YARN WINDING DEVICE AND YARN WINDING METHOD
BACKGROUND OF THE INVENTION
1. Field of the Invention
5 The present invention relates to a yarn winding device and a
yarn winding method adapted to wind a yarn unwound from a yarn
supplying bobbin.
2. Description of the Related Art
10 Conventionally, there is known an automatic winder that unwinds
a yarn of a yarn supplying bobbin produced by a fine spinning machine
and the like, and joins yarns of a plurality of yarn supplying bobbins
to form one package while removing a yarn defect such as slub.
An automatic winder of Japanese Unexamined Patent Publication
15 No. 2009-242036 includes a bobbin supporting section adapted to
support a yarn supplying bobbin, a package forming device adapted
to wind the yarn unwound from the yarn supplying bobbin around a core
tube while traversing the yarn to form a package, and a yarn joining
device adapted to join a yarn from the package and a yarn from the
20 yarn supplying bobbin at the time of replacing the yarn supplying
bobbin, after carrying out a yarn cutting operation to remove a yarn
defect, or after occurrence of an unexpected yarn breakage. A
configuration for carrying out the yarn joining operation by the yarn
joining device includes two yarn end catching members connected to
25 a negative pressure source and adapted to individually suck and catch
a yarn end from the package and a yarn end from the yarn supplying
bobbin and transport the yarn ends to the yarn joining device.
As disclosed in Japanese Unexamined Patent Publication No.
2009-242042 , there is known an automatic winder including a yarn
30 accumulating device (accumulator) arranged between the package
forming device and the yarn joining device and adapted to wind the
yarn unwound from the yarn supplying bobbin to temporarily accumulate
the yarn. In the automatic winder of Japanese Unexamined Patent
Publication No. 2009-242042, the yarn end from the yarn accumulating
35 device and the yarn end from the yarn supplying bobbin are respectively
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caught with a yarn end catching member and transported to the yarn
4It joining device at the time of replacing the yarn supplying bobbin,
after the cutting of the yarn, or after the yarn breakage, thus
performing the yarn joining operation by the yarn joining device.
5 In order that the yarn end from the -yarn accumulating device is easily
caught by the yarn end catching member, the yarn accumulating device
includes a pull-out mechanism adapted to pullout the yarn end pulled
into the yarn accumulating device. In the automatic winder of
Japanese Unexamined Patent Publication No. 2009-242042, since the
10 yarn accumulated in the yarn accumulating device is unwound and
supplied to the package forming device while the yarn joining
operation is being carried out, the winding of the package can be
continuously carried out without being interrupted.
When the yarn of the yarn supplying bobbin is all unwound, a
15 new yarn supplying bobbin is supplied, and then the yarn end unwound
from the previous yarn supplying bobbin and the yarn end of the yarn
supplying bobbin supplied next are joined by the yarn joining device.
In this case, it may be difficult to catch the yarn end (yarn end
from the package) unwound from the previous yarn supplying bobbin
20 by the yarn end catching member. For example, in the automatic winder
of Japanese Unexamined Patent Publication No. 2009-242036, when the
yarn of the yarn supplying bobbin is all unwound, the yarn end may
strongly attach to the surface of the package. Alternatively, the
yarn may be flipped to a position greatly distant from a predetermined
25 position where the yarn end catching member sucks and catches the
yarn end. In such cases, the yarn end becomes difficult to catch.
Similar problems occur in the automatic winder of Japanese
Unexamined Patent Publication No. 2009-242042 including a yarn
accumulating device between the yarn supplying bobbin and the package.
30 That is, the yarn end unwound from the yarn supplying bobbin is
sometimes pulled into the yarn accumulating device and may bite into
the yarn layer. Alternatively, the yarn end unwound from the yarn
supplying bobbin may be flipped to a position distant from the
predetermined position. In such cases, the yarn end becomes
35 difficult to pullout by the pull-out mechanism, and the yarn end
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becomes difficult to catch. The operation of the operator thus
becomes necessary if the yarn end cannot be automatically caught by
the yarn end catching member. Since this requires the winding
operation of the package to be stopped, package production efficiency
is lowered.
BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to improve catching
probability of a yarn end unwound from a previous yarn supplying bobbin
10 at the time of replacing the yarn supplying bobbin.
A yarn winding device of the present invention includes a bobbin
supporting section adapted to support a yarn supplying bobbin; a
winding section adapted to wind a yarn unwound from the yarn supplying
bobbin; a yarn amount detecting section adapted to detect an amount
15 of yarn of the yarn supplying bobbin; a control section adapted to
control a winding speed of the winding section; and a yarn state
detecting section adapted to detect a state of a travelling yarn,
wherein the control section predicts end of unwinding of the yarn
of the yarn supplying bobbin based on a detection result of the yarn
20 amount detecting section, and decelerates the winding speed of the
winding section to stop the winding operation of the winding section
before a yarn end reaches the winding section based on the detection
result of the yarn state detecting section after the end of unwinding
of the yarn from the yarn supplying bobbin.
25 According to the present invention, the end of unwinding of the
yarn of the yarn supplying bobbin is predicted from the detection
result of the yarn amount detecting section, and the winding is
decelerated and stopped before the yarn end reaches the winding
section when the unwinding of the yarn from the yarn supplying bobbin
30 is finished. Therefore, the yarn end of the yarn unwound from the
yarn supplying bobbin becomes easy to catch.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of one winding unit of an automatic winder
35 according to the present invention;
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FIG. 2 is a side view of a yarn accumulating device;
FIG. 3A is a view describing a yarn amount detecting section
shortly before end of unwinding of the yarn;
FIG. 3B is a view describing the yarn amount detecting section
immediately before the end of unwinding of the yarn;
FIG. 4 is a flowchart describing a series of processing steps
performed at the time of replacing a yarn supplying bobbin;
FIG. 5 show graphs illustrating a deceleration profile of a yarn
accumulating roller of one embodiment of the present invention and
the remaining amount of yarn of the yarn supplying bobbin; and
FIG. 6 is a side view of a winding unit according to an
alternative embodiment.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
15 An embodiment of the present invention will be described below.
The present embodiment is an example in which the present invention
is applied to an automatic winder including a plurality of winding
units (yarn winding devices), adapted to wind a yarn unwound from
a yarn supplying bobbin to form a winding package. The automatic
20 winder has a configuration in which the plurality of winding units,
each forming one package, is arranged in a line in one direction.
FIG. 1 is a side view of one winding unit 1 of the automatic winder.
As illustrated in FIG. 1, each winding unit (yarn winding
device) 1 includes a bobbin supplying device 2, a bobbin supporting
25 section 3, a package winding device 4, and a unit control section
5 for controlling each section of the winding unit 1. With a yarn
supplying bobbin 8 supplied from the bobbin supplying device 2 being
held by the bobbin supporting section 3, the winding unit 1 winds
a spun yarn Y unwound from the yarn supplying bobbin 8 around a winding
30 tube 6 while traversing the spun yarn Y to form a package P of a
predetermined shape.
The bobbin supplying device 2 includes a rotary magazine 10
capable of holding a plurality of extra yarn supplying bobbins 8.
When the magazine 10 is intermittently rotated, one yarn supplying
35 bobbin 8 out of the plurality of yarn supplying bobbins held in the
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magazine 10 is dropped diagonally so that the yarn supplying bobbin
8 is supplied to the bobbin supporting section 3.
