EP2298971A1

EP2298971A1 - Spinning machine with yarn accumulating roller

Info

Publication number: EP2298971A1
Application number: EP10162086A
Authority: EP
Inventors: Masaki Oka; Hiroyuki Susami
Original assignee: Murata Machinery Ltd
Current assignee: Murata Machinery Ltd
Priority date: 2009-08-10
Filing date: 2010-05-06
Publication date: 2011-03-23
Anticipated expiration: 2030-05-06
Also published as: CN101994174A; JP2011037572A; EP2298971B1; CN101994174B

Abstract

A spinning frame includes a yarn accumulating roller (21), an electric motor (25), and a unit controller (60). The yarn accumulating roller (21) temporarily accumulates a spun yarn produced by a spinning device (9) by winding the spun yarn around an outer peripheral surface thereof and rotating. The electric motor (25) drives and rotates the yarn accumulating roller (21). The unit controller (60) carries out a first control to control the electric motor (25) to rotate the yarn accumulating roller backward when it is necessary to unwind the spun yarn wound around the yarn accumulating roller. Next, the unit controller (60) carries out a second control to control the electric motor (25) to rotate the yarn accumulating roller (21) backward at a speed which is higher than a rotational speed during the first control. Then, the unit controller (60) carries out a control to spin off a yarn entangled with a flyer (38) or the like by temporarily increasing a backward rotational speed of the yarn accumulating roller (21) during the second control.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a spinning machine including a yarn accumulating roller.

2. Description of the Related Art

Japanese Unexamined Patent Application Publication No. 2004-124333 discloses a spinning machine, which includes a spinning device, a yarn slack eliminating device (a yarn accumulating device), and a yarn sucking device (a suction device).
The yarn slack eliminating device is arranged downstream of the a delivery roller, and includes a yarn slack eliminating roller (a yarn accumulating roller) which can wind a yarn around an outer peripheral surface thereof. The yarn slack eliminating roller is rotated by an electric motor, and winds a yarn (a spun yarn), which is fed continuously from the spinning device, around the outer peripheral surface thereof to temporarily accumulate the yarn to prevent a yarn slackening, which generates during a yarn splicing operation.
The yarn sucking device is arranged between the spinning device and the yarn slack eliminating roller. A yarn sucking opening is formed on the yarn sucking device, which generates suction airflow at the yarn sucking opening. The yarn sucking device has a function for sucking and removing the yarn on the yarn accumulating roller when a yarn breakage occurs at downstream of the yarn slack eliminating device.
Next, a description will be made on removing the yarn on the yarn slack eliminating roller when the yarn breakage occurs at downstream of the yarn slack eliminating device. During a normal winding operation, by applying tension to the yarn accumulated temporarily on the yarn slack eliminating roller by the winding device, the yarn is unwound downstream and wound into a package by a winding device. However, since the winding device cannot apply tension to the yarn on the yarn slack eliminating roller when yarn breakage occurs at downstream of the yarn slack eliminating device (between the yarn slack eliminating device and the winding device), the yarn remains on the yarn slack eliminating roller.
Therefore, when yarn breakage occurs at downstream of the yarn slack eliminating device, following process is performed to remove the yarn on the yarn slack eliminating roller in the spinning machine described in Japanese Unexamined Patent Application Publication No. 2004-124333 . That is, when yarn breakage is detected, rotation of the yarn slack eliminating roller is stopped, and the yarn slack eliminating roller is rotated backward. Then, the yarn is cut off at upstream of the yarn slack eliminating roller (between the yarn slack eliminating roller and the spinning device), and is sucked by the yarn sucking device. As described above, the yarn remaining on the yarn slack eliminating roller can be sucked and removed by the yarn sucking device.
However, since the spinning machine described in Japanese Unexamined Patent Application Publication No. 2004-124333 rotates the yarn slack eliminating roller backward at a constant speed and for a constant period of time which are empirically determined, it was necessary to reconfigure a rotational speed and a rotational time for rotating the yarn slack eliminating roller backward whenever spinning conditions were changed. Moreover, the empirically-determined values may be inaccurate, and there were cases where the yarn slack eliminating roller is rotated excessively.
In addition, there may be a case in which the yarn unwound by rotating the yarn slack eliminating roller backward is entangled with the vicinity of the yarn slack eliminating roller. Since an operation for sucking and removing the yarn by the yarn sucking device cannot be continued when there is such entanglement of the yarn, an operator was required to resolve the entanglement of the yarn by hand. Accordingly, the entanglement caused a tremendous time loss in a spinning operation.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above-described circumstances, and it is an object of the present invention to provide a spinning machine which can efficiently remove a spun yarn remaining on a yarn accumulating roller.
According to an aspect of the present invention, the spinning machine includes a yarn accumulating roller, a driving motor, and a control section. The yarn accumulating roller temporarily accumulates the spun yarn produced by the spinning machine by winding the spun yarn around an outer peripheral surface thereof and rotating. The driving motor drives and rotates the yarn accumulating roller. When it is necessary to unwind the spun yarn wound around the yarn accumulating roller, the control section carries out a first control to control the driving motor to rotate the yarn accumulating roller in an opposite direction from a direction in which the yarn accumulating roller is rotated during a winding operation. After carrying out the first control, the control section carries out a second control to control the driving motor to rotate the yarn accumulating roller in the opposite direction from the direction in which the yarn accumulating roller is rotated during the winding operation at a speed which is higher than a rotational speed during the first control. Further, the control section carries out a control to temporarily increase a backward rotational speed of the yarn accumulating roller during the second control.
Accordingly, even when the spun yarn is entangled with the vicinity of the yarn accumulating roller before and after the yarn accumulating roller is rotated backward, the spun yarn entangled with the vicinity of the yarn accumulating roller can be spun off by centrifugal force by temporarily increasing the backward rotational speed of the yarn accumulating roller. Therefore, an operator does not need to remove the above-described entanglement of the spun yarn by hand, and a spinning operation by the spinning machine can be performed efficiently.
In the above-described spinning machine, it is preferable that the control section carries out a third control after the second control to control the driving motor to rotate the yarn accumulating roller in the direction in which the yarn accumulating roller is rotated during the winding operation. Accordingly, the spun yarn, which has not been removed during backward rotation and has remained on the yarn accumulating roller, can be spun off by rotating the yarn accumulating roller in the direction in which the yarn accumulating roller is rotated during the winding operation. Therefore, the operator does not need to remove the above-described spun yarn by hand, and the spinning operation by the spinning machine can be performed efficiently.
In the above-described spinning machine, it is preferable that in the second control, according to a spinning speed, the control section changes at least one of the rotational speed of the yarn accumulating roller, an amount of rotation of the yarn accumulating roller, and a time for which the yarn accumulating roller is rotated. Accordingly, since an amount of the spun yarn wound around the yarn accumulating roller can be estimated based on the spinning speed, the spun yarn wound around the yarn accumulating roller can be unwound from the yarn accumulating roller without excessively rotating the yarn accumulating roller.
