EP2808283B1

EP2808283B1 - Yarn winding machine

Info

Publication number: EP2808283B1
Application number: EP14162268.8A
Authority: EP
Inventors: Tomoyuki Ikkai
Original assignee: Murata Machinery Ltd
Current assignee: Murata Machinery Ltd
Priority date: 2013-05-31
Filing date: 2014-03-28
Publication date: 2016-05-18
Anticipated expiration: 2034-03-28
Also published as: CN104210894A; IN2014CH01255A; JP2014234256A; EP2808283A1

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a yarn winding machine equipped with a yarn pooling device. The present invention more particularly relates to control of a pooled yarn amount of the yarn winding machine.

2. Description of the Related Art

Spinning machines with a yarn pooling device (yarn slack removing device) arranged between a spinning device and a winding section are known in the art. For example, Japanese Patent Application Laid-open No. 2004-277949 (Patent Document 1) discloses this type of spinning machine.
Such a yarn pooling device includes a yarn pooling roller (yarn slack removing roller) that rotates with a yarn wound around its circumference. A small amount of pooled yarn (length of the yarn wound on the yarn pooling roller) leads to slippage between the yarn pooling roller and the yarn because of insufficient contact surface between the yarn pooling roller and the yarn. Therefore, the amount of pooled yarn wound on the yarn pooling roller needs to be greater than or equal to a predetermined amount. Minimizing the amount of yarn wound on the yarn pooling roller also minimizes the amount of yarn that is discarded during yarn joining. Hence, there have been ongoing endeavors to control the amount of pooled yarn (pooled amount) wound on the yarn pooling roller so as to maintain it within a predetermined range.
Specifically, the spinning machine disclosed in Patent Document 1 includes a sensor (switching member 54) that is capable of detecting whether the pooled yarn amount (slack amount) on the yarn pooling roller has exceeded a predetermined amount. The spinning machine disclosed in Patent Document 1 switches between a state in which a package is in contact with a rotary drum and a state in which the package is separated from the rotary drum, depending on an on/off state of the sensor, and thereby maintains the pooled yarn amount wound on the yarn pooling roller within a predetermined range. FIGS. 10A and 10B are graphs explaining how the pooled amount and the running speed of the yarn that is wound into the package change in the control disclosed in Patent Document 1.
In the spinning machine disclosed in Patent Document 1, because the running speed of the yarn wound into the package decreases/increases depending on the on/off state of the sensor (switching member 54), every time the sensor is turned on or off, the tension on the yarn being wound into the package varies greatly, leading to package faults, such as stitching and the like.
In the conventional control disclosed in Patent Document 1, the running speed of the yarn is merely decreased or increased without flexibility for exerting control in accordance with the situation.
EP 1 460 015 A1 describes a tension control and slack eliminating device for a yarn winder used to prevent the amount of slack from decreasing below a predetermined value during a yarn winding process executed by a spinning machine. During a winding process, when it is detected that the amount of slack in the yarn slack eliminating device decreases below a predetermined value, the package is separated from a rotating drum to reduce a winding speed to increase the amount of slack. At this time, the time for which the package remains separated is controlled in accordance with the winding diameter of the package to adjust the aspect of reduction of the winding speed. When the amount of slack is increased, the time for which the reduction of the winding speed is continued and the amount of speed reduction are adjusted taking the winding diameter of the package into account.
EP0 004 781 A1 describes a method and an apparatus for winding yarn being supplied from a constant speed source directly onto a cone. The yarn passes from the source to the cone via a storage device, and the speed of rotation of the cone is varied so as to keep the amount of yarn stored within a predetermined range. The storage device includes a drum around which the yarn is wound tangentially and from which the yarn is removed axially. The amount of yarn on the drum is sensed, and the speed of rotation of the cone varied accordingly.
US 4, 553, 709 A describes a yarn accumulator. A yarn is fed substantially tangentially from a feed station to the feed end of an accumulator roller of the yarn accumulator. The yarn is dischargeable from an exit end of the accumulator roller counter to the action of a restraining element through a yarn guide means arranged in prolongation of the axis of the accumulator roller.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a yarn winding machine allowing for a flexible yarn control.
This object is achieved by a yarn winding machine according to claim 1.
According to another aspect of the present invention, a yarn winding machine includes a yarn supplying section that supplies a yarn; a winding section that winds the yarn supplied by the yarn supplying section into a package while traversing the yarn; a yarn pooling device that is arranged between the yarn supplying section and the winding section and pools the yarn; a pooled-amount monitoring section that acquires a pooled amount of the yarn in the yarn pooling device as an analog amount; and a controller that performs a first control to adjust at least one of an entry speed, which is a running speed of the yarn entering the yarn pooling device, and an exit speed, which is the running speed of the yarn leaving the yarn pooling device, such that the pooled amount converges to a target value. The pooled-amount monitoring section is adapted to acquire the pooled amount from the entry speed, which is the running speed of the yarn (10) entering the yarn pooling device (22), and the exit speed.
With other words, the controller is adapted to adjust the entry speed and/or the exit speed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side view of a spinning unit during normal winding;
FIG. 2 is a side view of a state where a yarn has been disconnected between a yarn supplying section and a winding section;
FIG. 3 is a side view showing how ends of a disconnected yarn are sucked and caught;
FIG. 4 is a side view showing how the yarn is transported to a yarn joining device;
FIG. 5 is a side view showing how the yarn is hooked to a yarn hooking member;
FIG. 6 is a side view showing how a slack removal control is performed;
FIG. 7 is a block diagram of a unit controller;
FIG. 8A is a graph of an example that explains how a pooled amount changes, and FIG. 8B is a graph of an example that explains how an exit speed changes;
FIG. 9A is a graph of an example that explains how the pooled amount changes when a ribbon breaking control is performed in parallel with a pooled amount control, and FIG. 9B is a graph of an example that explains how the exit speed changes when the ribbon breaking control is performed in parallel with the pooled amount control; and
FIG. 10A is a graph of an example that explains how the pooled amount changes in a conventional control, and FIG. 10B is a graph of an example that explains how the exit speed changes in the conventional control.