The bobbin supporting section 3 holds the yarn supplying bobbin
8 in a replaceable manner. Specifically, the yarn supplying bobbin
8 supplied from the bobbin supplying device 2 is held in a
substantially upright state by a bobbin holding tool (not illustrated)
inserted to a lower end of the yarn supplying bobbin 8. When the yarn
of the yarn supplying bobbin 8 is all unwound and the yarn supplying
bobbin 8 becomes empty (state in which yarn is not wound), the bobbin
supporting section 3 can flip up the yarn supplying bobbin 8 by a
springboard 11 to discharge the yarn supplying bobbin 8 outside the
bobbin supporting section 3. The bobbin supporting section 3 also
includes a yarn amount detecting section 12 (yarn amount detecting
section) adapted to detect an amount of yarn of the yarn supplying
bobbin 8. The details of the yarn amount detecting section 12 will
be described later.
On a yarn travelling path between the bobbin supporting section
3 and the package forming device 4, an unwinding assisting device
15, a lower yarn blow-up device 16, a tension applying device 17,
an upper yarn catching device 18, a yarn joining device 19, a lower
yarn catching device 20, a clearer 21 serving as a yarn defect
detecting device, and a yarn accumulating device (winding section)
22 are arranged in this order from the bobbin supporting section 3.
The unwinding assisting device 15 lowers a tube body 30, which
covers an upper end of the yarn supplying bobbin 8, with advancement
in the unwinding of the yarn Y to regulate bulging (balloon) of the
yarn Y during the unwinding and stabilize the unwinding tension.
The lower yarn blow-up device 16 is connected to a compressed
air source (not illustrated), and is configured to generate an upward
airflow at the time of the yarn joining operation to blow up a lower
yarn Y2 from the yarn supplying bobbin 8 towards the yarn joining
device 19.
The tension applying device 17 is adapted to apply a
predetermined tension on the travelling yarn Y. The tension applying
device 17 may be, for example, a gate-type which includes fixed comb
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teeth and movable comb teeth movably arranged with respect to the
fixed comb teeth.
The upper yarn catching device 18 (first yarn end catching
section) is connected to a negative pressure source (not illustrated) .
The negative pressure source is adapted to generate a suction airflow
during the yarn joining operation to suck and catch an upper yarn
Yl from the yarn accumulating device 22 guided by a guide member 32,
to be described later.
The lower yarn catching device 20 (second yarn end catching
section) is connected to the negative pressure source (not
illustrated), and catches the lower yarn Y2 blown up by the lower
yarn blow-up device 16 at the time of the yarn joining operation.
The yarn joining device 19 joins the lower yarn Y2 from the yarn
supplying bobbin 8 and the upper yarn Yl from the winding side (yarn
accumulating device 22) at the time of replacing the yarn supplying
bobbin 8, after yarn cut carried out when the clearer 21, described
later, detects a yarn defect, or after yarn breakage during the
unwinding of the yarn from the yarn supplying bobbin 8. The yarn
joining device 19 may be the yarn joining device 19 (air splicer)
including an untwisting nozzle adapted to untwist the yarn end of
the upper yarn Yl and the yarn end of the lower yarn Y2, and a twisting
nozzle adapted to apply a whirling airflow on the untwisted yarn ends
to twist the yarn ends.
The clearer 21 (yarn defect detecting device) is arranged on
the yarn travelling path between the bobbin supporting section 3 and
the yarn accumulating device 22, and detects a yarn defect such as
slub of the yarn Y travelling through the yarn travelling path. The
clearer 21 is provided with a cutter 31 for cutting the yarn when
the yarn defect is detected.
The substantially tubular guide member 32 is arranged on the
side of the yarn joining device 19 between the upper yarn catching
device 18 and the yarn accumulating device 22 so as to circumvent
a linear yarn travelling path during normal winding. Furthermore,
a slit 32a is formed over the entire length of the guide member 32
in a side wall of the guide member 32 on the left side in the figure
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(yarn travelling path side).
At the time of the yarn joining operation, the upper yarn Y1
from the yarn accumulating device 22 is pulled out by an upper yarn
pull-out device of the yarn accumulating device 22, to be described
5 later, and fed to the guide member 32, and the yarn end of the upper
yarn Y1 is passed through the guide member 32 to be caught by the
upper yarn catching device 18. Furthermore, when the yarn is pulled
by the upper yarn catching device 18, the yarn is pulled out to the
outside of the guide member 32 through the slit 32a and guided to
10 the yarn joining device 19. The lower yarn Y2 from the yarn supplying
bobbin 8 is blown upward by the lower yarn blow-up device 16. Moreover,
the blown-up yarn is caught and pulled by the lower yarn catching
device 2a to be guided to the yarn joining device 19. After the upper
yarn Y1 and the lower yarn Y2 are set in the yarn joining device 19
15 in this manner, the yarn joining device 19 joins the upper yarn Y1
and the lower yarn Y2.
The yarn accumulating device 22 is a winding section adapted
to wind the yarn Y unwound from the yarn supplying bobbin 8 to
temporarily accumulate the yarn. The details on the structure of the
20 yarn accumulating device 22 will be described later.
The package forming device 4 includes a cradle 33 which has a
pair of cradle arms for rotatably and detachably supporting the
winding tube 6, and a traverse drum 34 which can make contact with
the surface of the winding tube 6 supported by the cradle 33 or the
25 surface of the package P formed on the winding tube 6. The package
forming device 4 is rotated by a drum drive motor (not illustrated)
with the traverse drum 34 making contact with the winding tube 6 (or
the surface of the package P). The package forming device 4 is
configured such that the winding tube 6 is rotated (accompanying
30 rotation) accompanying the rotation of the traverse drum 34 while
traversing the yarn unwound from the yarn accumulating device 22,
to form the package P on an outer periphery of the winding tube 6.
In place of the traverse drum 34, an arm traverse mechanism including
a yarn traverse arm for holding and swinging the yarn to traverse
35 the yarn may be adopted for the package forming device 4. When the
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arm traverse mechanism is adopted, a configuration in which a package
drive motor for directly rotating the package is arranged in the cradle
33 may also be adopted instead of the drum drive motor.
In the present embodiment, the yarn accumulating device 22
5 adapted to accumulate the yarn Y is arranged between the bobbin
supporting section 3 and the package forming device 4. Even if the
unwinding of the yarn from the yarn supplying bobbin 8 is interrupted
for some reason (e. g., during the yarn joining operation by the yarn
joining device 19), the package forming device 4 can wind the yarn
10 accumulated in the yarn accumulating device 22. Thus, the winding
of the package P can be continued even if the unwinding of the yarn
from the yarn supplying bobbin 8 is interrupted.
The unit control section 5 (control section) is configured by
a CPU (Central Processing Unit) which is an arithmetic processing
15 unit, a ROM (Read-Only Memory) which stores programs executed by the
CPU and data used in the program, a RAM (Random Access Memory) which
temporarily stores the data during the execution of the program, an
input/output interface for inputting and outputting data from and
to outside. The unit control section 5 controls the operation of each
20 device of the above-described winding unit 1 based on a command sent
from a machine control device (not illustrated), which performs the
overall control of the automatic winder.
Next, the yarn accumulating device 22 will be described in
detail. FIG. 2 is a side view of the yarn accumulating device 22.
25 As illustrated in FIG. 1 and FIG. 2, the yarn accumulating device
22 includes a yarn accumulating roller 40 adapted to wind and
accumulate the yarn, a roller driving motor 41 which rotatably drives
the yarn accumulating roller 40, and an upper yarn pull-out device
42 which pulls out the yarn end of the yarn wound around the yarn
30 accumulating roller 40 at the time of the yarn joining operation.
