BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a static
pressure control method in an automatic winder
including a plurality of winding units capable of
carrying out a yarn joining operation using a suction airflow.
2. Description of the Related Art
An automatic winder including a plurality of
winding units adapted to wind a yarn unwound from a
15 yarn supplying bobbin around a bobbin to form a package
is known. Each winding unit is provided with a yarn
joining device adapted to join a yarn disconnected
between the yarn supplying bobbin and the package.
When carrying out the yarn joining operation, a suction
20 member for an upper yarn adapted to suck and hold a
yarn (upper yarn) from the package and a suction member
for a lower yarn adapted to suck and hold a yarn (lower
yarn) from the yarn supplying bobbin guide the upper
yarn and the lower yarn to the yarn joining device,
25 respectively.
In such an automatic winder, a suction blower
adapted to supply the suction airflow is provided on
the suction member of each winding unit. Yarn waste
accumulates with elapse of time in a flow path
30 connecting the suction blower and each winding unit,
and thus the flow of suction air becomes unsatisfactory,
2 / 33
and the pressure (static pressure) in a duct gradually
lowers. When the static pressure lowers, the suction
force of the suction member lowers, and thus the yarn
joining operation cannot be carried out.
5 To respond to this, the static pressure may be
set high from the beginning in view of the static
pressure lowering, but in this case, the power
consumption of the suction blower increases. Japanese
Laid-Open Utility Model Publication No. 2-40759, for
10 example, discloses a method of detecting the static
pressure of the suction airflow and feedback
controlling the operation of the suction blower based
on the detection value to maintain the static pressure
constant while suppressing the increase in power
15 consumption.
However, if the operation of the suction blower
is merely feedback controlled, the following problems
arise. For example, at the startup of the automatic
winder, a long time is required to match the static
20 pressure of the suction airflow to the set value, and
the power consumption at the beginning of the startup
may increase. Furthermore, even after the automatic
winder is in the normal operation state, the static
pressure may become higher than the set value as the
25 static pressure of the suction airflow hunches
(vibrates), which may become a cause of increase in
power consumption.
BRIEF SUMMARY OF THE INVENTION
30 In light of the foregoing, it is an object of the
present invention to reduce the power consumption of a
3 / 33
suction blower while appropriately controlling a static
pressure of a suction airflow in an automatic winder
including a plurality of winding units capable of
carrying out a yarn joining operation using the suction
5 airflow.
A first aspect of a static pressure control
method in an automatic winder according to the present
invention relates to a static pressure control method
in an automatic winder including a plurality of winding
10 units adapted to carry out a yarn joining operation
using a suction airflow, a suction blower adapted to
generate the suction airflow, and a static pressure
detecting section adapted to detect a static pressure
of the suction airflow, the static pressure control
15 method including a startup process of activating the
suction blower so that a static pressure of the suction
airflow becomes higher than a predetermined set value
at a time of startup of the plurality of winding units;
an initial feedback process of feedback controlling a
20 frequency of the suction blower to lower the static
pressure of the suction airflow to the set value after
the startup process; and a normal feedback process of
feedback controlling the frequency of the suction
blower to maintain the static pressure of the suction
25 airflow at the set value after the initial feedback
process, wherein a control period in the initial
feedback process is shorter than a control period in
the normal feedback process.
At the startup of the automatic winder, the
30 plurality of winding units are started up in order from
the winding unit arranged at the end, and each winding
4 / 33
unit starts the winding after the yarn joining
operation. Thus, if the static pressure of the suction
airflow is deficient at the startup of the automatic
winder, the yarn joining operation may continuously
5 fail, and the winding may not be started. With regards
to this, according to the first aspect of the present
invention, since the suction blower is activated so
that the static pressure of the suction airflow becomes
higher than the set value in the startup process, the
10 static pressure at the time of startup can be increased,
and the yarn joining operation can be reliably carried
out. Furthermore, since the control period in the
initial feedback process immediately after the startup
process is shorter than in the subsequent normal
15 feedback process, the static pressure set high in the
startup process is rapidly lowered to the set value to
match the set value. Therefore, a state in which the
static pressure is higher than the set value is only
for a short time, and the power consumption of the
20 suction blower can be reduced.
In the first aspect of the static pressure
control method in the automatic winder according to the
present invention, a detection period by the static
pressure detecting section in the initial feedback
25 process is preferably shorter than a detection period
in the normal feedback process.
Thus, the static pressure can be more rapidly
matched to the set value by shortening the detection
period of the static pressure in the initial feedback
30 process.
In the first aspect of the static pressure
5 / 33
control method in the automatic winder according to the
present invention, an acceleration/deceleration rate of
the frequency of the suction blower in the initial
feedback process is preferably larger than an
5 acceleration/deceleration rate in the normal feedback
process.