DETAILED DESCRIPTION

Exemplary embodiments of a spinning machine (yarn winding machine) according to the present invention are explained in detail below with reference to the accompanying drawings.
The spinning machine includes a plurality of spinning units (yarn winding units) 2 arranged side by side and a not shown machine control device that centrally manages the spinning units 2. Each of the spinning units 2 winds a yarn (spun yarn 10) supplied from a yarn supplying section 5 by a winding section 26 to form a package 50.
The spinning machine includes a unit controller 12 capable of communicating with the machine control device. The unit controller 12 is a computer equipped with hardware, such as a microprocessor, and software, such a control program, and controls all the components of the spinning unit 2. The unit controller 12 can be provided individually for each spinning unit 2 or for each group of a plurality of the spinning units 2.
A structure of the spinning unit 2 is explained below. As shown in FIG. 1, the spinning unit 2 includes, from upstream to downstream, the yarn supplying section 5, a yarn pooling device 22, and the winding section 26. In this specification, the terms "upstream" and "downstream" are defined with reference to a running direction of the spun yarn 10 during normal winding. The term "during normal winding" refers to when the spun yarn 10 is in a continuous state between the yarn supplying section 5 and the winding section 26 and is being wound by the winding section 26.
In the spinning unit 2 according to the present embodiment, the yarn running direction is substantially horizontal upstream of the yarn pooling device 22 and slanting upward downstream of the yarn pooling device 22. A yarn path of the spun yarn 10 during winding bends significantly (by an angle greater than or equal to 90 degrees) at the yarn pooling device 22.
The yarn supplying section 5 supplies the yarn (spun yarn 10) to be wound by the winding section 26. The yarn supplying section 5 according to the present embodiment includes a drafting device 7, a spinning device 9, a delivery roller 21, and a nip roller 31.
The drafting device 7 stretches (drafts) a sliver 15 into a fiber bundle 8 of a predetermined fiber amount (or thickness). The drafting device 7 includes four draft rollers (namely, sequentially from upstream, a back roller 16, a third roller 17, a middle roller 19 stretched over which is a rubber apron belt 18, and a front roller 20) that are driven to rotate and four opposing rollers facing the four draft rollers, respectively. The sliver 15 is nipped between the rotating pairs of the draft roller and the opposing roller and transported to be drafted and formed into the fiber bundle 8.
The spinning device 9 is arranged immediately downstream of the front roller 20. The spinning device 9 twists the fiber bundle 8 supplied from the drafting device 7 to form the spun yarn 10. The spinning device 9 according to the present embodiment is an air spinning machine that produces a swirling airflow internally, and twists the fiber bundle 8 by subjecting it to the swirling airflow.
The delivery roller 21 that is driven to rotate at a predetermined speed and the nip roller 31 that can be brought into contact with or separated from the delivery roller 21 are arranged downstream of the spinning device 9. By nipping the spun yarn 10, which is discharged from the spinning device 9, between the delivery roller 21 and the nip roller 31 and driving the delivery roller 21 to rotate, the spun yarn 10 is sent downstream.
The spun yarn 10 is supplied to the winding section 26 by the yarn supplying section 5 having the above configuration (the drafting device 7, the spinning device 9, the delivery roller 21, and the nip roller 31).
The running speed (spinning speed) of the spun yarn 10 produced by the spinning device 9 is controlled so as to be maintained at a fixed value previously set by an operator. For example, the operator can set the spinning speed of each spinning unit 2 by operating the machine control device. The unit controller 12 automatically sets the rotation speed of the draft rollers 16, 17, 19, and 20 and the delivery roller 21 based on the set value of the spinning speed. In this manner, the spinning device 9 produces the spun yarn 10 at the spinning speed set by the operator. The spinning speed of the spinning device 9 according to the present embodiment is in the range of, for example, 250 m/min to 600 m/min.
The winding section 26 winds the spun yarn 10 on a winding tube 51 while traversing the spun yarn 10. The winding tube 51 with the spun yarn 10 wound around it is collectively called the package 50. The winding section 26 includes a cradle arm 52, a winding drum (rotary roller) (contact roller) 53, and an electric motor 14.
The cradle arm 52 includes bearings (supporting section) 55 that rotatably support the winding tube 51 of the package 50. The winding drum 53 is driven to rotate by the electric motor 14. A rotation speed of the electric motor 14 is controlled by the unit controller 12.
The cradle arm 52 is capable of bringing an outer circumferential surface of the package 50 supported by the bearings 55 into contact with an outer circumferential surface of the winding drum 53. The spun yarn 10 continues to be wound into the package 50 as the rotation of the winding drum 53 drives the package 50 to rotate while the package 50 is in contact with the winding drum 53. A not shown traverse groove is formed on the outer circumferential surface of the winding drum 53. The spun yarn 10 that is wound into the package 50 can be traversed to a predetermined width by this traverse groove.
The yarn pooling device 22 is arranged between the yarn supplying section 5 and the winding section 26. The yarn pooling device 22 includes a yarn pooling roller 41, an electric motor (driving section) 42 that drives the yarn pooling roller 41 to rotate, and a yarn hooking member 43.
The yarn pooling roller 41 is a cylindrical (or substantially cylindrical) member made of a metal. The spun yarn 10 can be pooled by being wound around the outer circumferential surface of the yarn pooling roller 41. The spun yarn 10 upstream of the yarn pooling roller 41 is wound around the outer circumferential surface of the yarn pooling roller 41 by causing the yarn pooling roller 41 with the spun yarn 10 wound thereon to be driven to rotate by the electric motor 42. A rotation speed of the electric motor 42 is controlled by the unit controller 12.
The running speed of the spun yarn 10 immediately upstream of the yarn pooling roller 41 (the spun yarn 10 between the yarn pooling device 22 and the yarn supplying section 5) shall be referred to as "entry speed" because it is the speed of the spun yarn 10 as the spun yarn 10 enters the yarn pooling device 22. The entry speed is equal to a circumferential speed of the yarn pooling roller 41 when no slippage occurs between the outer circumferential surface of the yarn pooling roller 41 and the spun yarn 10.
It is preferable that the entry speed of the spun yarn 10 headed for the yarn pooling device 22 is slightly higher than the spinning speed. When this is achieved, appropriate tension is applied on the spun yarn 10 between the yarn supplying section 5 and the yarn pooling device 22 and the spun yarn 10 can be tightly wound around the outer circumferential surface of the yarn pooling roller 41. The unit controller 12 controls the rotation speed of the electric motor 42 such that the circumferential speed (which is equal to or nearly equal to the entry speed) of the yarn pooling roller 41 is slightly higher than a set value of the spinning speed. Because the spinning speed is constant, the entry speed during normal winding is controlled so as to be constant.
Downstream of the yarn pooling roller 41, a regulating guide 62 is arranged on an extension line from a rotation axis of the yarn pooling roller 41. The regulating guide 62 guides the spun yarn 10 being unwound from the yarn pooling roller 41.
The spun yarn 10 pooled on the yarn pooling roller 41 is pulled in the downstream direction when the winding section 26 drives the package 50 to rotate and winds the spun yarn 10. As a result of this pulling, the spun yarn 10 pooled on the yarn pooling roller 41 is unwound from a downstream end portion of the yarn pooling roller 41 and wound into the package 50. The running speed of the spun yarn 10 that is unwound from the yarn pooling roller 41 and wound into the package 50 shall be referred to as "exit speed" because it is the speed of the spun yarn 10 as the spun yarn 10 exits the yarn pooling device 22.
The yarn hooking member 43 is arranged at the downstream end portion of the yarn pooling roller 41. The yarn hooking member 43 is configured to be coaxially rotatable relative to the yarn pooling roller 41. A not shown resistance member that applies a predetermined resistance torque is mounted on a rotation axis of the yarn hooking member 43 relative to the yarn pooling roller 41. The yarn hooking member 43 catches the spun yarn 10 being unwound from the downstream end portion of the yarn pooling roller 41.