It is preferable that the spinning machine includes an accumulated amount sensor which detects whether an accumulated amount of the spun yarn accumulated on the yarn accumulating roller is at least a prescribed amount or less than the prescribed amount. Accordingly, when removing the spun yarn remaining on the yarn accumulated roller, the accumulated amount sensor can detect that an accumulated amount of the spun yarn changes from at least a preset amount to less than the preset amount. Consequently, the accumulated amount sensor can detect whether or not the spun yarn has been unwound from the yarn accumulating roller by backward rotation of the yarn accumulating roller. In addition, an amount of the yarn to be accumulated on the yarn accumulating roller can be controlled and kept appropriately during the spinning operation.
In the above-described spinning machine, it is preferable that the control section proceeds from the first control to the second control when the accumulated amount sensor detects that the accumulated amount of the spun yarn accumulated on the yarn accumulating roller is less than the prescribed amount. Accordingly, after the accumulated amount sensor detects that the spun yarn remaining on the yarn accumulating roller has started to be unwound, the rotational speed of the yarn accumulating roller can be increased by the second control. Consequently, the spun yarn can be prevented from being entangled with various portions that has occurred due to the high-speed rotation of the yarn accumulating roller under a state in which the spun yarn has failed to be unwound from the yarn accumulating roller. Therefore, a time required for removing the entangled yarn can be significantly reduced.
In the above-described spinning machine, it is preferable that the control section controls to stop the rotation of the yarn accumulating roller in the second control when the accumulated amount sensor detects that the accumulated amount of the spun yarn on the yarn accumulating roller is at least the prescribed amount. Accordingly, even when the spun yarn is wound around the yarn accumulating roller in a backward direction due to an influence of the backward rotation, the accumulated amount sensor detects that the spun yarn is wound in the backward direction and the rotation of the yarn accumulating roller can be promptly stopped. Therefore, an impact when the spun yarn fails to be unwound from the yarn accumulating roller can be low: e.g., it is possible to prevent a large amount of the yarn from being wound around the yarn accumulating roller.
In the above-described spinning machine, in the first control, when the rotational amount of the yarn accumulating roller reaches a prescribed number or when a prescribed period of time elapses, in case the accumulated amount sensor does not detect that the accumulated amount of the spun yarn accumulated on the yarn accumulating roller is less than the prescribed amount (i.e. in case the accumulated amount sensor detects that the accumulated amount of the spun yarn accumulated on the yarn accumulating roller is at least the prescribed amount), it is preferable that the control section controls to stop the rotation of the yarn accumulating roller. Accordingly, the accumulated amount sensor can detect that the spun yarn does not start to be unwound from the yarn accumulating roller, and the rotation of the yarn accumulating roller can be stopped. Consequently, it is possible to prevent the spun yarn from being rotated around the yarn accumulating roller for a long period of time and to lower a possibility in which the yarn is entangled with the vicinity of the yarn accumulating roller.
It is preferable that the spinning machine includes a suction device which can generate suction airflow at a suction opening arranged near the outer peripheral surface of the yarn accumulating roller. Accordingly, the spun yarn wound around the yarn accumulating roller can be removed promptly when being unwound. Therefore, it is possible to prevent the unwound yarn from being wound again around the yarn accumulating roller.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a front view illustrating an overall structure of a spinning frame.
Fig. 2 is a longitudinal sectional view of the spinning frame.
Fig. 3 is a block diagram illustrating a main structure of the spinning frame.
Fig. 4 is a longitudinal sectional view of a yarn accumulating device.
Fig. 5 is an external perspective view of the yarn accumulating device.
Fig. 6 is a flowchart describing detection of a yarn breakage or the like, and a first control.
Fig. 7 is a perspective view illustrating a state in which the yarn accumulating roller is rotated backward under a first speed.
Fig. 8 is a perspective view illustrating a state immediately before the yarn accumulating roller starts to be rotated backward under a second speed.
Fig. 9 is a flowchart describing a second control.
Fig. 10 is a perspective view illustrating a state in which the yarn accumulating roller is rotated backward under a third speed.
Fig. 11 is a flowchart describing a third control.
Fig. 12 is a longitudinal sectional view illustrating a state in which upper yarn and lower yarn are caught by a suction pipe and a suction mouth.
Fig. 13 is a longitudinal sectional view illustrating a state when the upper yarn and the lower yarn are guided to a splicer.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Next, by referring to the drawings, a description will be made on a spinning frame (a spinning machine) 1 according to an embodiment of the present invention. In the followings, "upstream" and "downstream" refer to an upstream side and a downstream side in a travelling direction of a yarn during a spinning operation, respectively.
The spinning frame 1 as the spinning machine illustrated in Fig. 1 includes a plurality of units (spinning units 2) arranged next to one another. The spinning frame 1 includes a yarn splicing cart 3, a blower box 80, and a motor box 5.
As illustrated in Fig. 1, each spinning unit 2 includes a draft device 7, a spinning device 9, a yarn accumulating device 12, a lower yarn sensor (a disconnection detecting section) 31, and a winding device 13 as main components, which are arranged in this order from upstream to downstream. The draft device 7 is arranged near an upper end of a frame 6 of the spinning frame 1. The spinning device 9 spins a fiber bundle 8, which is fed from the draft device 7. After passing through a yarn clearer 52 which will be described later, a spun yarn 10 fed from the spinning device 9 is fed by the yarn accumulating device 12 and is wound by the winding device 13 into a package 45.
The draft device 7 drafts a sliver 15 to producing the fiber bundle 8. As illustrated in Fig. 2, the draft device 7 includes four rollers which are a back roller 16, a third roller 17, a middle roller 19 provided with an apron belt 18, and a front roller 20. Such rollers are connected to motors (not illustrated in the drawings). The draft device 7 can be driven by driving such motors, and a drafting operation in the draft device 7 can be stopped by stopping driving of such motors. Moreover, the driving and the stopping of such motors are controlled by a unit controller (a control section) 60 as illustrated in Fig. 3.
A detailed structure of the spinning device 9 is not illustrated in the drawings; however, the present embodiment adopts a pneumatic type which applies twists to the fiber bundle 8 by whirling airflow. By generating the whirling airflow inside the spinning device 9, the spun yarn 10 can be produced by the spinning device 9. Further, by stopping generation of the whirling airflow inside the spinning device 9, production of the spun yarn 10 by the spinning device 9 can be also stopped. In addition, as illustrated in Fig. 3, the unit controller 60 controls the generation and the stoppage of the whirling airflow.
