TECHNICAL FIELD
[0001] The present invention relates to a yarn winding apparatus. More specifically, the
present invention relates to reverse rotation control of a package during a yarn joining
operation performed by a yarn winding unit of the yarn winding apparatus.
BACKGROUND ART
[0002] There is a conventional well-known yarn winding apparatus having a winding section
which winds a yarn fed from a yarn feeding section so as to form a package. Generally,
this kind of yarn winding apparatus includes a winding unit which is provided with
a yarn catching and guiding device and a yarn joining device. The yarn catching and
guiding device catches a yarn end of one of divisional yarns into which a yarn is
divided between the yarn feeding section and the winding section. The yarn joining
device joins another yarn end to the yarn end guided by the yarn catching and guiding
device. Patent Document 1 discloses a winding unit serving as a package forming unit
of this kind of yarn winding apparatus.
[0003] The winding unit of Patent Document 1 includes a power source for driving an upper
yarn guide pipe for catching yarn unwound from the reverse rotating package, and includes
a controller for moving a mouth portion of the upper yarn guide pipe at a speed not
more than the speed of yarn unwound from a yarn layer by the reverse rotation of the
package. Patent Document 1 describes that after the upper yarn is caught, the movement
speed of the mouth portion and the yarn unwinding speed of the reverse rotating package
should be desirably controlled to become equal to each other.
CITATION LIST
Patent Literature
[0004] Patent Literature 1: Patent Application Laid Open Gazette No.
2009-155101
SUMMARY OF THE INVENTION
Problem to Be Solved by the Invention
[0005] Regarding the winding unit disclosed by Patent Literature 1, the upper yarn guide
pipe continuously holds the upper yarn caught at its mouth portion after the upper
yarn guide pipe catching the upper yarn finishes its movement for guiding the upper
yarn to the yarn joining device. Therefore, when the mouth comes to rest, the package
desirably stops its reverse rotation simultaneously. However, the rotation inertia
varies in correspondence to weight, so that the period of time from the start of controlling
to stop the reverse rotation of the package until the actual stop of the package varies
in correspondence to variation in the quantity of yarn wound to the package (variation
in the wound yarn layer diameter). Therefore, the yarn unwound from the package may
have an irregular length so that the upper yarn guided by the upper yarn guide pipe
may be torn off or loosened, whereby the yarn joining operation may be wrongly performed.
[0006] The present invention is created in view of the above-mentioned situation. A main
object of the invention is to provide a yarn winding unit which can control a timing
of actually stopping the reverse rotation of the package.
Solution to the Problem and Effect
[0007] The foregoing description is given of the problem to be solved by the invention.
Solution to the problem and effects of the solution will now be described.
[0008] In a first aspect of the invention, provided is a yarn winding unit configured as
follows: A yarn winding unit comprises a winding section, a driving section, a yarn
catching section and a unit controller. The winding section winds a yarn to form a
package. The driving section rotates the package reversibly in the rotation direction.
The yarn catching section catches a yarn from the package rotated by the driving section
in a reverse direction opposite to a yarn winding direction. The unit controller controls
a rotation direction of the package and starting/stopping of rotation of the package.
The unit controller changes a timing of issuing at least either a reverse rotation
stop command or a reverse rotation speed reduction command issued to the driving section
in correspondence to rotational inertia of the package. The reverse rotation stop
command is defined as a command issued to the driving section to stop a reverse rotation
of the package which is the rotation of the package in the reverse direction, and
the reverse rotation speed reduction command is defined as a command issued to the
driving section to reduce the reverse rotation speed of the package for the purpose
of stopping the reverse rotation of the package.
[0009] Therefore, the timing of actually stopping the reverse rotation of the package can
be controlled in correspondence to the rotational inertia.
[0010] Preferably, in the yarn winding unit, when the rotational inertia of the package
is large, the unit controller issues at least either the reverse rotation stop command
or the reverse rotation speed reduction command issued to the driving section at a
timing earlier than that when the rotational inertia of the package is small.
[0011] Therefore, the commands for speed-reducing and stopping the reverse rotation are
issued to the driving section at the respective timings corresponding to variation
of the rotational inertia so that the fluctuation of the timing of actually stopping
the reverse rotation of the package is reduced appropriately.
[0012] Preferably, in the yarn winding unit, the unit controller issues at least either
the reverse rotation stop command or the reverse rotation speed reduction command
issued to the driving section so that the reverse rotation of the package is actually
stopped at a constant timing regardless of variation in quantity of yarn wound into
the package.
[0013] Therefore, the motion timing after the stopping of the reverse rotation of the package
can be regulated, thereby simplifying the control.
[0014] Preferably, the yarn winding unit is configured as follows: The yarn winding unit
comprises a yarn joining device for joining a yarn caught by the yarn catching section
to another yarn. The unit controller matches the timing at which the reverse rotation
of the package is actually stopped with a timing at which the yarn catching section
holding the yarn from the package arrives at a guide position for guiding the yarn
to the yarn joining device and comes to rest there.
[0015] Therefore, the timing at which the reverse rotation of the package can be matched
with the timing at which the yarn catching section finishes guiding the yarn to the
yarn joining device and comes to rest. Accordingly, the yarn is prevented from being
torn off or loosened immediately before the yarn joining device is activated, whereby
the yarn joining device stably performs the yarn joining operation.
