TECHNICAL FIELD
[0001] The present invention relates mainly to a yarn winding device which winds a yarn
to form a package.
BACKGROUND ART
[0002] In a yarn winding device such as an automatic winder, a configuration has been conventionally
known in which a package is rotatably supported via a bearing and the package is driven
in rotation while being in contact with a traverse drum to thereby rotate the package
and thus wind a yarn.
[0003] In such a yarn winding device, Patent Document 1 discloses a method for calculating
a wound-yarn volume and the like during formation of a package. According to a configuration
of the Patent Document 1, a wound-yarn volume δ, a package diameter d
sp, and the like, are calculated based on a measured value of a rotation speed of the
package, a measured value of a rotation speed of a traverse drum, a drum diameter
of the traverse drum, and the like. A progress of the wound-yarn volume δ over the
package diameter d
sp is recorded in a memory, or displayed on a display. The Patent Document 1 also discloses
a configuration in which a control for returning a winding density to a normal value
by, for example, decreasing a drive motor speed is performed when an actual value
of the wound-yarn volume δ calculated is less than a target value because it means
that a traverse-wound package is formed at an extremely high winding density.
PRIOR-ART DOCUMENTS
PATENT DOCUMENTS
[0004]
Patent Document 1: Japanese Patent Application Laid-Open No. 10-72168 (1998)
DISCLOSURE OF THE INVENTION
PROBLEMS TO BE SOLVED BY THE INVENTION
[0005] Here, in a yarn winding device configured to rotatably support a package by a bearing
as described above, if the package cannot smoothly rotate due to a failure of the
bearing or the like, an outer circumferential surface of the package is frictioned
with a rotating traverse drum, which may cause damage or heat generation. Therefore,
in a case where such an abnormal package rotation occurs, it is preferred to find
the abnormal package rotation at an early stage and take some measures.
[0006] Thus, as a method for detecting an abnormal package rotation, it is conceivable to
set a lower limit value (threshold value) of an allowable rotation speed of a package
in consideration of an appropriate margin and examine whether or not a measured value
of a current rotation speed of the package is less than the threshold value.
[0007] However, a determination of the threshold value is not easy. In the yarn winding
device, a yarn is often wound while winding conditions (such as a diameter of a yarn
and a shape of the package) are variously changed as need arises. However, calculating
and re-setting the threshold value at the operator side each time the yarn winding
conditions are changed requires a lot of time and effort. On the other hand, equally
applying a common threshold value under any yarn winding conditions inevitably requires
a large margin to make determination conditions very lenient, which causes a deterioration
of the accuracy of detection of an abnormal package rotation.
[0008] In the configuration of the Patent Document 1 described above, the wound-yarn volume
δ is calculated in relation to the package diameter d
sp, not for the detection of an abnormal rotation, but because the progress of the actual
value of the wound-yarn volume δ is related to the yarn winding density which is an
important characteristic value of the traverse-wound package. Additionally, in the
Patent Document 1, since the package diameter d
sp is set based on the measured value of the rotation speed of the package and the measured
value of the rotation speed of the traverse drum (not set based on a diameter of the
yarn, a shape of the package, and the like), if an abnormal package rotation occurs,
the value of the package diameter d
sp calculated is deviated from an actual value. Therefore, the configuration of the
Patent Document 1 cannot appropriately detect the above-described abnormal package
rotation and cannot inform a person nearby of the abnormal package rotation.
[0009] The present invention is made in view of the circumstances described above, and an
object of the present invention is to provide a yarn winding device capable of automatically
detecting an abnormal package rotation with a high accuracy.
MEANS FOR SOLVING THE PROBLEMS AND EFFECTS THEREOF
[0010] The problem to be solved by the present invention is as described above, and next,
means for solving the problem and effects thereof will be described.
[0011] According to an aspect of the present invention, a yarn winding device having the
following configuration is provided. The yarn winding device includes a winding unit
and a control section. A rotatable drum is provided in the winding unit. The winding
unit performs a yarn winding operation by causing a package to be rotated by the drum.
The control section controls the winding unit. The control section includes a theoretical
package calculation section and a computation section. The theoretical package calculation
section calculates the theoretical number of package rotations. The computation section
determines an alarm threshold value for determining an abnormal package rotation,
based on the theoretical number of package rotations.
[0012] Thereby, the alarm threshold value can be set automatically, and therefore a yarn
winding device can be operated with an appropriate alarm threshold value being flexibly
set.
[0013] In the yarn winding device, it is preferable that the theoretical package calculation
section calculates a theoretical package diameter based on a yarn winding condition,
and calculates the theoretical number of package rotations based on the theoretical
package diameter and a yarn winding speed,
[0014] Thereby, an appropriate alarm threshold value in accordance with the yarn winding
condition can be set. Additionally, a change of the yarn winding condition can be
easily responded to.
[0015] In the yarn winding device, it is preferable that the theoretical package diameter
is the theoretical package diameter at a time of full-winding.
[0016] Thereby, an alarm threshold value applicable under the same yarn winding condition
can be obtained merely by obtaining, only once, the theoretical number of package
rotations based on this theoretical package diameter. This can simplify a process
performed by the theoretical package calculation section and the computation section.
[0017] In the yarn winding device, it is preferable that the yarn winding condition includes
a kind of a yarn to be wound and a shape of a package to be formed.
[0018] This enables the theoretical package diameter to be accurately calculated,
[0019] It is preferable that the yarn winding device is configured as follows. The winding
unit further includes a winding length measurement section and a winding length output
section. The winding length measurement section measures a winding length which is
a length of a wound part of a yarn. The winding length output section outputs the
winding length measured by the winding length measurement section. The control section
includes a winding length input section. The winding length outputted by the winding
length output section is inputted to the winding length input section. The theoretical
package calculation section calculates a theoretical package diameter based on a yarn
winding condition and the winding length, and calculates the theoretical number of
package rotations at a time when the winding length is measured based on the theoretical
package diameter and a yarn winding speed.