The yarn accumulating device 12 is located downstream of the spinning device 9. The yarn accumulating device 12 has a pulling function, a slack preventing function, and a tension adjusting function. The pulling function is a function in which the yarn accumulating device 12 applies prescribed tension to the spun yarn 10 and pulls the spun yarn 10 from the spinning device 9. The slack preventing function is a function in which the yarn accumulating device 12 accumulates the spun yarn 10 fed from the spinning device 9 and prevents a yarn slackening during a yarn splicing operation performed by the yarn splicing cart 3 or the like. The tension adjusting function is a function in which the yarn accumulating device 12 adjusts tension of the spun yarn 10 such that change in tension on the winding device 13 side is prevented from propagating to the spinning device 9 side. As illustrated in Fig. 2, the yarn accumulating device 12 includes a yarn accumulating roller 21, a yarn hooking member 22, an upstream guide 23, an electric motor (a driving motor) 25, a downstream guide 26, and an accumulated amount sensor 27.
The yarn hooking member 22 is formed capable of being engaged with (hooking) the spun yarn 10. Under a state in which the yarn hooking member 22 is engaged with the spun yarn 10, the yarn hooking member 22 can guide the spun yarn 10 to an outer peripheral surface of the yarn accumulating roller 21 by rotating integrally with the yarn accumulating roller 21.
The yarn accumulating roller 21 can accumulate the spun yarn 10 by winding the spun yarn 10 around the outer peripheral surface thereof. The yarn accumulating roller 21 is driven and rotated by the electric motor 25. The yarn accumulating roller 21 is rotated such that the spun yarn 10, which has been guided to the outer peripheral surface of the yarn accumulating roller 21 by the yarn hooking member 22, is wound around the yarn accumulating roller 21 so as to tighten the yarn accumulating roller 21, and such a spun yarn 10 pulls the spun yarn 10 located upstream of the yarn accumulating device 12. Accordingly, the spun yarn 10 can be continuously pulled out from the spinning device 9.
The accumulated amount sensor 27 detects whether an accumulated amount of the spun yarn 10 accumulated on the yarn accumulating roller 21 is at least a prescribed amount or less than the prescribed amount in a non-contact manner. The accumulated amount sensor 27 transmits the detected accumulated amount of the spun yarn 10 to the unit controller 60.
The upstream guide 23 is located slightly upstream of the yarn accumulating roller 21. The upstream guide 23 functions as a guiding member which appropriately guides the spun yarn 10 to the outer peripheral surface of the yarn accumulating roller 21. Further, the upstream guide 23 functions as twist prevention which prevents twists of the spun yarn 10 transmitted from the spinning device 9 from propagating downstream of the upstream guide 23.
The downstream guide 26 is located slightly downstream of the yarn accumulating roller 21. The downstream guide 26 restricts an orbit of the spun yarn 10 which is swung by the rotating yarn hooking member 22. Accordingly, the downstream guide 26 guides the spun yarn 10 while stabilizing a travelling route of the spun yarn 10 located downstream.
A suction device 30 is located near the yarn accumulating roller 21. A connection tube 30a is connected to the suction device 30. The connection tube 30a is connected to a blower (not illustrated in the drawings), which is provided in the blower box 80. In such a structure, suction airflow can be generated in the suction device 30.
The yarn clearer (a yarn defect detecting device) 52 is located at front side of the frame 6 of the spinning frame 1 and at a position between the spinning device 9 and the yarn accumulating device 12. Before being wound by the yarn accumulating device 12, the spun yarn 10 fed by the spinning device 9 passes through the yarn clearer 52. The yarn clearer 52 monitors thickness of the travelling spun yarn 10. When detecting a yarn defect in the spun yarn 10, the yarn clearer 52 transmits a yarn defect detection signal to the unit controller 60. A cutter 57 is provided near the yarn clearer 52. The cutter 57 cuts off the spun yarn 10 when the package 45 is fully wound or the like.
As illustrated in Fig. 1 and Fig. 2, the yarn splicing cart 3 includes a splicer (a yarn splicing device) 43, a suction pipe 44, and a suction mouth 46. When a yarn breakage or a yarn cut occurs in one spinning unit 2, the yarn splicing cart 3 travels on a rail 41 fixed to the frame 6 to such a spinning unit 2, stops in front of such a spinning unit 2, and performs the yarn splicing operation.
The suction pipe 44 can swing around a shaft in a vertical direction. The suction pipe 44 sucks and catches a yarn end (an upper yarn) fed from the spinning device 9, and guides the yarn end to the splicer 43. The suction mouth 46 can swing around the shaft in a vertical direction. The suction mouth 46 sucks and catches a yarn end (a lower yarn) from the package 45 supported by the winding device 13, and guides the yarn end to the splicer 43. Although a detailed structure of the splicer 43 is not described, the upper yarn is spliced with the lower yarn by twisting each yarn end together by whirling airflow.
The lower yarn sensor 31 is located at a position between the yarn accumulating device 12 and the winding device 13. The lower yarn sensor 31 detects whether or not the spun yarn 10 exists at such a position. A lower yarn detection signal detected by the lower yarn sensor 31 is transmitted to the unit controller 60.
The winding device 13 includes a cradle arm 71 which is supported in a manner that the cradle arm 71 can be swung around a supporting shaft 70. The cradle arm 71 can support a bobbin 48 for winding the spun yarn 10 in a manner that the bobbin 48 can be rotated.
The winding device 13 includes a winding drum 72 and a traverse device 75. The winding drum 72 is driven while making contact with an outer peripheral surface of the bobbin 48 or an outer peripheral surface of the package 45, which is formed by winding the spun yarn 10 around the bobbin 48. The traverse device 75 includes a traverse guide 76 which can be engaged with the spun yarn 10. In such a structure, by driving the winding drum 72 by an electric motor (not illustrated in the drawings) while reciprocating the traverse guide 76 by a driving mechanism (not illustrated in the drawings), the package 45 making contact with the winging drum 72 is rotated, and the spun yarn 10 is wound into the package 45 while being traversed.
Next, by referring to Fig. 4 and Fig. 5, a detailed structure of the yarn accumulating device 12 will be described. The yarn accumulating roller 21 is a roller member formed of abrasion-resistant material. The yarn accumulating roller 21 is fixed to a motor shaft 25a of the electric motor 25. A side of an outer peripheral surface 21a of the yarn accumulating roller 21 where the yarn hooking member 22 is provided will be referred to as a tip end, and a side where the electric motor 25 is provided will be referred to as a base end. The outer peripheral surface 21a of the yarn accumulating roller 21 includes a base-end taper portion 21b, a cylindrical portion 21c, and a tip-end taper portion 21d arranged in this order from the base end to the tip end thereof.