Because of the resistance torque applied on the yarn hooking member 43, a predetermined tension is applied on the spun yarn 10 (the spun yarn 10 being unwound from the yarn pooling roller 41) caught by the yarn hooking member 43. In this manner, the yarn hooking member 43 applies the predetermined tension on the spun yarn 10 between the yarn pooling roller 41 and the winding section 26. By applying appropriate tension on the spun yarn 10, the unwinding of the spun yarn 10 from the yarn pooling roller 41 can be stabilized and also the spun yarn 10 can be tightly wound into the package 50 in the winding section 26.
In the yarn pooling device 22 having the above structure, the spun yarn 10 between the yarn supplying section 5 and the winding section 26 can be temporarily pooled by being wound on the outer circumferential surface of the yarn pooling roller 41. With this arrangement, for example, even if there is a variation in the winding speed in the winding section 26, it is absorbed by the yarn pooling device 22. Accordingly, the speed variation occurring in the winding section 26 can be prevented from adversely affecting the yarn supplying section 5. Consequently, a constant tension on the spun yarn 10 produced by the spinning device 9 can be maintained, and thereby the quality of the spun yarn 10 can be improved.
Next, a process of how the spun yarn 10 between the yarn supplying section 5 and the winding section 26 is disconnected for various reasons will be explained.
There are various reasons for disconnection of the spun yarn 10 between the yarn supplying section 5 and the winding section 26. For example, when a yarn defect (defective portion) is detected in the spun yarn 10, the spun yarn 10 is mandatorily cut by a cutter 24 so as to remove the yarn defect.
A yarn monitoring device 25 capable of detecting a yarn defect is arranged between the yarn pooling device 22 and the winding section 26. The yarn monitoring device 25 uses a not shown electrostatic capacitance type sensor to monitor a thickness of the running spun yarn 10. The yarn monitoring device 25 is capable of determining the running speed of the spun yarn 10 based on a detection result obtained at the sensor. The type of the sensor the yarn monitoring device 25 uses is not limited to electrostatic capacitance type. That is, a light transmissive type sensor can also be used by the yarn monitoring device 25 to monitor the thickness of the spun yarn 10. The yarn monitoring device 25 can also monitor presence/absence of a foreign matter in the spun yarn 10 as the yarn defect.
When an abnormal thickness is detected in the spun yarn 10, the yarn monitoring device 25 transmits a yarn defect detection signal to the unit controller 12. Upon receiving the yarn defect detection signal, the unit controller 12 drives the cutter 24 arranged near the yarn monitoring device 25 to cut the spun yarn 10 between the yarn pooling device 22 and the winding section 26.
Next, a process of how the winding is resumed after a disconnection of the spun yarn 10 occurs between the yarn supplying section 5 and the winding section 26 will be explained.
When a disconnection of the spun yarn 10 occurs between the yarn supplying section 5 and the winding section 26 for any reason, the unit controller 12 causes the spinning device 9 to suspend producing of the spun yarn 10. Because of the suspension of producing of the spun yarn 10 by the spinning device 9, the spun yarn 10 between the yarn supplying section 5 and the yarn pooling device 22 is disconnected. Consequently, the spun yarn 10 pooled by the yarn pooling device 22 is cut off from the yarn supplying section 5 and the winding section 26 (see FIG. 2).
In this situation, the unit controller 12 causes the yarn pooling roller 41 to rotate, causing the spun yarn 10 to unwind from an upstream end portion of the yarn pooling roller 41, and controls a residual-yarn removing device 30 to remove the unwound spun yarn 10 (residual-yarn removal process). The residual-yarn removing device 30 removes the spun yarn 10 wound on the yarn pooling roller 41 by suction.
Thereafter, the unit controller 12 performs a process of joining the spun yarn 10 from the yarn supplying section 5 (first yarn) and the spun yarn 10 from the winding section 26 (second yarn).
A yarn joining device 23 is arranged between the yarn monitoring device 25 and the yarn pooling device 22. The spinning unit 2 includes a first transporting device 27, which sucks and catches the first yarn and transports it to the yarn joining device 23, and a second transporting device 28, which sucks and catches the second yarn and transports it to the yarn joining device 23.
When the residual spun yarn 10 on the yarn pooling roller 41 is removed by the residual-yarn removal process, the unit controller 12 causes the spinning device 9 to resume the producing of the spun yarn 10. In addition, the unit controller 12 causes the first transporting device 27 to suck and catch the spun yarn 10 produced by the spinning device 9 (first yarn) (the state shown in FIG. 3). The unit controller 12 then causes the first transporting device 27 holding the first yarn to pivot and transport the first yarn to the yarn joining device 23 (the state shown in FIG. 4).
Around the same time, the unit controller 12 causes the package 50 to rotate in reverse so as to guide out the spun yarn 10 from the package 50 (second yarn) and the second transporting device 28 to suck and catch the second yarn (the state shown in FIG. 3). The unit controller 12 then causes the second transporting device 28, which is holding the second yarn, to pivot and transport the second yarn to the yarn joining device 23 (the state shown in FIG. 4).
The yarn joining device 23 joins an end of the first yarn transported by the first transporting device 27 and an end of the second yarn transported by the second transporting device 28 (yarn joining operation). In the present embodiment, the yarn joining device 23 is a splicer device that twists ends of yarns together by a swirling airflow generated by compressed air. However, the yarn joining device 23 is not limited to the above splicer device, but can be a mechanical knotter or the like, for example.
With the above structure, even if a disconnection of the spun yarn 10 occurs between the yarn supplying section 5 and the winding section 26, the first yarn and the second yarn can be joined (spliced) by the yarn joining device 23. Consequently, the continuity of the spun yarn 10 between the yarn supplying section 5 and the winding section 26 can be restored.
While the yarn joining device 23 is performing the yarn joining operation, the unit controller 12 stops the winding section 26 from rotating the package 50 and suspends the winding of the spun yarn 10 but allows the spinning device 9 to continue producing the spun yarn 10.
While the yarn joining device 23 is performing the yarn joining operation, the unit controller 12 performs a slack removal control (third control) by pooling the spun yarn 10 produced by the spinning device 9 in the yarn pooling device 22.
Specifically, once the yarn joining operation starts, the unit controller 12 hooks the spun yarn 10 produced by the spinning device 9 to the yarn hooking member 43 of the yarn pooling device 22 (FIG. 5). The spinning unit 2 includes a movable guide 61 that guides the spun yarn 10 up to the location of the yarn hooking member 43 (FIG. 5). In this state, the unit controller 12 drives the yarn pooling roller 41 to rotate. By the slack removal control (third control), the spun yarn 10 produced by the spinning device 9 is wound on the yarn pooling roller 41 of the yarn pooling device 22 during the yarn joining operation performed by the yarn joining device 23. The spun yarn 10 between the yarn supplying section 5 and the winding section 26 is therefore prevented from becoming slack during the yarn joining operation.
After completion of the yarn joining operation by the yarn joining device 23, the unit controller 12 causes the winding section 26 to resume the rotation of the package 50, and thereby resumes normal winding of the spun yarn 10 (FIG. 1).
Next, a characteristic structure of the present embodiment is explained.
The unit controller 12 performs a pooled amount control (first control) by controlling an amount of the spun yarn 10 (pooled amount) pooled in the yarn pooling device 22. FIG. 7 is a block diagram of the pooled amount control performed by the unit controller 12.
As explained with reference to Patent Document 1, the control of pooled amount in the yarn pooling device is also performed in the conventional device (FIG. 10A). In the conventional control, the pooled amount in the yarn pooling device is acquired from binary (digital) information in the form of an on/off state of the sensor. Consequently, only a rough control is possible, leading to a great variation in the winding tension of the yarn in the winding section.
In the present embodiment, the unit controller 12 functions as a pooled-amount monitoring section 33 that acquires the amount of the spun yarn 10 pooled in the yarn pooling device 22 (pooled amount) in the form of an analog amount.
The expression "to acquire in the form of an analog amount" in this specification is used to convey the meaning that a value that is finer than the digital (binary) value is obtained. Therefore, the expression "to acquire in the form of an analog amount" is also inclusive of the meaning "to acquire as discrete amounts in three or more steps" in addition to "to acquire a contiguous value steplessly". In either case, because the unit controller 12 is configured as a computer, it handles even the analog amount as a digital numerical data when using the amount in internal calculations.
