Field of the Invention
5 [0001] The present invention relates to a yarn winding device
and an automatic winder.
2. Description of the Related Art
[0002] For example, JP 2010-269915 A discloses a yarn winding
10 device configured to wind a yarn around a package while traversing
the yarn by rotating a traverse drum that is in contact with a
peripheral surface of the package.
[0003] In such a yarn winding device, for example, when the
yarn is joined while traveling on a back side of the traverse drum,
15 the yarn may not be traversed properly and cause straight winding.
“Straight winding” means that the yarn is not traversed normally
and the yarn is intensively wound on a part of a traverse area.
The package formed with the straight winding is to be a defective
product. Therefore, when the straight winding has occurred, it is
20 desirable to detect the fact as soon as possible and to take
appropriate measures.
[0004] The yarn winding device disclosed in JP 2010-269915 A
is configured to detect a rotation failure of a package, but does
not disclose any configuration for detecting straight winding.
25 Some yarn winding devices are provided with a traverse sensor that
detects that a yarn is being traversed, and a yarn speed sensor
(yarn length sensor) that detects a travelling speed of a yarn.
Such sensors enable detection of an occurrence of straight winding.
However, a yarn winding device not provided with such sensors has
30 been unable to detect an occurrence of the straight winding.
BRIEF SUMMARY OF THE INVENTION
[0005] The present invention has been made in view of the
above problems, and an object thereof is to enable detection of an
35 occurrence of straight winding even without a traverse sensor or
3
a yarn speed sensor being provided.
[0006] A yarn winding device according to the present
invention is a yarn winding device configured to wind a yarn around
a package by traversing the yarn while rotating a drum that is in
5 contact with a peripheral surface of the package. The yarn winding
device includes a control section that determines whether or not
straight winding has occurred in which the yarn is intensively
wound around a part of a traverse area, based on a package wind
number indicating how many rotations the package makes while the
10 yarn is traversed for a unit number of times.
[0007] According to such a yarn winding device, it is possible
to detect an occurrence of straight winding as long as the package
wind number is obtained. The package wind number can be calculated
from a number of rotations of the package and a number of rotations
15 of the drum, and a sensor for detection of these numbers of
rotations is generally provided on the yarn winding device.
Therefore, an occurrence of straight winding can be detected even
when no traverse sensor or yarn speed sensor is provided.
[0008] In the present invention, the control section desirably
20 determines whether or not straight winding has occurred, based on
a decrease amount (change amount) of the package wind number in a
predetermined time.
[0009] As will be described later in detail, when straight
winding occurs, the package wind number changes rapidly. Therefore,
25 by using a decrease amount in the package wind number as a
determination criterion of an occurrence of straight winding, it
is possible to appropriately determine whether or not straight
winding has occurred.
[0010] In the present invention, the control section desirably
30 determines that straight winding has occurred when a decrease
amount in the package wind number during the predetermined time
exceeds a predetermined first threshold value.
[0011] As will be described later in detail, according to this
configuration, when straight winding occurs on a large-diameter
35 side of a cone-wound package, the occurrence of the straight
4
winding can be detected satisfactorily.
[0012] In the present invention, the control section desirably
determines that straight winding has occurred when a decrease
amount in the package wind number during the predetermined time
5 falls below a predetermined second threshold value.
[0013] As will be described later in detail, according to this
configuration, when straight winding occurs on a small-diameter
side of the cone-wound package, the occurrence of the straight
winding can be detected satisfactorily.
10 [0014] In the present invention, there is desirably provided
an alarm section that notifies, when the control section determines
that straight winding has occurred, an operator of the fact.
[0015] Providing such an alarm section allows the operator to
immediately recognize an occurrence of straight winding, making it
15 possible to quickly respond to the occurrence of the straight
winding.
[0016] In the present invention, when the control section
determines that the straight winding has occurred, the control
section desirably controls to stop winding of the yarn around the
20 package.
[0017] This configuration can minimize an amount of the yarn
wound around the package in a straight winding state.
[0018] In the present invention, the yarn is desirably wound
around the cone-wound package whose winding diameter gradually
25 increases or decreases in an axial direction.
[0019] As will be described later in detail, when the package
is the cone-wound package, an occurrence of straight winding can
be accurately detected because the number of rotations of the
package changes particularly rapidly when straight winding occurs.
30 [0020] In the present invention, the drum is desirably a
traverse drum formed with a traverse groove for traverse of the
yarn on a peripheral surface.