Thus, the static pressure set high in the startup
process can be rapidly lowered to the set value by
increasing the acceleration/deceleration rate of the
10 frequency of the suction blower in the initial feedback
process.
In the first aspect of the static pressure
control method in the automatic winder according to the
present invention, in the startup process, a frequency
15 of the suction blower is first accelerated, and when an
instantaneous value of the static pressure detected by
the static pressure detecting section becomes higher
than or equal to a startup set value set higher than
the set value, a frequency of the suction blower at a
20 time point when the instantaneous value becomes higher
than or equal to the startup set value is maintained
thereafter.
Thus, by controlling the frequency of the suction
blower, the frequency does not need to be changed after
25 the instantaneous value of the static pressure reached
the startup set value, and a simple control program can
be obtained.
In the first aspect of the static pressure
control method in the automatic winder according to the
30 present invention, the process preferably shifts to the
initial feedback process after the startup of the
6 / 33
plurality of winding units is completed in the startup
process.
A state in which the static pressure is high can
be maintained while sequentially starting up the
5 plurality of winding units by shifting to the initial
feedback process after the startup of the plurality of
winding units is completed. Therefore, the yarn
joining operation can be effectively prevented from
failing in the startup process, and the winding can be
10 rapidly started.
In the first aspect of the static pressure
control method in the automatic winder according to the
present invention, when the instantaneous value of the
static pressure detected by the static pressure
15 detecting section becomes smaller than or equal to the
set value in the initial feedback process, the
frequency of the suction blower is preferably
maintained at a frequency of a time point the frequency
of the suction blower becomes smaller than or equal to
20 the set value during the remaining of the control
period.
When lowering the static pressure to the set
value in the initial feedback process, the deceleration
of the frequency of the suction blower is stopped and
25 maintained constant at the time point the instantaneous
value of the static pressure became lower than or equal
to the set value, so that the static pressure can be
suppressed from excessively lowering than the set value.
Therefore, the static pressure can be more rapidly
30 matched with the set value.
In the first aspect of the static pressure
7 / 33
control method in the automatic winder according to the
present invention, when a time average value of the
static pressure detected by the static pressure
detecting section becomes smaller than or equal to the
5 set value in the initial feedback process, the process
shifts to the normal feedback process
The determination of when shifting from the
initial feedback process to the normal feedback process
is made with the time average value instead of the
10 instantaneous value of the static pressure, whereby the
shift is made to the normal feedback process after the
static pressure is more accurately matched with the set
value in the initial feedback process.
A second aspect of a static pressure control
15 method in an automatic winder according to the present
invention relates to a static pressure control method
in an automatic winder including a plurality of winding
units adapted to carry out a yarn joining operation
using a suction airflow, a suction blower adapted to
20 generate the suction airflow, and a static pressure
detecting section adapted to detect a static pressure
of the suction airflow, the static pressure control
method including the steps of feedback controlling a
frequency of the suction blower to maintain a static
25 pressure of the suction airflow at a predetermined set
value; starting to accelerate the frequency of the
suction blower when a time average value of the static
pressure detected by the static pressure detecting
section is smaller than the set value; and stopping the
30 acceleration of the frequency of the suction blower at
a time point when an instantaneous value of the static
8 / 33
pressure detected by the static pressure detecting
section becomes higher than or equal to the set value.
According to the second aspect of the present
invention, the determination of when to stop the
5 acceleration of the frequency of the suction blower is
made with the instantaneous value instead of the time
average value of the static pressure, whereby the
static pressure can be effectively prevented from
rising beyond the set value and the power consumption
10 of the suction blower can be reduced.
An automatic winder according to the present
invention includes a plurality of winding units adapted
to carry out a yarn joining operation using a suction
airflow; a suction blower adapted to generate the
15 suction airflow; a static pressure detecting section
adapted to detect a static pressure of the suction
airflow; and a control section adapted to control
operation of the suction blower based on the static
pressure detected by the static pressure detecting
20 section, wherein the control section executes any
static pressure control method in the automatic winder
described above.
The power consumption of the suction blower can
25 be reduced in the automatic winder including such a
control section.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of an automatic winder
30 according to the present embodiment;
FIG. 2 is a block diagram illustrating an
9 / 33
electrical configuration of the automatic winder;
FIG. 3 is a front view of a winding unit;
FIG. 4 is a top view schematically illustrating a
yarn waste collecting device;
5 FIG. 5 is a flowchart illustrating a series of
operations after the startup of the automatic winder;
FIG. 6 is a flowchart illustrating an initial
feedback control;
FIG. 7 is a flowchart illustrating a normal
10 feedback control; and
FIG. 8 is a graph illustrating change in a blower
frequency and static pressure.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
15 (Automatic winder) An embodiment of the present
invention will now be described. FIG. 1 is a front
view of an automatic winder according to the present
embodiment, FIG. 2 is a block diagram illustrating an
electrical configuration of the automatic winder, and
20 FIG. 3 is a front view of a winding unit. As
illustrated in FIG. 1, the automatic winder 1 includes
a plurality of winding units 2 arrayed in a
predetermined array direction (left and right direction
of FIG. 1 ) , a doffing device 3 arranged to freely
25 travel in the left and right direction, a yarn waste
collecting box 4 arranged on the left side of the
plurality of winding units 2, and a machine control
device 5 adapted to control each section.