[0016] Preferably, the yarn winding unit is configured as follows: The yarn winding unit
comprises a yarn layer diameter obtaining section which obtains a yarn layer diameter
of yarn wound in the package. When the yarn layer diameter obtained by the yarn layer
diameter obtaining section is large, the unit controller changes the timing of issuing
at least either the reverse rotation stop command or the reverse rotation speed reduction
command so that the timing becomes different from that when the obtained diameter
is small.
[0017] Therefore, the timing at which the reverse rotation of the package is actually stopped
is appropriately controlled by using the influence of variation in the yarn layer
diameter of the package to variation in the rotational inertia.
[0018] Preferably, the yarn winding unit is configured as follows: The yarn winding unit
comprises a cradle which supports the package rotatably and rotates according to increase
of the yarn layer diameter of the yarn wound in the package. The yarn layer diameter
obtaining section is an angle sensor which detects a rotation angle of the cradle.
[0019] Therefore, such a simple configuration is enough to obtain the required yarn layer
diameter of the package.
[0020] Alternatively, the yarn winding unit may be configured as follows: The yarn winding
unit comprises a yarn feeding section and a yarn running speed detection device. The
yarn feeding section unwinds a yarn from a yarn supplying bobbin and feeds the winding
section with the yarn. The yarn running speed detection device is provided on a yarn
running path between the yarn feeding section and the winding section to detect a
running speed of yarn. The yarn layer diameter obtaining section obtains the yarn
layer diameter by calculation using the running speed of yarn detected by the yarn
running speed detection device.
[0021] Therefore, such a simple configuration is enough to obtain the required yarn layer
diameter of the package.
[0022] In a second aspect of the invention, a yarn winding apparatus comprising the yarn
winding unit is configured as follows: The yarn winding apparatus comprises a setting
section which can set the timing of issuing at least either the reverse rotation stop
command or the reverse rotation speed reduction command issued to the driving section
in correspondence to rotational inertia of the package.
[0023] Therefore, for example, if a kind of yarn to be formed into the package is changed,
the set content can be changed to appropriately control the timing at which the reverse
rotation of the package is actually stopped.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024]
[FIG. 1]A schematic front view of an automatic winder according to an embodiment of
the present invention illustrating an entire configuration thereof.
[FIG. 2] A front view and a block diagram of a winder unit illustrating a general
configuration thereof.
[FIG. 3] A side view of the winder unit illustrating a state that a yarn is divided
into two divisional yarns and yarn ends of the respective divisional yarns are guided
to a yarn joining device.
[FIG. 4]An enlarged right side view of the winder unit illustrating a cradle and its
surroundings.
[FIG. 5] A timing chart illustrating an exemplary reverse rotation control of a package
in the winder unit.
[FIG. 6] A diagram illustrating contents set in a base control device regarding a
timing of issuing a reverse rotation speed reduction command to a package driving
motor and a timing of issuing a reverse rotation stop command to the package driving
motor.
[FIG. 7] A timing chart illustrating a reverse rotation control of the package according
to a first modified embodiment.
[FIG. 8] A timing chart illustrating a reverse rotation control of the package according
to a second modified embodiment.
DETAILED DESCRIPTION OF EMBODIMENTS
[0025] An embodiment of the present invention will now be described with reference to drawings.
FIG. 1 is a schematic front view of an automatic winder 100 according to an embodiment
of the present invention illustrating an entire configuration thereof.
[0026] The automatic winder (yarn winding apparatus) 100 mainly includes aligned winder
units (yarn winding units) 10, a blower box 70, a base controlling device (a setting
section) 80 and a doffer 90.
[0027] An unillustrated blower is disposed in the blower box 70. The blower functions as
a compressed air source for supplying compressed air to the respective winder units
10. The blower also functions as a negative pressure source for applying negative
pressure to the respective winder units 10.
[0028] The base controlling device 80 includes an operation section 81 and a display section
82. The operation section 81 and the display section 82 are communicative with the
respective winder units 10. An operator who operates the automatic winder 100 can
operate the operation section 81 so as to input a prescribed set value or so as to
select an optional controlling manner. Therefore, the plurality of winder units 10
can be collectively managed. The base control device 80 controls motion of the doffer
90. The display section 82 can display the quantity of yarn 12 wound by each winder
unit 10, a content of trouble which occurs, and so on.
[0029] The doffer 90 is configured so that when one winder unit 10 comes to have a package
20 fully wound (the predetermined quantity of yarn 12 is wound), the doffer 90 runs
to the position of the corresponding winder unit 10, removes the fully wound package
20, and sets an empty winding bobbin 22.
[0030] A configuration of the winder unit 10 will now be described with reference to FIGS.
2 to 4. FIG. 2 is a front view and a block diagram of a winder unit 10 illustrating
a general configuration thereof. FIG. 3 is a side view of the winder unit 10 illustrating
a state that a yarn 12 is divided into two divisional yarns and yarn ends of the divisional
yarns are guided to a yarn joining device 3. FIG. 4 is an enlarged right side view
of the winder unit 10 illustrating a cradle 21 and its surroundings.
