FIELD OF THE INVENTION
[0001] The present invention relates to a spindle actuating controller for a spinning machine
such as a ring spinning machine and a ring thread-plying machine.
RELATED BACKGROUND ART
[0002] A conventional spinning machine of this type has a ring rail which moves vertically
when treated is wound around a bobbin. The winding of thread around a bobbin is carried
out by a traveler (thread guiding member) which moves on a ring flange of the ring
provided on the ring rail. Accordingly, in order to prevent breakage and degradation
of thread quality, it is necessary for the traveler to slide on the ring flange stably
and smoothly. Moreover, it is also necessary to replace the traveler after a predetermined
period of use (typically every 2 or 3 weeks) because it wears due to friction with
the ring flange.
[0003] Generally, when a spinning machine is operated, the spindle rotating speed is increased
gradually in a step-by-step manner rather than as a single step. One conventional
method of changing the spindle rotating speed in a step by step manner is to drive
the spindle actuating motor through an invertor whose frequency can be arranged. According
to this method, the spindle rotating speed or the frequency of the invertor is set
by a speed setting apparatus equipped with a variable resistor. Then, the rotating
speed is adapted to be increased or reduced to the level preset by the speed setting
apparatus when the time elapsed from the start of this machine or the production amount
counted by a counter reaches a predetermined value. Incidentally, in another known
method the spindle rotating speed is changed every 10 % of the production amount when
the bobbins are fully wound with thread (Japanese Unexamined Patent Publication No.
53-41529).
[0004] There is no problem in the conventional methods so long as the spinning machine is
operated under the condition where the spindle is rotated at a maximum speed of 12000
to 16000 rpm. However, if the spindle is rotated at a maximum level of, for example,
20000 to 25000 rpm, the traveler cannot be driven in a stable state. As the result,
thread breakage and damage of the traveler or ring flange are likely to be caused.
Namely, in such a conventional method, the spindle rotating speed is increased to
or reduced from the maximum level through 2 to 3 steps. Accordingly, a fixed speed
gradient is used when the rotating speed of a certain level is increased to a next
step, and such speed change occurs abruptly, so that the tension of thread is suddenly
changed with the change of the rotating speed and the posture of the traveler becomes
unstable causing the problems as described above.
SUMMARY OF THE INVENTION
[0005] Therefore, it is an object of the present invention to provide a spindle actuating
controller for a spinning machine, in which the operational condition can be changed
corresponding to changes in the spinning condition to allow the traveler to always
run smoothly on the ring flange in a stable posture, whereby breakage of thread and
damage of the traveler can be prevented even when the spindle is rotated at a maximum
level of 20000 to 25000 rpm.
[0006] To achieve the object, the present invention a spindle actuating controller is provided
for a spinning machine having a variable speed motor for actuating at least one spindle
in order to wind thread around a bobbin carried by the spindle. The controller includes
a storage device for storing a desired production amount value indicative of the amount
of thread to be wound about the bobbin. It also stores values indicative of the desired
spindle rotating speeds at a plurality of speed change start points and speed change
end points at various points during the winding process. A setting mechanism inputs
the desired production amount value and the desired spindle rotating speeds values
to the storage device. A computing device then calculates speed gradients between
each adjacent pair of speed change points on the basis of information inputted by
the setting mechanism and outputs speed command signals to drive the variable speed
motor at the calculated speed gradients.
[0007] In a preferred arrangement, the production amount is set based on the unit value
of 10 % of that when the bobbins are fully wound with thread, or directly on the length
of thread or the time elapsed. The controller calculates the speed gradients between
every adjacent two speed change points on the basis of the set values, and outputs
speed command signals successively to the actuating controller so as to realize the
calculated speed gradients. Then, speed variable control of the speed variable motor
for actuating the spindles is achieved by the actuating controller. Thus, unlike in
the prior art, the spindle rotating speed is increased or reduced gradually and not
abruptly. Accordingly, the traveler can always run on the ring flange smoothly in
a stable posture without suffering sudden change in the posture, and the thread breakage
and damage of the traveler can be prevented even when the spindle is rotated at a
maximum level of 20000 to 25000 rpm. Moreover, since the spindle rotation speed and
the production amount at each speed change point can arbitrarily be set by the setting
means, and each speed gradient between the adjacent two speed change points can be
automatically set based on the set values, it is possible to set the optimum operational
conditions well adapted to the spinning condition.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008]
Fig. 1 is a schematic view of the present controller;
Fig. 2 is an explanatory diagram showing change of the spindle rotating speed;
Fig. 3(a) through 3(e) are diagrams showing standard patterns of the spindle speed
change in a second embodiment, respectively; and
Fig. 4 is a diagram showing an example of change with time of the spindle rotating
speed in the operative mode for smoothing the spinning after replacement of travelers
in the second embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0009] A first embodiment of the present invention will be described below with reference
to the drawings.