[0020] Thereby, the theoretical package diameter at a time point in the middle of the winding
can be obtained based on the winding length. Therefore, even in a case where the package
diameter and the number of package rotations are changed in a time period from a start
to an end of the winding, an appropriate alarm threshold value can be obtained.
[0021] In the yarn winding device, it is preferable that the alarm threshold value is updated
each time the theoretical number of package rotations changes,
[0022] That is, although the number of package rotations can be changing every moment in
the middle of the yarn winding, adoption of the above-described configuration enables
an abnormal package rotation to be detected at any time point with a good accuracy.
[0023] Here, in the yarn winding device, it is also acceptable that the alarm threshold
value is switched in stages in accordance with a change of the theoretical number
of package rotations.
[0024] Thereby, the yarn winding device can be operated while the alarm threshold value
is switched in accordance with a state of progress of the yarn winding, without considerably
increasing a load on the theoretical package calculation section and the computation
section.
[0025] It is preferable that the yarn winding device is configured as follows. The control
section includes a threshold value output section. The threshold value output section
outputs the alarm threshold value. The winding unit includes a threshold value input
section, a number-of-package-rotations measurement section, an alarm determination
section, and an alarm section. The alarm threshold value is inputted to the threshold
value input section. The number-of-package-rotations measurement section measures
the number of package rotations. The alarm determination section compares the alarm
threshold value with the number of package rotations measured by the number-of-package-rotations
measurement section, and performs an alarm determination. The alarm section generates
an alarm in accordance with the determination performed by the alarm determination
section,
[0026] Thereby, the alarm generated by the alarm section allows an operator to know occurrence
of an abnormal package rotation at an early stage. Additionally, since the alarm section
is provided in the winding unit, the operator can easily identify the winding unit
in which the abnormal package rotation is occurring.
[0027] In the yarn winding device, it is preferable that the control section is a machine
control device which controls a plurality of winding units.
[0028] Thereby, the same operation can be performed on a plurality of winding units by using
the machine control device. Therefore, a working time can be shortened.
[0029] According to another aspect of the present invention, a method for determining an
alarm threshold value for detecting an abnormal package rotation, which includes the
following steps, is provided. In a theoretical package diameter calculation step,
a theoretical package diameter is calculated based on a kind of a yarn to be wound,
a shape of a package, and a yarn length required for forming the package. In a theoretical-number-of-package-rotations
calculation step, the theoretical number of package rotations is calculated based
on the theoretical package diameter. In an alarm threshold value determination step,
an alarm threshold value is determined based on the theoretical number of package
rotations.
[0030] This enables the alarm threshold value to be automatically set in accordance with
a yarn winding condition, and therefore a yarn winding device can be operated with
an appropriate alarm threshold value being flexibly set.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031]
FIG. 1 is a schematic elevation view of an automatic winder according to an embodiment
of the present invention;
FIG. 2 is an elevation view schematically showing a winding unit included in the automatic
winder;
FIG. 3 is a block diagram showing a main configuration of a machine control device
and a winding unit;
FIG. 4 is a graph for conceptual explanation of a relationship between an alarm threshold
value and a package diameter according to the embodiment of the present invention;
FIG. 5 is a graph for conceptual explanation of a relationship between an alarm threshold
value and a package diameter according to a first modification;
FIG. 6 is a graph for conceptual explanation of a relationship between an alarm threshold
value and a package diameter according to a second modification; and
FIG. 7 is an elevation view showing a winding unit configured such that a yarn speed
is detected by a yarn speed sensor.
BEST MODE FOR CARRYING OUT THE INVENTION
[0032] Next, an embodiment of the present invention will be described with reference to
the drawings. FIG. 1 is a schematic elevation view of an automatic winder 60 according
to an embodiment of the present invention. FIG. 2 is an elevation view schematically
showing a winding unit 16 included in the automatic winder 60. FIG. 3 is a block diagram
showing a main configuration of a machine control device 11 and the winding unit 16.
[0033] As shown in FIG. 1, the automatic winder (yarn winding device) 60 includes a machine
control device (control section) 11, a plurality of winding units 16 arranged side
by side, and an automatic doffing device 51.
[0034] Each of the winding units 16 is configured such that a yarn 20 unwound from a yarn
feed bobbin 21 is wound on a winding bobbin while being traversed by a traverse drum
41 so that a package 30 is formed. The winding unit 16 also has a clearer (yarn quality
measuring instrument) 42 which monitors a diameter and the like of the running yarn
20, and when the clearer 42 detects a defect of the yarn 20, the defect can be removed.
[0035] When the package reaches full winding in each winding unit 16, the automatic doffing
device 51 travels to a position of the winding unit 16, and picks up the full winding
package while supplying an empty bobbin. This operation of the automatic doffing device
51 is controlled by the machine control device 11.
[0036] In the following, a specific configuration of the winding unit 16 will be described.
As shown in FIG. 2, in the winding unit 16, in a yarn running path between the yarn
feed bobbin 21 and the traverse drum 41, an unwinding assist device 12, a tension
applying device 13, a splicing device 14, and the clearer 42 are arranged in the mentioned
order from the yarn feed bobbin 21 side.
[0037] The unwinding assist device 12 assists unwinding of the yarn from the yarn feed bobbin
21 by moving down a restricting member 40 overlying a core tube of the yarn feed bobbin
21 in conjunction with the unwinding of the yarn 20 from the yarn feed bobbin 21.