[0021] The wind number of the traverse drum depends on a type
of the drum and does not change during winding of the yarn.
35 Therefore, when the traverse drum is used, the package wind number
5
can be easily obtained.
[0022] An automatic winder according to the present invention
has a feature in which a plurality of any of the above-described
yarn winding devices are arranged.
5 [0023] According to such an automatic winder, an occurrence
of straight winding can be detected even when no traverse sensor
or yarn speed sensor is provided on each yarn winding device.
BRIEF DESCRIPTION OF THE DRAWINGS
10 [0024] FIG. 1 is a schematic configuration view of an
automatic winder according to the present embodiment;
FIG. 2 is a front view of a winding unit;
FIGS. 3(a) and 3(b) are schematic side views illustrating a
wound state of a yarn;
15 FIG. 4 is a graph illustrating transition of a package wind
number during normal winding;
FIG. 5 is a graph illustrating transition of a decrease
amount in a package wind number during normal winding;
FIGS. 6(a) to 6(c) are schematic front views illustrating a
20 wound state of a yarn;
FIGS. 7(a) and 7(b) are graphs illustrating transition of a
decrease amount in a package wind number when straight winding
occurs; and
FIGS. 8(a) and 8(b) are graphs illustrating transition of a
25 decrease amount in a package wind number, and threshold values.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0025] Hereinafter, an example of an embodiment of the present
invention will be described with reference to the drawings.
30 [0026] (Automatic winder)
FIG. 1 is a schematic configuration view of an automatic
winder according to the present embodiment. As illustrated in FIG.
1, an automatic winder 1 includes: a plurality of winding units 2
(corresponding to a yarn winding device of the present invention)
35 arranged in one direction; a doffing device 3 provided along an
6
arrangement direction of the plurality of winding units 2 to be
capable of travelling; and a machine control device 4. Hereinafter,
as illustrated in FIG. 1, the arrangement direction of the
plurality of winding units 2 is referred to as a lateral direction,
5 and a direction orthogonal to both the lateral direction and a
vertical direction (a direction perpendicular to the page of FIG.
1) is referred to as a longitudinal direction. Regarding the
longitudinal direction, a description will be given with a near
side in a direction perpendicular to the page of FIG. 1 is a front
10 side, while a depth side is a back side.
[0027] The automatic winder 1 forms a package P by winding a
yarn Y unwound from a yarn supplying bobbin B in each of the
winding units 2. When the package P is completed in a certain
winding unit 2, the doffing device 3 moves to the winding unit 2,
15 collects the completed package P, and replaces it with an empty
winding tube. The machine control device 4 controls the entire
automatic winder 1 and issues control signal to each of the winding
units 2 and the doffing device 3.
[0028] (Winding unit)
20 FIG. 2 is a front view of the winding unit 2. The winding
unit 2 winds the yarn Y unwound from the yarn supplying bobbin B
around a winding tube Q while traversing, to form the package P.
The winding unit 2 includes: a yarn supplying section 10 that holds
the yarn Y of the yarn supplying bobbin B in a state capable of
25 being supplied; a yarn processing section 20 that performs various
processes on the yarn Y unwound from the yarn supplying bobbin B
held by the yarn supplying section 10; a winding section 30 that
winds the yarn Y processed by the yarn processing section 20 around
the winding tube Q to form the package P; and a unit control
30 section 40 (corresponding to a control section of the present
invention) that controls each sections 10, 20, and 30. The yarn
supplying section 10, the yarn processing section 20, and the
winding section 30 are arranged in this order from bottom to top.
[0029] The yarn supplying section 10 includes a bobbin holding
35 section 11 that holds the yarn supplying bobbin B, and an unwinding
7
assisting device 12 that assists in unwinding the yarn Y from the
yarn supplying bobbin B. The unwinding assisting device 12 has a
cylindrical body 13 that is placed over the yarn supplying bobbin
B from above. The cylindrical body 13 is configured to be lifted
5 and lowered by a lifting device (not illustrated). The unwinding
assisting device 12 lowers the cylindrical body 13 as the unwinding
of the yarn Y progresses, to regulate bulging (balloon) of the
yarn Y during unwinding and stabilize a tension of the yarn Y.