As illustrated in FIG. 2, the yarn accumulating roller 40 is
rotatably supported on the machine bed of the winding unit 1 with
an axis C1, which is slightly tilted with respect to a horizontal
direction, asa center. Tapered portions 40a, 40b, with a diameter,
35 which becomes larger towards the end, are formed at both axial ends
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of the yarn accumulating roller 40 , respectively. The portion
between the two tapered portions 40a, 40b is a cylindrical portion
40c having a constant diameter, and the yarn Y is wound around the
cylindrical portion 40c. The yarn Y wound around the cylindrical
portion 40c is prevented from falling off by the two tapered portions
40a, 40b at both ends. The outer surface of the cylindrical portion
40c may be formed in a gradually tapered shape.
The roller driving motor 41 is attached to a basal end (end on
the left side in the figure) of the yarn accumulating roller 40. The
roller driving motor 41 is a position controllable motor such as a
DC brushless motor, a stepping motor, a servo motor, and the like,
and can rotatably drive the yarn accumulating roller 40 in both
directions.
A guide tube 43 which constitutes one part of the upper yarn
pull-out device 42, to be described later, is arranged in proximity
to the tapered portion 40a on the basal end side of the yarn
accumulating roller 40. One end of the guide tube 43 is arranged close
to the surface of the yarn accumulating roller 40. At the time of
the normal winding, the yarn from the yarn supplying bobbin 8 is guided
to the tapered portion 40a on the basal end side of the yarn
accumulating roller 40 through the guide tube 43.
When the yarn accumulating roller 40 is rotated in one direction,
the yarn Y guided to the tapered portion 40a on the basal end side
of the yarn accumulating roller 40 by the guide tube 43 is sequentially
wound while pushing up the previous yarn layer from the basal end
side (left side in the figure) of the cylindrical portion 40c. As
a result, the yarn that ~s already wound around the yarn accumulating
roller 40 is pushed by the newly wound yarn, and is sequentially fed
towards the distal end side. The yarn is thus spirally aligned and
orderly wound from the basal end side on the outer peripheral surface
of the cylindrical portion 40c of the yarn accumulating roller 40.
Meanwhile, the yarn wound around the yarn accumulating roller
40 is pulled out from the tapered portion 40b on the distal end side
(right side in the figure) of the yarn accumulating roller 40, and
is fed downstream (towards the package forming device 4). At the
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tapered portion 40b on the distal end side, the yarn on the yarn
accumulating roller 40 is pulled out towards the downstream through
a pull-out guide 44, which is positioned on an extended line of the
center axis C1 of the yarn accumulating roller 40.
A rubber annular member 45 such as a rubber band, an 0 ring,
or the like is attached to the distal end of the cylindrical portion
40c of the yarn accumulating roller 40 (boundary portion with the
distal end side tapered portion 40b). The yarn wound around the yarn
accumulating roller 40 is passed between the yarn accumulating roller
40 and the annular member 45 to be unwound, whereby an appropriate
tension is applied on the unwinding yarn. The annular member 45 is
prevented from falling off from the yarn accumulating roller 40 by
the tapered portion 40b on the distal end side of the yarn accumulating
roller 40.
An upper limit sensor 46 for detecting that the amount of yarn
on the yarn accumulating roller 40 is greater than or equal to a
predetermined upper limit amount, and a lower limit sensor 47 for
detecting that the amount of yarn is smaller than a predetermined
lower limit amount are arranged in proximity of the outer peripheral
surface of the cylindrical portion 40c of the yarn accumulating roller
40. The detection results of the upper limit sensor 46 and the lower
limit sensor 47 are sent to the unit control section 5. Based on the
detection results of the sensors 46, 47, the unit control section
5 controls the roller driving motor 41 such that the yarn accumulating
amount (winding amount) of the yarn accumulating roller 40 is within
a range between the upper limit amount and the lower limit amount.
The upper yarn pull-out device 42 is a device for pulling out
the yarn end of the yarn from the yarn accumulating device 22 (upper
yarn Y1) to perform the yarn joining operation by the yarn joining
device 19 at the time of replacement of the yarn supplying bobbin
8, after the cutting of the yarn, or after the yarn breakage when
the yarn defect is detected. The upper yarn pull-out device 42
includes the guide tube 43 mentioned above. A yarn passage 50 and
a nozzle 51 connected to the yarn passage 50 are formed inside the
guide tube 43. One end of the guide tube 43 faces the tapered portion
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40a on the basal end side of the yarn accumulating roller 40, and
the above-described guide member 32 is arranged at the other end of
the guide tube 43 with its opening at the upper end facing the guide
tube 43. The nozzle 51 is connected to a compressed air source 52,
and an electromagnetic valve 53 that opens and closes by a signal
from the unit control section 5 is arranged between the nozzle 51
and the compressed air source 52.
At the time of the normal winding, the yarn unwound from the
yarn supplying bobbin 8 is passed through the yarn passage 50 of the
guide tube 43 and guided to the surface of the yarn accumulating roller
40. At the time of the yarn joining operation, the electromagnetic
valve 53 is switched from close to open, and the compressed air is
supplied from the nozzle 51 into the yarn passage 50, so that the
airflow directed from the yarn accumulating roller 40 towards the
guide member 32 is generated in the yarn passage 50. Under this state,
when the yarn accumulating roller 40 is rotated opposite to the
rotation at the time of normal winding, the yarn on the yarn
accumulating roller 40 is unwound from the basal end side, and the
yarn end thereof is pulled into the guide tube 43 by the airflow and
further fed from the guide tube 43 to the guide member 32. The yarn
end of the upper yarn Yl fed to the guide member 32 in this manner
is guided to and caught by the above-described upper yarn catching
device 18, whereby the upper yarn Yl is led to the yarn joining device
19.
The upper yarn Yl is pulled out from the yarn accumulating device
22 by the upper yarn pull-out device 42 during the yarn joining
operation, but the yarn end of the upper yarn Yl is wound around the
yarn accumulating roller 40 when the unwinding of the yarn supplying
bobbin 8 is finished. If the tension of the yarn immediately before
the end of unwinding is large, the yarn end of the upper yarn Yl may
bite into the yarn layer of the yarn accumulating roller or may be
flipped to a position greatly distant from the original position
(proximate position of the tapered portion 40a on the basal end side)
sucked by the guide tube 43. In such cases, the catching (pulling
out) of the yarn end by the upper yarn pull-out device 42 and the
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upper yarn catching device 18 becomes difficult.
The winding unit 1 of the present embodiment is thus devised
to easily catch the yarn end of the upper yarn Yl from the yarn
accumulating device 22 unwound from the previous yarn supplying bobbin
8 particularly during the yarn joining operation after the yarn
supplying bobbin 8 is replaced. Specifically, the amount of yarn of
the yarn supplying bobbin 8 is detected to predict that the end on
unwinding of the yarn is close, and the rotation speed (winding speed)
of the yarn accumulating roller 40 of the yarn accumulating device
22 is decelerated prior to the end of the unwinding of the yarn.
Thereafter, when the yarn is all unwound from the yarn supplying bobbin
8, the yarn accumulating roller 40 is stopped from the decelerating
state. By once decelerating and then stopping the yarn accumulating
roller 40 in this manner, the yarn end of the upper yarn Yl can be
prevented from being wound around the yarn accumulating roller 40.