As illustrated in FIG. 2, the machine control
30 device 5, a unit control section 2a of each winding
unit 2, and the doffing device 3 are configured to be
10 / 33
able to transmit/receive electric signals with each
other. After the formation of a package P, that is,
the winding of the yarn Y is completed in a winding
unit 2, a winding complete signal is transmitted from
5 the unit control section 2a of the relevant winding
unit 2 to the doffing device 3. The doffing device 3
that received the winding complete signal moves to the
relevant winding unit 2 to carry out the doffing
operation.
10 (Winding unit) As illustrated in FIG. 3, the
winding unit 2 winds a yarn Y unwound from a yarn
supplying bobbin B around a winding tube Q to form the
package P. The winding unit 2 includes a yarn
supplying section 10 adapted to supply the yarn Y wound
15 around the yarn supplying bobbin B while unwinding, a
yarn processing section 20 adapted to carry out various
processes on the yarn Y supplied from the yarn
supplying section 10, and a winding section 30 adapted
to wind the yarn Y that passed the yarn processing
20 section 20 around the winding tube Q to form the
package P. The yarn supplying section 10, the yarn
processing section 20, and the winding section 30 are
arranged in such order from the bottom to the top.
The yarn supplying section 10 includes a yarn
25 unwinding assisting device 11 adapted to assist the
unwinding of the yarn Y when unwinding the yarn Y from
the yarn supplying bobbin B held in a standing state.
The yarn unwinding assisting device 11 includes a
regulation tube 12 adapted to regulate the bulge
30 (balloon) of when the yarn Y is being unwound to an
appropriate range.
11 / 33
The yarn processing section 20 includes a yarn
filler 21, a tension applying device 22, a yarn joining
device 23, a yarn clearer 24, a lower yarn catching and
guiding member 25, an upper yarn catching and guiding
5 member 26, and the like.
The yarn filler 21 is adapted to detect the
presence and absence of the travelling yarn Y between
the yarn unwinding assisting device 11 and the tension
applying device 22. The tension applying device 22 is
10 adapted to apply a predetermined tension on the
travelling yarn Y. In FIG. 3, a so-called gate type
tension applying device is illustrated by way of
example. The yarn clearer 24 acquires the information
on the thickness of the travelling yarn Y on a steady
15 basis, and detects an abnormal portion, where a yarn
thickness is thick or greater than or equal to a
constant thickness, included in the yarn Y as a yarn
defect based on the information on the yarn thickness.
A cutter 24a is arranged in the yarn clearer 24, where
20 the yarn Y is immediately cut with the cutter 24a when
the yarn defect is detected by the yarn clearer 24.
The yarn joining device 23 joins a lower yarn Y1
from the yarn supplying bobbin B and an upper yarn Y2
from the package P when the yarn defect is detected by
25 the yarn clearer 24 and the yarn is cut by the cutter
24a, when yarn breakage occurs during the winding of
the package P, or when replacing the yarn supplying
bobbin B. An example of the yarn joining device 23 is
a splicer adapted to generate an airflow to entangle
30 the fibers of the lower yarn Y1 and the upper yarn Y2
and carry out the yarn joining operation. The yarn
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defect remains in the upper yarn Y2 even if the yarn Y
is cut by the cutter 24a after the yarn defect
detection by the yarn clearer 24. Thus, the yarn
joining device 23 carries out the yarn joining
5 operation of the lower yarn Y1 and the upper yarn Y2
after removing the yarn defect using a built-in cutter
(not illustrated).
The lower yarn catching and guiding member 25
sucks and catches the lower yarn Y1 from the yarn
10 supplying bobbin B and guides the lower yarn Y1 to the
yarn joining device 23. The lower yarn catching and
guiding member 25 is rotationally driven by a motor 27
to pivot up and down with a shaft 25a as the center. A
distal end portion of the lower yarn catching and
15 guiding member 25 is provided with a suction portion
25b adapted to suck and catch a yarn end of the lower
yarn Y1. The upper yarn catching and guiding member 26
sucks and catches the upper yarn Y2 from the package P
and guides the upper yarn Y2 to the yarn joining device
20 23. The upper yarn catching and guiding member 26 is
rotationally driven by the motor 28 to pivot up and
down with a shaft 26a as the center. A distal end
portion of the upper yarn catching and guiding member
26 is provided with a suction portion 26b adapted to
25 suck and catch a yarn end of the upper yarn Y2. The
lower yarn catching and guiding member 25 and the upper
yarn catching and guiding member 26 are connected to
the yarn waste collecting device 6 (see FIG. 4 ) , to be
described later, and configured to generate suction
30 airflow at the suction portion 25b, 26b.