[0030] The winding section 30 includes a cradle 31 that
10 supports the package P (the winding tube Q), and a traverse drum
32 (corresponding to a drum of the present invention) that
traverses the yarn Y. The cradle 31 rotatably supports both end
parts of the package P. The traverse drum 32 is in contact with
a peripheral surface of the package P, and is rotationally driven
15 by a drum motor 33. A traverse groove 32a is formed on a peripheral
surface of the traverse drum 32, and the yarn Y is traversed by
the traverse drum 32 rotating while the yarn Y is positioned in
the traverse groove 32a. As the traverse drum 32 rotates while
being in contact with the package P, the package P is driven to
20 rotate, and the yarn Y being traversed by the traverse drum 32 is
wound around the package P.
[0031] The winding section 30 is further provided with a drum
rotation sensor 34 that detects a number of rotations of the
traverse drum 32, and a package rotation sensor 35 that detects a
25 number of rotations of the package P. The drum rotation sensor 34
and the package rotation sensor 35 include, for example, a
proximity sensor. Detection values by the drum rotation sensor 34
and the package rotation sensor 35 are transmitted to the unit
control section 40.
30 [0032] The yarn processing section 20 includes a tension
applying device 21, a yarn joining device 22, a yarn clearer 23,
a lower-yarn capturing and guiding member 24, and an upper-yarn
capturing and guiding member 25.
[0033] The tension applying device 21 applies a predetermined
35 tension on the travelling yarn Y. FIG. 2 illustrates a so-called
8
gate-type tension applying device 21 as an example. In the gatetype tension applying device 21, a plurality of fixed gate bodies
21a and a plurality of movable gate bodies 21b are alternately and
vertically arranged. Then, by adjusting a horizontal position of
5 the plurality of movable gate bodies 21b, a predetermined tension
is applied to the travelling yarn Y between the fixed gate body
21a and the movable gate body 21b.
[0034] When a yarn defect is detected by the yarn clearer 23
described later and the yarn Y is cut by a cutter 23a, when the
10 yarn Y breaks during winding, when the yarn Y of the yarn supplying
bobbin B runs out and the yarn supplying bobbin B is replaced, and
the like, the yarn joining device 22 joins the divided yarn Y
(lower yarn Y) on the yarn supplying bobbin B side (the yarn
supplying section 10 side) and yarn Y (upper yarn Y) on the package
15 P side (the winding section 30 side).
[0035] On a lower side and an upper side of the yarn joining
device 22, there are respectively provided the lower-yarn
capturing and guiding member 24 that captures and guides the lower
yarn Y to the yarn joining device 22, and the upper-yarn capturing
20 and guiding member 25 that captures and guides the upper yarn Y to
the yarn joining device 22. The lower-yarn capturing and guiding
member 24 is rotatable around a shaft 24a, and turns up and down
by being rotationally driven by a motor (not illustrated). The
lower-yarn capturing and guiding member 24 has, at a distal end
25 portion thereof, a suction section 24b that sucks and captures a
yarn end of the lower yarn Y. The upper-yarn capturing and guiding
member 25 is rotatable around a shaft 25a, and turns up and down
by being rotationally driven by a motor (not illustrated). The
upper-yarn capturing and guiding member 25 has, at a distal end
30 portion thereof, a suction section 25b that sucks and captures a
yarn end of the upper yarn Y.
[0036] When joining the yarn with the yarn joining device 22,
the lower-yarn capturing and guiding member 24 guides the lower
yarn Y to the yarn joining device 22, and the upper-yarn capturing
35 and guiding member 25 guides the upper yarn Y to the yarn joining
9
device 22. Specifically, after sucking and capturing a yarn end
of the lower yarn Y with the suction section 24b, the lower-yarn
capturing and guiding member 24 guides the lower yarn Y to the
yarn joining device 22 by turning upward. Further, by first
5 turning upward and positioning the suction section 25b near a
contact point between the package P and the traverse drum 32, the
upper-yarn capturing and guiding member 25 sucks and captures a
yarn end of the upper yarn Y attached to a surface of the package
P by the suction section 25b. Then, the upper-yarn capturing and
10 guiding member 25 turns downward from above, to guide the upper
yarn Y to the yarn joining device 22. The yarn joining device 22
connects the yarn end of the lower yarn Y guided by the lower-yarn
capturing and guiding member 24 and the yarn end of the upper yarn
Y guided by the upper-yarn capturing and guiding member 25, to
15 form one yarn Y.
[0037] The yarn clearer 23 constantly acquires information on
a thickness of the travelling yarn Y, and detects an abnormal
portion where a thickness of the yarn Y is larger than a certain
value as a yarn defect, based on the information on the thickness
20 of the travelling yarn Y. Further, the yarn clearer 23 is provided
with the cutter 23a, and the cutter 23a immediately cuts the yarn
Y when a yarn defect is detected by the yarn clearer 23. Then,
after removing of the yarn defect, the yarn joining device 22 joins
the yarn together.