[0031] As shown in FIG. 2, each winder unit 10 includes a main winder unit body 40 and a
unit controller 50. The main winder unit body 40 includes a yarn feeding section 1
and a winding section 2. The winder unit 10 unwinds the yarn 12 from a yarn supplying
bobbin 11 supplied in the yarn feeding section 1, traverses the unwound yarn 12 and
winds it around the winding bobbin 22 so as to form the package 20. In the following
description, with regard to the package 20, rotation in a direction to wind the yarn
12 may be referred to as "normal rotation", and rotation in another opposite direction
may be referred to as "reverse rotation". Words "upstream" and "downstream" mean upstream
and downstream in a running direction of the yarn 12 when it is wound.
[0032] The unit controller 50 includes a CPU and a ROM, for example. The ROM stores programs,
control tables and so on for controlling respective configurations of the main winding
unit body 40. The CPU executes the programs stored in the ROM.
[0033] The yarn feeding section 1 can support the yarn supplying bobbin 11 mounted on an
unillustrated conveyance tray at a predetermined position therein, and can unwind
the yarn 12 from the yarn supplying bobbin 11. The yarn feeding section 1 is configured
so as to eject the yarn supplying bobbin 11 which becomes empty after complete unwinding
of the yarn 12 therefrom, and so as to receive another new yarn supplying bobbin 11
supplied from an unillustrated yarn supplying bobbin supplying device. Incidentally,
the yarn feeding section 1 is not limited to the above-mentioned one with the conveyance
tray. For example, the yarn feeding section 1 may be a magazine type yarn feeding
section configured so as to support the yarn supplying bobbin supplied from an unillustrated
magazine, and so as to unwind the yarn 12 to feed the yarn 12.
[0034] The winding section 2 has a principal configuration including the cradle 21, a contact
roller 26 and a traverse device 25. The cradle 21 is configured so that the winding
bobbin 22 can be attached to the cradle 21.
[0035] The cradle 21 holds the winding bobbin 22 (the package 20) detachably attached thereto.
Although a yarn layer diameter of the package 20 increases according to the winding
of the yarn 12 onto the winding bobbin 22, the cradle 21 is swingable forward and
rearward of the winder unit 10 so that the increase of yarn layer diameter of the
package 20 can be absorbed by swinging the cradle 21.
[0036] In other words, even if the yarn layer diameter of the package 20 varies according
to the winding of the yarn 12, a surface of the package 20 can appropriately contact
the contact roller 26.
[0037] A package driving motor 61 is mounted on the cradle 21. For example, a servomotor
serves as the package driving motor 61. The winding section 2 rotates the winding
bobbin 22 by driving the package driving motor 61 so as to wind the yarn 12 onto a
surface of the winding bobbin 22 (or the surface of the package 20).
[0038] A rotation shaft of the package driving motor 61 is joined to the winding bobbin
22 unrotatably relative to the winding bobbin 22 (in a direct drive manner) when the
winding bobbin 22 is supported by the cradle 21. The package driving motor 61 is electrically
connected to the unit controller 50 so that the unit controller 50 can control the
rotation speed and direction of the package driving motor 61.
[0039] The contact roller 26 is rotatably supported and is configured so as to be upwardly
contactable with the surface of the winding bobbin 22 or the surface of the package
20. The contact roller 26 can support at least a part of weight of the winding bobbin
22 or the package 20.
[0040] The traverse device 25 includes a traverse arm 35 and a traverse driving motor 36.
The traverse arm 35 is swingably supported and is configured so as to be able to hold
the yarn 12 at a tip thereof. The traverse driving motor 36 drives the traverse arm
35. The traverse driving motor 36 is electrically connected to the unit controller
50 so that the unit controller 50 can traverse the yarn 12 wound to the package 20
at a predetermined lead angle by driving the traverse driving motor 36 in cooperation
with the package driving motor 61.
[0041] The cradle 21 includes a lift-up mechanism 60 as shown in FIG. 4. The lift-up mechanism
60 can separate the package 20 from the contact roller 26 by swinging the cradle 21
at need.
[0042] Referring to FIG. 4, the lift-up mechanism 60 includes a rotation plate 17, a spring
18 and an air cylinder 71.
[0043] The rotation plate 17 is rotatably centered on a rotation shaft 16 and is rotatably
integral with the cradle 21. The rotation shaft 16 is provided with an angle sensor
63 (a yarn layer diameter obtaining section 63) for detecting a rotation angle of
the cradle 21. For example, a potentiometer may serve as the angle sensor 63.
[0044] The spring 18 is configured as a tension spring connected to the rotation plate 17.
The spring 18 is configured so as to pull the rotation plate 17 in a direction to
raise the cradle 21. Therefore, while the package 20 is expanded by winding the yarn
12 onto the winding bobbin 22, a part of the weight of the package 20 is canceled
by the spring force so as to prevent the contact pressure between the contact roller
26 and the package 20 from becoming excessive.