The cylindrical portion 21c slightly tapers towards a tip end thereof, and also is flatly connected (without difference in level) with the taper portions 21b and 21d at both ends. The accumulated amount sensor 27 (not illustrated in Fig. 5) faces the cylindrical portion 21c. The accumulated amount sensor 27 detects an accumulated amount of the yarn wound around the yarn accumulating roller 21, and transmits the detected accumulated amount of the yarn to the unit controller 60. Specifically, the accumulated amount sensor 27 monitors a detecting position P1 illustrated in Fig. 5 (a range indicated by a chain line in Fig. 5). When the spun yarn 10 is wound around at the detecting position P1, an output from the accumulated amount sensor 27 to the unit controller 60 is turned ON and an accumulated amount detection signal is output. Meanwhile, when the spun yarn 10 is not wound around at the detecting position P1 and the cylindrical portion 21c is exposed, the accumulated amount detection signal is not output from the accumulated amount sensor 27 to the unit controller 60. That is, the output from the accumulated amount sensor 27 to the unit controller 60 is turned OFF.
Each of the base-end taper portion 21b and the tip-end taper portion 21d has a slightly tapered shape with a larger diameter at a corresponding end surface side. On the outer peripheral surface 21a of the yarn accumulating roller 21, the base-end taper portion 21b smoothly moves the supplied spun yarn 10 from a larger diameter portion to a smaller diameter portion towards the cylindrical portion 21c so as to orderly wind the spun yarn 10 around a surface of the cylindrical portion 21c. The tip-end taper portion 21d prevents a sloughing phenomenon in which the wound spun yarn 10 sloughs off all at once when unwinding the spun yarn 10 towards a downstream side. The tip-end taper portion 21d also has a function of sequentially rewinding the spun yarn 10 from the smaller diameter portion to the larger diameter portion at the end surface side so as to smoothly feed the spun yarn 10.
The suction device 30 is located near the yarn accumulating roller 21. The suction device 30 includes a suction pipe 30c formed in a pipe shape. One end of the suction pipe 30c, which is an open end, is provided with a suction opening 30b to generate suction airflow. The suction opening 30b is located near the outer peripheral surface of the yarn accumulating roller 21, and is located so as to be close to a base-end end portion of the yarn accumulating roller 21. In such a structure, the spun yarn 10 wound around a base-end portion of the yarn accumulating roller 21 is subjected to an influence of the suction airflow generated by the suction device 30. Further, the suction pipe 30c is connected with the connection tube 30a. Accordingly, fiber waste and a waste yarn sucked from the suction opening 30b are removed via the connection tube 30a, and are finally collected and discarded in a prescribed place.
Driving of the electric motor 25 (including a direction in which the electric motor 25 is driven) and stoppage thereof are controlled by the unit controller 60 as illustrated in Fig. 3. Accordingly, the unit controller 60 can control driving of the yarn accumulating roller 21 or the like. During a normal winding operation of the package, the unit controller 60 drives and rotates the yarn accumulating roller 21 in a rotational direction during the normal winding operation (a first direction) at a constant speed (a first rotational speed). Accordingly, the spun yarn 10 is wound around the yarn accumulating roller 21 at a constant speed, and the spun yarn 10 is pulled from the spinning device 9 at a constant speed by being pulled by the wound spun yarn 10.
In addition, in the followings, rotating the yarn accumulating roller 21 in the rotational direction during the normal winding operation will be simply referred to as forward rotation, and rotating the yarn accumulating roller 21 in an opposite direction from the normal winding operation (a second direction) will be referred to as backward rotation.
As illustrated in Fig. 4 and Fig. 5, the yarn hooking member 22 located on a tip end of the yarn accumulating roller 21 is arranged coaxially with the yarn accumulating roller 21. The yarn hooking member 22 includes a flyer axis 33 and a flyer 38 fixed to a tip end of the flyer axis 33.
The flyer axis 33 is supported relatively rotatable with respect to the yarn accumulating roller 21. A permanent magnet is mounted on one of the flyer axis 33 and the yarn accumulating roller 21, and a magnetic hysteresis member is mounted on the other thereof. A resistance torque is generated against the rotation of the yarn hooking member 22 relative to the yarn accumulating roller 21 by such magnetic mechanisms. The yarn hooking member 22 rotates accompanying rotation of the yarn accumulating roller 21 by the resistance torque. Accordingly, the yarn hooking member 22 and the yarn accumulating roller 21 rotate integrally. Meanwhile, when force that surpasses the resistance torque is applied to the yarn hooking member 22, the yarn hooking member 22 can rotate relatively with respect to the yarn accumulating roller 21.
The flyer 38 is curved appropriately toward the outer peripheral surface 21a of the yarn accumulating roller 21, and is formed in a shape in which the flyer 38 can be engaged with the spun yarn 10 (hook the spun yarn 10). Under a state in which the yarn is not wound around on the yarn accumulating roller 21, when the flyer 38 integrally rotates forward with the yarn accumulating roller 21, the flyer 38 is engaged with the spun yarn 10. Then, the spun yarn 10 engaged with the rotating flyer 38 is swung around by such a flyer 38, and is guided to and wound around the outer peripheral surface of the yarn accumulating roller 21 which is rotating forward.
As illustrated in Fig. 5, when the spun yarn 10 is wound around the outer peripheral surface of the yarn accumulating roller 21, friction force acts between the spun yarn 10 and the yarn accumulating roller 21. Accordingly, under such a state, when the yarn accumulating roller 21 rotates forward at a constant speed (the first rotational speed) in the first direction, force to pull the spun yarn 10 located upstream of the yarn accumulating roller 21 acts, and the spun yarn 10 can be pulled from the spinning machine 9 at a constant speed.
Next, a description will be made on a state of the spun yarn 10 wound around the yarn accumulating roller 21 which is rotated forward. The spun yarn 10 which has passed through the upstream guide 23 is guided from a base end of the yarn accumulating roller 21 to the outer peripheral surface 21a, and is wound around the cylindrical portion 21c a plurality of times. By being newly wound around the base end of the yarn accumulating roller 21 accompanying the forward rotation of the yarn accumulating roller 21, the spun yarn 10 wound around the cylindrical portion 21c is fed gradually from the base end of the yarn accumulating roller 21 to the tip end thereof. Then, the spun yarn 10, which is pulled from a tip end of the outer peripheral surface 21a, passes through the flyer 38, and is fed downward via the downstream guide 26.
In addition, as illustrated in Fig. 5, under a state in which the spun yarn 10 is wound around the yarn accumulating roller 21, when force is applied to pull the spun yarn 10 engaged with the flyer 38 downstream, force to attempt to rotate the yarn hooking member 22 so as to unwind the spun yarn 10 from the tip end of the yarn accumulating roller 21 is applied to the flyer 38. Accordingly, if yarn tension at downstream of the yarn accumulating device 12 (yarn tension between the yarn accumulating device 12 and the winding device 13) is strong enough to surpass the resistance torque, the yarn hooking member 22 rotates independently from the yarn accumulating roller 21 and the spun yarn 10 is gradually unwound from the tip end of the yarn accumulating roller 21 via the flyer 38.