Since this deceleration lowers the tension of the yarn immediately
before the end of unwinding of the yarn, the yarn end is prevented
from biting into the yarn layer of the yarn accumulating roller 40
or from being flipped to a distant position.
The control of the yarn accumulating roller 40 at the time of
replacing the yarn supplying bobbin 8 will be described below. Before
this, the yarn amount detecting section 12 for detecting the yarn
amount to predict the end of unwinding of the yarn of the yarn supplying
bobbin 8 will be described. In order to perform the deceleration of
the yarn accumulating roller 40, the yarn amount detecting section
12 desirably has a configuration of detecting, at an early stage,
the state immediately before the end of unwinding of the yarn in which
the amount of yarn of the yarn supplying bobbin 8 is less than a
predetermined amount, so that the deceleration is performed in time.
One example of such a configuration will be described below.
FIG. 3A and 3B are views describing the yarn amount detecting
section 12. As illustrated in FIG. 3A and 3B, the yarn amount
detecting section 12 includes reflective photosensors 55a and 55b
including a light emitting section for irradiating light toward the
yarn supplying bobbin 8 and a light receiving section for receiving
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the reflected light. The reflectivity of the surface of the yarn
supplying bobbin 8 differs between a state in which the yarn layer
is present and a state in which the yarn layer is absent at the light
irradiating position of the yarn supplying bobbin 8. Therefore,
detection is made that the yarn layer is absent at a predetermined
detection position from the change in the light receiving amount of
the light receiving section of the photosensors 55a and 55b, so that
the region where the yarn is wound on the surface of a core tube 54
becomes significantly small, and a state in which the yarn amount
is less than a predetermined amount (i.e., state immediately before
the end of unwinding of the yarn) can be detected.
The yarn amount detecting section 12 includes two photosensors
55a, 55b arranged spaced apart in an axial direction (vertical
direction) of the yarn supplying bobbin 8 to respectively detect the
yarn at two detecting positions on the surface of the yarn supplying
bobbin 8 (core tube 54). Thus, by detecting the presence or absence
of the yarn layer at two detecting positions in the vertical direction
of the yarn supplying bobbin 8 by the two photosensors 55a, 55b, the
state immediately before the end of unwinding of the yarn is less
likely to be overlooked.
In particular, as illustrated in FIG. 3A, the thickness of the
yarn layer is not uniformly made thin within a range of the lower
end of the core tube 54 immediately before the end of unwinding of
the yarn, but as illustrated in FIG. 3B, the state immediately before
the end of unwinding of the yarn is less likely to be overlooked if
there is more than one photosensor 55a or 55b when the yarn unwound
lastly is left as a lump at an unspecified position at the lower end
of the core tube 54.
One of the reasons for the occurrence of the state in which the
yarn unwound lastly is left as a lump is that when the yarn supplying
bobbin 8 is produced by the fine spinning machine, in particular,
when the operator starts winding after manually hooking the yarn on
the core tube 54, the yarn at the beginning of the winding tends to
be wound in a lump at the first yarn hooking position. Furthermore,
when the operator manually hooks the yarn, the yarn hooking position
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on the core tube 54 may shift in the axial direction, and if the yarn
is unwound from such a yarn supplying bobbin 8 by the winding unit
1, the position of the lump of yarn left immediately before the end
of unwinding may differ. That is, a lump 56 of yarn is not left at
a specific position but can be formed at various positions on the
lower end of the core tube 54.
Therefore, as illustrated in FIG. 3B, there may occur a state
where the lump 56 of yarn is left only at the detecting position of
the photosensor 55a and the yarn is hardly left at other portions.
In this case, if there is only one photosensor 55a or 55b,
determination may be wrongly made that sufficient amount of yarn is
still left on the yarn supplying bobbin 8 even though only a very
small amount of yarn is actually left on the yarn supplying bobbin
8 (only the lump 56 exists). When the lump 56 of yarn that is left
last is unwound from such a state, the unwinding of the yarn of the
yarn supplying bobbin 8 is immediately terminated and a state in which
a small amount of yarn is left cannot be detected in advance before
the end of unwinding of the yarn.
In the present embodimeot, two photosensors 55a, 55b are used,
and the unit control section 5 determines that the yarn of the yarn
supplying bobbin 8 is less than a predetermined amount when at least
one of the two photosensors 55a, 55b detects that there is no yarn
at the detecting position. In other words, even if the yarn unwound
last exists in a lump form at the detecting position of one of the
sensors 55a, 55b, the yarn of the yarn supplying bobbin 8 is determined
to be less than the predetermined amount if there is no yarn at the
detecting position of the other sensor 55b or 55a. According to such
a configuration, a state in which only the lump 56 of yarn is left
on the core tube can be detected in advance before the end of unwinding
of the yarn.
The number of photosensors of the yarn amount detecting section
12 is not limited to two, and three or more sensors may be arranged
with a spacing in the vertical direction. In this case as well, the
yarn of the yarn supplying bobbin 8 is determined to be less than
the predetermined amount when at least one of the photosensors detects
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that there is no yarn.
A series of processing in replacing the yarn supplying bobbin
during package winding will be described. FIG. 4 is a flowchart
describing the processing. In FIG. 4, Si (i = 10, 11, 12 ... ) indicates
a step number.
During the package winding, the yarn unwound from the yarn
supplying bobbin 8 is wound and accumulated by the yarn accumulating
device 22, and the yarn unwound from the yarn accumulating device
22 is wound around the winding tube 6 in the package forming device
4. In this case, the package forming device 4 and the yarn
accumulating device 22 respectively wind the yarn at a high winding
speed (hereinafter referred to as winding speed during normal winding)
of greater than or equal to a prescribed winding speed. While the
winding of the package P is being carried out in such a manner, the
amount of yarn of the yarn supplying bobbin 8 is detected by the yarn
amount detecting section 12 of the bobbin supporting section 3 (S10:
yarn amount detecting step). When a state in which the amount of yarn
of the yarn supplying bobbin 8 is less than the predetermined amount
is detected by the yarn amount detecting section 12 (S10: Yes),
determination is made that the end of unwinding of the yarn of the
yarn supplying bobbin 8 is close, and the unit control section 5
controls the roller driving motor 41 to greatly decelerate the
rotation speed (winding speed) of the yarn accumulating roller 40
from the winding speed during the normal winding (Sll: decelerating
step). This decelerating state is maintained until the yarn left on
the yarn supplying bobbin 8 is all unwound.
In the present embodiment, the clearer 21 (yarn defect detecting
device) is used as a yarn state detecting section for detecting the
end of unwinding of the yarn of the yarn supplying bobbin 8. That
is, the unit control section 5 can reliably grasp whether or not the
yarn of the yarn supplying bobbin 8 is all unwound by detecting the
presence or absence of the travelling yarn by the clearer 21. In the
normal package winding operation of the winding uni t 1, the detection
signal of the clearer 21 for detecting the yarn defect is used for
the detection of the end of unwinding of the yarn of the yarn supplying
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bobbin 8, and thus a dedicated detecting section for detecting the
end of unwinding of the yarn becomes unnecessary.
When the clearer 21 detects that the travelling yarn has run
out (812: Yes), the unit control section 5 stops the rotation of the
yarn accumulating roller 40 (813: stopping step). As described above,
since the winding speed of the roller 40 is decelerated before the
yarn accumulating roller 40 is stopped, a time required after the
end of unwinding of the yarn is detected by the clearer 21 and until
the yarn accumulating roller 40 is completely stopped becomes shorter.