[0045] The air cylinder 71 is telescopically activated by compressed air supplied from an
electromagnetic valve 64 and is connected to the rotation plate 17. When the package
20 has a bit of yarn 12 wound therein, the air cylinder 71 lowers the cradle 21 against
the spring 18 so as to press the contact roller 26 against the package 20 with an
appropriate contact pressure. When the package 20 becomes large by getting the yarn
12 wound therein, the air cylinder 71 operates so that the spring 18 raises the cradle
21 to reduce the increase of the contact pressure according to increase of the weight
of the package 20.
[0046] Further, when the yarn 12 loses its continuity (hereinafter, this state may be referred
to as "divided into two divisional yarns") between the yarn feeding section 1 and
the winding section 2, the air cylinder 71 applies a force together with the spring
18 in the direction to raise the cradle 21 so as to raise the package 20 away from
the contact roller 26 as illustrated in chained lines in FIG. 4. Therefore, the above-mentioned
lift-up function is realized.
[0047] The winder unit 10 has a yarn running path between the yarn feeding section 1 and
the winding section 2, and includes an unwinding assist device 13, a tension applying
device 14, a lower yarn catching pipe 4, the yarn joining device 3, a yarn quality
measurement device (yarn monitoring device) 19 and an upper yarn catching pipe (yarn
catching section) 5, which are arranged on the yarn running path.
[0048] The unwinding assist device 13 includes a regulation member 13a coverable over a
core tube of the yarn supplying bobbin 11. The regulation member 13a is substantially
cylindrical and is disposed to abut against a balloon formed at an upper portion of
the yarn layer on the yarn supplying bobbin 11. In this regard, the yarn 12 unwound
from the yarn supplying bobbin 11 has a portion swung by a centrifugal force, and
this portion is referred to as the "balloon".
[0049] By bringing the regulation member 13a into contact with the balloon, a tension is
applied to the balloon portion of the yarn 12 so as to prevent the yarn 12 from being
excessively swung. Therefore, the yarn 12 can be appropriately unwound from the yarn
supplying bobbin 11.
[0050] The tension applying device 14 applies a predetermined tension to the running yarn
12. In the present embodiment, the tension applying device 14 is configured as a gate
type device including fixed comb teeth and movable comb teeth. The movable comb teeth
are biased so as to mesh with the fixed comb teeth.
[0051] The mutually meshing movable and fixed comb teeth have spaces therebetween, and the
yarn 12 is zigzagged and passed through the spaces so as to receive an appropriate
tension, thereby enhancing the quality of the package 20. The tension applying device
14 is not limited to the above-mentioned gate type device. For example, a disk type
device may serve as the tension applying device 14.
[0052] The lower yarn catching pipe 4 is configured so that when the yarn 12 is divided
into two divisional yarns between the yarn feeding section 1 and the winding section
2 for some reason, the lower yarn catching pipe 4 catches the yarn 12 (a yarn end)
on the yarn supplying bobbin 11 side and guides it to the yarn joining device 3.
[0053] More specifically, the lower yarn catching pipe 4 is rotatable centered on a pipe
shaft 41 and is formed at a tip thereof with a suction mouth 42. An appropriate negative
pressure source is connected to the lower yarn catching pipe 4 so as to generate a
suction flow at the suction mouth 42.
[0054] Due to this configuration, when the yarn is divided into two divisional yarns, the
suction mouth 42 of the lower yarn catching pipe 4 catches the lower yarn at a position
illustrated in chained lines in FIG. 3, and then, the lower yarn catching pipe 4 is
rotated upward centered on the pipe shaft 41 so as to guide the lower yarn to the
yarn joining device 3.
[0055] When the yarn 12 is divided into two divisional yarns, the yarn 12 (the yarn end)
on the yarn feeding section 1 side and the yarn 12 (a yarn end) on the winding section
2 side are joined to each other by the yarn joining device 3. In the present embodiment,
the yarn joining device 3 is configured as a splicer which twists the yarn ends together
by swirling airflow generated from the compressed air. However, the yarn joining device
3 is not limited to the splicer. For example, a mechanical knotter may serve as the
yarn joining device 3.
[0056] The yarn quality measurement device 19 monitors a thickness or so on of the running
yarn 12 by an appropriate sensor so as to detect a yarn defect. A cutter 24 is provided
close to the yarn quality measurement device 19 so as to cut the yarn 12 immediately
after the yarn quality measurement device 19 detects a yarn defect.
[0057] The upper yarn catching pipe 5 is configured so that when the yarn 12 is divided
into two divisional yarns, the upper yarn catching pipe 5 catches the yarn 12 (the
yarn end) on the winding section 2 side and guides it to the yarn joining device 3.
[0058] More specifically, the upper yarn catching pipe 5 is rotatable centered on a shaft
51, and is formed at a tip thereof with a suction mouth 52. The above-mentioned blower
is connected to the upper yarn catching pipe 5 so as to be able to generate a suction
flow in the suction mouth 52.
[0059] The suction mouth 52 is formed in a long narrow shape such as to include the roll
width of the package 20. Therefore, the suction flow is applied to the outer peripheral
surface of the package 20 thoroughly in the roll width direction.
[0060] An unillustrated shutter member is disposed between the upper yarn catching pipe
5 and the blower. By selectively opening or closing the shutter member, the suction
flow into the suction mouth 52 is selectively generated or stopped.