Meanwhile, when the yarn tension at downstream of the yarn accumulating device 12 is not strong enough to surpass the resistance torque, the yarn hooking member 22 rotates integrally with the yarn accumulating roller 21. In such a case, the yarn hooking member 22 operates so as to prevent the spun yarn 10 from being unwound from the tip end of the rotating yarn accumulating roller 21.
As described above, when the downstream tension of the spun yarn 10 increases, the yarn accumulating device 12 operates to unwind the spun yarn 10 from the yarn accumulating roller 21. When the downstream tension of the spun yarn 10 decreases (when the spun yarn 10 is likely to slacken), the yarn accumulating device 12 operates to stop unwinding of the spun yarn 10 from the yarn accumulating roller 21. Accordingly, the yarn accumulating device 12 can eliminate slackening of the spun yarn 10 and apply appropriate tension to the spun yarn 10.
The yarn accumulating device 12 eliminates the slackening of the spun yarn 10 also during the yarn splicing operation. That is, during the yarn splicing operation, although a winding operation performed by the winding device 13 is stopped, the spun yarn 10 is continuously fed from the spinning device 9. As a result, the slackening of the spun yarn 10 is generated if the spun yarn 10 is left as it is. Therefore, the slackening of the spun yarn 10 is prevented by winding the spun yarn 10 around the yarn accumulating roller 21.
In addition, the yarn hooking member 22 operates so as to absorb change in the tension of the spun yarn 10 between the yarn accumulating device 12 and the winding device 13 as described above. Accordingly, the change in the tension of the spun yarn 10 can be prevented from influencing the spun yarn 10 between the spinning device 9 and the yarn accumulating device 12. The spun yarn 10 can be pulled from the spinning device 9 at a more steady speed by the yarn accumulating device 12 having the above-described structure.
Next, a description will be made on a control to be performed by the unit controller 60 in case the spun yarn 10 wound around the yarn accumulating roller 21 needs to be removed due to the yarn breakage or the like that has occurred at downstream of the yarn accumulating device 12 in the spinning frame 1 according to the present embodiment. The control includes a first control, a second control, and a third control. In the followings, the number of times the yarn accumulating roller 21 has been rotated from a prescribed point of time will be simply referred to as a rotational amount.
First, by referring to Fig. 6, Fig. 7, and Fig. 8, among a series of control performed by the unit controller 60, a description will be made on a control performed after detection of a yarn breakage or the like until the first control is performed. Fig. 6 is a flowchart describing detection of the yarn breakage or the like, and the first control. Fig. 7 is a perspective view illustrating a state in which the yarn accumulating roller 21 is rotated backward under a first speed. Fig. 8 is a perspective view illustrating a state immediately before the yarn accumulating roller 21 starts to be rotated backward under a second speed.
During the spinning operation, when the yarn breakage occurs at downstream of the yarn accumulating device 12 (between the yarn accumulating device 12 and the winding device 13) or when the splicer 43 fails in the yarn splicing operation, the winding device 13 cannot apply tension to the spun yarn 10 on the yarn accumulating roller 21. Accordingly, the spun yarn 10 cannot be unwound downstream from the yarn accumulating roller 21.
Such a yarn breakage or yarn splicing failure is detected by the lower yarn sensor 31. That is, when the lower yarn sensor 31 does not detect the spun yarn 10 for a prescribed period of time (e.g. approximately one second), the unit controller 60 determines that it is impossible to continue the winding operation since the yarn is cut off between the yarn accumulating device 12 and the winding device 13 (step S101). When a determination is made that the yarn breakage or the like has occurred, the unit controller 60 promptly controls to stop the drafting operation of the draft device 7 and a spinning operation of the spinning device 9, or the like to cut the spun yarn 10 (step S102).
Even after the spun yarn 10 is cut, the unit controller 60 controls the yarn accumulating roller 21 to continue to rotate forward (rotate in the first direction). Accordingly, a yarn end cut off by stopping the spinning device 9 or the like is around the yarn accumulating roller 21. Then, the unit controller 60 proceeds to the first control (step S103).
In the first control, by stopping forward rotation of the electric motor 25 and by driving the electric motor 25 in a direction in which the electric motor 25 is rotated backward (in the second direction), the unit controller 60 controls to rotate the yarn accumulating roller 21 backward (step S104). The backward rotation of the yarn accumulating roller 21 is performed under the first speed which is relatively low speed (the first rotational speed).
The suction opening 30b of the suction device 30 is located near the base end of the yarn accumulating roller 21, and suction airflow is generated at the suction opening 30b. When being wound around the yarn accumulating roller 21, the yarn end of the spun yarn 10, which has been cut off by stopping the spinning operation of the spinning device 9 or the like, is wound from the base end of the yarn accumulating roller 21. Therefore, such yarn end of the spun yarn 10 is sucked by the suction opening 30b. Even when the yarn end is not sucked by the suction opening 30b at this point of time, the first speed is relatively low and the yarn end is moderately rotated in a radial direction at the base end of the yarn accumulating roller 21. Accordingly, the yarn end is subjected to an influence of the suction airflow and sucked by the suction opening 30b in most cases. In addition, Fig. 7 illustrates a state immediately before the yarn end is sucked by the suction opening 30b.
Since the spun yarn 10 was wound from the base end of the yarn accumulating roller 21 when the yarn accumulating roller 21 was rotated forward, the spun yarn 10 is unwound from the base end of the yarn accumulating roller 21 if the yarn accumulating roller 21 is rotated backward (rotated in the second direction). As described above, when the yarn accumulating roller 21 is rotated backward under a state in which the yarn end is sucked by the suction operation 30b, the spun yarn 10 accumulated on the yarn accumulating roller 21 is sequentially unwound from the base end of the yarn accumulating roller 21. The spun yarn 10 is unwound from the yarn accumulating roller 21, and the spun yarn 10 remaining on the yarn accumulating roller 21 is sequentially sucked by the suction device 30.
As described above, the accumulated amount sensor 27 (not illustrated in Fig. 7) is located at a position facing the base end of the yarn accumulating roller 21. The unit controller 60 carries out the control according to a presence or an absence of the accumulated amount detection signal which is output from the accumulated amount sensor 27 (whether an output is ON or OFF) (step S105).
In the followings, a detailed description will be made. In Fig. 7, since the spun yarn 10 is wound around the yarn accumulating roller 21 at the detecting position P1, the accumulated amount detection signal is output from the accumulated amount sensor 27 to the unit controller 60. Meanwhile, when the spun yarn 10 is unwound from the base end of the yarn accumulating roller 21 and the spun yarn 10 at the detecting position P1 is unwound as illustrated in Fig. 8, the accumulated amount detection signal is not output from the accumulated amount sensor 27 to the unit controller 60. When the accumulated amount detection signal is not output from the accumulated amount sensor 27, the unit controller 60 determines that unwinding of the spun yarn 10 from the yarn accumulating roller 21 is successful and proceeds to the second control. Moreover, the spun yarn 10 may be entangled with the flyer 38 on the yarn accumulating roller 21 or the like before and after the yarn accumulating roller 21 is rotated backward, and Fig. 8 illustrates such a state.