The pooled-amount monitoring section 33 calculates the pooled amount from the difference between the speed of the spun yarn 10 entering the yarn pooling device 22 (entry speed) and the speed of the spun yarn 10 leaving the yarn pooling device 22 (exit speed).
The exit speed and the entry speed can be acquired by a suitable method. For example, a suitable sensor can be used to measure and acquire the exit speed or the entry speed. Alternatively, the entry speed or the exit speed can be estimated from the operating state of each part of the spinning unit 2.
For example, as mentioned above, the yarn monitoring device 25 according to the present embodiment detects the running speed of the spun yarn 10 being unwound from the yarn pooling roller 41 and wound into the package 50 (exit speed). The pooled-amount monitoring section 33 according to the present embodiment acquires the running speed detected by the yarn monitoring device 25 as the exit speed. Therefore, it can be said that the yarn monitoring device 25 functions as a speed measuring section.
As mentioned above, the circumferential speed of the yarn pooling roller 41 can be regarded as matching with the entry speed. The pooled-amount monitoring section 33 according to the present embodiment acquires the circumferential speed of the yarn pooling roller 41 as the entry speed.
As mentioned above, the unit controller 12 controls the electric motor 42 such that the circumferential speed of the yarn pooling roller 41 is slightly higher than the set value of the spinning speed, and maintains control information required for such a control. Therefore, the unit controller 12 acquires the circumferential speed of the yarn pooling roller 41 from the control information (set value of the spinning speed and the like) stored in the unit controller 12. Accordingly, the unit controller 12 is capable of acquiring the entry speed (which is equal to the circumferential speed of the yarn pooling roller 41) without any need for a dedicated sensor, etc.
The exit speed and the entry speed can be acquired as analog amounts. The pooled-amount monitoring section 33 acquires the amount of the spun yarn 10 (pooled amount) pooled in the yarn pooling device 22 as the analog amount by integrating the difference between the exit speed and the entry speed (integrated over time).
Because the exit speed and the entry speed acquired by the pooled-amount monitoring section 33 can include errors, the errors could accumulate as the differences between the exit speeds and the entry speeds accumulate. Therefore, the pooled-amount monitoring section 33 corrects the integrated value based on information obtained by a sensor and the like.
For example, the yarn pooling device 22 includes a yarn sensor (detecting section) 32 that is arranged near the outer circumferential surface of the yarn pooling roller 41. The yarn sensor 32 is turned on when the amount of the spun yarn 10 (pooled amount) wound on the yarn pooling roller 41 reaches a predetermined amount. The yarn sensor 32 is a reflection-type optical sensor and is capable of detecting by a noncontact manner that the pooled amount has reached the predetermined amount. A detection result obtained at the yarn sensor 32 is output to the unit controller 12.
Accordingly, the pooled-amount monitoring section 33 can determine that the pooled amount has reached the predetermined amount with the switching of the yarn sensor 32 between on and off. The pooled-amount monitoring section 33 resets the integrated value of the exit speed and the entry speed (pooled amount) to the predetermined value whenever the yarn sensor 32 switches between on and off.
Furthermore, in the residual-yarn removal process, the spun yarn 10 pooled on the yarn pooling roller 41 can be entirely removed. Therefore, the pooled-amount monitoring section 33 can judge when the pooled amount has reached zero. When the residual-yarn removal process is implemented by the unit controller 12, the pooled-amount monitoring section 33 resets the integrated value of the exit speed and the entry speed (pooled amount) to zero.
As explained above, the pooled-amount monitoring section 33 resets the integrated value of the exit speed and the entry speed (pooled amount) from the operating state of various sensors and/or the spinning unit 2. Consequently, the pooled-amount monitoring section 33 prevents accumulation of errors and acquires an accurate pooled amount.
Explained below is the pooled amount control (first control) performed based on the pooled amount acquired as explained above.
The unit controller 12 performs a feedback control such that the pooled amount acquired by the pooled-amount monitoring section 33 converges to a target value. A typical control such as a PI control or a PID control can be used to perform such a feedback control.
Various methods can be adopted for the pooled amount control of the pooled amount in the yarn pooling device 22. For example, a method in which the entry speed is adjusted or a method in which the exit speed is adjusted or a method in which both the entry speed and the exit speed are adjusted can be considered. However, as mentioned above, the entry speed in the spinning machine according to the present embodiment is constant. Therefore, the unit controller 12 according to the present embodiment controls the pooled amount by adjusting the exit speed. Specifically, taking the rotation speed of the electric motor 14 as an operation amount, the unit controller 12 performs the feedback control of the rotation speed of the electric motor 14 such that the pooled amount in the yarn pooling device 22 converges to the target amount.
The unit controller 12 performs the feedback control (pooled amount control) during the normal winding. In this manner, the pooled amount in the yarn pooling device 22 can be maintained to the target value during the normal winding.
However, adjustment of the exit speed is not possible (feedback control is not possible) during the slack removal control (third control) because the winding of the spun yarn 10 by the winding section 26 is suspended during the slack removal control. Therefore, the unit controller 12 does not perform the pooled amount control when the slack removal control is being performed.
However, the pooled-amount monitoring section 33 continues to acquire the pooled amount even while the slack removal control is being performed (in this case, the pooled amount can be calculated by regarding the exit speed as zero and integrating the entry speed). In this manner, the pooled-amount monitoring section 33 can determine the amount of the spun yarn 10 pooled in the yarn pooling device 22 during the slack removal control. Because the exit speed is zero during the slack removal control, the pooled amount in the yarn pooling device 22 increases with an elapse of time.
Once the slack removal control ends, the unit controller 12 causes the winding section 26 to resume winding of the spun yarn 10 and also resumes the pooled amount control.
FIG. 8A is a graph of an example that explains how the pooled amount changes when the pooled amount control is started after the end of the slack removal control. As explained above, the pooled amount in the yarn pooling device 22 increases during the slack removal control. Consequently, at the time the slack removal control ends, there is an increased pooled amount. Accordingly, in the initial state of the graph shown in FIG. 8A, the difference (deviation) between the pooled amount and the target value is large. When the unit controller 12 starts the pooled amount control (feedback control) in this state, the electric motor 14 is controlled based on a deviation that is large. Consequently, the electric motor 14 is drastically accelerated. As a result, the exit speed (running speed of the spun yarn 10 being wound into the package 50) increases drastically (FIG. 8B). In this manner, the pooled amount in the yarn pooling device 22 can be quickly converged to the target value. The period in which the pooled amount is brought closer to the target amount is called a "pooled-amount adjustment period".
As the pooled amount control continues, the deviation between the pooled amount and the target value becomes smaller, and accordingly, the exit speed gradually decreases (see FIG. 8B). Once the pooled amount reaches the target value, the pooled amount is controlled so as to be maintained at the target value. Consequently, a variation amount of the exit speed becomes small. The period in which the pooled amount is maintained at the target value is called a "pooled-amount maintenance period".
A ribbon breaking control (second control) performed by the unit controller 12 is explained next.
In the above Patent Document 1, it is pointed out that its third embodiment is advantageous in preventing occurrence of ribbon winding (overlapping of the freshly wound yarn with the yarn already wound into the package) due to slowing down of the package. This advantage is achieved in the control disclosed in Patent Document 1 because, as shown in FIG. 10B, a great variation in the running speed of the yarn being wound into the package causes the yarn tension to vary greatly, which in turn leads to a change in a traverse angle.