[0010] As shown in Fig. 1, a plurality of spindles 1 are set on both sides of a spinning
machine with at predetermined intervals. A variable speed spindle actuating motor
2 is used to drive the spindles. Specially, a belt 5 extends between and around guide
pulleys 3 and a drive pulley 4 provided on the spindle actuating motor 2, so that
the spindles 1 may be rotated by the spindle actuating motor 2 through the belt 5.
The spindle actuating motor 2 is connected to a controller 6 through an invertor 7,
so that variable speed control of the motor 2 may be achieved based on the output
signals generated from the controller 6 through the invertor 7.
[0011] The controller 6 includes a central processing unit (CPU) 8 and a program memory
9 comprising a read only memory (ROM) which stores control programs. Moreover, the
controller 6 has a memory (RAM) 10 as a storage device which can read and rewrite
for temporarily storing the operational results from the CPU 8, and the production
amounts and the spindle rotating speeds at a plurality of speed change start points
and speed change end points provided within an interval from the start of the spindle
to the state where the spindle is rotated at the maximum level and the interval from
the state where the spindle is rotated at the maximum level of the stoppage of the
spinning machine. The CPU 8 is operated on the basis of the program data stored in
the program memory 9. An input device 11 comprising, for example, a keyboard is provided
as a setting means in the controller 6. By the input device 11, the operation condition
based on the data such as the production amounts and the spindle rotating speeds at
the respective speed change points is set. Furthermore, the CPU 8 is so constructed
that output signals from a rotation detector 12 for detecting the rotation speed of
a front roller of a draft part (not shown) for drawing a roving are inputted to the
CPU 8 through an input-output interface 13.
[0012] The CPU 8 calculates each gradient between adjacent two points on the basis of the
set values of the production amount and the spindle rotating speed at the respective
speed change points inputted from the input device 11 through the input-output interface
13. Then, the CPU 8 outputs a predetermined command signal to the invertor 7 through
the input-output interface 13 and a digital-analog converter (D/A converter) 14. In
response to the command signal, the invertor 7 outputs a frequency signal corresponding
to the calculated gradient to the spindle actuating motor 2.
[0013] Next, the operation of the apparatus constructed as described above will be explained
with reference to Fig. 2. First, an operator sets data concerning the spindle rotating
speed Ni and the production amount Bi at the respective speed change points Pi (i
is a natural number) using the input device 11 on the basis of the unit of 10 % of
the production amount when the bobbins are fully wound so that the spindle rotating
speed may change as desired relative to the production amount correspondingly to the
spinning condition.
[0014] Incidentally, both the spindle rotating speeds N4, N5 at the speed change points
P4, P5 are set at the same maximum value. The CPU 8 calculates each gradient (ΔN/ΔB)
between the adjacent two speed change points Pi, P(i+1) on the basis of the set values
in accordance with the following equation.
ΔN/ΔB = {N(i+1)-Ni} / {B(i+1)-Bi}
[0015] To describe specifically taking the adjacent two change points P3 (20000 rpm, at
the production amount of 40 %) and P4 (25000 rpm, at the production amount of 60 %),
the ΔN/ΔB becomes as follows.
ΔN/ΔB={N(i+1)-Ni} / {B(i+1)-Bi)
=(25000-2000) / (6-4)
= 5000/2
=2500(rpm/10 % of full bobbin)
[0016] Namely, in this case, the gradient obtained is 2500 (rpm/10 % of full bobbin). When
the length of thread is 2200 m at the time of full bobbin, 10 % of the production
amount thereof can be expressed by the thread length of 220 m. Thus, the spindle rotating
speed per meter becomes 2500/220 (rpm/m).