The restricting member 40 is brought into contact with a balloon, which is formed
at an upper portion of the yarn feed bobbin 21, by the rotation and a centrifugal
force of the yarn 20 unwound from the yarn feed bobbin 21, and appropriately controls
the size of the balloon, to thereby assist the unwinding of the yarn 20. A not-shown
sensor for detecting a chase portion of the yarn feed bobbin 21 is provided near the
restricting member 40. When the sensor detects moving down of the chase portion, the
restricting member 40 is controlled so as to be followingly moved down by an air cylinder
(not shown), for example.
[0038] The tension applying device 13 applies a predetermined tension to the running yarn
20. As the tension applying device 13, for example, gate type one may be used in which
movable comb-like teeth are arranged against fixed comb-like teeth. The comb-like
teeth of the movable side can be rotated by, for example, a rotary type solenoid such
that both of the comb-like teeth are brought into an engaged state or an open state.
[0039] A constant tension is applied to the yarn 20 which is being wound, by the tension
applying device 13, and thus the quality of the package 30 can be increased. As the
tension applying device 13, not only the above-mentioned gate type one but also disk
type one may be adopted, for example.
[0040] The splicing device 14 splices a lower yarn at the yarn feed bobbin 21 side and an
upper yarn at the package 30 side, when yarn cutting which is performed by the clearer
42 upon detection of a yarn defect is performed, when the yarn unwound from the yarn
feed bobbin 21 is broken, or the like. As such a splicing device which splices the
upper yarn and the lower yarn, one using a fluid such as compressed air or one of
mechanical type may be adopted.
[0041] The clearer 42 has a clearer head 49 in which a not-shown sensor for detecting the
diameter of the yarn 20 is disposed, and an analyzer 47 which processes a yarn thickness
signal outputted from the sensor. The clearer 42 monitors the yarn thickness signal
from the sensor, and thereby detects a yarn defect (yarn fault) such as a slab. A
cutter 39 is provided near the clearer head 49, for immediately cutting the yarn 20
when the clearer 42 detects a yarn defect.
[0042] A lower yarn guide pipe 25 which captures the lower yarn at the yarn feed bobbin
21 side and guides the lower yarn to the splicing device 14, and an upper yarn guide
pipe 26 which captures the upper yarn at the package 30 side and guides the upper
yarn to the splicing device 14 are provided at the lower side and the upper side of
the splicing device 14, respectively. The lower yarn guide pipe 25 and the upper yarn
guide pipe 26 are rotatable about shafts 33 and 35, respectively. A suction port 32
is formed at a distal end of the lower yarn guide pipe 25, and a suction mouth 34
is provided at a distal end of the upper yarn guide pipe 26. An appropriate negative-pressure
source is connected to each of the lower yarn guide pipe 25 and the upper yarn guide
pipe 26, to cause suction flows in the suction port 32 and the suction mouth 34 so
that yarn ends of the upper yarn and the lower yarn can be sucked and captured.
[0043] A cradle 23 has a pair of cradle arms 61 and 62. The cradle arms 61 and 62 are supported
by a hinge shaft 48, and rotatable in directions moving toward and away from the traverse
drum 41.
[0044] Rotating holders 63 and 64 are attached to distal ends of the pair of cradle arms
61 and 62. The rotating holders 63 and 64 are arranged so as to be opposed to each
other, and each of the rotating holders 63 and 64 is rotatably supported via a not-shown
bearing. In this configuration, a winding bobbin 22 is mounted so as to be interposed
between the two rotating holders 63 and 64, and thereby the winding bobbin 22 can
be rotatably supported on the cradle 23.
[0045] The cradle 23 has a package rotation sensor 72 for detecting the rotation of the
package 30 (winding bobbin 22) mounted in the cradle 23. The package rotation sensor
72 is configured as a rotary encoder for example, and electrically connected to a
unit control section 70. The package rotation sensor 72 outputs a pulse signal to
the unit control section 70 each time the rotating holder 63 at one side is rotated
at a predetermined angle.
[0046] The traverse drum 41 is arranged near the cradle 23, and rotatably supported. A spiral-shaped
traverse groove for traversing the yarn 20 in a predetermined width is formed on an
outer circumferential surface of the traverse drum 41. An output shaft of a drum drive
motor 53 is coupled to the traverse drum 41, and the drum drive motor 53 is controlled
by a motor control section 74. The motor control section 74 controls the rotation
of the drum drive motor 53 based on a signal from the unit control section 70. When
driven by the drum drive motor 53, the traverse drum 41 causes the winding bobbin
22 or the package 30 which is in contact with the outer circumferential surface of
the traverse drum 41 to be rotated.
[0047] A drum rotation sensor 73 is arranged near the traverse drum 41, and the drum rotation
sensor 73 is electrically connected to the unit control section 70, The drum rotation
sensor 73 is configured as a rotary encoder for example, and outputs a rotation pulse
signal to the unit control section 70 each time the traverse drum 41 rotates at a
predetermined angle. The unit control section 70 measures the number of pulses per
a predetermined time period, and thereby can obtain the number of rotations of the
traverse drum 41.
[0048] Next, a control of each winding unit 16 will be described. As shown in FIGS. 2 and
3, the package rotation sensor (a number-of-package-rotations measurement section)
72, the drum rotation sensor (a winding length measurement section) 73, and the motor
control section 74 are connected to the unit control section 70.
[0049] The unit control section 70 includes a CPU (Central Processing Unit), a ROM (Read
Only Memory), and a RAM (Random Access Memory) which are not shown. The unit control
section 70 also includes an I/O port (a threshold value input section, a winding length
output section, and an input/output section) 78 capable of transmission and reception
of data, as shown in FIG. 3.
[0050] A control program for controlling each configuration (for example, the motor control
section 74 and the like) of the winding unit 16 is stored in the ROM. The CPU reads
the control program stored in the ROM out into the RAM, and executes the control program,
to thereby control each configuration so that winding of the yarn can be appropriately
performed. In other words, the above-described hardware and software cooperate with
each other to build a winding control section 75 for controlling winding of the yarn
in the unit control section 70.
