BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] 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
[0002] 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.
[0003] An automatic winder of Japanese Unexamined Patent Publication 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 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 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.
[0004] As disclosed in Japanese Unexamined Patent Publication No.
2009-242042, there is known an automatic winder including a yarn 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 device and the yarn end from the yarn supplying
bobbin are respectively caught with a yarn end catching member and transported to
the yarn 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. 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 pull out the yarn end pulled into the yarn
accumulating device. In the automatic winder of Japanese Unexamined Patent Publication
No.
2009-242042, since the 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.
[0005] When the yarn of the yarn supplying bobbin is all unwound, a 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 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 position where the yarn end catching
member sucks and catches the yarn end. In such cases, the yarn end becomes difficult
to catch.
[0006] 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.
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 difficult to
pull out by the pull-out mechanism, and the yarn end 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
[0007] An object of the present invention is to improve catching probability of a yarn end
unwound from a previous yarn supplying bobbin at the time of replacing the yarn supplying
bobbin.
[0008] 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 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 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.
[0009] 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 is finished.
Therefore, the yarn end of the yarn unwound from the yarn supplying bobbin becomes
easy to catch.
[0010] In the yarn winding device of the present invention, the control section decelerates
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 predetermined
amount.
[0011] Thus, when the amount of yarn of the yarn supplying bobbin becomes the predetermined
amount, the winding speed of the winding 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.
[0012] In the yarn winding device of the present invention, the yarn amount detecting section
includes a plurality of sensors each adapted to detect presence or absence of yarn
at a plurality of positions in an axial direction of the yarn supplying bobbin.
[0013] 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 from being overlooked.
[0014] 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 position.
[0015] 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 detected with the sensor, a state in which the yarn of the yarn supplying bobbin
becomes completely absent is immediately reached. Hence, it is too late to decelerate
the winding section thereafter.
[0016] 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.
[0017] 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.
[0018] 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.
[0019] 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.
[0020] 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.
[0021] In the present invention, the yarn state detecting section may 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.
Alternatively, 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.
[0022] 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.
[0023] 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.
[0024] 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 the yarn is not necessary.
[0025] 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.
[0026] 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.
[0027] 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.
[0028] 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 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.
[0029] 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.
[0030] 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.
[0031] 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.
[0032] 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.
[0033] A yarn winding method of the present invention is a method for winding a yarn unwound
from a yarn supplying bobbin, the method 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.
[0034] 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.
[0035] 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.
[0036] 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.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] FIG. 1 is a side view of one winding unit of an automatic winder according to the
present invention;
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
[0038] 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 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.
[0039] As illustrated in FIG. 1, each winding unit (yarn winding device) 1 includes a bobbin
supplying device 2, a bobbin supporting 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 tube 6 while traversing the spun yarn
Y to form a package P of a predetermined shape.
[0040] 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 bobbin 8 out of the plurality of yarn supplying bobbins
held in the magazine 10 is dropped diagonally so that the yarn supplying bobbin 8
is supplied to the bobbin supporting section 3.
[0041] 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.
[0042] 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.
[0043] 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.
[0044] 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.
[0045] 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 teeth and movable comb teeth movably arranged with respect
to the fixed comb teeth.
[0046] 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 Y1 from the yarn accumulating device 22 guided by a guide member 32,
to be described later.
[0047] 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.
[0048] The yarn joining device 19 joins the lower yarn Y2 from the yarn supplying bobbin
8 and the upper yarn Y1 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 Y1 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.
[0049] 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.
[0050] 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 (yarn travelling path side).
[0051] 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 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 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 20 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 in this manner, the yarn joining device 19 joins
the upper yarn Y1 and the lower yarn Y2.
[0052] 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 yarn accumulating device 22 will be described later.
[0053] 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 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
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 the yarn
may be adopted for the package forming device 4. When the 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.
[0054] In the present embodiment, the yarn accumulating device 22 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 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.
[0055] The unit control section 5 (control section) is configured by a CPU (Central Processing
Unit) which is an arithmetic processing 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 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.
[0056] Next, the yarn accumulating device 22 will be described in detail. FIG. 2 is a side
view of the yarn accumulating device 22. 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 accumulating roller 40 at the time of the yarn
joining operation.
[0057] 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, as a center. Tapered portions 40a, 40b, with
a diameter, which becomes larger towards the end, are formed at both axial ends 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.
[0058] 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.
[0059] 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.
[0060] 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 is 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.
[0061] 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 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.
[0062] A rubber annular member 45 such as a rubber band, an O 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.
[0063] 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.
