference to FIG. 4. FIG. 4 illustrates a state where the yarn 20 is guided to the yarn joining device 14. As illustrated in FIG. 4, at least the yarn 20 having a length from the yarn storage device 19 to the yarn joining device 14 is required in order to guide the yarn 20 to the yarn joining device 14.

[0062] As illustrated in FIG. 4, in the layout of the present embodiment, the length L2 is calculated by adding a length L21 of the yarn path from the yarn storage device 19 to the yarn monitoring device 17, and a length L22 of the yarn path from the yarn monitoring device 17 to the yarn joining device 14. A starting point of the length L21 is preferably an area, where the yarn 20 is pulled out, in the yarn storage device 19 (upstream end of the storage roller 61 in the present embodiment). A terminating point of the length L22 is preferably a position where the yarn 20 to be joined in the yarn joining device 14 is cut.

[0063] Depending on the layout of the yarn winding device, the yarn 20 may not pass the yarn monitoring device 17 or the yarn 20 may pass other devices. In this case as well, the length L2 can be calculated by obtaining the "length of the yarn path from the yarn storage device to the yarn joining device in the yarn path when the yarn is guided to the yarn joining device".

[0064] Next, a description will be made on the "length L3 required for sucking the yarn 20 with the upper yarn catching section 13 (hereinafter referred to as length L3)" with reference to FIG. 4. In order to guide the yarn 20 to the yarn joining device 14, the yarn 20 needs to be sucked by the upper yarn catching section 13.

[0065] As illustrated in FIG. 4, in the layout of the present embodiment, the length L3 is calculated by adding a length L31 from the position where the yarn 20 is cut in the yarn joining device 14 to the upstream guide of the yarn joining device 14, a length L32 from the guide to the upper yarn catching section 13, and a length L33 for causing the suction force to act on the yarn 20 caught by the upper yarn catching section 13. Furthermore, a starting point of the length L31 is preferably a position where the yarn 20 to be joined in the yarn joining device 14 is cut.

[0066] In the present embodiment, the yarn 20 is guided to make a slight detour using the yarn guiding pipe 36, and thus a correction value that takes into consideration such an amount can be further added to obtain the length L3.

[0067] Depending on the layout of the yarn winding device, the yarn may pass other devices. In this case as well, the length L3 can be calculated by obtaining the "length of the yarn path from the yarn joining device to the upper yarn catching section (portion of catching the upper yarn on the upstream side of the yarn joining device) in the yarn path when the yarn is guided to the yarn joining device".

[0068] The length L2 and the length L3 can be calculated based on the layout of each device and the yarn path. The layout of each device and the yarn path, or the calculated lengths L2 and L3 may be stored in the control section 50 in advance at the time of product shipment, similarly to the length L1. When the layout or the component is replaced, the value input by the operator using the input section 51 can be stored in the control section 50.

[0069] Next, a description will be made on the "length L4 for removing all yarn defects contained in the yarn 20 (hereinafter referred to as length L4) ". As illustrated in FIG. 5, the yarn defect may have a length of a certain extent. In this case, after the yarn joining operation, to remove all the portions including the yarn defect, the portion including the yarn defect needs to be prevented from remaining on the yarn storage device 19 side of the yarn joining device 14. Therefore, in addition to the length L1 and the length L2, an amount corresponding to the length of the yarn defect needs to be further pulled out from the storage roller 61.

[0070] The yarn monitoring device 17 monitors the yarn defect during the winding, and cuts the yarn 20 by the cutter 16 after detecting that all the yarn defects have passed and a normal yarn is obtained. Thus, a slight displacement may occur between the upstream end of the yarn defect and the yarn cutting position (i.e., position of yarn end). In view of the above, the length L4 is calculated by adding a length L41 of the yarn 20 of the portion including the yarn defect and a length L42 of the normal yarn from the position where the yarn defect is not detected to the yarn end.

[0071] Next, a description will be made on a process in which the control section calculates the instructed number of reverse rotations when carrying out the yarn joining operation based on the lengths L1 to L4 described above, with reference to FIG. 6. First, the control section 50 calculates the lengths L1, L2, and L3 described above (S101, S102, S103). When the lengths L1, L2, and L3 are stored, the lengths may be read out.

[0072] The control section 50 carries out a determination on whether or not the cause of the yarn joining operation is the detection of the yarn defect (S104). When the cause of the yarn joining operation is other than the yarn defect (e.g., replacement of yarn supplying bobbin 21), the yarn 20 merely needs to be guided to the yarn joining device 14 (portion to be removed such as a yarn defect is not present). Therefore, the length L to be reversely rotated (hereinafter referred to as length L) is calculated by adding the length L1, the length L2, and the length L3 (S105).