[0051] The unit control section 70 includes, in addition to the above-mentioned winding
control section 75, an alarm determination section 76 which determines whether or
not the package is in abnormal rotation. Details of this determination will be described
later.
[0052] The winding unit 16 includes an alarm section 77 capable of generating an alarm by
a light, a sound, or the like. Examples of a specific configuration of the alarm section
77 include a lamp, a buzzer, and the like. The alarm section 77 is electrically connected
to the unit control section 70. In this configuration, when the alarm determination
section 76 determines that there is an abnormal rotation of the package, the unit
control section 70 outputs an alarm signal to the alarm section 77 to generate an
alarm, thus alerting an operator.
[0053] As shown in FIGS. 1 and 3, the machine control device 11 includes a theoretical package
calculation section 27, a computation section 17, a display section 18, and an input
key 19. Similarly to the unit control section 70, the machine control device 11 also
includes a CPU, a ROM, a RAM, and an I/O port (a threshold value output section, a
winding length input section, and an input/output section) 15.
[0054] The I/O port 15 of the machine control device 11 is connected via an appropriate
communication line to the I/O port 78 of the unit control section 70 provided in each
winding unit 16. This configuration enables the machine control device 11 to transmit
various yarn winding conditions to the unit control section 70 of each winding unit
16, to set the yarn winding conditions. The machine control device 11 can also receive,
from the unit control section 70 of each winding unit 16, information (yarn winding
status information) concerning a current yarn winding status in the winding unit 16.
[0055] This configuration allows the machine control device 11 to collectively manage the
plurality of winding units 16 included in the automatic winder 60. To be specific,
the machine control device 11 can transmit various yarn winding conditions to the
unit control section 70 of each winding unit 16, to set the yarn winding conditions.
Additionally, the machine control device 11 can also receive, from the unit control
section 70 of each winding unit 16, the information concerning the current yarn winding
status in the winding unit 16.
[0056] Examples of the yarn winding conditions set in the winding unit 16 include items
concerning a kind of the yarn to be wound, a winding speed, a count, a winding tension,
a shape of the package, a yarn length required for forming the package, a weight of
the package, a yarn defect, and the like. Examples of the yarn winding status information
transmitted from the winding unit 16 to the machine control device 11 include the
current number of rotations of the package 30, the current number of rotations of
the traverse drum 41, a current length wound on the package 30, a status of occurrence
of a yarn breakage, a status of detection of a yarn defect, and the like,
[0057] Specifically, the operator can set the yarn winding conditions by displaying a yarn
winding condition setting menu on the display section 18 of the machine control device
11 by an appropriate operation and inputting a numerical value through the input key
19. Set values concerning the yarn winding conditions may be individually transmitted
to a designated winding unit 16, or may be collectively transmitted to all the winding
units 16.
[0058] Next, a configuration for detecting occurrence of an abnormal rotation of the package
will be described.
[0059] Before starting to wind the yarn, the operator inputs necessary ones of the items
of the yarn winding conditions, to the machine control device 11. Then, the theoretical
package calculation section 27 of the machine control device 11 obtains, by calculation,
a relationship between a yarn winding length and a theoretical package diameter, based
on necessary information (for example, the kind (count) of the yarn to be wound, the
shape of the package, the density (specific gravity) of the package) among the set
items. That is, when the theoretical package diameter is defined as D and the yarn
winding length is defined as L, the theoretical package diameter D can be represented
as D=F(L) using a function F. The theoretical package calculation section 27 determines
the function F by calculation.
[0060] In this embodiment, the relationship between the theoretical package diameter and
the winding length is theoretically obtained based on information of the yarn winding
conditions, not based on a measured value. In a case where a cone-shaped package is
formed as in this embodiment, the diameter differs between one end side and the other
end side. The theoretical package diameter may be either a diameter at the larger
diameter side or a diameter at the smaller diameter side, or the theoretical package
diameter may be a diameter at a central portion in a shaft direction.
[0061] As represented by the aforementioned equation, the theoretical package diameter D
can be expressed as a function having the winding length L as a parameter. Accordingly,
once the aforementioned function F is obtained by calculation, then the theoretical
package diameter D at a time point of a winding length L can be obtained by obtaining
a function value of the function F with respect to this winding length L.
[0062] Next, an exemplary method for obtaining a relationship (that is, the aforementioned
function F) between the yarn winding length and the theoretical package diameter will
be described. In this example, information of the kind of the yarn, the shape of the
package, and the density (specific gravity) of the package is used in the calculation.
[0063] Hereinafter, an idea will be described. Firstly, since a weight per unit length can
be obtained from the kind of the yarn, this is multiplied by the winding length L,
so that the weight of the wound yarn can be obtained. Then, this is divided by the
density (specific gravity) of the package, so that the volume occupied by the wound
yarn can be obtained. Then, using the diameter and a traverse width of the winding
bobbin 22 which are known, the thickness of a yarn layer in a diameter direction required
for realizing the above-mentioned volume is calculated based on a geometric relationship,
to thereby obtain the theoretical package diameter. At a time point when the yarn
winding conditions are inputted by the operator, the theoretical package calculation
section 27 of the machine control device 11 calculates the relationship (function
F) between the yarn winding length and the theoretical package diameter in the above-described
manner, and stores an obtained result in a storage device such as the RAM.
[0064] The operator sets various conditions to the machine control device 11 and then instructs
a start of winding, and thereby winding in each winding unit 16 is started. In this
yarn winding, the drum rotation sensor 73 of each winding unit 16 outputs a pulse
signal (drum pulse) to the unit control section 70 each time the traverse drum 41
rotates at the predetermined angle. The unit control section 70 counts the drum pulse
from a time point when the yarn winding is started, to thereby obtain the accumulated
number of rotations of the traverse drum 41 since the yarn is started to be wound
on an empty bobbin.