In the first control, when the rotational amount of the yarn accumulating roller 21 after the start of the first control reaches a prescribed number, or when a prescribed period of time elapses after the start of the first control, in case the accumulated amount detection signal continues to be output from the accumulated amount sensor 27, it is determined that the spun yarn 10 is not unwound from the yarn accumulating roller 21 (the spun yarn 10 is not sucked by the suction opening 30b). In such a case, the unit controller 60 stops the rotation of the yarn accumulating roller 21 by controlling to stop the driving of the electric motor 25 (step S106).
Next, the second control will be described by referring to Fig. 9 and Fig. 10. Fig. 9 is a flowchart describing the second control. Fig. 10 is a perspective view illustrating a state in which the yarn accumulating roller 21 is rotated backward under a third speed.
After proceeding to the second control, the unit controller 60 controls to increase a rotational speed of the electric motor 25 and to rotate the yarn accumulating roller 21 backward under the second speed (a second rotational speed) which is higher than the first speed (step S107). As described above, by rotating the yarn accumulating roller 21 at high speed, the spun yarn 10 remaining on the yarn accumulating roller 21 can be unwound from the yarn accumulating roller 21 at a high speed. Accordingly, the second rotational speed is set to a speed at which the spun yarn 10 on the yarn accumulating roller 21 is nearly floated by centrifugal force.
Also in the second control, the accumulated amount detection signal is output at all times from the accumulated amount sensor 27 to the unit controller 60 (the output from the accumulated amount sensor 27 is ON) (step S108). The unit controller 60 does not carry out any control when the output from the accumulated amount sensor 27 remains to be OFF. However, when the output from the accumulated amount sensor 27 is turned ON (step S108, step S111, or step S114), the unit controller 60 determines that the spun yarn 10 unwound from the yarn accumulating roller 21 is wound again around the yarn accumulating roller 21 and controls to stop the backward rotation of the yarn accumulating roller 21. Further, the spun yarn 10 is wound again around the yarn accumulating roller 21 in an opposite direction from the normal operation (i.e. from the tip end of the yarn accumulating roller 21 to the base end thereof).
The unit controller 60 counts the rotational amount and rotating time of the yarn accumulating roller 21 after the start of the backward rotation of the yarn accumulating roller 21 under the second speed (step S109). When the rotational amount of the yarn accumulating roller 21 or a backward rotational time of the yarn accumulating roller 21 counted by the unit controller 60 exceeds a prescribed value, the unit controller 60 controls to increase the rotational speed of the electric motor 25 and to rotate the yarn accumulating roller 21 backward under the third speed which is higher that the second speed (step S110).
Even when the spun yarn 10 is entangled with the flyer 38, the entangled spun yarn 10 can be spun off by centrifugal force as illustrated in Fig. 10 by temporarily rotating the yarn accumulating roller 21 under the third speed.
The third speed is extremely higher than a speed at which the spun yarn 10 is sucked by the suction device 30. Therefore, if the spun yarn 10 continues to be unwound from the yarn accumulating roller 21 under the third speed, an operation for sucking the spun yarn 10 performed by the suction device 30 cannot keep up with the third speed and the spun yarn 10 is accumulated near the yarn accumulating roller 21. In such a case, the spun yarn 10 is entangled with each portion in the vicinity of the yarn accumulating roller 21. Accordingly, a rotational amount or a rotational time of the accumulating roller 21 under the third speed is set to be relatively short. In a same manner as step S109, the unit controller 60 counts the rotational amount of the yarn accumulating roller 21 or the backward rotational time of the yarn accumulating roller 21 from the start of the backward rotation of the yarn accumulating roller 21 under the third speed (step S112). When the rotational amount of the yarn accumulating roller 21 or the backward rotational time of the yarn accumulating roller 21 exceeds the prescribed value, the unit controller 60 controls driving of the electric motor 25 to rotate the yarn accumulating roller 21 backward under the second speed again (step S113).
The unit controller 60 carries out the above-described (second) backward rotation of the yarn accumulating roller 21 under the second speed until the rotational amount or the backward rotational time from when the yarn accumulating roller 21 is rotated backward under the second speed exceeds the prescribed value, and then proceeds to the third control. The unit controller 60 counts the rotational amount of the yarn accumulating roller 21 or the backward rotational time of the yarn accumulating roller 21 in such a case as well as in cases of step S109 and step S112 (step S115).
In addition, in the second control, the unit controller 60 automatically calculates the rotational amount or the backward rotational time of the yarn accumulating roller 21 according to sett conditions. For example, a method for such calculation will be considered as follows.
That is, an expected maximum value of a length of the spun yarn 10 remaining on the yarn accumulating roller 21 is previously estimated. In general, the length of the spun yarn 10 wound around the yarn accumulating roller 21 reaches its maximum immediately after the yarn splicing operation. The reason is because, as described above, the yarn accumulating roller 21 is rotated in a forward direction even during the yarn splicing operation and continues to wind the spun yarn 10 travelling from upstream thereof. Meanwhile, since the spun yarn 10 is not supplied to downstream of the yarn accumulating roller 21 during the yarn splicing operation, the spun yarn 10 which is supplied from the spinning device 9 during the yarn splicing operation (for approximately one second in the present embodiment) accumulates on the yarn accumulating roller 21.
Further, as described above, until the prescribed period of time (e.g. approximately one second) elapses after the occurrence of the yarn breakage or the like, a determination is not made that such a yarn breakage or the like has occurred. Accordingly, it is considered that the spun yarn 10, which is supplied from the spinning device 9 during such prescribed period of time, is wound further around the yarn accumulating roller 21.
Furthermore, a spinning speed is preset, and a time required for the yarn splicing operation and a time required until a determination is made that the yarn breakage has occurred can also be preset. Accordingly, the expected maximum value of the length of the spun yarn 10 can be calculated by multiplying a sum of the above-described times by the spinning speed. The unit controller 60 decides a prescribed value for each of the rotational speed of the yarn accumulating roller 21, the rotational amount of the yarn accumulating roller 21, and the rotational time of the yarn accumulating roller 21 so that all of the spun yarn 10 wound around the yarn accumulating roller 21 can be unwound even when the length of such spun yarn 10 is equal to the maximum value.
Next, the third control will be described by referring to Fig. 11 through Fig. 13. Fig. 11 is a flowchart describing the third control. Fig. 12 is a longitudinal sectional view illustrating a state in which the upper yarn and the lower yarn are caught by the suction pipe 44 and the suction mouth 46. Fig. 13 is a longitudinal sectional view illustrating a state when the upper yarn and the lower yarn are guided to the splicer 43.