[0061] An output shaft of a motor 62 is connected to the upper yarn catching pipe 5. The
motor 62 is electrically connected to the unit controller 50 so that the unit controller
50 can control rotation/stop of the motor 62.
[0062] Due to the configuration, when the yarn feeding is terminated or when the yarn is
divided into two divisional yarns, the suction mouth 52 of the upper yarn catching
pipe 5 catches the upper yarn at an upper yarn catching position as drawn in chained
lines in FIG. 3 and then rotates centered on the shaft 51 to a yarn joining position
as drawn in solid lines in FIG. 3 so as to guide the upper yarn to the yarn joining
device 3.
[0063] In this way, the winder unit 10 can form the package 20 by winding the yarn 12 onto
the winding bobbin 22.
[0064] When the yarn 12 is divided into two divisional yarns between the yarn feeding section
1 and the winding section 2, a series of operations of the winder unit 10 are performed
since the divisional yarns 12 are joined together until the joined yarn is wound again.
The series of operations of the winder unit 10 will be described in detail with reference
to FIGS. 2, 3 and 5. FIG. 5 is a timing chart illustrating an exemplary reverse rotation
control of the package 20 in the winder unit 10.
[0065] In the winder unit 10, when the yarn 12 is divided into two divisional yarns, the
yarn end of the divisional yarn 12 on the package 20 (the winding section 2) side
is wound into the package 20 which is inertially rotating. Reasons why the yarn 12
is divided into two divisional yarns include that the yarn 12 is cut by the cutter
24 automatically because the yarn quality measurement device 19 detects a yarn defect,
and that the yarn 12 is broken by an accidentally generated large tension. These reasons
should not be considered to be restrictive. In the following description, the yarn
end on the package 20 side may be referred to as the "upper yarn end".
[0066] The unit controller 50 transmits a drive signal to the motor 62 to rotate the upper
yarn catching pipe 5 upward to an upper yarn catching position as drawn in chained
lines in FIG. 3 so as to make the suction mouth 52 approach the package 20. As a result,
the suction mouth 52 of the upper yarn catching pipe 5 comes to the position where
it substantially confronts the surface of the package 20.
[0067] When the suction mouth 52 reaches the upper yarn catching position, the unit controller
50 transmits a drive signal to the package driving motor 61 to rotate the package
20 in a yarn unwinding direction (reversely) opposite to the yarn winding direction,
and to generate the suction airflow in the suction mouth 52. Therefore, the upper
yarn end unwound from the package 20 by the reverse rotation of the package 20 is
sucked into the upper yarn catching pipe 5 by the suction airflow when it runs through
the position confronting the suction mouth 52.
[0068] On the other hand, the yarn end of the divisional yarn 12 on the yarn supplying bobbin
11 (the yarn feeding section 1) side is caught by a suction airflow generated at a
tip of the lower yarn catching pipe 4. In this regard, in the following description,
the yarn end on the yarn supplying bobbin 11 side may be referred to as the "lower
yarn end".
[0069] After the upper yarn end and the lower yarn end are caught, the unit controller 50
transmits a drive signal to the motor 62 to rotate the upper yarn catching pipe 5
downward as directed by a bold arrow in FIG. 3. Also, the unit controller 50 rotates
the lower yarn catching pipe 4 upward as directed by another bold arrow. Accordingly,
the yarn end on the package 20 side caught by the upper yarn catching pipe 5 and the
yarn end on the yarn supplying bobbin 11 side caught by the lower yarn catching pipe
4 are guided to the yarn joining device 3.
[0070] Subsequently, the yarn ends of divisional yarns are joined to each other by the yarn
joining device 3. When the yarn 12 becomes continuous between the yarn feeding section
1 and the winding section 2, the unit controller 50 controls the package driving motor
61 so as to forwardly rotate the package 20 to restart the winding of the yarn 12.
[0071] The above-mentioned control processes will now be described in detail with reference
to the timing chart of FIG. 5.
[0072] Immediately after the yarn 12 being wound is divided into two divisional yarns, the
unit controller 50 controls the package driving motor 61 so as to stop the rotation
of the package 20. Almost simultaneously, the lift-up mechanism 60 moves to raise
the cradle 21 so as to separate the package 20 from the contact roller 26.
[0073] Afterward, at a timing t0 as shown in FIG. 5, the unit controller 50 starts the upward
rotation of the upper yarn catching pipe 5. As a result, at a timing t1, the suction
mouth 52 reaches at the upper yarn catching position as drawn in chained lines in
FIG. 3. The shutter member disposed on a connection path between the upper catching
pipe 5 and the blower is opened at a time when the upper yarn catching pipe 5 starts
its upward rotation. At the upper yarn catching position, the suction mouth 52 is
adjacent to the surface of the package 20 so as to apply a strong suction flow to
the surface of the package 20.
[0074] At the timing t1, the unit controller 50 transmits a signal to the package driving
motor 61 so as to start reverse rotation of the package 20. At a timing when a predetermined
time passes after the start of reverse rotation of the package 20, the lift-up mechanism
60 cancels the raising of the package 20. Afterward, the first speed V1 defined as
the reverse rotation speed of the package 20 is kept constant.