[0065] Then, the unit control section 70 calculates the winding length (the length of the
yarn wound from a start of the package formation to the current time) by multiplying
the accumulated number mentioned above by the length of the yarn wound per one rotation
of the traverse drum 41. The length of the yarn per one rotation of the traverse drum
41 is a constant which is specific to the traverse drum 41, and is preset in the unit
control section 70. In this manner, in this embodiment, since the drum rotation sensor
73 detects the rotation of the traverse drum 41 to thereby obtain the yarn winding
length, it can be considered that the drum rotation sensor 73 substantially functions
as the winding length measurement section.
[0066] Then, the unit control section 70 outputs the obtained winding length (as the yarn
winding status information) from the I/O port 78 of the winding unit 16 to the I/O
port 15 of the machine control device 11. Since this process of outputting the winding
length is repeatedly performed at short time intervals, the most recent winding length
in each winding unit 16 is inputted to the machine control device 1 substantially
in real time.
[0067] The machine control device 11 applies the winding length L received by the I/O port
15 to the aforementioned equation, to thereby obtain the theoretical package diameter
D with respect to the winding length L at the time of the measurement.
[0068] Information inputted to the machine control device 1 by the operator before the yarn
winding is started includes a winding speed (a length of the yarn wound per unit time).
The machine control device 11 stores the inputted winding speed in a storage device
such as the RAM, and also transmits this winding speed to each winding unit 16 (unit
control section 70). The unit control section 70 of each winding unit 16 controls
the drum drive motor 53 through the winding control section 75 and the motor control
section 74, in order that the yarn can be wound at the received winding speed.
[0069] The theoretical package calculation section 27 provided in the machine control device
11 calculates the theoretical number of package rotations based on this winding speed
and the theoretical package diameter. The theoretical number of package rotations
is the number of rotations of the package which is theoretically obtained based on
the theoretical package diameter and the winding speed.
[0070] An exemplified method for obtaining the theoretical number of package rotations will
be shown. Firstly, the number of rotations of the traverse drum 41 which is required
for realizing the aforementioned winding speed is obtained using a yarn length per
one rotation of the traverse drum 41. Then, calculation is performed using the number
of rotations of the traverse drum 41 thus obtained, the diameter of the traverse drum
41, and the theoretical package diameter D with respect to the winding length L at
the time of the measurement, and thereby the theoretical number of package rotations
can be obtained.
[0071] As described above, in the machine control device 11, the most recent winding length
L in each winding unit 16 is obtained one after another. Each time the value of the
winding length L is updated in each winding unit 16, the theoretical package calculation
section 27 of the machine control device 11 re-calculates the theoretical package
diameter and the theoretical number of package rotations in the winding unit 16.
[0072] FIG. 4 shows a relationship between the theoretical number of package rotations and
the package diameter. FIG. 4 is a graph conceptually explaining a relationship between
an alarm threshold value and the package diameter. In FIG. 4, the horizontal axis
represents the package diameter, and the vertical axis represents the number of rotations.
[0073] When the yarn is wound at a constant winding speed (when the traverse drum 41 is
driven with a constant number of rotations), the theoretical number of package rotations
moderately and monotonically decreases as the package diameter increases, as shown
in FIG. 4. That is, at an initial stage of the yarn winding, the package diameter
is small and an angle of rotation of the package 30 per one rotation of the traverse
drum 41 is large, and consequently the number of package rotations shows a high value.
On the other hand, at a terminal stage of the yarn winding, the package diameter becomes
large and the angle of rotation of the package 30 per one rotation of the traverse
drum 41 becomes small, and therefore the number of package rotations shows a low value.
[0074] Then, based on this theoretical number of package rotations, the machine control
device 11 of this embodiment determines the alarm threshold value which is a criterion
for determining whether or not an abnormal package rotation is occurring. As this
alarm threshold value, conceivable is a value obtained by multiplying the theoretical
number of package rotations by a predetermined ratio (X %) which is less than 1, for
example. It is preferable that this ratio (the value of X) can be changed by the operator
operating the input key 19 of the machine control device 11, for example.
[0075] Each time the winding progresses and the theoretical number of package rotations
changes in each winding unit 16, the machine control device 11 re-calculates the alarm
threshold value as needed. FIG. 4 also shows a transition of the alarm threshold value
in a case where the alarm threshold value is determined by multiplying the theoretical
number of package rotations by a constant ratio as described above. The alarm threshold
value smoothly varies, following the change of the theoretical number of package rotations.
Accordingly, at any time point in the winding, whether or not an abnormal package
rotation is occurring can be accurately determined using an appropriate alarm threshold
value.
[0076] The calculated alarm threshold value is inputted from the I/O port 15 of the machine
control device 11 through the I/O port 78 of the winding unit 16 to the unit control
section 70. The unit control section 70 stores the inputted alarm threshold value
in a storage device such as the RAM.
[0077] On the other hand, during the yarn winding, each time the package 30 is rotated at
a predetermined angle, the package rotation sensor 72 outputs a rotation detection
signal (pulse signal) to the unit control section 70. The unit control section 70
counts the pulse signal in a predetermined time zone, to thereby obtain the number
of package rotations. In the following description, the number of package rotations
obtained in this manner will sometimes be referred to as the actual number of package
rotations.
[0078] FIG. 4 shows two examples of the actual number of package rotations. As shown in
this graph, normally, the actual number of package rotations obtained based on the
measured value is substantially coincident with the theoretical number of package
rotations. However, if, for example, a failure occurs in the bearing supporting the
rotating holders 63 and 64, the package 30 cannot be properly rotated. In this case,
the actual number of package rotations drastically decreases, and falls below the
alarm threshold value.