[0017] On the other hand, when a 10-bit unit is used as the D/A converter 14, the minimum
spindle speed variable rotating speed decided by the D/A converter 14 becomes as follows.
(In this case, 1001 to 1024 are not used).
25000 rpm/1000 steps = 25 (rpm/step)
[0018] Next, the length of thread spun during one step is obtained as follows.
Length=220/(2500/25)
=220/100
=2.2 (m/step)
Then, the data are stored in the working memory 10.
[0019] Likewise, all the gradients between the every two adjacent speed change points Pi,
P(i+1) and the lengths of thread spun in the respective steps are calculated, and
the data obtained are stored in the working memory 10. When the spinning machine is
started, the CPU 8 calculates the production amount (the length of thread) on the
basis of the output signals generated from the rotation detector 12. Then, the CPU
8 successively outputs the speed command signal for each step (25 rpm) in response
to each of the speed change data between the respective speed change points stored
in the memory 10, that is, the length of thread spun in each step to the D/A converter
14. The D/A converter 14 converts the digital signal into a current signal and outputs
it to the invertor 7. The invertor 7 drives the spindle actuating motor 2 at a rotating
speed corresponding to the current signal inputted thereto. Namely, the rotating speed
of the spindle actuating motor 2 is not changed greatly at a time, but controlled
so as to change in finely divided steps. However, by the effect of the force of inertia
or the like, the rotating speed shows almost linear change. Accordingly, between the
speed change point P3 and the speed change point P4, the CPU 8 outputs a speed command
signal for one step (25 rpm) every 2.2 m of thread length till the spindle rotating
speed is gradually increased from 20000 rpm to 25000 rpm.
[0020] Accordingly, when the rotating speed of the spindle of the controller in the present
invention is changed, it is gradually changed unlike in the conventional apparatus
in which the rotating speed is rapidly changed. Thus, the traveler can always run
smoothly on the ring flange in a stable posture, preventing thread breakage and the
damage of the traveler or ring. Moreover, the speed change gradient can be automatically
set merely by inputting the spindle rotating speeds or the production amounts at the
respective speed change points. This is done using the input device 11. Therefore,
the optimum speed variable operation condition can easily be set when the spinning
condition is changed. Particularly when the production amount is set on the basis
of the unit of 10 % of the production amount of full bobbin as in the above embodiment,
the operation condition can easily be grasped by the operator, so that the speed change
condition intended by the operator can easily be realized.
[0021] If the invertor 7 is capable of receiving digital inputs, the D/A converter 14 can
be omitted to allow the output signal of the controller 6 to be inputted directly
to the invertor 7. If a section where the spindle rotating speed is set at the same
value between every adjacent two speed change points is provided at the time of setting
the condition of increasing or reducing the speed, it is possible to set a speed change
condition similar to conventional ones. Moreover, when the values of the production
amount at the respective speed change points are set, it is possible to directly set
the length of thread or the process time instead of setting the production amount
on the basis of the unit of 10 % of the production amount of full bobbin.
[Second Embodiment]
[0022] Next, a second embodiment will be explained with reference to Figs. 3 and 4.
[0023] According to this embodiment, it is possible to automatically shift the operative
mode to an ordinary high-speed operative mode after the smoothing operation in the
optimum speed change pattern corresponding to the spinning condition after the installation
of the spinning potion of the spinning machine, and replacement of travelers or rings.
[0024] The constitution of the spindle actuating apparatus is basically the same as that
of the first embodiment, but a mechanism for automatically shifting the smoothing
operative mode to the ordinary high-speed operative mode is added anew. To the controller
6, a doffing completion signal is inputted from a spinning completion detector (not
shown) provided at the spinning machine.