25 [0038] The winding unit 2 is provided with an alarm section
41. The alarm section 41 is for notifying an operator that an
abnormality has occurred in the winding unit 2. The alarm section
41 of the present embodiment includes a lamp that informs of an
abnormality by blinking or lighting of light, and/or a speaker
30 that informs of an abnormality by sound, but the configuration of
the alarm section 41 is not limited to this.
[0039] (Occurrence of straight winding)
FIGS. 3A and 3B are schematic side views illustrating a wound
state of the yarn Y. FIG. 3A illustrates a state where the yarn
35 Y is normally wound, and FIG. 3B illustrates a state where the
10
yarn Y is subjected to straight winding. When the yarn Y is wound
normally, the yarn Y is wound around the package P while travelling
in the traverse groove 32a formed in the traverse drum 32 as
illustrated in FIG. 3A. Therefore, the yarn Y is appropriately
5 traversed by the traverse drum 32, and the package P having a
desired shape is formed.
[0040] However, for example, when the yarn is joined in a
state where the yarn Y hanging from the package P is traveling on
a back side (lower side) of the traverse drum 32, as illustrated
10 in FIG. 3B, the yarn Y does not travel in the traverse groove 32a,
and the yarn Y is not traversed. Then, “straight winding” occurs,
in which the yarn Y is intensively wound around a part of a traverse
area. The package P formed with the straight winding is a
defective product. Therefore, when the straight winding has
15 occurred, it is desirable to detect the fact as soon as possible
and to take appropriate measures. Therefore, in the present
embodiment, straight winding is detected by the following method.
[0041] (Detection of straight winding)
There is a parameter called a wind number for each of the
20 traverse drum 32 and the package P. The wind number indicates how
many rotations the traverse drum 32 and the package P make while
the yarn Y is traversed back and forth once, that is, while the
yarn Y is moved once from one end to the other end of the traverse
area. The wind number of the traverse drum 32 (hereinafter, a
25 drum wind number) is a constant value determined by a type of the
traverse drum 32, and does not change while the yarn Y is being
wound. Whereas, the wind number of the package P (hereinafter, a
package wind number) decreases as a diameter of the package P
increases.
30 [0042] FIG. 4 is a graph illustrating transition of a package
wind number during normal winding. FIG. 5 is a graph illustrating
transition of a decrease amount in the package wind number, which
is an indicator of a change amount in the package wind number
during normal winding. The “wind number decrease amount” in FIG.
35 5 indicates how much the package wind number has decreased in 10
11
seconds. When the yarn Y is wound normally, a diameter of the
package P increases with time, and the number of rotations of the
package P during one rotation of the traverse drum 32 decreases.
Therefore, as illustrated in FIG. 4, the package wind number
5 gradually decreases. As illustrated in FIG. 5, a decrease amount
in the package wind number gradually decreases (a decrease rate
slows down) over a long period of time while repeating a slight
increase and decrease. This is because an increase rate in a
diameter of the package P slows down as the diameter of the package
10 P becomes larger.
[0043] In the present embodiment, the unit control section 40
is configured to determine whether or not straight winding has
occurred, based on the decrease amount in the package wind number.
A principle that enables detection of straight winding based on a
15 decrease amount in the package wind number will be described with
reference to FIGS. 6(a) to 6(c) and 7(a) and 7(b), with a case, as
an example, where the package P is a cone-wound package (a
frustoconical package whose winding diameter gradually increases
or decreases in the axial direction).
20 [0044] FIGS. 6(a) to 6(c) are schematic front views
illustrating a wound state of the yarn Y. FIG. 6(a) illustrates
a state where the yarn Y is normally wound, FIG. 6(b) illustrates
a state where straight winding B1 occurs at an end part on a largediameter side of the cone-wound package P, and FIG. 6(c)
25 illustrates a state where straight winding B2 occurs at an end
part on a small-diameter side of the cone-wound package P. FIGS.
7(a) and 7(b) are graphs illustrating transition of a decrease
amount in a package wind number when straight winding occurs. FIG.
7(a) illustrates when straight winding occurs on the large30 diameter side of the cone-wound package P, and FIG. 7(b)
illustrates when straight winding occurs on the small-diameter
side of the cone-wound package P.