The yarn joining operation in the winding unit 2
13 / 33
is carried out in the following manner. The upper yarn
catching and guiding member 26 first pivots upward, and
sucks and catches the yarn end of the upper yarn Y2
attached to the surface of the package P with the
5 suction portion 26b. Then, the upper yarn catching and
guiding member 26 pivots downward while catching the
upper yarn Y2 to guide the upper yarn Y2 to the yarn
joining device 23. The lower yarn catching and guiding
member 25 pivots upward while catching the yarn end of
10 the lower yarn Y1 with the suction portion 25b to guide
the lower yarn Y1 to the yarn joining device 23. The
yarn joining device 23 then connects the yarn end of
the lower yarn Y1 introduced by the lower yarn catching
and guiding member 25 and the yarn end of the upper
15 yarn Y2 introduced by the upper yarn catching and
guiding member 26 to form one yarn Y.
The winding section 30 includes a cradle 31,
which supports the winding tube Q in a freely rotating
manner, a traverse drum 32, and a drum drive motor 33
20 adapted to rotate the traverse drum 32. A spiralshaped
traverse groove 32a is formed on a peripheral
surface of the traverse drum 32, which traverse groove
32a traverses the yarn Y. When the traverse drum 32
rotates while making contact with the package P, the
25 yarn Y can be wound into the package P while traversing.
(Yarn waste colleting device) FIG. 4 is a top
view schematically illustrating the yarn waste
collecting device 6. The yarn waste collecting device
6 collects the yarn waste produced in the plurality of
30 winding units 2. The yarn waste collecting device 6
includes a yarn waste collecting box 4, a suction
14 / 33
blower 41 and a filter 42 arranged in the yarn waste
collecting box 4, and a duct 43 that connects the yarn
waste collecting box 4 and the plurality of winding
units 2. The duct 43 is arranged behind the plurality
5 of winding units 2. The duct 43 is provided with a
static pressure sensor 46 adapted to detect the static
pressure of the suction airflow in the duct 43. In the
present embodiment, the static pressure sensor 46 is
provided at an upstream end of the duct 43 in a
10 direction the suction airflow flows. However, the
static pressure sensor 46 may be provided at other
portions of the duct 43, and may be provided on the
duct 43 side than the filter 42 in an interior space of
the yarn waste collecting box 4.
15 The upper yarn catching and guiding member 26 of
the winding unit 2 is connected to the duct 43 by way
of a piping 51. The piping 51 is provided with a
shutter 52, which operation is controlled by the unit
control section 2a. The upper yarn catching and
20 guiding member 26 can be switched to a state of acting
the suction airflow and a state of not acting the
suction airflow by opening and closing the shutter 52.
When the yarn joining operation is executed, the yarn Y
can be sucked by the upper yarn catching and guiding
25 member 26 by opening the shutter 52. The lower yarn
catching and guiding member 25 is connected to the duct
43 by way of a piping 53. An open/close lid (not
illustrated) is provided at the suction portion 25b
(see FIG. 3) of the lower yarn catching and guiding
30 member 25. The open/close lid makes contact with a
pushing member (not illustrated) at a lower yarn
15 / 33
catching position where the lower yarn catching and
guiding member 25 catches the yarn end of the lower
yarn Y1. The open/close lid thereby opens, and the
suction action can be made.
5 In order to stabilize the yarn joining operation
in the winding unit 2, the static pressure (suction
force) of the suction airflow in the duct 43 is
desirably maintained at a predetermined set value P1.
However, if the yarn waste accumulates in the filter 42
10 and the duct 43, the static pressure in the duct 43
lowers, the suction force of the lower catching and
guiding member 25 and the upper yarn catching and
guiding member 26 weakens, and the yarn joining
operation is likely to fail. Thus, in the present
15 embodiment, a frequency (rotation number) of the
suction blower 41 is feedback controlled based on the
detection value of the static pressure sensor 46 so as
to maintain the static pressure in the duct 43 to the
set value P1. Thus, even if the yarn waste accumulates
20 in the filter 42 and the duct 43, the static pressure
in the duct 43 can be maintained at the set value P1.
(Static pressure control) The static pressure
control of the suction airflow by the machine control
device 5 will be described in detail with reference to
25 FIGS. 5 to 8. FIG. 5 is a flowchart illustrating a
series of operations after the startup of the automatic
winder 1, FIG. 6 is a flowchart illustrating an initial
feedback control, FIG. 7 is a flowchart illustrating a
normal feedback control, and FIG. 8 is a graph
30 illustrating change in blower frequency and static
pressure. A vertical line of a chain line illustrated
16 / 33
in the graph of FIG. 8 indicates the start time of the
control period of the feedback control, and an interval
of the chain lines corresponds to the control period.