Therefore, the yarn accumulating roller 40 can be stopped before
the yarn end unwound last from the yarn supplying bobbin 8 reaches
the yarn accumulating roller 40. Even if the yarn end is wound by
the yarn accumulating roller 40, the yarn end is less likely to bite
into the yarn layer of the yarn accumulating roller 40 since the
tension of the yarn is reduced by the deceleration before the end
of unwinding of the yarn. Also, the yarn end is not flipped to a
position distant from the position (position of the tapered portion
40a of the basal end portion) where the yarn end is pulled out by
the upper yarn pull-out device 42. Therefore, the yarn end of the
yarn unwound from the yarn supplying bobbin 8 is easily pulled out
and caught by the upper yarn pull-out device 42 in the following yarn
joining processing (815). Thus, the success rate of the yarn joining
operation with the lower yarn Y2 (yarn of the newly supplied yarn
supplying bobbin 8) performed by the yarn joining device 19 increases.
Furthermore, in the control described above, the deceleration
control of the yarn accumulating roller 40 in 811 of FIG. 4 is
preferably carried out such that the speed is obtained at which the
yarn end is always not wound around the yarn accumulating roller 40
when the unwinding of the yarn of the yarn supplying bobbin 8 is
finished. For example, the distance along the yarn travelling path
between the clearer 21 and the yarn accumulating roller 40 is known
since it can be determined from the position relationship of the
clearer 21 and the yarn accumulating roller 40. Therefore, in 811,
the speed of the yarn accumulating roller 40 is decelerated to a speed
lower than or equal to a speed at which the rotation of the yarn
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accumulating roller 40 can be stopped before the yarn travels the
4It above distance after passing the clearer 21 and reaches a position
near the yarn end pull-out position (tapered portion 40a on the basal
end side) of the yarn accumulating roller 40. Thus, by stopping the
5 yarn accumulating roller 40 before the yarn end of the yarn supplying
bobbin 8 reaches the yarn accumulating roller 40a, state is obtained
in which the yarn end is always outside the yarn accumulating device
22 and the yarn end can be very easily caught.
When decelerating the winding speed of the yarn accumulating
10 roller 40 in Sll, the winding speed of the package forming device
4 (rotation speed of the traverse drum 34) may be decelerated at the
same time. Therefore, sudden reduction in the yarn amount
accumulated in the yarn accumulating roller 40 can be avoided, and
the yarn accumulated in the yarn accumulating device 22 can be
15 prevented from running out.
After the unwinding of the yarn of the yarn supplying bobbin
8 is finished, the yarn supplying bobbin 8 supported by the bobbin
supporting section 3 of FIG. 1 is replaced (S14). Specifically, the
bobbin supporting section 3 first flips the empty yarn supplying
20 bobbin 8 by the springboard 11 to discharge this empty bobbin. The
bobbin supplying device 2 then drops the yarn supplying bobbin 8
accommodated in the magazine 10 to the bobbin supporting section 3,
and the bobbin supporting section 3 receives the dropped yarn
supplying bobbin 8 and supports the yarn supplying bobbin 8 in a
25 substantially upright position.
After the replacement of the yarn supplying bobbin 8 is
completed, the yarn joining operation is performed by the yarn joining
device 19 (S15). With respect to the lower yarn Y2 from the newly
supplied yarn supplying bobbin 8, the yarn end blown up by the lower
30 yarn blow-up device 16 illustrated in FIG. 1 is caught by the lower
yarn catching device 20 so that the lower yarn Y2 is guided to the
yarn joining device 19. The upper yarn Y1 is pulled out by the upper
yarn pull-out device 42 illustrated in FIG. 1 and FIG. 2, and the
upper yarn Y1 fed to the guide member 32 is caught by the upper yarn
35 catching device 18 so that the upper yarn Y1 is guided to the yarn
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joining device 19. The lower yarn Y2 and the upper yarn Y1 are then
joined by the yarn joining device 19 to form one yarn. After the yarn
joining operation is finished, the unit control section 5 again
rotates the yarn accumulating roller 40 to resume the winding of the
yarn (accumulation of the yarn) to the roller 40 (816).
During the replacing processing of the yarn supplying bobbin
8 and the yarn joining processing described above, the yarn
accumulated in the yarn accumulating device 22 is unwound and fed
into the package forming device 4, so that the winding of the package
P is continuously carried out without being interrupted even during
such processing, whereby the production efficiency of the package
P is improved. However, if the yarn joining operation by the yarn
joining device 19 fails, the time during which the yarn of the yarn
accumulating device 22 is continuously wound without the yarn from
the yarn supplying bobbin 8 being supplied becomes long by that much.
Therefore, if the success rate of the yarn joining operation is low
and the yarn joining operation fails in succession, the yarn of the
yarn accumulating device 22 eventually runs out and the winding
operation of the package P may be inevitably stopped. From this
standpoint, the significance of easily catching the yarn end of the
upper yarn Y1 and increasing the success rate of the yarn joining
operation is great.
(Embodiment) A specific embodiment of the deceleration and stop
control of the yarn accumulating device 22 when replacing the yarn
supplying bobbin described above will be described. FIG. 5 shows
graphs illustrating a deceleration profile of a yarn accumulating
roller of one embodiment of the present invention and transition of
remaining amount of yarn of the yarn supplying bobbin.
In this embodiment, the yarn accumulating roller 40 winds the
yarn at the winding speed of 1500 m/min during the normal package
winding. From this state, when the amount of yarn of the yarn
supplying bobbin 8 becomes less than the predetermined amount (16
m herein as illustrated in the lower graph) according to the yarn
amount detecting section 12 (point A in the upper graph), the winding
speed of the yarn accumulating roller 40 is promptly decelerated from
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1500 m/min to 200 m/min (deceleration: 2600 m/min/sec) in 0.5 seconds
(point B). As is apparent from the lower graph, the yarn of about
7 m is unwound from the yarn supplying bobbin 8 during the deceleration.
Thereafter, the winding is continued at a low speed of 200 m/min,
and when a state is detected in which the yarn of the yarn supplying
bobbin 8 has run out (end of unwinding of yarn) (point C) by the clearer
21 serving as the yarn state detecting section, the rotation of the
yarn accumulating roller 40 is stopped (point 0). Note that from point
B to point C, the remaining yarn of about 9 m is unwound from the
yarn supplying bobbin 8 by the unwinding at a prescribed speed (200
m/min) .
It takes 0.08 seconds from the detection of the end of unwinding
of the yarn by the clearer 21 (point C) until the yarn accumulating
roller 40 is completely stopped (point 0), and the yarn amount wound
by the yarn accumulating roller 40 during this time is about 12 cm.
Therefore, if the distance from the clearer 21 to the yarn accumulating
roller 40 (distal end of guide tube 43 of upper yarn pull-out device
42) is greater than or equal to 12 cm, the yarn end stops without
being pulled into the yarn accumulating roller 40. On the other hand,
if the distance is less than 12 cm, the deceleration from point A
to point B is to be set to a speed lower than 200 m/min.
An alternative embodiment in which various modifications are
applied on the above embodiment will be described below. Portions
having the configuration similar to the embodiment described above
are denoted with the same reference numerals, and the description
thereof will be appropriately omitted.