[0075] According to the reverse rotation, the upper yarn end is unwound from the package
20 and is caught in the suction mouth 52. A yarn detection sensor 53 is disposed inside
of the upper yarn catching pipe 5. When a considerable quantity of the upper yarn
end is sucked into suction mouth 52, the yarn detection sensor 53 detects the upper
yarn end. For example, an optical sensor may serve as the yarn detection sensor.
[0076] The reverse rotation of the package 20 at the first speed V1 is performed to a predetermined
time since the start of reverse rotation and is further maintained until the elapse
of a predetermined time. Then, at a timing t2, the unit controller 50 controls the
lift-up mechanism 60 to raise the package 20 again and to increase the reverse rotation
speed of the package 20 from the first speed V1 to a predetermined second speed V2
higher than the first speed V1. Further, the suction mouth 52 slightly moves away
from the surface of the package 20. The raising of the package 20 by the lift-up mechanism
60 is canceled approximately at the timing at which the reverse rotation of the package
20 reaches the second speed V2.
[0077] According to the reverse rotation of the package 20, the upper yarn end is further
unwound from the package 20 and is sucked into the suction mouth 52. In the state
where the suction mouth 52 is moved a little away from the package 20, the reverse
rotation of the package 20 at the second speed V2 is maintained for a time corresponding
to the length of the detected yarn defect plus an appropriate margin time. Therefore,
a portion including the whole yarn defect can be removed from the yarn wound in the
package 20. At this time, the reverse rotation speed of the package 20 is the relatively
high second speed V2 so that the yarn 12 can be promptly unwound.
[0078] Afterward, at a timing t3, the unit controller 50 transmits the drive signal to the
upper yarn catching pipe 5 so as to rotate the upper yarn catching pipe 5 to move
the suction mouth 52 downward (to the yarn joining position for guiding the upper
yarn to the yarn joining device 3). At a timing t4 before the upper yarn catching
pipe 5 reaches the yarn joining position, the unit controller 50 transmits the drive
signal to the package driving motor 61 so as to start the reverse rotation speed reduction
of the package 20.
[0079] In the present embodiment, since the timing t4 defined as the timing for starting
the speed reduction, the unit controller 50 linearly reduces a command speed issued
to the package driving motor 61 from the second speed (as a reverse rotation speed
reduction command), and finally zeroes the command speed at a timing t5 (as a reverse
rotation stop command). However, if the yarn layer diameter of the package 20 is large,
the reduction and zeroing of the command speed may insufficiently weaken the strong
inertial rotation of the package 20, so that the reverse rotation of the package 20
may be actually stopped with a delay after the timing t5.
[0080] In this regard, according to the present embodiment, the unit controller 50 changes
the timing of issuing the reverse rotation stop command and the timing of issuing
the reverse rotation speed reduction command issued to the package driving motor 61
in correspondence to the yarn layer diameter of the package 20. The reverse rotation
stop command is defined as a command issued to the package driving motor 61 to stop
the reverse rotation of the package 20, and the reverse rotation speed reduction command
is defined as a command issued to the package driving motor 61 to reduce the reverse
rotation speed of the package 20 for the purpose of stopping the reverse rotation
of the package 20. More specifically, when the yarn layer diameter of the package
20 is large, the unit controller 50 issues the reverse rotation stop command and the
reverse rotation speed reduction command at respective timings earlier than those
when the yarn layer diameter of the package 20 is small. Referring to the example
of FIG. 5, if the yarn layer diameter of the package 20 is small, the reverse rotation
speed reduction command is issued at the timing t4, and the reverse rotation stop
command is issued at the timing t5. On the contrary, if the yarn layer diameter of
the package 20 is large, the reverse rotation speed reduction command is issued at
a timing t4x, and the reverse rotation stop command is issued at a timing t5x. Due
to the change of the respective timings of issuing the reverse rotation speed reduction
command and the reverse rotation stop command, the reverse rotation of the package
20 can be actually stopped at an expected timing (i.e., the timing t5 at which the
upper yarn catching pipe 5 arrives at the yarn joining position and comes to rest
there). As a result, the upper yarn is prevented from being torn off or loosened
[0081] In this way, the divisional yarn 12 from the package 20 is guided to the yarn joining
device 3 and the yarn joining operation by the yarn joining device 3 is started. Substantially
simultaneously, the shutter member disposed on the connection path between the upper
yarn catching pipe 5 and the blower is closed so as to stop the suction flow in the
suction mouth 52.
[0082] An operator can set a relation between the yarn layer diameter and the timing at
which the unit controller 50 issues the reverse rotation stop command or the reverse
rotation speed reduction command. For example, referring to FIG. 6, the yarn layer
diameter may be classified by size into three stages so that the timing of issuing
the reverse rotation speed reduction command to the package driving motor 61 and the
timing of issuing the reverse rotation stop command to the package driving motor 61
may be set in correspondence to each of the three stages.
[0083] The operation section 81 of the base controlling device 80 can be operated by an
operator so as to adjust the set contents in the base controlling device 80. Therefore,
the automatic winder 100 can flexibly adapt to variation in weight density of the
package 20 caused by variation in kind of the yarn 12, variation in lead angle for
winding the yarn 12, or so on.