In the pooled amount control performed by the unit controller 12 according to the present embodiment, as shown in FIG. 8B, because the variation in the running speed (exit speed) of the spun yarn 10 being wound into the package 50 is small (particularly, in the pooled-amount maintenance period), there is only a small variation in the yarn tension. Therefore, the pooled amount control according to the present embodiment is not expected to have the advantage of preventing occurrence of ribbon winding.
Therefore, the unit controller 12 according to the present embodiment is configured so as to be able to perform the ribbon breaking control (second control), when required, in parallel with the pooled amount control (the ribbon breaking control can be performed while the pooled amount control is being performed). The ribbon breaking control is a control whereby the traverse angle is temporarily changed by varying the circumferential speed of the package 50 or the traverse speed or both. Ribbon winding can be prevented by changing the traverse angle.
The ribbon breaking control performed by the unit controller 12 according to the present embodiment is a control whereby slippage is caused between the package 50 and the winding drum 53 by a sudden temporary decrease in the rotation speed of the winding drum 53 (disturb control). The circumferential speed of the package 50 and the traverse speed temporarily change due to the sudden deceleration of the winding drum 53, leading to a temporary change in the traverse angle, and thereby preventing ribbon winding.
FIGS. 9A and 9B are graphs of an example that explain how the pooled amount changes when the ribbon breaking control is performed by the unit controller 12 according to the present embodiment. In the ribbon breaking control according to the present embodiment, because the rotation speed of the winding drum 53 is suddenly decreased, the exit speed decreases temporarily, leading to a temporary increase in the pooled amount. However, the pooled amount control is independently being performed in parallel with the ribbon breaking control. Therefore, because the pooled amount control is performed for every cycle of the disturb control, the pooled amount can be maintained at a value close to the target value.
The advantages of the present embodiment are explained below.
As explained above, in the conventional control (FIGS. 10A and 10B), the running speed of the yarn being wound into the package is increased or decreased based on the binary (digital) information about the on/off state of the sensor. That is, in the conventional process, the running speed of the yarn being wound into the package is varied digitally (FIG. 10B). Consequently, in the conventional control, the tension of the yarn being wound varies greatly, leading to package defects, such as stitching.
In the present embodiment, in contrast, the pooled amount is acquired as an analog amount and the rotation speed of the electric motor 14 is controlled by using this pooled amount as a feedback. Consequently, the running speed (exit speed) of the spun yarn 10 being wound into the package 50 can be changed smoothly (in an analog manner) (FIG. 8B). Therefore, compared to the conventional control, the tension on the spun yarn 10 being wound into the package 50 can be stabilized.
Particularly, in the pooled amount control according to the present embodiment, in the pooled-amount maintenance period after the pooled amount reaches the target value, the variation amount of the running speed (exit speed) of the spun yarn 10 being wound into the package 50 reduces. Consequently, the tension on the spun yarn 10 being wound into the package 50 can be made extremely stable. In this manner, package defects, such as stitching, can be avoided, and a high quality package 50 can be formed.
Furthermore, in the pooled amount control according to the present embodiment, because the amount of the spun yarn 10 wound on the yarn pooling roller 41 (pooled amount) is maintained at the target value, the contact surface area between the yarn pooling roller 41 and the spun yarn 10 can be adequately obtained. That is, the target value is the amount of the spun yarn 10 that is sufficient enough to ensure an adequate contact surface area between the yarn pooling roller 41 and the spun yarn 10. In this manner, because slippage between the outer circumferential surface of the yarn pooling roller 41 and the spun yarn 10 can be reliably prevented, an appropriate tension is applied on the spun yarn 10 by the yarn hooking member 43. In this context also, the tension on the spun yarn 10 being wound into the package 50 can be stabilized.
In the pooled amount control according to the present embodiment, when a large amount of the spun yarn 10 is pooled in the yarn pooling device 22 (when the deviation between the pooled amount and the target value is large), the exit speed is drastically accelerated to quickly bring the pooled amount closer to the target value (pooled-amount adjustment period). Therefore, a large amount of the spun yarn 10 can be prevented from remaining in the yarn pooling device 22 over a long period of time.
If a disconnection of the spun yarn 10 occurs between the yarn supplying section 5 and the winding section 26 in a state where a large amount of the spun yarn 10 is pooled in the yarn pooling device 22, the large amount of the spun yarn 10 pooled in the yarn pooling device 22 is disposed of by the residual-yarn removal process, resulting in poor efficiency.
In the control according to the present embodiment, because a large amount of the spun yarn 10 is prevented from remaining in the yarn pooling device 22 over a long period of time, there is a higher possibility of avoiding having to dispose of a large amount of the spun yarn 10. In this manner, production efficiency of the spinning unit 2 can be improved.
In the pooled amount control disclosed in Patent Document 1 (FIGS. 10A and 10B), because the running speed of the yarn being wound into the package varies greatly, ribbon winding is advantageously prevented. However, in this kind of method where the running speed of the yarn varies greatly, the circumferential speed of the package varies greatly, leading to difficulty in precisely controlling the traverse angle. Therefore, in the conventional pooled amount control (FIGS. 10A and 10B), ribbon winding is not necessarily prevented as planned.
In the present embodiment, when prevention of ribbon winding is necessary, the ribbon breaking control is performed in parallel with the pooled amount control. The exit speed varies temporarily when the ribbon breaking control is performed; however, the pooled amount control is performed in parallel (FIG. 9B). Therefore, in the present embodiment, even if the ribbon breaking control is performed, it is relatively easier to precisely control the traverse angle because the variation in the circumferential speed of the package 50 is suppressed to be low. The unit controller 12 according to the present embodiment can perform an accurate ribbon breaking control.
In the control disclosed in Patent Document 1, the traverse angle simply changes as a result of the control but cannot be changed as desired.
In contrast, in the present embodiment, even though the pooled amount control and the ribbon breaking control are performed in parallel, they are performed independently of each other. Because the unit controller 12 is capable of controlling the rotation speed of the winding drum 53 during the ribbon breaking control, the traverse angle can be changed as desired. In this manner, the spinning machine according to the present embodiment reliably prevents ribbon winding, and thereby further improves the quality of the package 50.
As explained above, the spinning machine according to the present embodiment includes the yarn supplying section 5, the winding section 26, the yarn pooling device 22, the pooled-amount monitoring section 33, and the unit controller 12. The yarn supplying section 5 supplies the spun yarn 10. The winding section 26 winds the spun yarn 10 supplied by the yarn supplying section 5 into the package 50 while traversing the spun yarn 10. The yarn pooling device 22 pools the spun yarn 10 between the yarn supplying section 5 and the winding section 26. The pooled-amount monitoring section 33 acquires the pooled amount of the spun yarn 10 in the yarn pooling device 22 as an analog amount. The unit controller 12 performs the pooled amount control to adjust the exit speed, which is the running speed, of the spun yarn 10 leaving the yarn pooling device 22 such that the pooled amount reaches the target value.
In this manner, by acquiring the pooled amount of the spun yarn 10 in the yarn pooling device 22 as an analog amount, the unit controller 12 can perform a feedback control so that the pooled amount converges to the target value. In this manner, the pooled amount can be stabilized and the running speed of the spun yarn 10 being wound by the winding section 26 can be precisely controlled. Consequently, drastic variation in the running speed of the spun yarn 10 can be suppressed. As a result, the tension on the spun yarn 10 being wound into the package 50 can be stabilized and a high quality package 50 can be formed.
Exemplary embodiments of the present invention were explained above. However, the above configuration can be modified, for example, as explained below.