[0073] The control section 50 acquires the length L4 from the yarn monitoring device 17 when the cause of the yarn joining operation is the detection of the yarn defect (S106). The control section 50 carries out the determination on whether or not the acquired length L4 is longer than the length L3 (S107).

[0074] When the length L4 is longer than the length L3, the yarn 20 can be passed from the yarn joining device 14 to the upper yarn catching section 13 using the yarn 20 of the portion corresponding to the length L4. In other words, the yarn 20 of the portion to be removed serves as the length L3.

[0075] Furthermore, the yarn 20 can be passed from the yarn storage device 19 to the yarn joining device 14 by pulling out the yarn 20 by an amount corresponding to the length L1 and the length L2. Furthermore, the portion including the yarn defect is not supplied to the yarn joining device 14 by adding the length L4. Therefore, the yarn defect can be removed from the yarn 20. Accordingly, when the length L4 is longer than the length L3, the length L to be reversely rotated is calculated by adding the length L1, the length L2, and the length L4 (S108).

[0076] When the length L4 is shorter than the length L3, the yarn 20 cannot be passed to the upper yarn catching section 13 even when the length L4 is added to the length L1 and the length L2. Therefore, when the length L4 is shorter than the length L3, the length L to be reversely rotated is calculated by adding the length L1, the length L2, and the length L3 (S105).

[0077] The control section 50 determines the length L in the above manner, and divides the length L by the outer peripheral length of the storage roller 61 to calculate the instructed number of reverse rotations corresponding to the length L (S109). The control section 50 controls the storage roller drive motor 62 such that the storage roller 61 is reversely rotated by an amount corresponding to the reverse rotation instructed length calculated in the above manner. An instructing mode of the instructed number of reverse rotations includes, for example, a mode of instructing with the number of pulses, the width of the pulse, and the like.

[0078] Thereafter, the control section 50 determines whether or not the yarn monitoring device 17 has detected the presence of the yarn 20. When the yarn monitoring device 17 has not detected the presence of the yarn 20, the pull-out of the yarn 20 is assumed to have failed as described above. Thus, for example, the pull-out of the yarn 20 is carried out again after the yarn end is made easy to catch by rotating the storage roller 61 once in the winding direction, and the like. When the pull-out of the yarn 20 has failed continuously for a predetermined number of times, the control section 50 sets out an alarm to notify the operator.

[0079] As described above, the automatic winder includes the yarn supplying bobbin supporting section 7, the yarn storage device 19, the winding section 8, the yarn joining device 14, the upper yarn pull-out section 18, and the control section 50. The yarn supplying bobbin supporting section 7 supplies the yarn 20. The yarn storage device 19 winds and temporarily stores the yarn 20 supplied by the yarn supplying bobbin supporting section 7 when the storage roller 61 is rotated. The winding section 8 pulls out the yarn 20 from the yarn storage device 19 and winds the yarn 20 around the winding bobbin 22 to form the package 30. When the yarn 20 is disconnected between the yarn supplying bobbin supporting section 7 and the yarn storage device 19, the yarn joining device 14 joins the yarn 20 from the yarn supplying bobbin supporting section 7 and the yarn 20 from the yarn storage device 19. The upper yarn pull-out section 18 pulls out the yarn 20 from the yarn storage device 19 from the yarn storage device 19 and guides the yarn 20 to the yarn joining device 14. When guiding the yarn 20 from the yarn storage device 19 to the yarn joining device 14, the control section 50 calculates the instructed number of reverse rotations, which is the number of times to rotate the storage roller 61 in a direction opposite to the direction of winding, and carries out a reverse rotation control of controlling the storage roller 61 such that the number of reverse rotations of the storage roller 61 become the instructed number of reverse rotations.

[0080] Thus, when pulling out the yarn 20 from the yarn storage device 19, the number of times to reversely rotate the storage roller 61 is instructed so that the length of the yarn 20 to be pulled out from the yarn storage device 19 can be reliably controlled. Therefore, the length of the yarn 20 to be discarded can be suppressed, and the time required for the yarn joining operation can be reduced.

[0081] In the automatic winder of the present embodiment, the instructed number of reverse rotations is calculated based on the length (length L1) of the yarn 20 stored or unwound when the storage roller 61 makes one rotation, and the distance (length L2) of the yarn path from the yarn storage device 19 to the yarn joining device 14.

[0082] The length of the yarn 20 stored (unwound) when the storage roller 61 makes one rotation is thus taken into consideration, so that the number of reverse rotations required for the yarn end to be caught by the upper yarn pull-out section 18 from the start of reverse rotation can be estimated. Furthermore, the distance of the yarn path from the yarn storage device 19 to the yarn joining device 14 is taken into consideration, so that the number of reverse rotations required for guiding the pulled out yarn 20 to the yarn joining device 14 can be estimated.