1) In the above embodiment, after the yarn accumulating roller
40 is decelerated, detection is made that the yarn is all unwound
from the yarn supplying bobbin 8 by a yarn absent detection signal
of the clearer 21 (yarn defect detecting device). However, the yarn
state detecting section for detecting the end of unwinding of the
yarn may have a configuration other than the clearer 21.
The winding unit of the automatic winder may include a yarn state
detecting device adapted to detect various states of the travelling
yarn other than the clearer 21. For example, the yarn state detecting
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device may be a yarn presence/absence detecting device for detecting
presence or absence of the travelling yarn, a yarn speed detecting
device for detecting a speed of the travelling yarn, a yarn length
detecting device for detecting the length of the traveling yarn, a
yarn tension detecting device for detecting the tension of the
travelling yarn, and the like. Such devices may be caused to perform
detection as the yarn state detecting section, and the yarn
accumulating roller 40 in the decelerating state may be stopped when
detected that there is no longer yarn on the yarn travelling path.
In this case as well, similarly to the embodiment using the clearer
21, the end of unwinding of the yarn of the yarn supplying bobbin
8 is detected using various detecting devices for detecting the state
of the yarn in the normal winding operation of the winding unit. Thus,
a dedicated detecting section for detecting the end of unwinding of
the yarn becomes unnecessary.
Alternatively, the yarn amount detecting section 12 may be
configured to.not only detect that the amount of yarn of the yarn
supplying bobbin 8 is less than the predetermined amount, but also
to detect a state in which the unwinding of the yarn is finished and
the yarn of the yarn supplying bobbin 8 has completely run out.
According to such a configuration, the yarn accumulating roller 40
can be stopped by the detection of the end of unwinding of the yarn
by the yarn amount detecting section 12.
For example, the sensor constituting the yarn amount detecting
section 12 may be a so-called area sensor adapted to detect the
presence or absence of the yarn existing within a predetermined range
in the surface of the yarn supplying bobbin 8. If the area sensor
is adopted, detection can be made not only that the amount of yarn
of the yarn supplying bobbin 8 is less than the predetermined amount,
but also a state in which the yarn of the yarn supplying bobbin 8
has completely run out. According to another example, a state can
be detected in which the yarn of the yarn supplying bobbin 8 has all
run out when the yarn amount detecting section 12 is configured by
a camera for imaging the surface of the yarn supplying bobbin 8 and
an image analyzer for analyzing the image captured by the camera.
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In such configuration examples, since the start of deceleration and
stopping of winding of the yarn accumulating roller 40 are carried
out based on the detection resul t of one yarn amount detecting section
12, a special detecting section for detecting the end of unwinding
5 of the yarn is not necessary.
2) The above embodiment is an example in which the present
invention is applied to the winding uni t having the yarn accumulating
device 22, but application can be made to a winding unit having a
configuration in which the yarn accumulating device 22 is not arranged,
10 that is, a configuration in which the yarn unwound from the yarn
supplying bobbin 8 is directly wound by the package forming device
4 to form the package P.
FIG. 6 illustrates a side view of the winding unit described
above. As illustrated in FIG. 6, in a winding uni t lA, the unwinding
15 assisting device 15, the tension applying device 17, the yarn joining
device 19, and the clearer 21 are arranged in order from the bobbin
supporting section 3 on the yarn travelling path between the bobbin
supporting section 3 and the package forming device 4. The yarn
accumulating device 22 of the above embodiment is not arranged between
20 the clearer 21 and the package forming device 4, and the yarn Y that
passed through the clearer 21 is directly wound by the package forming
device 4.
In the winding unit 1A of FIG. 6, a configuration of guiding
the yarn end of the upper yarn Y1 from the package forming device
25 4 and the yarn end of the lower yarn Y2 from the yarn supplying bobbin
8 respectively to the yarn joining device 19 during the yarn joining
operation is slightly different from the above embodiment. An upper
yarn catching and guiding pipe 60 (first yarn end catching section)
for sucking and catching the upper yarn Y1 from the package P and
30 guiding the upper yarn Y1 to the yarn joining device 19 and a lower
yarn catching and guiding pipe 61 (second yarn end catching section)
for sucking and catching the lower yarn Y2 from the yarn supplying
bobbin 8 and guiding the lower yarn Y2 to the yarn joining device
19 are arranged above and below the yarn joining device 19. The upper
35 yarn catching and guiding pipe 60 is arranged vertically swingable
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with a shaft 60a as a center, and includes a mouth 60b at the distal
~ end thereof. The lower yarn catching and guiding pipe 61 is also
arranged vertically swingable with a shaft 61a as center, and includes
a suction port 61b at the distal end thereof. Furthermore, an
5 appropriate negative pressure source is connected to the upper yarn
catching and guiding pipe 60 and the lower yarn catching and guiding
pipe 61, where air is sucked with the mouth 60b and the suction port
61b at the respective distal end to catch the yarn end.
The upper yarn catching and guiding pipe 60 is swung to the lower
10 side after catching the yarn end of the upper yarn Y1 wound around
the surface of the package P with the mouth 6Gb to guide the caught
upper yarn Y1 to the yarn joining device 19. Similarly, the lower
yarn catching and guiding pipe 61 is also swung to the upper side
after sucking and catching the yarn end of the lower yarn Y2 of the
15 yarn supplying bobbin 8 with the suction port 61b to guide the caught
lower yarn Y2 to the yarn joining device 19.
Also in the winding unit lA, when the yarn is all unwound from
the yarn supplying bobbin 8, the yarn end may get entangled with the
package P or may bite into the yarn layer of the package P.
20 Alternatively, the yarn end may be flipped to a position displaced
from the position where the mouth 6Gb sucks and catches the yarn end.
In such cases, the yarn end becomes difficult to be caught by the
mouth 60b. Therefore, in such a winding unit 1A as well, it is very
effective to apply the present invention and decelerate the winding
25 speed of the package forming device 4 prior to the end of unwinding
of the yarn of the yarn supplying bobbin 8 in terms of enabling the
yarn end to be easily caught and increasing the success rate of the
yarn joining operation. Irt the present embodiment, the package
forming device 4 is the winding section adapted to wind the yarn
30 unwound from the yarn supplying bobbin 8.
In the above embodiment, two photosensors 55a, 55b are
illustrated as the yarn amount detecting section 12 of the winding
unit 1, lA, but the present invention is not limited thereto. An
unwinding length detecting sensor for detecting the length of the
35 yarn from the behavior of the yarn unwound from the yarn supplying
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bobbin 8 may be adopted for the yarn amount detecting section 12.
Therefore, the remaining yarn amount, which is the amount of
yarn left on the yarn supplying bobbin, can be calculated by detecting
the length of the yarn unwound from the yarn supplying bobbin by the
5 unwinding length detecting sensor for detecting the length of the
yarn. Thus, the state immediately before the end of the unwinding
of the yarn in which the yarn amount becomes small is prevented from
being overlooked.
In the yarn winding device of the present invention, the control
10 section decelerates the winding speed of the winding section when
t.h.. e yarn amount detecting section detects that the amount of yarn
of the yarn supplying bobbin is less than a predetermined amount.
Thus, when the amount of yarn of the yarn supplying bobbin
becomes the predetermined amount, the winding speed of the winding
15 section is decelerated assuming the end of unwinding of the yarn is
close, whereby the deceleration is carried out prior to the end of
unwinding of the yarn.
In the yarn winding device of the present invention, the yarn
amount detecting section includes a plurality of sensors each adapted
20 to detect presence or absence of yarn at a plurality of positions
in an axial direction of the yarn supplying bobbin.