[0079] The alarm determination section 76 included in the unit control section 70 compares
the actual number of package rotations with the alarm threshold value during the yarn
winding. When the actual number of package rotations is equal to or greater than the
alarm threshold value, it means that the package is rotating in a good manner, and
therefore the alarm determination section 76 continues the aforesaid comparison process.
On the other hand, when the actual number of package rotations is smaller than the
alarm threshold value, the alarm determination section 76 outputs the alarm signal
to the alarm section 77. When the alarm signal is inputted, the alarm section 77 actually
generates an alarm to inform the operator of occurrence of abnormality. This allows
the operator to find occurrence of an abnormal package rotation at an early stage
and take appropriate measures.
[0080] In a case where the alarm determination section 76 generates the alarm signal (that
is, in a case where occurrence of an abnormal package rotation is detected), the winding
control section 75 immediately stops the drum drive motor 53 through the motor control
section 74. Immediately stopping the winding in this manner can avoid the traverse
drum 41 forcibly driving in rotation the package 30 which cannot be properly rotated.
Thus, damage to the package 30 and overload of the drum drive motor 53 can be prevented.
[0081] In this embodiment, the time zone in which the pulse signal of the package rotation
sensor 72 is counted in order to obtain the actual number of package rotations described
above is set in consideration of a disturb control performed by the unit control section
70.
[0082] In the following, the disturb control will be briefly described. When the number
of rotations of the traverse drum 41 and the number of rotations of the package becomes
integer multiples of each other during the yarn winding, a traverse cycle and a winding
cycle of the package are synchronized with each other, to cause a so-called ribbon
winding in which the wound yarn is gathered and stacked at the same position. In a
package in which such a ribbon winding occurs, ribbon-wound yarns are tangled with
each other, which causes a problem that a yarn breakage occurs when the yarn of the
package is unwound in a subsequent step, and the like. Therefore, to break this ribbon
winding, a method is known in which the speed of rotation of the traverse drum 41
is rapidly increased and decreased at a position near a diameter at which the ribbon
winding is occurring, to thereby cause a slip between the package and the traverse
drum 41, so that winding is performed while distributing yarn paths of the traversing
yarn. This is the disturb control.
[0083] Since the package 30 is slipped on the traverse drum 41 in the disturb control as
described above, the actual number of package rotations may become smaller than normal
in the course of the disturb process. Thus, if the speed at that moment is measured
as the actual number of package rotations, a reduction of the number of package rotations
which is caused simply by the disturb control may be erroneously determined to be
an abnormal package rotation.
[0084] Therefore, in this embodiment, the time zone in which the pulse signal of the package
rotation sensor 72 is counted in order to obtain the actual number of package rotations
is set to be a time period in accordance with a cycle of a speed-change caused by
the disturb control, By sufficiently ensuring a count time in this manner, an influence
of a phenomenon in which the number of package rotations is instantaneously reduced
by the disturb control is suppressed, and an erroneous determination of an abnormal
package rotation can be avoided.
[0085] The above description states that the alarm determination section 76 compares the
actual number of package rotations with the alarm threshold value, but in a precise
sense, the alarm determination section 76 compares the number of pulses, which corresponds
to the amount of rotations obtained by multiplying the number of rotations obtained
as the alarm threshold value by the length of the aforesaid time zone, with a counted
value of a pulse of the package rotation sensor 72 which is actually measured in the
aforesaid time zone. Thereby, the alarm determination section 76 determines whether
or not an abnormal package rotation is occurring. However, it can be substantially
considered that the above-described process eventually compares the numbers of rotations
with each other.
[0086] As described above, the automatic winder 60 of this embodiment includes the winding
units 16 and the machine control device 11. The traverse drum 41 is provided in each
of the winding units 16. In the winding unit 16, the package 30 is rotated by the
traverse drum 41 to perform winding of the yarn. The machine control device 11 controls
the winding units 16. The machine control device 11 includes the theoretical package
calculation section 27 and the computation section 17. The theoretical package calculation
section 27 calculates the theoretical number of package rotations. The computation
section 17 determines the alarm threshold value for determining an abnormal package
rotation, based on the aforesaid theoretical number of package rotations.
[0087] Thereby, the alarm threshold value can be set automatically, and therefore the automatic
winder 60 can be operated with an appropriate alarm threshold value being flexibly
set.
[0088] In the automatic winder 60 of this embodiment, the theoretical package calculation
section 27 calculates the theoretical package diameter based on the yarn winding conditions,
and calculates the theoretical number of package rotations based on the aforesaid
theoretical package diameter and the yarn winding speed.
[0089] Thereby, the theoretical number of package rotations in accordance with the yarn
winding conditions can be calculated. Additionally, for example, if the yarn winding
conditions are changed due to a change in a lot of the package, such a change can
be easily responded to.
[0090] In the automatic winder 60 of this embodiment, the yarn winding conditions include
the kind of the yarn to be wound and the shape of the package to be formed.
[0091] This enables an accurate calculation of the theoretical package diameter.
[0092] In the automatic winder 60 of this embodiment, the winding unit 16 further includes
the drum rotation sensor 73 and the I/O port 78. The drum rotation sensor 73 measures
the winding length which is the length of a wound part of the yarn. The I/O port 78
outputs the winding length measured by the drum rotation sensor 73, to the computation
section 17 of the machine control device 11. The machine control device 11 includes
the I/O port 15. The winding length outputted by the I/O port 78 is inputted to the
I/O port 15. The theoretical package calculation section 27 of the machine control
device 11 calculates the theoretical package diameter based on the yarn winding conditions
and the winding length, and calculates the theoretical number of package rotations
at the time when the winding length is measured, based on this theoretical package
diameter and the yarn winding speed.