Furthermore, although illustrated in a simplified
5 manner in FIG. 8, actually, fine vibration (hunching)
is typically generated at the instantaneous value
(detection value itself) of the static pressure.
As illustrated in FIG. 5, the machine control
device 5 first accelerates the frequency of the suction
10 blower 41 (hereinafter referred to as “blower
frequency”) at the startup of the automatic winder 1
(see step S11, time t0 to t1 of FIG. 8 ) . The
acceleration of the blower frequency is stopped when
the instantaneous value (detection value itself) of the
15 static pressure (force per unit area acting in a
perpendicular direction with respect to the direction
of flow, hereinafter referred to as “static pressure”)
of the suction airflow in the duct 43 becomes higher
than or equal to a predetermined startup set value P2
20 (YES in step S12, see time t1 of FIG. 8 ) . The
subsequent blower frequency is maintained at the
frequency the instantaneous value reached the startup
set value P2, and the plurality of winding units 2 are
sequentially started up (sequential startup) from the
25 end (step S13, see times t1 to t2 of FIG. 8 ) . Steps
S11 to S13 correspond to “startup process” of the
present invention.
The startup set value P2 is set to a value higher
than the set value P1 in the initial feedback process
30 and the normal feedback process, to be described later.
Thus, the static pressure is made higher in the startup
17 / 33
process than at the time of the normal operation
because the yarn joining operation is simultaneously
executed in a great number of winding units 2 when
sequentially starting up the plurality of winding units
5 2. Even if the yarn joining operation is
simultaneously executed in a great number of winding
units 2 by making the static pressure in the startup
process high, the deficiency in the suction force can
be prevented from occurring.
10 When the startup of all the winding units 2 is
completed (YES in step S14), that is, when the winding
of the yarn Y is started in all the winding units 2,
the possibility the yarn joining operation will be
simultaneously executed in a great number of winding
15 units 2 becomes low. Thus, the machine control device
5 executes the initial feedback control to rapidly
lower the static pressure made higher than the set
value P1 in the startup process to the set value P1
(step S15). The initial feedback control is executed
20 during time t2 to t4 of FIG. 8, and corresponds to the
“initial feedback process” of the present invention.
After the static pressure lowered to the set value P1
in the initial feedback control, the machine control
device 5 executes the normal feedback control to
25 maintain the static pressure to the set value P1 (step
S16). The normal feedback control is executed after
time t4 of FIG. 8, and corresponds to the “normal
feedback process” of the present invention. The
initial feedback control and the normal feedback
30 control will be hereinafter described in detail.
(Initial feedback control) As illustrated in FIG.
18 / 33
6, in the initial feedback control, whether or not a
time average value (hereinafter referred to as “average
value”) of the static pressure in the control period
one before is higher than the set value P1 is first
5 determined (step S21). Immediately after the start of
the initial feedback, the average value of the static
pressure is higher than the set value P1 (YES in step
S21), and thus the blower frequency decelerates at a
constant deceleration rate (step S22). The
10 instantaneous value of the static pressure is detected
at an interval shorter than the control period by the
static pressure sensor 46. As illustrated in time t2
to t3 of FIG. 8, the instantaneous value of the static
pressure also lowers proportionally accompanying the
15 deceleration of the blower frequency. In step S23,
whether or not the instantaneous value of the static
pressure detected by the static pressure sensor 46
lowered to lower than or equal to the set value P1 is
determined. When the instantaneous value is still
20 higher than the set value P1 (NO in step S23), and the
control period has not elapsed (NO in step S24), the
deceleration of the blower frequency is continued (step
S22). When the control period has elapsed (YES in step
S24), the process returns to step S21 and the next
25 control period is started based on the new average
value.
In step S23, when the instantaneous value of the
static pressure becomes lower than or equal to the set
value P1 (YES in step S23, see time t3 of FIG. 8 ) , the
30 deceleration of the blower frequency is stopped and
maintained constant during the remaining of the control
19 / 33
period (step S25). When the control period has elapsed
(YES in step S26), the process returns to step S21 and
the next control period is started based on the new
average value. Thus, the static pressure can be
5 prevented from becoming too low beyond the set value P1
and the matching with the set value P1 can be rapidly
carried out by determining the stop timing of the
deceleration of the blower frequency with the
instantaneous value instead of the average value of the
10 static pressure.
When the average value of the static pressure
becomes lower than or equal to the set value P1 (NO in
step S21, see time t4 of FIG. 8) while repeating steps
S21 to S26, the initial feedback control is terminated
15 and the process shifts to the normal feedback control.