All of the spun yarn 10 wound around the yarn accumulating roller 21 is supposedly removed when the second control has been completed. However, the spun yarn 10, which has failed to be removed from the yarn accumulating roller 21 during the backward rotation under the third speed, may still be caught on the flyer 38 or the like. Therefore, in order to swing off such spun yarn 10 from the flyer 38 or the like, the unit controller 60 controls to rotate the yarn accumulating roller 21 forward (step S116).
The forward rotation of the yarn accumulating roller 21 is continued until the rotational amount or the rotational time from the start of the forward rotation under such a speed exceeds a prescribed value (step S117). The prescribed value is set to be relatively small. The unit controller 60 transmits a control signal to the yarn splicing cart 3, controls the yarn splicing cart 3 to travel to the front of the spinning unit 2, and controls to start the yarn splicing operation (step S118). First, the unit controller 60 controls the suction mouth 46 to swing to the vicinity of a surface of the package 45 (refer to Fig. 12), controls to generate suction airflow at a suction opening on the suction mouth 46, and controls to rotate the package 45 backward by the winding device 13. Accordingly, the yarn end (the lower yarn) is drawn from the outer peripheral surface of the package 45, and the lower yarn is sucked and caught by the suction mouth 46.
Next, while rotating the package 45 backward by the winding device 13, the unit controller 60 controls the suction mouth 46 to swing upward to guide the lower yarn to the splicer 43 under a state in which the suction mouth 46 is sucking the lower yarn (refer to Fig. 13). When the lower yarn is guided to the splicer 43, rotation of the package 45 is stopped.
Before or after a swinging movement of the suction mouth 46, the unit controller 60 controls the suction pipe 44 to swing to the vicinity of a downstream side of the spinning device 9 (refer to Fig. 12). The unit controller 60 controls to re-drive the spinning device 9 or the like to restart the spinning operation, and controls to generate suction airflow at the suction pipe 44 to catch the yarn end (the upper yarn) at the spinning device 9 side. Then, by swinging the suction pipe 44 downward while continuing such suction, the unit controller 60 controls to pull the spun yarn 10 from the spinning device 9 and to guide the spun yarn 10 to the splicer 43 (refer to Fig. 13).
When the splicing operation performed by the splicer 43 is completed, the normal winding operation performed by the winding device 13 is restarted.
As described above, the spinning frame 1 according to the present embodiment includes the yarn accumulating roller 21, the electric motor 25, and the unit controller 60. The yarn accumulating roller 21 temporarily accumulates the spun yarn 10 produced by the spinning device 9 by winding the spun yarn 10 around the outer peripheral surface thereof and rotating. The driving motor 25 drives and rotates the yarn accumulating roller 21. When it is necessary to unwind the spun yarn 10 wound around the yarn accumulating roller 21, the unit controller 60 carries out the first control to control the electric motor 25 to rotate the yarn accumulating roller 21 backward. Then, the unit controller 60 carries out the second control to control the electric motor 25 to rotate the yarn accumulating roller 21 backward at a speed which is higher than the rotational speed during the first control. The unit controller 60 carries out a control to temporarily increase a backward rotational speed of the yarn accumulating roller 21 during the second control.
Accordingly, even when the spun yarn 10 is entangled with the flyer 38 or the like before and after the yarn accumulating roller 21 is rotated backward, the spun yarn 10 entangled with the flyer 38 or the like can be spun off by centrifugal force by increasing the backward rotational speed of the yarn accumulating roller 21 to the third speed such that the backward rotational speed of the yarn accumulating roller 21 is increased temporarily. Therefore, an operator does not need to remove the entangled spun yarn 10 by hand, and the spinning operation in the spinning frame 1 can be performed efficiently.
In the spinning frame 1 according to the present embodiment, the unit controller 60 carries out the third control after the second control to control the electric motor 25 to rotate the yarn accumulating roller 21 forward. Accordingly, by rotating the yarn accumulating roller 21 in a direction in which the spun yarn 10 is wound around, the spun yarn 10 which has failed to be removed during the backward rotation of the yarn accumulating roller 21 can be spun off from the yarn accumulating roller 21 or the like. Therefore, the operator does not need to remove the unnecessary yarn entangled around the yarn accumulating roller 21 by hand, and the spinning operation in the spinning frame 1 can be performed efficiently.
In the spinning frame 1 according to the present embodiment, the unit controller 60 changes the rotational speed of the yarn accumulating roller 21, the amount of rotation of the yarn accumulating roller 21, and the time for which the yarn accumulating roller 21 is rotated, in the second control, according to the spinning speed. Accordingly, without rotating the yarn accumulating roller 21 excessively, the spun yarn 10 wound around the yarn accumulating roller 21 can be unwound.
The spinning frame 1 according to the present embodiment includes the accumulated amount sensor 27 which detects whether the accumulated amount of the spun yarn 10 accumulated on the yarn accumulating roller 21 is at least the prescribed amount or less than the prescribed amount. Accordingly, when removing the spun yarn 10 remaining of the yarn accumulating roller 21, the accumulated amount sensor 27 can detect that that the amount of the spun yarn 10 remaining on the yarn accumulated roller 21 has changed from at least a preset amount to less than the preset amount. Consequently, the accumulated amount sensor 27 can detect whether or not the spun yarn 10 wound around the yarn accumulating roller 21 has been unwound by the backward rotation of the yarn accumulating roller 21. Further, during the spinning operation, the amount of the yarn to be accumulated on the yarn accumulating roller 21 can be controlled and kept appropriately by detecting the amount of the spun yarn 10 accumulated on the yarn accumulating roller 21 by the accumulated amount sensor 27.
In the spinning frame 1 according to the present embodiment, the unit controller 60 proceeds from the first control to the second control when the accumulated amount sensor 27 detects that the accumulated amount of the spun yarn 10 accumulated on the yarn accumulating roller 21 is less than the prescribed amount. Accordingly, after the accumulated amount sensor 27 detects that the spun yarn 10 wound around the yarn accumulating roller 21 starts to be unwound, the unit controller 60 can increase the rotational speed of the yarn accumulating roller 21 during the second control. Consequently, the spun yarn 10 can be prevented from being entangled with various portions due to the yarn accumulating roller 21 being rotated at a high speed under a state in which the spun yarn 10 has failed to be unwound from the yarn accumulating roller 21. Therefore, a time required for removing the entangled spun yarn 10 can be significantly reduced.