By thus detecting the amount of yarn of the yarn supplying bobbin
by the plurality of sensors, a state immediately before the end of
unwinding of the yarn in which the yarn amount is small is prevented
25 from being overlooked.
In the yarn winding device of the present invention, the control
section determines that the amount of yarn of the yarn supplying bobbin
is less than the predetermined amount when at least one of the
plurality sensors detects that the yarn is absent at the detecting
30 position.
In the state immediately before the end of unwinding, the yarn
unwound last may concentrate and may be left as a lump in one area
of the yarn supplying bobbin. In such a case, when the remaining yarn
is unwound from the state in which the lump of remaining yarn is
35 detected with the sensor, a state in which the yarn of the yarn
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supplying bobbin becomes completely absent is immediately reached.
Hence, it is too late to decelerate the winding section thereafter.
In the present invention, when at least one of the plurality
of sensors detects that the yarn is absent at the detecting position,
the control section determines the yarn of the yarn supplying bobbin
is less than the predetermined amount. In other words, even when the
lump portion of remaining yarn exists and a certain sensor detects
the lump of the remaining yarn, determination is made that the yarn
of the yarn supplying bobbin is less than the predetermined amount
when the yarn is absent at the detecting position of another sensor.
Thus, the state before the end of unwinding of the yarn can be detected
at an early stage.
The yarn amount detecting section of the yarn winding device
of the present invention is an unwinding length detection sensor
adapted to detect a length of the yarn unwound from the yarn supplying
bobbin.
Thus, the remaining yarn amount of the yarn supplying bobbin
is calculated by the unwinding length detection sensor that detects
the length of the unwound yarn. The state immediately before the end
of the unwinding of the yarn in which the yarn amount is small is
thus prevented from being overlooked.
The yarn winding device of the present invention includes a yarn
state detecting section arranged in a yarn travelling path between
the bobbin supporting section and the winding section, and adapted
to detect a state of a travelling yarn, wherein the control section
decelerates the winding speed of the winding section, and then stops
the winding operation of the winding section when the yarn state
detecting section no longer detects the yarn.
According to the present invention, whether or not the yarn is
travelling is detected by the yarn state detecting section arranged
between the bobbin supporting section and the winding section and
adapted to detect the state of the yarn. According to such a
configuration, the end of unwinding of the yarn of the yarn supplying
bobbin can be reliably grasped.
In the present invention, the yarn state detecting section may
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be a yarn defect detecting device adapted to detect a yarn defect
contained in the yarn. Alternatively, the yarn state detecting
section may be a yarn presence/absence detecting device adapted to
detect presence or absence of the yarn travelling through the yarn
travelling path. Alternatively, the yarn state detecting section may
be a yarn speed detecting device adapted to detect a speed of the
yarn travelling through the yarn travelling path. Alternatively, the
yarn state detecting section may be a yarn length detecting device
adapted to detect a length of the yarn travelling through the yarn
travelling path. Al ternatively, the yarn state detecting section may
be a yarn tension detecting device adapted to detect a tension of
the yarn travelling through the yarn travelling path.
According to the present invention, in the yarn winding
operation by the normal winding section, the end of unwinding of the
yarn of the yarn supplying bobbin is detected using various detecting
devices for detecting the state of the yarn. A dedicated detecting
section for detecting the end of unwinding of the yarn is not
necessary.
In the yarn winding device of the present invention, the yarn
amount detecting section also serves as the yarn state detecting
section adapted to detect a state in which the unwinding of the yarn
is finished and the yarn is not left on the yarn supplying bobbin
in addition to detecting whether or not the yarn of the yarn supplying
bobbin is less than the predetermined amount, wherein the control
section decelerates the winding speed of the winding section, and
then stops the winding operation of the winding section when the state
in which the yarn is not left on the yarn supplying bobbin is detected
by the yarn amount detecting section.
According to the present invention, the yarn amount detecting
section detects that the yarn of the yarn supplying bobbin is less
than the predetermined amount, and also detects the state of end of
the unwinding of the yarn. Therefore, the start of deceleration and
the stopping of winding of the winding section can be carried out
based on the detection result by one yarn amount detecting section.
A special detecting section for detecting the end of unwinding of
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the yarn is not necessary.
The yarn winding device of the present invention includes a
first yarn end catching section adapted to catch a yarn end from the
winding section in replacing the yarn supplying bobbin; a second yarn
end catching section adapted to catch a yarn end from the yarn
supplying bobbin in replacing the yarn supplying bobbin; and a yarn
joining device adapted to join the yarn end from the winding section
and the yarn end from the yarn supplying bobbin respectively caught
by the first yarn end catching section and the second yarn end catching
section.
As described above, by decelerating the winding speed of the
winding section prior to the end of unwinding of the yarn of the yarn
supplying bobbin, the yarn end (yarn end from the winding section)
is prevented from being entangled with the winding section when the
unwinding of the yarn is finished. Alternatively, the yarn end is
prevented from biting into the yarn layer of the winding section or
from being flipped to an area distant from a predetermined catching
position. Therefore, the yarn end of the winding section can be easily
caught by the first yarn end catching section, and the success
percentage of the yarn joining operation by the yarn joining device
increases.
The yarn winding device of the present invention further
includes a package forming device adapted to wind the yarn of the
yarn supplying bobbin around a winding tube to form a package, wherein
the winding section is a yarn accumulating device arranged between
the bobbin supporting section and the package forming device, and
adapted to wind the yarn unwound from the yarn supplying bobbin to
temporarily accumulate the yarn, and the package forming device winds
the yarn unwound from the yarn accumulating device around the winding
tube.
The yarn accumulating device is arranged between the bobbin
supporting section and the package forming device to temporarily
accumulate the yarn unwound from the yarn supplying bobbin. Even
under a state where the yarn is not supplied from the yarn supplying
bobbin such as at the time of replacing the yarn supplying bobbin
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or at the time of occurrence of yarn breakage, the yarn accumulated
in the yarn accumulating device can be supplied to the package forming
device. Accordingly, the interruption of the winding operation of
the package forming device can be suppressed as much as possible,
thus improving the package production efficiency. In the yarn
winding device equipped with such a yarn accumulating device, by
decelerating the winding speed of the yarn accumulating device prior
to the end of unwinding of the yarn of the yarn supplying bobbin when
the amount of yarn of the yarn supplying bobbin becomes small, the
yarn end from the yarn accumulating device can be easily caught after
the end of unwinding of the yarn. Furthermore, the yarn winding device
can promptly resume the winding (accumulation of yarn) after replacing
the yarn supplying bobbin.
In the yarn winding device of the present invention, the control
section decelerates a winding speed of the package forming device
when decelerating the winding speed of the winding section prior to
the end of unwinding of the yarn of the yarn supplying bobbin.
In the present invention, the winding speed of the package
forming device is decelerated when decelerating the winding speed
of the winding section prior to the end of unwinding of the yarn of
the yarn supplying bobbin. Thus, it is possible to avoid sudden
reduction in the yarn amount accumulated in the yarn accumulating
device. According to such a configuration, the yarn accumulated in
the yarn accumulating device is prevented from running out.
The winding section of the yarn winding device of the present
invention is a package forming device adapted to wind the yarn of
the yarn supplying bobbin around a winding tube to form a package,
and the package forming device unwinds the yarn from the yarn supplying
bobbin to wind the yarn around the winding tube.