In the spinning machine according to the above embodiments (FIGS. 1 to 6), the spun yarn 10 runs from bottom to top in a height direction of the machine. However, the present invention can also be applied to a configuration in which the spun yarn runs from top to bottom (for example, in the air spinning machine disclosed in Japanese Patent Application Laid-open No. 2010-77576 ).
The embodiments of the spinning machine in which the structure according to the present invention is applied are explained above. However, the present invention can also be widely applied to other yarn winding machines.
For example, the present invention can be applied to the automatic winder that includes a yarn supplying section, a winding section, and a yarn pooling device (accumulator) as disclosed in Japanese Patent Application Laid-open No. 2012-197135 . The yarn supplying section of the automatic winder is configured to enable a yarn supplying bobbin to be arranged therein and supplies the yarn that is unwound from the yarn supplying bobbin. The winding section of the automatic winder winds the yarn into the package while traversing the yarn, similar to the above embodiments. The accumulator of the automatic winder includes a rotary pooling section. The rotary pooling section is a roller shaped member that pools the yarn by winding the yarn on an outer circumferential surface thereof, similar to the yarn pooling roller 41 of the above embodiments. Therefore, in the automatic winder, the amount of yarn pooled in the accumulator (pooled amount) can be controlled by the pooled amount control according to the present invention.
In the automatic winder, the package winding is continued even if a yarn disconnection occurs between the yarn supplying section and the winding section. Consequently, a large amount of yarn is pooled in the accumulator (yarn pooling device). When the present invention is applied to the above-mentioned type of automatic winder, the process for quickly reducing the pooled yarn amount after the yarn joining operation (pooled-amount adjustment period of the above embodiments) can be omitted.
When the rotation of the rotary pooling section (yarn pooling roller) is stopped during the yarn joining operation, as mentioned in Japanese Patent Application Laid-open No. 2012-197135 , the unit controller 12 suspends the pooled amount control. However, it is preferable that even in this case, the pooled-amount monitoring section 33 continues to acquire the pooled amount. With this arrangement, the pooled amount during the yarn joining operation can be obtained. Consequently, the pooled amount control can be properly started after the yarn joining operation ends.
In the spinning machine according to the above embodiments, the spinning speed is constant and therefore, it is necessary to maintain a constant running speed (entry speed) of the spun yarn 10 wound by the yarn pooling roller 41. In the automatic winder as disclosed in Japanese Patent Application Laid-open No. 2012-197135 , it is not necessary to maintain a constant entry speed. Accordingly, when applying the present invention to this kind of automatic winder, during the pooled amount control, the controller can adjust the entry speed instead of or along with the exit speed.
The accumulator disclosed in Japanese Patent Application Laid-open No. 2012-197135 does not have a member equivalent to the yarn hooking member 43 of the above embodiments. Instead, in Japanese Patent Application Laid-open No. 2012-197135 , tension is applied on the yarn being unwound from the rotary pooling section by a tension applying device (second tensor) that is arranged between the accumulator and the winding section. In this manner, the yarn hooking member can be omitted from the configuration and another tension applying member can be arranged.
The yarn pooling device is not limited to a configuration where the yarn is pooled by winding the yarn around the outer circumferential surface of a rotating yarn pooling roller. Structures other than the yarn pooling roller, such as slack tube or compensator and the like are well known as devices for pooling yarn. These well-known structures can also be employed as the yarn pooling device. However, if it is a structure where the spun yarn 10 is wound around the outer circumferential surface of the yarn pooling roller 41, as in the present embodiment, pooling of a large amount of the spun yarn 10 can be realized in a compact structure. Particularly, when the speed at which the spun yarn 10 is supplied by the yarn supplying section 5 is high, it is preferable to use the configuration according to the present embodiment that enables pooling of a large quantity of the spun yarn 10.
In the above embodiments, the running speed detected by the yarn monitoring device 25 is acquired as the exit speed. However, the structure is not limited to the above. A sensor separate from the yarn monitoring device 25 can be arranged to detect the exit speed.
The exit speed (running speed of the spun yarn 10 being wound into the package 50) can also be roughly estimated from information about rotation of the package 50. For example, a rotation information acquiring section that acquires rotation information of the bearing 55 or the winding drum 53 can be arranged, and the exit speed can be roughly estimated based on the rotation information. The rotation information acquiring section can be a pulse emitting section that outputs a pulse signal every time the bearing 55 or the winding drum 53 rotates by a predetermined angle.
In the above case, the pooled-amount monitoring section 33 can acquire the rotation speed of the bearing 55 or the winding drum 53 by counting the number of pulse signals output in a predetermined period. The pooled-amount monitoring section 33 can then calculate the running speed of the spun yarn 10 being wound into the package 50 from the rotation speed. The pooled-amount monitoring section 33 can acquire the pooled amount taking the running speed calculated in the above-mentioned manner as the exit speed.
In this manner, a fairly accurate exit speed that is close to the actual value can be obtained from the rotation information of the bearing 55 or the winding drum 53. Therefore, the pooled-amount monitoring section 33 can determine the exit speed without the need for a dedicated sensor.
In the above embodiments, the circumferential speed of the yarn pooling roller 41 is set slightly higher than the set value of the spinning speed. However, depending on the spinning condition, the circumferential speed of the yarn pooling roller 41 may be set so as to match with the spinning speed. In such a case, the pooled-amount monitoring section 33 can use the set value of the spinning speed itself as the entry speed.
The entry speed can be acquired by a method other than that uses the set value of the spinning speed. For example, a detection sensor that detects the running speed of the spun yarn 10 between the yarn pooling device 22 and the yarn supplying section 5 can be arranged, and a detection value obtained by this sensor can be acquired as the entry speed.
In the above embodiments, the pooled amount is acquired as an analog amount from the exit speed and the entry speed. However, for example, a sensor that detects the amount of the spun yarn 10 wound on the outer circumferential surface of the yarn pooling roller 41 (pooled amount) in three or more steps can be arranged and the value detected by the sensor can be acquired as the pooled amount.
The winding section 26 according to the above embodiments has a configuration where the package 50 is in contact with the winding drum (rotary roller) 53, and the package 50 is rotated by driving the winding drum 53 to rotate. However, the configuration of the winding section 26 is not limited to the above. The package 50 can be directly driven to rotate.
In the winding section 26 according to the above embodiments, the traverse groove formed on the outer circumferential surface of the winding drum 53 is used for traversing the spun yarn 10. However, an arm-type traversing device can be used for traversing the spun yarn 10.
In the above embodiments, the first control, the second control, and the third control according to the present invention are called "pooled amount control", "ribbon breaking control", and "slack removal control", respectively. However, these are merely names given for convenience of explanation. The first control, the second control, and the third control are independent of each other. Therefore, the second control or the third control or both can be omitted.
The first control and the second control can be performed at all times during normal winding or only at a part of the period during normal winding. The third control can be performed at all times when no spun yarn 10 is being wound by the winding section 26 or only at a part of the period when no spun yarn 10 is being wound by the winding section 26.
According to an aspect of the present invention, a yarn winding machine includes a yarn supplying section, a winding section, a yarn pooling device, a pooled-amount monitoring section, and a controller. The yarn supplying section supplies a yarn. The winding section winds the yarn supplied by the yarn supplying section into a package while traversing the yarn. The yarn pooling device is arranged between the yarn supplying section and the winding section and pools the yarn. The pooled-amount monitoring section acquires a pooled amount of the yarn in the yarn pooling device as an analog amount. The controller performs a first control to adjust an exit speed, which is a running speed of the yarn leaving the yarn pooling device, such that the pooled amount converges to a target value.