[0084] As mentioned above, the winder unit 10 according to the present embodiment comprises
the winding section 2, the package winding motor 61, the upper yarn catching pipe
5 and the unit controller 50. The winding section 2 winds the yarn 12 to form the
package 20. The package driving motor 61 rotates the package 20 reversibly in the
rotation direction. The upper yarn catching pipe 5 catches the yarn 12 from the package
20 rotated by the package driving motor 61 in the reverse direction opposite to the
yarn winding direction. The unit controller 50 controls the rotation direction of
the package 20 and starting/stopping of rotation of the package 20. The unit controller
50 changes the timing of issuing at least either the reverse rotation stop command
or the reverse rotation speed reduction command issued to the package driving motor
61 in correspondence to rotational inertia of the package 20. The reverse rotation
stop command is defined as a command issued to the package driving motor 61 to stop
the reverse rotation of the package 20, and the reverse rotation speed reduction command
is defined as a command issued to the package driving motor 61 to reduce the reverse
rotation speed of the package 20 for the purpose of stopping the reverse rotation
of the package 20.
[0085] Therefore, the timing of actually stopping the reverse rotation of the package 20
can be controlled in correspondence to the rotational inertia.
[0086] In the winder unit 10 according to the present embodiment, when the rotational inertia
of the package 20 is large, the unit controller 50 issues at least either the reverse
rotation stop command or the reverse rotation speed reduction command at a timing
earlier than that when the rotational inertia of the package 20 is small.
[0087] Therefore, the commands for speed-reducing and stopping the reverse rotation are
issued to the package driving motor 61 at the respective timings corresponding to
variation of the rotational inertia so that the fluctuation of the timing of actually
stopping the reverse rotation of the package 20 is reduced appropriately.
[0088] In the winder unit 10 according to the present embodiment, the unit controller 50
issues at least either the reverse rotation stop command or the reverse rotation speed
reduction command so that the reverse rotation of the package 20 is actually stopped
at the constant timing (the timing t5) regardless of variation in quantity of the
yarn 12 wound into the package 20.
[0089] Therefore, the motion timing (for example, the timing of yarn joining operation by
the yarn joining device 3) after the stopping of the reverse rotation of the package
20 can be regulated, thereby simplifying the control.
[0090] According to the present embodiment, the winder unit 10 comprises the yarn joining
device 3 for joining the divisional yarn 12 caught by the upper yarn catching pipe
5 to the other divisional yarn 12. The unit controller 50 matches the timing at which
the reverse rotation of the package 20 is actually stopped with the timing (the timing
t5) at which the upper yarn catching pipe 5 holding the divisional yarn 12 from the
package 20 arrives and stops at the guide position for guiding the divisional yarn
12 to the yarn joining device 3.
[0091] Therefore, the timing at which the reverse rotation of the package 20 can be matched
with the timing at which the upper yarn catching pipe 5 finishes guiding the divisional
yarn 12 to the yarn joining device 3 and comes to rest. Accordingly, the divisional
yarn 12 is prevented from being torn off or loosened immediately after the reverse
rotation of the package 20 is actually stopped, whereby the yarn joining device 3
stably performs the yarn joining operation.
[0092] According to the present embodiment, the winder unit 10 comprises the angle sensor
63 which obtains the diameter of the yarn layer wound in the package 20. When the
diameter of the yarn layer obtained by the angle sensor 63 is large, the unit controller
50 changes the timing of at least either the reverse rotation stop command or the
reverse rotation speed reduction command in comparison with that when the obtained
diameter is small.
[0093] Therefore, the timing at which the reverse rotation of the package 20 is actually
stopped is appropriately controlled by using the influence of variation in the yarn
layer diameter of the package 20 to variation in the rotational inertia.
[0094] According to the present embodiment, the winder unit 10 comprises the cradle 21 which
supports the package 20 rotatably and rotates according to increase of the diameter
of the yarn layer of the yarn 12 wound in the package 20. The angle sensor 63 obtains
the yarn layer diameter by detecting the rotation angle of the cradle 21.
[0095] Therefore, such a simple configuration is enough to obtain the required diameter
of the yarn layer in the package 20.
[0096] Alternatively, the winder unit 10 may obtain the yarn layer diameter of the package
20 in the following way: The winder unit 10 comprises an unillustrated yarn running
speed detection device provided on the yarn running path between the yarn feeding
section 1 and the winding section 2. The wound length of the yarn 12 is calculated
by time-integrating the running speed of yarn detected by the yarn running speed detection
device. The wound length is converted by a common formula into a yarn layer diameter.
In this way, the yarn layer diameter of the package 20 can be obtained by calculation.
[0097] For example, the yarn running speed detection device includes two sensors (e.g.,
optical sensors) aligned along the yarn running path. The two sensors detect unevenness
of yarn respectively, and time changes of respective waveforms detected by the respective
sensors are compared to calculate a time difference between a time at which a portion
of the yarn passes one sensor and another time at which the portion of the yarn passes
the other sensor. Therefore, the yarn running speed can be calculated based on the
calculated time difference. Alternatively, the yarn quality measurement device 19
may have a function to detect the yarn running speed based on the above-mentioned
principle.