When making the determination of the shift from the
initial feedback process to the normal feedback process
with the instantaneous value of the static pressure,
for example, the shift is made to the normal feedback
20 process at time t3. The shift is made to the normal
feedback process of long control period, as will be
described later, in a state where the average value of
the static pressure is higher than the set value P1.
In this case, a long time may be required to match the
25 static pressure to the set value P1, and thus the
determination of the shift is made with the average
value rather than the instantaneous value in the
present embodiment.
In the present embodiment, the control period in
30 the initial feedback control is made shorter than the
control period in the normal feedback control described
20 / 33
next. Furthermore, the detection period of the static
pressure by the static pressure sensor 46 in the
initial feedback control is made shorter than the
detection period in the normal feedback control.
5 Furthermore, the acceleration/deceleration rate of the
blower frequency in the initial feedback control is
made larger than the acceleration/deceleration rate of
the blower frequency in the normal feedback control.
In this manner, the static pressure can be rapidly
10 matched with the set value P1 in the initial feedback
process. In the present embodiment, the control period
in the initial feedback control is 10 seconds, the
detection period of the static pressure is one second,
and the acceleration/deceleration of the blower
15 frequency is 0.3 Hz/second. On the other hand, the
control period in the normal feedback control is 300
seconds, the detection period of the static pressure is
15 seconds, and the acceleration/deceleration of the
blower frequency is 0.001 Hz/second. These values are
20 merely one example, for example, and can be
appropriately changed.
(Normal feedback control) As illustrated in FIG.
7, in the normal feedback control, whether or not an
average value of the static pressure in the control
25 period one before is lower than the set value P1 is
first determined (step S31). When the average value of
the static pressure is lower than the set value P1 (YES
in step S31, see time t5 of FIG. 8 ) , the blower
frequency is accelerated at a constant acceleration
30 rate (step S32). As illustrated in time t5 to t6 of
FIG. 8, the instantaneous value of the static pressure
21 / 33
also rises proportionally accompanying the acceleration
of the blower frequency. However, the
acceleration/deceleration rate in the normal feedback
control is smaller than the acceleration/deceleration
5 rate in the initial feedback control, and thus the
rising speed of the static pressure is gradual.
In step S33, whether or not the instantaneous
value of the static pressure detected by the static
pressure sensor 46 reached the set value P1 is
10 determined. When the instantaneous value is still
lower than the set value P1 (NO in step S33), and the
control period has not elapsed (NO in step S34), the
acceleration of the blower frequency is continued (step
S32). When the control period has elapsed (YES in step
15 S34), the process returns to step S31 and the next
control period is started based on the new average
value.
In step S33, when the instantaneous value of the
static pressure reaches the set value P1 (YES in step
20 S33, see time t6 of FIG. 8 ) , the acceleration of the
blower frequency is stopped and maintained constant
during the remaining of the control period (step S35).
When the control period has elapsed (YES in step S36),
the process returns to step S31 and the next control
25 period is started based on the new average value. Thus,
the static pressure can be prevented from rising beyond
the set value P1 and the useless power consumption can
be reduced by determining the stop timing of the
acceleration of the blower frequency with the
30 instantaneous value instead of the average value of the
static pressure.
22 / 33
When the average value of the static pressure is
higher than or equal to the set value P1 in step S31
(NO in step S31), on the other hand, the blower
frequency is decelerated at a constant deceleration
5 rate during the control period (step S37). When the
control period has elapsed (YES in step S38), the
process returns to step S31 and the next control period
is started based on the new average value.
(Effect) In the present embodiment, the control
10 period in the initial feedback process (initial
feedback control) is made shorter than the control
period in the normal feedback process (normal feedback
control). Therefore, the static pressure set high in
the startup process (at the time of sequentially
15 starting up a plurality of winding units 2) can be
rapidly lowered to the set value P1 to match the set
value P1. Therefore, a state in which the static
pressure is higher than the set value P1 is only for a
short time, and the power consumption of the suction
20 blower 41 can be reduced. Conventionally, the process
shifted to the normal feedback process of long control
period after the startup process, but in this case,
about 20 minutes were required to match the static
pressure to the set value P1. When operated under the
25 conditions of the present embodiment, on the other hand,
the matching of the static pressure completed in about
one minute.
In the present embodiment, the detection period
by the static pressure sensor 46 (corresponds to
30 “static pressure detecting section” of the present
invention” in the initial feedback process is made
23 / 33
shorter than the detection period in the normal
feedback process. Thus, the static pressure can be
more rapidly matched to the set value P1 by shortening
the detection period of the static pressure in the
5 initial feedback process.
In the present embodiment, the
acceleration/deceleration rate of the blower frequency
in the initial feedback process is made larger than the
acceleration/deceleration rate in the normal feedback
10 process. Thus, the static pressure set high in the
startup process can be rapidly lowered to the set value
P1 by increasing the acceleration/deceleration rate of
the frequency of the suction blower in the initial
feedback process.