[0093] Thereby, the alarm threshold value can be changed in accordance with an increase
of the winding length, during a time period from the start to the end of the yarn
winding. This enables an abnormal package rotation to be detected using a more appropriate
alarm threshold value.
[0094] In the automatic winder 60 of this embodiment, each time the theoretical number of
package rotations changes, the alarm threshold value is updated.
[0095] That is, although the number of package rotations can be changing every moment in
the middle of the yarn winding, adoption of the above-described configuration enables
an abnormal rotation of the package 30 to be accurately detected at any time point.
[0096] The automatic winder 60 of this embodiment is configured as follows. That is, the
I/O port 15 of the machine control device 11 outputs the alarm threshold value. The
winding unit 16 includes the I/O port 78, the package rotation sensor 72, the alarm
determination section 76, and the alarm section 77. The alarm threshold value is inputted
to the I/O port 78. The package rotation sensor 72 measures the number of package
rotations. The alarm determination section 76 compares the alarm threshold value with
the number of package rotations measured by the package rotation sensor 72, and performs
an alarm determination. The alarm section 77 generates an alarm based on the determination
performed by the alarm determination section 76.
[0097] Thus, the alarm generated by the alarm section 77 allows the operator to know occurrence
of an abnormal package rotation at an early stage. Additionally, since the alarm section
77 is provided in the winding unit 16, the operator can easily identify the winding
unit 16 in which the abnormal package rotation is occurring.
[0098] In the automatic winder 60 of this embodiment, the machine control device 11 controls
the plurality of winding units 16.
[0099] This allows the machine control device 11 to perform the same operation collectively
on the plurality of winding units 16, which can shorten a working time.
[0100] Next, a first modification of the above-described embodiment will be described.
[0101] FIG. 5 is a graph conceptually explaining a relationship between an alarm threshold
value and a package diameter according to the first modification.
[0102] In the above-described embodiment, the alarm threshold value is updated to a new
value as needed during the yarn winding, whereas in this modification, the alarm threshold
value is updated only once in a time period of forming one package,
[0103] Hereinafter, a specific description will be given. Before the yarn winding is started,
the theoretical package calculation section 27 of the machine control device 11 calculates
the theoretical number of package rotations corresponding to half the winding length
at a time of full-winding. The winding length (a yarn length required for forming
the package) at the time of full-winding is inputted in the machine control device
1 in advance. The computation section 17 previously obtains an alarm threshold value
(first alarm threshold value) corresponding to that theoretical number of package
rotations, and outputs it to the unit control section 70 of the winding unit 16.
[0104] Then, the yarn winding is started in the winding unit 16, The alarm determination
section 76 of the winding unit 16 detects an abnormal package rotation by using the
aforesaid first alarm threshold value.
[0105] As the winding progresses, the winding length outputted through the I/O port 78 by
the winding unit 16 increases. However, in this modification, the theoretical package
calculation section 27 and the computation section 17 of the machine control device
11 does not re-calculates the theoretical number of package rotations and the alarm
threshold value, unless the winding length reaches a predetermined value (specifically,
a value half the winding length at the time of full-winding). Accordingly, until the
yarn winding progresses to a certain degree, the alarm determination section 76 of
the winding unit 16 detects an abnormal package rotation by using a constant alarm
threshold value (first alarm threshold value) as a criterion.
[0106] When the winding length outputted from the winding unit 16 to the machine control
device 11 becomes equal to or larger than half the winding length at the time of full-winding,
the theoretical package calculation section 27 of the machine control device 11 calculates
the theoretical number of package rotations corresponding to the winding length at
the time of full-winding. Then, the computation section 17 calculates an alarm threshold
value (second alarm threshold value) corresponding to that theoretical number of package
rotations, and outputs it to the unit control section 70 of the winding unit 16. However,
the theoretical number of package rotations at the time of full-winding and the second
alarm threshold value may be, together with the first alarm threshold value and the
like, calculated in advance before the winding is started, and may be stored in the
RAM or the like.
[0107] When the new alarm threshold value is inputted to the unit control section 70 of
the winding unit 16, the alarm determination section 76 performs an alarm determination
using the new threshold value. After outputting the second alarm threshold value,
the machine control device 11 does not update the alarm threshold value until the
package 30 of this winding unit reaches full winding. Accordingly, in the winding
unit 16, an abnormal package rotation is detected by using a constant alarm threshold
value (second alarm threshold value) as a criterion, until a predetermined length
of the yarn is wound to bring the package 30 into the full winding.
[0108] A transition of the alarm threshold value according to this modification is shown
in the graph of FIG. 5. In this modification, in accordance with the progress of the
yarn winding, the alarm threshold value is switched in two stages, to be changed stepwise.
In this modification in which the alarm threshold value is updated in stages in this
manner, the frequency of re-calculation of the theoretical number of package rotations
and the alarm threshold value can be considerably reduced as compared with in the
above-described embodiment, and therefore this modification is advantageous in that
a load on the theoretical package calculation section 27 and the computation section
17 can be suppressed, and additionally a communication traffic between the machine
control device 11 and the winding unit 16 can be reduced. The number of times the
alarm threshold value is updated is not limited to once, and the alarm threshold value
may be (intermittently) updated at a frequency of twice or three times, or higher.
[0109] As indicated above, in the automatic winder 60 of this modification, the alarm threshold
value is switched in stages in accordance with a change of the theoretical number
of package rotations.
[0110] Thereby, the automatic winder 60 can be operated while the alarm threshold value
is updated in accordance with a state of progress of the yarn winding, without considerably
increasing the load on the theoretical package calculation section 27 and the computation
section 17.
[0111] Next, a second modification of the above-described embodiment will be described.