[0045] As illustrated in FIG. 6(a), when the yarn Y is wound
normally and no straight winding has occurred, a package P having
35 a desired shape is formed. At this time, the package P is in
12
contact with the traverse drum 32 over substantially the entire
region in the axial direction (traverse direction). However,
strictly speaking, a contact pressure differs depending on a
position in the axial direction, and the contact pressure is
5 maximized in a central region C in the axial direction. The
package P is rotated by a rotational driving force of the traverse
drum 32, and the rotational driving force is transmitted to the
package P via the central region C where the contact pressure is
maximized. That is, the number of rotations of the package P and
10 further the package wind number are determined by a diameter Pd of
the central region C. Note that the central region C where the
contact pressure is maximized is determined by a relationship with
a position of a centroid position of the package P, and does not
always coincide exactly with an axial center of the package P.
15 [0046] When the package wind number is Pw, the drum wind
number is Dw, and the diameter of the traverse drum 32 is Dd, Pw
= Dw × Dd/Pd, Equation (1), is satisfied.
Further, when the number of rotations of the package P is Pr
and the number of rotations of the traverse drum 32 is Dr, since
20 a peripheral speed of the package P is equal to a peripheral speed
of the traverse drum 32, Pd × Pr = Dd × Dr, Equation (2), is
satisfied.
From Equations (1) and (2), the following Equation (3) is
satisfied:
25 Pw = Dw × Pr/Dr, Equation (3)
[0047] As already described, since the drum wind number Dw is
a constant value determined by the type of the traverse drum 32,
the package wind number Pw can be calculated from Equation (3) as
long as the number of rotations Pr of the package P and the number
30 of rotations Dr of the traverse drum 32 are known. As described
above, the winding unit 2 is provided with the drum rotation sensor
34 that detects the number of rotations Dr of the traverse drum
32, and the package rotation sensor 35 that detects the number of
rotations Pr of the package P. Therefore, it is possible to
35 calculate the package wind number Pw without adding a new sensor.
13
Regarding the drum wind number Dw, the unit control section 40
acquires the drum wind number Dw on the basis of the type of the
traverse drum 32 inputted by an operator.
[0048] Next, how the package wind number changes when straight
5 winding occurs in the package P will be described. As illustrated
in FIG. 6(b), when the straight winding B1 occurs at the end part
on the large-diameter side of the cone-wound package P, the contact
pressure is maximized in a formation area A1 of the straight
winding B1. Therefore, the position at which the rotational
10 driving force is transmitted from the traverse drum 32 to the
package P moves from the central region C to the formation area A1
on the large-diameter side. As described above, when the
transmission position of the rotational driving force moves all at
once to the large-diameter side, the number of rotations of the
15 package P during one rotation of the traverse drum 32 rapidly
decreases, and further, the package wind number rapidly decreases.
That is, when the straight winding B1 occurs on the large-diameter
side of the cone-wound package P, the decrease amount in the
package wind number increases rapidly as illustrated in FIG. 7(a).
20 [0049] Whereas, as illustrated in FIG. 6(b), when the straight
winding B2 occurs at the end part on the small-diameter side of
the cone-wound package P, the contact pressure is maximized in a
formation area A2 of the straight winding B2. Therefore, the
position at which the rotational driving force is transmitted from
25 the traverse drum 32 to the package P moves from the central region
C to the formation area A2 on the small-diameter side. As
described above, when the transmission position of the rotational
driving force moves all at once to the small-diameter side, the
number of rotations of the package P during one rotation of the
30 traverse drum 32 rapidly increases, and further, the package wind
number rapidly increases. That is, when the straight winding B2
occurs on the small-diameter side of the cone-wound package P, the
decrease amount in the package wind number decreases rapidly as
illustrated in FIG. 7(a). Note that the fact that the decrease
35 amount in the package wind number is a negative value means that
14
the package wind number is increasing.
[0050] Such a rapid increase or decrease in the decrease
amount in the package wind number is due to a rapid change in the
number of rotations of the package P. Therefore, it seems that
5 the straight winding can be detected by simply monitoring the
number of rotations of the package P. However, for the purpose of
avoiding an occurrence of ribbon winding (a phenomenon that the
yarn Y is wound along a same path on a peripheral surface of the
package P), the number of rotations of the traverse drum 32 may be
10 intentionally changed during winding of the yarn Y. When the
number of rotations of the traverse drum 32 is changed, the number
of rotations of the package P also is changed accordingly.