Accordingly, the yarn end of the package can be easily caught
by the first yarn end catching section, and the success percentage
of the yarn joining operation by the yarn joining device increases.
The package production efficiency is thus improved.
A yarn winding method of the present invention is a method for
winding a yarn unwound from a yarn supplying bobbin, the method
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including a step of detecting an amount of yarn left on the yarn
supplying bobbin, and a step of predicting end of unwinding of the
yarn of the yarn supplying bobbin from a detection result of the yarn
amount detecting step, and decelerating a winding speed of a winding
section adapted to wind the yarn prior to the end of unwinding of
the yarn of the yarn supplying bobbin.
According to the present invention, the remaining amount of the
yarn of the yarn supplying bobbin is detected to predict the end of
unwinding of the yarn, and the winding speed of the winding section
is decelerated prior to the end of unwinding of the yarn to stop the
winding before the yarn end reaches the winding section. Even if the
yarn end is wound by the winding section, since the tension of the
yarn is lowered by the deceleration before the end of unwinding of
the yarn, the yarn end is less likely to bite into the yarn layer
of the winding section and the yarn end is neither flipped. Therefore,
the yarn end of the yarn unwound from the yarn supplying bobbin becomes
easy to catch.
The yarn winding method of the present invention further
includes a step of stopping the winding section before the yarn end
of when the yarn of the yarn supplying bobbin is all unwound reaches
the winding section after the winding speed of the winding section
is decelerated in the decelerating step.
The yarn end is more easily caught by stopping the winding
operation of the winding section before the yarn end of the yarn of
the yarn supplying bobbin reaches the winding section.
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WE CLAIM:
1. A yarn winding device characterized by comprising:
a bobbin supporting section adapted to support a yarn supplying
bobbin;
a winding section adapted to wind a yarn unwound from the yarn
supplying bobbin ;
a yarn amount detecting section adapted to detect an amount of
yarn of the yarn supplying bobbin ;
a control section adapted to control a winding speed of the
winding section ; and
a yarn state detecting section adapted to detect a state of a
travelling yarn, characterized in that
the control section is adapted to predict an end of unwinding
of the yarn of the yarn supplying bobbin based on a detection result
of the yarn amount detecting section , and to decelerate the winding
speed of the winding section to stop the winding operation of the
winding section before a yarn end reaches the winding section based
on the detection result of the yarn state detecting section after
the end of unwinding of the yarn from the yarn supplying bobbin.
2. The yarn winding device according to claim 1, wherein the
control section is adapted to decelerate the winding speed of the
winding section when the yarn amount detecting section detects that
the amount of yarn of the yarn supplying bobbin is less than a
25 predetermined amount.
3. The yarn winding device according to claim 2, wherein the
yarn amount detecting section includes a plurality of sensors each
adapted to detect presence or absence of yarn at a plurality of
30 positions in an axial direction of the yarn supplying bobbin.
4. The yarn winding device according to claim 3, wherein the
control section is adapted to determine that the amount of yarn of
the yarn supplying bobbin is less than the predetermined amount when
35 at least one of the plurality of sensors detects that the yarn is
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absent at its detecting position.
5. The yarn winding device according to claim 2, wherein the
yarn amount detecting section is an unwinding length detecting sensor
adapted to detect a length of the yarn unwound from the yarn supplying
bobbin.
6. The yarn winding device according to anyone of claims 1
to 5, wherein
the yarn state detecting section is arranged in a yarn
travelling path between the bobbin supporting section and the winding
section , and
the control section is adapted to decelerate the winding speed
of the winding section and then to stop the winding operation of the
winding section when the yarn state detecting section no longer
detects the yarn.
7. The yarn winding device according to claim 6, wherein the
yarn state detecting section is a yarn defect detecting device adapted
'to detect a yarn defect contained in the yarn.
8. The yarn winding device according to claim 6, wherein the
yarn state detecting section is a yarn presence/absence detecting
device adapted to detect presence or absence of the yarn travelling
through the yarn travelling path.
9. The yarn winding device according to claim 6, wherein the
yarn state detecting section is a yarn speed detecting device adapted
to detect a speed of the yarn travelling through the yarn travelling
path.
'10. The yarn winding device according to claim 6, wherein the
yarn state detecting section is a yarn length detecting device adapted
to detect a length of the yarn travelling through the yarn travelling
path.
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11. The yarn winding device according to claim 6, wherein the
yarn state detecting section is a yarn tension detecting device
adapted to detect a tension of the yarn travelling through the yarn
5 travelling path.
12. The yarn winding device according to anyone of claims 1
to 5, wherein
the yarn amount detecting section also serves as the yarn state
10 detecting section adapted to detect a state in which the unwinding
of the yarn is finished and the yarn is not left on the yarn supplying
bobbin in addition to detecting whether or not the yarn of the yarn
supplying bobbin is less than the predetermined amount, and
the control section is adapted to decelerate the winding speed
15 of the winding section , and then to stop the winding operation of
the winding section when a state in which no yarn is left on the yarn
supplying bobbin is detected by the yarn amount detecting section.
13. The yarn winding device according to anyone of claims 1
20 to 12, characterized by further comprising:
a first yarn end catching section adapted to catch a yarn end
from the winding section after replacing the yarn supplying bobbin;
a second yarn end catching section adapted to catch a yarn end
from the yarn supplying bobbin in replacing the yarn supplying bobbin;
25 and
a yarn joining device adapted to join the yarn end from the
winding section and the yarn end from the yarn supplying bobbin
respectively caught by the first yarn end catching section and the
second yarn end catching section.
30
14. The yarn winding device according to anyone of claims 1
to 13, characterized by further comprising
a package forming device adapted to wind the yarn of the yarn
supplying bobbin around a winding tube to form a package, wherein
35 the winding section is a yarn accumulating device arranged
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5
10
15
20
25
30
35
between the bobbin supporting section and the package forming device
and adapted to wind the yarn unwound from the yarn supplying bobbin
to temporarily accumulate the yarn, and
the package forming device winds the yarn unwound from the yarn
accumulating device around the winding tube.
15. The yarn winding device according to claim 14, wherein the
control section is adapted to decelerate a winding speed of the package
forming device when decelerating the winding speed of the winding
section prior to the end of unwinding of the yarn of the yarn supplying
bobbin.
16. The yarn winding device according to anyone of claims 1
to 13, wherein the winding section is a package forming device adapted
to wind the yarn of the yarn supplying bobbin around a winding tube
to form a package, and the package forming device is adapted to unwind
the yarn from the yarn supplying bobbin to wind the yarn around the
winding tube.
17. A yarn winding method for winding a yarn unwound from a
yarn supplying bobbin, the method characterized by comprising:
a step of detecting a yarn amount left on the yarn supplying
bobbin; and
a step of predicting end of unwinding of the yarn of the yarn
supplying bobbin from a detection result of the yarn amount detecting
step, and decelerating a winding speed of a winding section adapted
to wind the yarn prior to the end of unwinding of the yarn of the
yarn supplying bobbin.
18. The yarn winding method according to claim 17,
characterized by further comprising
a step of stopping the winding section before the yarn end when
the yarn of the yarn supplying bobbin is all unwound reaches the
winding section after the winding speed of the winding section is
decelerated in the decelerating step.
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19. The yarn winding device, substantially as herein
described with reference to accompanying drawings and examples.
20. The yarn winding method, substantially as herein
5 described with reference to accompanying drawings and examples.
10
Dated this 29th day of April 2013
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Of Anand and Anand Advocates
Agent for the Applicant