[0064] 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 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.
[0065] 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 Y1 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 Y1 is led to the yarn joining device 19.
[0066] The upper yarn Y1 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 Y1 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 Y1 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 upper yarn catching
device 18 becomes difficult.
[0067] The winding unit 1 of the present embodiment is thus devised to easily catch the
yarn end of the upper yarn Y1 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 Y1 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.
[0068] 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.
[0069] 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 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.
[0070] 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.
[0071] 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.
[0072] 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 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.
[0073] 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.
[0074] In the present embodiment, 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.
[0075] 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 that
there is no yarn.
[0076] 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.
[0077] 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 (S11: decelerating step).
This decelerating state is maintained until the yarn left on the yarn supplying bobbin
8 is all unwound.
[0078] 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 unit 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 bobbin 8, and thus a dedicated detecting section for detecting
the end of unwinding of the yarn becomes unnecessary.
[0079] When the clearer 21 detects that the travelling yarn has run out (S12: Yes), the
unit control section 5 stops the rotation of the yarn accumulating roller 40 (S13:
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.
[0080] 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 (S15). 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.
[0081] Furthermore, in the control described above, the deceleration control of the yarn
accumulating roller 40 in S11 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
S11, 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 accumulating roller 40
can be stopped before the yarn travels the 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 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.
[0082] When decelerating the winding speed of the yarn accumulating roller 40 in S11, 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 prevented from running out.
[0083] 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
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 substantially
upright position.
[0084] 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 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 catching device 18 so that the upper yarn Y1 is guided to the yarn
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 (S16).
[0085] 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.
[0086] (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.
[0087] 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 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 D). 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).
[0088] 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
D), 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.
[0089] 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.
[0090] 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.
[0091] 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 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.
[0092] 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.
[0093] 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. 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 result of one yarn amount detecting section
12, a special detecting section for detecting the end of unwinding of the yarn is
not necessary.
[0094] 2) The above embodiment is an example in which the present invention is applied to
the winding unit 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, 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.
[0095] FIG. 6 illustrates a side view of the winding unit described above. As illustrated
in FIG. 6, in a winding unit 1A, the unwinding 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 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.
[0096] 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 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 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 yarn catching and guiding pipe
60 is arranged vertically swingable 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 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.
[0097] The upper yarn catching and guiding pipe 60 is swung to the lower side after catching
the yarn end of the upper yarn Y1 wound around the surface of the package P with the
mouth 60b 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 yarn supplying bobbin
8 with the suction port 61b to guide the caught lower yarn Y2 to the yarn joining
device 19.
[0098] Also in the winding unit 1A, 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. Alternatively, the yarn end may be flipped to a position displaced
from the position where the mouth 60b 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 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. In the present
embodiment, the package forming device 4 is the winding section adapted to wind the
yarn unwound from the yarn supplying bobbin 8.
[0099] In the above embodiment, two photosensors 55a, 55b are illustrated as the yarn amount
detecting section 12 of the winding unit 1, 1A, but the present invention is not limited
thereto. An unwinding length detecting sensor for detecting the length of the yarn
from the behavior of the yarn unwound from the yarn supplying bobbin 8 may be adopted
for the yarn amount detecting section 12.
[0100] 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 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.
1. A yarn winding device (1)
characterized by comprising:
a bobbin supporting section (3) adapted to support a yarn supplying bobbin (8);
a winding section (4, 22) adapted to wind a yarn (y) unwound from the yarn supplying
bobbin (8);
a yarn amount detecting section (12) adapted to detect an amount of yarn of the yarn
supplying bobbin (8);
a control section (5) adapted to control a winding speed of the winding section (4,
22); and
a yarn state detecting section (21) adapted to detect a state of a travelling yarn,
wherein
the control section (5) is adapted to predict an end of unwinding of the yarn (y)
of the yarn supplying bobbin (8) based on a detection result of the yarn amount detecting
section (12), and to decelerate the winding speed of the winding section (4, 22) to
stop the winding operation of the winding section before a yarn end reaches the winding
section (4, 22) based on the detection result of the yarn state detecting section
(21) after the end of unwinding of the yarn (y) from the yarn supplying bobbin (8).
2. The yarn winding device (1) according to claim 1, characterized in that the control section (5) is adapted to decelerate the winding speed of the winding
section (4, 22) when the yarn amount detecting section (12) detects that the amount
of yarn of the yarn supplying bobbin (8) is less than a predetermined amount.