By acquiring the pooled amount of the yarn in the yarn pooling device as an analog amount, the controller can perform a feedback control of the exit speed so that the pooled amount converges to the target value. In this manner, the pooled amount can be stabilized and the running speed of the yarn being wound by the winding section can be precisely controlled. Consequently, drastic variation in the running speed of the yarn can be suppressed. As a result, the tension on the yarn being wound into the package can be stabilized and a high quality package can be formed.
According to another aspect of the present invention, a yarn winding machine includes a yarn supplying section, a winding section, a yarn pooling device, a pooled-amount monitoring section, and a controller. The yarn supplying section supplies a yarn. The winding section winds the yarn supplied by the yarn supplying section into a package while traversing the yarn. The yarn pooling device is arranged between the yarn supplying section and the winding section and pools the yarn. The pooled-amount monitoring section acquires a pooled amount of the yarn in the yarn pooling device as an analog amount. The controller performs a first control to adjust at least one of an entry speed, which is a running speed of the yarn entering the yarn pooling device, and an exit speed, which is the running speed of the yarn leaving the yarn pooling device, such that the pooled amount converges to the target value.
With this arrangement, a feedback control of the entry speed can be performed instead of or in addition to the feedback control of the exit speed.
In the above yarn winding machine, preferably the pooled-amount monitoring section acquires the pooled amount from the entry speed, which is the running speed of the yarn entering the yarn pooling device, and the exit speed.
If the entry speed and the exit speed are known, the pooled-amount monitoring section can acquire the pooled amount in the yarn pooling device as an analog amount from the difference between the entry speed and the exit speed.
The above yarn winding machine further includes a detecting section that detects whether the pooled amount in the yarn pooling device is greater than or equal to a predetermined amount. The pooled-amount monitoring section corrects the pooled amount based on a detection result obtained at the detecting section.
When the pooled amount is acquired from the difference between the entry speed and the exit speed, reliability of the pooled amount acquired reduces with an elapse of time because of accumulation of errors in the entry speed and the exit speed. The pooled-amount monitoring section determines the correct pooled amount by correcting the acquired pooled amount based on the detection result obtained at the detecting section.
In the above yarn winding machine, preferably the pooled-amount monitoring section resets the acquired pooled amount to the predetermined amount when the detection result obtained at the detecting section changes.
With this arrangement, by suitably resetting the value of the acquired pooled amount, the pooled-amount monitoring section prevents the errors in the pooled amount from accumulating.
In the above yarn winding machine, preferably the yarn pooling device includes a yarn pooling roller that pools the yarn by winding the yarn on an outer circumferential surface thereof, and a driving section that drives the yarn pooling roller to rotate.
By pooling the yarn by winding the yarn on the outer circumferential surface of the yarn pooling roller, a compact configuration for pooling the yarn can be achieved.
In the above yarn winding machine, preferably the pooled-amount monitoring section acquires a circumferential speed of the yarn pooling roller as the entry speed.
In the yarn winding machine, because the yarn is pooled by winding the yarn around the rotating yarn pooling roller, the circumferential speed of the yarn pooling roller can be regarded as matching with the entry speed of the yarn. Therefore, a dedicated sensor for detecting the entry speed becomes unnecessary, and thereby, the structure of the yarn winding machine can be simplified.
In the above yarn winding machine, the yarn supplying section includes a spinning device that produces the yarn by spinning a fiber bundle. The pooled-amount monitoring section acquires the entry speed from a set value of a spinning speed at which the spinning device produces the yarn.
The spinning speed of the spinning device is normally a previously set constant speed. A dedicated sensor for detecting the entry speed becomes unnecessary if the entry speed could be acquired from the set value of the spinning speed. Consequently, the structure of the yarn winding machine can be simplified.
The above yarn winding machine further includes a speed measuring section that measures the running speed of the yarn running between the yarn pooling device and the winding section. The pooled-amount monitoring section acquires the running speed measured by the speed measuring section as the exit speed.
By actually measuring the exit speed, the pooled-amount monitoring section can correctly determine the exit speed. Because the pooled-amount monitoring section calculates the pooled amount from the correct information, the precision of a pooled amount control performed by the controller can be stabilized.
In the above yarn winding machine, the winding section includes a supporting section that rotatably supports the package and a contact roller that rotates while being in contact with the package. The winding section includes a rotation information acquiring section that acquires rotation information of the supporting section or the contact roller. The pooled-amount monitoring section uses the running speed of the yarn calculated from the rotation information as the exit speed.
A fairly accurate exit speed that is close to the actual value can be acquired from the rotation information of the supporting section or the contact roller. Therefore, the pooled-amount monitoring section can determine the exit speed without requiring a dedicated sensor.
In the above yarn winding machine, the controller performs, in parallel with the first control, a second control to vary at least one of a circumferential speed of the package and a traverse speed.
In the above pooled amount control, the second control (ribbon breaking control) can be performed correctly because the circumferential speed of the package does not vary greatly. Therefore, the package is formed while preventing the occurrence of ribbon winding and stabilizing the pooled amount in the yarn pooling device.
In the above yarn winding machine, the controller is configured to perform a third control to pool the yarn supplied by the yarn supplying section in the yarn pooling device in a period when no winding of the yarn is performed by the winding section. The first control performed when the winding of the yarn is started by the winding section after the end of the third control includes a pooled-amount adjustment period and a pooled-amount maintenance period. In the pooled-amount adjustment period, the pooled amount in the yarn pooling device is reduced till the pooled amount converges to the target value. In the pooled-amount maintenance period, the exit speed is reduced to a value that is less than the exit speed during the pooled-amount adjustment period, and the pooled amount is maintained at the target value.
Because a large amount of the yarn remains pooled in the yarn pooling device immediately after the third control ends, the controller quickly reduces the pooled amount of the yarn in the yarn pooling device till it converges to the target value. After the pooled amount converges to the target value, the controller exerts control to reduce the exit speed so as to maintain the pooled amount. In this manner, the exit speed can be varied according to the pooled amount by exertion of the first control.
The above yarn winding machine includes a yarn joining device and a removing device. The yarn joining device joins the yarn between the yarn pooling device and the winding section. The removing device removes the yarn remaining in the yarn pooling device when a yarn disconnection occurs between the yarn pooling device and the winding section.
Because the pooled amount in the yarn pooling device can be maintained at the target value by exertion of the first control, the amount of yarn that is discarded during yarn joining is minimized.
In the above yarn winding machine, it is preferable to further include a yarn hooking member that is arranged at a downstream end of the yarn pooling roller so as to be rotatable relative to the yarn pooling roller and that applies resistance to the yarn being unwound from the yarn pooling roller.
The yarn hooking member properly guides the yarn being unwound from the yarn pooling roller and also applies proper tension on the yarn. With this arrangement, the unwinding of the yarn from the yarn pooling roller can be stabilized.
In the above yarn winding machine, the yarn supplying section has a configuration that allows a yarn supplying bobbin to be arranged therein and supplies the yarn that is unwound from the yarn supplying bobbin.