[0083] In the automatic winder of the present embodiment, the storage roller 61 winds the yarn 20 around the outer peripheral surface thereof to store the yarn 20. The length (length L1) of the yarn 20 stored or unwound when the storage roller 61 makes one rotation is calculated based on the radius or the diameter of the storage roller 61.

[0084] Thus, the storage amount (unwound amount) per one rotation of the storage roller can be calculated by carrying out a simple computation from the radius or the diameter.

[0085] Moreover, the automatic winder of the present embodiment includes the upper yarn catching section 13 adapted to suck the yarn 20 pulled out from the yarn storage device 19 by the upper yarn pull-out section 18 and catch the yarn 20 on the upstream of the yarn joining device 14. The instructed number of reverse rotations is further determined based on the distance (length L3) of the yarn path from the yarn joining device 14 to the upper yarn catching section 13.

[0086] Thus, the number of reverse rotations required for guiding the pulled out yarn 20 to the yarn joining device 14 can be more accurately estimated.

[0087] The automatic winder of the present embodiment further includes the yarn monitoring device 17 and the cutter 16. The yarn monitoring device 17 detects the defect of the yarn 20 from the upstream of the yarn storage device 19. The cutter 16 cuts the yarn 20 on the upstream of the yarn defect when the yarn defect is detected by the yarn monitoring device 17. The instructed number of reverse rotations is also determined based on the length of the yarn defect detected by the yarn monitoring device 17.

[0088] Thus, the number of reverse rotations required for guiding the pulled out yarn 20 to the yarn joining device 14 can be more accurately estimated while removing all the detected yarn defects. Furthermore, not only when the yarn supplying bobbin 21 is newly supplied, but the yarn 20 can also be pulled out by the required sufficient length even when the yarn defect is detected.

[0089] Next, a description will be made on an alternative embodiment of the above-described embodiment with reference to FIG. 7. In the description of the alternative embodiment, the same reference numerals are denoted in the figures for the members same as or similar to those of the above-described embodiment, and the description thereof may be omitted.

[0090] In the above-described embodiment, the storage roller 61 is reversely rotated by an amount corresponding to the instructed number of reverse rotations with respect to the storage roller 61 in a stationary state. In other words, the counting of the number of reverse rotations is started immediately after the storage roller 61 starts to rotate reversely. On the other hand, in this alternative embodiment, the counting of the number of reverse rotations is started from the timing at which the storage roller 61 starts to rotate reversely and the upper yarn pull-out section 18 catches the yarn 20. Thus, in this alternative embodiment, the length L1 in the above-described embodiment does not need to be taken into consideration, so that the instructed number of reverse rotations becomes "length L2 + length L3" or "length L2 + length L4".

[0091] The winding unit 2 of this alternative embodiment includes a pull-out yarn detecting section 18a, illustrated in FIG. 7, adapted to detect the catching of the yarn 20 by the upper yarn pull-out section 18. The pull-out yarn detecting section 18a is an optical sensor arranged in a suction passage 18b. The pull-out yarn detecting section 18a may be a reflective sensor adapted to detect a reflected light, in which the irradiated light is reflected by the yarn 20, or may be a transmissive sensor adapted to detect shielding of the irradiated light by the yarn 20. The pull-out yarn detecting section 18a is not limited to the optical sensor, and may be a capacitance sensor or a contact sensor. The pull-out yarn detecting section 18a outputs the detection result to the control section 50. The control section 50 starts the counting of the number of reverse rotations when determined that the yarn 20 is present from the detection result.

[0092] The preferred embodiments of the present invention have been described above, but the above-described configurations may be modified as below.

[0093] In the above-described embodiment, the yarn storage device 19 in which the yarn 20 is wound around the outer peripheral surface by rotating the storage roller 61 is used. Alternatively, a yarn storage device may be used in which the yarn is stored in the storage body by rotating, about the storage body, an arm-shaped winding member (storage winding section) interiorly provided with the yarn passage. In this case, L1 to L4 are calculated from the number of rotations of the arm-shaped winding member.

[0094] In the above-described embodiment, the success and failure of the pull-out of the yarn 20 is determined by detecting the presence of the yarn 20 by the yarn monitoring device 17, but the success and failure of the pull-out of the yarn 20 may be determined by the pull-out yarn detecting section 18a.

[0095] In the above-described embodiment, the storage roller drive motor 62 is controlled by the control section 50 adapted to carry out the control of each section of the winding unit 2, but the storage roller drive motor 62 may be controlled by a motor control section arranged separately from the control section 50. In the above-described embodiment, the reverse rotation control is carried out by the control section 50 arranged for each winding unit 2, but the process carried out in the reverse rotation control may be partially or entirely carried out in the machine control device. Only the detection of the state of the yarn 20 may be carried out in the yarn monitoring device 17, and the analysis may be carried out in the control section 50 or the machine control device.