Therefore, monitoring the number of rotations of the package P
alone for detection of straight winding may cause erroneous
15 detection that straight winding is occurring even when the number
of rotations of the traverse drum 32 is intentionally changed. In
this regard, by monitoring the package wind number in which the
number of rotations of the traverse drum 32 is also taken into
account, it is possible to improve the accuracy of detecting
20 straight winding.
[0051] FIGS. 8(a) and 8(b) are graphs illustrating transition
of a decrease amount in a package wind number, and threshold values.
FIG. 8(a) illustrates a decrease amount in the package wind number
during normal winding and threshold values, and FIG. 8(b)
25 illustrates a decrease amount in the package wind number when
straight winding occurs and threshold values. A first threshold
value is a threshold value for detecting that a decrease amount in
the package wind number has increased rapidly, that is, detecting
that straight winding has occurred on the large-diameter side of
30 the cone-wound package P. For the first threshold value, a value
larger than a decrease amount in the package wind number during
normal winding is set. Whereas, a second threshold value is a
threshold value for detecting that a decrease amount in the package
wind number has decreased rapidly, that is, detecting that straight
35 winding has occurred on the small-diameter side of the cone-wound
15
package P, For the second threshold value, a value smaller than a
decrease amount in the package wind number during normal winding
is set. In the example illustrated in FIGS. 8(a) and 8(b), the
first threshold value is set in a plurality of steps substantially
5 in accordance with transition of the decrease amount in the package
wind number during normal winding, and the second threshold value
is set to a constant value. For the first threshold value and the
second threshold value, a value determined in advance by taking
into account the yarn count and the like is stored, but may be set
10 by an operator. The unit control section 40 stores the first
threshold value and the second threshold value.
[0052] Based on: the number of rotations Dr of the traverse
drum 32 detected by the drum rotation sensor 34; the number of
rotations Pr of the package P detected by the package rotation
15 sensor 35; and the drum wind number Dw at a predetermined time
interval (for example, every two seconds), the unit control section
40 obtains the package wind number Pw, and calculates the decrease
amount in the package wind number Pw in 10 seconds. Then, the
calculated decrease amount in the package wind number Pw is
20 compared with the first threshold value and the second threshold
value. When the decrease amount in the package wind number Pw
exceeds the first threshold value, it is determined that straight
winding has occurred on the large-diameter side of the cone-wound
package P, the alarm section 41 is activated, and winding of the
25 yarn Y is stopped. When the decrease amount in the package wind
number Pw is less than the second threshold value, it is determined
that straight winding has occurred on the small-diameter side of
the cone-wound package P, the alarm section 41 is activated, and
winding of the yarn Y is stopped. When the decrease amount in the
30 package wind number Pw is equal to or greater than the second
threshold value or equal to or less than the first threshold value,
it is determined that the yarn Y has been wound normally, and
winding of the yarn Y is continued.
[0053] As illustrated in FIG. 8(b), when the first threshold
35 value and the second threshold value are actually applied, it has
16
been possible to detect, except for the first straight winding
that has occurred on the small-diameter side of the cone-wound
package P, all the remaining straight windings. Of course, if the
second threshold value is set a little higher, the first straight
5 winding can also be detected, and the detection accuracy of
straight winding can be improved by appropriately adjusting the
first threshold value and the second threshold value. In the
present embodiment, the first threshold value is set in a plurality
of steps, and the second threshold value is set to a constant
10 value. However, the first threshold value and the second threshold
value can be freely set. For example, the first threshold value
and the second threshold value may be set so as to gradually
decrease in accordance with transition of the decrease amount in
the package wind number during normal winding.
15 [0054] Meanwhile, when straight winding occurs in the central
region C (or in the vicinity thereof) of the cone-wound package P,
the transmission position of the rotational driving force from the
traverse drum 32 to the package P does not move all at once as
when the straight winding occurs on the large-diameter side and
20 the small-diameter side of the cone-wound package P. Therefore,
when straight winding occurs in the central region C of the conewound package P, there is no such a rapid change in the decrease
amount in the package wind number as illustrated in FIGS. 7(a) and
7(b), and therefore it is difficult to detect the straight winding.
25 However, in the case of the cone-wound package P, straight winding
tends to occur to be biased to one of the large-diameter side and
the small-diameter side. Therefore, being incapable of detecting
an occurrence of straight winding in the central region C does not
matter much.