In the spinning frame 1 according to the present embodiment, in the second control, when the accumulated amount sensor 27 detects that the accumulated amount of the spun yarn 10 on the yarn accumulating roller 21 is at least the prescribed amount, the unit controller 60 controls to stop the rotation of the yarn accumulating roller 21. Accordingly, even when the spun yarn 10 is wound around the yarn accumulating roller 21 in a backward direction due to an influence of the backward rotation of the yarn accumulating roller 21, the accumulated amount sensor 27 can detect such a state and the unit controller 60 can control to promptly stop the rotation of the yarn accumulating roller 21. Therefore, an impact when the spun yarn 10 fails to be unwound from the yarn accumulating roller 21 can be made small: e.g., it is possible to prevent a large amount of the spun yarn 10 from being wound around the yarn accumulating roller 21.
In the spinning frame 1 according to the present embodiment, in the first control, even when the rotational amount or the rotational time of the yarn accumulating roller 21 exceeds a prescribed value, in case the accumulated amount sensor 27 does not detect that the accumulated amount of the spun yarn 10 accumulated on the yarn accumulating roller 21 is less than the prescribed amount (i.e. in case the accumulated amount sensor 27 continuously detects that the accumulated amount of the spun yarn 10 accumulated on the yarn accumulating roller 21 is at least the prescribed amount), the unit controller 60 controls to stop the rotation of the yarn accumulating roller 21. Accordingly, the accumulated amount sensor 27 can detect that the spun yarn 10 does not start to be unwound from the yarn accumulating roller 21, and then the unit controller 60 can control to stop the rotation of the yarn accumulating roller 21. Consequently, it is possible to prevent the spun yarn 10 from being rotated around the yarn accumulating roller 21 for a long period of time and to lower a possibility in which the spun yarn 10 is entangled with the flyer 38 or the like.
The spinning frame 1 according to the present embodiment includes the suction device 30 which can generate suction airflow at the suction opening 30b arranged near the outer peripheral surface of the yarn accumulating roller 21. Accordingly, when the spun yarn 10 wound around the yarn accumulating roller 21 is unwound, such unwound spun yarn 10 can be removed promptly. Therefore, it is possible to prevent the unwound spun yarn 10 from being wound again around the yarn accumulating roller 21.
While preferred embodiments of the present invention have been described as above, the structure can be modified as below, for example.
In the second control, although speed, which changes in two stages including the second speed and the third speed, is used as the backward rotational speed of the yarn accumulating roller 21, the speed to be changed can be changed in three stages, four stages or more as long as the yarn accumulating roller 21 is temporarily rotated backward at high speed. Further, timing for temporarily rotating the yarn accumulating roller 21 at high speed can be also changed arbitrarily.
Instead of a structure in which the yarn splicing cart 3 performs the yarn splicing operation, each spinning unit 2 may include a structure for performing a yarn splicing operation.
A method for applying torque to the yarn hooking member 22 and the yarn accumulating roller 21 is not limited to a magnetic mechanism as described above, and frictional force or an electromagnetic mechanism can be used.
The yarn hooking member 22 and the yarn accumulating roller 21 are not necessarily provided to be relatively rotatable. For example, like a slack eliminating device disclosed in Japanese Unexamined Patent Application Publication No. 2004-124333 , a notch section formed on a slack eliminating roller can serve as a yarn hooking section.
A shape of the suction device 30 is not limited to the above-described shape. For example, instead of a structure in which the suction opening 30b is made on a tip end of the suction pipe 30c, a suction opening may be formed on a tip end of a square tube shaped member.

Claims

A spinning machine comprising:
a spinning device (9) which produces spun yarn from a fiber bundle,

a yarn accumulating roller (21) which temporarily accumulates the spun yarn produced by the spinning device (9) by winding the spun yarn around an outer peripheral surface thereof and rotating in a first direction,

a driving motor (25) which drives and rotates the yarn accumulating roller (21),

a winding device (13) which winds the spun yarn into a package,

a disconnection detecting section (31) which detects a disconnection of the spun yarn between the yarn accumulating roller (21) and the winding device (13) over a prescribed period of time, and

a control section (60) which, when the disconnection detecting section (31) detects that the spun yarn is disconnected over the prescribed period of time, carries out a first control to control the driving motor (25) to rotate the yarn accumulating roller (21) under a first rotational speed in a second direction, which is an opposite direction from the first direction, and then carries out a second control to control the driving motor (25) to rotate the yarn accumulating roller (21) under a second rotational speed, which is higher than the first rotational speed, in the second direction, wherein during the second control, to temporarily increase the second rotational speed of the yarn accumulating roller (21).
The spinning machine according to claim 1, characterized in that the disconnection detecting section (31) detects that the spun yarn between the yarn accumulating roller (21) and the winding device (13) is disconnected by detecting a yarn breakage between the yarn accumulating roller (21) and the winding device (13) while the spun yarn is being produced by the spinning device (9)
The spinning machine according to claim 1, characterized by further comprising a yarn splicing device (43) which carries out a yarn splicing operation to splice a spun yarn from the spinning device (9) and a spun yarn from the winding device (13),
characterized in that the disconnection detecting section (31) detects that the spun yarn between the yarn accumulating roller (21) and the winding device (13) is disconnected by detecting that the yarn splicing operation by the yarn splicing device (43) has failed.
The spinning machine according to any one of claim 1 through claim 3, characterized in that the control section (60) carries out a third control after the second control to control the driving motor (25) to rotate the yarn accumulating roller (21) in the first direction.
The spinning machine according to any one of claim 1 through claim 4, characterized in that in the second control, according to a spinning speed of the spinning device (9), the control section (60) changes at least one of the second rotational speed of the yarn accumulating roller (21), an amount of rotation of the yarn accumulating roller (21), and a time for which the yarn accumulating roller (21) is rotated.
The spinning machine according to any one of claim 1 through claim 5, characterized by further comprising an accumulated amount sensor (27) which detects whether an accumulated amount of the spun yarn accumulated on the yarn accumulating roller (21) is at least a prescribed amount or less than the prescribed amount.
The spinning machine according to claim 6, characterized in that when the accumulated amount sensor (27) detects that the accumulated amount of the spun yarn accumulated on the yarn accumulating roller (21) is less than the prescribed amount, the control section (60) proceeds from the first control to the second control.
The spinning machine according to claim 6 or claim 7, characterized in that when the accumulated amount sensor (27) detects that the accumulated amount of the spun yarn on the yarn accumulating roller (21) is at least the prescribed amount, the control section (60) controls to stop the rotation of the yarn accumulating roller (21) in the second control.
The spinning machine according to any one of claim 6 though claim 8, characterized in that in the first control, when the rotational amount of the yarn accumulating roller (21) reaches a prescribed number or when a prescribed period of time elapses from start of the first control, in case the accumulated amount sensor (27) detects that the accumulated amount of the spun yarn accumulated on the yarn accumulating roller (21) is at least the prescribed amount, the control section (60) controls to stop the rotation of the yarn accumulating roller (21).
The spinning machine according to any one of claim 1 through claim 9, characterized by further comprising a suction device (30) that can generate suction airflow at a suction opening (30b) arranged near the outer peripheral surface of the yarn accumulating roller (21).