[0096] In the above-described embodiment, an example of supplying the yarn supplying bobbin 21 by the magazine type bobbin supplying device 26 has been described, but a yarn winding device including the tray type bobbin supplying device may be adopted.

[0097] The configuration of the present invention is not limited to the automatic winder, and is also applicable to other types of yarn winding devices including the yarn storage device and the yarn joining device.

Claims

1. A yarn winding device comprising:

a yarn supplying section (7) adapted to supply a yarn;

a yarn storage device (19) adapted to wind the yarn from the yarn supplying section (7) and temporarily store the yarn when a storage winding section (61) is rotated;

a package forming section (8) adapted to pull out the yarn from the yarn storage device (19) and wind the yarn around a winding bobbin to form a package;

a yarn joining device (14) adapted to join a disconnected yarn from the yarn supplying section and a yarn from the yarn storage device (19) when the yarn is disconnected between the yarn supplying section (7) and the yarn storage device (19);

a storage yarn pull-out section (18) adapted to pull out the yarn from the yarn storage device (19) from the yarn storage device (19) and guide the yarn to the yarn joining device (14); characterized by:

a control section (50) adapted to carry out a reverse rotation control of rotating the storage winding section (61) in a direction opposite to a direction of winding when guiding the yarn from the yarn storage device (19) to the yarn joining device (14),

wherein the control section (50) controls the storage winding section (61) such that a number of reverse rotations of the storage winding section (61) becomes a determined instructed number of reverse rotations in the reverse rotation control.

2. The yarn winding device according to claim 1, characterized in that
the control section (50) calculates the instructed number of reverse rotations in the reverse rotation control, and
the instructed number of reverse rotations is calculated based on a length of a yarn stored when the storage winding section (61) makes one rotation and a distance of a yarn path from the yarn storage device (19) to the yarn joining device (14).

3. The yarn winding device according to claim 2, characterized in that
the storage winding section (61) is a storage roller (61) adapted to wind the yarn around an outer peripheral surface and store the yarn, and
the length of the yarn stored when the storage winding section (61) makes one rotation is calculated based on a radius or a diameter of the storage roller (61)

4. The yarn winding device according to claim 2 or 3, characterized in that
the storage yarn pull-out section (18) includes a storage yarn catching section (13) adapted to suck the yarn pulled out from the yarn storage device (19) and catch the yarn at upstream of the yarn joining device (14), and
the instructed number of reverse rotations is further determined based on a distance of a yarn path from the yarn joining device (14) to the storage yarn catching section (13).

5. The yarn winding device according to any one of claims 2 to 4, characterized by further comprising:

a yarn defect detection device (17) adapted to detect a defect of the yarn wound by the yarn storage device (19); and

a cutting section (16) adapted to cut the yarn at upstream of the defect of the yarn when the defect of the yarn is detected by the yarn defect detection device (17),

wherein the instructed number of rotations is further determined based on a length of the yarn defect detected by the yarn defect detection device (17).

6. The yarn winding device according to claim 5, characterized by further comprising:

a yarn detecting section (17, 18a) adapted to detect presence of the yarn at a predetermined area of the yarn path,

wherein the control section (50) carries out the reverse rotation control again when the yarn is not detected by the yarn detecting section (17, 18a) after termination of the reverse rotation control.

7. The yarn winding device according to claim 6, characterized in that
the yarn defect detection device (17) functions as the yarn detecting section.

8. The yarn winding device according to any one of claims 1 to 5, characterized in that
the storage yarn pull-out section (18) sucks the yarn from the yarn storage device (19), passes the yarn through a suction passage formed inside the storage yarn pull-out section (18), and pulls out the yarn,
a pull-out yarn detecting section (18a) adapted to detect the presence of the yarn is arranged on the suction passage, and
the control section (50) starts counting of the number of reverse rotations of the storage yarn pull-out section (18) at a timing at which the yarn is detected by the pull-out yarn detecting section (18a).

9. The yarn winding device according to claim 6, characterized in that
the storage yarn pull-out section (18) sucks the yarn from the yarn storage device (19), passes the yarn through a suction passage formed inside the storage yarn pull-out section (18), and pulls out the yarn,
a pull-out yarn detecting section (18a) adapted to detect the presence of the yarn is arranged on the suction passage,
the pull-out yarn detecting section (18a) functions as the yarn detecting section, and
the control section (50) starts counting of the number of reverse rotations of the storage yarn pull-out section (18) at a timing at which the yarn is detected by the pull-out yarn detecting section (18a).

10. The yarn winding device according to any one of claims 2 to 9, characterized by further comprising:

an input section (51) to which the instructed number of reverse rotations or a value used to calculate the instructed number of reverse rotations are input.

11. The yarn winding device according to any one of claims 1 to 10, characterized in that
the yarn supplying section (7) is a yarn supplying bobbin supporting section adapted to support the yarn supplying bobbin for supplying the yarn.

Drawing