30 [0055] (Effect)
The winding unit 2 of the present embodiment includes the
unit control section 40 that determines whether or not straight
winding has occurred based on the package wind number. According
to such a winding unit 2, it is possible to detect an occurrence
35 of straight winding as long as the package wind number is obtained.
17
The package wind number can be calculated from the number of
rotations of the traverse drum 32 and the number of rotations of
the package P. The sensors (the drum rotation sensor 34 and the
package rotation sensor 35) for detection of these numbers of
5 rotations are generally provided on the winding unit 2. Therefore,
an occurrence of straight winding can be detected even when no
traverse sensor or yarn speed sensor is provided.
[0056] In the winding unit 2 of the present embodiment, the
unit control section 40 determines whether or not straight winding
10 has occurred, based on a decrease amount in the package wind number
during a predetermined time (10 seconds). As described above,
when straight winding occurs, the package wind number rapidly
changes. Therefore, by using a decrease amount in the package
wind number as a determination criterion of an occurrence of
15 straight winding, it is possible to appropriately determine
whether or not straight winding has occurred.
[0057] In the winding unit 2 of the present embodiment, the
unit control section 40 determines that straight winding has
occurred when the decrease amount in the package wind number in
20 the predetermined time exceeds a predetermined first threshold
value. According to this configuration, when straight winding
occurs on the large-diameter side of the cone-wound package P, the
occurrence of the straight winding can be detected satisfactorily.
[0058] In the winding unit 2 of the present embodiment, the
25 unit control section 40 determines that straight winding has
occurred when the decrease amount in the package wind number in
the predetermined time falls below a predetermined second
threshold value. According to this configuration, when straight
winding occurs on the small-diameter side of the cone-wound package
30 P, the occurrence of the straight winding can be detected
satisfactorily.
[0059] The winding unit 2 of the present embodiment is
provided with the alarm section 41 that notifies, when the unit
control section 40 determines that straight winding has occurred,
35 an operator of the fact. Providing such an alarm section 41 allows
18
the operator to immediately recognize an occurrence of straight
winding, making it possible to quickly respond to the occurrence
of the straight winding.
[0060] In the winding unit 2 of the present embodiment, when
5 the unit control section 40 determines that straight winding has
occurred, the unit control section 40 controls to stop winding of
the yarn Y onto the package P. This configuration can minimize an
amount of the yarn Y wound around the package P in a straight
winding state.
10 [0061] In the winding unit 2 of the present embodiment, the
yarn Y is wound around the cone-wound package P whose winding
diameter gradually increases or decreases in the axial direction.
As described above, when the package P is the cone-wound package,
when the straight winding occurs, the number of rotations of the
15 package P changes particularly rapidly with a change in the
position at which the rotational driving force is transmitted from
the traverse drum 32 to the package P. Therefore, the occurrence
of straight winding can be accurately detected.
[0062] In the winding unit 2 of the present embodiment, the
20 drum according to the present invention is the traverse drum 32 in
which the traverse groove 32a for traverse of the yarn Y is formed
on the peripheral surface. The wind number of the traverse drum
32 depends on a type of the drum and does not change during winding
of the yarn Y. Therefore, when the traverse drum 32 is used, the
25 package wind number can be easily obtained.
[0063] (Other embodiments)
Alternative embodiments in which various modifications are
made on the above-described embodiment will be described.
[0064] In the above-described embodiment, it is determined
30 whether or not straight winding has occurred, based on a decrease
amount indicating an amount of decrease in the package wind number
in 10 seconds. However, the decrease amount in the package wind
number is not limited to the decrease amount for 10 seconds, and
can be changed as appropriate. Further, a numerical value used
35 for determining whether or not the straight winding has occurred
19
is not limited to the decrease amount in the package wind number.
Other numerical values related to the package wind number, such as
the package wind number itself and a differential value of the
package wind number, may be used.
5 [0065] In the above-described embodiment, the unit control
section 40 determines whether or not straight winding has occurred.
However, the subject of the determination as to whether or not
straight winding has occurred is not limited to the unit control
section 40, but may be, for example, the machine control device 4.
10 [0066] In the above-described embodiment, when it is
determined that straight winding has occurred, the alarm section
41 is activated, and winding of the yarn Y by the winding unit 2
is stopped. However, the operation performed by the winding unit
2 when it is determined that the straight winding has occurred is
15 not limited to this.