[0025] Moreover, in the program memory 9, a plurality of standard patterns (five patterns
in this embodiment) of the speed change of the spindle actuating motor 2 from the
start to stop of the spinning machine are stored. As shown in Fig. 3, the speed change
standard patterns include a speed change standard pattern M0 for the highest speed
operative mode, and speed change standard patterns M1 to M4 mainly used in the smoothing
operative mode. The speed change pattern M0 for the highest speed operative mode includes
six speed change points P0 to P5 till the rotating speed reaches the highest level
of n4. On the other hand, the speed change pattern M4 includes five speed change points
P0 to P4 till the rotating speed reaches at the highest level of n3, so as to almost
corespond to the speed change of the pattern M0 for the highest speed operative mode.
Moreover, the three speed change patterns M1 to M3 are so set that the spindle rotating
speed may be changed step by step with time. In this case, values of the spindle rotating
speed (ni) in the respective step are so set that it may correspond to the values
of the speed at the respective speed change points in the speed change pattern M4.
Furthermore, the values of the rotating speed at the respective speed change points
and in the respective steps are set at the values already inputted by the input device
11.
[0026] The speed change patterns M0 to M4 after the setting of values of the rotating speed
or speed data at the respective speed change points and in the respective steps are
adapted to be stored in the memory 10. Then, the CPU 8 calculates the gradients between
every adjacent two speed change points and the length of thread spun while the speed
is increased in one step on the basis of values of the rotating speed at the respective
speed change points in the speed change patterns M0 to M4, and the data calculated
are stored in the memory 10. Accordingly, the values of the rotating speed at the
respective speed change points and in the respective steps in the speed change patterns
M0 to M4 can be set independently of other speed change patterns.
[0027] On the other hand, the input device 11 is so constructed that it can select a necessary
speed-change pattern from the speed change patterns M0 to M4 and set the number of
repetition times of the speed change patterns and the output order thereof. Moreover,
the speed change patterns selected, the number of repetition times and the output
order set by the input device 11 are stored in the memory 10. The controller 6 is
adapted to output control signals for controlling the spindle actuating motor 2 to
the invertor 7 on the basis of the program data of the program memory 9 and the speed
data in the speed change patterns stored in the memory 10.
[0028] Next, the operation of the second embodiment so constructed as described above will
be explained. The setting operation of the operation condition changes depending on
whether the smoothing operation is performed or not. In the ordinary spinning operation
without the smoothing operation, the setting of the operation condition is completed
by selecting one of the standard speed change patterns M0 to M4, and setting the speed
data at the respective speed change points and in the respective steps of the selected
speed change pattern in the input device 11. Then, when the operation of the spinning
machine is started, the machine is repeatedly operated by the command from the controller
6 so that the speed change may be realized according to the selected speed change
pattern.
[0029] On the other hand, when the smoothing operation is required, the speed change pattern
M0 for the highest speed operative mode and a speed change pattern whose speed is
lower than that of the pattern M0 on the smoothing operation are selected by the input
device 11. Then the speed data on the respective speed change patterns are set. For
example, when the low-speed speed change patterns M1 to M4 for the low speed operation
are all selected for carving out smoothing operation after replacement of the travelers,
the speed data at the respective speed change points and in the respective steps are
set with respect to all the speed change patterns M0 to M4. In this case, the speed
data at the respective speed change points of the speed change pattern M0 for the
highest speed operation are first set by the input device 11. Thereafter, the speed
data at the respective speed change points and in the respective steps of the speed
change patterns M1 to M4 for the low speed operation are set at the levels corresponding
to the speed data of the respective speed change points in the speed change pattern
M0 for the highest speed operation. Then, the speed change patterns M0 to M4 after
the setting of the speed data are stored in the memory 10, and the numbers of repetition
times of the speed change patterns M0 to M4 after the setting of the speed data are
set. For example, in case of setting the numbers of repetition times of the respective
speed change patterns M1 to M4 are set at 9, 5, 2 and 1, respectively, these data
are stored in the working memory 10, and thus the setting of the operation condition
is completed.
[0030] Thereafter, when the operation of the spinning machine is started after replacement
of the travelers, the controller 6 successively outputs the speed data to the invertor
7 in accordance with the operation condition stored in the working memory 10. Then,
the inventor 7 controls the spindle actuating motor 2 in accordance with the speed
data. The controller 6 counts the input signals from the doffing completion detector
and performs shifting of the speed change pattern whenever the count value reaches
a predetermined value. As shown in Fig. 4, the smoothing spinning operation is carried
out at each selected speed change pattern (M1 to M4) the number of times inputted
by the input device 11. Thereafter, the spinning machine at the highest speed pattern
M0.