15 In the present embodiment, in the startup process,
the blower frequency is first accelerated (see time t0
to t1 of FIG. 8 ) , and when the instantaneous value of
the static pressure detected by the static pressure
sensor 46 becomes higher than or equal to the startup
20 set value P2 set higher than the normal set value P1
(see time t1 of FIG. 8 ) , the blower frequency at the
time point the instantaneous value became higher than
or equal to the startup set value P2 is maintained
thereafter (see time t1 to t2 of FIG. 8 ) . Thus, by
25 controlling the blower frequency, the frequency does
not need to be changed after the instantaneous value of
the static pressure reached the startup set value P2,
and a simple control program can be obtained.
In the present embodiment, in the startup process,
30 the process shifts to the initial feedback process when
the startup of the plurality of winding units 2 is
24 / 33
completed (see time t2 of FIG. 8 ) . Thus, the state of
high static pressure can be maintained while
sequentially starting up the plurality of winding units
2. Therefore, the yarn joining operation can be
5 effectively prevented from failing in the startup
process, and the winding can be rapidly started.
In the present embodiment, in the initial
feedback process, when the instantaneous value of the
static pressure detected by the static pressure sensor
10 46 becomes lower than or equal to the set value P1 (see
time t3 of FIG. 8 ) , the blower frequency is maintained
at the frequency at the time point the instantaneous
value became lower than or equal to the set value P1
during the remaining of the control period. When
15 lowering the static pressure to the set value P1 in the
initial feedback process, the deceleration of the
blower frequency is stopped and maintained constant at
the time point the instantaneous value of the static
pressure became lower than or equal to the set value P1,
20 so that the static pressure can be suppressed from
excessively lowering than the set value P1. Therefore,
the static pressure can be more rapidly matched with
the set value P1.
In the present embodiment, in the initial
25 feedback process, when the average value of the static
pressure detected by the static pressure sensor 46
becomes lower than or equal to the set value P1 (see
time t4 of FIG. 8 ) , the process shifts to the normal
feedback process. The determination of when shifting
30 from the initial feedback process to the normal
feedback process is made with the average value instead
25 / 33
of the instantaneous value of the static pressure,
whereby the shift is made to the normal feedback
process after the static pressure is more accurately
matched with the set value P1 in the initial feedback
5 process.
In the present embodiment, the blower frequency
starts to accelerate when the average value of the
static pressure detected by the static pressure sensor
46 is lower than the set value P1 (see time t5 of FIG.
10 8 ) , and the acceleration of the blower frequency is
stopped at the time point the instantaneous value of
the static pressure detected by the static pressure
sensor 46 becomes higher than or equal to the set value
P1 (see time t6 of FIG. 8 ) . Thus, the determination of
15 when to stop the acceleration of the blower frequency
is made with the instantaneous value instead of the
average value of the static pressure, whereby the
static pressure can be effectively prevented from
rising beyond the set value P1 and the power
20 consumption of the suction blower 41 can be reduced.
(Other Embodiment) Alternative embodiments in
which various modifications are made on the embodiment
described above will be described.
In the above-described embodiment, in the startup
25 process, the suction blower 41 is controlled so that
the blower frequency of a time point the instantaneous
value of the static pressure reached the startup set
value P2 is maintained. However, the control method of
the suction blower 41 in the startup process is not
30 limited thereto. For example, in the startup process,
the blower frequency may be maintained at a certain
26 / 33
constant value from the beginning. The constant value
in this case is merely a frequency that can realize a
static pressure that does not affect the sequential
startup of the plurality of winding units 2, and may be
5 an upper limit value of the frequency of the suction
blower 41 by way of example.
In the above-described embodiment, when the
startup of all the winding units 2 is completed, the
process shifts from the startup process to the initial
10 feedback process. However, the process may shift from
the startup process to the initial feedback process at
the time point the startup of some winding units 2 is
not yet completed.
In the above-described embodiment, the
15 acceleration rate and the deceleration rate in each
feedback process are the same. However, the
acceleration rate and the deceleration rate may be
different. In particular, when focusing on reducing
the power consumption of the suction blower 41 as in
20 the present embodiment, the deceleration rate is
preferably set larger than the acceleration rate.
In the above-described embodiment, the set value
P1 of the static pressure is set to a single value.
However, the set value P1 of the static pressure may be
25 set as a value within a constant range.
In the above-described embodiment, the control of
the suction blower 41 is carried out by the machine
control device 5. However, the control of the suction
blower 41 may be carried out by another control section.
30 In the above-described embodiment, the shift from
the startup process to the initial feedback process and
27 / 33
the shift from the initial feedback process to the
normal feedback process are automatically carried out
by the machine control device 5. However, such shift
may be carried out by the operation of an operator.