Claims

A yarn winding machine comprising:
a yarn supplying section (5) adapted to supply a yarn (10);

a winding section (26) adapted to wind the yarn (10) supplied by the yarn supplying section (5) into a package (50) while traversing the yarn (10);

a yarn pooling device (22) arranged between the yarn supplying section (5) and the winding section (26) and adapted to pool the yarn (10);

a pooled-amount monitoring section (33) adapted to acquire a pooled amount of the yarn (10) in the yarn pooling device (22) as an analog amount; and

a controller (12) adapted to perform a first control to adjust at least one of an entry speed, which is a running speed of the yarn (10) entering the yarn pooling device (22), and an exit speed, which is the running speed of the yarn (10) leaving the yarn pooling device (22), such that the pooled amount converges to a target value,

characterized in that

the pooled-amount monitoring section (33) is adapted to acquire the pooled amount from the entry speed, which is the running speed of the yarn (10) entering the yarn pooling device (22), and the exit speed.
The yarn winding machine according to Claim 1, further comprising a detecting section (32) adapted to detect whether the pooled amount in the yarn pooling device (22) is greater than or equal to a predetermined amount,
wherein the pooled-amount monitoring section (33) is adapted to correct the acquired pooled amount based on a detection result obtained at the detecting section (32).
The yarn winding machine according to Claim 2, wherein the pooled-amount monitoring section (33) is adapted to reset the acquired pooled amount to the predetermined amount when the detection result obtained at the detecting section (32) changes.
The yarn winding machine according to any one of Claims 1 to 3, wherein the yarn pooling device (22) includes
a yarn pooling roller (41) adapted to pool the yarn (10) by winding the yarn (10) on an outer circumferential surface thereof; and
a driving section (42) adapted to drive the yarn pooling roller (41) to rotate.
The yarn winding machine according to Claim 4, wherein the pooled-amount monitoring section (33) is adapted to acquire a circumferential speed of the yarn pooling roller (41) as the entry speed.
The yarn winding machine according to Claim 4 or 5, further comprising a yarn hooking member (43) arranged at a downstream end of the yarn pooling roller (41) so as to be rotatable relative to the yarn pooling roller (41) and adapted to apply resistance to the yarn (10) being unwound from the yarn pooling roller (41).
The yarn winding machine according to any one of Claims 1 to 4, wherein the yarn supplying section (5) includes a spinning device (9) adapted to produce the yarn (10) by spinning a fiber bundle (8), and
the pooled-amount monitoring section (33) is adapted to acquire the entry speed from a set value of a spinning speed at which the spinning device (9) produces the yarn (10).
The yarn winding machine according to any one of Claims 1 to 7, further comprising a speed measuring section (25) adapted to measure the running speed of the yarn (10) running between the yarn pooling device (22) and the winding section (26),
wherein the pooled-amount monitoring section (33) is adapted to acquire the running speed measured by the speed measuring section (25) as the exit speed.
The yarn winding machine according to any one of Claims 1 to 7, wherein
the winding section (26) further includes
a supporting section (55) adapted to rotatably support the package (50), and

a contact roller (53) adapted to rotate while being in contact with the package (50),
the yarn winding machine further comprising a rotation information acquiring section adapted to acquire rotation information of the supporting section (55) or the contact roller (53),
wherein the pooled-amount monitoring section (33) is adapted to use the running speed of the yarn (10) calculated based on the rotation information as the exit speed.
The yarn winding machine according to any one of Claims 1 to 9, wherein the controller (12) is adapted to perform, in parallel with the first control, a second control to vary at least one of a circumferential speed of the package (50) and a traverse speed.
The yarn winding machine according to any one of Claims 1 to 10, wherein the controller (12) is configured to perform a third control to pool the yarn (10) supplied by the yarn supplying section (5) in the yarn pooling device (22) in a period when no winding of the yarn (10) is performed by the winding section (26), and
the first control performed when the winding of the yarn (10) is started by the winding section (26) after the end of the third control includes
a pooled-amount adjustment period in which the pooled amount in the yarn pooling device (22) is reduced till the pooled amount converges to the target value, and

a pooled-amount maintenance period in which the exit speed is reduced to a value that is less than the exit speed during the pooled-amount adjustment period, and the pooled amount is maintained at the target value.
The yarn winding machine according to any one of Claims 1 to 11, further comprising:
a yarn joining device (23) adapted to join the yarn (10) at a position between the yarn pooling device (22) and the winding section (26); and

a removing device (30) adapted to remove the yarn (10) remaining in the yarn pooling device (22) when a yarn disconnection occurs between the yarn pooling device (22) and the winding section (26).
The yarn winding machine according to any one of Claims 1 to 6, wherein the yarn supplying section (5) has a configuration that allows a yarn supplying bobbin to be arranged therein, and adapted to supply the yarn that is unwound from the yarn supplying bobbin.