FIG. 6 is a graph conceptually explaining a relationship between an alarm threshold
value and a package diameter according to the second modification.
[0112] In this modification, the theoretical package diameter is calculated using the winding
length at the time of full-winding. The winding length (a yarn length required for
forming the package) at the time of full-winding is inputted in the machine control
device 11 in advance. The theoretical package calculation section 27 of the second
modification applies this winding length L
F at the time of full-winding to the above-mentioned equation to obtain a theoretical
package diameter D
F with respect to the winding length at the time of full-winding, and calculates the
theoretical number of package rotations in the same manner as described in the above
embodiment. Then, the alarm threshold value is determined by the computation section
17.
[0113] Therefore, in this modification, the alarm threshold value is a constant value throughout
a period from the start to the end of the yarn winding, as shown in FIG. 6. In this
configuration, it suffices that the theoretical number of package rotations and the
alarm threshold value are calculated once, which can further reduce the load on the
theoretical package calculation section 27 and the computation section 17. The theoretical
number of package rotations at the time of full-winding has a constant value as long
as a lot of the package 30 is the same. Therefore, in a case where the same lot of
the package is formed by a plurality of winding units 16, it suffices that a single
alarm threshold value obtained by a single calculation is outputted to the plurality
of winding units 16. Therefore, in this respect as well, the load on the computation
section 17 can be reduced.
[0114] As indicated above, in the automatic winder 60 of this modification, the theoretical
package diameter is the theoretical package diameter at the time of full-winding.
[0115] Therefore, an alarm threshold value applicable under the same yarn winding conditions
can be obtained merely by obtaining, only once, the theoretical number of package
rotations based on this theoretical package diameter. This can simplify a process
performed by the theoretical package calculation section 27 and the computation section
17.
[0116] Although the preferred embodiment and the modifications of the present invention
have been described above, the configurations described above may be modified as follows,
for example.
[0117] There is no problem in determining the alarm threshold value in an arbitrary method,
as long as the determination is based on the theoretical number of package rotations.
For example, instead of determining the alarm threshold value by multiplying the theoretical
number of package rotations by a predetermined ratio, the alarm threshold value may
be determined by subtracting (offsetting) a predetermined value, for example.
[0118] The above-described embodiment is applicable not only to a case where a cone-shaped
package is formed, but also to a case where a cheese-shaped package is formed.
[0119] In the above-described embodiment, the winding unit 16 includes the alarm determination
section 76 and the alarm section 77. However, instead, the machine control device
11 may include the alarm determination section and the alarm section. That is, a configuration
may be acceptable in which: the number of package rotations measured by the package
rotation sensor 72 is outputted to the machine control device 11; the machine control
device 11 collectively performs an alarm determination; and the alarm section of the
machine control device 11 is actuated when an abnormal package rotation is detected.
In this case, a configuration of the winding unit can be simplified as compared with
the configuration in which each winding unit 16 includes the alarm determination section
76 and the alarm section 77.
[0120] In the above-described embodiment, the winding length on the package is measured
by the drum rotation sensor 73 counting the rotation of the traverse drum 41. However,
instead, the winding length may be measured using a yarn speed sensor. This configuration
is shown in FIG. 7. In the description of the configuration of FIG. 7, members identical
or similar to those of the above-described embodiment are denoted by the same corresponding
reference numerals on the drawing, and descriptions thereof may be omitted.
[0121] A yarn speed sensor 65 shown in FIG. 7 is a device which detects a yarn speed by,
utilizing the fact that there is a fluctuation in the yarn thickness in the yarn,
detecting a moving speed of a portion where the fluctuation of the yarn thickness
exists. A signal of this yarn speed is inputted to the unit control section 70, and
the yarn speed is subjected to integral processing in the unit control section 70,
to thereby obtain a winding length. Accordingly, it can be considered that, similarly
to the drum rotation sensor 73, the yarn speed sensor 65 substantially functions as
the winding length measurement section which measure the yarn winding length. Here,
a configuration may be also acceptable in which both the drum rotation sensor 73 and
the yarn speed sensor 65 are provided so that the winding length is measured with
an enhanced accuracy.
[0122] The alarm section 77 may be connected to an equipment which detects not only the
abnormal package rotation mentioned above but also various abnormalities (a mistake
in doffing by the automatic doffing device 51, a mistake in a splicing operation by
the splicing device 14, an abnormality of a power supply, and the like), so that the
alarm is generated also when such abnormalities are detected. In this case, a configuration
for displaying contents of the abnormality using a numerical value or the like may
be provided in the alarm section 77, so that the operator can easily recognize what
kind of event is occurring.
[0123] In the above-described embodiment, the kind of the yarn to be wound and the shape
of the package to be formed are adopted as the yarn winding conditions for obtaining
the relationship (function F) between the yarn winding length and the theoretical
package diameter. However, the theoretical package diameter may be obtained using
other yarn winding conditions.
[0124] In the above-described embodiment, the theoretical package calculation section 27
and the computation section 17 of the machine control device 11 calculate the theoretical
package diameter and the theoretical number of package rotations, to determine the
alarm threshold value. However, instead, the unit control section 70 of each winding
unit 16 may calculate the theoretical package diameter and the theoretical number
of package rotations, to determine the alarm threshold value.
[0125] The application of the above-described embodiment is not limited to an automatic
winder, but may be yarn winding devices such as spinning machine and twisting machines.
DESCRIPTION OF REFERENCE NUMERALS
[0126]
- 11
- machine control device (control section)
- 12
- computation section
- 16
- winding unit
- 27
- theoretical package calculation section
- 60
- automatic winder (yarn winding device)
- 70
- unit control section
- 72
- package rotation sensor (number-of-package-rotations measurement section)
- 73
- drum rotation sensor (winding length measurement section)
- 76
- alarm determination section
- 77
- alarm section