3. The yarn winding device (1) according to claim 2, characterized in that the yarn amount detecting section (12) includes a plurality of sensors (55a, 55b)
each adapted to detect presence or absence of yarn at a plurality of positions in
an axial direction of the yarn supplying bobbin (8).
4. The yarn winding device (1) according to claim 3, characterized in that the control section (5) is adapted to determine that the amount of yarn of the yarn
supplying bobbin (8) is less than the predetermined amount when at least one of the
plurality of sensors (55a, 55b) detects that the yarn is absent at its detecting position.
5. The yarn winding device (1) according to claim 2, characterized in that the yarn amount detecting section (12) is an unwinding length detecting sensor adapted
to detect a length of the yarn unwound from the yarn supplying bobbin (8).
6. The yarn winding device (1) according to any one of claims 1 to 5, characterized in that
the yarn state detecting section (21) is arranged in a yarn travelling path between
the bobbin supporting section (3) and the winding section (4, 22), and
the control section (5) is adapted to decelerate the winding speed of the winding
section (4, 22) and then to stop the winding operation of the winding section (4,
22) when the yarn state detecting section (21) no longer detects the yarn.
7. The yarn winding device (1) according to claim 6, characterized in that the yarn state detecting section (21) is a yarn defect detecting device (21) adapted
to detect a yarn defect contained in the yarn.
8. The yarn winding device (1) according to claim 6, characterized in that the yarn state detecting section (21) 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 (1) according to claim 6, characterized in that the yarn state detecting section (21) 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 (1) according to claim 6, characterized in that the yarn state detecting section (21) is a yarn length detecting device adapted to
detect a length of the yarn travelling through the yarn travelling path.
11. The yarn winding device (1) according to claim 6, characterized in that the yarn state detecting section (21) is a yarn tension detecting device adapted
to detect a tension of the yarn travelling through the yarn travelling path.
12. The yarn winding device (1) according to any one of claims 1 to 5, characterized in that
the yarn amount detecting section (12) also serves as the yarn state detecting section
(21) 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 (8) in addition to detecting whether
or not the yarn of the yarn supplying bobbin (8) is less than the predetermined amount,
and
the control section (5) is adapted to decelerate the winding speed of the winding
section (4, 22), and then to stop the winding operation of the winding section (4,
22) when a state in which no yarn is left on the yarn supplying bobbin (8) is detected
by the yarn amount detecting section (12).
13. The yarn winding device (1) according to any one of claims 1 to 12,
characterized by further comprising:
a first yarn end catching section (60) adapted to catch a yarn end from the winding
section (4, 22) after replacing the yarn supplying bobbin (8);
a second yarn end catching section (61) adapted to catch a yarn end from the yarn
supplying bobbin (8) in replacing the yarn supplying bobbin (8); and
a yarn joining device (19) adapted to join the yarn end from the winding section (4,
22) and the yarn end from the yarn supplying bobbin (8) respectively caught by the
first yarn end catching section (60) and the second yarn end catching section (61).
14. The yarn winding device (1) according to any one of claims 1 to 13, characterized by further comprising
a package forming device (4) adapted to wind the yarn (y) of the yarn supplying bobbin
(8) around a winding tube (6) to form a package (P), wherein
the winding section is a yarn accumulating device (22) arranged between the bobbin
supporting section (3) and the package forming device (4) and adapted to wind the
yarn (y) unwound from the yarn supplying bobbin (8) to temporarily accumulate the
yarn (y), and
the package forming device (4) winds the yarn (y) unwound from the yarn accumulating
device (22) around the winding tube (6).
15. The yarn winding device (1) according to claim 14, characterized in that the control section (5) is adapted to decelerate a winding speed of the package forming
device (4) when decelerating the winding speed of the winding section (4, 22) prior
to the end of unwinding of the yarn (y) of the yarn supplying bobbin (8).
16. The yarn winding device (1) according to any one of claims 1 to 13, characterized in that the winding section is a package forming device (4) adapted to wind the yarn of the
yarn supplying bobbin (8) around a winding tube (6) to form a package (P), and the
package forming device (4) is adapted to unwind the yarn (y) from the yarn supplying
bobbin (8) to wind the yarn (y) around the winding tube (6).
17. A yarn winding method for winding a yarn (y) unwound from a yarn supplying bobbin
(8), the method
characterized by comprising:
a step of detecting a yarn amount left on the yarn supplying bobbin (8); and
a step of predicting end of unwinding of the yarn of the yarn supplying bobbin (8)
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 (8).
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 (y) of the
yarn supplying bobbin (8) is all unwound reaches the winding section after the winding
speed of the winding section is decelerated in the decelerating step.