5 In the above-described embodiment, a winding
complete signal is directly transmitted from the unit
control section 2a of the winding unit 2 to the doffing
device 3. However, the winding complete signal may be
transmitted from the unit control section 2a of the
10 winding unit 2 to the machine control device 5, and a
doffing command of instructing in which winding unit 2
to carry out the doffing operation may be transmitted
from the machine control device 5 to the doffing device 3.

WE CLAIM:
1. A static pressure control method in an
automatic winder (1) including a plurality of winding
units (2) adapted to carry out a yarn joining operation
5 using a suction airflow, a suction blower (41) adapted
to generate the suction airflow, and a static pressure
detecting section (46) adapted to detect a static
pressure of the suction airflow, the static pressure
control method comprising:
10 a startup process (S11 to S13) of activating the
suction blower (41) so that a static pressure of the
suction airflow becomes higher than a predetermined set
value (P1) at a time of startup of the plurality of
winding units (2);
15 an initial feedback process (S15) of feedback
controlling a frequency of the suction blower (41) to
lower the static pressure of the suction airflow to the
set value (P1) after the startup process (S11 to S13);
and
20 a normal feedback process (S16) of feedback
controlling the frequency of the suction blower (41) to
maintain the static pressure of the suction airflow at
the set value (P1) after the initial feedback process
(S15),
25 characterized in that a control period in the
initial feedback process (S15) is shorter than a
control period in the normal feedback process (S16).
2. The static pressure control method in the
30 automatic winder (1) according to claim 1,
characterized in that a detection period by the static
29 / 33
pressure detecting section (46) in the initial feedback
process (S15) is shorter than a detection period in the
normal feedback process (S16).
5 3. The static pressure control method in the
automatic winder (1) according to claim 1 or 2,
characterized in that an acceleration/deceleration rate
of the frequency of the suction blower (41) in the
initial feedback process (S15) is larger than an
10 acceleration/deceleration rate in the normal feedback
process (S16).
4. The static pressure control method in the
automatic winder (1) according to any one of claims 1
15 to 3, characterized in that in the startup process (S11
to S13), a frequency of the suction blower (41) is
first accelerated, and when an instantaneous value of
the static pressure detected by the static pressure
detecting section (46) becomes higher than or equal to
20 a startup set value (P2) set higher than the set value
(P1), a frequency of the suction blower (41) at a time
point when the instantaneous value becomes higher than
or equal to the startup set value (P2) is maintained
thereafter.
25
5. The static pressure control method in the
automatic winder (1) according to any one of claims 1
to 4, characterized in that the process shifts to the
initial feedback process (S15) after the startup of the
30 plurality of winding units (2) is completed in the
startup process (S11 to S13).
30 / 33
6. The static pressure control method in the
automatic winder (1) according to any one of claims 1
to 5, characterized in that when the instantaneous
5 value of the static pressure detected by the static
pressure detecting section (46) becomes smaller than or
equal to the set value (P1) in the initial feedback
process (S15), the frequency of the suction blower (41)
is maintained at a frequency of a time point when the
10 instantaneous value becomes smaller than or equal to
the set value (P1) during the remaining of the control
period.
7. The static pressure control method in the
15 automatic winder (1) according to any one of claims 1
to 6, characterized in that when a time average value
of the static pressure detected by the static pressure
detecting section (46) becomes smaller than or equal to
the set value (P1) in the initial feedback process, the
20 process shifts to the normal feedback process (S16).
8. A static pressure control method in an
automatic winder (1) including a plurality of winding
units (2) adapted to carry out a yarn joining operation
25 using a suction airflow, a suction blower (41) adapted
to generate the suction airflow, and a static pressure
detecting section (46) adapted to detect a static
pressure of the suction airflow, the static pressure
control method characterized by comprising the steps
30 of:
feedback controlling a frequency of the suction
31 / 33
blower (41) to maintain a static pressure of the
suction airflow at a predetermined set value (P1); and
starting acceleration of the frequency of the
suction blower (41) when a time average value of the
5 static pressure detected by the static pressure
detecting section (46) is smaller than the set value
(P1), and stopping the acceleration of the frequency of
the suction blower (41) at a time point when an
instantaneous value of the static pressure detected by
10 the static pressure detecting section (46) becomes
higher than or equal to the set value (P1).
9. An automatic winder (1) comprising:
a plurality of winding units (2) adapted to carry
15 out a yarn joining operation using a suction airflow;
a suction blower (41) adapted to generate the
suction airflow;
a static pressure detecting section (46) adapted
to detect a static pressure of the suction airflow; and
20 a control section adapted to control operation of
the suction blower (41) based on the static pressure
detected by the static pressure detecting section (46),
characterized in that the control section
executes the static pressure control method in the
25 automatic winder (1) according to any one of claims 1 to 8.