[0031] When the highest operational rotating speed of the spindles 1 is at an ultra-high
level of over 18000 rpm, and when it is desired to perform the smoothing operative
mode using a multiplicity of steps, the number of the repetition times of the speed
change patterns can easily be set in different states by the key operation of the
input device 11. After, the smoothing operation is completed using the optimum smoothing
pattern, the ordinary high-speed spinning operation is automatically started.
[0032] Generally, the period of smoothing spinning operation is about 24 hours under the
condition where the highest rotating speed of the spindles 1 is 12000 to 16000 rpm.
However, when the highest rotating speed of the spindles 1 becomes as high as 20000
to 25000 rpm, the period of smoothing spinning operation after replacement of the
travelers requires about 2 to 3 days to make the running posture of the traveler stable.
Moreover, when the highest rotating speed of the spindles 1 is 20000 to 25000 rpm,
the amount of thread to be wound around the bobbins is reduced to 70 to 80 % of that
when the highest rotating speed of the spindles 1 is 10000 to 12000 rpm. Therefore,
doffing of full bobbins is required many times during the period of smoothing spinning
operation. Furthermore, when the highest rotating speed of the spindles 1 is about
14000 to 15000 rpm, it is not necessary to increase stepwise the speed to the maximum
level at the time of the low-speed smoothing operation, before the ordinary high-speed
operation is started. However, when the high-speed operation is carried out at a high
speed of 18000 rpm or more, it is preferred to increase stepwise the speed of the
smoothing operation to the highest level after replacement of the travelers.
[0033] By the way, there is a known method for automatically changing the operative mode
from the smoothing operation to the ordinary spinning operation after the smoothing
operation is conducted at a predetermined low speed for a fixed time set in a timer
or a fixed number of doffing times counted by a counter. However, this method suffers
an inconvenience that it allows only two steps of speed change between high speed
and low speed. On the other hand, in the embodiment according to this invention, the
operative mode can automatically be shifted to the ordinary high-speed operative after
the smoothing operation is so conducted as to successively increase the rotating speed
of the spindles stepwise to the maximum level.
[0034] Depending on the kinds of the travelers used and the spinning condition, it will
not always be necessary to use all the speed change patterns M1 to M4 in the smoothing
operation. Rather the number of the speed change patterns and the number of the repetition
times are selected in accordance with the spinning condition. For example, when the
speed change patterns M1, M3 are selected for the smoothing operation, and the number
of the repetition times of the speed change patterns M1, M3 are respectively set at
2, 5, the speed change pattern M1 is repeated twice, then the pattern M3 is repeated
five times. Subsequently, the speed change pattern M0 for the highest speed operation
is executed.
[0035] Incidentally, while the number of the speed change patterns is five in the above
embodiment, it is not limited to five but should be three or more. Moreover, it is
not necessary to always set the rotating speed at the respective speed change points
and in the respective steps in the low-speed speed change patterns M1 to M4 for the
smoothing operation to correspond to the rotating speed at the respective speed change
points in the highest-speed speed change pattern M0. Further, as the highest-speed
speed change pattern, it is possible to select other speed change patterns than the
speed change pattern M0. Accordingly, it is also possible to use speed change patterns
for the smoothing operation whose speeds are lower than that of the highest-speed
pattern selected in place of the pattern M0. Furthermore, it is possible to set speed
change patterns of the spindle actuating motor 2 by the input device 11 prior to the
operation of the spinning machine instead of storing the standard speed change patterns
in the program memory 9.
[0036] A spindle actuating controller is provided for a spinning machine having a variable
speed motor for actuating spindles in order to wind thread around bobbins carried
by the spindles. The controller calculates desired speed gradients on the basis of
desired spindle rotating speed at various stages in the winding process. The spindle
rotating speed is then increased or reduced gradually and not abruptly. Accordingly,
the traveler can always run on the ring flange smoothly in a stable posture even when
the spindle is rotated at a maximum level of 20000 to 25000 rpm.