[0098] Therefore, such a simple configuration is enough to obtain the required yarn layer
diameter of the package 20.
[0099] According to the present embodiment, the automatic winder 100 comprises the winder
unit 10, and comprises the base controlling device 80. The base controlling device
80 can set the timing of issuing at least either the reverse rotation stop command
or the reverse rotation speed reduction command issued to the package driving motor
61 in correspondence to rotational inertia of the package 20. The reverse rotation
stop command is defined as a command issued to the package driving motor 61 to stop
the reverse rotation of the package 20, and the reverse rotation speed reduction command
is defined as a command issued to the package driving motor 61 to reduce the reverse
rotation speed of the package 20 for the purpose of stopping the reverse rotation
of the package 20. The set contents in the base controlling device 80 can be adjusted
by an operator's operation.
[0100] Therefore, for example, if a kind of yarn 12 to be formed into the package 20 is
changed, the set content can be changed to appropriately control the reverse rotation
of the package 20.
[0101] Two modified embodiments regarding the speed reduction and stop of the reverse rotation
of the package will now be described. In the description of the two modified embodiments,
members identical or similar to those in the above-mentioned embodiment may be designated
by the same reference numerals and description of them may be omitted.
[0102] In a first modified embodiment as shown in FIG. 7, when the yarn layer diameter of
the package 20 is large, the unit controller 50 issues the reverse rotation speed
reduction command to the package driving motor 61 at a timing earlier than the timing
when the yarn layer diameter is small. More specifically, when the yarn layer diameter
of the package 20 is small, the reverse rotation speed reduction command is issued
at the timing t4. When the yarn layer diameter of the package 20 is large, the reverse
rotation reverse rotation speed reduction command is issued at the timing t4x.
[0103] However, in this modified embodiment, when the yarn layer diameter of the package
20 is large, the slope of reducing the command speed for reducing the reverse rotation
speed of the package 20 is gentler than that when the yarn layer diameter is small.
As a result, the reverse rotation stop command (i.e., the command for zeroing the
reverse rotation speed) to the package driving motor 61 is issued at a timing t5 constantly
regardless of variation in the yarn layer diameter of the package 20.
[0104] In a second modified embodiment as shown in FIG. 8, the unit controller 50 issues
the reverse rotation speed reduction command at the timing t4 constantly regardless
of variation in the yarn layer diameter of the package 20.
[0105] However, in this modified embodiment, when the yarn layer diameter of the package
20 is large, the slope of reducing the command speed for reducing the reverse rotation
speed of the package 20 is steeper than that when the yarn layer diameter of the package
20 is small. As a result, when the yarn layer diameter of the package 20 is large,
the unit controller 50 issues the reverse rotation stop command (i.e., the command
for zeroing the reverse rotation speed) at a timing t5x which is earlier than that
(the timing t5) when the yarn layer diameter of the package 20 is small.
[0106] As understood from the above-mentioned two modified embodiments, the slope of reducing
the command speed issued to the package driving motor 61 to reduce the reverse rotation
speed of the package 20 may be changed in correspondence to variation in the yarn
layer diameter of the package 20.
[0107] The foregoing description is given of a preferred embodiment of the present invention
and modified embodiments. However, for example, the above-mentioned configurations
may be modified as follows.
[0108] The control of the reverse rotation of the package 20 before the timing t3 shown
in FIG. 5 may be altered from the above-mentioned control into another appropriate
control.
[0109] The decline of the command speed outputted from the unit controller 50 to the package
driving motor 61 to reduce the reverse rotation speed of the package 20 may be rated
as illustrated in a smooth curve instead of the linear change as shown in FIG. 5 and
so on.
[0110] The timings of issuing the reverse rotation speed reduction or stop command to the
package driving motor may be set based on classification of the yarn layer diameter
into two, four or more stages instead of the three stages as shown in FIG. 6. Further,
function parameters may be set in a base controlling device 80 so as to enable stepless
changing of these timings.
[0111] Instead of the control based on the yarn layer, a control operation may be performed
based on another parameter expressing a magnitude of the rotational inertia (e.g.,
a package weight).
[0112] During the reverse rotation of the package 20, the unit controller 50 may issue the
reverse rotation stop command (command for zeroing the speed) to the package driving
motor 61 without the previous issue of the speed reduction command.
[0113] A brake mechanism may be provided on a portion of the package driving motor 61 so
that the brake mechanism is operated for braking during the operation for the reverse
rotation stopping or speed reduction.
[0114] The configuration of controlling reverse rotation of the package 20 according to
the present invention is not limited to the winder unit 10 in which the package 20
is rotated directly by the package driving motor 61 and the yarn 12 is traversed by
the arm-type traverse device 25. For example, a columnar drum contacting the outer
peripheral surface of the package 20 may be driven by a motor so that the yarn can
be traversed along a spiral traversing groove formed on the drum. In this case, the
motor for driving the drum serves as the driving section.
DESCRIPTION OF THE REFERENCE NUMERALS
[0115]
- 2
- a winding section
- 5
- an upper yarn catching pipe (a yarn catching section)
- 10
- a winder unit (a yarn winding unit)
- 12
- a yarn
- 20
- a package
- 50
- a unit controller
- 61
- a package driving motor (a driving section)