[0067] In the above-described embodiment, the case where the
package P is the cone-wound package has been described. However,
it is also possible to apply the present invention to a cheese
winding package P (cylindrical package). In this case, a diameter
20 does not change rapidly as in the case of the cone-wound package,
even when a transmission position of a rotational driving force
changes. Therefore, a set value of a threshold value for
distinguishing between the normal winding and the occurrence of
straight winding is more severe than in the case of the cone-wound
25 package, but the same method as in the above-described embodiment
can also be adopted.
[0068] In the above-described embodiment, the drum of the
present invention is the traverse drum 32. However, the
configuration of the winding unit described in, for example, JP
30 2019-59601 A may be adopted. In this case, a touch roller of JP
2019-59601 A functions as the drum of the present invention, and
an arm-type traverse device is provided separately from the drum.

WE CLAIM:
1. A yarn winding device (2) configured to wind a yarn (Y)
around a package (P) by traversing the yarn (Y) while rotating a
drum (32) that is in contact with a peripheral surface of the
5 package (P), the yarn winding device (2) comprising:
a control section (40) that is adapted to determine whether
straight winding has occurred in which the yarn (Y) is intensively
wound around a part of a traverse area, based on a package wind
number (Pw) indicating how many rotations the package (P) makes
10 while the yarn (Y) is traversed back and forth once.
2. The yarn winding device (2) according to claim 1, wherein
the control section (40) is adapted to determine whether the
straight winding has occurred based on a change amount in the
15 package wind number (Pw) in a predetermined time.
3. The yarn winding device (2) according to claim 2, wherein
the control section (40) is adapted to determine whether the
straight winding has occurred based on, as the change amount, a
20 decrease amount in the package wind number (Pw) in a predetermined
time.
4. The yarn winding device (2) according to claim 3, wherein,
when a decrease amount in the package wind number (Pw) in the
25 predetermined time exceeds a predetermined first threshold value,
the control section (40) is adapted to determine that the straight
winding has occurred.
5. The yarn winding device (2) according to claim 3 or 4,
30 wherein, when the decrease amount in the package wind number (Pw)
in the predetermined time falls below a predetermined second
threshold value, the control section (40) is adapted to determine
that the straight winding has occurred.
35 6. The yarn winding device (2) according to any one of
21
claims 1 to 5, wherein an output section is provided that is
adapted to notify an operator of an occurrence of the straight
winding when the control section (40) determines that the straight
winding has occurred.
5
7. The yarn winding device (2) according to any one of
claims 1 to 6, wherein, when it is determined that the straight
winding has occurred, the control section (40) is adapted to
control to stop winding of the yarn (Y) onto the package (P).
10
8. The yarn winding device (2) according to any one of
claims 1 to 7, wherein the yarn (Y) is wound on a cone-wound
package (P) whose winding diameter gradually increases or
decreases in an axial direction.
15
9. The yarn winding device (2) according to any one of
claims 1 to 8, wherein the drum (32) is a traverse drum (32) in
which a traverse groove (32a) for traverse of the yarn (Y) is
formed on a peripheral surface.
20
10. An automatic winder (1), wherein a plurality of the
yarn winding devices (2) according to any one of claims 1 to 9 are
arranged.
25 11. A method of operating a yarn winding device (2) winding
a yarn (Y) around a package (P) by traversing the yarn (Y) while
rotating a drum (32) that is in contact with a peripheral surface
of the package (P), characterized by
determining whether straight winding has occurred in which
30 the yarn (Y) is intensively wound around a part of a traverse area,
based on a package wind number (Pw) indicating how many rotations
the package (P) makes while the yarn (Y) is traversed back and
forth once.
35 12. The method according to claim 11, characterized by
22
determining whether the straight winding has occurred based on a
change amount in the package wind number (Pw) in a predetermined
time.
5 13. The method according to claim 12, characterized by
determining whether the straight winding has occurred based on, as
the change amount, a decrease amount in the package wind number
(Pw) in a predetermined time.
10 14. The method according to claim 13, wherein, when a
decrease amount in the package wind number (Pw) in the
predetermined time exceeds a predetermined first threshold value,
determining that the straight winding has occurred.
15 15. The method according to claim 13 or 14, wherein, when
the decrease amount in the package wind number (Pw) in the
predetermined time falls below a predetermined second threshold
value, determining that the straight winding has occurred.
20 16. The method according to any one of claims 11 to 15,
characterized by notifying an operator of an occurrence of the
straight winding when determining that the straight winding has
occurred.
25 17. The method according to any one of claims 11 to 16,
characterized by, when it is determined that the straight winding
has occurred, stopping winding of the yarn (Y) onto the package